ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Articles  (3,958)
  • International Union of Crystallography (IUCr)  (3,958)
  • 1995-1999
  • 1980-1984  (1,211)
  • 1975-1979  (2,747)
  • 1984  (1,211)
  • 1978  (1,489)
  • 1976  (1,258)
Collection
  • Articles  (3,958)
Source
Publisher
Years
  • 1995-1999
  • 1980-1984  (1,211)
  • 1975-1979  (2,747)
Year
Topic
  • 1
    Electronic Resource
    Electronic Resource
    A low-temperature apparatus for single-crystal diffractometry. The unit-cell dimension of α-quartz in the temperature range 86–298 K (1976)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 9 (1976), S. 14-17 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A detailed description of an automatic low-temperature apparatus to be used in single-crystal diffractometry is given. The crystal is cooled by a stream of nitrogen gas. Prevention of ice formation on the crystal is achieved by heating the outer parts of the gas stream by a conical metal device. The unit-cell dimensions of α-quartz have been determined in the temperature range 86–298 K with this apparatus on a four-circle diffractometer of type CAD-4.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889876010418
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Stereographic X-ray reflection topography of dislocations in zinc (1976)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 9 (1976), S. 34-38 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: X-ray reflection topographs were taken of a zinc surface oriented about 1° from a basal plane. Basal dislocations are revealed in the topographs, and their apparent depth was determined using stereo pairs of topographs. The apparent depths observed in a complimentary pair of topographs using 10\bar 13 and \bar 1013 reflections were significantly greater than those observed in an asymmetric pair of topographs in which the same 10\bar 13 reflection was used. This difference is attributed to shifts of the image with respect to the dislocation position. Quantitative estimates of the image shifts and the actual depths of the observed dislocations are obtained from the measurement of apparent depths. Dislocations are visible over the range of depths from 1.7 to 4.5 μm.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889876010443
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Computer programs for radial distribution analyses of X-ray and electron diffraction data (1976)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 9 (1976), S. 253-254 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A set of Fortran programs for radial distribution function analyses of X-ray and electron diffraction data of liquid and amorphous samples is available. The programs relate, first, to the formation of a reduced intensity function, F(K) ≡ (I − 〈f2〉)/〈f〉2, where I is the coherent scattered intensity in electron units, K is 4π sin &thgr;/λ, and 〈f〉 is the average of the scattering factors. The experimental radial distribution function G(r) = 4πr[ρ(r)−ρ0], is derived as the Fourier sine integral of F(K).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889876011163
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Reliability in automated flatbed microdensitometers (1976)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 9 (1976), S. 257-258 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889876011199
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    The detection of small differences in lattice constant at low temperature by an energy-dispersive X-ray diffractometer (1976)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 9 (1976), S. 286-290 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A cryostat has been designed for an energy-dispersive X-ray diffractometer so that the specimen can be measured between 1.48 K and room temperature. Three powder samples can successively be measured at a fixed temperature by rotating the cryostat in steps of 120°. This design is very suitable particularly for detecting a slight change or difference, if any, in lattice constant among samples. A typical example is described of detecting the difference in lattice constant between 92Mo and 100Mo.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889876011370
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    A general, weighted least-squares method for the evaluation of small-angle X-ray data without desmearing (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 73-79 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: In order to avoid some of the disadvantages associated with the desmearing methods, a procedure has been developed where the smeared, primary, intensity data can be evaluated directly without desmearing. The procedure consists of the following: first, a model depending on a vector of unknowns, x = (x1, ...., xn), is constructed; then, an iterative search is made for the vector x, and a scale factor s, which corresponds to a local minimum in the error square sum based on the primary, slit-smeared, intensity data. The main advantages with the present method are that the comparison between theory and experiment is made directly with the experimental quantity; thus the experimental errors can be considered in this comparison. Furthermore, some of the disadvantages associated with the desmearing methods are avoided; the method is numerically stable and no extrapolations outside the measured angular range are necessary. Several data sets measured at different concentrations and with different, completely arbitrary, primary-beam weighting functions can be considered in the same refinement. The interparticle scattering effect may also be included in the least-squares refinement. The method is general, so that different models can be tested simply by changing only one subroutine of the computer program. It may also be used to evaluate data impaired by other types of resolution errors; for example, effects due to polychromatic radiation or resolution errors in neutron scattering. Two constructed examples of the application of the method are given: (1) the calculation of the dimensions and the molecular weight of particles with a shape which can be approximated with an ellipsoid of revolution; (2) the calculation of the dimensions and electron-density distribution for spherical particles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878012807
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    The analysis of single-crystal Bragg reflections from profile measurements (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 114-120 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A method is described for finding the peak limits of a Bragg reflection from an analysis of its profile. A `window' of ± 0.67σ[φ)(x)] is set up on each ordinate φ(x) in the tails of the profile and the pattern of the following ordinates is observed through the window. As the ordinate moves from the peak to the background the pattern changes and the limits of the peak may be recognized. Bragg reflections from three crystals have been analysed by this method and the limits found were generally wider than those determined by the method of Lehmann & Larsen [Acta Cryst. (1974), A30, 580–584] applied to the same data. The value of σ(I)/I was near the minimum and similar to the value from the corrected Lehmann–Larsen limits. The behaviour of the methods is also compared by representing the reflections by equivalent Gaussian profiles, and it is found that 〉99% of the Gaussian peak is within the limits found by the present method.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878012856
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Scherrer after sixty years: A survey and some new results in the determination of crystallite size (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 102-113 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Existing knowledge about Scherrer constants is reviewed and a summary is given of the interpretation of the broadening arising from small crystallites. Early work involving the half-width as a measure of breadth has been completed and Scherrer constants of simple regular shapes have been determined for all low-angle reflections (h2 + k2 + l2 ≤ 100) for four measures of breadth. The systematic variation of Scherrer constant with hkl is discussed and a convenient representation in the form of contour maps is applied to simple shapes. The relation between the `apparent' crystallite size, as determined by X-ray methods, and the `true' size is considered for crystallites having the same shape. If they are of the same size, then the normal Scherrer constant applies, but if there is a distribution of sizes, a modified Scherrer constant must be used.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878012844
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Optimum resolution in X-ray energy-dispersive diffractometry (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 137-140 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The resolution problem in X-ray energy-dispersive diffractometry is discussed. It is shown that for a given characteristic of the solid-state detector system and a given range of interplanar spacings, an optimum scattering angle can be easily found for any divergence of the incident and scattered beams.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S002188987801290X
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Spherical monocrystals for X-ray work obtained by plasma remelting of alloy powder (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 148-150 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Spherical crystals of alloy phases too hard and brittle for grinding can be obtained by partial remelting and solidification of a powder sample. The alloy powder is blown through an argon-plasma jet melting the surface material of individual fragments, which solidify again as nearly perfect spheres. The yield is a mixture of different materials in which it is possible, however, after heat treatment to find good single crystals of the original composition. Spherical single crystals of Cu9Al4 have been produced by this method and used for a high-precision X-ray investigation described elsewhere.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878012923
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    A new computer program for contour maps of texture functions (1976)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 9 (1976), S. 254-256 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A Fortran program for plotting contour maps of texture functions is described. The program works at high speed and is very flexible in application. For input the values of the texture function, which have been measured or calculated on a grid of mesh points, are required. From these data, the single-level lines of a contour map are calculated and plotted. Format and caption of the contour map as well as the marking of the level lines can be individually chosen. In the present paper the program is applied to direct and inverse pole figures as well as to a three-dimensional orientation distribution function (ODF) of a silver sheet deformed by 99.3%.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889876011175
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Use of high and low temperature attachment for Weissenberg camera (1976)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 9 (1976), S. 258-258 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889876011205
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    Crystal data and crystal growth of PbGe3O7 (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 157-158 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Completely transparent and colourless single crystals of PbGe3O7 were grown from a melt of composition PbO.2GeO2 at 1040 K by spontaneous crystallization. The compound melts incongruently at 1070 K. The unit cell is orthorhombic with lattice constants a = 5.270 (2), b = 14.088 (4), c = 16.054 (4) Å; D293 = 5.94 (4), Dx = 5.985 g cm−3 for Z = 8. The probable space group is Pcab (D152h). A reported phase of composition PbGe205 is shown to be a mixture of PbGe3O7 and α-PbGeO3. X-ray powder data are given.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878012972
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    Crystal data for diphenyl tin sulphide trimer and n-dibutyl(ethylene-1,2-dithiol)stannane (1976)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 9 (1976), S. 507-508 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The compounds diphenyl tin sulphide trimer and n-dibutyl(ethylene-1,2-dithiol)stannane crystallize into space groups P21 and C2 respectively. The unit-cell parameters are reported.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889876012053
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    Crystal data for some o-molecular compounds (1976)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 9 (1976), S. 361-364 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Crystal data (from single-crystal measurements) are reported for 19 different crystalline π-molecular compounds, representing 16 different chemical species (three polymorphic pairs are included). 13 of these molecular compounds have equimolar compositions, five have donor:acceptor ratios of 1:2 and the remaining one has composition (fluorene)3 :( 1,3,5-trinitrobenzene)4.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889876011539
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    Alimentation autonome en azote liquide: application à un dispositif basse température Stoe (1976)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 9 (1976), S. 369-370 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889876011576
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    Präparation von biologischem Material und eine verbesserte Präparatträgerhalterung für Kiessig-Kameras (1976)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 9 (1976), S. 415-416 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889876011758
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    Symmetry Aspects of M.C.Escher's Periodic Drawings (1976)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 9 (1976), S. 417-417 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889876011801
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    Notes and News (1976)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 9 (1976), S. 417-418 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889876011813
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    A semi-automated system for identifying crystalline materials with powder diffraction data (1976)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 9 (1976), S. 419-423 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A semi-automated system has been developed for identifying the components of a crystalline mixture according to correlations between the diffraction pattern of the mixture and the Hanawalt index of the Powder Diffraction File. The system is designed for use in the laboratory with modest computing facilities, e.g. a disc or tape-based 16 K mini-computer. In the computerized stage of the system those components which cannot contribute to the measured pattern are automatically eliminated. Subsequent manual interpretation of the results of the computer search, preferably with the support of a semi-quantitative elemental analysis, further reduces the number of possibilities.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889876011849
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    On two methods of determination of particle size distribution functions by means of small-angle X-ray scattering (1976)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 9 (1976), S. 433-440 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The total X-ray intensity as a function of h (h is the radial coordinate in reciprocal space), scattered by an isotropic system of particles of equal shapes but of different sizes R, can, under certain conditions, be expressed as an integral over the particle size distribution function D(R), multiplied by a common single-particle function of hR which can be calculated from the assumed particle shape. In the first method D(R) is calculated from this relation by the method of least squares, in which values of D at a limited number of particle sizes are the unknowns. To avoid oscillations in the D curve, constraints are imposed on the D values. The proper weight to be assigned to these constraints must be determined by trial and error. The method has been adapted to suit various assumptions and requirements as to the shape of the particles, the type of distribution function to be calculated, and experimental conditions (slit or pinhole focusing). The second method is essentially the one described by Schmidt, Weil & Brill [X-ray & Electron Methods of Analysis, pp. 86–100. (1968), New York: Plenum], which, however, is adapted to the use of slit-smeared intensities. Both methods may give rise to artefacts in the calculated distribution functions in the range of the smallest particle sizes, which are sensitive to the setting of the various parameters and to experimental errors. However, the position and shape of the main maxima can usually be determined quite well. The agreement between the results obtained by the two methods is satisfactory.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889876011874
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    The absorption factor for a cylindrical specimen perpendicular to a cylindrical beam of the same radius. Application to the X-ray study of CsDNA with the use of synchrotron radiation (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 238-242 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: An X-ray diffraction study of CsDNA has been carried out with the use of synchrotron radiation of wavelength λ = 1.2 Å. The geometry corresponds to a cylindrical specimen brought into a cylindrical beam of the same diameter and the absorption factor and the primary-beam attenuation factor have been calculated as functions of specimen μR for this geometry. The optimum size of a specimen is here about 1.5 times greater than that in the case of a plane-parallel beam used in International Tables for X-ray Crystallography [Vol. II, (1967), 2nd ed., p. 295. Birmingham: Kynoch Press]. Experimental and calculated primary-beam attenuation factors have been compared and the experimental value of the linear absorption coefficient μ of CsDNA has been estimated for various humidities. The agreement between μc = 78.1 and μo = 78.2 ± 3.6 cm−1 (relative humidity 66–75%) indicates that the geometrical model used is suitable to describe polymer fibres in a cylindrical beam of nearly the same size. It is seen from the observed μ values that there is one caesium ion per nucleotide (monomer unit of DNA molecule) in the specimens used.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878013230
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 23
    Electronic Resource
    Electronic Resource
    Crystallographers (1976)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 9 (1976), S. 512-512 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889876012120
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 24
    Electronic Resource
    Electronic Resource
    Structure Reports (1976)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 9 (1976), S. 512-512 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889876012132
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 25
    Electronic Resource
    Electronic Resource
    Index of Crystallographic Supplies (1976)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 9 (1976), S. 513-513 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889876012168
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 26
    Electronic Resource
    Electronic Resource
    Crystal technology by W. L. Bond (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 293-294 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878013424
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 27
    Electronic Resource
    Electronic Resource
    Notes and News (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 293-293 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878013412
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    Electron and photn interactions with atoms edited by H. Kleinpoppen and M. R. C. McDowell (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 294-294 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878013436
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    Recent developments in polymer applications of small-angle neutron, X-ray and light scattering (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 346-375 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Recent advances in the small-angle scattering of X-rays, neutrons and light by polymers are reviewed. The three techniques are compared, from both experimental and theoretical points of view. Applications are discussed for the study of homophase and heterophase polymers, both in solution and in the solid state, as well as for unoriented and oriented crystalline polymers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878013485
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 30
    Electronic Resource
    Electronic Resource
    On the conformation of antibodies in the presence and absence of antigen (small-angle X-ray studies) (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 477-477 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The conformations of different IgG antibodies were studied before and after interaction with antigen (hapten). In every case a strong change of the conformation was observed. Binding of hapten caused a decrease of the radius of gyration by 2 to 8% and a decrease of the volume by 3 to 10%, depending on the degree of saturation with hapten. Two IgG antibodies (anti-poly-d-alanyl) were split by enzymes into fragments which contain one binding site (Fab′) and two binding sites (Fab′)2, respectively, for hapten. No changes of conformation were observed with these fragments upon the interaction with hapten. These findings lead to the conclusion that the conformation change does not take place within the area of the combining site but relatively far away, at the area of the hinge region and/or the Fc-fragment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878013631
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 31
    Electronic Resource
    Electronic Resource
    Design study of a time-of-flight small-angle diffractometer for a pulsed neutron source (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 464-465 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A design study was made of a neutron small-angle scattering (SAS) instrument for use at Argonne National Laboratory's proposed Intense Pulsed Neutron Source, IPNS-II (Carpenter & Werner, 1976; Werner, 1977; Carpenter, 1977). The instrument design incorporates several features: a converging-slit collimator, wavelength band-limiting choppers, capacity for large samples, and a two-dimensional detector. Machine design-dependent parameters are considered in a Monte-Carlo code that produces estimates of the instrumental resolution function and available flux at the sample. It was found that the calculated flux on sample exceeds that at steady-state reactor instruments of comparable resolution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S002188987801359X
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 32
    Electronic Resource
    Electronic Resource
    Large-angle X-ray diffuse scattering, a new method for investigating changes in the conformation of globular proteins in solutions (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 473-477 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A comparative analysis of the sperm-whale myoglobin structure in the crystal and in solution has been carried out with the technique previously formulated by the authors which uses the large-angle X-ray diffuse scattering for investigating the protein structure in solution. A `modified cube method', correctly taking into account the cavities within the protein molecule accessible to the solvent, is proposed for an accurate estimate of the solvent influence and for calculation of the scattering intensities. A comparison of the theoretical myoglobin scattering curves with the experimental scattering curve of this protein obtained by Stuhrmann shows rather noticeable quantitative divergences, which can be eliminated by a small increase in the distance between the `hairpin' GH and the other part of the protein molecule. It is also shown that several other physically reasonable shifts of helices (or groups of helices) do not lead to an agreement between the experimental and theoretical scattering indicatrices.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878013618
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 33
    Electronic Resource
    Electronic Resource
    Density-contrast studies of macromolecules in solution. Cross verification of X-ray scattering and pycnometry experiments (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 466-472 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The density-contrast method, commonly used in X-ray (and neutron) small-angle scattering studies of macromolecules in solution, can yield a wealth of information if; (a) the solute is monodisperse and the solution is ideal: (b) each macromolecule in solution has a volume associated with it inside of which the density distribution is independent of the density of the solvent. More specifically it has been pointed out that in this case an expression of the molecular weight can be obtained which does not involve the partial specific volume, provided that the X-ray experiments are performed on an absolute scale. On the other hand, it is well known that X-ray scattering experiments on an ideal solution of identical macromolecules can yield the molecular weight for any composition of the solvent, provided solute, solvent and partial specific volumes are defined and measured at constant chemical potential. Therefore a combination of X-ray scattering and densimetry experiments allows one to verify to what extent condition (b) holds true. Such a set of experiments has been performed on Rhesus monkey low-density serum lipoproteins, the solvent being water containing variable amounts of NaBr. It is concluded that in this case condition (b) is fulfilled. Moreover several important aspects of the analysis of the X-ray scattering curves can be verified.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878013606
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 34
    Electronic Resource
    Electronic Resource
    The measurement of the locations and radii of gyration of proteins in the 30S ribosomal subunit of E. coli by neutron scattering (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 479-482 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The theory of the technique currently in use for measuring distances between subunits in macromolecular aggregates by neutron small-angle scattering is outlined. It is shown that estimates for the radii of gyration of subunits within aggregates can be extracted from neutron distance data, in addition to the distances themselves. The current status of efforts to apply these methods to determine the structure of the E. coli ribosome is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878013643
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 35
    Electronic Resource
    Electronic Resource
    Neutron-scattering studies of chromatin subunits under a variety of contrast conditions (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 483-484 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Neutron-scattering studies of chromatin core particles in solutions containing various mixtures of D2O/H2O and small molecules (glycerol) show that the water closely associated (or bound) with the particles is largely in the outer DNA-rich regions. This confirms the fact that the particles contain a core composed of the hydrophobic regions of histone proteins.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878013655
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 36
    Electronic Resource
    Electronic Resource
    Small-angle X-ray scattering studies on polymer chain conformations in concentrated solutions and in bulk (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 514-519 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The use of the polymers tagged with heavy atoms in random positions along the chains (randomly tagged polymers) in small-angle X-ray scattering is proposed as a new method for measuring the chain conformations in concentrated solutions and in bulk polymers. The experimentally determined excess scattering from the tagged chains dispersed in the system is shown to be proportional to the scattering function of the hypothetical chains that have no tags but have the conformation of the tagged chains when the heavy atoms have sufficiently large scattering power. It has been experimentally verified that the effect of the tags on the chain conformation can be eliminated by the extrapolation of the apparent values, measured for a series of tagged polymers with various tag content, to zero tag content. The radii of gyration of the polystyrene chains (M = 1.1 × 105) in the bulk and in concentrated solutions in a good solvent and a θ-solvent have been determined. The chain dimension in a good solvent (toluene at 25°C) decreases rapidly first and then gradually approaches the unperturbed dimension with increasing polymer concentration. The dimension in a θ-solvent (trans-decalin at 21.2°C) is independent of the polymer concentration. The conformation of the polystyrene chains in the bulk was found to be a Gaussian coil.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878013771
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 37
    Electronic Resource
    Electronic Resource
    Small-angle X-ray scattering of polyethylene single-crystal suspensions (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 525-530 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Small-angle X-ray scattering from oriented mats and random suspensions of polyethylene single crystals has been studied. A modification of the Guinier equation for platelets was derived to accommodate the two-phase nature of polymer lamellae. This modification also permitted the modelling of various degrees of interaction between lamellae and suspending media. Dried crystal mats show an increase in fold period on contact with potential solvents. Crystals which have never been dried show no evidence of penetration of the fold surface by the same liquids. Apparently the drying process causes a reorganization of the surface of the lamellae. Since the fold surfaces of crystals in suspension are unaffected by the liquids used, it is reasonable to assume a `tight' fold surface model. Crystallinities calculated with this model are in excellent agreement with recent differential scanning calorimetric data on crystals kept in suspension.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878013795
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 38
    Electronic Resource
    Electronic Resource
    Organization in semi-dilute polyelectrolyte solutions observed by small-angle neutron scattering (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 519-523 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The study of semi-dilute polyelectrolyte solutions by small-angle neutron scattering shows that the correlation function S(q) of all the chains presents a peak for a value q = qh of the scattering vector q. This is taken as evidence for some organization among the elongated polyions. This phenomenon has been observed for a fraction of polymethacrylic acid of very low molecular weight. The experiments show essentially: (1) the progressive vanishing of the peak with the addition of a neutral salt at constant polyelectrolyte concentration; (2) the variation of qh with the polyelectrolyte concentration c, qh ∝ c1/2; (3) the decrease of the peak intensity as the charge density of the chain increases. These results, which indicate the important role of the electrostatic interactions on this organization phenomenon, are discussed in terms of a lattice model and a recently proposed isotropic model.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878013783
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 39
    Electronic Resource
    Electronic Resource
    Determination of the interface distribution function of lamellar two-phase systems (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 535-539 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The concept of interface distribution functions [Ruland (1977). Colloid Polym. Sci. 255, 417–427] has been applied to the evaluation of the small-angle scattering of a series of polyethylene samples. The results indicate that the statistics of the lamellar stacking is not necessarily determined by next-neighbor interactions and that non-negligible volume fractions of amorphous domains outside the lamellar systems are observed in a number of samples.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878013813
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 40
    Electronic Resource
    Electronic Resource
    A dynamic study of the crystallization of polyethylene from the melt (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 551-557 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Crystallization of a linear polyethylene from the melt was followed in situ with the ORNL 10-meter SAXS camera [Hendricks (1978). J. Appl. Cryst. 11, 15–30]. Specimens were rapidly cooled in the X-ray beam in tandem birdcage furnaces from 1̃80°C to temperatures between 115 and 126°C, and scattering patterns were recorded for 30 s in 50 s intervals. Because of this relatively high-speed data acquisition rate, it was possible to obtain data in time periods which were short compared to the rate of change of the scattering patterns. The SAXS curves showed shapes which changed continuously during crystallization. The scattering curves are the superposition of a zero-angle peak and a Bragg maximum. Guinier plots of the zero-angle peak manifest scattering by lamellae of constant thickness. The thickness value is nearly that expected for crystallites at these crystallization temperatures. A model in which skeletal spherulites form and then later fill in is consistent with these results. Decreasing SAXS intensity and changing Bragg peak intensities indicate crystal thickening during cooling to room temperature.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878013862
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 41
    Electronic Resource
    Electronic Resource
    Small-angle X-ray scattering from block copolymers as an ideal model system for a pseudo two-phase solid texture (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 558-563 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The microdomain structure of polystyrene-polyisoprene A-B type block copolymers was analysed by small-angle X-ray scattering (SAXS) as an ideal model system for a pseudo two-phase solid structure. The structure was analysed in terms of spatial distribution, size, and the interracial structure of the dispersed domains of one component (A segments) in the matrix of the other (B segments). The SAXS analyses were performed with two collimating systems, a Rigaku Denki camera (essentially a four-slit system with the addition of Soller slits) and a Kratky camera, which had widely different slit-length and slit-width weighting functions and was used to investigate instrumental effects, especially the role of the Soller slits in the obtaining of reliable desmeared intensity data in the tail of the SAXS curve. Comparison of the results indicated that the Soller slits facilitate the accurate evaluation of the interfacial thickness from the desmeared intensity data in the tail. The accuracy of the infinite slit-height approximation and the effect of truncating the higher-order terms in Ih (the intensity associated with the interphase) on the estimated interfacial thickness are discussed. The infinite slit-height approximation leads to values 25–35% smaller than the exact value (23 Å), and the truncation also leads to a value of the interfacial thickness smaller (19 Å) than the value (23 Å) based on the full analysis. The value obtained is in good agreement with the values predicted from the statistical-mechanical theories of block copolymers in bulk.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878013874
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 42
    Electronic Resource
    Electronic Resource
    Neutron small-angle scattering study of phase decomposition in Au–Pt (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 572-577 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Isothermal decomposition of a Au-60 at.% Pt alloy, quenched from the solid as well as the liquid state, has been studied with the D11 neutron small-angle scattering spectrometer at ILL, Grenoble. An incident neutron wavelength of 6.7 Å was used and measurements were carried out in the range of scattering vector [β = 4πsin θ/λ] from 2.8 × 10−2 to 21 × 10−2 Å−1. The preliminary results indicate that decomposition of this alloy at 550°C takes place by a spinodal mode, although deviations were observed from linear spinodal theory, even at very early times. Slower aging kinetics were observed in liquid-quenched alloy as compared with solid-quenched. Liquid quenching is more efficient in suppressing quench clustering than is solid quenching. However, liquid quenching yields an extremely fine-grained material, which thereby enhances discontinuous precipitation at grain boundaries, competing with decomposition in the bulk. A Rundman–Hilliard analysis was used for the early stages of the spinodal reaction to obtain an interdiffusion coefficient of the order of 10−16 cm2 s−1 at 550°C for the solid-quenched alloy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878013904
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 43
    Electronic Resource
    Electronic Resource
    Small-angle electron scattering in the transmission electron microscope (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 564-568 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Two methods for performing small-angle electron scattering (SAES) experiments in transmission electron microscopes are described: the long-camera-length method and the selected-area-diffraction method. It is shown experimentally that angular resolutions of a few microradians and a few tenths of milliradians, respectively, are easily obtained by these two methods. A number of examples of the application of SAES to problems in materials science are presented. The use of new high-brightness electron sources is expected to produce significant increases in angular resolution, and the use of electron-energy analyzers will permit the separation of most of the inelastic contribution to the SAES intensity distribution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878013886
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 44
    Electronic Resource
    Electronic Resource
    A small-angle neutron scattering study of the temperature and stress dependence of the microstructure of nimonic alloys (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 583-588 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The creep properties in high-temperature alloys are dependent on the presence of second and higher phase components. In particular in the nimonic group of alloys the size distribution and concentration of the γ′ phase are crucial factors in the resistance to creep. A possible mechanism for degradation of creep resistance is the Ostwald ripening of the γ′ phase. A sample of Nimonic 105 (Trademark of Henry Wiggin and Co. Ltd) was subjected simultaneously to a stress of 500 MPa and a temperature of 800°C in situ in the beam using a specially developed cell on the small-angle scattering facility (D 11A) at the Institut Laue Langevin. Scattering patterns were taken continuously and spectra were recorded every ̃20 min; the macroscopic creep was also recorded. Measurements were taken up to the point of fracture. A peak in the intensity was observed at a scattering vector κ (= 4π sin θ/λ) of 0.005 Å−1 which is believed to be the lowest value at which such an effect has been observed in alloys. The observed variation in the scattering after treatment for multiple scattering and absorption corrections is discussed in terms of particle size and size distribution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878013941
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 45
    Electronic Resource
    Electronic Resource
    A modified mirror monochromator for rotation photography of large-unit-cell crystals (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 658-661 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A double-mirror monochromator in which one of the mirrors is considerably longer than conventionally employed has been used to collect diffraction data from crystalline tobacco mosaic virus (TMV) protein (unit cell: 224 × 228 × 174 Å). Considerable improvements in speed of data collection are observed over both customary focusing optics and pinhole collimation. Quantitative comparisons are made of the quality of data collected from TMV protein by this method and by the use of nickel-filtered radiation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878014168
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 46
    Electronic Resource
    Electronic Resource
    Anisotropy in the flux-line lattice symmetry of a low-κ Type II superconductor (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 654-657 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Correlation between the symmetry of the two-dimensional flux-line lattice (FLL) and the real crystal lattice (CL) has been studied in a superconducting niobium sphere by means of small-angle neutron diffraction. A double-perfect-silicon-crystal diffractometer enabled precise determination of the three interfluxoid distances corresponding to the FLL basic cell. A systematic study of the anisotropic behavior was made as a function of temperature and magnetic field amplitude for fields parallel to a few high-symmetry CL axes in the (1{\bar 1}0) plane. In addition, at T = 4.30 K progressive deformation of the FLL was studied as the sample was rotated in the (1{\bar 1}0) and (100) planes. The FLL was found to be hexagonal only for fields parallel to the threefold CL axis. Twofold symmetry prevailed for other CL directions in these planes except near the fourfold axis, where either of two distorted triangular lattices existed, preserving the reflection symmetry in composite, but not individually. When compared to current models for fluxoid-CL interactions, the present results show that no theory predicts the observed behavior quantitatively under general conditions, but some models agree well for certain high-symmetry CL axes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878014156
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 47
    Electronic Resource
    Electronic Resource
    An error in several published tables of the multiplicities of powder reflexions (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 669-669 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Some multiplicities for the Laue class \bar 31m are not correct in several standard texts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878014181
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 48
    Electronic Resource
    Electronic Resource
    Determination of low-field critical parameters of superconducting niobium by small-angle neutron diffraction (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 650-653 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The double-perfect-crystal small-angle diffraction technique enables measurement of scattering angles to within an accuracy of 0.3′′ of arc. At a wavelength of 2.55 Å, this provides a resolution of 3 × 10−6 Å−1 in the scattering vector. This technique has been used to study the anisotropic behavior of the critical parameters B0 and Hc1, characteristic of the first-order magnetic phase transition which occurs in low-κ type II superconductors. Magnetic fields were applied parallel to several crystal axes in the (1{\bar 1}0) and (100) planes of a large single-crystal sphere of pure niobium, resulting in well defined flux-line lattices (FLL). Measurement of the FLL cell area in the intermediate, mixed-state-field region gives the equilibrium flux density B0, which results from an attractive interaction between fluxoids. In addition, field variation of the scattered neutron intensity allows measurement of the transition field between the mixed state and intermediate mixed state. This transition field is related to the lower critical field Hc1 and enables its determination to a precision of 0.2%. Data at T = 4.3 K display a small anisotropic effect of about 2% in B0 and 1% in Hc1. Although orientation effects of this magnitude are difficult to resolve by bulk measurements, the neutron data are in accord with magnetization data. The temperature dependence of these parameters is found to be in qualitative but not quantitative agreement with current theoretical models.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878014144
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 49
    Electronic Resource
    Electronic Resource
    A computer program for determining multiplicities of powder reflections: a correction (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 669-669 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: An amendment to a computer program for determining multiplicities of powder reflections [Rouse & Cooper (1977). J. Appl. Cryst. 10, 134–135] has been made to correct an error in the multiplicity values given for some reflections for space groups with {\bar 3}1m Laue symmetry, which exists in some of the standard texts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878014193
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 50
    Electronic Resource
    Electronic Resource
    Precision lattice parameter measurement by the X-ray divergent-beam technique (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 662-668 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A method is described for precision measurement of lattice parameters in cubic crystals, interplanar spacings and angles between crystallographic directions for single crystals of any system. The minimum measurable values of angle between crystallographic directions, Δd/d and Δa/a have been found to be ̃105 rad, ̃3 × 10−5, and ̃5 × 10−5, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S002188987801417X
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 51
    Electronic Resource
    Electronic Resource
    Observation of lead Lα radiation from commercial X-ray tubes (1976)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 9 (1976), S. 370-370 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889876011588
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 52
    Electronic Resource
    Electronic Resource
    World Directory of Crystallographers. Fifth Edition (1976)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 9 (1976), S. 371-371 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889876012272
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 53
    Electronic Resource
    Electronic Resource
    Crystal data for diphenylsilanediol, (C6H3)2Si(OH)2 (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 670-671 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The cell constants of recrystallized diphenylsilanediol were refined from precision powder data taken with Cr Kα1 (2.28962 Å): a = 14.493 (5); b = 15.012 (6); c = 9.897 (6) Å; α = 100.84 (9); β = 100.01 (5); γ = 120.77 (5); U = 1721.6 Å3; Z = 6; Dm (25°C) = 1.255 (3); Dx = 1.252 g cm−3.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S002188987801420X
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 54
    Electronic Resource
    Electronic Resource
    Lattice parameter measurements in epitaxic layers (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 671-671 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878014211
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 55
    Electronic Resource
    Electronic Resource
    Crystal growth and materials edited by E. Kaldis and H. J. Scheel (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 673-674 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878014247
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 56
    Electronic Resource
    Electronic Resource
    Simulation of photographs on a storage display. Application to X-ray topography and TEM (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 675-680 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The simulation of the photography remains the worst part in the calculation of transmission electron micrographs and X-ray topographs. Storage displays have been used to enhance this part of the process and the different possibilities of these screens studied. The quality of all simulations has been substantially increased by using these displays, which are now in common use.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878014259
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 57
    Electronic Resource
    Electronic Resource
    High-resolution energy-dispersive diffraction using synchrotron radiation (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 684-687 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A high-resolution energy-dispersive diffractometer is described, which uses a synchrotron source and a scanning channel-cut silicon crystal. The technique is demonstrated with a powdered sample of BaTiO3 and analysis of the profiles demonstrates the anomalous particle-size effect reported by Anliker, Brugger & Känzig [Helv. Phys. Acta (1954), 27, 99–124].
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878014272
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 58
    Electronic Resource
    Electronic Resource
    Crystal mounter (1976)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 9 (1976), S. 416-416 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S002188987601176X
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 59
    Electronic Resource
    Electronic Resource
    International Tables for X-ray Crystallography (1976)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 9 (1976), S. 417-417 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889876011795
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 60
    Electronic Resource
    Electronic Resource
    Practical electron microscopy in materials science edited by J. W. Edington (1976)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 9 (1976), S. 418-418 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889876011825
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 61
    Electronic Resource
    Electronic Resource
    Applications of liquid crystals by G. Meier, E. Sackamann and J. G. Grabmaier (1976)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 9 (1976), S. 418-418 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889876011837
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 62
    Electronic Resource
    Electronic Resource
    Estimating unit cell volumes from powder diffraction data: the triclinic case (1976)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 9 (1976), S. 424-428 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: In the computer indexing of powder diffraction patterns, an advance estimate of the volume of the unit cell is extremely valuable. This paper describes a method for estimating it directly from powder-pattern data for the case of triclinic materials. The method involves an easily prepared graphical plot, the slope of which is proportional to the unit-cell volume. First, the diffraction lines are numbered consecutively, starting with the largest d value (N = 1). A plot is then made of 1/N versus d3. Theoretically, the resulting line has a slope of 3/(2πV) = 0.4775/V for triclinic compounds, where V is the unit-cell volume. Examination of the graphs plotted for a number of triclinic materials where the experimental data are of high quality shows that the slope consistently falls around 0.60/V. Hence, the volume of the unit cell and/or the calculated density can be estimated. In addition, this analysis gives a numerical measure of the fraction of possible diffraction lines actually observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889876011850
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 63
    Electronic Resource
    Electronic Resource
    A computer-controlled triple-axis neutron spectrometer with CAMAC interface (1976)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 9 (1976), S. 444-453 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A description is given of the computer-controlled triple-axis neutron spectrometer system installed at the PLUTO reactor at Harwell. Following the operation of the original system for several years a number of major improvements have been made which have resulted in a highly reliable system which provides the users with very powerful and extensive facilities. Following a general description of the modified spectrometer, details are given of the new computerized control system which utilizes a CAMAC modular interface and the functions of the various programs which are now available to the users are described.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889876011904
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 64
    Electronic Resource
    Electronic Resource
    Diffraction from materials edited by L. H. Schwartz and J. B. Cohen (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 719-720 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878014466
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 65
    Electronic Resource
    Electronic Resource
    Crystal growth 1977 edited by R. L. Parker, A. A. Chernov, G. W. Cullen and J. B. Mullin (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 720-720 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878014478
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 66
    Electronic Resource
    Electronic Resource
    Eigenvalue filtering in the refinement of crystal and orientation parameters for oscillation photography (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 238-243 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Selective application of only parameter shifts with large eigenvalues permits singular or near-singular least-squares problems to be solved. This `eigenvalue filtering' process has been applied to the refinement of the unit-cell, crystal-orientation and reflecting-range parameters needed to process oscillation films. Eigenvalue filtering permits automatic identification and determination of just those combinations of parameters that are most relevant for processing films from a particular crystal in a particular setting. The procedure may be carried out with alignment information from an individual data film or from multiple alignment films taken at different spindle angles. Eigenvalue filtering has been incorporated in a refinement program that minimizes discrepancies between observed and calculated fractions recorded for partially recorded reflections. This permits the reflecting range (combined mosaic spread, beam cross-fire, and wavelength spread) to be refined along with the unit-cell and orientation parameters. Observed fractions recorded may be obtained by visual estimation prior to film scanning, or the program may be used in a `post-refinement' mode with data obtained from actual intensity measurements. The relatively unreliable information represented by the positions of spots on the film is not used except for indexing. The program handles crystals of any symmetry in any setting and the oscillation spindle may be inclined from normal beam geometry. The mis-setting angles are defined in a crystal-fixed coordinate system, making it easy to compare refinement results for data taken at different spindle angles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889884011444
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 67
    Electronic Resource
    Electronic Resource
    Optimization of the experimental resolution for small-angle scattering (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 249-256 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The instrumental optimization conditions for most small-angle scattering experiments in which the data are azimuthally symmetric require that the scattered flight path be equal to the incident flight path. This is in contrast to a recent analysis which shows that under some conditions the incident and scattered flight paths are in a ratio of two to one. The equal flight-path condition is also valid for experiments measuring sharp (Bragg-like) peaks, or where the intensity is required at specific scattering vectors, as in low-angle diffraction of ordered or semiordered systems. The implications of the optimization conditions on the resolution and count rates at the detector are discussed for both types of experiment, and the dependence of the resolution on the spectrometer geometry is considered.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889884011468
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 68
    Electronic Resource
    Electronic Resource
    High-resolution measurements of angle-resolved X-ray scattering from optically flat mirrors (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 257-264 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: With a compact arrangement using single-crystal collimator and analyzer (silicon 220 reflection) of channel-cut type, angle-resolved scattering (ARS) curves of X-rays (Cu Kα1) for optically flat mirrors have been measured at various glancing angles, ω, of X-rays to the mirror surface with an angular resolution of 4′′. Weak scattered intensity (10−3–10−5 of the specularly reflected beam) is observed over an angular range of a few hundred arc s below and above the direction of specular reflection. When ω is close to the critical angle for total reflection, the scattered intensity at the low-angle tail of ARS curves is higher than that at the high-angle tail. This asymmetric tail profile of ARS curves is explained by simply superposing intensities of specularly reflected beams from surface elements inclined to each other.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S002188988401147X
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 69
    Electronic Resource
    Electronic Resource
    Comments on Small-angle scattering at a pulsed neutron source: comparison with a steady-state reactor (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 293-294 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A recent comparison of data for a specific experiment taken on a time-of-flight small-angle scattering spectrometer on a pulsed neutron source and data for the same kind of experiment taken at a steady-state reactor suggests that the instruments have similar performances, and in particular comparable count rates at the detector. This similarity disappears when resolution is taken into account. The criterion for a valid comparison should be the detector count rate for instruments measuring over similar ranges of scattering vector and with similar resolutions, as required by the particular experiment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889884011523
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 70
    Electronic Resource
    Electronic Resource
    Accuracy and resolution in protein crystallography: a probabilistic approach (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 273-285 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The purpose of this paper is to establish an explicit correlation between the values and probable deviations of the observed intensities and the potential accuracy of the structure eventually determined using those intensities. This problem involves several steps: the choice in real space of a reference stochastic model defining the ideal state of ignorance; the determination in reciprocal space of the probability density corresponding to that model and of the probability law corresponding to the experiment; the determination of the information; the transfer of the information from reciprocal to real space; the interpretation of the information in terms of structural resolution. A rigorous treatment of this problem is hindered by the inadequate knowledge of the statistical correlations between different reflections; more realistically, it is convenient to address a simpler problem, corresponding to an ideal experiment in which the intensities relevant to each reflection are measured independently of all the other reflections. In this case the mathematical problems can easily be solved and a parameter introduced – called projection information – whose value can be determined. This information is the sum of two terms, one associated with the modulus, the other with the phase of each reflection. By resorting to a mathematical model it is possible to make use of the projection information to determine the value of a parameter akin to structure resolution. The final result of this work is an operational definition of resolution, based upon the stochastic properties of the experimental observations. This resolution can be used to assess and compare the intrinsic quality of different structure analyses and of different stages of one structure determination, before the structure is solved.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S002188988401150X
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 71
    Electronic Resource
    Electronic Resource
    The effect of profile-step counting time on the determination of crystal structure parameters by X-ray Rietveld analysis (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 297-306 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Crystal structure parameters have been obtained for α-Al2O3, β-PbO2 and (Mg, Fe)2SiO4 by Rietveld analysis of Cu Kα X-ray powder diffraction data collected on a conventional diffractometer using counting times ranging from 0.01 to 5 s per step. For all but the 0.01 s data collected on (Mg, Fe)2SiO4 the structural parameters obtained at different counting times are statistically identical at the 3 σ level, and the spread in the values is essentially the same as that obtained by sample repacking at a fixed counting time of 1 s per step. The parameter e.s.d.'s and conventional agreement indices Rwp and RB decrease to values limited by residual model errors as the counting time increases, but the goodness-of-fit parameter becomes unacceptably larger than its ideal value of unity. When more than a few thousand counts are accumulated for the maximum step intensity in the diffraction profile a weighting scheme based solely on counting variance is inappropriate and the parameter e.s.d.'s are no longer a reflection of their accuracy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889884011547
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 72
    Electronic Resource
    Electronic Resource
    The many-beam moiré effect in electron micrographs of epitaxic Sn/SnTe layers (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 307-314 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The many-beam dynamical theory of moiré fringes of Gevers [Phys. Status Solidi (1963). 3, 2289–2297] has been applied to the parallel moiré case and the results have been verified on epitaxically grown Sn/SnTe specimens showing the sensitivity of moiré patterns to the presence of systematic reflections. The Fourier analysis of the calculated intensity profiles showed that each additional diffracted beam gives rise to a new term in the Fourier series so that the profile can be sinusoidal only in the two-beam approximation. The same result has been obtained recently by Pardo, Pariset & Renard [Phys. Status Solidi A. (1981). 64, 283–295], who applied a slightly different theoretical approach to Sb/Bi specimens. It is shown that the corrections to scattering factors for temperature effects are not important since they do not affect the general character of the moiré profiles. Some experiments were performed showing the dependence of the moiré pattern on the number of beams that are transmitted through the objective aperture. The effect of the gradual thinning of one layer on the moiré pattern could be reproduced by computer simulation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889884011559
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 73
    Electronic Resource
    Electronic Resource
    The true unit cell of ammonium hydrogen sulfate, (NH4)3H(SO4)2 (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 331-333 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A combination of X-ray powder diffraction and single-crystal Laue photography was used to determine the unit-cell parameters for letovicite. μr = 247.25. The unit cell is triclinic, P1 or P{\bar 1}, and has dimensions a0 = 5.87(1), b0 = 10.17(3), c0 = 8.27(1) Å, α = 101.1(4), β = 111.1(1), γ = 89.9(2)°, V = 450.7 Å3, Z = 2, Dx = 1.82 Mg m−3. The M(20) cell reliability is 23.8. Many weak powder spectra were observed, which preclude the possibility of monoclinic cell symmetry previously reported. Projection of the letovicite Laue data along [001] reveals the striking pseudo-hexagonal symmetry observed optically. The JCPDS Diffraction File No. for ammonium hydrogen sulfate is 35-1500.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889884011596
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 74
    Electronic Resource
    Electronic Resource
    On the automatic extension of incomplete models by iterative Fourier calculation (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 364-366 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A program is presented that solves crystal structures completely using advanced Fourier methods starting from a small known fraction (about 8%) of the structure. The program uses a statistical test based on the R2 factor to check the correctness of the model obtained so far. The results obtained with four test structures are given.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889884011705
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 75
    Electronic Resource
    Electronic Resource
    A sample holder for cutting single crystals along any desired X-ray oriented plane (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 369-370 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889884011730
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 76
    Electronic Resource
    Electronic Resource
    Use of a one-dimensional position-sensitive detector with a Kratky camera (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 370-370 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889884011742
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 77
    Electronic Resource
    Electronic Resource
    A technique for the preparation of low-temperature powder samples of noxious materials (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 372-372 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889884011766
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 78
    Electronic Resource
    Electronic Resource
    Crystallographers (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 373-373 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S002188988401178X
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 79
    Electronic Resource
    Electronic Resource
    Single-peak methods for Fourier analysis of peak shapes (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 22-26 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Several procedures for Fourier analysis of single diffraction peaks for microstrains and mosaic sizes are compared. A simple new method works well, especially when the size distribution is broad, and/or when the strains vary in an unusual manner.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889884010943
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 80
    Electronic Resource
    Electronic Resource
    A computer program for unique indexing of electron diffraction patterns (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 39-42 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A computer program for unambiguous and consistent indexing of a series of single-crystal diffraction patterns is discussed which allows determination of the unit triangle and therefore tilting of the specimen into any special orientation even if no Kikuchi patterns can be observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889884010980
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 81
    Electronic Resource
    Electronic Resource
    The peak in neutron powder diffraction (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 47-54 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: For the application of Rietveld profile analysis to neutron powder diffraction data a precise knowledge of the peak profile, in both shape and position, is required. The method now in use employs a Gaussian-shaped profile with a semi-empirical asymmetry correction for low-angle peaks. The integrated intensity is taken to be proportional to the classical Lorentz factor calculated for the X-ray case. In this paper an exact expression is given for the peak profile based upon the geometrical dimensions of the diffractometer. It is shown that the asymmetry of observed peaks is well reproduced by this expression. The angular displacement of the experimental profile with respect to the nominal Bragg angle value is larger than expected. Values for the correction to the classical Lorentz factor for the integrated intensity are given. The exact peak profile expression has been incorporated into a Rietveld profile analysis refinement program.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889884011006
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 82
    Electronic Resource
    Electronic Resource
    Scaling and phase-difference determination in solvent contrast variation experiments (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 77-84 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: In the solvent contrast variation technique, the structure factor is a linear function of contrast, and the intensity is therefore a parabolic function of contrast. A method has been developed which scales together data measured at different contrasts on different samples. Once the data are scaled, structure-factor amplitudes or intensities for any other contrast can be obtained by inter- (or extra-)polation. The magnitude of the relative phase change between contrast, an important piece of phasing information in single-crystal studies, can be determined.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889884011031
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 83
    Electronic Resource
    Electronic Resource
    X-ray study on the successive phase transition in cholesteryl 2,2,3,3-tetrafluoropionate (CTFP) (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 100-102 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: These studies on phase transition and crystal structure in a single-crystal of CTFP by X-ray diffraction in the temperature range 88 to 293 K show that CTFP undergoes successive phase transitions at about 123, 143 and 178 K and that the existence of another phase transition at about 168 K is possible. In the lowest-temperature phase, various commensurate and incommensurate structures were found. The appearance of the structure depends on storage duration at 293 K after undergoing the successive phase transitions. The original crystal, just crystallized from acetone solution, showed commensurate structure of which the modulation wave number, δ, is 0.20. The samples stored for a week and a month were both incommensurate. However, the crystals stored for two months were commensurate (δ = 0.20). Therefore, the storage duration of two months is a relaxation time long enough to recover the genuine structure. In the other temperature phases below 178 K, the crystals were all incommensurate. Consequently, the complicated structural change of CTFP crystals during storage is now well understood as a thermal relaxation phenomenon.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889884011067
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 84
    Electronic Resource
    Electronic Resource
    A device for the easy centering of a Gandolfi X-ray diffraction camera (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 120-121 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889884011110
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 85
    Electronic Resource
    Electronic Resource
    Appreciation of Co-editor's Service (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 122-122 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889884011146
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 86
    Electronic Resource
    Electronic Resource
    Comparaison de precédures d'evaluation des distortions et de la taille des cristallites par analyse des raies de diffraction des rayons X (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 131-133 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A procedure based on successive convolution operations is developed and associated with the Warren–Averbach method. Applications to cold-worked lithium fluoride samples are presented. The microstrain results are compared with those obtained in the classical way including the use of the direct deconvolution method. It is shown experimentally that the difficulties involved in the deconvolution operation have no significant effect on the evaluation of microstrains by the classical X-ray line-profile analysis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889884011183
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 87
    Electronic Resource
    Electronic Resource
    Intensity of secondary scattering of X-rays by non-crystalline materials. Transmission gemoetry with an incident-beam monochromator (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 134-139 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Equations are derived for the intensity ratio R of secondary to primary scattering in the fixed-sample transmission case with an incident-beam monochromator crystal that results in a polarization ratio Km for unpolarized incident radiation. A table allows R to be calculated for Km = 0. This table, along with the one for Km = 1 published previously for the case without a monochromator, allows R to be estimated before an experiment is done and thus an optimum experiment can be designed. A simple computer program allows direct calculation of R once experimental data are obtained if it is desired to avoid interpolation. Determination of R involves some approximation, but the values obtained are sufficiently accurate for most purposes. However, R can be improved using exact equations, if desired. If synchrotron radiation polarized normal to the plane of scattering of the monochromator is used, R does not depend on Km, and the value of R for Km = 0 applies despite the true value of Km. As is expected from symmetry considerations, R is independent of Km in the small-angle scattering limit.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889884011195
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 88
    Electronic Resource
    Electronic Resource
    A new linear position-sensitive scintillation detector for neutron powder diffractometry (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 159-166 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A new linear position-sensitive scintillation detector has been developed and installed on a neutron powder diffractometer. The physical properties of this detector are described; test powder diffractograms are presented. The special advantages of this detector for neutron powder diffractometry are discussed: high detection efficiency also in the region of short wavelengths (75% for λ = 1.3 Å), good spatial resolution (FWHM = 2.5 mm), and high data-point density (Δ2θ = 0.02°). Special emphasis is placed on peak-profile analysis for the powder diffraction patterns. Examples for position and intensity separation of overlapping reflections are presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889884011237
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 89
    Electronic Resource
    Electronic Resource
    The formation of double-polytype regions in ZnS crystals (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 167-171 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A 3 mm long double-polytype region was found in a ZnS needle. The region consists of a fine mixture of 47% of each of the polytypes 20L(5753) and 60R(5537)3 and about 6% of the polytype 60R(511553)3. The latter polytype is assumed to be the parent polytype transforming into the two others. It is the first time that traces of the parent polytype have been found in a double-polytype region. The formation mechanism of double-polytype regions is explained as a two-stage transformation process: expansion of grown-in stacking faults taking place at temperatures just below the hexagonal-to-cubic transition temperature, followed by a sudden formation and expansion of stacking faults at a lower temperature. It is suggested that a similar mechanism operates in the formation of single polytype regions and disordered ones.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889884011249
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 90
    Electronic Resource
    Electronic Resource
    A proposal for a highly efficient double-crystal monochromator for thermal neutrons (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 189-195 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The optimum parameters and properties of a new type of neutron monochromator based on elastically bent silicon single crystals are theoretically evaluated. The use of a fully asymmetrical geometry permits the achievement of rocking-curve widths exceeding 20' in the incident beam. The associated effect of the reflected-beam widening is compensated for by the second crystal in the parallel (1,−1) setting in opposite geometry. Reflectivity calculations indicate that this double-crystal system might be compared with the best single-crystal mosaic monochromators. Besides the easy control of the effective mosaicity and the corresponding integrated reflectivity by variation of the bending radius, a further advantage of this system is its simultaneous action as a neutron filter improving the ratio of the thermal neutron signal to the background.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889884011274
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 91
    Electronic Resource
    Electronic Resource
    The reduction of radiation damage in protein crystals by polyethylene glycol (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 209-210 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A simple technique has been developed to lessen radiation damage of protein crystals grown from low-ionic strength solution. The technique consists of replacing the mother liquor with solutions containing 10–20% of polyethylene glycol 4000 or 20000.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889884011316
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 92
    Electronic Resource
    Electronic Resource
    Crystal data for p-dichlorobenzene, p-dibromobenzene and their mixed crystals at 293 K (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 210-211 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The powder data at 293 K of p-dichlorobenzene (pDCB), C6H4Cl2, p-dibromobenzene (pDBB), C6H4Br2, and of their mixed crystals [pDCB]x [pDBB](1−x) are reported. Their thermal stability at 293 K is given. They are all isomorphous, monoclinic, P21/a with Z = 2. a = 14.792 (6), b = 5.839 (2), c = 4.036 (2) Å, β = 112.52 (4)°, V = 322.0 (5) Å3, Dx = 1.516 Mg m−3 for pDCB; a = 15.487 (2), b = 5.836 (2), c = 4.108 (1) Å, β = 112.74 (1), V = 342.5 (3) Å3, Dx = 2.289 Mg m−3 for pDBB; a = 14.893 (10), b = 5.837 (7), c = 4.046 (3) Å, β = 112.48 (5)°, V = 325.1 (9) Å3, Dx = 1.592 Mg m−3 for [pDCB]0.90[pDBB]0.10; a = 14.942 (5), b = 5.840 (2), c = 4.048 (1) Å, β = 112.53 (3)°, V = 326.3 (4) Å3, Dx = 1.677 Mg m−3 for [pDCB]0.80 [pDBB]0.20; a = 15.018 (4), b = 5.846 (1), c = 4.061 (1) Å, β = 112.50 (2)°, V = 329.4 (3) Å3, Dx = 1.751 Mg m−3 for [pDCB]0.70 [pDBB]0.30; a = 15.138 (11), b = 5.843 (3), c = 4.067 (3) Å3, β = 112.57 (8)°, V = 332.2 (8) Å3, Dx = 1.825 Mg m−3 for [pDCB]0.60 [pDBB]0.40; a = 15.247 (6), b = 5.842 (2), c = 4.081 (2) Å, β = 112.66 (5)°, V = 335.4 (5) Å3, Dx = 1.896 Mg m−3 for [pDCB]0.50 [pDBB]0.50; a = 15.300 (5), b = 5.838 (1), c = 4.081 (1) Å, β = 112.54 (4)°, V = 336.7 (3) Å3, Dx = 1.976 Mg m−3 for [pDCB]0.40 [pDBB]0.60; a = 15.373 (4), b = 5.842 (1), c = 4.094 (1) Å, β = 112.64 (3), V = 339.3 (3) Å3, Dx = 2.048 Mg m−3 for [pDCB]0.30 [pDBB]0.70; a = 15.410 (7), b = 5.838 (4), c = 4.098 (2) Å, β = 112.65 (3)°, V = 340.2 (6) Å3, Dx = 2.129 Mg m−3 for [pDCB]0.20 [pDBB]0.80; and a = 15.450 (3), b = 5.838 (1), c = 4.103 (1) Å, β = 112.69 (1)°, V = 341.4 (2) Å3, Dx = 2.208 Mg m−3 for [pDCB]0.10 [pDBB]0.90. The JCPDS Diffraction File Nos. are: 34-1987 for pDCB; 34-1985 for pDBB; 34-1986 for [pDCB]0.50 [pDBB]0.50.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889884011328
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 93
    Electronic Resource
    Electronic Resource
    A procedure for search/match analysis of X-ray powder diffraction patterns using compact data bases (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 212-214 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A microcomputer-based method has been developed for rapid search/match analysis of X-ray diffraction patterns from compound mixtures with user-assembled data bases for specific sample types, e.g. air pollutants, asbestiform minerals, mineral sands and coal ash. Accidental coincidences between stored and measured patterns are largely eliminated using status parameters which are assigned to each data base and measured line. Scaling factors determined for each of the identified compounds afford calculation of relative concentration values. The list of unassigned lines is presented for subsequent analysis with other compact data bases or using more complex search/match methods.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889884011353
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 94
    Electronic Resource
    Electronic Resource
    Crystallographers (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 217-218 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889884011390
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 95
    Electronic Resource
    Electronic Resource
    Use of synchrotron radiation sources for X-ray diffraction topography of polytypic structures (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 231-237 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The potential of synchrotron radiation sources (SRS) for the topography of polytypic structures has been assessed. Thus it has been found that the white radiation and low divergence characteristics of the SRS are uniquely suitable for accommodating the complications of mixed polytypes, heavily distorted crystals and edge-reflection topography. Computer aids are particularly important for separating contributions from mixed polytype crystals. All these techniques are illustrated in this paper using silicon carbide as a prototype polytypic crystal.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889884011432
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 96
    Electronic Resource
    Electronic Resource
    OMITMAP: An electron density map suitable for the examination of errors in a macromolecular model (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 244-248 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A single-stage computer procedure to calculate an electron density map suitable to detect errors in a tentative macromolecular model has been developed. In this procedure, an atom of the tentative model does not contribute to the phases used to calculate electron density values at or near its current position, that is within the region containing it and a neighborhood surrounding that region. In this way, the phases used to calculate electron density values within a region are not biased by the model atoms contained within that region or its neighborhood. The number of atoms which are omitted for a given region is maintained at a small fraction of the total structure so that the phases used to calculate electron density values may still be a good approximation to the phases of the complete structure. The procedure was used to improve the model of the Fab portion of the mouse galactan-binding immunoglobulin J539 (IgA2, κ), which contains 431 residues.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889884011456
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 97
    Electronic Resource
    Electronic Resource
    A Voigtian as profile shape function in Rietveld refinement (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 352-357 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A modification of the Rietveld refinement program is introduced by replacing the Gaussian profile function with a Voigtian. The performance of the program is tested by an application to simulated and measured diffraction patterns of NaTaO3, and excellent results are obtained when the tails of the reflections are included at distances 10 to 20 times the half-width of the reflections. Comparison between Gaussian and Voigtian refinements show large differences in the thermal parameters. This is due to the high level of background that is assumed in the Gaussian refinement to compensate for the lack of tail overlap. Application of the Voigtian refinement to the measured pattern of Ni yields a thermal parameter that is close to the literature values, while the Gaussian analysis gives a value which is 35% too large. The isotropic temperature factors of the room-temperature structure of NaTaO3, respectively, drop down to the values B(Ta) = 0.09(2), B(Na) = 1.21(3), B(O1) = 0.59(3) and B(O2) = 0.61(3) Å2, when the Voigtian analysis with a proper background is carried out. The role of background in powder pattern refinement is discussed, and it is suggested that a calculation of the average TDS should be included in the refinement.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889884011638
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 98
    Electronic Resource
    Electronic Resource
    A segment description for the unique set of reflections in non-centrosymmetric crystal classes (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 361-362 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The segment description of the unique set of reflections of Gabe [In Crystallographic Computing, edited by F.R. Ahmed. Copenhagen: Munksgaard (1969)] and Le Page & Gabe [J. Appl. Cryst. (1979). 12, 464–466] has been extended to the non-centrosymmetric crystal classes. To the reflections generated by the unique set of the Laue group are added the anti-reflections generated by a set of anti-segments. These anti-segments are defined by the same lattice rows as those of the corresponding Laue group but their origins are shifted to avoid generating anti-reflections in any centrosymmetric section of reciprocal space.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889884011663
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 99
    Electronic Resource
    Electronic Resource
    Some aspects of the X-ray structural characterization of (Ga1−xAlxAs)n1(GaAs)n2/GaAs(001) superlattices: erratum (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 362-362 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: In the paper by Kervarec, Baudet, Caulet, Auvrey, Emery & Regreny [J. Appl. Cryst. (1984). 17, 196–205], an error has been introduced. On page 202, right-hand column, the second paragraph should read: The uneven surfaces of the interfaces can be taken into account by assuming that the SL is made of a juxtaposition of perfect crystallites of the same composition x whose period varies between the extreme values of 2n1d1 + 2n2d2. In this hypothesis, the experimental diagram is the sum of the X-ray diagrams given by each crystallite; the value of n1 + n2 deduced from such a diagram is an average value in the sample zone analyzed, therefore most of the time not integer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889884011675
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 100
    Electronic Resource
    Electronic Resource
    An enhanced interactive PLUTO78 for molecular display (1984)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 17 (1984), S. 366-368 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The well known molecular drawing program, PLUTO78, has been made more widely available in the UK by mounting it on the minicomputers of the Joint Academic Network (JANET) wide-area network. Enhancements include interaction, faster plotting, use of colour and simulated half tone, easy access to centrally maintained high-quality-output devices, and the provision of comprehensive documentation in the form of on-line help and a user manual.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889884011717
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...