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
  • International Union of Crystallography (IUCr)  (1,489)
  • 1975-1979  (1,489)
  • 1978  (1,489)
  • 1
    Electronic Resource
    Electronic Resource
    The analysis of X-ray diffraction profiles from imperfect solids by an application of convolution relations (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 6-9 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: In this investigation an attempt has been made to correlate the experimentally observed X-ray diffraction profile from imperfect solids with the one obtained theoretically from an approach of simultaneous convolution of the true diffraction profile resulting from the imperfection content of the materials and the instrumental profile, considering realistic distribution functions. The expressions for the intensity distributions are derived from the simultaneous convolution of Schoening's true profile (originating from the Gaussian strain profile and the Cauchy crystallite-size profile) and the instrumental profile having either Gaussian or Cauchy functional forms, and the theoretical forms are compared to those observed from some silver- and copper-base cold-worked alloys and vapour-deposited thin silver films. The agreement is fairly good for both first- and second-order reflections with small deviations in the tail region, which may arise from uncertainty in the background-level estimation, consideration of functions purely symmetrical in form and neglect of absorption and TDS effects. A further agreement of Schoening's true profile with Stokes's corrected deconvoluted true profile implies the validity of Schoening's approximation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878012595
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Crystal data for 15-O-acetylacerinol and two related triterpenes isolated from Japanese Cimicifuga plants (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 58-58 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Three triterpenes, 15-O-acetylacerinol, simplexyl acetate and O-methylcimiacerol have been obtained from Cimicifuga plants and recrystallized from ethyl acetate. 16-O-Acetylacerinol is tetragonal, space group P43212 or P41212, a = b = 7.7624 (7), c = 98.601 (8) Å, V = 5941.2 Å3; simplexyl acetate is monoclinic, space group P21 or P21/m, a = 15.513 (2), b = 8.3691 (7), c= 11.444 (1) Å, β = 90.33 (4)°, V = 1485.7 Å3; O-methylcimiacerol is orthorhombic, space group P212121, a = 15.940 (4), b = 18.278 (6), c = 9.650 (3), V = 2811.5 Å3. Full structure determinations are in progress.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878012698
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    A simple back-reflexion camera (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 62-62 
    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/S002188987801273X
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Trial and error indexing program for powder patterns of monoclinic substances (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 60-61 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A method for finding the unit cells from the d values of powder patterns of monoclinic substances is described. An appropriate computer program based on this method is developed and combined with an already existing program [Kohlbeck & Hörl, J. Appl. Cryst. (1976). 9, 28–33] which has treated monoclinic cells as triclinic. In this way, calculation times are obtainable for monoclinic cells approximately five times shorter than those obtained with the previous program alone.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878012716
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Crystallographers (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 62-63 
    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/S0021889878012741
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Commission on Crystallographic Apparatus. Index of Crystallographic Supplies: Supplement to the third Edition (1972) (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 65-72 
    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/S0021889878012790
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Exact solution of the slit-height correction problem in small-angle X-ray scattering. II. A method for arbitrary slit transmission functions (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 98-101 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A numerical method for calculating the slit-height correction function g(t) corresponding to an arbitrary slit transmission function f(t) is presented. As shown in the previous paper [Deutsch & Luban (1978). J. Appl. Cryst. 11, 87–97], the ideal scattered intensity for pinhole collimation can be calculated given g(t) and measured scattered intensities obtained with finite slit-height collimation. The present method is tested in detail for simulated experimental data and for the rectangular transmission function [for which the exact form for g(t) can be calculated]. The calculated results for the pinhole collimation intensity are only slightly less accurate than those obtained with the exact form for g(t), and considerably more accurate than those obtained using Lake's iterative method.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878012832
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Exact solution of the slit-height correction problem in small-angle X-ray scattering. I. The general method and its accuracy in application to simulated data (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 87-97 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A general method for obtaining the exact solution of the integral equation relating the slit height correction function g(t) and the slit transmission function f(t) is presented. This is achieved by transforming the integral equation so that it is directly solvable utilizing Laplace transforms. An expression for the corrected intensity function in terms of d[g(t)/t]/dt and the measured scattered intensity, without the necessity of differentiating the latter, is also presented. The procedure is tested in detail by applying it to simulated experimental data for several experimentally relevant examples. The key ingredients tested relate to the effects of: (1) discreteness of the data; (2) availability of data for only a restricted range of scattering angles; and (3) data beset with random noise. The procedure yields highly accurate results despite all of these difficulties.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878012820
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Absolute sign of piezoelectric d33 and pyroelectric p3 coefficients in LiClO4.3H2O. (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 128-131 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The sense of the piezoelectric d33 and the pyroelectric p3 coefficients for LiClO4.3H2O crystals in point group 6 mm has been related to the absolute polarity and atomic arrangement, with the use of anomalous X-ray scattering techniques. The magnitude of d33 is about 4 × 10−12 CN−1, that of p3 about 3.9 × 10−6 Cm−2 K−1. The absolute sense of the spontaneous polarization Ps is calculated to be antiparallel to the positive c-axis direction. The sense of p3 is negative indicating that the Li+ ions become more deeply embedded in the nearest layers of ClO4− ions, and that |Ps| increases, with increasing temperature. The sense of d33 is positive, indicating that the Li+ ions become displaced further from the ClO4− ion layer under tensile stress.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878012881
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Error analysis of 2π powder data for cubic or uniaxial phases (1978)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 11 (1978), S. 184-189 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The likely error in the 2θ measurement of a particular powder reflection can be bracketed by a self-consistent error analysis. To a specific observed θm value one assigns arbitrary increments {Δθm} and calculates iteratively the corresponding increments of any other θn according to the expression: \Delta \theta_{n} = \sin^{-1} {{{q \sin (\theta_{m} + \Delta \theta_{m})-\sin \theta_{n} \cos \Delta \theta_{n}}\over{\cos \theta_{n}}}}where q is the product of the square root of the ratio of the quadratic factors for (hmkmlm) and (hnknln) and a correction factor for refraction. By considering special coincidences for which the various Δθn's are 0° or nil (0.000X°), one arrives at a likely bracketing interval for Δθm. Continuing this process one computes the indicated errors for the remaining reflections. The intent of the error analysis is to induce the experimenter to seek the cause(s) of the indicated errors in the 2θ determinations, and to delimit more precisely the accuracy of lattice constants of cubic or uniaxial phases.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889878013096
    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...