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
  • Wiley  (41)
  • Wiley-Blackwell  (31)
  • Springer Nature  (10)
  • International Union of Crystallography (IUCr)  (6)
  • American Institute of Physics (AIP)  (4)
  • 1995-1999  (84)
  • 1955-1959  (8)
Collection
Keywords
Publisher
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    A multioctave coaxially oriented beam-resonator arrangement Fourier-transform microwave spectrometer (1996)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 67 (1996), S. 4072-4084 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: The design, performance, and operation of a broadband (3–26.5 GHz) high resolution microwave spectrometer is described. In comparison to previously developed molecular beam Fabry–Perot resonator spectrometers the design presented here implements some significant improvements: a coaxially oriented beam resonator arrangement (COBRA) formed by a confocal pair of mirrors incorporating an electromechanical valve and employing two pairs of microwave antennas, and a multioctave Fourier-transform microwave (FTMW) instrument providing the pulsed excitation source with microwave pulse phase-inversion scheme and the low-noise receiving system employing image-rejection downconversion with superheterodyne as well as quadrature detection. The entire apparatus, fully automated for scanning operation, covers a frequency range of more than three octaves. The novel design of the FTMW instrument does not require any changes of the spectrometer hardware in order to reach all regions of its spectral range. While operated in high resolution mode the COBRA-FTMW spectrometer is achieving a linewidth (half-width at half-height, HWHH) relative to the molecular emission frequency of better than 10−7 HWHH. The sensitivity and resolution of the spectrometer is demonstrated by several examples. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1147553
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    A local variational theory for the Schmidt metric (1997)
    College Park, Md. : American Institute of Physics (AIP)
    Journal of Mathematical Physics 38 (1997), S. 3347-3357 
    Details
    ISSN: 1089-7658
    Source: AIP Digital Archive
    Topics: Mathematics , Physics
    Notes: We study local variations of causal curves in a space-time with respect to b-length (or generalized affine parameter length). In a convex normal neighbourhood, causal curves of maximal metric length are geodesics. Using variational arguments, we show that causal curves of minimal b-length in sufficiently small globally hyperbolic sets are geodesics. As an application we obtain a generalization of a theorem by Schmidt, showing that the cluster curve of a partially future imprisoned, future inextendible and future b-incomplete curve must be a null geodesic. We give examples which illustrate that the cluster curve does not have to be closed or incomplete. The theory of variations developed in this work provides a starting point for a Morse theory of b-length. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.532047
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    The nuclear quadrupole coupling constants and the structure of the para–para ammonia dimer (1995)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 102 (1995), S. 8693-8703 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Expressions are derived for the nuclear quadrupole splittings in the E3 and E4 (para–para) states of (NH3)2 and it is shown that these can be matched with the standard expressions for rigid rotors with two identical quadrupolar nuclei. The matching is exact only when the off-diagonal Coriolis coupling is neglected. However, the selection rules for rotational transitions are just opposite to those for the rigid rotor. Hyperfine splittings are measured for the J=2←1 transitions in the E3 and E4 states with ||K||=1; the quadrupole coupling constants χaa=0.1509(83) MHz and χbb−χcc=2.8365(83) MHz are extracted from these measurements by the use of the above mentioned correspondence with the rigid rotor expressions. The corresponding results are also calculated, with and without the Coriolis coupling, from the six-dimensional vibration–rotation–tunneling (VRT) wave functions of (NH3)2, which were previously obtained by Olthof et al. [E.H.T. Olthof, A. van der Avoird, and P.E.S. Wormer, J. Chem. Phys. 101, 8430 (1994)]. From the comparison of χaa with the measured value it follows that the semiempirical potential and the resulting VRT states of Olthof et al. are very accurate along the interchange (cursive-thetaA,cursive-thetaB) coordinate. From χbb−χcc it follows that this potential is probably too soft in the dihedral angle γ¯=γA−γB, which causes the torsional amplitude to be larger than derived from the experiment. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.468972
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    The structure of phenol(H2O) obtained by microwave spectroscopy (1996)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 104 (1996), S. 967-971 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The microwave spectrum of phenol(H2O) has been recorded using a pulsed molecular beam Fourier transform microwave spectrometer. Twenty a-type transitions have been observed and assigned. All a-type transitions are doublets with splittings varying from 1.13 to 4.01 MHz. These splittings are interpreted to result from the internal rotation of the water molecule. The ground state of this torsional motion is split into two levels with different spin statistical weights. Both torsional levels are treated independently as asymmetric rotor states. The resulting rotational constants are A=4291.486 MHz, B=1092.1484 MHz, and C=873.7263 MHz for the lower torsional level (σ=0) and A=4281.748 MHz, B=1092.329 55 MHz, and C=873.906 81 MHz for the upper level (σ=1). A fit of the molecular structure is performed by optimizing the intermolecular OO distance and two angles, describing the H-bonding arrangement. The resulting trans-linear structure is in reasonable agreement with the ab initio calculations © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.470820
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Aminoguanidinium Squarate (1997)
    Oxford [u.a.] : International Union of Crystallography (IUCr)
    Acta crystallographica 53 (1997), S. 0-0 
    Details
    ISSN: 1600-5759
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0108270197099460
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    2-Benzoyl-2-methyl-1,3-dithiane (1999)
    Oxford [u.a.] : International Union of Crystallography (IUCr)
    Acta crystallographica 55 (1999), S. 2179-2182 
    Details
    ISSN: 1600-5759
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S010827019901135X
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    A Synchrotron X-ray Study of Ferroelectric Switching, Domain Reversal and Piezoelectric Moduli in CsTiOAsO4, Under an Applied Electric Field (1997)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 30 (1997), S. 383-387 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Single crystals of caesium titanyl arsenate (CTA, CsTiOAsO4), with space group Pna21 and isomorphous with potassium titanyl phosphate (KTP, KTiOPO4), have been studied using high-resolution synchrotron X-rays. During the experiments, an electric field was applied along the polar axis [001]. Single-crystal plates, between 300 and 450 μm thick along [001], were polarized by a variable square wave of frequency 20 Hz alternately applied to each side of the plate. A field-induced splitting of the + /− peaks for reflections hkl with l ≠ 0 was observed. This splitting provides information about the coercive field, polarizability and the piezoelectric strain tensor. Two of the piezoelectric coefficients of CTA could be estimated as d31 ∼ 1 and d33 ∼ 27 pm V−1. Whereas the coercive fields were estimated at 2300 V mm−1, the field necessary to reverse the domains just once in CTA was found to be either 560 or 1550 V mm−1, depending on the polarity of the reversed domain in relation to the polarity of the nonswitched part of the crystal.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889897000708
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Cation ordering waves in trirutiles. When X-ray crystallography fails? (1995)
    [S.l.] : International Union of Crystallography (IUCr)
    Acta crystallographica 51 (1995), S. 514-519 
    Details
    ISSN: 1600-5724
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: Trirutiles are AB2O6 crystal structures with a tripled c-axis repeat compared to the rutile type, owing to ABBABBA metal ordering. Partially disordered trirutiles, space group P42/mnm, are here described by addition of a sinusoidal scattering density wave along c to the basic rutile structure. As a result of this approach, an infinite number of crystal structures can be envisaged, which pairwise exhibit identical X-ray diffraction patterns, i.e. this is a case where the expected one-to-one relationship between crystal structure and diffraction intensity distribution is replaced by a two-to-one relationship
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0108767395003618
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Separation and crystallization of T = 3 and T = 4 icosahedral complexes of the hepatitis B virus core protein (1999)
    Copenhagen : International Union of Crystallography (IUCr)
    Acta crystallographica 55 (1999), S. 717-720 
    Details
    ISSN: 1399-0047
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: The icosahedral nucleocapsid of human hepatitis B virus is a homopolymer of the dimeric capsid protein also known as hepatitis B core antigen or HBcAg. Purified capsid protein obtained from an Escherichia coli expression system was reassembled into a mixture of T = 3 and T = 4 icosahedral particles consisting of 90 and 120 dimers, respectively. The two types of capsid were separated on a preparative scale by centrifugation through a sucrose gradient. In addition to this heterogeneity, the capsid protein has three cysteines, one of which has a great propensity for forming disulfide bonds between the two subunits, forming a dimer. To eliminate heterogeneity arising from oxidation, alanines were substituted for the cysteines. T = 3 and T = 4 capsids crystallized under similar conditions. Crystals of T = 3 capsids diffracted to ∼8 Å resolution; crystals of T = 4 capsids diffracted to 4 Å resolution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S090744499801350X
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Rutile Superstructure of Sb0.9V1.1O4 (1997)
    Copenhagen : International Union of Crystallography (IUCr)
    Acta crystallographica 53 (1997), S. 221-230 
    Details
    ISSN: 1600-5740
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: The structure of Sb0.9V1.1O4, antimony vanadium oxide, has been studied by powder X-ray diffraction, electron diffraction and high-resolution electron microscopy (HREM). The X-ray powder diffraction pattern showed only basic rutile reflections [ar = 4.6085 (1), cr = 3.0867 (1) Å] and the basic rutile structure was refined using the Rietveld method. A rutile superstructure was revealed when the sample was studied by electron diffraction. The electron diffraction patterns were indexed on the unit cell a = 21/2ar, b = 21/2br, c = 2cr. Its space group, I41md, was determined by means of convergent-beam electron diffraction (CBED). A structural model based on alternating cation ordering along c in the chains of edge-sharing octahedra is proposed and its electron diffraction patterns and HREM image are calculated and matched with the experimental ones.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0108768196012955
    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...