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
  • 1
    Electronic Resource
    Electronic Resource
    Concentration dependence of polymer dimensions. I. Theoretical access based on empirical laws for the dimensions in chain pairs with I-tuples of intermolecular overlaps (1987)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 87 (1987), S. 1433-1439 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: An analysis of the configuration of pairs of self-avoiding five-way cubic lattice chains has revealed that on average the relative (squared) chain dimensions XI associated with any I- tupel of intermolecular overlaps (double occupancies) within fair limits of accuracy may be treated as an arithmetic series, ΔXI=(I−1)ΔX2, or, alternatively, also as a geometric series, XI=XI−12, for not too large values of I. Based on these findings comparatively simple expressions for the coefficient characterizing the first order concentration dependence kX of the squared end-to-end distance and the squared radius of gyration have been developed built up from X2 and the excluded volume functions h(z) and ψ(z) for the arithmetic series case, or h(z) and h(X2z), for the geometric series case, respectively. kX values calculated according to these expressions coincide well with those evaluated directly for lattice chains and exhibit at least fair agreement with those evaluated experimentally by SANS of SAXS techniques for real polymers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.453272
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Some results from a Mellin transform expansion for the heat kernel (1989)
    College Park, Md. : American Institute of Physics (AIP)
    Journal of Mathematical Physics 30 (1989), S. 1226-1229 
    Details
    ISSN: 1089-7658
    Source: AIP Digital Archive
    Topics: Mathematics , Physics
    Notes: In the case of a differential operator containing a gauge field, coefficients of a new heat kernel expansion obtained in a preceding paper (A. P. C. Malbouisson, M. A. R. Monteiro, and F. R. A. Sima˜o, CBPF-NF-024/88, to be published in J. Math. Phys.) are calculated. The prior expansion allows it to be shown that the meromorphic structure of the generalized zeta function is much richer than was known previously. Also, an application to anomalies is done, resulting in a general formula for the arbitrary dimension D. The special cases D=2 and D=3 are investigated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.528348
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Orientational order in two-component plastic crystals 2,2-dichloropropane–carbon tetrachloride (1991)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 95 (1991), S. 22-27 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: 1H nuclear magnetic resonance (NMR) spectra and birefringence of noncubic plastic single crystals (CH3)2CCl2–CCl4 have been measured. The investigation has demonstrated that in these crystals weak preferred orientations of molecules were observed. Concentration dependence of orientational ordering matrix of (CH3)2CCl2 molecules has been obtained from computer simulations of NMR line shape and birefringence data. It has been found that all ordering matrix elements become zero at mole fraction of 2,2-dichloropropane 0.5.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.461480
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Mechanism of dust-acoustic instability in a direct current glow discharge plasma (2000)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 7 (2000), S. 1374-1380 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: An observation of low frequency waves spontaneously excited in a dc glow discharge dusty plasma is reported. To analyze possible reasons for the instability observed, a linear dispersion relation which takes into account collisions with neutrals, dust grain charge variations, ion drift, and forces acting on dust particles is derived. Numerical analysis of the dispersion relation shows that the observed instability is the result of dust charge variations in the presence of external charge-dependent forces together with the ion drift effect. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.873954
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Ab initio calculation of band structure, x-ray emission, quantum yield, and electron-energy-loss spectra of hexagonal boron nitride (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 7422-7426 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The band structure of hexagonal boron nitride (BN) has been calculated using an ab initio linear combination of pseudoatomic-orbitals method. The calculated band structure confirms a previous finding that this material is an indirect band-gap insulator and has two empty interlayer bands. Projected densities of states are compared with the experimental x-ray emission spectra of B and N K edges and the agreement is good. This good agreement between the present ground-state calculation and the experimental x-ray emission spectra supports our previous finding that there should be very little valence electron relaxation effect on x-ray emission spectra. A real-space Green's function technique and the Z+1 approximation have been used to calculate the exciton spectra of B and N K edges. The first peak at 192 eV in B K edge is found to be a bound exciton with a binding energy of 1.7±0.4 eV. Only resonance is found for the N K edge. The calculated exciton spectra agree very well with the experimental quantum-yield and electron-energy-loss spectra.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.353983
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Analysis of the single-particle scattering spectra for spin-density fluctuations of electrons in n-GaAs at T=300 K (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 3023-3027 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The line shapes of single-particle scattering spectra for spin-density fluctuations of electrons in n-GaAs with carrier concentrations ranging from 5×1015 to 7×1017 cm−3 have been analyzed. We have found that the Raman line shapes can be very well explained by a theory developed by Hamilton and McWhorter which takes into account both the band-structure effects in semiconductors and the effects of carrier collision in a relaxation time approximation. For carrier concentration n≥2×1016 cm−3, the effects of finite collision time has been demonstrated to be very important and these effects must be properly taken into account in order to satisfactorily interpret the line shapes of single-particle scattering spectra for spin-density fluctuations in n-GaAs at T=300 K. We show that although Lindhard–Mermin's expression for dielectric constant as well as Hamilton and McWhorter's theory fit the Raman line shapes equally well for carrier density n=7×1017 cm−3, neglect of band-structure effects of the former tends to underestimate the carrier collision time. An interpretation of the deduced collision time in terms of electron-electron, electron-impurity, and electron-phonon scattering is also given.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.353008
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Epitaxial growth and characterization of Y2Co17(0001) thin films deposited on W(110) (1995)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 78 (1995), S. 997-1003 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Y2Co17(0001) was grown on W(110) by pulsed laser deposition. The structural and morphological features of the films as a function of substrate temperature and thickness were studied in situ by means of reflection high-energy electron diffraction, and ex situ by means of scanning electron microscopy, transmission electron microscopy, and x-ray analysis (diffraction and reflection). Different growth modes were observed depending on the experimental conditions. They are discussed by considering the kinetical properties of the deposit and the thermodynamical properties of the system. The magnetic properties of the films have been investigated and related to the structural analysis. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.360294
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Breakdown of hydrodynamics in the classical 1D Heisenberg model (abstract) : 37th Annual conference on magnetism and magnetic materials (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 5504-5504 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Extensive spin-dynamics simulations have been performed to study the dynamical behavior of the classical Heisenberg chain at infinite temperatures and long wavelengths. We find that the energy and spin show distinctly different dynamics in the isotropic system. The energy correlation function follows the classical diffusion theory prediction, namely, it decays exponentially with q2t. In contrast, the spin correlation function is found to decay exponentially as q2.12t ln t implying a logarithmically divergent diffusion constant and the failure of the usual hydrodynamic assumptions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.353682
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Theoretical comparison of electron energy-loss and x-ray absorption near-edge fine structure of the Si L2,3 edge (1990)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 68 (1990), S. 288-290 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Various approximations in the calculations of electron energy-loss cross section and x-ray absorption coefficient have been evaluated using the Si L2,3 edge as an example. It was found that the random phase approximation, for which the cross terms are neglected in the expressions of electron energy-loss cross section and x-ray absorption coefficient, is a very good approximation. The dipole approximation in the calculation of the electron energy-loss cross section was found to begin to break down even at small acceptance half angles, such as 12.5 mrad. For energy losses larger than that of the Si L2,3 edge the dipole approximation will break down faster. This approximation also fails for a large scattering angle even at a small energy loss. The electron energy-loss cross section and x-ray absorption coefficient of the Si L2,3 edge has been calculated and compared. The large difference in relative intensity reported experimentally between the two spectra is not confirmed in this study. More experimental comparisons between electron energy loss and x-ray absorption spectra are recommended for Si and other compounds.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.347129
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Influence of the spatial distribution of reactive centers on diffusion controlled reactions (1992)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 97 (1992), S. 156-161 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The influence of the spatial distribution of fixed reactive centers on the diffusion controlled kinetics of reagent particles is investigated on the basis of a mean-field method for the reaction rate. The reaction kinetics are analyzed in systems where the reactive centers are randomly distributed on the sphere, a line, an array of lines, and other geometrical structures imbedded in two and three dimensions. Finite-size effects influence the time dependence of the reaction rate on different time scales as a result of the competition for the diffusing particles by the fixed reactive centers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.463615
    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...