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121.
N. Leonard H. M. Smith L. K. Boseley A. K. Miller J. P. Potts Ch. G. Matthews A. H. Parker und W. Bersch 《Fresenius' Journal of Analytical Chemistry》1906,45(5-6):394-396
Ohne Zusammenfassung 相似文献
122.
Abdul G. Al Lafi James N. Hay David J. Parker 《Journal of Polymer Science.Polymer Physics》2008,46(11):1094-1103
Amorphous poly(ether‐ether‐ketone) (PEEK) progressively crosslinks on irradiation with 11.0 MeV protons, and this has a marked effect on the extent of crystallinity that subsequently develops and on the kinetics of the high temperature isothermal crystallization. The extent of crystallinity with time was analyzed using the Avrami equation, and the temperature dependence of the rate constants was analyzed in terms of nucleation theory. While irradiation inhibits the overall rates of crystallization by the reduction in the mobility of the chain segments as observed by the progressive increase in the glass transition temperature, it also alters the fold surface free energy. The observed melting points were consistent with depression of the equilibrium melting point by the crosslinks produced by irradiation. These two effects alone are sufficient to account for the inhibition of crystallization on irradiation of PEEK by protons. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 1094–1103, 2008 相似文献
123.
J. G. Parker E. E. M. Payne und Kommission der internationalen Vereinigung der Leder-Chemiker 《Fresenius' Journal of Analytical Chemistry》1906,45(12):773
Ohne Zusammenfassung 相似文献
124.
O. Redlich H. C. Parker M. Randall G. N. Scott I. Remesow G. Jander O. Pfundt H. Schorstein W. R. G. Atkins Fr. L. Hahn R. Klockmann und K. Someya 《Fresenius' Journal of Analytical Chemistry》1931,85(7-8):275-286
Ohne Zusammenfassung 相似文献
125.
126.
Linear elastic surface waves are nondispersive. All wavelengths travel at the Rayleigh wave speed c
R. This absence of frequency dispersion means that nonlinear waves of permanent form cannot be determined as a small perturbation from a sinusoidal wavetrain. By representing the general Rayleigh wave of the linear theory in terms of a pair of conjugate harmonic functions, waves which propagate without distortion are characterized as those having surface elevation profiles which satisfy a certain nonlinear functional equation. In the small-strain limit, this reduces to a quadratic functional equation. Methods for the analysis of this equation are presented for both periodic and nonperiodic waveforms. For periodic waveforms, the infinite system of quadratic equations for the Fourier coefficients of the profile is solved numerically in the case of a certain harmonic elastic material. Two distinct families of profiles having phase speed differing from the linearized Rayleigh wave speed are found. Additionally, two families of exceptional waveforms are found, describing profiles which travel at the Rayleigh wave speed. 相似文献
127.
Vidma KV Bogdanchikov GA Baklanov AV Chestakov DA Parker DH 《The Journal of chemical physics》2010,133(19):194306
Van der Waals binding energies for the X-O(2) complexes (X=Xe, CH(3)I, C(3)H(6), C(6)H(12)) are determined by analysis of experimental velocity map imaging data for O((3)P(2)) atoms arising from UV-photodissociation of the complex [A. V. Baklanov et al., J. Chem. Phys. 126, 124316 (2007)]. Several dissociation pathways have been observed, we focus on the channel corresponding to prompt dissociation of X-O(2) into X+2O((3)P) fragments, which is present for complexes of O(2) with all partners X. Our method is based on analysis of the kinetic energy of all three photofragments, where the O atom kinetic energy was directly measured in the experiment and the kinetic energy of the X partner was calculated using momentum conservation, along with the measured angular anisotropy for O atom recoil. We exploit the fact that the clusters are all T-shaped or nearly T-shaped, which we also confirm by ab initio calculations, along with knowledge of the transition dipole governing radiative absorption by the complex. The effect of partitioning the kinetic energy between translation along the X-O(2) and O-O coordinates on the angular anisotropy of the O atom recoil direction is discussed. Van der Waals binding energies of 110±20 cm(-1), 280±20 cm(-1), 135±30 cm(-1), and 585±20 cm(-1) are determined for Xe-O(2), CH(3)I-O(2), C(3)H(6)-O(2), and C(6)H(12)-O(2) clusters, respectively. 相似文献
128.
We have used high resolution neutron vibrational spectroscopy to study the vibrations of the model compound for arene-to-metal bonding, benzene chromium tricarbonyl, and its mesityl analogue. It is shown that all previously published assignment schemes, based on optical spectroscopy alone, are wrong, and new assignments are given in agreement with ab initio calculations. 相似文献
129.
Catalytic ignition of ionic liquids for propellant applications 总被引:1,自引:0,他引:1
Shamshina JL Smiglak M Drab DM Parker TG Dykes HW Di Salvo R Reich AJ Rogers RD 《Chemical communications (Cambridge, England)》2010,46(47):8965-8967
In this proof of concept study, the ionic liquids, 2-hydroxyethylhydrazinium nitrate and 2-hydroxyethylhydrazinium dinitrate, ignited on contact with preheated Shell 405 (iridium supported on alumina) catalyst and energetically decomposed with no additional ignition source, suggesting a possible route to hydrazine replacements. 相似文献
130.
Inflation provides a natural mechanism to account for the origin of cosmic structures. The generation of primordial inhomogeneities
during inflation can be understood via the spontaneous creation of quanta from the vacuum. We show that when the corresponding
stimulated creation of quanta is considered, the characteristics of the state of the universe at the onset of inflation are
not diluted by the inflationary expansion and can be imprinted in the spectrum of primordial inhomogeneities. The non-gaussianities
(particularly in the so-called squeezed configuration) in the cosmic microwave background and galaxy distribution can then
tell us about the state of the universe that existed at the time when quantum field theory in curved spacetime first emerged
as a plausible effective theory. 相似文献