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H. Dandache 《Il Nuovo Cimento D》1989,11(10):1501-1506
Summary The semi-empirical Hugoniot equation of state is obtained by using the third-order tangency between the isentropic and the
Hugoniot curves at the origin of coordinates. The results of this model are in good agreement with Carter’s experimental data
for fourteen elements from the lanthanides series in the lower phase only.
Due to postal troubles with Lebanon, it was impossible to send proffs to the author as he requested. 相似文献
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O. D. Ziganshina M. D. Él'kin V. V. Nechaev K. V. Berezin 《Journal of Applied Spectroscopy》2004,71(5):635-640
The structure and frequencies of the normal vibrations of the molecules of porphin, Mg-, Zh-, and Ni-porphin were calculated by the density-functional method in the B3LYP/6-31G(d) approximation, and correlation of their frequencies was made. The force fields have been obtained in dependent natural coordinates. It is shown that the majority of changes in the vibrational frequencies in transition from porphin to its metal complexes correlate with changes in the structure of the pyrrole and pyrrolenine rings of the porphin ligand. 相似文献
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Nazmul Islam 《Molecular physics》2013,111(12):1533-1544
This study explored a new route for calculating the global hardness of atoms using spectroscopy. Working on a new definition of global hardness and relying on the Bohr model of the hydrogenic atom, a new formula for the global hardness of atoms was derived in terms of the wave number, reflecting the electron transition from the ground state to infinity. Since the spectral lines emitted from an atom bear the signature of all complex and complicated energetic effects, including relativity, in the internal constitution of the atom, it is expected that all such effects are automatically subsumed in the hardness data computed in terms of spectral lines. The hardness of the atoms of the 103 elements of the periodic table have been computed using spectral data and in terms of the new formula suggested in this work. The effect of relativity in pre- and post-lanthanoid elements is distinctly manifest. The express periodic behaviour and correlation of the most important physico-chemical properties of elements suggest that the present approach is an alternative scientifically meaningful method for evaluating the global hardness of atoms. 相似文献
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The dynamic properties of the lipid layer of intraplastid membranes have been studied by analyzing the stationary and kinetic spectral polarization characteristics of the fluorescence of lipophilic probes of pyrene and diphenylhexatriene (DPH). Based on the data of the decay of the fluorescence anisotropy of pyrene, the value of the microviscosity of lipids in the membranes of prolamellar bodies (PLB) and protilakoids of etioplasts has been calculated. The pyrene molecules built into the membranes of etioplasts have a relatively high rotational mobility (stationary anisotropy r
s < 0.1). The DPH molecules rotate with difficulty in etioplast membranes (r
s > 0.3). After photoreduction of protochlorophyllide (Pd) in vivo, the rotation of the pyrene and DPH molecules in the membranes of prolamellar bodies becomes easier and this leads to a decrease in r
s. Illumination raised the degree of excimerization of the pyrene immersed into lipids (exc = 337 nm), and the microsurrounding of the molecules of the probe in lipids became more hydropholic (the relationship between the vibronic maxima at 373 and 387 nm decrease). The set of data obtained points to a decrease in the microviscosity of the lipid layer of the membranes of prolamellar bodies as a result of illumination of sproutings. 相似文献
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超弹性碰撞演示实验是灵活运用大学物理知识的典型实验,本文对其最佳工作条件进行了分析,研究表明,当大球和小球的质量比为3时可以达到最佳的实验效果. 相似文献
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利用物理力学定律对“和平号”空间站坠毁过程作了比较详细的计算和描述,旨在使读者在航天器有关知识有更多了解。 相似文献
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A technique to evaluate the accuracy with which the optical parameters of thin films are determined by the method of reflectance-spectrum extrema envelopes is presented. The general case of s-polarized light impinging obliquely on a weakly absorbing thin film formed on an absorbing substrate is discussed. Rather simple analytical expressions are derived which can easily be used in program realization on computers for calculating errors. On the basis of the error analysis, a procedure for determining the optical constants and thickness of thin films is proposed, which allows one to reach the maximum accuracy in solving the inverse problem of spectrophotometry. The optical constants and the thicknesses of the films of perylenetetracarboxylic acid and 2-[4-(4-aminophenyl)phenyliminomethyl]phenol formed on silicon substrates are found by the developed technique in the spectral range 550–900 nm. 相似文献
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近来有些文章断言,在一个惯性参考系里能量守恒的物理系统,在别的参考系看来能量也一定守恒.实际上这些作者混淆了物理方程式的协变性和相对性原理.本文将澄清这一误解. 相似文献
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In this work, we make an investigation on the preferences of
orientations between amino acids using the orientation defined based
on the local geometry of the amino acids concerned. It is found that
there are common preferences of orientations
(70°, 30°}, 140°) and
(110°, 340^{\circ}, 100°) for various pairs of
amino acids. Different side chains may strengthen or weaken the
common preferences, which is related to the effect of packing. Some
amino acids having specific local flexibility may possess some
preferences of orientations besides the common ones, such as
(10°, 280°, 210°). Another analysis on the
pairs of the amino acids with different secondary-structure
preferences shows that the directional interaction may affect the
distribution of orientation more effectively than the packing or
local flexibility. All these results provide us some insight of the
organization of amino acids in protein, and their relation with some
related interactions. 相似文献
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Summary A numerical method is described which allows one to obtain the solutions of the linearized Navier-Stokes equation for the
case of wave motion at the air-water interface in the presence of both soluble and insoluble films. The results are shown,
and we discuss evidence of two vibration modes,i.e. transversal and longitudinal waves. Their behaviour appears to be closely linked, especially in the case of insoluble films.
Riassunto Viene descritto un metodo numerico che permette di ottenere le soluzioni dell'equazione di Navier-Stokes linearizzata nel caso di moto ondoso all'interfaccia aria-acqua in presenza di film solubili ed insolubili. Sono mostrati i risultati e si discute l'evidenza di due modi vibrazionali,i.e. onda longitudinale e trasversale. Il loro comportamento appare strettamente correlato, specialmente nel caso di film insolubili.
Резюме Описывается численный метод, который позволяет получить решения линеаризованного уравнения Навье-Стокса для случая волнового движения границы раздела воздух-вода при наличии растворимых и нерастворимых пленок. Приводятся результаты, и мы обсуждаем появление двух колебательных мод, т.е. поперечных и продольных волн. Показывается, что их поведение тесно связано, особенно в случае нерастворимых пленок.相似文献
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Algirdas Audzijonis Gediminas Gaigalas Leonardas Žigas Audrius Pauliukas Bronislovas Šalkus Raimundas Žaltauskas Antanas Kvedaravičius Aurimas Čerškus Jurgis Narušis 《Central European Journal of Physics》2008,6(3):415-421
The energy levels of valence bands (VB) in SbSeBr crystals were calculated for investigation of the photoelectron emission
spectra of A5B6C7 — type crystals. The molecular model of this crystal was used for calculation of VB by the Density Functional Theory (DFT)
and Unrestricted Hartree — Fock (UHF) methods. The molecular cluster consisting of 20 molecules of SbSeBr was used for calculations
of averaged total density of states including atom vibrations. The spectra of averaged total density of states from VB in
the SbSeBr cluster were compared with experimental photoelectron emission spectra from VB of A5B6C7 — type crystals. The results of comparison clarify that the atomic vibrations are one of possible reasons for the smoother
appearance of the experimental X-ray photoelectron spectrum (XPS).
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In the relativistic σ-ω model, the influences of the parameters b, c, d in the potential U(σ) = (1/2!)bo2 - -(1/3!)cσ3 (1/4!)dσ4 to the incompressibility, effective mass and binding energy of the nuclear matter are studied in detail.The calculation of equation of state of nuclear matter shows that the values of b, c, d depend on the renormalization condition, we also find that a soft equation of state of nuclear matter can be obtained in a suitable renormalization condition, and the experimental incompressibility coefficient can be reproduced. These results are also used to study the thermal properties of hot A-resonant nuclear matter.self-interaction of σ meson, renormalization, hot and dense hadronic matter `` 相似文献
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In this study, we investigate the entropies of photons, ideal gas-like dust (baryonic matter), and a special kind of dark energy in the context of cosmology. When these components expand freely with the universe, we calculate the entropy and specific entropy of each component from the perspective of statistics. Under specific assumptions and conditions, the entropies of these components can satisfy the second law of thermodynamics independently. Our calculations show that the specific entropy of matter cannot be a constant during the expansion of the universe, except for photons. When these components interact with the space-time background, particle production (annihilation) can occur. We study the influence of the interaction on the entropies of these components and obtain the conditions guaranteeing that the entropy of each component satisfies the second law of thermodynamics. 相似文献