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1.
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   

2.
测量可溶性物质的密度   总被引:1,自引:0,他引:1  
饶黄云 《物理实验》2001,21(12):32-34
常规方法测量可溶性物质(如食盐)的密度遇到了困难,经过分析研究和实验检测,本文给出的3种实验方法的确可行,实验结果误差较小。  相似文献   

3.
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   

4.
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   

5.
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   

6.
熊锦  牛中奇  张智明 《物理学报》2002,51(10):2245-2244
考虑JaynesCummings模型中与光场相互作用的原子为超冷原子,讨论了原子质心运动的量子效应对光场两正交分量量子噪声压缩的影响,结果表明,在JaynesCummings模型中,原子质心运动的量子效应增加光场两正交分量的量子噪声,使其压缩效应消失 关键词: 超冷原子 质心运动的量子效应 光场量子噪声压缩  相似文献   

7.
路峻岭  汪荣宝 《大学物理》2005,24(10):27-28
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   

8.
毕靖芳 《大学物理》2002,21(8):38-39,F003
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   

9.
从2005年诺贝尔物理学奖出发,考察了已往和长度基准有关的诺贝尔物理学奖,从物理学史的角度.探讨了长度基准的历史沿革及其意义.  相似文献   

10.
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   

11.
利用偏振度研究散射介质浓度及杂质比的数值分析   总被引:1,自引:2,他引:1  
赵一鸣  江月松  路小梅 《光学学报》2007,27(12):2110-2116
为了研究散射介质的粒子数浓度对散射光偏振度的影响以及杂质混合比与目标偏振度的关系,求解了当激光器输出波长处于近红外波段806 nm时目标的米勒矩阵及偏振度的数值解,结果表明偏振度随散射介质粒子数浓度的变化十分显著;通过建立混合目标模型,讨论了杂质比与偏振度的数值关系,并对目标的偏振度进行了归一化,而且实现了由归一化偏振度对杂质混合比的反演。本文的研究结果为利用散射光偏振度研究大气遥感提供了新的途径。  相似文献   

12.
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   

13.
波导弯曲半径与弯曲损耗的关系   总被引:4,自引:4,他引:4  
介绍了分析波导弯曲损耗的保形变换法和归一化方法以及由此得到的波导弯曲半径与弯曲损耗的关系式.建立了弯曲损耗经验公式,由该公式得出了四种常用材料的波导弯曲半径与弯曲损耗的曲线,并将已报道的相应材料制作的AWG中的最小弯曲半径及其对应的损耗实验数据与这些曲线上的相应数值进行了比较,结果表明,弯曲损耗经验公式在确定AWG中的最小弯曲半径时,有一定的参考价值.  相似文献   

14.
陈颖  王骏  王炜 《中国物理》2007,16(3):868-875
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   

15.
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   

16.
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).   相似文献   

17.
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   

18.
吕秋捷  陈茵  陆申龙 《物理实验》2002,22(11):34-37
介绍第第3届亚洲物理奥林匹克竞赛力学实验试题及解答,并分析了该实验的设计思想、特点与要求。  相似文献   

19.
从能量的角度讨论两体碰撞问题   总被引:10,自引:3,他引:7  
王长春 《大学物理》2005,24(9):18-19,22
从能量角度导出了两体对心碰撞的能量损失公式,重新讨论了恢复系数的物理意义.  相似文献   

20.
Hao Yu  Yu-Xiao Liu  Jin Li 《中国物理C(英文版)》2023,47(5):055105-055105-20
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   

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