Distribution of zeros of the partition function of the lattice gases of fisher and of temperley

The distributions of zeros of the partition function of lattice gas models of Fisher (at some temperature) and of Temperley are obtained. The former is a closed loop crossing the real axis and the latter is a part of the negative real axis.     

混合物物态方程的计算

 在采用体积相加原理计算混合物物态方程的基础上,建立了一种物理模型确定混合物温度。根据混合物中各组分温度和压强平衡条件,采用压强-密度迭代方法计算给出混合物物态方程,编制了两种组分的混合物物态方程计算程序。为检验建立的温度模型的合理性及程序的有效性,分析了不同密度、温度状态的氢（H2）和钨（W）组成的混合物状态参量,计算了以下情形及其组合情形的混合物物态方程：H₂和W以不同质量比混合;质量比固定,单组分状态不同;温度区间和密度区间不同。研究表明:实际应用中在建立的混合物温度模型基础上确定的混合物物态方程是合理的。     

Calculation of energy characteristics of adsorption of metals

Within the framework of the electron density functional, a technique is developed for calculation of the adsorption energy and variation in the electron work function for metal substrates due to metal atom adsorption. The corrections to the local density approximation, which are associated with non-uniformity of the electron density in the subsurface region and discontinuous ion charge distribution over the crystal lattice sites, are included into consideration. It is shown that adsorption of alkali metal atoms results in lower electron work function, while that of transition metals (cobalt, iron, and chromium) might both decrease and increase the electron work function. Formation of a variety of adsorption structures from metal atoms depending on the temperature is discussed. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 14–19, July, 2007.     

BSA-SDS-Ag聚合物纳米微粒的制备及其水凝胶性质的研究（Ⅰ）

报道了BSA－SDS－Ag聚合物纳米微粒的制备及水凝胶的性质,用X射线衍射（XRD）、透射电镜（TEM）、傅里叶变换红外（FT－IR）光谱考察了这种聚合物微粒的结构,微粒粒径32nm左右,用UV／Vis光谱及SEM考察了冰凝胶的性,表明Ag^ 离子先与BSA产生化学键合,再学原了Ag粒,进行聚合成网状结构的聚合物。     

混合物状态方程的计算

多介质流体动力学过程的数值模拟往往涉及混合物状态方程的计算. 做图法和Newton 法是混合物状态方程计算常采用的方法, 前者虽直观精度却差, 后者计算效率高却只具有局部收敛性, 当解与其初始猜测值相差较远时Newton法不一定能够获得收敛解. 为此, 本文给出一种具有大范围收敛性的嵌入算法(imbedding method)求解混合物状态方程, 其基本思想是通过引入嵌入参数, 将待解的混合物状态方程和易解的混合物状态方程线性组合, 构成嵌入方程组, 当嵌入参数从0连续地变化到1 时, 嵌入方程组的解由易解的混合物状态方程的解连续地变化为待解的混合物状态方程的解. 嵌入方程组可由Newton法迭代求解, 也可转化为以嵌入参数为自变量的常微分方程组, 从而易于由成熟的计算方法如梯形法等进行求解. 进一步利用热力学基本关系, Maxwell形式的微分方程描述了压力和温度随嵌入参数的演化速率与应变速率和组分质量分数演化速率的关系. 对铅锡混合物热力学量的计算表明了本文算法的有效性.     

Effect on zero drift of accuracy of reciprocal tuning of elements of fiber-optic interferometer

The effect of the accuracy of reciprocal tuning of the elements of a fiber-optic interferometer (FOI) — laser, polarizer, and eigenaxes of single-mode-fiber (SMF) birefringence — is examined. It is shown that zero drift in the FOI consists of two parts — a constant part and a temperature-related variable part. Both of these parts are functions of the polarization state of the radiation at the entrance to the polarizer, the extinction coefficient of the polarized, and the orientation of the SMF eigenaxes with respect to the polarizer. The variable part of the zero drift is also a function of the birefringence and h-parameter of the SMF and the width of the radiation-source spectrum. Numerical estimates of FOI zero drift are made.Institute of Applied Physics, Academy of Sciences of the USSR. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 34, No. 7, pp. 817–824, July, 1991.     

Influence of rate of change of frequency on the overall pitch of frequency-modulated tones

The mechanism(s) determining pitch may assign less weight to portions of a sound where the frequency is changing rapidly. The present experiments explored the possible effect of this on the overall pitch of frequency-modulated sounds. Pitch matches were obtained between an adjustable unmodulated sinusoid and a sinusoidal carrier that was frequency modulated using a highly asymmetric function with the form of a repeating U or inverted U shaped function. The amplitude was constant during the 400-ms presentation time of each stimulus, except for 10-ms raised-cosine onset and offset ramps. In experiment 1, the carrier level was 50 dB SPL and the geometric mean of the instantaneous frequency of the modulated carrier, fc, was either 0.5, 1, 2, or 8 kHz. The modulation rate (fm) was 5, 10, or 20 Hz. The overall depth (maximum to minimum) of the FM was 8% of fc. For all carrier frequencies, the matched frequency was shifted away from the mean carrier frequency, downwards for the U shaped function stimuli and upwards for the repeated inverted U shaped function stimuli. The shift was typically slightly greater than 1% of fc, and did not vary markedly with fc. The effect of fm was small, but there was a trend for the shifts to decrease with increasing fm for fc = 0.5 kHz and to increase with increasing fm for fc = 2 kHz. In experiment 2, the carrier level was reduced to 20 dB SL and matches were obtained only for fc = 2 kHz. Shifts in matched frequency of about 1% were still observed, but the trend for the shifts to increase with increasing fm no longer occurred. In experiment 3, matches were obtained for a 4-kHz carrier at 50 dB SPL. Shifts of about 1% again occurred, which did not vary markedly with fm. The shifts in matched frequency observed in all three experiments are not predicted by models based on the amplitude- or intensity-weighted average of instantaneous frequency (EWAIF or IWAIF). The shifts (and the pitch shifts observed earlier for two-tone complexes and for stimuli with simultaneous AM and FM) are consistent with a model based on the assumption that the overall pitch of a frequency-modulated sound is determined from a weighted average of period estimates, with the weight attached to a given estimate being inversely related to the short-term rate of change of period and directly related to a compressive function of the amplitude.     

应用振动光谱技术检测鉴定微生物的研究进展

振动光谱（红外光谱和拉曼光谱）技术与化学计量学相结合的方法对微生物进行分类、鉴定和无损检测,该方法快速简便、准确度高、仅需微量样品和少量化学试剂、对样品本身没有损害。介绍了振动光谱技术在微生物鉴定检测中的工作原理、关键技术和应用,并对该方法存在的问题和研究前景进行了分析和展望。     

傅里叶望远镜外场实验性能改进和结果分析

为了实现对傅里叶望远镜成像系统更接近实际的仿真,改进了外场实验系统结构。采用反射式目标,利用准直扩束镜替代空间滤波器和准直透镜,使用大靶面电荷耦合器件作为监视器。在无大气和包含200m水平大气两种情况下,分别对2.5mm的4种不同空间频谱分布目标进行实验。实验选用9×9,17×17,33×33和65×65傅里叶分量分别进行重构。最高成像角分辨率为3.5″。结果表明含大气与无大气重构结果的Strehl比值相近,从而证明傅里叶望远镜成像系统能够克服下行链路低阶大气扰动的影响。     

Correlation of cytotoxicity and depth of necrosis of the photoproducts of photogem®

Photodynamic therapy (PDT) is an approved modality for cancer treatment, which involves the administration of a photosensitive drug (PS) that is selectively accumulated in neoplastic tissues and their vasculature and subsequently can be activated with light at the appropriate wavelength to generate reactive molecular species that are toxic to tissues. In PDT, a great part of the used PS suffers degradation by light (photobleaching) that involves a decrease in the absorption and intensity of fluorescence of the photosensitizer as well as photoproduct formation evidenced by the appearance of a new absorption band. In this study, we investigated the correlation of cytotoxicity and depth of necrosis of Photogem and its photoproducts obtained previously by irradiation at 514 and 630 nm. The cytotoxicity for degraded Photogem decreases with the previous irradiation time of Photogem solution suggesting that the photoproducts of Photogem are less cytotoxics than the original formulation. A transition between the necrosed epithelium and healthy epithelium of normal liver of rats after irradiation at 630 nm was observed with irradiated and nonirradiated PS. It is observed that the depth of necrosis only at irradiation dose of 150 J/cm² in both concentrations is greater for Photogem followed by Photogem degradated previously at 514 and then at 630 nm. The results obtained suggest that the threshold of necrosis values is lower for Photogem followed by its photoproducts formed, suggesting that the photoproducts present a low photodynamic activity. If the photosensitizer degradation happens at the same time as tumor destruction, the drug degradation can be complete before reaching the threshold of necrosis; then it is very important to control the drug concentration and light intensity of irradiation during PDT.     

在磁场作用下水的特性的变化和它的变化机理

我们研究了在磁场作用下水的光学性质和电学性质等的变化,实验发现它们的这些特性和未受磁场作用的水有重大改变特别是在红外光谱和拉曼光谱中的变化更加明显,这种现象就称为水的磁化。我们从水的中红外光谱得知在3000~3800 cm-1的范围内有奇特的六个峰值存在,从水分子结构和红外光谱的特性出发了解到它们分别代表了自由水分子的OH键的对称与反对称的振动,众多水分子通过氢键连接而成的线性链和环形链的OH键的对称与反对称振动,于是从这个实验我们看到了在这个水中存在有众多水分子结合成的环形氢键链的存在。我们用水分子的极化特性,一阶相变的特性和实验进一步证实了这些环形链的客观存在,根据质子或氢离子在氢键系统中传递理论得知在磁场的罗仑兹力作用下处于水中环形氢键链中质子能够进行传导产生环形电流.这些环形电流象一个分子电流或是个小磁体,它们能彼此相互作用或与外加磁场相互作用,从而改变了水分子的分布和结构状态,导致了水的一些特性的变化,这就是水的磁化的分子机理,我们用这个机理解释了我们从实验中所发现的磁处理过的水的特性如饱和效应和记忆效应等,因此这是非常有趣的实验和现象.     

Application of new methods of interpretation of meteor observations at the Institute of Astrophysics of Tajikistan

New methods of interpretation of meteor observations were developed and published in [1?C9]. The interpretation of ground-based observations of meteors and bolides available today in the scientific literature all over the world suffers from serious contradictions. Observers use the so-called photometric approach for determination of extra-atmospheric masses of meteoric bodies. This approach is based on the formula proposed in 1933 [10] and very simple ideas of how to describe the interaction between the atmospheric air and the surface of a meteoric body. These ideas are provisionally suitable to describe the flow around a body in a free molecular regime. Subsequently, the photometric approach was applied to all the meteor events including bolides. The main effort aimed to elaborate the approach included a choice of new formulas for the radiative efficiency.     

Some aspects of the kinetics of formation of triatomic halogenides of rare gases

The formation of triatomic excimer molecules Rg₂X and Rg’RgX by VUV excitation of mixtures of halogens with rare gases is discussed. The remarkable simplicity of the electronic structure and kinetics of these molecules offers interesting possibilities for studying the role of different collisional processes in recombination in the high-and low-pressure limits.     

Model of stochastization of the oscillatory regime of superradiance

Based on the analysis of the experimental data on the observation of the fluorescence and superradiance of praseodymium ions in a matrix of lanthanum trifluoride, a model of superradiance of three-level radiators with two close upper levels is developed in the mean-field approximation and studied. The uppermost level is coherently pumped by an ultrashort pulse of electromagnetic field, after which the excitation is transferred to the close energy level, from which the superradiance transition occurs to the lower level. In limiting cases, the considered model is reduced to the known models of superradiance and describes the ordinary regimes of monopulse and multipulse (oscillatory) superradiance. However, in a certain region of parameters, the model under discussion describes such a multipulse superradiance signal in which electromagnetic field spikes composing it follow in time with random intervals and amplitudes, so that the regime of regular chaotic dynamics is demonstrated in a single superradiance signal. In a certain time interval, the proposed model can be described by the Lorenz equations with the parameters corresponding to the chaotic dynamics of spikes composing the superradiance signal. The presented results of the numerical simulation of the model equations qualitatively correspond to the picture of stochastic pulsations observed experimentally.     

Statistics of partitions of the kinetic energy of small nanoclusters

In Aquilanti, Lombardi, and Sevryuk, J. Chem. Phys. 2004, V. 121, No. 12, P. 5579 and Sevryuk, Lombardi, and Aquilanti, Phys. Rev. A. 2005, V. 72, No. 3, P. 033201, we defined several partitions of the total kinetic energy of a system of classical particles into terms corresponding to various motion modes. In this work, we study the statistics of these terms for clusters with the number of particles N from 3 to 100 (at randomly selected particle coordinates and velocities). Some new kinetic energy components are defined and studied. Two limiting situations are considered, those of particles of equal masses and particles whose masses vary randomly. With equal masses, the mean values of almost all cluster kinetic energy components are expressed in terms of N with the use of very simple equations.     

Analysis of temperature dependence of thermal pressure of solids

Various models for determination of the temperature dependence of thermal pressure are critically examined in the light of experimental data. We have considered Mg₂SiO₄, Olivine, MgAl₂O₄, Pyrope rich garnet, Fe₂SiO₄, Grossular garnet, MnO, NaCl and KCl. The superiority of one model over others is discussed. The model is extended to study the compression behaviour at different temperatures, and the combined effect of pressure and temperature on thermal pressure of San Carlo Olivine. A good agreement obtained between theory and experiment demonstrates the validity of the present approach.     

A theoretical study of the effect of disorder of the transition dipole moments of molecules on the shape of optical bands of molecular aggregates

Aggregates with substitutional disorder, in which molecules of different types have different transition dipole moments, are considered. The relations between the absorption spectra of aggregates with disordered and nondisordered transition dipole moments are obtained for two limiting cases: (1) the case when there is no statistical correlation between the transition energies and transition dipole moments of the molecules and (2) the case of total correlation, when the transition energies and transition dipole moments are strictly related to each other. For aggregates that are characterized by substitutional disorder along with diagonal disorder, an effective method of calculation of the optical bands is developed. Numerical calculations of the absorption bands of aggregates consisting of molecules of two types are carried out at different values of the parameters.     

Modeling of the interrelation of mechanical and electrical parameters of the surface of solids

A mathematical model for the determination of physical constants in equations of state at the interface between a metal and an inert gas medium has been developed in terms of the surface physics and thermodynamics of nonequilibrium processes with due regard for internal stresses induced by a redistribution of conduction electrons. Physical characteristics of a surface layer, in particular, at the copper-inert gas medium interface and the silicon-inert gas medium interface, have been determined using experimental values of surface tensions and energies for contacting media.     

Temperature dependence of self-reversal of magnetization of nickel

The temperature dependence of the self-reversal of magnetization of polycrystalline nickel wire at temperatures from room temperature to the Curie point is examined and interpreted. The critical field for self-reversal and the reversed magnetization decrease steadily towards the Curie point and are affected by tension and the prehistory of the specimen.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 52–55, January, 1973.