Effect of the dependence of the specular reflectance on the angle of incidence of electrons on the impedance

We obtain the solution to the problem of the skin effect in a metal with specular-diffusion boundary conditions for arbitrary values of the anomaly parameter in the form of the Neumann series. For this purpose, we develop a method based on the idea of representation of not only the boundary condition imposed on the field (as is conventionally done), but also the boundary condition imposed on the distribution function, in the form of a source. The specular reflectance is an arbitrary function of the angle of incidence of electrons on the metal surface.     

光合细菌的抗氧化作用机理探讨

活性光合细菌1号株的培养离心得到菌体和上清液两个组分。这两种组分在两个重要离体系统中{牛血清蛋白－亚麻油酸 －Fe^2 (Ⅰ系统）和脑组织匀浆－Fe^2 (Ⅱ系统）}具有明显抗指质过氧化作用。止清液作用较弱,在两个系统中其抑制作用为10.2%-13.4%。而在Ⅰ系统中菌体浓度为5mg/L时,抑制率为56.9%,在Ⅱ系统中菌体浓度仅5ug/L时,抑制率就达到74.1%。进一步研究表明：在碱性条件下,连苯三酚会产生超氧队离子,并由它引发连锁反应而发生氧化。自由氧化进程曲线的斜率K值代表了它自氧化速率的大小。在空白对照情况下K1值为1.33,而添加菌体悬液达250mg/L,K5值下降至0.47,说明光合细菌有显著抑制连苯三酚自氧化作用,其原因是光合细菌中有效成分对超氧阴离子有很好的猝灭作用。     

基于四叉树的光学小波滤波器轴心定位的研究

精度问题制约了光学小波变换的广泛应用。若要扩展其应用领域,必须提高变换精度。在二维光学小波变换4f系统中,小波滤波器轴心的精确定位至关重要。提出了一种基于四叉树搜索方法的光学小波滤波器轴心定位方法。所用的加载滤波器载体为空间光调制器(SLM),定位精度可达到SLM的一个像素大小。为加快搜索速度,提出了一种基于四灰度级并行处理的改进方法。     

耦合孔对微波腔的影响研究

从Maxwell方程出发,将微波腔中的实际微波场按其本征模式展开,进行微波腔的工作特性(如工作频率、场分布等)的研究.在具体处理过程中,根据复杂结构微波腔的具体边界,将微波腔分成规则形状微波腔和非规则(含耦合孔)部分,建立实际微波腔模式同规则形状微波腔模式之间的场耦合方程,从而确定耦合孔对微波腔模式的影响,并对开耦合孔的圆柱腔进行了相应的理论和模拟研究. 关键词： 微波腔 模式 场耦合 圆柱微波腔     

Effect of the structure of a complex network on the properties of the dynamical processes on it

The effect of the structure of a complex network on the properties of an avalanche dynamical process on it has been studied. It has been found that such a structural characteristic of the network as the degree of its assortativity (disassortativity), which is numerically expressed by the assortativity coefficient r, is a control parameter determining the properties of the dynamical process on the network.     

Effect of the structure of a complex network on the properties of the dynamical processes on it

JETP Letters - The effect of the structure of a complex network on the properties of an avalanche dynamical process on it has been studied. It has been found that such a structural characteristic...     

工作压力对热声驱动阻容负载性能影响的实验研究

进行了热声发动机驱动阻容负载的实验研究;讨论了工作压力对热声驱动阻容负载性能的影响。随着平均工作压力的增大,负载入口处压力振幅和输出的声功率都明显增大,同时板叠热端温度有较大幅度下降,有利于低品位热源的利用和提高系统相对卡诺效率。     

Influence of the Elastic Base of a Basin on the Propagation of Waves on the Water Surface

A layer of an ideal liquid located on an elastic half-space (with a flat unperturbed boundary) is considered in the linear approximation. At the zero time moment, a localized perturbation of the displacement vector occurs in the elastic half-space, and this perturbation, after some time, leads to a modification (perturbation) of the interface between the water and the crust, which, in turn, leads to a localized perturbation on the surface of the liquid and to the occurrence of surface waves. We are interested in the following question: to what extent does getting rid of the stiffness of the bottom and replacing it by an elastic base influence the speed of propagation of the front of the long wave and its profile under the assumption that the initial perturbation is given immediately on the free surface of the liquid?     

Modelling of the Effect of the Sheared Poloidal Flow on the Electrostatic Turbulence on the CASTOR Tokamak

Electrostatic drift turbulence of the edge plasma in the CASTOR tokamak is studied numerically by using the Hasegawa-Wakatani equations. The fluctuations of plasma density and potential as well as the corresponding fluctuation-induced particle flux are calculated for regimes with various plasma poloidal flows. Results of numerical simulations are in a reasonable agreement with experimental results.     

Environmental influence on the formation of α-FeOOH on the surface of weathering steel

A CEMS and XMS study of the surface oxidation of weathering steel, ASTM A242 Type 1, has shown that after exposure times of 5 1/2 years in a marine or industrial environment, the steel has not yet reached a stage at which the surface is fully protecting the substrate from further corrosion. The formation of α-FeOOH, an intermediate stage of protection, occurs mainly in the form of small particles, the properties of which exhibit an appreciable amount of superparamagnetic relaxation. For the steel exposed to a more moist marine environment, α-FeOOH exists only in the form of small particles. However for the steel exposed to a much dryer and corrosive industrial environment, more α-FeOOH is present. The formation of bulk α-FeOOH is more complete. The temperature dependence of the superparamagnetic hyperfine field and also the field distributions indicate that, in a marine environment, the clusters of α-FeOOH are both smaller in size and have a larger distribution of particle size. The XMS results indicate that α-FeOOH is present below a layer of γ-FeOOH and ferrihydrite which are generally accepted to constitute the early oxidation phases observed on steels.     

Investigation of the effect of heating on the formation of carbon films on diagnostic mirrors

The effect of heating on the growth rate of hydrocarbon films and reflection spectra of metal mirrors with the use of a plasmatron dc current source with a graphite cathode was investigated.     

基于B样条迭代法的激光光条噪声去除技术研究

在基于线结构光的视觉测量系统中,激光光条中心的提取精度是影响系统最后精度的关键因素。目前常用的光条中心提取方法都没有去除光条上的干扰噪声,在分析现有方法的基础上提出了一种利用B样条迭代去除光条噪声的方法。以光条上的点作为控制顶点拟合B样条曲线,在同一位置下用B样条曲线上的点取代噪声点,这样反复修改噪声点的位置使其逐渐逼近实际曲线,从而达到去除噪声的目的。利用重心法提取去噪后光条的中心,着重分析了参与运算的像素的取值范围。通过对比实验证明该方法的提取精度远高于其它方法,从而验证了去除噪声的有效性。     

银纳米颗粒对胆固醇荧光的增强效用研究

在传统荧光光谱技术的基础上,结合金属纳米颗粒的增强荧光技术,探索提高荧光光谱技术检测人全血溶液中胆固醇含量的精度和分辨率的方法。实验研究方面,采用波长为407 nm的激光作为激发光,照射加入一定量银纳米颗粒作为荧光增强剂的人全血溶液,研究了银纳米颗粒对人全血溶液在可见光波段的荧光增强作用。结果表明,胶体状态的银纳米颗粒可以显著增强低浓度的人全血溶液荧光光谱的强度,且不同位置荧光发射峰的荧光增强效率随银胶加入量的增加均呈现先增后减的趋势,但不同峰位置的最强增强效率对应的银胶加入量不同。理论分析方面,根据实验结果及胆固醇分子和银纳米颗粒在溶液中的分布情况,建立了分子间距模型,并根据模型计算得出胆固醇分子和银纳米粒子之间的最佳增强荧光效果间距在12.19～25 nm范围内,这个结果和其他文献中的理论值吻合较好。综上所述,使用银纳米颗粒可实现全血溶液荧光的增强,研究结果为提高检测血液中多种物质的灵敏度和精度提供了有价值的参考作用。     

Effect of sulfide pollution on the stability of the protective film of benzotriazole on copper

Benzotriazole (BTAH) is an excellent inhibitor for the corrosion of copper and many of its alloys in unpolluted media. Protection is attributed to the formation of a film of Cu(I)BTA. Injection of sulfide ions into a benzotriazole inhibited salt water damages the protective Cu(I)BTA film very rapidly, increases the corrosion rate and leads to the formation of copper sulfide. This effect is quite marked at a sulfide concentration as low as 10⁻⁵ M (about 0.3 ppm sulfur) in the presence of 10⁻² M BTAH, which is 1000-fold greater than that of the sulfide ion. The intensity of sulfide attack increases with its concentration.Prolonged pre-passivation of copper in the BTAH protected medium even at high concentration does not markedly improve the resistance of the protective film to sulfide attack. This finding is contrary to a well-documented phenomenon in unpolluted media where the inhibiting efficiency of BTAH increases with the time of immersion and the concentration of the inhibitor. X-ray photoelectron spectroscopy (XPS) reveals the presence of both sulfide and BTAH on the corroded surface indicating that sulfide attack is localized.     

Effect of the link lifetime in a dynamical lattice on the properties of the avalanche processes on it

The properties of the avalanche processes that develop on a dynamical lattice, the structure of links in which changes due to a specific characteristic of each lattice node, namely, its “activity,” which determines the probability of connection of a certain node with neighboring nodes in one step of lattice evolution. The statistics of the sizes of the avalanches appearing in the lattice system is studied as a function of the node activity and the link lifetime (the lifetime of the links formed in the system). It is analytically and numerically shows that the type of avalanche dynamics in the system changes as a function of these parameters. The following three regimes can take place in the system: (1) avalanches of any sizes, from small to catastrophic, can appear, which is reflected in the power-law behavior of the probability density function of the appearance of avalanches of certain sizes; (2) avalanches of a certain average size mainly appear in the system, and the probability density is close to that of a normal distribution; and (3) transient regime, where the probability density function of the appearance of avalanches of certain sizes is close to an exponential function. These results open up the possibilities of controlling the behavior of a complex system; in particular, they can be used to prevent catastrophic avalanches by changing the link lifetime and the average node activity.     

Influence of cosmic rays on biomarkers on the mars

Detection of the organic substance on the Mars is one of the main targets of the current and future Martian landing missions. In this study, we calculated the ionization of the Martian soil by solar and Galactic cosmic rays at its various depths. It is shown that complex organic molecules (biomarkers) with a mass more than 300 a.m.u. at a depth of ≤10 cm degrade for a time less than one milliard years.     

光谱法研究变性剂对苦荞麦蛋白质构象的影响

采用紫外差示光谱和荧光光谱研究了不同浓度的乙醇溶液和盐酸胍溶液对苦荞麦蛋白质(TBWSP31)构象变化的影响.研究表明,TBWSP31的色氨酸残基和酪氨酸残基有的位于分子内部,有的暴露于分子表面.乙醇溶液使TBWSP31变性时,仅仅是分子的外层结构发生了变化,分子内部疏水核的变化较小,高浓度的盐酸胍使位于TBWSP31...     

Electrostatic microtrap on the surface of the chip

As is well known in atomic optics, the nonadiabatic transitions induce the loss of atoms trapped in a magnetic well which seriously affects the formation of the Bose-Einstein condensates. Electrostatic traps have widespread applications in molecular optics. While, for most existing electrostatic traps, the electric field strength in the trap center is nearly zero which may cause the nonadiabatic transitions. Especially for a chip-based microtrap, ingenious design is need to overcome this problem. In the paper, we propose a novel electrostatic microtrap composed of four arc-shaped electrodes. The influences of the voltages and the geometrical parameters of the electrodes on the electric field strength as well as the height of the potential well are studied. The distributions of electrostatic field are numerically calculated. We firstly simulate the trajectory of one molecule in the processes of loading and trapping. After that, we simulate the movements of a large number of molecules using the method of Monte Carlo. Then we calculate the temperature of trapped cold molecules. After that, we analyze the impacts of voltages and the geometrical parameters on the efficiency of our microtrap. At last, we show that our scheme can evolve into electrostatic microtrap arrays which should be a powerful tool for a variety of basic research and applications.     

A Note on the Second Order Universality at the Edge of Coulomb Gases on the Plane

We consider in this note a class of two-dimensional determinantal Coulomb gases confined by a radial external field. As the number of particles tends to infinity, their empirical distribution tends to a probability measure supported in a centered ring of the complex plane. A quadratic confinement corresponds to the complex Ginibre Ensemble. In this case, it is also already known that the asymptotic fluctuation of the radial edge follows a Gumbel law. We establish in this note the universality of this edge behavior, beyond the quadratic case. The approach, inspired by earlier works of Kostlan and Rider, boils down to identities in law and to an instance of the Laplace method.