合金材料激光表面重熔快速凝固过程数值模拟

根据合金固液盯变多区域性特点，用数值方法求解了适用于多区域相变的单相统一控制方程组，并据此对１Ｃｒ１８ＮｉｏＴｉ不锈钢激光表面重熔熔池的快速凝固过程进行了理论分析。     

X射线荧光光谱分析中基体效应的数学校正方法新探

用开发的ＴＢＨＸＲＦ基本参数法程序计算了复杂样品的基体效应。提出一个修正多元体系基体效应的校正数学模型和计算影响系数α及β，导出的校正模式及影响系数的物理意义清楚、明确。用该法分析了不锈钢样品获得良好的结果。还指出在某些情况中，三次荧光的影响不能忽略，从对比实验中得出结论，对Ｎｉ浓度高的钢铁样品在分析Ｃｒ时，必须考虑Ｎｉ、Ｆｅ对ＣｒＫα的三次荧光效应影响。     

用通用X—射线荧光光谱仪进行铬的形态分析

本文用通用Ｘ－射线荧光光谱仪和一套自行设计的谱分析程序对一些含铬物质的Ｋβ发射谱进行了形态分析。谱强度数据经过处理后，得到了谱形和谱峰参数（峰位、峰高、半峰宽和非对称因子等）和形态之间的一些定性、定量关系。并利用所得出的规律分析了化学镀铬层和不锈钢中的铬元素的形态分布，分析结果的相对误差在１０％以内。     

取消次级中子源对压水堆氚源项的影响分析

在压水堆正常运行期间，氚贡献了压水堆液相流出物总活度的95%以上，是反应堆设计和运行中的关键放射性核素之一。通过对美国在运的8台堆芯设计非常相似的机组2000至2019年期间氚排放数据进行较为深度的数据清洗和分析研究，得出采用不锈钢包壳的Sb-Be次级中子源的氚释放是压水堆机组氚源项的重要来源之一，统计机组中次级中子源产氚贡献平均为7.5 TBq·a^-1，结合理论计算，符合当前包壳材料发展和运行管理水平下的渗透比例10%～20%。取消次级中子源约可以降低20%的因氚排放造成的公众剂量，还可以降低氚源项对厂址规划机组数量的制约。此外，研究还发现，氚排放量的显著波动受到液态集中排放的显著影响，特别是在美国压水堆大修之前或期间，这将有助于优化未来机组放射性排放管理。     

强流脉冲离子束辐照对不锈钢耐腐蚀性能的影响

 利用强流脉冲离子束（HIPIB）对316L不锈钢进行了表面辐照处理，研究了HIPIB辐照对其在0.5mol/L H2SO4溶液中电化学腐蚀性能的影响。极化曲线测量结果表明，HIPIB辐照能够显著提高316L的抗腐蚀性能，自腐蚀电流对辐照次数的依赖性与自腐蚀电位相比明显较强。采用扫描电子显微镜（SEM）、X射线衍射（XRD）和电子探针（EPMA）分析辐照后试样表面形貌、表面层相结构和元素分布的变化。结果表明：HIPIB辐照使试样表面光滑化，表面层产生择优取向，且发生了杂质元素的选择性烧蚀，是316L不锈钢耐电化学腐蚀性能得以提高的主要原因。     

直读光谱仪分析不锈钢中氮

直读光谱分析不锈钢中氮含量 ,确定了氮的光谱分析线、最佳分析条件 ,分析样品的制备要求 ,共存元素的影响和氮校准曲线的拟合情况。本法具有良好的准确度和精密度 ,氮元素的分析检出限为6 .3μg/ g,检测范围为 0 .0 0 1%— 0 .4 2 %。     

超声探伤信号的人工神经网络识别

粗晶奥氏体不锈钢的超声探伤受到能否有效区分有用信号与背影噪声的限制，目前人们大多倾向使用频率分隔来提高缺陷回波比例。本文则介绍一种用傅里叶变换作特征提取，用前馈网络自动识别奥氏体钢中缺陷信号的方法。在作者的实验中，这种方法的正确识别率达到９０％。     

聚氨酯泡沫塑料磁控溅射镀膜工艺

机械加工后的聚氨酯泡沫塑料，由于破坏了模塑成型的外表面膜层，材料本身多孔隙暴露在空气中，极易受潮、变形，孔隙吸附的气体对真空度有严格要求的镀膜造成极大困难，材质疏松不利于膜层结合，其低熔点的性质也使镀膜工艺的选择受到限制。采用合适的前处理技术和磁控溅射镀膜参数，可以在保证制造精度的前提下镀得一定厚度的不锈钢膜层，为该类产品提供有效的防护。     

氢在不锈钢及氧化铬膜复合体中的稳态渗透实验

本文介绍氢在ＨＲ－１不锈钢基体及镀有氧化铬膜的复合材料中的行为研究，包括基体的准备；膜的制备；用不同手段从不同角度对膜进行的分析测试；膜与基体之间的平均结合力测定；用不锈钢材料构成的高温低压渗透回路的建造、调试、密封性能校准；纯ＨＲ－１基体材料中的氢渗透规律研究；有膜复合材料中氢的稳态迁移过程的表现规律实验结果。它们与国外类似的实验符合得较好；膜的分析测试结果反过来对制膜工艺提供了很有用的反馈信息，氢渗透回路的性能通过了有关专家鉴定，主要技术指标已达到国际同类设备的先进水平。为下阶段更广泛深入的研究奠定了良好的基础。     

不锈钢管道低温溅射镀TiN薄膜技术

 设计了一套适用于加速器细长管道真空室的低温溅射镀TiN薄膜装置。利用该装置，对86 mm×2 000 mm的不锈钢管道真空室进行溅射镀TiN膜实验，并对镀膜实验结果进行分析，得到了适用于加速器管道真空室内壁溅射镀TiN膜的表面处理参数。样品测试结果表明：在压强为80～90 Pa、基体温度为160~180 ℃的镀膜参数下，不锈钢管道内壁获得的TiN薄膜最佳，薄膜沉积速率为0.145 nm/s。镀膜后真空室的二次电子产额明显降低。     

Thin and thick diffraction gratings: Thin matrix decomposition method

A brief review of the properties of transmission diffraction gratings is presented. Two types of gratings will be analyzed: thin and volume gratings explaining how the efficiency of the different orders that propagate inside the gratings can be calculated in both cases. For thin diffraction gratings the so-called amplitude transmittance method is applied in order to get the amplitude of the different orders, whereas in the case of volume gratings more complex methods are needed, such as Coupled Wave or modal theories. We will comment on the thin matrix decomposition method (TMDM), firstly proposed by Alferness, which gives a very intuitive approach and connects the properties of thin gratings to the properties of volume ones. The thin matrix decomposition method consists in dividing the volume grating in a number of thin gratings and applying the amplitude transmittance method to each thin grating. In this way the output of a grating will be considered as the input of the next and any individual grating can be treated by the amplitude transmittance method. The novelty of this work is that a comparison is made between the analytical expressions obtained by Alferness using the TMDM with the numerical results obtained using the coupled wave (CW) and rigorous coupled wave (RCW) theories for the efficiencies of the zero, first and second order when a plane wave incides onto a sinusoidal diffracion grating at the second on-Bragg replay angular condition.     

Thin film thickness step gauge

The Blodgett-Langmuir technique is used to deposit multilayer films of barium stearate on EDF glass. The thickness of the film varies in steps of 10 monolayers, and the thickness of each monolayer is about 25 Å. When viewed in white light at near normal incidence vivid interference colours are seen in reflection, with good contrast between adjacent steps. The reliability of the step gauge is tested for dielectric films of MgF₂.     

薄环形等离子体介质切伦柯夫脉塞

 理论分析了无限大引导磁场情况下的薄环形等离子体介质切伦柯夫脉塞。得出了通入相对论电子注时行列式形式的热腔色散方程,并求出了波增长率。针对不同等离子体密度下,对色散方程以及波增长率进行数值计算和模拟验证。研究发现与电子注作用的主要模式为低频等离子体模式中的前两个模式,随着等离子体密度的升高,脉塞中心工作频率升高、增益变大、带宽明显变宽,由模拟结果可以看出:等离子体频率为4.5×10¹⁹ m^-3时对应着最大的输出功率为80 MW,效率为19.75%,频率为15.55 GHz,继续增大等离子体密度虽然可以使输出频率进一步提高,但是同时会使输出功率迅速下降。     

Thin sol-gel bismuth silicate films

The sol-gel method is used to obtain thin films with the composition Bi₁₂SiO₂₀. The characteristic features of the technology for obtaining the films are presented. Diffractometry confirmed that the films possess γ-Bi₂O₃-type structure. The transmission spectra of the films were investigated. The spectral dependence of the absorption coefficient of the films matches well with the spectra determined using bulk Bi₁₂SiO₂₀ crystals. Fiz. Tverd. Tela (St. Petersburg) 41, 1003–1005 (June 1999)     

Thin oxide films on germanium

The optical constants, i.e. the refractive index and thickness, were determined for thin oxide films which were produced by heating single-crystal samples of germanium to temperatures ranging from 450° C to 600° C. The ellipsometric method was used to determine the thicknesses and the refractive indices of the films. The paper is dedicated to the memory of Dr. A. Vaíek, Professor of the J. E. Purkyn University in Brno, who died on Nevember 16, 1966.     

Critical Dynamics in Thin Films

Critical dynamics in film geometry is analyzed within the field-theoretical approach. In particular we consider the case of purely relaxational dynamics (Model A) and Dirichlet boundary conditions, corresponding to the so-called ordinary surface universality class on both confining boundaries. The general scaling properties for the linear response and correlation functions and for dynamic Casimir forces are discussed. Within the Gaussian approximation we determine the analytic expressions for the associated universal scaling functions and study quantitatively in detail their qualitative features as well as their various limiting behaviors close to the bulk critical point. In addition we consider the effects of time-dependent fields on the fluctuation-induced dynamic Casimir force and determine analytically the corresponding universal scaling functions and their asymptotic behaviors for two specific instances of instantaneous perturbations. The universal aspects of nonlinear relaxation from an initially ordered state are also discussed emphasizing the different crossovers occurring during this evolution. The model considered is relevant to the critical dynamics of actual uniaxial ferromagnetic films with symmetry-preserving conditions at the confining surfaces and for Monte Carlo simulations of spin system with Glauber dynamics and free boundary conditions.     

Applications of Surface Polaritons for Vibrational Spectroscopic Studies of Thin and Very Thin Films

Abstract

Studies of the surface state of solids, their detection, and studies of the surface transition layers including oxide films, physi-, and chemisorbed monomolecular films, their transformations at phase transitions and their chemical reactions have stimulated the development of a series of new methods. The nondestructive character of optical methods, their sensitivity to molecular structure and to the nature of chemical bonding, makes them very attractive for use.     

Thin layer dye laser amplifier

A simple method to amplify laser radiation is proposed: the divergence is nearly diffraction limited and the intensity distribution profile is gaussian (independent of the spatial parameters of the input signal). The amplification of the laser radiation is achieved using the quasi-waveguide laser of a solution of rhodamin 6G with a concentration of 10^-2 mol/$\text{l}$. A hundred fold intensity amplification with a divergence of 6 × 10^-4 rad is achieved, the latter being only 1.4 times more than the diffraction limited divergence of the system.     

超分子有机薄膜

利用超分子有机薄膜技术能制成新的传感分子电子器件、光学器件和生物分子器件等，受到跨学科高技术研究领域的重视。本文描述了超分子有机薄膜的制备方法以及在各应用领域的研究状况。重点介绍了我们研究组在近20年工作中，利用LB膜技术，在光电器件、气体传感技术和光学非线性，特别是在生物传感技术方面的研究成果。按照生物体系提供的信息，模拟合成功能分子，建造有组织的分子组装体，以便用来研究依赖于分子排列的生物物理化学效应。     

Thin cylindrical shells in general relativity

The sources of static cylindrically symmetric fields in the form of thin cylindrical shells are studied. The results are compared (in the case of the thin shell consisting of orbiting particles with the result of Raychaudhuri and Som). A special solution is also found, represented by a collapsing shell which is the source of the static field.