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1.
刘云圻  刘升高 《物理》1996,25(7):395-403
有机光电磁功能材料是新一代材料。文章简要介绍了有机半导体、光导体、光致变色与电致变色材料、有机非线性光学材料、有机导体、超导体、导电高分子,以及有机铁磁材料和有机分子电子器件。  相似文献   

2.
The investigation of the radiation resistance of Group III–V semiconductor materials is an important and urgent problem. Magnetic sensors based on radiation resistant semiconductor materials are widely used in magnetomeasuring systems of thermonuclear industrial and experimental reactors. The basic approaches to the study of semiconductor materials under conditions of neutron irradiation and the results of some experiments on testing indium-containing semiconductor materials InSb, InAs, and their alloys InAs x Sb1 ? x are presented. The presented experience of the development of equipment for on-line testing of materials and magnetic diagnostic sensors under radiation conditions can be used for testing a wide range of materials under conditions close to those of the ITER and other thermonuclear reactors.  相似文献   

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In recent years, spatial self-phase modulation (SSPM) with two-dimensional (2D) materials has attracted the attention of many researchers as an emerging and ubiquitous nonlinear optical effect. In this review, the state of the art of 2D material-based SSPM is summarized. SSPM measures or tunes the nonlinearity of 2D materials, and it is also an effective approach to study the band structure of 2D materials. Several modified forms of SSPM, such as high-order, white-light-excited, vector field excited, and optically nonlinearly enhanced SSPM are also presented. Subsequently, the physical origin of the SSPM formation mechanism is compared and analyzed. Furthermore, the applications of SSPM with 2D materials, including passive photonic devices, generation of Bessel beams, and identifying the mode of the orbital angular momentum, are listed. Finally, several urgent problems of the SSPM with 2D materials, potential applications, and prospects for future development are presented.  相似文献   

5.
In this article, studies on the magnetoelectric effects of multiferroic materials in high magnetic fields, particularly pulsed magnetic fields, are discussed and results for some representative materials are presented. In the discussions on representative materials, the relationship between the crystallographic symmetry and the linear magnetoelectric effect in Cr2O3 is introduced. Then drastic changes in polarization caused by magnetic transitions are discussed through a case study of manganites with a perovskite-type structure. In addition, high field studies on the magnetoelectric effects in BiFeO3, which is an exceptional multiferroic material, are presented and discussed in the framework of the Landau-Ginzburg theory.  相似文献   

6.
Two attractive methods for materials characterization are applied and discussed: (a) light scattering topography for fast and nondestructive testing of structural perfection, and (b) photoluminescence topography for evaluating the light emission characteristics of photoluminescent materials. Among the examples presented are semiconductor substrates and films of silicon, silicon-on-insulators of different kind, and III–V materials.  相似文献   

7.
The work is dedicated to improvement of efficiency of storage and processing of food raw materials using radiation technologies. International practice of radiation processing of food raw materials is presented and an increase in the consumption of irradiated food products is shown. The prospects of using radiation technologies for the processing of food products in Russia are discussed. The results of studies of radiation effects on various food products and packaging film by γ radiation and accelerated electrons are presented.  相似文献   

8.
Methods are proposed for taking into account intensity losses due to random deviations of composition profiles and due to small-angle scattering effects in amorphous materials and wide-angle scattering effects in polycrystalline materials. Experimental data are presented on the study of polycrystalline-diamond lenses using a synchrotron radiation beam.  相似文献   

9.
光学材料的激光损伤形态研究   总被引:9,自引:0,他引:9       下载免费PDF全文
 提出了破坏形态因子的概念并以高功率连续激光作用下的光学材料的热力学响应为例,通过积分变换的方法给出激光作用期间温度场和应力场的解析形式,继而得到破坏形态因子的表达式及其简化形式,研究破坏形态因子与材料性质、激光参数的关系,从而预言特定的材料在特定的激光作用下的破坏形态。  相似文献   

10.
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We describe the techniques which permit one to measure the electrodynamic response of conductive materials in the millimeter and submillimeter wavelength ranges. Results of studying dielectric spectra of a number of materials whose properties are determined by electron correlations, e.g., superconductors, one-dimensional conductors, and compounds with heavy fermions, are presented.  相似文献   

12.
磁性材料新近进展   总被引:11,自引:0,他引:11  
都有为 《物理》2006,35(9):730-739
磁性材料是应用广泛、品种繁多的一类重要的功能材料,20世纪90年代以后发展十分迅速.稀土-3d过渡族磁性合金材料,如稀土水磁、巨磁致收缩材料、巨磁热效应材料,磁光效应材料等,以及非晶,纳米微晶磁性材料相继问世.1988年巨磁电阻效应的发现已获广泛应用,如读出磁头、传感器以及磁随机存储器等,并发展成为自旋电子学的新学科.文章简要介绍了近年来磁性材料的一些新进展。  相似文献   

13.
Plastic container materials are evaluated for use in macroencapsulation of latent heat storage materials, with special emphasis on fatty acids. Different platics have been tested. With the most promising container material and a mixture of two fatty acids a laboratory model of a storage unit was built; first results of the experiments are presented.  相似文献   

14.
在WGD-8A光栅光谱仪上实现变温荧光特性测量   总被引:1,自引:0,他引:1  
介绍了一种在普通光栅光谱仪上实现材料荧光 温度特性测量的低成本方法,并给出了系统的详尽配置和运用该系统对部分材料荧光温度特性测量的结果.  相似文献   

15.
We have used non-dispersive Fourier-transformspectroscopic techniques to measure the complex indices of refraction of materials between frequencies of 120 and 550 GHz. Results are presented for crystal quartz, crosslinked polystyrene (Rexolite 1422), glass-loaded polytetrafluoroethylene (Duroid 5880) and a nickel ferrite (Trans-Tech 2-111). These results are compared with other data on these materials in this frequency range. The accuracy of these measurements yields a considerable improvement in the near-millimeter-wave characterization of several of these materials. For materials other than crystal quartz, our results are the first measurements of their properties over the entire frequency range studied.  相似文献   

16.
Electronic stopping powers for 0. 05-10 MeV protons in a group of organic materials are systematically calculated. The calculations are based on Ashley's dielectric model, and an evaluation approach of optical energy loss function is incorporated into Ashley's model because no experimental optical data are available for most of the organic materials under consideration. The Barkas-effect correction and Bloch correction are included. The proton stopping powers for the considered organic materials except for mylar in the energy range from 0.05 to 10 MeV are presented for the first time. The results may be useful for studies of various radiation effects in these materials and for space research.  相似文献   

17.
蜂窝结构吸波材料等效电磁参数和吸波特性研究   总被引:7,自引:0,他引:7       下载免费PDF全文
He Yan-Fei  龚荣洲  Wang Xian  赵强 《物理学报》2008,57(8):5261-5266
根据强扰动理论,在长波长近似条件下推导出蜂窝结构吸波材料等效介电常数和等效磁导率的计算公式.电磁参数计算结果表明,蜂窝结构吸波材料等效介电常数和等效磁导率均小于吸收层的介电常数和磁导率,但等效介电常数的降幅更大,从而使等效介电常数更接近于等效磁导率,这正是吸波材料波阻抗匹配设计所需要的.反射率计算结果表明,不同的蜂窝高度,吸收层对应一最优厚度,使蜂窝结构吸波材料的反射率最低.这些结果对于蜂窝结构吸波材料设计具有一定的意义. 关键词: 蜂窝结构吸波材料 等效介电常数 等效磁导率 反射率  相似文献   

18.
It is shown that ellipsometry can be used for nondestructive characterization of defects in surface layers of both single crystal and amorphous materials. Results of ellipsometric measurements on surfaces of materials such as silicon, potassium chloride and glasses, with widely varying preparatory histories are presented and discussed.  相似文献   

19.
Specific features that characterize nanoparticles and which are due to their small size and allow one to enhance the interaction between the electromagnetic radiation and nanostructured materials and to develop the effective protection of man and equipment against harmful uncontrolled radiation are reported. Examples of the development of nanocomposite radar absorbing materials that can be used for protection of man and equipment are presented.  相似文献   

20.
真空室材料二次电子产额特性研究   总被引:2,自引:0,他引:2  
设计了针对加速器真空室材料样品的二次电子产额测试装置. 对测试装置的设计及测试过程进行了详细介绍, 并给出了常见真空室材料的二次电子产额测试结果以及不锈钢材料在经过镀~TiN~薄膜处理前后的测试对比结果, 分析了影响二次电子产额的一些因素, 为真空室的表面处理提供了依据.  相似文献   

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