Co(S1-xSex)2系统中的铁磁量子相变

针对Co(S_1-xSe_x)₂系统在x=0.11附近发生的铁磁金属到顺磁金属相变,制备了一系列不同Se替代浓度的多晶样品.通过对其结构和电阻率-温度ρ(T)关系的系统观测,结果发现,样品铁磁相变温度T_C随着Se替代浓度x值的增加,以(1-x)^1/2关系单调下降,其二级铁磁相变转变为一级相变 关键词： 量子相变 自旋量子涨落 1-xSe_x)₂')" href="#">Co(S_1-xSe_x)₂     

An Alternating-Current Voltage Modulated Thermal Probe Technique for Local Seebeck Coefficient Characterization

Nanostructured and nanocomposite thermoelec- tric materials have recently attracted a great deal of attention due to the optimization of thermal and electrical transports for high thermoelectric performance The initial ideas for the applica- tions of nano-structures in thermoelectric materials are that the lattice thermal conductivity can be de- pressed by the scattering of nano-particles or nano- boundaries as well as the enhanced electron density of states at the Fermi level. The latter is expected to enhance Seebeck coefficients due to the fact that the low energy carriers can be filtered by nano-sized grain boundaries. Lowered thermal conductivity and enhanced thermoelectric figure of merit have been ob- served in lots of bulk materials with nanostructures or nano-impurities. However, the thermal and electrical transports in these nano-materials are usually mea- sured by normal commercial systems, in which only the statistical values of the transports are obtained. The characterization of local thermoelectric parame- ters still remains a challenging task at the submicro, even nanometer level as a powerful tool for Scanning probe microscopy nanostructure imaging and local properties characterization, has become a promis- ing technique for measuring local thermal and electri- cal properties, like scanning tunneling microscopy, scanning thermal microscopy, and scanning Joule expansion microscopy. Recent work has demon- strated simultaneously determined the thermal con- ductivity and Seebeek coefficient of Bi2Se3 thin film by a microprobe technique.     

古典概率模型中样本空间的选择

古典概型是高中数学概率学习的核心．在古典概率的计算过程中，样本空间的选择是关键一环，主要表现在“能否正确选择样本空间”和“能否选择较小样本空间”两方面．在理解题意的过程中是否注重这两方面的思考，将决定解题的成功与高效．本文举例说明，供读者参考。     

利用激光直接驱动冲击波进行压强高为1．6TPa铜的雨贡纽数据测量

2003年度在“神光”Ⅱ上进行了两轮倍频激光直接驱动状态方程实验，取得了较大进展，获得了不错的结果。首次完成了倍频(2w)激光束均匀化系统的设计和研制，在实验中得到应用，结果表明，该系统在测试要求下，基本能满足激光状态方程实验的要求，但在高精度测量测试条件下，尚难获得高质量的平面冲击波，需对列阵透镜束匀滑系统作进一步的优化设计研究，以满足更高精度状态方程实验测量的要求。在倍频激光直接驱动状态方程实验中，利用现有的条纹相机进行了高时间分辨的冲击波信号记录，     

电位滴定法测定氟石中硫酸钡含量的样品预处理方法研究

开发了测定氟石中硫酸钡含量的样品预处理方法。设计了含有适量的ＳＯ＾２－４，Ｆ＾－和ＣＯ＾２－３的饱和硫酸钡溶液作为样品预处理溶液。应用溶度积原理将与硫酸钡共存的有干扰的钙，锶，铅的硫酸盐转化成严难溶的氟化物和碳酸盐除去，硫酸钡中硫还原成Ｈ２Ｓ电位滴定。     

Silica-Based 64-Channel Arrayed Waveguide Gratings with Double Functions

Silica-based 64-channel arrayed waveguide gratings （AWGs） with double functions and 0.4 nm （50 GHz） channel spacing have been designed and fabricated. On the same component, Gauss and flat-top output response spectra are obtained simultaneously. The test results show that when the insertion loss ranges from 3.5dB to 6.4dB, the crosstalk is better than -34dB, the 1 dB bandwidth is 0.12nm, the 3dB bandwidth is 0.218nm, and the polarization-dependent loss （PDL） is less than 0.5 dB for Gauss response. When the insertion loss ranges from 5.8dB to 7.8dB, the crosstalk is better than -30dB, the 1 dB bandwidth is 0.24nm, the 3dB bandwidth is 0.33nm, and the PDL is less than 0.2dB for fiat-top response.     

基于敏感内容的图像检索技术

利用基于内容的图像分析与检索技术能够自动识别包含国家机密的图像，对其进行自动处理或过滤，就能够有效的提高系统的运行效率，增强国防信息的安全等级。任意给定两幅图像i和j，在此假设i为查询目标，j为图像库中任意一幅图像。设任意图像的某个内容可用特征向量F11，F12,…,F1N表示。用欧拉距离对不同图像间内容的相似度进行测量D(i，j)=(Fi-Fj)^2，Fi,Fi为第i和第j幅图像的相对应特征数据。对多特征联合检测，引入权数据w，     

柔性透明导电薄膜(ITO)简介

柔性透明导电薄膜 (ＩＴＯ)是一种新型半导体材料 ,目前主要依赖进口 ,但价格昴贵 ,国内生产厂家较少。深圳市北庆薄膜技术有限公司经多年研制、开发 ,形成了年产 50 ,0 0 0ｍ2 透明导电膜 (ＩＴＯ)的能力 ,产品质量完全可以替代同类进口产品。北庆公司所生产的导电膜具有重量轻、体薄、导电性能好、附着力强、透过率高、耐冲击、可弯曲、可任意冲裁加工等优点。该产品可以用作光电子器件的透明电极、电磁静电屏蔽的透明视窗、观察窗以及防霜加热膜 ,还可以用在特殊要求的透明器件上作防静电包装。在某些方面它可以取代导电玻璃 ,并且可以开…