FABRICATION AND APPLICATION OF NEAR-FIELD OPTICAL FIBRE PROBE

In this paper, the fabrication of a large cone angle near-field optical fibre probe, using the two-step chemical etching method and bent probe, is introduced, and the controlling parameters of the coated Cr－Al film at the probe tip are presented. The scanning electron microscopy images display that the tip diameter of the uncoated large cone angle fibre probe obtained is less than 50nm, the cone angle over 90°, and the diameter of light aperture at the coated probe tip is less than 100nm. The measured results of the optical transmission efficiency for various probe tips show that the uncoated straight optical fibre probe, film-coated straight probe and film-coated bent probe are 3×10^-1, 2×10^-3, and 1×10^-4 times that of the flat fibre probe, respectively. In addition, the force images and near-field optical images of a standard sample are acquired using a large cone angle and film-coated bent probe.     

空间通信电磁传播影响分析

1引言随着航天装备的作用日益重要,各国对制空权的争夺也日益激烈,空间作战依赖于信息,空间电磁环境是空间作战信息依存的主要媒介。在电磁控制权的争夺上是否能够取得优势,很大程度上取决于电子对抗指挥员对电磁环境的准确判断以及对电子对抗作战力量的合理部署及调配。通过对空间通信电磁传播的影响进行分析,构建空间通信的电磁传播模型,从而进一步实现空间战场电磁环境仿真或可视化可为指战人员提供更直观的辅助     

环境管理体系的监控系统——环境管理体系审核和管理评审

剖析了ＩＳＯ１４００１：１９９６标准中与环境管理体系监控系统相关要素的主要内容及其实施要点，并推荐示例以供参考。     

模数转换器的特点与发展趋势

一、概述随着计算机、通信和多媒体技术的飞速发展，全球高新技术领域数字化进程的不断推进，模数转换器（ADC）有了长足进步，出现了许多采用新工艺、新结构的高性能ADC。纵观ADC的发展历程，面临新世纪的ADC正朝着低功耗、高速和高分辨率的方向发展。ADC的分辨率越高（位数越多），需要转换的时间就越长，转换速率就越低。因此ADC的分辨率和转换速率两者总是相互制约的。为满足现代高新技术领域的需求，在发展高速ADC的同时兼顾高分辨率，在发展高分辨ADC的同时兼顾高速。在此基础上，还要考虑功耗、体积、便捷、多功能、与计算…     

Spatial soliton by cascading x~((2)) effect and its self-induced wave-guide in quasi-phase-matched media

The formation of the spatial solitons in the quadratic nonlinearity x(2) media by cascading second harmonic generation (SHG) in quasi-phase-matched (QPM) sample is studied on the basis of nonlinear Schrodinger equation (NLSE). When the solitary wave propagates in the QPM media, it formed optical wave-guides through cascading x(2) effect called self-induced soliton wave-guide. Transverse refractive index distribution of the self-induced soliton wave-guide of fundamental and SHG wave is obtained by cascading process. Analysis of guided-mode of such self-induced soliton wave-guide is first proposed to our knowledge. Be-     

Theoretical Study on Electronic and Charge Transfer Properties of Oligo[8]thiophene and Its Circular,Hooped, and Helical Derivatives

The novel linear, circular, hooped, and helical molecules based on oligo[8]thio- phene were theoretically studied for the applications of charge transfer devices. To investigate the influence of topology for oligo[8]thiophene derivatives, the geometry structures, frontier molecular orbital （FMO） energies, charge transport properties, and stability property were predicted by density functional theory methods. The calculated results reported herein show that the oligo[8]thiophene derivative with linear structure has smaller energy gap, and fused oligo[8]thiophene derivative with circular structure has the smallest reorganization energy among the designed molecules. We have also studied the stability properties of the designed molecules, and oligo[8]thiophene derivatives are more stable tharJ the fused oligo[8]thiophene derivatives.     

一种新的用于分类挖掘的动态示例学习算法

给出一种能够接受特征及变化的动态示例学习分类方法。该方法改进了传统的ID基于特征值的学习方法，其局限性在于不能理解和记忆特征的变化信息，尤其没考虑特征间的动态相关。改进后的方法能学习动态特征，接受的训练示例是特征值在一定间隔内的初值和终值，从中获取特征值及其在指定间隔的跃迁，该方法尤其能够挖掘出特征间动态相关关系。通过若干应用例子测试表明，该方法适用于具有多元动态相关特征问题的分类，在信息融合领域中有独到的用处。     

异型截面长杆弹侵彻半无限厚金属靶板实验研究

为了研究截面形状对长杆弹侵彻半无限金属靶板的最终侵彻深度的影响规律,开展了截面形状为圆形、三角形、正方形、十字形的等截面积的长杆弹侵彻半无限厚靶板的实验研究。实验分为两组,分别为长径比为8、弹芯材料为93钨合金的长杆弹侵彻装甲钢靶板实验以及长径比为15、弹芯材料为45钢的长杆弹垂直侵彻45钢靶板实验。实验后得到不同截面形状、不同长径比、不同弹靶材料的长杆弹在不同着靶速度下的侵彻深度。结果表明:三种异型截面长杆弹的侵彻能力均高于相同工况下的圆形截面长杆弹,且其中十字形截面长杆弹侵彻能力最优,正方形截面次之。通过对实验结果的宏观分析,得到三种异型截面长杆弹的截面形状对长杆弹侵彻半无限靶板侵彻威力的影响规律以及侵彻机理的宏观表现。     

铌酸银可见光催化降解聚氯乙烯薄膜

采用涂层法在玻璃基底上分别制备了纯聚氯乙烯(PVC)薄膜和添加水热法制备的钙钛矿型铌酸银(AgNbO₃)光催化剂的复合薄膜(PVC-wAgNbO₃, 其中w为AgNbO₃的质量分数), 在500 W氙灯照射120 min条件下进行了薄膜的光催化降解实验. 利用X射线衍射仪(XRD)、 扫描电子显微镜(SEM)和傅里叶变换红外光谱仪(FTIR)等对光照前后薄膜的形貌及光催化降解过程进行了表征. 结果表明, 在光催化降解过程中纯PVC薄膜失重率为4.09%, 而PVC-3%AgNbO₃, PVC-6%AgNbO₃, PVC-9%AgNbO₃和PVC-15%AgNbO₃复合薄膜分别失重20.36%, 23.52%, 27.62%和33.83%. AgNbO₃光催化剂加速了PVC薄膜的降解, 且随着AgNbO₃光催化剂添加量的增加, PVC薄膜的光催化降解速率不断增大.