脉冲相干激光雷达对运动目标成像模拟

针对运动目标，在考虑激光雷达方程、信噪比和自动增益、成像指标、噪声、图像处理等模块的基础上，对脉冲相干成像激光雷达进行了运动目标的成像模拟。     

BEPCⅡ高频发射机和环流器的调整和测试

北京正负电子对撞机升级改造工程(BEPCⅡ)将采用的频率500MHz、输出功率250kW的高频发射机和环流器已安装、调整、测试和验收完毕,这是国内建立的第一套500MHz/250kW发射机系统.本文将详细介绍机器的调测试的原理和各项测量内容及结果, 并比较设计指标和要求,来阐述此发射机的实际技术指标和测试性能.     

Demonstration of Soliton Solutions of DNLS Equation by Liouville Theorem

In the inverse scattering transform (IST), the reflectionless Jost solutions are combined by their analytic properties in the complex spectrum parameter plane, and then can be shown to satisfy the two Lax equations indeed by Liouville theorem. So the corresponding soliton solutions certainly satisfy the nonlinear equation by compatibility condition. Especially the multi-soliton solutions of DNLS equation can be demonstrated in this way. PACS Numbers: 05.45.Yv, 02.30.-f, 11.10.Ef     

Approximation of Matrices and a Family of Gander Methods for Polar Decomposition

Two matrix approximation problems are considered: approximation of a rectangular complex matrix by subunitary matrices with respect to unitarily invariant norms and a minimal rank approximation with respect to the spectral norm. A characterization of a subunitary approximant of a square matrix with respect to the Schatten norms, given by Maher, is extended to the case of rectangular matrices and arbitrary unitarily invariant norms. Iterative methods, based on the family of Gander methods and on Higham’s scaled method for polar decomposition of a matrix, are proposed for computing subunitary and minimal rank approximants. Properties of Gander methods are investigated in details. AMS subject classification (2000) 65F30, 15A18     

建立军用Foundry的探索

本文从ASIC的基本特点出发,阐述了建立ASIC标准加工线(Foundry)的重要性;国内集成电路产业已经具备建立Foundry的基础,建立有中国特色的Foundry是可以有所作为的。文章介绍了作者在建立军用Foundry方面的探索和初步成果。     

基于CMDCT的AAC编码器心理声学模型的改进

本文提出一种改进的MPEG4-2／4AAC编码结构。与ISO标准参考结构中平行进行DFT和DMDCT不同，改进结构里感知模型和编码器中的时域到频域变换的计算都基于CMDCT进行，将两次变换合并为一次。在保持编码质量的同时，降低了变换部分的计算复杂度。新结构中变换的计算形式得到统一，更加适合编码器的VLSI实现。     

X射线聚束透镜原理及其应用

本文阐述了一种新型的Ｘ射线聚束装置─—Ｘ射线透镜的聚束原理。给出了透镜的基本设计方法，并对它应用于Ｘ射线光刻研究领域的前景作了展望。     

Bioaccumulation and excretion of arsenic compounds by a marine unicellular alga,polyphysa peniculus

Polyphysa peniculus was grown in artificial seawater in the presence of arsenate, arsenite, monomethylarsonate and dimethylarsinic acid. The separation and identification of some of the arsenic species produced in the cells as well as in the growth medium were achieved by using hydride generation–gas chromatography–atomic absorption spectrometry methodology. Arsenite and dimethylarsinate were detected following incubation with arsenate. When the alga was treated with arsenite, dimethylarsinate was the major metabolite in the cells and in the growth medium; trace amounts of monomethylarsonate were also detected in the cells. With monomethylarsonate as a substrate, the metabolite is dimethylarsinate. Polyphysa peniculus did not metabolize dimethylarsinic acid when it was used as a substrate. Significant amounts of more complex arsenic species, such as arsenosungars, were not observed in the cells or medium on the evidence of flow injection–microwave digestion–hydride generation–atomic absorption spectrometry methodology. Transfer of the exposed cells to fresh medium caused release of most cell–associated arsenicals to the surrounding environment.     

2～12GHz GaAs单片行波放大器

报道了一个全平面超宽带ＧａＡｓ单片行波放大器的研究结果。该单片电路的核心部件是四个３００μｍ栅宽的ＭＥＳＦＥＴ，整个电路拓扑结构简单，芯片面积为３．０ｍｍ×１．８ｍｍ。电路经优化设计后在２～１２ＧＨｚ范围内，小信号增益为５±１ｄＢ，输入输出电压驻波比≤１．７５。上述频率范围内输出功率≥１６ｄＢｍ，噪声系数≤８ｄＢ。采用全离子注入、全平面工艺，均匀性、一致性良好。实验结果与设计预计值十分一致。     

CVD金刚石工具膜生长特征SEM观察

本文用不热形变栅状直丝化学气相沉积（ＣＶＤ）法生长金刚石膜，在Ｓｉ及ＷＣ－Ｃｏ硬质合金衬底上金刚石膜晶面显露规律随衬底温度和甲烷浓度而异，经适当表面处理及选择合适的工艺条件，当生长初期衬底上就呈现出良好晶形的沉积膜，衬底与膜之间的粘结力能得到提高。Ｒａｍａｎ谱分析表明此膜仅具有特征金刚石１３３２ｃｍ￣（－１）峰，通过ＳＥＭ观察揭示出盒刚石膜可在表面、侧面及棱上生长，并与衬底有良好的联结。