Radar Imaging Based on Iterative Algorithms

It has long been realized that the problem of radar imaging is a special case of image reconstruction in which the data are incomplete and noisy. In other fields, iterative reconstruction algorithms have been used successfully to improve the image quality. This paper studies the application of iterative algorithms in radar imaging. A discrete model is first derived, and the iterative algorithms are then adapted to radar imaging. Although such algorithms are usually time consuming, this paper shows that, if the algorithms are appropriately simplified, it is possible to realize them even in real time. The efficiency of iterative algorithms is shown through computer simulations.     

Abnormal dielectric characteristics of PMN-32%PT single crystal under dc bias

It has been reported that the single crystal of relaxor ferroelectrics (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-xPT) with the compositions near the morphotropic phase boundary (MPB, 0.28相似文献   

普可尼亚厚垣菌生物防治应用价值的室内初步评估

通过对8株普可尼亚厚垣菌（Pochonia chlamydosporium)的产厚垣孢子能力、在植物根际的定殖能力、分生孢子对土壤抑菌作用的敏感性及真菌对线虫Panagrellus redivivus的固定率等10项评价指标的测定，初步评估了这8株普可尼亚厚垣菌对线虫的生物防治潜力．结果表明366及284菌株各项指标均优于其它菌株，可以作为研制线虫生防制剂的出发菌株．此外，对普克尼亚厚垣菌的室内生防评估方法进行了分析．     

如何培养少年儿童对篮球训练的兴趣

篮球运动其本质就是一趣味性游戏，在篮球启蒙训练中首先要加强少儿篮球训练兴趣的培养，使他们在训练中具有持久性，保证清晰的感知，周密的思考，牢固的记忆，即使遇到一些困难和也会努力克服，自觉主动地投入训练中去，有意识的把学习兴趣转化为志愿，为今后从事篮球运动，直至培养终身篮球爱好奠定基础。     

"商业天使"为科技型中小企业带来福音

“一个具备创业经历的中年男性，他有可观的收入和管理得当的财产，通常在家或办公室不远的地方，每年投资一个高科技或制造类项目，期望在3—5年内卖掉它。”通俗定义下的商业天使投资概念曾经成就了美国的“硅谷“。早在1903年，5位天使投资者投资了后来成为经济巨人的福特汽车公司。而在1877年，贝尔电话公司在创建时也得益于天使投资。同样，人们耳熟能详的苹果公司和亚马逊网上书店也是在天使投资的帮助下走向全球。截至目前，据美国小企业局的保守估计，美国的天使投资者超过30万人，每个天使投资者平均投资额为80万美元。这些“具备创业经历的中年男性”爆炸式的增加，缓解了处在初创期的科技型企业的资金困境，使美国创业企业迅猛增长。     

Researching on quadrature conversion structures For an UWB demonstrative receiver

1. INTRODUCTION As the development of technologies of digital signal processing and integrated circuits, the structure of wireless communication system has been improved. Many schemes for software defined radio (SDR) systems have been developed since 1995, and they can be divided into five tiers of solutions according to their developing history and their definitions[1]. The five tiers are conventional hardware-implemented scheme; software-controlled radio scheme; SDR, that implements m…     

Self-assembling Characteristics of Amphiphilic Star Block Copolymers with a Polyelectrolyte Shell

1 Results Amphiphilic block copolymers are capable of forming supramolecular assemblies resembling those observed in nature,such as spherical micelles,worm micelles,and vesicles.Changing the solvent composition,ionic strength or pH of the polymer solution may induce the self-assembly of block copolymers or trigger the transition between the geometries of noncovalent assemblies.In the current work,we have synthesised starlike amphiphilic block copolymers having hydrophobic poly(methyl methacrylate),PMMA,core,and hydrophilic poly(acrylic acid),PAA,shell.The self-assembling characteristics of these polymers have been investigated in aqueous solutions by light scattering and direct visualisation by cryo-transmission electron microscopy (cryoTEM)[1]. Computer simulations along with the theoretical predictions made for the star-like system based on mean-field theory have been used to support the experimental observations[2]. The association of the starlike macromolecules resembles that of charged biopolymers,such as actin,since a balance between attractive and repulsive forces is required for the formation of cylindrical assemblies and can be manipulated by changing the pH or the ionic strength of the solvent[3].     

"三位一体"人才建设绩效评价模型分析

分析人才建设绩效并建立科学的绩效评价模型,对提高部队管理水平有十分重要意义.本文从基于收益、基于行为和基于满意度三个不同方位和层次对人才建设绩效的理论和数学模型进行了有益探讨.     

Experimental Observables on Nuclear Liquid Gas Phase Transition

Progress on nuclear liquid gas phase transition （LGPT） or critical behavior has been simply reviewed and some signals of LGPT in heavy ion collisions, especially in NIMROD data, are focused. These signals include the power-law charge distribution, the largest fluctuation of the fragment observables, the nuclear Zipf law, caloric curve and critical exponent analysis etc.     

加快知识产权事业发展增强区域自主创新能力

随着苏州工业园区建设快速推进,园区的知识产权工作有了长足的发展.今年1-5月份,园区专利申请累计209件,与去年同期相比增长48.2%;专利授权累计188件,同比增长126.5%.上半年园区注册商标502件（去年全年为571件）.在园区工委、管委会的正确领导下,园区加快知识产权管理体系、制度体系和服务体系的建设,全面推动知识产权战略实施,提高企业创造、运用管理和保护知识产权的能力,增强区域创新能力,实现园区产业结构优化升级,进而推动了园区科技、经济、社会的协调健康发展.