改进低密度鞋底原液工艺性能的添加剂

研究了硅氧烷-聚醚共聚物匀泡剂的结构组成对低密度微孔聚氨酯鞋底料性能的影响，介绍了新型匀泡剂DC3042及DC3043在低密度鞋底料中作用，其中DC3042可改善泡孔结构及制品表现质量，而DC3043具有改善尺寸稳定性的作用，两种复配可得到满意的效果。还介绍了催化剂Dabdo1027及Dabco1028与现有催化剂复配使用可缩短脱模时间或延长乳白时间。     

复结构奇异值的几何解释及其计算:两块情形

应用几何方法给出两块情形复结构奇异值的几何解释,并提出一种简单迭代计算方法.该 方法求的是结构奇异值的真值而非其某一上界或下界.     

Service Locating for Large-Scale Mobile Ad-Hoc Network

In a mobile ad-hoc network, an efficient service discovery system is needed to locate various service providers. However, because an ad-hoc network has no fixed topology, its service locating is quite different from traditional schemes for the Internet. In this article, we present a novel service locating system specifically designed for large-scale mobile ad-hoc networks. In our system, a subset of nodes is dynamically elected and self-organized into a virtual backbone (VB). These VB nodes manage the directory information of services and monitor path quality of service on behalf of end users. Such information is then used to direct the selection of appropriate providers. We evaluate the performance of our system through simulation. The result demonstrates that the proposed locating system greatly improves the quality of service delivery while maintaining reasonably low cost.     

500 m口径球面射电望远镜索网结构形态和受力分析

500m口径球面射电望远镜(Five-hundred-meter Aperture Spherical radio Telescope,FAST)是国家重大科技基础设施项目。口径500m、半径300.4m的球冠形索网是FAST反射面的主体支承结构。通过促动器的主动控制,索网可以在标准球面和不同抛物面之间转换,即索网为可主动变位的结构。针对FAST索网结构设计中由主动变位引起的形态分析和轻量化需求等问题开展研究,提出了目标位形应变补偿法,统一了球面基准态和抛物面态的形态分析方法,解决了多目标位形索网结构的形态分析问题;提出预应力优化方法,将球面基准态最大索力降低了29%;研究了索网球面基准态和抛物面态的受力性能,并与实测结果进行对比,索力吻合较好,50%以上钢索索力相对误差在5%以内。     

望京搜侯中心T3塔楼动力弹塑性分析

借助三维非线性结构分析软件Perform-3D对望京搜侯中心T3塔楼进行大震下的动力弹塑性分析,考察了结构在实际地震作用下的动力响应及关键部位、关键构件的塑性发展情况,评价了结构的抗震性能,并对工程设计提出了改进建议。     

加强液化石油气贮运、供应等环节的安全管理

针对液化石油气这种危险化学品所具有的易燃、易爆特性,从贯彻落实《危险化学品安全管理条例》入手,围绕组织机构设立、建立规章制度、证照管理、教育培训、登记注册等方面,讨论加强危险化学品的安全管理工作。     

Intermittency in Switching Power Converters: Theoretical Analysis

In view of reasonable explanation of intermittent subharmonics and chaos that can be gained from coupling filter between circuits, this paper discusses a method that maps time bifurcation with parameter bifurcation. Based on this mapping method, the general analysis method of characteristic multiplier, which is originally aimed at parameter bifurcation, can be used for the study of intermittency, i.e., time bifurcation. In this paper, all researches coming from characteristic multipliers, parameter-bifurcation diagrams, and the largest Lyapunov exponent indicate the same results as those produced by simulation and experiment. Thus, it is proved theoretically that the intermittency in switching power converter can be explained in terms of coupling of spurious interference. Translated from Acta Electronica Sinica, 2004, 32(2): 269–273 (in Chinese)     

基于LabVIEW的布里渊信号的检测与识别

本文介绍了虚拟仪器的开发环境LabVIEW的特点,分析并利用动态链接技术实现LabVIEW和C语言的接口技术对布里渊散射信号的检测与识别。从而实现基本的自动探测,改变仍需要人用眼睛判断是双环还是单环结构以得出是否有物体的结论。     

Corrosion behavior of Cu during graphene growth by CVD

The corrosion performance of Cu samples may be affected by annealing at high temperatures during graphene growth via the chemical vapor deposition method. In this study, multiple graphene films were deposited on Cu and characterized by Raman spectroscopy and transmission electron microscopy. The corrosion behavior of Cu immersed in 3.5 wt.% NaCl solution was investigated using electrochemical impedance spectroscopy. The Cu morphology was observed by optical microscopy and scanning electron microscopy. Results indicated that annealing affects the corrosion process of Cu. The presence of graphene films on the Cu substrate improved the corrosion performance of the material for a short period of time.