内嵌式防屈曲支撑钢框架加固既有混凝土框架结构抗震性能分析

针对既有混凝土框架结构存在承载力、抗震性能不足等问题,本文在内嵌钢框架-防屈曲支撑加固既有框架的试验基础上,对两榀经该方法加固的框架-支撑结构、一榀纯框架结构进行有限元非线性分析,以便深入研究合理的加固参数。用ABAQUS建模,钢材采用硬化弹塑性模型,混凝土采用塑性损伤模型,采用单调水平加载位移增量控制方式进行有限元模拟分析,得出骨架曲线并与试验结果比对。在此基础上分析结构内部受力过程,内力重分配规律,研究钢框架-支撑及节点连接处工作状态,为以后采用类似加固方法进一步改进内部配置、优化结构设计提供科学依据。     

A hybrid genetic algorithm for the multi-depot open vehicle routing problem

This paper studies the multi-depot open vehicle routing problem (MDOVRP), a variant of the vehicle routing problem (VRP), in which vehicles start from several depots and are not required to return to the depot. Despite the vast amount of literature about VRPs, the MDOVRP has received very little attention from researchers. In this paper, a new hybrid genetic algorithm is presented for finding the routes that minimize the traveling cost of the vehicles. Computational results on a number of test instances indicate the proposed algorithm dominates the CPLEX solver and the existing approach in the literature. Meanwhile, experiments are conducted on multi-depot VRP benchmarks, and the results are compared with a sophisticated tabu search approach and an exact method.     

三星集团冰箱领域在华专利布局分析

作为最早进入中国冰箱市场的外资公司之一,三星集团长年致力于高端冰箱的研发和生产、并逐步形成自有品牌的核心技术发展特点,其在华冰箱领域的专利布局便很好的反应了该公司在中国冰箱市场的研发策略和市场定位。通过对三星集团在华冰箱领域的专利申请进行统计,围绕其在华冰箱领域专利申请的总体情况、专利法律状态和IPC类别分布情况展开具体分析,旨在给出该集团对于冰箱领域在华发展趋势和方向的参考。     

蓝色荧光粉Sr_(2-x)B_5O_9Cl:xEu~(2+)的合成及Tb~(3+)掺杂的影响

采用高温固相法在还原气氛下合成了Sr2-xB5O9Cl:xEu2+蓝色荧光粉,为四方晶系结构。Sr2-xB5O9Cl:xEu2+的激发光谱为一强而宽的谱带组成,发射光谱是位于439nm附近的宽带发射。研究了Sr2-xB5O9Cl:xEu2+荧光粉的最佳合成温度以及Eu2+及Tb3+的浓度对样品发光性能的影响。结果表明:温度为850℃、Eu2+和Tb3+的掺杂浓度分别为8%和4%时,Sr2-xB5O9Cl:xEu2+发光粉的发光强度最好。Sr2-xB5O9Cl:xEu2+中Eu2+发光中心的浓度猝灭主要是由于电四极-电四极相互作用引起的。     

VHF-PECVD制备微晶硅材料及电池初步研究

研究了用甚高频等离子体增强化学气相沉积(VHF-PECVD)方法制备的不同沉积气压下的微晶硅薄膜样品。随着沉积气压的逐渐增大,样品的沉积速率也逐渐增大;样品的光敏性和激活能测试结果表明：随气压的变化两者发生了规律性一致的变化;傅立叶变换红外(FTIR)测试表明制备的样品中含有一定量的氧,使得样品呈现弱n型;室温微区喇曼光谱测试分析得到样品的微晶化特征与IR的分析是一致的,用高斯函数对喇曼谱解谱分析定量得出了晶化程度;分析了H处理p／I界面对电池性能的影响;首次在国内用VHF-PECVD制备出效率达4．24％的微晶硅电池。     

Accurate solution for natural convection around single and tandem circular cylinders inside a square enclosure using SEM

In this article, the spectral element method is applied to produce and serve as accurate solutions of benchmark quality for the natural convection around single and tandem circular cylinders inside a square enclosure at Rayleigh number Ra?=?10⁴, 10⁵, 10⁶, and Prandtl number Pr?=?0.71. To capture the cylindrical boundary better, two cases of affine map with clear geometric meaning are introduced such that the collocation grids are well located on the physical boundary. An improved time-splitting method is applied to deal with the coupled pressure and velocity in the momentum equation, and the computational framework is further promoted in this work when solving the convection term such that no components in the coefficient matrices of the algebraic equations need to be updated as the computational time is advanced. Numerical solutions of high quality are presented by the average Nusselt number, maximum value and contours of stream function, isotherms, and the quantitative dimensionless temperature along the horizontal midline, which could be a reference result for this classical problem.     

面向协议一致性测试的测试序列生成方法研究

考虑到协议一致性测试中基于扩展有限状态自动机( EFSM)模型的测试序列生成仍然是一个尚无理想方法解决的开放性问题,提出了一种面向协议一致性测试的基于EFSM模型的测试序列生成方法.此方法将EFSM模型转换成确定化的EFSM (DEFSM)模型,并在转换过程中对EFSM模型中的条件和操作冲突进行检测并加以消除,此外,通过测试序列生成附加模块的协助,可将变量及其条件判定从DEFSM模型中分离出来,使得处理后的DEFSM模型等同于有限状态自动机(FSM)模型,从而将EFSM的描述优势和基于FSM模型的测试序列生成优势进行有效的结合.理论和实验分析结果显示了此方法的有效性.     

TD-LTE RAN承载技术方案分析

通过分析TD-LTE RAN承载需求,结合中国移动的TD网络建设现状,对中国移动的TD-LTE RAN承载技术方案进行描述和分析对比。     

我国大气环境PM2.5来源、分布、危害现状分析

从人体健康和环境影响两个方面分析了大气污染物PM10和PM2.5带来的危害。列举了我国部分大城市的PM2.5的检测数据、分析其污染源及环境的影响;通过对我国整体PM2.5的分析,指出各主要污染源所占的比重及存在的问题,为空气环境的治理提供参考。