PRO／E钣金展开分析法

通过Pro/E与传统的饭金展开原理的比较分析,阐明了Pro/E原理展开方法的优越性和实用性,为钣金的展开加工提供了一个高效的展开工具.     

A tree-structured crash surrogate measure for freeways

In this paper, we propose a novel methodology to define and estimate a surrogate measure. By imposing a hypothetical disturbance to the leading vehicle, the following vehicle’s action is represented as a probabilistic causal model. After that, a tree is built to describe the eight possible conflict types under the model. The surrogate measure, named Aggregated Crash Index (ACI), is thus proposed to measure the crash risk. This index reflects the accommodability of freeway traffic state to a traffic disturbance. We further apply this measure to evaluate the crash risks in a freeway section of Pacific Motorway, Australia. The results show that the proposed indicator outperforms the three traditional crash surrogate measures (i.e., Time to Collision, Proportion of Stopping Distance, and Crash Potential Index) in representing rear-end crash risks. The applications of this measure are also discussed.     

直拉单晶炉减薄型加热器的数值模拟与实验分析

在直拉单晶炉中使用一种减薄型加热器替代原加热器,改变了单晶炉的热场温度分布。通过有限元模拟分析软件对减薄型加热器进行模拟分析,模拟结果指出减薄型加热器对提升单晶拉速、降低单晶炉功耗具有促进作用。通过对比两种加热器装料量,并进行单晶生长对比实验,实验指出,减薄型加热器在引晶、等径、收尾阶段均降低了功耗,提升了拉速。最后,数据分析指出减薄型加热器的经济性比原加热器有一定提升。     

激光修补技术在修复薄膜图形缺陷上的应用——薄膜图形缺陷激光修补机

阐述了应用激光修补技术在玻璃基板上去除金属及其化合物薄膜和在玻璃基板上沉积金属薄膜的图形缺陷修补原理与方法;简述了影响薄膜图形缺陷修补质量与效率的关键技术;简单介绍了薄膜图形缺陷激光修补机的系统构成及其技术与性能指标.     

一种基于波导E-T结的新型功分器的设计方法

针对传统功分器的不足,提出了一种改进型波导E-T结功分器。通过三维电磁仿真软件CST对其进行了建模仿真,得到一个合理的设计方案,该结构具有高隔离度、低插入损耗、小体积、宽频带等优点。加工的实物经测试在12~17 GHz的频率范围内,该功分器的插入损耗＜0.12 dB,回波损耗＞18 dB,隔离度＞15 dB,具有良好的工程应用价值。     

How Modifying Third‐Party Information Affects Interpersonal Impressions and the Evaluation of Collaborative Online Media

Previous research has drawn upon warranting theory to help explain how viewers evaluate people and entities online. Extending previous research, this study assesses how the ability of a target to modify third‐party information affects perceptions of warranting value, and in turn, interpersonal impressions and the perceived legitimacy of online media that host evaluations. Additionally, this work explores how the perceived objectivity of a third‐party evaluator affects impressions in online settings. The results provide support for warranting theory and help clarify how impressions are formed in online environments when people have the ability to generate and modify content collectively. The theoretical implications this study has for warranting theory and future research directions are discussed.     

基于Pro／ENGINEER的接链环结构设计分析

以往多采用经验类比设计与传统材料力学简化计算相结合的方法对模型进行分析，这种方法在很大程度上取决于设计人员的经验，并且往往便设计偏于保守，致使产品质量大、成本高。随着各种先进计算机辅助设计软件的推广应用，采用功能强大的CAD和CAE软件对接链环结构进行分析成为可能，从而大幅度提高设计质量和效率。链传动广泛地应用在采矿运输没备中，接链环是整个没备正常工作的核心。在采煤过程中，接链环一旦被拉断，整个没备就处于瘫痪状态，后果非常严重，基于此种情况，目前还没有先进的检测仪器．Pro／E是CAD／CAE集成化软件，本文用它对链接环进行歧计分析，确定出应力集中的部位，也就是容易断裂的部位，然后进行了优化：     

一步法合成(E)-1,3-二取代丙-2-烯-1-酮类化合物

报道了一种温和的,以二氧化锰为氧化剂,通过串联氧化反应-Wittig反应-氧化反应,一步制备(E)-1,3-二取代丙-2-烯-1-酮类化合物的合成方法。使用该方法,我们合成7个具有代表性的化合物。     

微胶囊化电子墨水的研究现状及其应用

微胶囊化电子墨水具有便携性高、双稳态、低损耗、宽视角、高对比度反射型显示等优点,可以用来制备电子纸.在介绍电子墨水原理的基础上,着重阐述了微胶囊制备方法及研究进展,并评述了电子墨水材料的应用现状和发展趋势.     

HSDPA技术的引入对WCDMA R99系统Iub传输影响分析

本文介绍了HSDPA Iub接口的协议框架,并且通过对HSDPA技术特性的分析和系统仿真,得到了当HSDPA与WCDMA R99共载频设置时的传输需求,给出了基站传输设计的带宽参考值.