Si基膜片型气敏传感器微结构单元的热学性能

微结构气敏传感器由于其微型化、低功耗、易阵列化和易批量生产等优点而受到国内外研究者的广泛关注。利用微机电系统（MEMS）加工技术，制备Si基膜片型微结构单元，并分析其热学性能。这种单元工作区温度为-300℃时，加热功率约75mW；并且膜片工作区的热质量很小，温度可以于毫秒量级的时间内，在室温和450℃之间调制。利用这种微结构单元，可以在温度调制方式下，研究气敏薄膜的电学特性和敏感机理。     

锂离子电池Si_(1.81)Co_(0.6)Cr_(0.6)Zn_(0.2)/MGS复合负极材料的制备与性能

采用两步高能球磨法制备了一种新的锂离子电池硅基复合负极材料Si1.81Co0.6Cr0.6Zn0.2/MGS.用X射线衍射(XRD)和扫描电镜(SEM)表征了材料的组成和形貌结构.电化学测试表明,Si1.81Co0.6Cr0.6Zn0.2/MGS作锂离子电池负极材料有较好的电化学性能:首次可逆容量为561 mAh.g-1,50个循环后,可逆容量的保持率为91%.Si1.81Co0.6Cr0.6Zn0.2/MGS循环性能的改善归因于电极结构在循环过程中的稳定性.     

Topological Modeling of a One Stage Spur Gear Transmission

Finding a basis of unification for the modeling of mechatronic systems is the search subject of several works.This paper is a part of a general research designed to the application of topology as a new approach for the modeling of mechatronic systems.Particularly,the modeling of a one stage spur gear transmission using a topological approach is tackled.This approach is based on the concepts of topological collections and transformations and implemented using the MGS（modeling of general systems）language.The topological collections are used to specify the interconnection laws of the one stage spur gear transmission and the transformations are used to specify the local behavior laws of its different components.In order to validate this approach,simulation results are presented and compared with those obtained with MODELICA language using Dymola solver.Since good results are achieved,this approach might be used as a basis of unification for the modeling of mechatronic systems.     

基于本体语义的制造网格构建机理研究*

针对制造资源共享和协同制造的困难,提出了基于本体语义的制造网格系统的构建思路。首先定义了制造网格服务模型,以及制造网格环境中资源封装和运行管理的基本单元——制造服务域;然后提出了基于本体语义的制造网格的体系结构及其关键问题;最后详细分析了制造网格服务响应流程中基于本体语义的服务发现、制造服务域的构造以及制造网格服务的完成等活动的执行过程。     

基于MGS电子海图的雷达主动目标和被动辐射源显示技术的研究

基于MGS电子海图的雷达主动目标和被动辐射源显示技术可以有效改善主被动雷达的显示效果。本文介绍了该电子地图给用户提供的电子图元编辑的接口,具体阐述了主动目标和被动辐射源在电子地图上如何实时显示及更新,讨论了如何对电子海图的功能进行拓展和优化。     

Optimization of a Multi Gravity Separator to produce clean coal from Turkish lignite fine coal tailings

In this study, the beneficiation of two lignite tailings by Multi Gravity Separator (MGS) was investigated. The tailings samples from the Tunçbilek/Kütahya and Soma/Manisa regions have ash contents of 66.21% and 52.65%, respectively. Significant operational parameters of MGS such as solid ratio, drum speed, tilt angle, shaking amplitude, wash water rate, and feed rate were varied. Empirical equations for recovery and ash content were derived by a least squares method using Minitab 15. The equations, which are second-order response functions, were expressed as functions of the six operating parameters of MGS. The results showed that it is possible to produce a coal concentrate containing 22.83% ash with a recovery of 49.32% from Tunçbilek coal tailings, and a coal concentrate containing 22.89% ash with a recovery of 60.01% from Soma coal tailings.     

Application of artificial neural network to study the performance of multi-gravity separator (MGS) treating iron ore fines

The present article describes an attempt made to study the possibility of beneficiating low-grade iron ore fines of Barbil Area of Orissa state, India, using multi-gravity separator (MGS) after grinding the ?10 mm fines to < 75 micron size and prepare a pellet feed of 65% Fe content. For the performance analysis, an artificial neural network (ANN) mathematical modeling approach was attempted. A three-layer feedforward neural network with a backpropagation method has been adopted, considering the three significant parameters of MGS, mainly drum inclination, drum speed, and shake amplitude, were varied and the results were evaluated for grade, recovery, and separation efficiency. The results of beneficiation studies showed that good recovery of hematite is possible with simultaneous increase in Fe(T) grade from 50.74% to 65.26% with 71.25% recovery. The predicted value obtained by ANN shows good agreement with the experimental values.     

Modeling and optimization of fine coal beneficiation by hydrocyclone and multi-gravity separation to produce fine lignite clean coal

We evaluated the suitability, contribution to the national economy, and environmental impact of hydrocyclone and Multi-Gravity Separation (MGS) processes using fine-sized coal taken from the Soma coal sludge pond. The lignite coal tailings were treated by a two-stage concentration scheme for the recovery of fine clean coal. Pre-enrichment experiment parameters were determined by the Taguchi experimental design method, and the results were interpreted by the Statistical Packages for the Social Sciences (SPSS) 15.0 program to evaluate the optimum parameter values. The tailings initially contained 54.82% ash and had a LCV of 2,279 kcal/kg; after hydrocyclone pre-enrichment, the concentrate was 42.60% ash and had a calorific value of 2,573 kcal/kg (55.75% coal yield). After the final enrichment process, the ash of the pre-concentrated coal was decreased to 24.21% and left a clean coal with a base calorific value of 3,226 kcal/kg (36.16% coal yield). The total sulfur of the obtained clean coal was 0.52% and the combustible sulfur rate was 0.10%. To reduce the ash content of the obtained clean coal, a decantation process was performed that decreased the ash content to 21.84% and the base calorific value was increased to 4,109 kcal/kg.     

基于视觉显著计算的视频流媒体渐进式表达方法

为了有效解决视频流媒体传输网络带宽、播出视频质量和用户实时性访问之间的矛盾,本文提出了一种基于视觉显著计算的视频流媒体渐进式表达方法.在视频内容分析和理解的基础上,首先进行场景分类和视觉敏感区域提取;然后根据编码信息确定视频序列中各帧的重要性,估计帧内片层数据重要性;最后基于视觉显著计算的结果提出一种适应网络带宽和质量可伸缩的视频流媒体渐进式表达方法.采用中粒度质量可伸缩（MGS）编码,在模拟网络测试平台上分别针对集中式和分散式视觉敏感区域视频序列进行实验研究,实验结果验证了本文提出的基于视觉显著计算的视频流媒体渐进式表达方法的正确性和有效性.