CBTC系统中现地工作站合设方案研究

在CBTC系统架构中,联锁上位机和列车自动监控(ATS)值班工作站作为两个独立的操作终端,承担着不同的功能和角色.随着CBTC系统产品在国内的广泛应用以及地铁精细化管理和减少维护设备要求的提出,运营方对联锁上位机和AT S车站值班工作站提出了合设的招标要求.为了实现此目标,文章通过对比分析CBTC系统架构中两个操作终端...     

Characterisation tools development for PEM electrolysers

Electrochemical impedance spectroscopy (EIS), current interrupt (CI) and current mapping (CM) were investigated as in-situ characterisation tools for PEM electrolysers. A 25 cm² cell with titanium anode and carbon cathode plates were utilised in this study. A commercial MEA consisting of 1 mg IrO₂/cm² on the anode and 0.3 mg Pt/cm² on the cathode was used. The electrocatalyst was deposited on Nafion^® membranes. The electrochemical losses in a PEM electrolyser namely: activation, ohmic and mass transfer losses were identified using EIS and CI and both the advantages and disadvantages of the methods were discussed. The current distribution over the membrane electrode assembly (MEA) at different current densities was measured using the current mapping method. It is also shown that under the given experimental conditions the current density decreases along the serpentine flow field.     

Effect of natural gas enrichment with hydrogen on combustion characteristics of a dual fuel diesel engine

Environmental benefits are one of the main motivations encouraging the use of natural gas as fuel for internal combustion engines. In addition to the better impact on pollution, natural gas is available in many areas. In this context, the present work investigates the effect of hydrogen addition to natural gas in dual fuel mode, on combustion characteristics improvement, in relation with engine performance. Various hydrogen fractions (10, 20 and 30 by v%) are examined. Results showed that natural gas enrichment with hydrogen leads in general to an improved gaseous fuel combustion, which corresponds to an enhanced heat release rate during gaseous fuel premixed phase, resulting in an increase in the in-cylinder peak pressure, especially at high engine load (4.1 bar at 70% load). The highest cumulative and rate of heat release correspond to 10% Hydrogen addition. The combustion duration of gaseous fuel combustion phase is reduced for all hydrogen blends. Moreover, this technique resulted in better combustion stability. For all hydrogen test blends, COV_IMEP does not exceed 10%. However, no major effect on combustion noise was noticed and the ignition delay was not affected significantly. Regarding performance, an important improvement in energy conversion was obtained with almost all hydrogen blends as a result of improved gaseous fuel combustion. A maximum thermal efficiency of 32.5%, almost similar to the one under diesel operation, and a minimum fuel consumption of 236 g/kWh, are achieved with 10% hydrogen enrichment at 70% engine load.     

悬吊氯化铵溶液液滴的结晶过程

研究了常温下悬吊氯化铵溶液液滴的结晶过程,讨论了初始液滴的大小、氯化铵浓度以及悬吊细丝对结晶过程的影响.在实验中观察到了沿液滴表面枝晶的生长过程,发现液滴成壳后的表面形态与成核时的液滴直径之间有一定的关系.为了深入了解声悬浮条件下溶液液滴的结晶过程,将两种不同条件下的结晶过程进行了比较,并由此对声悬浮液滴结晶过程做出一些推断.     

A continual improvement framework with integration of CMMI and six‐sigma model for auto industry

During the recent years, the major driving forces of customer preference, vehicle safety, environmental protection, and flat demand for new cars led to a proliferation of car models and associated price reduction in the auto supply chain. To react to the complex and competitive environment, auto suppliers are urgent to conduct continual improvement (CI) in an effective and systematic way. Thus, this paper presents a framework for CI. The Integrated Development System is proposed to integrate both capability maturity model integration and six‐sigma approach. By implementing the framework, an automaker can establish a solid process‐based management system, identify critical processes, and optimize these processes. For demonstrating the application of this framework, a case study is presented and the result shows that all expected processes' performance targets are achieved, which has dramatically improved by 70% compared with the past records. Apparently, the proposed framework would act as a useful reference to improve an organization's process maturity. Copyright © 2008 John Wiley & Sons, Ltd.     

分散染料可染聚丙烯纤维的研究

通过添加不同比例的高分子可染组分Ｅ１、Ｅ２，与聚丙烯共混纺丝制得了可纺性好的分散染料可染聚丙烯纤维。该纤维强度达３．５～４．５ｃＮ／ｄｔｅｘ，断裂伸长为３０％－６０％，满足服用纤维要求；其可染性较纯聚丙烯纤维有明显改善，在常压沸染条件下可染出多种中、浅色以至深色制品。对Ｅ１，Ｅ２总添加量为７％的可染聚丙烯纤维用ＢｌａｃｋＥ－ＥＸ，ＢｌｕｅＥ－ＥＸ等１０种染料常压沸染１ｈ，上染率在８０％以上，染色织     

公司CI战略的一体化管理与推进

公司ＣＩ战略管理的难点不在于制定战略本身，而在于如何有效地实施公司ＣＩ战略。为此，本文对公司ＣＩ战略的含义和特征进行了阐述；系统地分析了影响公司ＣＩ战略实施的五个方面，指出了它们在实施公司ＣＩ战略中的作用及其应注意的问题。在此基础上，重点讨论了公司ＣＩ战略实现一体化管理的含义及途径。     

基于MATLAB/RTW的车载无刷直流电机调速系统代码自动生成

介绍了一种根据系统仿真模型自动生成嵌入式C代码的嵌入式系统设计方法.结合基于英飞凌C164CI微控制器的车载无刷直流电机调速系统的开发,详细说明了使用MATLAB/RTW(实时代码工作空间)工具集将系统仿真模型自动转换为嵌入式系统C代码并编译下载到微控制器中运行的方法.还对仿真和实验数据进行了比较分析.结果表明,系统实际运行结果与仿真结果之间具有很高的相似性,从而验证了自动生成代码的正确性和可靠性.     

CI策划——现代企业形象制胜之法宝

当前世界已经进入靠企业形象赢得市场的时代,企业形象越来越被企业重视,CI策划作为树立企业形象的制胜法宝,是企业经营活动的最宝贵资源.文章结合CI的相关理论和实际案例,从企业理念、企业行为和企业视觉形象三方面出发,阐述了a策划在树立优良企业形象中的具体运用和现实意义.     

新型氮杂2-β-萘基苯并噁唑分子设计及其电子结构

为寻找可能的具有特殊性能的新型苯并(口恶)唑类分子材料,在取得对2-β-萘基苯并唑分子进行实验研究和理论分析结果一致的基础上,设计了一系列新型氮杂目标分子,用Hyperchem程序中的分子力学MM+方法对分子进行了优化,得到平面共轭几何构型. 用PPP-SCF-CI方法,对设计分子的电子结构进行了较为详细的探究. 结果表明,分子体系π电子总能量随氮杂原子引入数量呈线性下降. 在苯并唑环与萘环引入单氮杂原子后,FMO能级差显示相反效应. 多氮杂原子引入不同位置后,FMO能级差极值点两极分化,至5氮杂化达到极限. 结合其它电子结构信息,最终筛选出一些特性材料分子.