基于UML的工作流引擎的设计与研究

由于工作流技术具有在异构环境中处理复杂事务的能力,所以在科学研究、电子政务和商务等方面引起了广泛的关注,工作流引擎是工作流管理系统的核心,本文以工作流管理联盟的工作流参考模型为基础,主要使用UML建模技术对工作流引擎进行分析与设计。     

基于模糊控制的智能交通系统

针对平面交叉口的智能交通信号控制,提出了多相位路口实时的模糊控制方案。根据各相位的车辆排队长度实际交通量,设计信号灯配时方案,减少车辆在路口的排队长度。对上述控制方案进行仿真实验,仿真实验结果表明,该控制方案能很好的改善实际交通状况,控制效果优于定时控制的方法,从而有效的提高平面交通路口的通行能力。     

基于声波与振动探测的地震灾害生命搜索系统信号分析

基于声波与振动探测原理的地震生命探测系统的研制在我国灾害生命搜索救助领域中占有重要位置.对于其中数理模型的研究是研制和开发声波、振动生命探测定位仪的基础.测试实验表明,在声波与振动灾害救助系统中,所采集的信号带有大量的随机噪声,为了提高信噪比,必然要进行滤波.本文用的是小波变换的去噪方法.同时,从传感器接收到的信号可能是从多个振源发出的,这就要涉及到多源信号的分离问题.为此,引入了独立变量分析（ICA）的分离方法和傅立叶变换加以解决.当找到需要的信号后,通过相关函数分析自动获取多道信号的相对时差,进而求取振源的位置.     

绝缘油溶解气体含量试验中存在的问题与讨论

若对GB/T17623—1998中的有关规定缺乏理解,在绝缘油的气相色谱试验中就难免会出现一些问题;本文结合机械振荡脱气法的试验原理,对其中较为典型的几个问题进行了有益的讨论,并提出一些建议。     

面向对象的稀土永磁同步电动机CAD系统

稀土永磁同步电动机结构复杂，设计计算量大。采用可视化的编程工具C＋＋Builder 6所开发的稀土永磁同步电动机CAD系统提出了一种直接设计法，可有效地完成电动机的电磁设计。介绍了该系统的结构、功能、特点及其软件实现方法，并通过一个设计实例，将CAD系统设计结果与实测数据进行比较，证明了CAD系统设计结果的准确性。     

Experimental study on start-up characteristics of loop heat pipes

Loop heat pipes (LHPs) are two-phase heat transfer devices which utilize theevaporation and condensation of the working fluid to transfer heat. It consists of anevaporator, a condenser, a compensation chamber (CC) and vapor and liquid lines. Fig. 1 shows the detailed structure of the evaporator, CC and condenser of a LHP.The basic principles of LHP were introduced in ref. [1]. When LHPs start to work, liquidis vaporized in the vapor grooves, the menisci formed in the wick develop c…     

Studies on the microstructure,optical and electrical properties of organic microcavity devices based on a porous silicon reflector

Due to its low-cost and mature technology, Si has consistently been the mostwidely used semiconductor in microelectronic industry. Nevertheless, as the photolitho-graphic line for integrated circuit devices becomes narrower and narrower, the quantumsize effect appearing in the devices will further limit the development of electronic in-dustry. Si-based optoelectronic integration can increase the operational velocity of inte-grated circuits because photon can propagate three orders faster than …     

Sensitive determination of DNA based on resonance light scattering enhancement of azocarmine G and CTAB

A new method for the determination of DNA was developed with azocarmine G（AG） in the presence of cetyltrimethylammonium bromide（CTAB） by the resonance light scattering （RLS） technique. The synthetic samples were determined with satisfactory results, and the reaction mechanism was also studied. The results show that under the optimum conditions, the weak RLS signal of AG can be enhanced by DNA, which results from the formation of a new ternary complex AG-CTAB-DNA with large size. Moreover, the enhanced RLS intensity at 552 nm is directly proportional to the concentration of DNA in the range of 0 - 1.0 μg/mL for fish sperm DNA （fsDNA） and 0 - 1.5μg/mL for calf thymus DNA （ctDNA）. Based on this, a new assay of DNA can be established. The detection limits （3σ） are 2. 1 ng/mL for fsDNA and 2.2 ng/mL for ctDNA, respectively.     

Effect of High-energy Ball Milling on Synthetic Reaction in Al-TiO2-C System

High-energy ball milling has a great influence on the temperature characters of synthetic reaction in Al-TiO2-C system by changing the size,distribution state and wet ability of reactants.Reaction temperature characters（reaction ignition time,ignition temperature time.the maximum temperature and temperature rising rate）were changed by different milling time.The longer the milling time.the earlier the reaction.the quicker the temperature rise and the higher the maximum temperature.When the milling time exceeded 10 hours,the reactivity of reactants was so high that the synthetic reaction could take place at 850℃ directly without a long time pretreatment at 670℃.The microstructure of synthetic composites became uniform and the reinforced particles（TiC and α-Al2O3）became fine with milling time increasing.     

工艺参数对冷坩埚连续铸造Ti6Al4V表面的影响

为消除冷坩埚连续成形钛合金铸棒表面缺陷，了解工艺参数对表面质量影响规律，并制备出无裂纹铸棒，通过正交试验和理论分析的方法，研究了不同工艺参数对表面质量的影响，研究表明：表面质量随功率和线圈匝数的增加而变坏，随抽拉速度和拉锭高度的增加先变好后变坏；各参数影响程度不同，线圈匝数影响最大，功率次之，抽拉速度再次，拉锭高度影响最小；铸造表面质量良好钛合金棒的工艺参数为：抽拉速度5mm／min，功率50kW，线圈3匝，拉锭高度30mm。