电气设计中的几具计算与判断

在电气设计中，设计者遵照有关规定、规范，进行有针对性的设计，在设计中可能只有简单地依照规定进行一些必要的计算。但是任何规定都有一定的科学根据，因而可以通过一些计算寻找和总结出一些较简单的规律，这些规律在以后的设计工作中可以直接地判断和得出结论。而不必从头计算一次．这就是本文的出发点，现在就下列各个问题分别论述。     

yong分析有助于低温装置设计

通过反复比较或分析的方法，应用yong分析能进行低温过程和装置的最佳化设计。在广泛使用计算机进行设计计算的工业应用中，yong函数正象其他变量一样可以排入程序。因此，可以把计算yong消耗比怍循环过程或象精馏塔那样的装置。     

结构计算模型修正的区间反演方法

提出了结构计算模型修正的区间反演方法。该方法将计算模型修正问题归结为非线性全局优化问题，并采用一种遗传算法进行求解。方法考虑了作为修正参考值的试验模态参数具有一定误差，计算结果除可以给出修正后模型的估计值外还可以同时给出其不确定度，有利于对修正后计算模型的质量做出直观评价。算例表明本文提出的方法是可靠可行的，不仅可以判断采用的信息是否完备，而且可以对完备数据的稳定性情况进行判定。     

基于小波包分析的声强计算方法

传统的基于FFT的声强计算方法是分析平稳噪声信号的有效工具，但是它却无法对机电设备发生故障时所辐射出的非平稳噪声信号进行有效的分析。由于小波包分析可以实现非平稳噪声信号在不同频带和不同时刻的合理分离，因此可以利用小波包分析对声强进行计算。文中应用自行研制的噪声自动分析系统对声强的计算方法进行了研究，提出了一种基于小波包信号分析技术的声强计算方法：并通过实验验证了该方法的正确性。该方法不同于传统的基于FFT分析的声强计算方法，可以实现对非平稳故障噪声信号的分析，为机电设备的噪声监测和故障诊断提供了一条研究途径。     

矩形封闭长空间声场的高频计算方法

基于射线跟踪的思想，提出一种矩形封闭长空间声场预测的高频数值计算方法。该方法中只要具备声场空间的边界条件参数，即声场空间长、宽、高和吸声系数，就可以解析计算任何一根声线能量随时间的衰减变化，以及任何一根声线在任何时刻的到达坐标。如果逐一计算每根声线在特定位置的到达时间和声能量，并统计所有计算结果．就可以得到此处的时域脉冲响应，并由此计算声场声压级。该方法不必对声线进行跟踪，省去了建模、入射和反射等射线跟踪计算细节，运算量大为降低，因此计算速度很快。采用实验方法对该算法的性能进行了验证，对长空间中的声场进行测量，将测量结果与本文所提算法的计算结果进行对比，二者吻合很好，证实了该方法的有效性。     

计算特征向量及其导数的同步迭代法

以前的灵敏度分析方法都是先计算特征对然后再计算它们的导数，本文对特征对计算的矩阵迭代法及子空间迭代法进行改造，在迭代计算特征对的同时计算特征向量的导数。采用矩阵迭代法可以直接迭代计算特征向量导数，避免了对奇异灵敏度方程的求解。采用子空间迭代法可以将原来的大型特征方程和灵敏度方程缩阶为较小的方程。算例表明这两种算法精度较高，采用子空间迭代法计算多个特征向量对一个设计变量的导数计算效率较高。     

电厂继保整定计算系统关键技术分析

对发电厂继电保护整定计算系统进行了通用性和实用性研究，继而对其进行了总体设计和功能分析。通用的电厂继电保护整定计算系统通过可视化的方法，使用户可以直观地进行故障分析并结合自己的经验进行保护定值的整定。     

采用遗传算法进行车间平面布置

利用遗传算法进行车间的平面布置。计算结果表明，应用遗传算法求解车间布置问题不仅可以获得优化程度高的近似最优解，而且具有高的计算效率和很强的实际应用性。     

超声断面成象线阵的近场计算和分辨力估计

计算一定孔径的辐射声场，通常是根据惠更斯原理。应用菲涅耳近似或夫琅和弗近似可以简化计算。但是，大多数医用超声成象设备的检测区不能满足这些近似条件。本文以角谱法为主进行计算。这种方法物理意义明确，一般不必作任何近似就能进行数值计算，又便于采用ＦＦＴ算法，从而大大节约了计算工作量。文中结合计算实例对采样间隔、采样点数的选取进行了讨论。计算结果为研究线阵横向分辨力及拟定分段动态聚焦方案提供了依据。     

采用BP神经网络进行混沌运动控制

利用4层BP神经网络对非线性非连续函数的无穷逼近特性，设计了控制方法，对非线性系统的混沌运动进行控制。在系统发生混沌运动时，对于不同类型的期望信号，可以将不同自由度的混沌运动分别控制到各自的目标信号上。目标函数可以是周期函数，非线性函数。对Lorenz方程进行了仿真计算，结果显示可以将混沌运动控制到锯齿波信号、正弦信号和直流信号上；对Rossler方程的仿真计算，可以将系统的混沌运动控制到方波信号与直流信号上，控制所用的时间很短。     

Quality of life is not related with liver disease severity but with anemia, malnutrition, and depression in HCV-infected hemodialysis patients

Hepatitis C virus (HCV) infection may deteriorate quality of life. The relationship between HCV infection and quality of life in hemodialysis (HD) patients is unknown. The demographic characteristics, comorbidities, biochemical parameters, and Malnutrition-Inflammation Score (MIS) were recorded. Child-Pugh classification, Beck Depression Inventory, and SF-36 were performed. Liver histopathology was examined. Thirty-two patients (21 Child-Pugh-A, 11 Child-Pugh-B) were included. There was high-grade portal necroinflammatory activity in 14, high-grade lobular necroinflammatory activity in 26, and hepatic fibrosis in 19 patients. Three patients had cirrhosis. Patients with a high stage of liver fibrosis had lower social functioning scores than patient with a low stage of fibrosis (P= 0.011). The only correlation was between aspartate aminotransferase and the physical function subscale (r=−0.395, P= 0.025). None of the SF-36 scores differed between Child-Pugh A and B patients. Instead, most of the SF-36 subscale and summary scores were related with hemoglobin, albumin, MIS and Beck Depression Score. Quality of life in HCV-infected HD patients was independent of liver disease severity anchors, but was correlated with anemia, malnutrition, and depression.     

企业管理信息系统中的B/S和C/S结构的应用

文章以制造企业为例提出了企业管理信息系统的三维开发模型及企业信息化的实施方法，讨论了B／S和C／S的混合结构模式及JSP网络技术与网络数据库在企业管理信息系统开发中的应用。通过企业建模，掌握企业组织构架，了解企业如何工作，何处是瓶颈，为企业高效地运作提供了一种解决方案。     

管理信息系统结构划分的可拓算法

通过建立Ｕ／Ｃ矩阵的关联矩阵，对Ｕ／Ｃ矩阵的一致性检验、完备性检验和无冗余性检验等，用定量分析方法来实现。给出了Ｕ／Ｃ矩阵求解的可拓算法。最后，给出子系统划分的关联矩阵分析法，使ＭＩＳ的功能／数据分析过程可由计算机来实现     

基于Weibull模型的C/C复合材料销钉剪切强度分布及本构关系

针对C/C复合材料销钉力学性能各向异性的特点,开展基于Weibull分布模型的C/C销钉剪切强度分布及本构关系研究,探讨不同剪切方向对C/C销钉剪切强度和剪切本构的影响规律。基于两参数Weibull分布模型,采用最小二乘法获得不同剪切方向上剪切强度的分布规律;根据C/C复合材料损伤失效机制,采用基于Weibull分布的弹性损伤模型表征材料的剪切本构关系,并通过试验数据获取损伤模型中的参数。结果表明:通过Kolmogorov-Smirnov拟合优度检验,两参数Weibull分布模型能较好地表征C/C销钉剪切强度的分布规律;沿45°方向剪切的C/C销钉,其剪切强度最高;随着剪切角度的增大销钉剪切刚度逐渐降低,从0°方向上的19.46 kN/mm下降到90°方向上的12.70 kN/mm。      

单片机在绕线机定长测试仪中的应用

本文介绍了一种以89C51单片机为核心的绕丝机定长测试仪实现方案，阐述了其工作原理和软、硬件设计．系统中采用了具有电源监测和WDT功能的专用芯片，以解决工业现场中的抗干扰问题；同时，通过I2C总线扩展片外E2PROM来保存测试参数，以精简系统设计，保障异常后的现场恢复．该测试仪可应用在绕线机等其它需进行定长测控的场合．     

基于遗传算法和神经网络的C/C复合材料等温CVI工艺参数优化模型

建立了基于遗传算法和误差反传（GA-BP）神经网络的化学气相渗透（CVI）工艺参数优化模型。以新型等温CVI工艺制备C/C复合材料时采集的实验数据作为模型评价样本,分析了主要可控影响因素（沉积温度、前驱气体分压与滞留时间等）对C/C复合材料制件密度及其密度均匀性的作用规律。在该模型指导下,样本的期望密度和实测密度最大误差不超过6.2%,密度差最大误差不超过8.2%。实验结果也证明了该模型具有较高的精度和良好的泛化能力,可以用于CVI工艺参数的优化。      

Effect of high‐protein supplemental therapy on subjective global assessment of CKD‐5D patients

Adequate nutrition in patients on hemodialysis is an important step for improving the quality of life. This prospective study was undertaken to monitor the nutritional status of patients who were given high‐protein supplements on malnutrition inflammation score (MIS) and to correlate with biochemical parameters in maintenance hemodialysis (MHD) patients. This prospective study was conducted on 55 chronic kidney disease patients on MHD (37 women, 18 men), aged between 21 and 67 years. Of the 55 patients, 26 patients received high‐protein commercial nutritional supplements, whereas 29 patients received high‐protein kitchen feeding. Every patient had their MIS, 24‐hour dietary recall, hand grip, mid arm circumference, triceps skin‐fold thickness at 0, 3, and 6 months. Each of the above parameters was compared between the high‐protein commercial nutritional supplement cohort and high‐protein kitchen feeding cohort, and the data were analyzed. Of the 55 patients, 82.61% of patients on high‐protein kitchen feeding group and 66.67% in high‐protein commercial nutritional supplement group were nonvegetarian (P = 0.021). According to the MIS, improvement was observed in malnutrition status from 3‐ to 6‐month period in 38.1% of patients in high‐protein commercial supplement group, whereas only in 8.7% in high‐protein kitchen feeding group (P = 0.04). Assessment showed improvement in malnutrition status with high‐protein commercial nutritional supplement, which was marked in patients with age group >65 years (P = 0.03) and in those in whom serum albumin is <35 g/L (P = 0.02). Both high‐protein kitchen feeding and high‐protein commercial nutritional supplement cohorts were observed to have improvement in overall nutritional status. Older patients >65 years with lower serum albumin levels (<3.5 g/dL) were observed to have significant improvement in nutritional status with high‐protein commercial nutritional supplements.     

Entwicklung eines stoffschlüssigen Fügeverfahrens für Glaskohlenstoff und einem C/C–SiCN‐Verbundwerkstoff für ein innovatives Hochtemperatur‐Messsystem

Conventional high temperature (>1400 °C) measuring techniques are very limited. Thermal protective covering of temperature measuring elements in molten metals usually are single‐use systems. As a part of a research and development project a new temperature measuring system is being developed. The requirements for this protective cover are extremely complex. Not only does it has to be resistant to high temperatures, media in molten metals, fractures and thermal shocks, it also has to be gastight and thermal conductive. The compounds used currently for these covers don't fit this profile. Laminated C/(C/C–SiCN) hybrid composites are a new approach, consisting of glassy carbon and a C/C–SiCN composite. In order to ensure the media resistance of the protective cover a fitting lamination is applied by means of a thermal spraying. Due to the extreme requirements of the joining points the joining of this lens barrel hybrid composite with the gastight seal is quite difficult. The joints have to maintain an adequate mechanical stability and gasthightness for up to 700 °C. Other reliable joining techniques for graphite are supposed to be applied to glassy carbon. Regarding this active hard soldering was investigated. In this article conventional active hard soldering agents with varying titanium contents and under variation of other parameters are tested for their suitability as a soldering agent. The soldered samples were material graphically, micromechanically and fractographically characterised.     

遗传算法在C/C复合材料等温CVI工艺参数优化中的应用

阐述了采用基于遗传算法的数值优化技术对等温CVI工艺参数进行优化的方法和过程，并对2DC/C复合材料的ICVI工艺参数进行了优化。结果表明，该技术有助于降低实验成本，提高碳基、陶瓷基复合材料的制备效率和质量。     

Electrical properties of Ta2O5 films deposited on ZnO

High dielectric constant (high-k) Ta₂O₅films have been deposited on ZnO/p-Si substrate by microwave plasma at 150°C. Structure and composition of the ZnO/p-Si films have been investigated by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) for chemical composition. The electrical properties of the Ta₂O₅/ZnO/p-Si metal insulator semiconductor (MIS) structures were studied using high frequency capacitance-voltage (C-V), conductance-voltage (G-V) and current-voltage (I-V) characteristics. Charged trapping properties have been studied by measuring the gate voltage shift due to trapped charge generation under Fowler-Nordheim (F-N) constant current stressing.