计算两参数对称音叉式分岐曲线扩张系统的构造

构造了计算两参数分岐线的扩张系统，讨论了扩张系统的正则性。     

万家寨水电站经济运行的措施

针对黄河近几年来水量逐年减少和电力市场的变化 ,对提高万家寨电站的经济运行效益问题 ,进行了分析     

加速基因方法在最大流量频率曲线参数估计中的应用

基因方法是基于自然选择和自然基因机制的并行随机自适应工程模型参数全局优化估计的通用数值方法。它不限制模型结构、优化准则、被估参数的数目、约束条件等，已开始广泛用于各种工程模型的优化设计之中。文中对它的原理、步骤、特点进行初步探讨，并针对基因方法的弱点，作者提出予以改进的加速基因方法，后者在最大流量频率曲线参数估计中得到成功应用     

平面四点确定一条抛物线及其在参数插值中的应用

本文讨论了用平面有序四点确定一条抛物线及其在参数插值中的应用。提出了有用四点确定一条抛物线的算法，讨论了确定抛物线的四点相互间要满足的位置。对平面给定的一组数据点，提出了构造参数插值曲线的新方法。所构造的插值曲线是ＧＣ＾１连续的分片三次参数曲线，其插值精度为二次参数多项式。本文还以计算实例对新方法与其它方法的插值精度进行了比较。     

空间曲线拟合算法的研究

在数控加工中，通常需要将空间曲线用合适的样条拟合出来，以方便加工．B样条概念于20世纪40年代由Sehoenberg提出后，已广泛应用于曲线、曲面的造型中．该文以变直径、变螺距的转向蜗杆的空间曲线为例，介绍了用B样条拟合空间曲线的方法，具体讨论了空间曲线反求控制点的计算方法，通过模拟仿真，该方法所拟合的曲线比较平整光滑、误差较小．用此方法拟合出的曲线可以直接用API得出加工程序．     

渐开线齿轮点蚀位置的确定及其计算综合曲率半径的误差修正

依据赫兹强度理论 ,指出一对标准渐开线直齿齿轮啮合时 ,最大接触应力位于齿轮单啮合区靠近小齿轮处单双啮合区的分界线上。小齿轮点蚀发生在分度圆与齿根圆之间 ,大齿轮点蚀发生在分度圆与齿顶圆之间。并列举实例 ,证明目前传统设计方法计算点蚀处齿轮综合曲率半径误差较大 ,绘制出精确计算值与传统计算值的比值曲线 ,并给出结论 :传统设计方法得到的结果不安全 ,有误差 ;误差与齿轮模数无关 ,误差随着小齿轮齿数的增加渐小 ,误差随着齿轮齿数比的增大先渐大后渐小     

Characterization of PdAg/Al2O3 composite membrane by electroless co-deposition

In this work, PdAg/Al₂O₃ composite membranes prepared by electroless co-deposition technique have been studied. Effects of plating time, Ag composition and total concentration of metal ions on surface morphologies, composition and microstructure of the resulting layers were investigated. Scanning electron microscope, energy dispersive spectrometer and nitrogen permeation technique were used to characterize the as-prepared composite membranes. From the experimental results, it shows that the surface morphology of the deposited PdAg layer is strongly affected by the Ag content of the plating bath. Since large differences of deposition rates and growth modes are observed between Pd and Ag grains, the PdAg layer exhibits the dendritic structure. As the Ag content is approximately 50%, the dendritic structured PdAg layer reveals the largest nitrogen permeability with the smallest size of residual pores. Furthermore, a comprehensive electrochemical analysis is proposed to interpret the composition and structure of the PdAg layer. Eventually, the experimental results are quite consistent with those predicted from the electrochemical analysis.     

Generalized Deformation Curve for High-Strength Steel over a Wide Range of Strain Rates

Test results for different high-strength steel specimens in static and impact tension and compression over a wide range of strain rates were summarized. These data were used to calculate the generalized deformation curve. The calculations based on this curve were compared with the experimental data on impact indentation with the conical indenter to evaluate the applicability of this method for studying the behavior of metals at high strain rates.     

Structured Latent Curve Models for the Study of Change in Multivariate Repeated Measures.

This article considers a structured latent curve model for multiple repeated measures. In a structured latent curve model, a smooth nonlinear function characterizes the mean response. A first-order Taylor polynomial taken with regard to the mean function defines elements of a restricted factor matrix that may include parameters that enter nonlinearly. Similar to factor scores, random coefficients are combined with the factor matrix to produce individual latent curves that need not follow the same form as the mean curve. Here the associations between change characteristics in multiple repeated measures are studied. A factor analysis model for covariates is included as a means of relating latent covariates to the factors characterizing change in different repeated measures. An example is provided. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

UG应用技法

通过使用UG规律曲线和自由曲面建立的命令，一步一步掌握UG高级建模方法。