New explicit formulas for the effective piezoelectric coefficients of binary 0-3 composites

The explicit formula for the effective dielectric constant of binary 0-3 composites (Poon and Shin, J. Mat. Sc. 39 (2004) 1277–1281) is extended into two explicit formulas for the prediction of the elastic properties of macroscopically isotropic 0-3 composites. By combining them with the explicit effective dielectric formula into a calculation scheme (Wong et al., J. Appl. Phys. 90 (2001) 4690), we obtained two new explicit formulas for the prediction of the d ₃₁ and d ₃₃ values for binary 0-3 piezoelectric composites. These two explicit formulas are applicable even when the inclusion volume fraction is high. Comparing with existing experimental data, they are found to fit more favorably than those predicted by Wong et al. and others. Also, being explicit makes these formulas much easier to be embedded into other effective property calculations for binary 0-3 composite materials.     

曲面搜索法推求暴雨强度公式参数

目的为解决暴雨强度公式参数在传统推求方法中所存在的非线性函数拟合的问题．方法应用黄金分割法将参数b和n的值固定，即将非线性函数进行线性化，并在由这两个参数所确定的曲面上，通过计算机的特性来搜索参数A1和C的最优值．结果通过对线性函数的拟合，可以依次得到4个参数的值，近而推得暴雨强度公式．结论经过对多个城市的暴雨强度公式推求与比较，曲面搜索法能够快速、精确地得出计算结果．有效地解决了传统推求方法存在的诸多弊端，计算误差远远小于国家规范要求．     

类似级配沥青混合料最佳油石比关系研究

利用压实热拌沥青混合料的空隙率和矿料间隙率等体积特性，考虑集料吸收沥青的情况，提出了“有效油石体积比”的概念，依据最佳有效油石体积比，分析研究了同类级配矿料的最佳油石比之间的关系，建立了具有普遍意义的关系式，并与新的公路沥青路面施工技术规范提供的预估公式作了比较.     

椭球参数对大地坐标转换的影响——大地坐标微分公式再推导

针对e(椭圆第一偏心率)与a(椭圆的长半轴)之间的函数关系,对大地坐标微分公式进行了再次推导,得出一种新的广义大地微分公式.对两公式进行比较,并用WGS-84坐标与BJ54坐标转换的差异进行计算、分析,结果表明:在小区域范围内,利用两公式进行坐标转换效果相差不大,但对测区范围较大的情况,新的大地坐标微分公式为获得GPS测点的高精度坐标转换,提供了有用的工具.     

钢筋混凝土梁受剪承载力计算公式的研究

基于《规范》(JTG D62-2004)第5.1.1条的规定、钢筋混凝土梁受剪承载力的试验成果和《统一标准》(GB/T50283-1999)的规定,对《规范》中钢筋混凝土梁的受剪承载力计算公式进行了分析.分析表明,该计算公式中使用立方体抗压强度标准值是欠妥当的,且该计算公式的可靠指标计算结果不符合《统一标准》的规定.同时以与现行《规范》中的计算公式相协调以及满足《统一标准》中目标可靠指标的要求为原则,提出了钢筋混凝土梁受剪承载力的计算公式,并进行了相关分析.分析表明,建议的计算公式满足《统一标准》的规定.     

A quadrature formula for integrals with nearby singularities

The purpose of this paper is to propose a new quadrature formula for integrals with nearby singularities. In the boundary element method, the integrands of nearby singular boundary integrals vary drastically with the distance between the field and the source point. Especially, field variables and their derivatives at a field point near a boundary cannot be computed accurately. In the present paper a quadrature formula for ??‐isolated singularities near the integration interval, based on Lagrange interpolatory polynomials, is obtained. The error estimation of the proposed formula is also given. Quadrature formulas for regular and singular integrals with conjugate poles are derived. Numerical examples are given and the proposed quadrature rules present the expected polynomial accuracy. Copyright © 2006 John Wiley & Sons, Ltd.     

钢丝铅淬火在炉加热时间的控制

对影响钢丝加热时间的因素进行了分析,根据作者总结出的对钢丝在炉加热时间计算的经验公式,对现有的热处理工艺进行调整,实践验证,能满足生产要求,提高了热处理钢丝产量.     

一类矩阵方程的简便解法

对一类矩阵方程的解法进行了讨论，在一定条件下给出了一种简便快速的求解公式，并举例给予说明。     

埕北32东营组油藏钻井液的配方优化设计

针对埕北 32东营组油层情况 ,评价了储层敏感性 ;研究了该区使用的海水低固相聚合物钻井液的性能及对该油层渗透率恢复值和滤液侵入深度等的影响 ,为该储层优选了防止油层污染的钻井液配方。     

On the Logical Foundations of Compound Predicate Formulae for Legal Knowledge Representation

In order to represent legal knowledge adequately, it is vital to create a formal device that can freely construct an individual concept directly from a predicate expression. For this purpose, a Compound Predicate Formula (CPF) is formulated for use in legal expert systems. In this paper, we willattempt to explain the nature of CPFs by rigorous logical foundation, i.e., establishing their syntax and semantics precisely through the use of appropriate examples. We note the advantages of our system over other such systems and discuss the significance of CPFs with regard to the formalization of legal reasonings using examples from the United Nations Convention for the International Sale of Goods.