变频调速节能改造方案的经济性评价和比较

本文详细介绍了变频调速节能改造方案的经济性评价方法。静态分析法包括投资回收期法、抵偿年限法和年计算费用法；动态分析法则包括净现值法、内部回收率法、总费用现值法和最小年费用法。     

Numerical Simulation of Deforming Manufacture Process for Automobile Bevel Gear Blank

1 Introduction Rear axle bevel gearis a vital kind of annular accessory with high precision and hugeload availablefeatures ,andit is widely used as the differential drive in automobiles and tractor .In China ,the traditional manufactureapproach of producing the rear axle bevel gear blankis die forging,which not only requires a highinvestment ofproduct equipments , but also involves a low material utilization and great noise .In order to overcome thesedrawbacks , manyresearchers have done a gre…     

Continued fraction for formal laurent series and the lattice structure of sequences

Besides equidistribution properties and statistical independence the lattice profile, a generalized version of Marsaglia's lattice test, provides another quality measure for pseudorandom sequences over a (finite) field. It turned out that the lattice profile is closely related with the linear complexity profile. In this article we give a survey of several features of the linear complexity profile and the lattice profile, and we utilize relationships to completely describe the lattice profile of a sequence over a finite field in terms of the continued fraction expansion of its generating function. Finally we describe and construct sequences with a certain lattice profile, and introduce a further complexity measure.     

济阳坳陷地层圈闭成藏特征及地质风险评价

济阳坳陷地层圈闭分为地层超覆不整合、地层削蚀不整合遮挡两种类型，多发育在凹陷与凸起结合的斜坡部位．环绕凹陷呈裙带状分布，其成藏受不整合面控制作用明显。由于距离烃源岩较远，油气运移聚集条件成为地层圈闭成藏的主要控制因素。针对各项评价要素，可分别采用钻探成功率分级法、累计概率曲线法、地质分析法建立其地质风险评价标准。为了反映不同评价条件及评价要素在成藏及圈闭描述识别中的作用，可利用“评价要素加权求和”的方法计算5项评价条件的评价值，在此基础上，利用“5项条件评价值加权求和”的方法求取圈闭地质风险系数。应用表明，所建立的地质风险评价标准，能反映济阳坳陷地层圈闭勘探的实际情况。     

无创血压测量方法的研究

简要介绍了血压测量技术的发展概况，重点介绍了示渡法工作原理、判别准则和方法比较，对测量算法进行了详细介绍，并结合MOTORLA公司的MC68HC908LJ12简要介绍了示波法电子血压计实现方法，最后就影响血压测量的主要因素进行了简要分析。     

升平气田产能预测方法

依据升平气田的试井资料，建立了气井产能与压差之间的二次项产能方程。运用此方程可以预测升平气田的单井产能，并且建立了压差平方与kh值相关的气田综合产能方程。当求得气田的平均kh值后，利用该方法可以求得气田的平均产能或生产压差。     

水平井现场地质导向方法及其应用

为了降低水平井的钻探工程成本，要尽量不钻或少钻导眼井段。根据水平井在钻前准备、深度预测、稳定井斜、水平导入4个阶段的不同作业特点，依据现场施工经验，归纳提出了利用公式法、小导眼法、曲线指示法、扭矩与dc指数法等方法进行地质导向的成功实践。利用这些方法，可以有效地指导现场钻井人员，将钻井轨迹比较准确地导入目的层中。     

压缩机环状阀工作过程冲击应力的有限元分析研究

针对压缩机环状阀结构和运动特点,利用ANSYS分析软件对其冲击应力进行有限元分析,得出阀片质量和阀片倾侧运动对环状阀工作过程冲击应力的影响。为压缩机环状阀的结构修改和优化设计提供了必要的基础。     

Deflections of highly inflated fabric tubes

Inflatable beams made of modern textile materials with important mechanical characteristics can be inflated at high pressure. The aim of the paper is to present experimental, analytical and numerical results on the deflections of highly inflated fabric tubes submitted to bending loads. Experiments are displayed and we show that tube behaviour looks like that of inflatable panels (Thin-Walled Struct. 40 (2002) 523–536). Equilibrium equations are once again written in the deformed state to take into account the geometrical stiffness and the following forces. The influence of the shear stress cannot be neglected and Timoshenko’s beam theory is used. A new inflatable tube theory is established and simple analytical formulas are given for a cantilever-inflated tube. Comparisons between analytical and experimental results are shown. A new inflatable finite tube element is constructed by use of algebraic operations, because the compliance matrix of the cantilever beam is not symmetric. Comparisons between experimental, analytical and numerical results prove the accuracy of this beam theory and on this new finite element for solving problems on the deflections of highly inflated tubes.