Fast convergent integral equation solution of strip gratings on dielectric substrate

A fast convergent integral equation solution to the scattering problem of a transverse electric/transverse magnetic (TE/TM) plane wave by a one-dimensional periodic array of thin metal strips on a dielectric substrate is described. The formulation of the integral equation is similar to that derived by Montgomery for a two-dimensional periodic array of thin conductors on a dielectric substrate. However, the basis functions which satisfy the appropriate edge conditions are incorporated here for the unknown current expansion on the strips. Following the standard Galerkin's procedure, one may readily determine the induced currents on the strips and thus the reflected and transmitted fields. Sample numerical results are given and good agreement with previously published data is obtained. It is found that the convergence rate of this method is improved by an order of magnitude. Also it is shown that the dielectric substrate has a strong effect on the scattering from the large spacing strip grating.     

靖边薄层云岩气藏对储层改造技术的地质需求

靖边气田古生界奥陶系马家沟组马五21和马五31气藏、已探明天然气地质储量530×108m3.气藏具有低压、低渗和低产的特征,非均质薄层云岩储集层产出能力受局部鼻状构造部位和岩性双重制约.天然裂缝发育程度差别大、且又分布不均匀.主要储层结构为缝洞-孔隙型和裂缝-孔隙型,因而压裂施工作业中,破压梯度高、延伸裂缝压力高、人工造缝缝宽窄.依据产能差别,将现有生产井分为Ⅲ种类型.文中提出采用王水酸化施工作业、层内爆裂--稠化酸酸化联作、层内爆裂--稠化酸携砂压裂联作的技术新方案,来提高气田采收率.     

浅析作业成本法在企业中的有效实施

本文通过对作业成本法及其应用情况的总结和归纳,就企业如何有效实施作业成本法进行了粗浅的探讨。     

Tunnel stability and arching effects during tunneling in soft clayey soil

A series of centrifuge model tests and numerical simulations of these tests were carried out to investigate the surface settlement troughs, excess pore water pressure generation, tunnel stability and arching effects that develop during tunneling in soft clayey soil. The two methods were found to provide consistent results of the surface settlement troughs, excess pore water generation, and the overload factors at collapse for both single and parallel tunneling. The arching ratio describes the evolution of the arching effects on the soil mass surrounding tunnels and can be derived from the numerical analysis. The boundaries of the arching zones for both single tunneling and parallel tunneling were determined. In addition, the boundaries of the positive and negative arching zones were also proposed.     

Iterative finite element model of nonlinear viscoplastic analyses for blended granular porous media

The iterative finite element model, in which an element is used to represent a single particle, is generated to analyze the global behavior of multiple-material aggregates of materially nonlinear viscoplastic particles. The generalized Maxwell model is used to define four types of specific nonlinear viscoplastic materials, which are the elasto visco-plastic matter with linear viscosity, the plasto visco-plastic material with linear viscosity, the elasto visco-plastic media with nonlinear viscosity, and the plasto visco-plastic media with nonlinear viscosity. The theory and relevant penalty iterative algorithm are developed to analyze the four representative mixed granular systems consisting of materially nonlinear viscous particles. To verify precision of stress calculation, solutions of an axis-symmetric radial flow problem are compared with results of the literature and they are in a great agreement. The results present here provide significant insight into the fundamental behavior of granular media under compaction conditions, including prediction of the overall aggregates stress-strain response.     

准噶尔盆地腹部超压层分布研究

准噶尔盆地腹部普遍发育深层（大于4000m）超压系统，很多钻井都钻遇超压。通过对超压段钻井、地质、测井、地震特征系统研究发现，超压段泥浆密度大幅增加，具有高声波时差、低电阻率以及地震低速的超压响应特征。利用Dix公式计算地震层速度和利用Fillippone公式计算地层压力，得到超压数据体。准噶尔盆地腹部超压在白垩系及其以下沉积地层中均有分布，超压层的深度范围不同。分1井西凹陷边缘以及昌吉凹陷西南有空层现象。超压顶面分布的层位由北往南、从东到西逐渐变浅，从三叠系顶部到白垩系底部。深部超压对油气分布和富集有着重要的控制作用，准噶尔盆地腹部超压层分布的研究将对本区油气勘探起积极的推动作用。     

一种制备磁性粉末的新技术--均匀颗粒成型法

采用均匀颗粒成型法（Uniform Dropler Spray-UDS）制备Fe基合金粉末，该方法制备的颗粒粒度分布均匀，性能一致，大大优于传统的粉末制备方法（如破碎法、气雾化），具有广阔的应用前景。本文分析了粉末制备过程中颗粒尺寸的影响因素，结果表明：颗粒的大小主要取决于坩埚底部小孔、坩埚内外气体压强差以及振荡频率三个独立变量。     

混凝土浇筑质量对钢管混凝土性能的影响

着重阐述钢管与其核心砼粘结强度对钢管砼承载影响问题 ,并介绍三种常用浇筑方式和检测方法。     

真空技术在污水处理中的若干典型应用

介绍了真空技术在污水处理中的几种典型应用，真空结晶法在以分离污水中具有结晶性能的固体溶剂；真空过滤脱水用于初沉池和消化池污泥脱水，真空浮选法通过制造负压条件加速浮选过程；还有真空搅拌、真空脱气等等。这些足以说明真空技术在污水处理乃至环境保护中占有重要的一席之地。     

工业建筑中钢结构的设计

钢结构已广泛应用于工业建筑中 ,本文叙述了工业建筑中钢结构的设计