有限元数值试井解释技术在复杂断块油气藏评价中的应用

有限元数值模拟试井技术,可通过描述不同网格的瞬变压力对测试范围内各个小单元进行精细描述.综合运用解析试井、数值试井联带分析方法,将测试动态成果与地质静态成果有机结合、相互补充,可实现对复杂断块油气藏的精细描述,达到一口井搞清一个小型复杂断块油气藏的目的.     

基于Web平台的机器翻译系统

用户可以通过Internet访问和使用机器翻译系统，在线机器翻译系统可以帮助用户阅读网上外文材料。用户一般通过购买相关软件或访问提供在线翻译的网站来获取翻译服务，但是专用软件价格昂贵，或者获得的在线翻译效果不能令人满意。通过Web服务与J2EE技术的结合，提出了将机器翻译拳统包装为Web服务的机制，使企业和个人能够以较低的代价方便地享受更高质量的翻译服务。     

NUMERICAL ANALYSIS OF THE EFFECTS OF LOCAL HYDRODYNAMICS ON MASS TRANSFER IN HETEROGENEOUS POROUS MEDIA

Many engineering problems require the estimation of mass transfer coefficients in porous materials. In heterogeneous materials or in cases where mass transfer sites are not spatially uniform, empirical equations for mass transfer coefficients vary widely, and the origin of these differences is not well understood. In this article, we use a stochastic algorithm to model mass transfer from single particles in a two-dimensional heterogeneous packed bed. The computed mass transfer coefficients are used to generate a distribution of local Peclet numbers in the bed. Detailed hydrodynamics are then used to interpret variations in the local Peclet number. The results show clear relationships between pore structure, streamline patterns, and mass transfer rates.     

生活中的慢性杀手--石化合成洗剂

文章回顾了石化合成洗剂的发展历史，从经历的五代产品的发展过程中可以看出它经历了一个环保到不环保再到环保的曲折过程分析了石化合成洗剂的主要成分及其清洗去污的作用原理着重指出目前使用的石化合成洗剂虽然给生活带来便利，但同时也给人体健康和生态环境都造成严重的危害；倡导使用新型环保型的第五代洗剂已成为新世纪中清洗剂发展的必然趋势。     

Engineering Computation and Analysis of Enhancing Efficiency for Folded Waveguide TWT in MMW

Large signal operating equations in TWT have been solved by numerical solve method. The relations between interaction efficiency and design parameters in TWT are analyzed. A fast engineering design method of enhancing efficiency for folded waveguide TWT by velocity resynchronization is described. The computation is shown that the efficiency of Ka-band folded waveguide TWT with double taper can be enhanced over twice as original tube. This method of approach is very useful for tube designer.     

Abstract Implementation of Algebraic Specifications in a Temporal Logic Language

A formal technique for incorporating two specification paradigms is presented,in which an algebraic specification is implemented by a set of abstract procedures specified in pre and post-condition style.The link between the two level specifications is provided via a translation from terms of algebraic specifications into temporal logic formulae representing abstract programs.In terms of translation,a criterion for an abstract implementation satisfying its specification is given,which allows one to check the consistency between the two levels of specifications.The abstract implementations can be refined into executable code by refining each abstract procedure in it.It is proved that the satisfication relation between a specification and its implementations is preserved by such refinement steps.     

钻机绞车滚筒体的窄间隙埋弧焊

针对钻机绞车滚筒体采用手工电弧焊工人劳动强度大、焊接效率低、质量不稳定及返修率高等问题,研制了钻机绞车滚筒体窄间隙埋弧焊专机。该专机由ESAB—A2埋弧焊电源和焊接小车、窄间隙焊头、滚轮架、防窜装置、旋转地线夹、三维焊接工作台、焊剂自动回收机组成。使用表明,采用该焊机焊接的滚筒体焊缝质量完全符合设计要求,合格率100%,焊接效率比原来提高6倍。每件滚筒体的焊接可降低人工成本约80%。     

阻燃沥青的研究进展与建议

介绍了对沥青进行阻燃处理的必要性、沥青的阻燃机理、常用阻燃剂的特性及其作用模式;参照塑料材料阻燃性能的测试手段介绍了常用的沥青材料阻燃性能的测试方法;最后分析了我国沥青阻燃的研究现状,指出了该领域存在的主要问题,并给出了相应的建议。     

Bias dependence of high-frequency noise in heterojunction bipolar transistors

Hawkins' isothermal model developed to study noise in bipolar junction transistors (BJTs) is modified to investigate bias-dependent noise in heterojunction bipolar transistors (HBTs) by incorporating thermal effects. It is shown that the inclusion of thermal effects into the high-frequency noise model of HBTs is necessary as the temperature of the device may become very different from the ambient temperature, especially at high bias current. Calculation of the noise figure by including the thermal effect shows that the isothermal calculation may underestimate the noise figure at high bias current. It is observed that noise at low bias is ideality factor n dependent whereas high bias noise is insensitive to the variation of n. Moreover, the common base current gain plays a major role in the calculation of the minimum noise figure. The excellent fit obtained between the theoretical calculation and the measured data are attributed to the inclusion of the bias-dependent junction heating as well as C/sub De/ and C/sub bc/ into the present calculation.