Shear ductility and toughenability study of highly cross-linked epoxy/polyethersulphone

The objective of the present study was to determine whether the ductility and toughenability of a highly cross-linked epoxy resin, which has a high glass transition temperature, T _g, can be enhanced by the incorporation of a ductile thermoplastic resin. Diglycidyl ether of bisphenol-A (DGEBA) cured by diamino diphenyl sulphone (DDS) was used as the base resin. Polyethersulphone (PES) was used as the thermoplastic modifier. Fracture toughness and shear ductility tests were performed to characterize the materials. The fracture toughness of the DDS-cured epoxy was not enhanced by simply adding PES. However, in the presence of rubber particles as a third component, the toughness of the PES–rubber-modified epoxy was found to improve with increasing PES content. The toughening mechanisms were determined to be rubber cavitation, followed by plastic deformation of the matrix resin. It was also determined, through uniaxial compression tests, that the shear ductility of the DDS-cured epoxy was enhanced by the incorporation of PES. These results imply that the intrinsic ductility, which had been enhanced by the PES addition, was only activated under the stress state change due to the cavitation of the rubber particles. The availability of increasing matrix ductility seems to be responsible for the increase in toughness. This revised version was published online in November 2006 with corrections to the Cover Date.     

机电一体化技术在综合采煤设备中的应用与发展

介绍了机电一体化技术在国内外煤矿井下综采设备中的应用，并论述了机电一体化技术发展与相关技术的研究。     

CT引导下经皮穿刺骨骼活检时穿刺针的选择与应用

在行骨骼活检时，穿刺针的选择非常重要，甚至直接影响着活检的成功与否。笔者根据多次实践，应用环锯和Ackerman钻取外替代传统的活检方法取得了较好的效果。     

高炉鼓风机就地扩容改造方案及经济效益

介绍了利用高炉鼓风机基础实施不易地扩容改造的设计工艺方法，该方法不仅降低了设计、施工、安装费用，而且缩短了施工周期，降低了固定资产投资。     

大化水电站通航建筑物型式的再研究

本文较详细介绍了大化通航建筑的研究过程并针对大化水电站的现状，论证分析了大化水电站升船机改型为船闸的可能性，技术上的优越性和经济上的合理性，是较好的合理化建议文章。     

太阳能热风发电技术研究进展

介绍了太阳能热风发电的产生背景、技术原理和特点。太阳能热风发电能够实现由太阳能到空气动能,最终到电能的转变,具有环保无污染、运行维护简单、缓解常规能源消耗等特点。简要介绍世界上第1座试验性质的太阳能热风发电站。对太阳能热风发电技术相关研究历程从试验研究和理论研究2个方面做了综述,重点介绍了澳大利亚电站的建设进展及最新相关学术研究进展,包括过渡段理论及试验研究、系统数值模拟和太阳能热风发电技术在高山地区的应用等。介绍我国太阳能资源情况,指出我国太阳能资源丰富,适合建造大型太阳能热风发电站。     

G104-5P42分支水平井钻井液工艺技术

G104-5P42井是在高尚堡G104-5区块构造较高部位部署的一口重点开发井，也是冀东油田第一口鱼骨型水平分支井，钻探目的是开发高浅北区Ng12油层，挖掘高浅北区井间剩余油潜力。该井主井眼斜深为2388m，水平位移为736．42m，水平段长243m，第一分支斜深为2342m，水平段长120．25m，水平位移为682．14m，第二分支斜深为2421m，水平段长117m，水平位移为761．73m。三开选用无固相甲酸盐聚合醇钻井液，在钻进油气层前加入GN-YBJ-I保护剂。应用结果表明，无固相甲酸盐聚合醇钻井液具有好的防塌能力和润滑减阻效果，性能稳定、黏度、切力较低，有利于减少环空压力损耗；在油气层段密度控制在1．08g／cm^3以内，为近年来同区块密度使用最低井，减小了有害固相及滤液对储层的伤害密度，经测试该井获高产油流；该井全井平均机械钻速为15．09m／h，钻井周期比原设计提前15d。该体系的配制及维护成本较高，适宜在目的层井段使用，但可回收再利用。     

An antiplane problem of double period non-uniform crisscross distribution crack field

In this paper the antiplane problem of double period non-uniform crisscross cracks is investigated. The centers of cracks are on the tops of the isosceles triangles.Using the method of conformal mapping and elliptical function the solution in closed form has been obtained, thereby the stress intensity factor is derived.

---

Résumé Dans ce travail, on étudie le problème antiplanaire constitué par des séries de fissures non uniformes à périodicité double et susceptibles de se croiser. On suppose que les centres des fissures de deux rangées successives sont situés aux sommets de triangles isocèles.En utilisant la méthode de représentation conforme et des fonctions elliptiques, on obtient une solution sous une forme fermée, qui permet de déduire le facteur d'intensité de contrainte.

     

大透距电磁波CT法在电站坝基勘查中的应用

跨孔电磁波CT法在勘查岩溶方面大有可为。在西南某电站坝基勘查中,成功地应用了跨孔电磁波CT法,分别在左坝肩和右坝肩中所探查的二对孔间,圈出了岩溶的发育范围。所提交的资料已得到钻探、平硐勘探资料、声波和数字摄像的据互相印证。为进一步施工提供了较好的指导作用。本次勘查使用的是最新型的JW—5Q型大功率仪器和新版的处理软件,并成功地使用高频穿透98m地层,是一次很成功的应用。