Analysis of adhesively bonded CFRE composite scarf joints modified with MWCNTs

The main objective of the present work is to improve the performance of bonded joints in carbon fiber composite structures through introducing Multi-Walled Carbon Nanotubes (MWCNTs) into Epocast 50-A1/946 epoxy, which was primarily developed for joining and repairing of composite aircraft structures. Results from tension characterizations of structural adhesive joints (SAJs) with different scarf angles (5–45°) showed improvement up to 40% compared to neat epoxy (NE)–SAJs. Special attention was considered to investigate the performance of SAJs with 5° scarf angle under different environments. The tensile strength and stiffness of both NE-SAJs and MWCNT/E-SAJs were dramatically decreased at elevated temperature. Water absorption showed a marginal drop of about 2.0% in the tensile strength of the moist SAJs compared to the dry one. Cracks initiation and propagation were detected effectively using instrumented-SAJs with eight strain gauges. The experimental results agree well with the predicted using three-dimensional finite element analysis model.     

Characteristics and formation mechanism of porosities in CFRP during laser joining of CFRP and steel

An experimental investigation on the mechanism of porosity formation during the laser joining of carbon fiber reinforced polymer (CFRP) and steel is presented. The porosity morphology and distribution were characterized by optical and scanning electron microscopy, and the thermal pyrolysis behaviors were investigated by thermal analysis and designed back-side cooling experiments. The results show that there are two types of porosities in CFRP. Porosity I only appears when the heat input is more than 77.8 J/mm. It has a smooth inner wall and distributes near the bonding interface between CFRP and steel at the central area of melted zone, which is caused by gaseous products such as CO₂, NH₃, H₂O, and hydrocarbons produced by the pyrolysis of CFRP. Porosity II can be seen under all joining conditions. It has a rough inner wall and distributes far away from the bonding interface, concentrating at the final solidification locations. Porosity II is caused by the shrinkage of melted CFRP during solidification stage.     

技术性贸易壁垒对国际贸易的影响及其对策

本文介绍了国际技术贸易的原则，论述了各种对策以解决技术性贸易壁垒。     

正当防卫--运用反倾销协议维护自身权益

介绍了中国首次反倾销案的胜诉，阐述了如何正确认识倾销和如何运用反倾销。     

加入WTO后对抗旱工作的影响与策略

加入WTO后，我国农业在短期内将受到一定的冲击，使为农民和农业服务的抗旱工作带来历力。为应对入世的挑战，要抓好抗旱基础设施体系、抗旱资金投入体系、抗旱新技术推广体系、抗旱服务体系、抗旱政策法规体系建设。     

浅议加入WTO后水利行业的对策

加入世界贸易组织（WTO），既为我国加快经济社会的发展带来了机遇，同时也带来了巨大的挑战，在机遇和挑战面前，我们应当思考如何沉着应对的策略和措施，努力将机遇变成兴业的战场，把挑战变成发展的动力．作为我国国民经济和社会发展的基础设施和基础产业的水利行业，面临应对加入WTO的考验，我们究竟该做些什么和怎样去做，是应该而且必须及早作出响亮回答的．１充分认清加入WTO与加快水利行业发展的关系乃是需要解决的首要问题我国加入WTO，对于我们水利行业的干部职工来说，既是一个十分耳熟的话题，又是一个比较陌生的课题．说…     

一种新型板件连接

TOX板件冲压连接工艺是一种新的板件连接技术。作者对TOX板件冲压连接技术进行了应用研究，并取得了一些经验。主要介绍一种板件连接技术－板件冲连接工艺，较详细地叙述了其原理、应用范围及工艺要点。     

以入世为契机,进一步推进电力科研院所企业化转制

我国入世和融入经济全球化，将给中国经济运行的大环境带来深刻变化，科技事业也面临着全新挑战。电力科研所实行企业化转制，与国际接轨，按照国际规则办事势在必行。作者作为电力科研单位的一把手就电力科研院所的企业化转制阐述了个人的观点。转制必须有利于回忆科技创新和高新技术产品的开发；必须有利于抓紧培养和造就复合型人才队伍；必须有利于更好地为电网、为发供电企业提供规范化、制度化、长期化和现代化的全方位服务。     

WTO与财务软件国际化

介绍财务软件国际化的特点，指出我国财务软件要适应加入WTO的需要，必须使我国的会计准则与国际会计准则接轨，能提供符合世界上通用的国际商法、财务惯例的财务报告，具有“国际可比性”的财会信息；当前应能输出国内企业到国际资本市场融资、进行国际贸易、搞跨国投资所需的符合国际会计准则的财务报表；强调传统财务管理软件已无法适应企业管理的国际化和现代化要求，对财务软件国际化势在必行。     

发展我国制革企业刍议

中国已入世 ,制革业将拥有无限机遇 ,但制革厂还现存一些亟待解决的问题。解析了制革厂的技术创新、经营管理等方面的问题。