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.     

TRT入口方管道爆裂原因剖析

介绍了鞍钢7#高炉TRT装置入口方管道爆裂事故经过,进行了原因分析,并提出了解决措施。     

新一代银行大型机网络接入技术研究

银行大型机网络接入技术的转型是当前一个非常重要的研究与应用课题。文章在成功实现银行大型机网络接入技术转型的基础上,分析了相关新技术,解决了转型中的关键问题,提出并实现了一种稳定高效的银行大型机网络接入技术方案,对银行大型机网络接入技术的转型具有指导意义,对银行信息化技术研究具有重要参考价值。     

中国的主要水问题及水文学的机遇

从水资源开发利用与保护、水旱灾害防治等方面论述中国当前存在的主要水问题：水危机和水浪费同时存在、水污染日趋严重、防洪减灾任重道远、生态环境破坏严重、全球气候变暖产生不利影响；进而论述水文学研究面临的新课题：水文现象的不确定性、人类活动对水文的影响、水位频率计算、水资源开发利用的最佳效应、水资源供需分析、农业节水灌溉机理及水旱灾害的防治，并指出必须加强对这些新课题的研究     

超速状态的"混乱"呈现--2005首届深圳城市\建筑双年展评述

文章从“展览描述”、“展览性格分析”、“展览学术分析”三个层面对张永和作为独立策展人的首届深圳“城市＼建筑”双年展进行解读与剖析。     

大空域机动巡航导弹的模糊PID控制器设计

针对大空域机动巡航导弹下降转平飞过程中出现的强非线性特点．在俯仰通道设计了模糊PID双模控制方案。以高度误差和该误差变化量为输入．以高度误差为阀限．在高度误差较大时采用响应迅速的模糊控制器．较小时采用稳态精度较高的PID控制器。最后通过仿真表明通过该方案所控制的弹道符合方案弹道．满足设计指标要求。     

均衡营养早餐的研制

根据膳食营养的要求,以燕麦、爆裂玉米、奶粉、鸡胸肉、胡萝卜和香菜为原料,采用微波技术和冷冻干燥技术生产均衡营养早餐,确定了最佳的配方为燕麦片15g、爆裂玉米8g、奶粉10g、鸡肉丁5g、胡萝卜丁0.5g、香菜干0.5g、盐或糖1g.     

基于S-CDMA的HFC上行信道接入协议性能仿真分析

讨论了基于S－CDMA的HFC网上行信道的高效接入协议－SAMA，提出了双信道接入机制的工作原理，并对系统性能进行了分析与计算机仿真，得到一些有意义的结论。     

Formation of low-resistivity poly-Si and SiNx films by Cat-CVD for ULSI application

In this paper, bulk-Si metal–oxide–semiconductor field effect transistors (MOSFETs) are fabricated using the catalytic chemical vapor deposition (Cat-CVD) method as an alternative technology to the conventional high-temperature thermal chemical vapor deposition. Particularly, formation of low-resistivity phosphorus (P)-doped poly-Si films is attempted by using Cat-CVD-deposited amorphous silicon (a-Si) films and successive rapid thermal annealing (RTA) of them. Even after RTA processes, neither peeling nor bubbling are observed, since hydrogen contents in Cat-CVD a-Si films can be as low as 1.1%. Both the crystallization and low resistivity of 0.004 Ω·cm are realized by RTA at 1000 °C for only 5 s. It is also revealed that Cat-CVD SiN_x films prepared at 250 °C show excellent oxidation resistance, when the thickness of films is larger than approximately 10 nm for wet O₂ oxidation at 1100 °C. It is found that the thickness required to stop oxygen penetration is equivalent to that for thermal CVD SiN_x prepared at 750 °C. Finally, complementary MOSFETs (CMOSs) of single-crystalline Si were fabricated by using Cat-CVD poly-Si for gate electrodes and SiN_x films for masks of local oxidation of silicon (LOCOS). At 3.3 V operation, less than 1.0 pA μm⁻¹ of OFF leakage current and ON/OFF ratio of 10⁷–10⁸ are realized, i.e. the devices can operate similarly to conventional thermal CVD process.     

非晶金刚石离子镀膜机自动化控制系统的设计

结合非晶金刚石离子镀膜机的工艺特点和要求,介绍了一种成功应用的分布式控制系统的设计,重点讨论了控制系统的硬件配置、软件设计、通信服务程序以及软件编程中的几个控制算法.