SHS法陶瓷衬管的研究现状及应用前景

回顾了自蔓延高温合成陶瓷衬管的发展历史，对国内外的研究现状进行归纳总结，介绍了离心ＳＨＳ法生产陶瓷衬管的工艺特点及产品性能，展望了离心ＳＨＳ陶瓷衬管的应用前景。     

Economic Model to Optimize Underground Utility Protection

The need for better protecting our vital infrastructure from being damaged or destroyed has received increased attention since the terrorist attacks on September 11, 2001. The tragedy of having thousands of innocent people die before the eyes of an entire nation awakened people to the reality of “managed” attacks of unthinkable magnitudes. However, tragedies of a smaller scale are a daily occurrence but accepted as “collateral damage” of work in an unsafe environment. This paper presents a cost-benefit analysis to address the question of how much money should be spent in protecting underground utilities from damage. During the study of an actual incident it was found that the total costs of such accidents are vastly underreported because only costs for emergency responses and repair are tallied up. This paper makes the case that a comprehensive approach for assessing the total economic impact of such incidents on the public, business, and government is the critical stepping stone to a mathematical optimization of expenditure for damage prevention. In addition, the reader will quickly realize that the use of the presented optimization model provides theoretical underpinning for the engineering profession in its effort to better protect our critical infrastructure from terrorist attacks.     

Finite elements in the analysis of pressure vessels and piping-a bibliography (1976–1996)

The paper gives a bibliographical review of the finite element methods (FEMs) applied for the analysis of pressure vessel structures/components and piping from the theoretical as well as practical points of view. The range of applications of FEMs in this area is wide and cannot be presented in a single paper; therefore the aim of this review is to give the reader an encyclopaedic view of the differnt possibilities that exist today for the finite element analysis in the fields of pressure vessels and piping. The bibliography at the end of the paper contains approximately 1900 references to papers, conference proceedings and theses/dissertations on the subject that were published in 1976–1996. These are classified in the following categories: linear and non-linear, static and dynamic, stress and deflection analysis; stability problems; thermal problems; fracture mechanics problems; contact problems; fluid-structure interaction problems; manufacturing of pipes and tubes; welded pipes and pressure vessel components; development of special finite elements for pressure vessels and pipes; finite element software; and other topics. Also finite element software, general purpose and special purpose codes, used for the analysis of pressure vessels and pipes are briefly discussed and presented.     

基于PWM的相变热管温度分段控制系统设计

针对卫星热控制中常用的相变热管材料,设计了一个大干扰下的温度控制系统,以获得相变热管在恒温条件下的热性能参数。控制策略是将棒棒控制、模糊控制与仿人智能控制相结合,以PWM方式控制高速开关阀通断时间以控制冷却液流量大小,实现了大干扰下温度的多模式分段精确控制。提出了两点创新:将基本模糊控制改为增量式模糊控制,把误差变化率作为仿人控制的一个控制对象。实验结果表明,整个温度控制系统具有响应速度快、超调量小、调整时间短等优点,稳态误差小于0.15℃,满足实际要求。     

Adhesive bonding of stainless steel water tubing

The use of an adhesive to bond stainless steel water tubing, allowing stainless steel fittings to be employed, is considered and compared with the more conventional use of compression or capillary copper fittings together with a soft solder. Tests carried out to determine environmental effects on adhesively bonded stainless steel tubing suitable for domestic water supply, and the strengths of these joints, are described. It has been found that acrylic anaerobic adhesives are suitable for bonding tubing carrying cold water, the joints attaining superior strength to the copper-soldered ones; a reasonable degree of flexing can also be tolerated. It would appear that certain selected adhesives may also be used in joints carrying hot water.     

管道内穿管修复技术的应用

为解决城市地下金属管道由于常年连续运行时间长、防腐技术落后情况下产生漏铁、穿孔腐蚀等问题,阐述了利用管内穿管的先进技术解决地下管道的修复问题.该技术经应用后,施工质量满足使用要求,具有推广价值.     

玻璃钢管在核电站淡水输水工程中的应用

本文阐述了玻璃钢管在淡水输水工程中球墨铸铁管相比有比较明显的技术及经济优势，以及安装施工中应重视的几个问题。     

国内外塑料管材现状与发展动向

本文介绍各种塑料管材的国内外生产、消费、应用概况及发展动向。     

给水塑料管材生物稳定性快速评价方法的建立与运用

给水塑料管材的生物稳定性直接影响供水水质.建立了评价饮用水塑料管材生物稳定性的新方法(BioMig),并使用该方法评价了典型塑料管材的生物稳定性.该方法主要由迁移实验、生物膜形成实验、病原菌形成潜能和毒性评价组成.该方法具有操作简单、易于推广、灵敏度高、重现性好等优点.研究结果表明:管道材料PEX-a和PEX-c具有很好生物稳定性,而密封材料EPDM 2%却具有很高的微生物再生长潜能.除EPDM 20%外的其它管材均能支持三种病原菌的生长,其中P.aeruginosa比E.coli O157和V.cholerae在迁移水中具有更高的生长潜能.EPDM 20%具有很高的有机物释放潜能,但由于其毒性作用抑制微生物在溶液及其表面生长.     

薄壁耐热合金钢离心铸管涂料的研究

介绍了一种新的离心铸造用涂料的配制，测定了其有关性能。试验表明，它具有良好的工艺性能，抗热裂性能，绝热性能及发气量低等优点。可用于热模法离心铸造薄壁耐热合金钢管的生产。