医用高分子材料的现状与应用

概述了医用高分子材料的发展现状及其用途,并介绍了医用高分子材料的发展动向。     

A two‐station embossing process for rapid fabrication of surface microstructures on thermoplastic polymers

An embossing strategy involving a hot station and a cold station for sequentially heating and cooling the embossing tool was investigated to reduce cycle times in hot embossing polymer microstructures. Experimental studies showed that aluminum stamps with a thickness of 1.4 mm can be rapidly heated from room temperature to 200°C in 3 s using contact heating against a hot station at 250°C. Microchannels and microlenses were successfully embossed onto high‐density polyethylene and acrylonitrile–butadiene–styrene substrates using a heating time less than 3 s and a total cycle time around 10 s. The two‐station embossing process for the microlens was also numerically studied. The simulated filling behavior agreed with the experimental observation and the predicted thermal and deformation history of the polymer offered a good explanation on the experimentally observed process characteristics. POLYM. ENG. SCI., 47:530–539, 2007. © 2007 Society of Plastics Engineers.     

纳米稀土复合固体超强酸催化合成乙酸苄酯

采用共沉淀法制备了纳米稀土复合固体超强酸SO4^2-／ZrO2-2％Nd2O3催化剂，电镜分析表明，催化剂颗粒直径在25nm左右，比表面积测定：71．03m^2／g。酸强度-12．70〈Ho〈-11．99。并对合成乙酸苄酯的最佳反应条件进行了研究。研究表明：当苯甲醇与乙酸的物质的量比为1：2，反应时间为5h，反应温度为120℃，催化剂用量为6％苯甲醇的质量时，酯化率可达92．04％。研究发现，该催化剂可重复使用并可活化再生。     

A novel shaft-less double suction mini pump

A novel double suction shaft-less mini pump was developed for heat control of small energy systems in this study.The mini pump impeller with an exit diameter of 40 mm was combined with the motor rotor supported by the hybrid dynamic bearing.The specific speed of the pump was 125 min-1 m3 min-1 m.The hydraulic performance of the pump was investigated experimen-tally under four rotational speeds.From the test results,it was recognized that the pump could provide a flow discharge of 5 L/min and head of 1.5 m,w...     

无线射频识别技术（RFID）及其在物联网中的应用

随着物联网知识的普及,以及其技术的广泛推广应用,物联网被越来越多的人所关注。本文介绍了物联网及其关键技术RFID,并结合RFID在物联网的实际应用,并对其未来的发展作出了展望。     

基于红外原理的微型多气体检测系统的设计

为了解决目前煤矿瓦斯事故以及大量使用天然气的家庭安全、环境污染等问题,设计并开发了一种具有集成化、微型化的红外多气体检测系统,通过实验数据的测试对比和数据分析,这种系统达到了微功耗、微体积、宽量程、高分辨率等技术要求,且能集成多气体检测的微型检测系统.重点介绍了红外检测的光学原理,以及从单气体检测引入到集成多气体检测的设计思想和方法,并介绍了有关CAN总线的数据传输方式和无线数据通信方式在系统中的应用.     

Damage and deterioration mechanism and curing technique of concrete structure in main coal cleaning plants

Concrete structures in main coal cleaning plants have been rebuilt and reinforced in the coal mines of the Shanghai Da-tun Energy Sources Co. Ltd., the first colliery of the Pingdingshan Coal Co. Ltd. and the Sanhejian mine of the Xuzhou Mining Group Co. Ltd. In these projects, the operating environment and reliability of concrete structures in the main plants of the three companies were investigated and the safety of the structures inspected. Qualitative and quantitative analyses were made on the spe-cial natural, technological and mechanical environments around the structures. On the basis of these analyses, we discuss the long-term, combined actions of the harsh natural (corrosive gases, liquids and solids) and mechanical environments on concrete structures and further investigated the damage and deteriorating mechanisms and curing techniques of concrete structures in the main coal cleaning plants. Our study can provide a theoretical basis for ensuring the reliability of concrete structures in main coal cleaning plants.     

数字化语音室的系统故障诊断

数字化语音实验室在学校当前语言教学中起着至关重要的作用.为了保障数字化语音实验室的设备正常高效运转,更好地为外语教学和学生学习服务,分析了数字化语音室存在的一些主要问题,总结了其常见的一些故障,就数字化语音实验室的系统故障诊断提出一些建议,可为语音室的日常管理与维护提供参考.     

地质雷达和瑞雷波检测公路工程质量技术研究

地球物理方法的应用,使公路工程质量检测技术变得更加简捷、高效和经济,能够有效缓解当前路况检测和公路工程维护所面临的压力.在介绍了地质雷达和瑞雷波探测法的基本工作原理的基础上,将这2种探测技术应用在公路工程质量检测中,详细介绍了它们对公路厚度、压实度、抗压强度、弯沉值、含水量、脱空区段等检测的具体实施方法和步骤,并指出了相关注意事项.分析认为,随着技术的更新和设备的完善,地质雷达和瑞雷波技术能够有效地应用到公路工程的质量检测过程中,有着很好的应用前景和推广价值.     

可拓集合论在专家系统知识表示中的应用

引入了可拓集合论来优化专家系统的设计过程,阐述了可拓集合论应用于专家系统的可行性,在分析知识表示的集合与分类特征的基础上,探讨了可拓集合论在知识表示中的应用,结合人工智能技术的发展趋势,对专家系统在可拓学中的应用前景做出了展望.