研究了Al-5Ti-B细化剂的类型、加入量和精炼工艺对ZL205A合金组织性能的影响.结果表明,Al-5Ti-B细化剂中TiB2相聚集分布时,会诱发细化效果的不均匀性,细化剂中的粗大Al3 Ti相会残留于合金基体中,降低合金的力学性能;Al-5Ti=B细化剂在Ti加入量为0.25％时,ZL205A合金的细化效果良好且力学性能最佳,屈服强度、抗拉强度与伸长率分别可达378MPa、455MPa和8.9％;采用C2Cl6精炼时,细化剂中的TiB2颗粒会发生“中毒”现象,加剧TiB2相的聚集.采用氩气精炼并控制静置时间可以保证TiB2相的稳定性.

Carbon nanotubes have been considered as an ideal reinforcement for polymer composites owing to their outstanding mechanical,electrical,optical and magnetic properties.Elastic modulus is an important pa-rameter of mechanical properties of materials.The research progress of the study of the elastic modulus of car-bon nanotubes reinforced polymer composites was reviewed in this paper.Different method of predicting the elastic modulus of carbon nanotube/polymer composites,rule of Mixtures,Hashin-Shtrikman model,Cox model Halpin-Tsai model and numerical simulation were introduced.In addition,the problems and the develo-ping prospect in this field were discussed and previewed.

This study examines the nature of municipal household waste sorted reclaiming in China. This finding indicate conceptual lag, lack of study and the degree of economic development are the main baffle in the implement of municipal household waste sorted collection policy. This study discussed the successful experience of municipal waste sorted reclaiming in Japan.

The gross quantity of urban garbage in China is increasing year by year.But,the garbage disposal is still mainly left in piles on exposed yards or buried underground thus bringing about the problems such as pollution due to garbage,waste of resources and shortage of land area for garbage burying.The best way to solve the problems is garbage sorting/recovery.The main reasons why the garbage sorting/recovery process is so difficult to implement in China are the out-of-date ideas,lack of theoretical/practical investigation relevant to the process and deficiency of governmental efforts to do that.In this respect Japanese accumulated plentiful experience including the national policy of urban garbage disposal by sorting/recovery,complete statistical data provided by local governments,feasible cut target in unexecution and the systematic and careful education.All of these are the lessons to be learned by the governments in China.

区域技术发展作为国家创新系统的一个层次,对于每个国家和地区的经济发展都具有重要的影响.本文从技术创新环境的角度,讨论了随着技术与经济的发展,在区域技术发展这个层次上政府职能的转换,及在老工业区向"技术区域"转换的过程中,地方政府的作用.

本文从工业系统发展的视角出发,研究了工业系统生态化的背景、目标和特征,最后通过分析共同知识规则的建立、制度演化的路径依赖、技术行为多样性和组织模式创新的动因四个方面,揭示了工业生态化演进的制度变迁机制.