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我国中文同类书排列书次号研究述评 总被引:5,自引:0,他引:5
In the last 40 years, more than 190 pieces of book-number research papers have been produced in China, and 25 types from 7 classes of schemes for working out book numbers were put forward. Since the August of 1990, the study of book number system has already brought into the limits of functions of the China National Technical Committee of Standardization for Information and Documentation (CNTCSID). The pressing matter of the moment is:strengthening the leadership, tackling this key problem with a collective effort,formulating as early as possible standards for appraising book numbers and finally,taking the Chinese phonetic alphabets of book number searching mixed with two or three-figure numbers of the author number as the way forward for book number system in China. 相似文献
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民族贸易是清代湘西苗疆民族交往的重要方式和有效途径.清代湘西苗疆民族贸易历经"民间自发"向"国家在场"的转变,贸易时间、地点、内容、方式等均受到官府严格的管控.清代湘西苗疆民族贸易与苗疆边墙密切相关,带有深深的"边墙格局"的印记.一方面,民族贸易集场紧密围绕边墙分布;另一方面,在以集场交易为中心的民族贸易中,边墙与集场... 相似文献
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生物柴油做为一种绿色、环保的可再生能源近年来得到了迅速的发展。本文综述了生物柴油的几种常用制备方法,如:混合法、微乳液法、高温裂解法和酯交换法等。根据选用的催化剂的不同,酯交换法又可分为均相催化法、多相催化法、生物催化法以及超临界法等。文中着重阐述了酯交换法的研究进展。 相似文献
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