第四代移动通信（4G）的技术分析与发展前景

文章介绍了第四代移动通信的概念,主要应用的技术以及4G的发展前景.     

The duration of unemployment in Russia

This paper uses longitudinal survey data to assess factors affecting the duration of unemployment in Russia. We examine four types of marginalised labour force participants, according to ILO guidelines and survey responses, and we estimate duration models for each type. It turns out that the sets of characteristics with the strongest effects on the duration are remarkably similar across the different unemployment definitions and model specifications. Therefore, despite the formidable practical measurement problems, problematic groups of individuals can actually be identified. Received: 27 January 1999/Accepted: 27 January 2000     

大学生考试作弊现象分析及对策

考试是对教学效果的检验 ,是对大学生掌握科学知识程度的检验 ,而考试作弊现象则严重影响了这种检验的真实性 ,不利于合格人才的培养。对大学生考试作弊现象进行认真的分析和研究 ,采取的对策是十分必要的     

五四时期中国人民对社会主义的认识

文章从分析近代中国社会基本矛盾入手 ,阐明了中国人民选择社会主义的原因 ,揭示了在中国实行社会主义制度是历史发展必然规律。这对我们坚定不移地走社会主义道路具有现实意义     

略论刘少奇对党建理论的突出贡献

本文从党的建党路线、党的群众路线、党的民主集中制、党性和党风等方面 ,阐明了刘少奇对党建理论的突出贡献。     

高校"两课"教改目标实行"4 y"课程体系探讨

依据国务院、中宣部和教育部《关于进一步加强和改进大学生思想政治教育》的文件精神,结合我国普通高校"两课"教学与改革实际,提出把"4 y"课程体系锁定为各高校"两课"教改整体目标的明确主张。这对统一各高校"两课"教学思想与课程设置;降低各高校"两课"教学的教育成本;减轻高校学生学业负担,更好地适应国家与社会,特别是研究生入学考试对高校毕业生所应储备的相关政治理论知识与思想道德品质的实际需求等具有现实意义。     

Sr2CeO4荧光粉的制备与发光性能研究

以铈、锶的碳酸盐与柠檬酸为原料用改良柠檬酸-凝胶法合成了Sr2CeO4荧光粉,用荧光光谱(PL)检测Sr2CeO4的发光性能.实验研究发现,用改良柠檬酸-凝胶法合成的Sr2CeO4荧光粉具有宽带光谱,发射光谱的最大峰位于467 nm;研究还发现,恰当的焙烧温度,加入少量硝酸铵有利于获得发光亮度高的Sr2CeO4粉末.     

A study of BIB designs through support matrices

This paper deals with the existence and nonexistence of BIB designs with repeated blocks. The approach is an algebraic one. The concept of a support matrix is introduced and some of its basic properties are noted. Some basic examples of support matrices are given when the block size is 3. The connection between full column rank proper support matrices and irreducible designs is explored and some examples of such matrices are given.     

Some new factor screening designs using the search linear model

Factor screening designs for searching two and three effective factors using the search linear model are discussed. The construction of such factor screening designs involved finding a fraction with small number of treatments of a 2^m factorial experiment having the property P_2t (no 2t columns are linearly dependent) for t=2 and 3. A ‘Packing Problem’ is introduced in this connection. A complete solution of the problem in one case and partial solutions for the other cases are presented. Many practically useful new designs are listed.     

Pb02与Mn2+反应趋势的探究

以实验为基础,对PbO2与Mn2+的反应进行了研究,其结果表明在酸性溶液中强氧化剂PbO2氧化Mn2+的主要产物为MnO4-,反应物浓度、温度及酸度等反应条件是影响反应自发进行方向的重要因素,作者还运用化学热力学方法进行了讨论,从理论上阐明了反应趋势与酸度、温度的关系.