浅谈高等院校双语教学

文章介绍了双语教学的内涵和各国双语教学发展现状。认为我国高等院校双语教学主要存在缺乏合格师资、学生对双语教学的接受能力较差、缺乏双语教材和对双语教学认识上存在误区四个方面的问题，并针对这些问题提出了相应的对策。     

Polynomial approximation of nonlinear regression functions

In the present paper a nonlinear regression function is approximated by a polynomial estimator according to the expectation of the quadratic L ²-distance as risk is given. For special experimental designs with repeating experimental points this estimator coincides with the estimator by the method of the reproducing kernel.

Considerations about the relation for the sample size and the degree of the approximation polynomial and about the quadratic mean are given.     

完善高校民主管理的思考

针对目前高校管理中存在的主要问题：思想认识不到位、制度建设不完善、缺乏有效的监督机制等,提出了确立以人为本的理念,提高民主管理能力,建立民主决策和民主监督机制等对策措施。通过这些措施的有效实施,完善高校民主管理。     

关于半无界弦振动问题的解

对半无界弦振动问题给出一个较强的结果     

Inverse Problems of Matroid Intersection

In this paper we study the inverse problem of matroid intersection: Two matroids M ₁ = (E, ₁) and M ₂ = (E, ₂), their intersection B, and a weight function w on E are given. We try to modify weight w, optimally and with bounds, such that B becomes a maximum weight intersection under the modified weight. It is shown in this paper that the problem can be formulated as a combinatorial linear program and can be further transformed into a minimum cost circulation problem. Hence it can be solved by strongly polynomial time algorithms. We also give a necessary and sufficient condition for the feasibility of the problem. Finally we extend the discussion to the version of the problem with Multiple Intersections.     

An Approximation Algorithm for Alignment of Multiple Sequences using Motif Discovery

Given a set of N sequence, the Multiple Sequence Alignment problem is to align these N sequences, possibly with gaps, that brings out the best commonality of the N sequences. The quality of the alignment is usually measured by penalizing the mis-matches and gaps, and rewarding the matches with appropriate weight functions. However for larger values of N, additional constraints are required to give meaningful alignments. We identify a user-controlled parameter, an alignment number K (2 K N): this additional requirement constrains the alignment to have at least K sequences agree on a character, whenever possible, in the alignment. We identify a natural optimization problem for this approach called the K-MSA problem. We show that the problem is MAX SNP hard. We give a natural extension of this problem that incorporates biological relevance by using motifs (common patterns in the sequences) and give an approximation algorithm for this problem in terms of the motifs in the data. MUSCA is an implementation of this approach and our experimental results indicate that this approach is efficient, particularly on large numbers of long sequences, and gives good alignments when tested on biological data such as DNA and protein sequences.     

我国应尽快解决“候鸟式”移动问题

"候鸟式"移动是我国近年一段时间内不可逆转的必然趋势,是一种我国特有的制度型、过渡型迁移现象.它在为农民、城市和整个社会带来很大的发展机遇的同时,由于不稳定的状态,也带来了诸多不良的影响.今天,从政策、户籍、法律上和社会保障等多方面,合理解决"候鸟式"劳动力的就业、生活各方面的情况和问题,并尽快将"候鸟式"转化为"永久式"移动,是我国解决农村流动人口问题的一项艰巨而迫切的任务.     

问题意识与文学理论的危机--危机中的文学理论之重建

学术界关于"文学理论危机"的讨论十分热烈."危机论"的出现反映了我们对文学理论繁荣的期待和憧憬,文学理论的危机表现在理论和实践的各个层面.究其原因,文学理论的危机与批评家和理论家缺乏问题意识密切相关,强化问题意识是克服危机的重要方法.     

近代中国知识分子思想转型问题研究

近代中国知识分子的思想转型是将前近代时期士大夫的生命形态作为参照系的,该参照系的主要内容是士大夫在政治上的最高理想为充当帝师王佐,功名意识乃普遍的价值观念,经济观念核心是重农抑商,并进而形成文化优越感、保守拒变心态、"夷夏之辨"的世界观,且陷入空疏无用的"学问"之争中不能自拔,于社会民生毫无裨益。近代中国知识分子思想转型集中体现在三个方面:政治方面,带有悲剧、迷茫色彩的忧患意识;经济方面,以重科技发展实业为核心的经济意识;文化方面,中西地位反向互换的文化意识。这种作为一种质变过程同时更多地体现为量的累积的转型乃是一条痛苦而漫长的人生旅路。     

Peer effects on substance use among American teenagers

The widespread use of illicit substances by American teenagers has attracted the interest of both the general public and academic researchers. Among the various factors that people believe influence youth substance use, peer effects are identified as a critical determinant. Identifying peer effects, however, is known to be a difficult task. In an attempt to overcome known difficulties, I estimate peer effects on substance usage among American teenagers using perceived peer behavior in the National Longitudinal Survey Youth 97. The data indicate robust peer effects. Moreover, the results do not change substantially in school and household fixed effects estimations.This is a chapter of my Ph.D. dissertation submitted to Michigan State University. I am especially grateful to David Neumark for his constructive comments and continuous encouragement. I thank Jeff Biddle, Ali Berker, Frederic Durousseau, Gigi Foster, Daniel Hamermesh, John Strauss, Jeffrey Wooldridge, the participants in the labor economics workshop at Michigan State University and 2001 Joint Statistical Meeting, and an anonymous referee for helpful comments. Scott Adams and David Wetzell gave me detailed comments, as well as advice on English. Donna Maurer provided careful editorial assistance. All remaining errors are, of course, my own. Due to a confidentiality agreement with the BLS on the usage of the NLSY 97 GeoCode file, the part of the dataset that is constructed from the GeoCode file cannot be released. Responsible editor: Daniel S. Hamermesh