引导关系实证研究—上证A股指数与上证B股指数的引导关系检验

由于我国证券市场中A股与B股产生的原因及一直以来的走势，业内人士对A、B股指之间的关系有不同的意见。本文在理论上对不同观点进行验证，对上证A、B股近两年来500个收盘指数用线性回归模型进行引导关系检验，分析检验结果认为：它们的走势之间基本上独立发展，在部分时间段存在互动关系，股指大幅波动时有A指滞后引导B指的情况，而B指滞后引导A指的情况则很少发生。     

Overshadowing of explicitly unpaired conditioned inhibition is disrupted by preexposure to the overshadowed inhibitor

In two conditioned lick-suppression experiments with rats, the interaction of preexposure to a target stimulus and subsequent overshadowing of conditioned inhibition treatment was examined. Blaisdell, Bristol, Gunther, and Miller (1998) have demonstrated that stimulus preexposure and overshadowing counteract each other in their effects on Pavlovian excitation, producing strong excitatory responding to the target stimulus. In the present experiments, a conditioned inhibition analogue of this effect was examined. Overshadowing of conditioned inhibition (i.e., attenuation of inhibitory control of behavior by the target stimulus) was demonstrated when a more salient stimulus was compounded with the target inhibitor during conditioned inhibition training. However, the overshadowing deficit was attenuated by preexposing the target stimulus prior to overshadowing treatment. To account for this phenomenon, we contrast the comparator hypothesis (Miller & Matzel, 1988) with contemporary models that focus on associative acquisition.     

Internetworking and the Politics of Science: NSFNET in Internet History

This article presents an account of the process of development of the NSFNET and its significance for the emergence of the Internet of the 1990s. The fact that the development of the interconnected system of computer networks occurred within the realm of academic research is not incidental. The dynamics of the world of scientific research were intimately related to the shaping of the network and to the way in which it spread to other sectors of society. The construction of computer networks crossed the boundaries between science and society in order to build the scientific realm by transforming the world in which it is embedded.     

Teaching Probability for Conceptual Change La Enseñanza De La Probabilidad Por Cambio Conceptual

This work presents a theoretical proposal for a methodology for the teaching of probability theory. The theoretical proposal has a dual inspiration: (1) the epistemological approach of Lakatos (1978b) regarding the quasi-empirical nature of mathematical theories; (2) the perspective of conceptual change for the teaching-learning process, as formulated by Strike and Posner (1992). The scientific content taught and the didactic methods used in the classroom should, according to this proposal, respect and conform to this dual inspiration. We also present an evaluation of the methodology in a real context: six Spanish high school classes of students aged 14–15. The main purpose of the research was to answer this question: Is our didactic proposal more effective than traditional methodology? We operatively identify the concept of traditional teaching, and establish several indicators of effectiveness: the mastery of elementary probability calculations, the quality of intuitive reasoning in probability, and the conceptual and attitudinal change produced. We found significant differences on all indicators, except for attitudinal change, in favour of the group that followed our proposal.     

Simultaneous Assembly of Multiple Test Forms

An algorithm for the assembly of multiple test forms is proposed in which the multiple-form problem is reduced to a series of computationally less intensive two-form problems. At each step, one form is assembled to its true specifications; the other form is a dummy assembled only to maintain a balance between the quality of the current form and the remaining forms. It is shown how the method can be implemented using the technique of O-1 linear programming. Two empirical examples using a former item pool from the LSAT are given—one in which a set of parallel forms is assembled and another in which the targets for the information functions of the forms are shifted systematically.     

Zum Problem der Hochschulreform in Spanien: Einige Ausgewählte Daten

Over the past ten years there has been a sweeping reform of the courses taught and qualifications awarded by Spanish universities. For that reason, an investigation was launched in 1996–97 at the University of Santiago de Compostela (in Northwest Spain) into the teaching, research and management entailed in four new degree courses: physics (years one to four), agricultural engineering (first and second years), agricultural food-processing technology (years one to three) and pharmacy. This article reports on students' opinions of the reforms in these courses, revealing dissatisfaction with facilities for practical course work, lack of connection with prospective employment, and a call for more information about courses.     

Strides Toward Equity in an Urban Center: Temple University's Professional Development Schools Partnership

Many educators believe that the goal of equity is far from being achieved given the dilemmas faced by today's inner city public schools. The authors examine the potential of Temple University's Professional Development School Partnership, a collaborative project with the School District of Philadelphia, to facilitate educational equity within an urban center. Current understandings of the construct of equity are identified and used to explore the possibilities and challenges of striving for equity in the urban center. The development of this partnership documents growth into a more inclusive, expansive, and collaborative style of working together. A closer look into this process is provided by an in-depth discussion of two essential components of the partnership, namely, its culturally responsive process and its objective of transforming the teaching and learning conditions of schools. It is argued that school systems need to look critically at their own educational resources as well as policies and practices to guarantee that they genuinely promote participation and achievement of all students. In essence we contend that there cannot be equity without the assurance that students will achieve to their fullest potential.     

History and Philosophy of Science through Models: The Case of Chemical Kinetics

The case for a greater role for the history and philosophy of science in science education is reviewed. It is argued that such a role can only be realised if it is based on both a credible analytical approach to the history and philosophy of science and if the evolution of a sufficient number of major themes in science is known in suitable detail. Adopting Lakatos' Theory of Scientific Research Programmes as the analytical approach, it is proposed that the development, use, and replacement, of specific models forms the core of such programmes.Chemical kinetics was selected as an exemplar major topic in chemistry. Eight models which have played a central role in the evolution of the study of chemical kinetics were identified by an analysis of the literature. The implications that these models have for the teaching and learning of chemistry today are discussed.     

CAD的现状及发展趋势

介绍了CAD技术的发展过程及现状,指出了CAD技术的发展趋势是智能化、集成化和网络化。     

试论信息高速公路与图书馆

信息高速公路是以计算机技术、网络通讯技术为基础,以光纤、数字卫星系统为主要信息传输载体的社会基础设施。信息高速公路将彻底改变传统图书馆信息资源的搜集、整理、加工的工艺流程、工作手段、服务方式和生存、发展空间。行驶在信息高速公路上的图书馆的现代化程度也...