首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   34202篇
  免费   739篇
  国内免费   1篇
财政金融   6146篇
工业经济   2602篇
计划管理   5827篇
经济学   7863篇
综合类   393篇
运输经济   254篇
旅游经济   510篇
贸易经济   5726篇
农业经济   1702篇
经济概况   3835篇
信息产业经济   4篇
邮电经济   80篇
  2021年   216篇
  2020年   400篇
  2019年   613篇
  2018年   679篇
  2017年   721篇
  2016年   706篇
  2015年   497篇
  2014年   773篇
  2013年   3490篇
  2012年   1090篇
  2011年   1179篇
  2010年   1008篇
  2009年   1147篇
  2008年   1014篇
  2007年   987篇
  2006年   895篇
  2005年   746篇
  2004年   690篇
  2003年   698篇
  2002年   677篇
  2001年   720篇
  2000年   695篇
  1999年   606篇
  1998年   680篇
  1997年   630篇
  1996年   622篇
  1995年   539篇
  1994年   552篇
  1993年   531篇
  1992年   591篇
  1991年   578篇
  1990年   511篇
  1989年   403篇
  1988年   395篇
  1987年   439篇
  1986年   424篇
  1985年   591篇
  1984年   614篇
  1983年   572篇
  1982年   499篇
  1981年   493篇
  1980年   484篇
  1979年   489篇
  1978年   350篇
  1977年   302篇
  1976年   277篇
  1975年   278篇
  1974年   236篇
  1973年   228篇
  1972年   161篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
121.
122.
The simulation problem is one of the most commonly used formats in computer-assisted instruction (CAI). In medical education, a patient simulation problem is known as a patient management problem (PMP). A number of computerized PMP systems are currently available. However, to date, there is no record of PMP systems having been developed using artificial intelligence. This is noteworthy since artificial intelligence techniques could help in the generation of more effective and intelligent instructional systems.

This paper analyzes and evaluates existing instructional simulation software in clinical medicine in terms of effective educational design attributes. Components of effective PMP systems thus identified are incorporated into a computerized instructional system which uses artificial intelligence techniques for teaching problem-solving and diagnostic skills to undergraduate medical students.  相似文献   

123.
Human resource management (HRM) is a term which is now widely used but very loosely defined. In this paper it is argued that if the concept is to have any social scientific value, it should be defined in such a way as to differentiate it from traditional personnel management and to allow the development of testable hypotheses about its impact. Based on theoretical work in the field of organizational behaviour it is proposed that HRM comprises a set of policies designed to maximize organizational integration, employee commitment, flexibility and quality of work. Within this model, collective industrial relations have, at best, only a minor role. Despite the apparent attractions of HRM to managements, there is very little evidence of any quality about its impact. Furthermore very few UK organizations appear to practise a distinctive form of HRM, although many are moving slowly in that direction through, for example, policies of employee involvement.  相似文献   
124.
Polyhedral combinatorics is a subarea of combinatorial optimization of increasing practical importance. It deals with the application of the theory of linear systems and linear algebra to combinatorial problems. The paper is not intended as a survey on polyhedral combinatorics but it reviews some of the main concepts and proof techniques.  相似文献   
125.
Distribution-free tests for comparing several treatments with a control   总被引:1,自引:0,他引:1  
Abstract  In this paper we propose distribution-free treatments versus control tests for the one- and two-way classifications. The null distribution properties are shown to be equivalent to those of well-known statistics for which critical values have been extensively tabled. Asymptotic relative efficiencies with respect to corresponding normal theory competitors are derived and optimal designs for the allocation of experimental units to the treatments and control are obtained.  相似文献   
126.
Summary In this paper it is investigated whether robust estimation procedures for the parameters of a regression model are also applicable when the observations are generated by the errors-in-variables model. Specifically, attention is paid to bounded-influence estimators, i.e. estimators that are constructed in such a way that the influence of a single observation on the outcome of the estimator is bounded. Both the classical errors-in-variables model and models with contaminated observational errors are considered.The authors are indebted to a referee for his valuable comments on an earlier version of this paper.  相似文献   
127.
Summary The problem of estimating the slope of a linear relationship between two jointly normally distributed random variables is considered when outliers may occur in the explanatory variable. It will be studied as a special case of an errors-in-variables problem where the explanatory variable is measured which a nonnormally distributed error. In this more general model and under certain conditions a consistent estimator can be given with a normal limiting distribution. Applications to cases of outliers in the explanatory variable will be presented.  相似文献   
128.
The purpose of this study was to (a) compare the occupational sex stereotypes of 366 college students with those reported by Shinar in 1975, and (b) examine the relationships between demographic, experiential, and attitudinal variables and these occupational sex stereotypes. The results indicated a significant difference in occupational ratings from Shinar's study, with females' perceptions shifting more than males' perceptions. In addition, subjects' gender, tenure with female managers, and attitudes toward women as managers, were shown to be significant predictors of occuptational ratings. The implications of these findings for both employees and managers are then discussed.  相似文献   
129.
There is an increasing realization, world‐wide and in Southern Africa, that conservation and development are compatible.

Because human communities in the less developed rural areas are dependent on a renewable group of resources, including soil, water and forests, it is imperative that land use systems that protect these resources are introduced.

The predominance of subsistence agriculture in these areas is the most difficult syndrome of under‐development. An overall rural development strategy is required that integrates human development with resources management Where the population carrying capacity of the land has already been exceeded, a process of rapid villagization/urbanization is required. Village/urban growth and agricultural development require a carefully co‐ordinated programme of land capability analysis and planning, as well as active investment in infrastructure and the introduction of appropriate technologies and institutions.  相似文献   

130.
The impact of the brain drain on the educational systems of the countries of origin is examined, with particular reference to governmental decisions concerning education subsidies and the market for educational services. Two hypothetical cases are considered, one in which governments increase expenditures for education in the presence of a widespread brain drain, the other in which they decrease such expenditures.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号