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   134387篇
  免费   3792篇
  国内免费   2篇
财政金融   25536篇
工业经济   11194篇
计划管理   21730篇
经济学   29084篇
综合类   1461篇
运输经济   965篇
旅游经济   2490篇
贸易经济   22647篇
农业经济   6115篇
经济概况   16715篇
信息产业经济   7篇
邮电经济   237篇
  2021年   839篇
  2020年   1626篇
  2019年   2380篇
  2018年   2293篇
  2017年   2486篇
  2016年   2681篇
  2015年   2083篇
  2014年   3393篇
  2013年   15282篇
  2012年   4203篇
  2011年   4150篇
  2010年   3714篇
  2009年   4328篇
  2008年   3892篇
  2007年   3272篇
  2006年   3597篇
  2005年   3557篇
  2004年   3118篇
  2003年   2873篇
  2002年   2862篇
  2001年   2611篇
  2000年   2528篇
  1999年   2442篇
  1998年   2284篇
  1997年   2321篇
  1996年   2183篇
  1995年   1992篇
  1994年   2015篇
  1993年   1965篇
  1992年   2036篇
  1991年   1833篇
  1990年   1708篇
  1989年   1564篇
  1988年   1503篇
  1987年   1517篇
  1986年   1600篇
  1985年   2364篇
  1984年   2259篇
  1983年   2068篇
  1982年   1923篇
  1981年   1904篇
  1980年   1877篇
  1979年   1791篇
  1978年   1595篇
  1977年   1589篇
  1976年   1352篇
  1975年   1244篇
  1974年   1168篇
  1973年   1154篇
  1972年   869篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
951.
952.
A method of combining survey data and Dairy Herd Improvement Association (DHIA) records to achieve low cost farm trials is presented. Farm trials and surveys of current practices and production responses are useful to identify yield gaps between expectations predicted from experimental findings and actual field results. Different management schemes can be ranked using subjective probabilities and stochastic dominance to enhance successful implementation of research findings and to increase the feedback between researchers, extension workers, and producers. A survey of current masitis control practices and expected milk yield response is the example. Combining survey results with DHIA records allowed estimating the relationship between somatic cell counts (SCC) and milk yield. Eliciting beliefs about the relationship between SCC and milk yield showed that producers agreed with predictions from the statistical model. Subjective probabilities about SCC and mastitis control practices showed that our sample of experts and producers consistently ranked the different practices but extension agents had no consensus about the the most or least effective ones.  相似文献   
953.
This study examines the effect of initiating discount and no discount dividend reinvestment plans on shareholder wealth. The results show a negative response to DRP announcements, which is significantly smaller than that found in studies of new equity offerings. These results are consistent with the Scholes and Wolfson (1989) hypothesis that managers in need of equity capital use DRPs to mitigate the adverse stock price effects of new equity issue announcements. Furthermore, there is a significant difference in the price response of discount and no discount DRPs for industrial firms. This result is supportive of the signaling potential of discount DRPs. Supportive evidence is also found in the analysis of firm characteristics for industrial firms.  相似文献   
954.
The degree of spatial market integration in European Community agricultural product markets is investigated. The methodology is based on co-integration analysis. A two-step testing procedure is applied to test the existence of the ‘Law of One Price’ which should be in force if these markets are truly integrated. The results show that market integration has not been achieved in a number of cases even when MCAs are subtracted from the price series used.  相似文献   
955.
For a compound Poisson process with negative drift and jump distribution consisting of a mixture of exponentials on [0) and on (-, 0), an exact expression is derived for the probability of hitting the level c, c > 0. the problem is motivated by modeling the returns from trading on financial markets.  相似文献   
956.
Time-Based Management of the New Product Development Process   总被引:3,自引:0,他引:3  
This study explored the problem of compressing new product development by focusing on the specific phases of the innovation process. These phases manifest significant qualitative differences that require attention for understanding the complexities of accelerating new product development. Based on data from 35 high-technology companies, Necmi Karagozoglu and Warren Brown identified several different acceleration methods. Results revealed unexpected and at times inconsistent insights than those reflected in the case study and anecdotally based literature, and implied also that some of the well documented approaches to successful new product development need to be replaced with their time-based versions.  相似文献   
957.
958.
959.
Borda's vote method was used by the French Academy from 1796 to 1803 when Napoleon got it abolished. In the laws and regulations of the Academy there are stipulations regarding the election of new members. The practice is demonstrated by some examples from the protocols. In fact, Borda presented two vote methods which he showed would give the same conclusion. The method which has not been in the limelight proves to be the same one as is used for selecting the best player in chess tournaments.  相似文献   
960.
This article discusses changes in approach to the study of business relationships, and sees the paradigm concept as constituting an inadequate basis for describing gradually evolving changes in the perception of business. The frequent references to paradigms appear to focus more on state aspects than on change aspects of theory building. The article attempts to trace some of the changes in the perception of markets preceding the emergence of network theories, and relates the presence of an interactional approach to business studies to the concept of problem shifts (Lakatos). The development of interactional approaches in marketing is seen as representing a shift away from theory building commonly found in economics and organizational theory. Changes in the approach to the study of business relationships are interpreted as theoretical or empirical problem shifts, and are thus related to the a priori and a posteriori relevance of the continual evolution of alternative business theories. The article explores some of the epistemological relevance of the network theories to the study of market relationships, and the potential impact on continual changes in approach to the study of markets.  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