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   36455篇
  免费   711篇
  国内免费   1篇
财政金融   6957篇
工业经济   2695篇
计划管理   6025篇
经济学   8217篇
综合类   422篇
运输经济   223篇
旅游经济   588篇
贸易经济   5911篇
农业经济   1634篇
经济概况   4422篇
邮电经济   73篇
  2021年   217篇
  2020年   361篇
  2019年   511篇
  2018年   660篇
  2017年   650篇
  2016年   644篇
  2015年   493篇
  2014年   717篇
  2013年   3565篇
  2012年   1000篇
  2011年   1095篇
  2010年   903篇
  2009年   1044篇
  2008年   1106篇
  2007年   1010篇
  2006年   928篇
  2005年   893篇
  2004年   871篇
  2003年   858篇
  2002年   793篇
  2001年   758篇
  2000年   761篇
  1999年   654篇
  1998年   679篇
  1997年   635篇
  1996年   632篇
  1995年   572篇
  1994年   616篇
  1993年   609篇
  1992年   582篇
  1991年   589篇
  1990年   539篇
  1989年   452篇
  1988年   458篇
  1987年   471篇
  1986年   483篇
  1985年   710篇
  1984年   659篇
  1983年   669篇
  1982年   599篇
  1981年   535篇
  1980年   515篇
  1979年   529篇
  1978年   465篇
  1977年   447篇
  1976年   350篇
  1975年   332篇
  1974年   292篇
  1973年   288篇
  1972年   227篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
141.
142.
Determinants of internal and external R&D: Some Dutch evidence   总被引:1,自引:0,他引:1  
Summary Innovating firms can choose to engage in either internal or external R&D, or in both. In the current study, we shall examine internal and external R&D separately to determine empirically the market structure characteristics explaining the external R&D share and the differences in market structure determinants between internal and external R&D. Our results indicate that a government policy that aims at stimulating technological progress by offering external research facilities is particularly interesting for smaller, capital-intensive firms operating in less concentrated markets.We would like to thank Alfred Kleinknecht for providing the R&D data and Kees Bakker and Yvonne Prince for providing the market structure data. We thank Alfred Kleinknecht, Bart Nooteboom and an anonymous referee for their comments and suggestions We acknowledge a research grant from the Stichting KMO Fonds.  相似文献   
143.
144.
145.
146.
147.
The new constitutional dispensation will stimulate development activities for the Coloureds and Indians through community development and basic needs programmes which are mainly categorised as “own affairs”.

Local governmental institutions will become important additional instruments in this respect. The development backlog of Coloureds and Indians and its implications is sketched and the expectation is expressed that the dynamics of the new situation will lead to greater public expenditure for these needs. However, political demands for the realisation of development goals could outpace societal progress in terms of community development approaches, while the demographic distribution of Coloureds an Indians militates somewhat against their optimal drawing of benefit from decentralisation policies.  相似文献   

148.
I have argued that for the period from 1661 to 1850, patent data in England were consistent in that no official changes in methods and standards of issuance occurred. Book data on titles published on farming production methods were similarly consistent from 1523 to the mid-19th century because the market for books developed gradually and the technology of printing was not substantially changed until the mid-19th century.My main point is that data on output of titles of books on farming productive techniques in England are useful measures of technological change. Books did have information on good production methods and could express productive ideas where a patent may not be issued. Further, the literacy rate of farmers was high so that books were likely an important source of ideas on farming production methods. Finally, the fluctuations in the book data were highly related to the fluctuations in the patent data, suggesting that a common set of factors caused those fluctuations. The high correlations between the detrended book and patent data indicate that if we accept patenting as a useful measure of technology we may also accept book title output of a technical nature as a good measure of technical change.I used the data for a simple analysis of the trend growth rate of agricultural technology in England from 1551 to 1850. While there is limited evidence to show that the subperiod 1651–1750 saw a slowing in the trend of development of farming technology, I argue that a division of the entire period into subperiods is too simplistic. A more fruitful approach would be an analysis of the underlying forces that determined the trend of development of the technology of English agriculture.The next step is an analysis of the forces that influenced technological development of English farming. From an economic point of view, market forces play an important role in influencing technology. Because such an analysis deserves careful consideration, I leave that to another paper (see Sullivan and Simon, 1983).  相似文献   
149.
A 1st step is taken in this discussion towards the explicit theoretical recognition that fertility decisions are made by pairs of individuals who conceivably have different preferences or are in different circumstances. The focus is on disagreements between spouses over desired family size. The discussion begins by identifying the costs and benefits of child services to each spouse, which involves consideration of the type of interdependency of the utility functions as well as the nature of the externality problem in the production of child service. Specific examples are included of situations in which disagreement is likely to occur. Using the National Fertility Survey of 1965, it is possible to test whether disagreements are more likely to occur in these identified cases. 2 types of fertility conflict are predicted: the wife desires fewer children than the husband and the reverse. The National Fertility Survey (NFS) data set contains 5617 interview records. A sample of 1559 women who were married once, husband present, nonmenopausal, aged 25-39 with valid answers to all questions were selected. Husband's schooling in excess of wife's increased the probability that conflict of the husband demanding fewer children type will arise and the probability was increased at higher levels of income. The demand for quality rose with income and placed additional pressure on a husband with more education to assist (via lost leisure time) in the creation of quality. The effects were highly nonlinear. Higher levels of status of the wife's (potential) job had the predicted effect of making wife demands fewer children conflict more likely, but only through intermediate levels of status. Another variable which had a significant influence on the probability of conflict was the husband's age, with higher husband's age leading to husband demanding fewer children than wife conflict.  相似文献   
150.
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