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   15612篇
  免费   363篇
  国内免费   13篇
财政金融   2776篇
工业经济   1246篇
计划管理   2577篇
经济学   3360篇
综合类   333篇
运输经济   103篇
旅游经济   337篇
贸易经济   2810篇
农业经济   794篇
经济概况   1629篇
邮电经济   23篇
  2021年   105篇
  2020年   182篇
  2019年   277篇
  2018年   336篇
  2017年   368篇
  2016年   328篇
  2015年   231篇
  2014年   354篇
  2013年   1475篇
  2012年   419篇
  2011年   446篇
  2010年   427篇
  2009年   458篇
  2008年   507篇
  2007年   471篇
  2006年   402篇
  2005年   396篇
  2004年   346篇
  2003年   355篇
  2002年   324篇
  2001年   306篇
  2000年   308篇
  1999年   290篇
  1998年   291篇
  1997年   294篇
  1996年   305篇
  1995年   259篇
  1994年   252篇
  1993年   276篇
  1992年   267篇
  1991年   255篇
  1990年   233篇
  1989年   204篇
  1988年   176篇
  1987年   197篇
  1986年   196篇
  1985年   312篇
  1984年   303篇
  1983年   300篇
  1982年   270篇
  1981年   250篇
  1980年   230篇
  1979年   233篇
  1978年   167篇
  1977年   181篇
  1976年   149篇
  1975年   128篇
  1974年   117篇
  1973年   103篇
  1972年   74篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
Summary A sequential testing procedure called 2-SPRT for the meanμ of the negative binomial distribution with known exponentk is presented. For any fixedμ 0(μ 1<μ 0<μ 2), the 2-SPRT provides an asymptotic solution to the modified Kiefer-Weiss problem. Determination ofμ 0 such that the test provides an approximate solution to the Kiefer-Weiss problem is described. The behavior of the 2-SPRT and the Sequential Probability Ratio Test is investigated using Monte Carlo methods. The error probabilities and the average sample numbers are compared. All the computations were carried out on the Alabama Supercomputer.  相似文献   
23.
The literature on industrial organization contains very little direct evidence on the effects of actual mergers. This study estimates the effects of two recent airline mergers approved by the Department of Transportation over the objection of the Department of Justice. The merger of TWA and Ozark appears to have caused a slight increase in fares and a far greater reduction in service on city pairs out of St Louis. The merger of Northwest and Republic appears to have caused a significant increase in fares and a significant reduction in overall service on city pairs out of Minneapolis-St Paul.  相似文献   
24.
A study of the location of three classifications of high-tech industries in rural areas was undertaken using ordinary least squares, Tobit, and a two-step estimation procedure suggested by Heckman (1976). The results indicate that the location decision for high tech firms is influenced primarily by the county population, adjacency to an SMSA, and the expenditures on public infrastructure (exclusive of education expenditures). However, location near interstate highways was generally not a significant factor. Results were similar between branch and unit (single ownership) plants. Some differences in signs of orders of magnitude occurred among the estimation procedures. Making a choice between Tobit and Heckman approaches depends upon the goal of the research.  相似文献   
25.
In this article I explain why asset‐based fees are common for mutual fund management companies and why the average fee has increased recently. I argue that Securities and Exchange Commission fee regulations make alternative fee types illegal or unattractive. Management companies can maintain higher fees because regulations and brand‐name capital partly insulate them from competition and because investors cannot easily distinguish between performance‐oriented and marketing‐oriented fund companies. Index funds and unit investment trusts may offer competition to mutual funds in the future because they are designed to minimize management fees.  相似文献   
26.
Optimal investment rules are developed for a producer agency investing in domestic-market generic advertising, export market promotion, and cost-of-production-reducing research. These rules are derived assuming either maximization of producers' surplus or social surplus. The form of the optimality rules differs according to which objective is pursued. Fixed producer agency budgets are also allowed by incorporating a constraint limiting total expenditure on the three activities. Addition of such a constraint substantially alters the structure of the optimal investment rules. Differences in these rules highlight the importance of accounting for the financing mechanism when modeling optimal checkoff fund investment decisions. Optimality rules are simulated using data for the Canadian beef sector. Results suggest historic underinvestment in domestic-market generic advertising but overinvestment in export market promotion. Sensitivity of simulation results underscores the difficulty in assessing optimality of historic producer investment in cost-of-production-reducing research.  相似文献   
27.
28.
Book Review     
Books reviewed:
Ira A. Jackson and Jane Nelson, Profits with Principles: Seven Strategies for Delivering Values with Values .  相似文献   
29.
30.
Agricultural production is becoming increasingly capital and research intensive. Hayami and Ruttan, along with others, have developed and applied the metaproduction functional approach to the examination of this phenomenon on a worldwide basis. Limitations to the approach derive from a restrictive functional form chosen for estimation, and from a restrictive specification of agricultural capital and land. This study addresses those difficulties by use of the flexible translog functional form for estimation and by specifying an overall agricultural capital index and a land measure incorporating differences in the quality of land (agricultural natural resource) endowments. Estimation results indicate that agricultural comparative advantage in production is likely shifting to developed countries relative to LDC's due to capital constraints in the latter. Also agricultural potential (i.e., land endowments) do not serve to differentiate nations on the basis of agricultural production. Investment in agriculture, including land improvement, is key to the determination of comparative advantage. La production agricole fait appelle de plus en plus a beaucoup de re-cherches et de capitaux. Hayami et Ruttan, avec d'autres, ont developpe et appliqué l'approche fonctionnelle métaproduction pour examiner ce phénomena à l‘échelle du monde. Les limitations de cette approache provienneent de la forme fonctionnelle restrictive choisie pour l'estimation, et de la spécification restrictive de capitaux et terres agricoles. Cette étude traite ces difficultés en utilisant la formule “translog’ fonctionnelle adaptable pour l'estimation et en spécificant un indice du capital agricole global et une mesure de terre qui incorpore les différences du qualité des terres agricoles (ressources agricoles naturelles). Tous les résultats estimatifs indiquent que l'avantage comparatif agricole de production s'incline vers les pays développés parraport aux PMD dû aux constraintes de capitaux dans ces derniers. Aussi la capacité agricole (c'est à dire la richesse des sols) ne sert pas à différencier les nations sur le plan de production agricole. L'investissement dans l'agriculte, notamment l'amélioration de terre, est la cief pour déterminer l'avantage comparatif.  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