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   152277篇
  免费   3212篇
  国内免费   1篇
财政金融   28080篇
工业经济   12268篇
计划管理   24069篇
经济学   32679篇
综合类   1897篇
运输经济   953篇
旅游经济   2486篇
贸易经济   27722篇
农业经济   6047篇
经济概况   18415篇
信息产业经济   52篇
邮电经济   822篇
  2021年   830篇
  2020年   1615篇
  2019年   2368篇
  2018年   4628篇
  2017年   4561篇
  2016年   3925篇
  2015年   2168篇
  2014年   3464篇
  2013年   15292篇
  2012年   4615篇
  2011年   6049篇
  2010年   5452篇
  2009年   5757篇
  2008年   5331篇
  2007年   5053篇
  2006年   3602篇
  2005年   3908篇
  2004年   3554篇
  2003年   3412篇
  2002年   3079篇
  2001年   2671篇
  2000年   2584篇
  1999年   2437篇
  1998年   2292篇
  1997年   2329篇
  1996年   2193篇
  1995年   1991篇
  1994年   2010篇
  1993年   1962篇
  1992年   2035篇
  1991年   1938篇
  1990年   1809篇
  1989年   1674篇
  1988年   1587篇
  1987年   1602篇
  1986年   1695篇
  1985年   2445篇
  1984年   2292篇
  1983年   2123篇
  1982年   1976篇
  1981年   1917篇
  1980年   1871篇
  1979年   1807篇
  1978年   1631篇
  1977年   1624篇
  1976年   1389篇
  1975年   1273篇
  1974年   1183篇
  1973年   1183篇
  1972年   896篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
103.
In this paper the role of expenses in explaining closed-end fund discounts is re-examined. A present value model is developed to illustrate the relationship between expenses and discounts. Earlier studies find that discounts are not related to management fees. In this paper, using a larger sample over a longer and different period and a better specification of the expense variable consistent with the model developed, discounts are found to be significantly related to expenses. The relationship between expenses and discounts holds in the presence of other control variables.  相似文献   
104.
This paper applies principles of transition to land tenure and squatting in South Africa. Political transition in South Africa reassigned political property rights, which produced contestable, and rent‐seeking incentives for squatting as a means to privatize land and redistribute wealth. Government failure to establish and protect private property rights in a squatter camp resulted in common‐pool problems that resisted private and public resolution with consequent rent dissipation and social loss. In response to this retreat from duty, informal agents emerged to claim their own share of the prize. Without enforceable rules of capture, the growth of squatter camps in South Africa will continue. JEL classification: D7, H8, K1, K4, R1, R4.  相似文献   
105.
106.
The rise of environmentalism in the past decade has become a major transforming force in pollutive and hazard prone industries. Corporate environmental responsiveness is not simply a peripheral and one of the many ‘social’ or ‘ethical’ issues facing business. It is becoming a central concern for competitiveness, productivity, and profitability. It is creating strategic transformation of companies in a diverse range of industries such as, Autos, Chemicals, Oil, Fast Foods, Power Generation, Pharmaceuticals, etc. The process of environmentally directed self-renewal, called ‘greenewal’ here, affects all aspects of companies. It implies changes in products, production systems, waste management practices and internal systems. It seeks to make companies simultaneously more competitive and environmentally responsible. This paper describes the pressures of and responses to environmentalism in a selected set of industries. It examines the processes of greenewal that companies are undergoing. It identifies implications for strategic greening of firms.  相似文献   
107.
The linkage between macroeconomic policies and agricultural commodity trade has become an important research issue of agricultural economists. This paper investigates the macroeconomic linkage of soybean trade competition between the exporting countries of the United States, Brazil, and Argentina in the EC-12 and Japan import markets. It is argued that U.S. monetary growth may have important impacts on the competitive position of U.S. soybean exports through exchange rates. Two relationships are investigated: (a) the effects of U.S. monetary growth on the agricultural trade weighted exchange rates, and (b) the responsiveness of agricultural commodity prices and U.S. exports to exchange rate movements. Results indicate that a weak dollar increases imports of soybeans and soymeal significantly which serves to increase the equilibrium world price and increase both U.S. and Brazil/Argentina exports in the long run. However, during periods of more expansionary U.S. monetary policy there is little evidence of significant increases in market share position for U.S. soybeans and soymeal in world markets.  相似文献   
108.
Medic (Medicago spp.) pastures are widely grown in rotation with dryland cereal crops in Mediterranean climate zones of Australia. Attempts since the 1960's to introduce this system to Mediterranean west Asia and north Africa (the native region of medic) have not lead to significant adoption; farmers in the region recognize medic, but as a weed and natural pasture plant. This first detailed economic evaluation of the rotational medic system was conducted using a whole-farm linear programming model based on the agricultural system of north-west Syria. The model represents in detail impacts of rotation on yields, labor requirements of alternative farm activities, availability of family and hired labor, subsistence income requirements, livestock feed sources and uses at different times and a choice of sheep stocking rates. Biological data for the analysis are based on a large six-year cropping and grazing experiment near Aleppo on terra-rossa soil with rainfall mainly in winter and averaging about 330 mm annually. The trial compared a dryland medic-wheat system and traditional two-year rotations of wheat with: fallow, watermelon, lentil and vetch. Results indicate that, given current prices and yields from the trial, medic is less profitable than traditional rotations. The model was used to investigate situations in which medic would be economically preferred. Selection of a medic rotation by the model was found to be particularly sensitive to the area of the farm and the price of labor. On small farms, labor availability per hectare is high, favouring the production of labor intensive crops such as lentil and watermelon. On larger farms, labor costs of these enterprises are substantial, increasing the relative profitability of medic, especially if labor prices increase. Interestingly, the relative desirability of medic is more sensitive to its impact on subsequent wheat crops than to the level of pasture production. We also found that modest increases in the prices of sheep products (especially milk) have a major impact on the economic performance of medic. These insights will allow improved focusing and targeting of future research and extension activities.  相似文献   
109.
Extensification of agriculture is one of the major factors contributing to the destruction of forests in Africa. In Sudan, such horizontal expansion comes at the expense of land devoted to trees and other vegetation, thereby inducing conditions that are inimical to sustainable agricultural production. Different factors have contributed to extensification. Although high economic returns from crop (mainly sorghum) production was an important factor encouraging extensification of rainfed mechanized farming, other factors outside agriculture have also contributed to that expansion. This paper uses data from eastern Sudan and an acreage response model, to identify the most important factors influencing acreage expansion. Different measures and forms of risk were used in the acreage response model. The paper shows how policies in the energy sector can indirectly influence acreage expansion in the agricultural sector.  相似文献   
110.
This article reviews the law regarding Title VII employment discrimination protection from religious discrimination. The issues surrounding the principal legal protection in this regard are explored in the context of a recent controversial case in which an author, Forrest Mims, was not hired as a regular contributor forScientific American magazine, ostensibly because of his belief in the theory of creation over the theory of evolution. The definition of what constitutes a protected religious belief or practice is seen to have expanded over time. However, a belief in creationism is not necessarily seen as being tantamount to a religious belief under present legal interpretation of Title VII. The implications of this finding for future needed Title VII revision are discussed.  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