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   8752篇
  免费   143篇
财政金融   1860篇
工业经济   640篇
计划管理   1370篇
经济学   1850篇
综合类   113篇
运输经济   53篇
旅游经济   166篇
贸易经济   1374篇
农业经济   309篇
经济概况   1147篇
邮电经济   13篇
  2020年   78篇
  2019年   123篇
  2018年   156篇
  2017年   169篇
  2016年   148篇
  2015年   111篇
  2014年   153篇
  2013年   978篇
  2012年   227篇
  2011年   254篇
  2010年   226篇
  2009年   238篇
  2008年   229篇
  2007年   177篇
  2006年   194篇
  2005年   170篇
  2004年   171篇
  2003年   169篇
  2002年   174篇
  2001年   163篇
  2000年   162篇
  1999年   154篇
  1998年   166篇
  1997年   160篇
  1996年   149篇
  1995年   119篇
  1994年   124篇
  1993年   139篇
  1992年   159篇
  1991年   159篇
  1990年   114篇
  1989年   114篇
  1988年   96篇
  1987年   112篇
  1986年   120篇
  1985年   159篇
  1984年   139篇
  1983年   164篇
  1982年   137篇
  1981年   123篇
  1980年   140篇
  1979年   125篇
  1978年   94篇
  1977年   108篇
  1976年   101篇
  1975年   101篇
  1974年   91篇
  1973年   73篇
  1972年   62篇
  1971年   62篇
排序方式: 共有8895条查询结果,搜索用时 0 毫秒
91.
92.
93.
EFFECTS OF PRICE AND AVAILABILITY ON ABORTION DEMAND   总被引:1,自引:0,他引:1  
Over 1.5 million legal abortions were performed in the United States in 1988. State-level regulation affecting the price or availability of abortion services may expand given recent Supreme Court decisions. This paper uses state-level data pooled over time to estimate abortion demand. Using single cross-sections of state data, past studies find abortion demand per 1,000 pregnancies to be price inelastic and find income elasticity to be positive and significant. The analysis here shows that price elasticity estimates in a single cross-section are sensitive to the choice of state characteristics used to control for "abortion attitudes" within a state. Ajixed-efects model design with pooled data gives more robust abortion demand price elasticity estimates. The results suggest that any new state regulations that increase the costs of obtaining abortions will reduce abortion use and increase unintended fertility .  相似文献   
94.
The necessity of entering a sequence of interrelated state primaries has forced presidential candidates to be much more deliberate in planning campaign finances. This paper presents a linear programming model for optimal allocation of time and money to each primary in order to maximize the number of delegates won. The model attempts to quantify and exploit the relationships between performance in early primaries and performance in later primaries, which has heretofore been labeled the “snowball effect.” Finally, the model, whose major use would be in overall strategic planning, is illustrated with an example.  相似文献   
95.
In this paper the application of results of dynamical system theory to urban retail models will be discussed. First of all attention is paid to the equilibria of these models; their existence and uniqueness as well as their stability. Next the results are aggravated to the situation of a two zonal system. Finally some economic consequences of parameter changes are described.  相似文献   
96.
This article investigates transitions at the level of societal functions (e.g., transport, communication, housing). Societal functions are fulfilled by sociotechnical systems, which consist of a cluster of aligned elements, e.g., artifacts, knowledge, markets, regulation, cultural meaning, infrastructure, maintenance networks and supply networks. Transitions are conceptualised as system innovations, i.e., a change from one sociotechnical system to another. The article describes a co-evolutionary multi-level perspective to understand how system innovations come about through the interplay between technology and society. The article makes a new step as it further refines the multi-level perspective by distinguishing characteristic patterns: (a) two transition routes, (b) fit–stretch pattern, and (c) patterns in breakthrough.  相似文献   
97.
This paper combines an engineering process model of the cost of local exchange telecommunications firms with an analytical model of optimal incentive regulation (with ex post cost observability), to study empirically the properties of the optimal regulatory mechanism. Relying on detailed properties of the cost function, we examine three issues: (i) the extent of natural monopoly when informational rents associated with regulation are taken into account; (ii) the extent of incentive correction, which expresses the divergence of pricing under the optimal mechanism from optimal pricing under complete information; (iii) the implementation of optimal regulation through a menu of linear contracts. Our findings are that, for fixed territory, strong economies of scale allow local exchange telecommunications to retain monopoly characteristics even when the (informational) costs of regulation are properly accounted for, the incentive correction term is small in magnitude, and that optimal regulation can be well approximated through relatively simple linear contracts.  相似文献   
98.
In the last few years bipartisan support for legalizing drugs has grown to a surprising level. Because of the lack of involvement of the business community in this debate, we surveyed the human resource managers of 127 firms about their perceptions of the effects of legalization. Their responses were uniformly negative, with expectations that drug use, absenteeism, worksite crime, and liability costs would increase, while the quality and quantity of work would decline. They also forecast increases in drug testing, performance monitoring, and education and rehabilitation programs as a result.  相似文献   
99.
The study examines the origins of technology important to improving productivity in the food-processing industries. Technology flows were measured both by patents in patent classes closely identified with six food industries, and by a sample of significant food-processing innovations. These data are consistent with the hypothesis that interindustry technology flows are the most significant determinant of productivity improvements in the food industries. These findings solve the enigma that the food-processing industries have enjoyed rapid improvements in productivity despite making very modest investments in research and development.  相似文献   
100.
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