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   8918篇
  免费   152篇
财政金融   1877篇
工业经济   663篇
计划管理   1407篇
经济学   1871篇
综合类   116篇
运输经济   55篇
旅游经济   178篇
贸易经济   1409篇
农业经济   320篇
经济概况   1168篇
邮电经济   6篇
  2020年   85篇
  2019年   130篇
  2018年   160篇
  2017年   179篇
  2016年   158篇
  2015年   111篇
  2014年   164篇
  2013年   1009篇
  2012年   234篇
  2011年   262篇
  2010年   227篇
  2009年   254篇
  2008年   238篇
  2007年   183篇
  2006年   195篇
  2005年   172篇
  2004年   183篇
  2003年   176篇
  2002年   182篇
  2001年   170篇
  2000年   164篇
  1999年   157篇
  1998年   170篇
  1997年   161篇
  1996年   152篇
  1995年   123篇
  1994年   126篇
  1993年   140篇
  1992年   159篇
  1991年   161篇
  1990年   115篇
  1989年   114篇
  1988年   96篇
  1987年   111篇
  1986年   120篇
  1985年   157篇
  1984年   135篇
  1983年   165篇
  1982年   135篇
  1981年   124篇
  1980年   140篇
  1979年   125篇
  1978年   94篇
  1977年   108篇
  1976年   102篇
  1975年   100篇
  1974年   91篇
  1973年   73篇
  1972年   62篇
  1971年   61篇
排序方式: 共有9070条查询结果,搜索用时 0 毫秒
101.
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   
102.
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   
103.
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   
104.
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   
105.
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   
106.
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   
107.
108.
In an age when the role, behaviour and performance of the firm are under greater scrutiny than ever before, it is important to pursue quantitative empirical research in the area of social auditing. Using data relating to one particular company, the various inputs and outputs attributable to the firm's different stakeholders, (shareholders, employees, consumers and the community) are examined and corresponding rates of return calculated. Considerable methodological and data problems arise and consequently the results need careful interpretation.  相似文献   
109.
110.
Counternarcotics interdiction efforts have traditionally relied on historically determined sorting criteria or “best guess” to find and classify suspected smuggling traffic. We present a more quantitative approach which incorporates customized database applications, graphics software and statistical modeling techniques to develop forecasting and classification models. Preliminary results show that statistical methodology can improve interdiction rates and reduce forecast error. The idea of predictive modeling is thus gaining support in the counterdrug community. The problem is divided into sea, air and land forecasting, only part of which will be addressed here. The maritime problem is solved using multiple regression in lieu of multivariate time series. This model predicts illegal boat counts by behavior and geographic region. We developed support software to present the forecasts and to automate the process of performing periodic model updates. During the period, the model was in use at. Coast Guard Headquarters. Because of deterrence provided by improved intervention, the vessel seizure rate declined from 1 every 36 hours to 1 every 6 months. Due in part to the success of the sea model, the maritime movement of marijuana has ceased to be a major threat. The air problem is more complex, and required us to locally design data collection and display software. Intelligence analysts are using a customized relational database application with a map overlay to perform visual pattern recognition of smuggling routes. We are solving the modeling portion of the air problem using multiple regression for regional forecasts of traffic density, and discriminant analysis to develop tactical models that classify “good guys” and “bad guys”. The air models are still under development, but we discuss some modeling considerations and preliminary results. The land problem is even more difficult, and data collection is still in progress.  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