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   7820篇
  免费   173篇
财政金融   1462篇
工业经济   677篇
计划管理   1320篇
经济学   1701篇
综合类   85篇
运输经济   46篇
旅游经济   122篇
贸易经济   1311篇
农业经济   392篇
经济概况   872篇
信息产业经济   1篇
邮电经济   4篇
  2021年   58篇
  2020年   95篇
  2019年   137篇
  2018年   162篇
  2017年   171篇
  2016年   184篇
  2015年   99篇
  2014年   183篇
  2013年   769篇
  2012年   240篇
  2011年   273篇
  2010年   225篇
  2009年   258篇
  2008年   218篇
  2007年   222篇
  2006年   187篇
  2005年   193篇
  2004年   170篇
  2003年   165篇
  2002年   148篇
  2001年   180篇
  2000年   182篇
  1999年   160篇
  1998年   144篇
  1997年   131篇
  1996年   130篇
  1995年   131篇
  1994年   114篇
  1993年   128篇
  1992年   131篇
  1991年   113篇
  1990年   120篇
  1989年   113篇
  1988年   119篇
  1987年   98篇
  1986年   115篇
  1985年   131篇
  1984年   129篇
  1983年   112篇
  1982年   117篇
  1981年   112篇
  1980年   114篇
  1979年   92篇
  1978年   107篇
  1977年   84篇
  1976年   80篇
  1975年   64篇
  1974年   60篇
  1973年   54篇
  1972年   54篇
排序方式: 共有7993条查询结果,搜索用时 0 毫秒
31.
Unemployment has been identified as one of the main problems confronting South Africa. Recently, in order to improve rural infrastructure and create employment, several pilot projects of rural road construction have been initiated in South Africa. In such a context it is considered that attention should be drawn to a pilot project carried out some time ago in Botswana to examine the potential of labour‐intensive methods in the construction and maintenance of rural roads.

The main conclusion of the pilot project was that labour‐intensive methods were viable, although attention had to be paid to several critical factors. In 1982, following its evaluation of the pilot project, the Government of Botswana decided that over the next five years the technical and organisational methods developed during the pilot project should be replicated throughout Botswana.

After a brief survey of the background to the project, the paper summarises several important features of the pilot project and its main findings. The paper closes with some comments on the implications of this pilot project for those currently underway in South Africa.  相似文献   

32.
Pacific Presbyterian Medical Center has chalked up an impressive string of successes. What's ahead? A $20 million cancer center.  相似文献   
33.
34.
35.
The paper analyzes the employment policy of a firm that can vary both hours and the level of employment. The analysis differs from previous work in the adjustment cost literature in that the firm is able to change its employment not only through hires, layoffs, and quits, but also by recalls of employees who were previously laid off. Thus, we introduce the possibility of the firm inventorying the labor input. It is shown that this labor inventory potential is necessary if the firm is to ever lay off workers. Further, it is demonstrated that linear rather than strictly convex adjustment costs are then required if the firm is to always recall employees who were previously laid off prior to hiring new workers.  相似文献   
36.
Collaborating researchers used a multi equation model to analyze 3080 mother-infant pairs living on the island of Cebu in the central Philippines and to estimate a child health production function. The econometric methods used eliminated obstacles such as heterogeneity and endogeneity of significant explanatory factors. They also maximized the longitudinal quality of the data. The results showed that morbidity in 1 period reduced infant weight in following periods. For example, diarrhea and febrile respiratory infection reduced growth in the time period following the illnesses. Further effects of some contributing factors were great near birth not diminished with age. For example, breast feeding promoted growth and protected against infection, especially diarrhea and febrile respiratory infection, more substantially near birth than it did later. Further, in urban areas, preventive health care positively affected growth independently of its indirect influence on reducing respiratory infection. Yet it had little effect on diarrhea. Diarrhea had a strong adverse effect on growth. Exposure of the infant to enteric pathogens had the greatest influence on production of diarrhea. In urban areas, exposure included water supply contamination, exposure to feces, a more pathogenic diet, and community crowding. In rural areas, however, exposure included community crowding and increased rainfall which presumably washed feces into the water supply. Household crowding in both urban and rural areas and irritation from smoke in urban areas only tended to bring about febrile respiratory infection.  相似文献   
37.
Abstract  The tables for the Friedman rank-test arc extended using a sampling method. A table is given for the traditional significance levels .01, .025, .05 and .10 for number of blocks equal to 7 and 8 and for treatments of size 6 and 7. A brief discussion of available tables is also included along with an example of an application.  相似文献   
38.
Abstract . An empirical analysis of the property crimes, robbery, burglary and larceny, is presented for all 120 counties in Kentucky. While this analysis is based on an economic model of crime, certain sociological and legal variables are included as well in the system of equations. Overall, the empirical results support prior studies’findings with the exception that a quadratic relationship is found to exist between urbanization and each of the property crimes. Furthermore, neither the economic nor the non economic influences measured appear more important for affecting crime rates. Specifically, results indicate that the level of poverty, the degree of tourism, the presence of police, the unemployment rate and the apprehension rate all affect property crimes. In contrast, the length of sentence, the degree of industrialization, the level of public assistance payments and the proportion of youth in the county have no affect on property crime rates in these areas.  相似文献   
39.
The case is investigated when Hoeffding's one sample U–statistic theorem for the sample variance S2 is not applicable. It is shown that this occurs only when the parent distribution is the two–point distribution with jumps of equal magnitude. For this exceptional case the standardised S2 is shown to converge in distribution to (1 – V )√2, where V has chi–square distribution with one degree of freedom.  相似文献   
40.
In our earlier paper [Srivastava, Agnihotri and Dwivedi (1980)] the dominance of double k-class over k-class with respect to exact mean squared error matrix criteria is established. It is observed that given a member of k-class, one can pick up a member of double k-class that will provide an improved estimator of the coefficients. This result prompted us to study the exact finite sample properties of the double k-class estimator. For this, we have considered a structural equation containing two endogenous variables and have investigated the properties of double k-class estimators of the coefficients of explanatory endogenous variables assuming characterizing scalars to be non-stochastic.  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