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   12680篇
  免费   296篇
财政金融   2284篇
工业经济   1003篇
计划管理   2175篇
经济学   3000篇
综合类   152篇
运输经济   80篇
旅游经济   150篇
贸易经济   1847篇
农业经济   597篇
经济概况   1628篇
邮电经济   60篇
  2021年   78篇
  2020年   149篇
  2019年   223篇
  2018年   251篇
  2017年   307篇
  2016年   275篇
  2015年   180篇
  2014年   308篇
  2013年   1271篇
  2012年   349篇
  2011年   394篇
  2010年   327篇
  2009年   423篇
  2008年   351篇
  2007年   302篇
  2006年   304篇
  2005年   287篇
  2004年   240篇
  2003年   301篇
  2002年   267篇
  2001年   253篇
  2000年   261篇
  1999年   259篇
  1998年   231篇
  1997年   241篇
  1996年   207篇
  1995年   180篇
  1994年   180篇
  1993年   209篇
  1992年   215篇
  1991年   201篇
  1990年   207篇
  1989年   176篇
  1988年   177篇
  1987年   166篇
  1986年   185篇
  1985年   223篇
  1984年   201篇
  1983年   191篇
  1982年   171篇
  1981年   189篇
  1980年   170篇
  1979年   193篇
  1978年   156篇
  1977年   143篇
  1976年   129篇
  1975年   96篇
  1974年   101篇
  1973年   105篇
  1972年   80篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
52.
53.
54.
On the concept of optimum population   总被引:4,自引:0,他引:4  
The economic welfare of a community is affected by policies that determine both the rate of capital accumulation and the rate of growth of population. The optimum size of population at any point is time will depend on the size of the existing capital stock and the optimum rate of savings will depend on the existing number of people. Consequently, in this sense, a population policy cannot be developed without a concurrent savings policy. The criterion of optimality that will be used is the ma ximization of the total discounted welfare of all generations from now to infinity. The problem will be to select that rate of savings and that size of population at every moment which will achieve this maximum welfare if, in fact, a maximum exists. An inquiry is made into the existence of an optimum policy under various circumstances. An attempt is made to evaluate the consequences of various ethical beliefs.  相似文献   
55.
The attempt was made to obtain an improved estimate of the economic value of birth control programs in developing countries. A medium sized econometric simulation model -- based on data covering a cross-section of 67 countries -- was constructed to investigate the implications to a developing economy of birth prevention. Fertility measures were included in the model as important endogenous variables in the economic process, and parameter values were supplied by formal estimation rather than expert judgment. A matrix of age-specific birth and survival rates was used. The model has sufficient detail to generate a complete age distribution for the population, yielding improved estimates of the value of birth control and other growth policies. Initial focus is on the construction of the model. This is followed by simulation of the system with simulated paths compared to observed paths for a few countries. Projections of real per capita output and other variables with and without the presence of a birth control program are presented. The size of the differential economic effect associated with lower fertility is examined for 17 sets of initial conditions corresponding to a selection of 17 developing countries. Comparisons of birth control with other forms of investment are made.  相似文献   
56.
57.
Seven computerprograms for non-linear regression or curve fitting problems are compared. The comparison of the programs, running in different computing centra, is restricted to the fit performance. Six model functions are fitted according to the least squares criterion to data series, arising from practical work. The special least squares minimization programs turned out to be better suited for these problems than general optimizing programs.  相似文献   
58.
Questo lavoro pone la monotonia generalizzata come un opportuno strumento per uno sviluppo controllato di funzioni scalari e vettoriali. E' cosi possibile caratterizzare la relazione tra su spazi vettoriali.
Summary Some generalized monotonicity properties are analyzed both for scalar and vector functions. In particular the relation between and the class of functions, which are able to preserve it, are studied.
  相似文献   
59.
Simulated annealing: An introduction   总被引:1,自引:0,他引:1  
  相似文献   
60.
Here the author reviews the stated positions and responses of unions towards employer initiated human resource management developments. The information reviewed is drawn from Canada, Britain and the USA, with some differences being apparent between countries.  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