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   13834篇
  免费   335篇
管理学   1815篇
民族学   59篇
人才学   1篇
人口学   1198篇
丛书文集   86篇
教育普及   2篇
理论方法论   1287篇
综合类   342篇
社会学   7032篇
统计学   2347篇
  2021年   69篇
  2020年   213篇
  2019年   254篇
  2018年   276篇
  2017年   408篇
  2016年   312篇
  2015年   248篇
  2014年   281篇
  2013年   2238篇
  2012年   440篇
  2011年   364篇
  2010年   248篇
  2009年   264篇
  2008年   308篇
  2007年   313篇
  2006年   253篇
  2005年   388篇
  2004年   330篇
  2003年   291篇
  2002年   303篇
  2001年   341篇
  2000年   319篇
  1999年   334篇
  1998年   229篇
  1997年   221篇
  1996年   232篇
  1995年   206篇
  1994年   219篇
  1993年   191篇
  1992年   253篇
  1991年   258篇
  1990年   222篇
  1989年   228篇
  1988年   206篇
  1987年   193篇
  1986年   197篇
  1985年   188篇
  1984年   219篇
  1983年   209篇
  1982年   176篇
  1981年   147篇
  1980年   144篇
  1979年   175篇
  1978年   143篇
  1977年   125篇
  1976年   113篇
  1975年   111篇
  1974年   101篇
  1973年   101篇
  1971年   66篇
排序方式: 共有10000条查询结果,搜索用时 437 毫秒
991.
It is shown that the product of two independent random variables in the domain of attraction of the normal distribution is also in the domain of attraction of the normal distribution, while if the product is in the domain of attraction of the normal distribution and one of the variables has finite variance, the other is in the domain of attraction of the normal distribution. This result is applied to prove the asymptotic normality of the regression coefficient in a linear regression when the error variance is not necessarily finite.  相似文献   
992.
993.
Time series analysis of fertility can improve demographic forecasts. The optimal forecast and its variance for births to an age-structured population subject to serially correlated random fertility are developed. The general case in which the fertility process had arbitrary autoregressive structure is dealt with and then the 4 special cases of white noise, 1st-order autoregressive, 2nd-order autoregressive, and random walk are considered. Consequently, it is determined that the predictions and their variances are highly sensitive to the autoregressive structure of fertility and, therefore, if stochastic models are to be used for prediction, they must emphasize this aspect of the problem. Preliminary empirical efforts to model the time series of U.S. fertility from 1917 to 1972 proved unsuccessful, but it is obvious that at least a 2nd-order autoregressive scheme is require d. The analysis proveded should be helpful in: 1) any application of the procedures requires a successful parameterization of the fertility process; 2) fertility variations could be decomposed into the effects of nuptiality and marital fertility and then births and marriages could be jointly predicted; and 3) the simplifying approximations should be dropped and each age-specific rate could be analyzed and predicted.  相似文献   
994.
995.
996.
The probability of first marriage for men who graduated from Wisconsin high schools in 1957 was analyzed with respect to their Social Security earnings records, Wisconsin income tax reports for parents, and other variables. The findings provide no support for Easterlin's hypothesis that marriage will occur earlier when young men judge their economic prospects favorably with respect to their parents' income. However, young men's earnings and time spent in schooling to increase them were found to be important influences on marriage timing. Additional schooling had little effect net of the time it absorbed.  相似文献   
997.
Health professionals' attitudes toward abortion   总被引:1,自引:0,他引:1  
Attitudes toward abortion, as obtained in a 1971 nationwidesurvey, are presented for students and faculty in nursing, medicine,and social work, and are compared to attitudes of the generalpopulation. Attitudinal differences are examined among the professions,between students and faculty, and in terms of religion. Theresults reveal implications for the abortion-related servicesprovided by health professionals.  相似文献   
998.
The so-called “principal formulae” of planar integral geometry are conventionally couched in terms of the “kinematic density”dxdydθ. Here a corresponding theory with respect to the “Lebesgue density”dxdy, that is with rotations suppressed, is developed. The only real difference is that the new “fundamental formula of Blaschke”contains a term depending upon the relative orientations of the two domains involved. In particular, the remarkable iteration property of these formulae carries over. The usual principal formulae follow as a corollary of the formulae given here, upon, averaging over orientations.  相似文献   
999.
1000.
An attempt is made to establish primary integration as a major variable in explaining citizen involvement in political life. It is argued that a convincing case requires a demonstration that the variable is both empirically important and theoretically meaningful. The former is examined through data from a sample survey of an English city. Theoretical meaning is established through focussing upon the idea of sociable talk as a key factor in reality construction, including the construction of political events as a proximate world available for the interest and participation by the individual.  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