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   12684篇
  免费   361篇
  国内免费   1篇
管理学   1490篇
民族学   65篇
人口学   1088篇
丛书文集   76篇
教育普及   3篇
理论方法论   1174篇
综合类   151篇
社会学   6951篇
统计学   2048篇
  2023年   77篇
  2021年   82篇
  2020年   181篇
  2019年   277篇
  2018年   322篇
  2017年   437篇
  2016年   317篇
  2015年   231篇
  2014年   305篇
  2013年   2552篇
  2012年   368篇
  2011年   363篇
  2010年   265篇
  2009年   248篇
  2008年   273篇
  2007年   267篇
  2006年   285篇
  2005年   264篇
  2004年   222篇
  2003年   190篇
  2002年   219篇
  2001年   288篇
  2000年   271篇
  1999年   283篇
  1998年   179篇
  1997年   163篇
  1996年   221篇
  1995年   214篇
  1994年   221篇
  1993年   229篇
  1992年   235篇
  1991年   220篇
  1990年   245篇
  1989年   214篇
  1988年   200篇
  1987年   180篇
  1986年   166篇
  1985年   173篇
  1984年   178篇
  1983年   126篇
  1982年   123篇
  1981年   104篇
  1980年   118篇
  1979年   114篇
  1978年   96篇
  1977年   87篇
  1976年   84篇
  1975年   85篇
  1974年   57篇
  1973年   54篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
61.
The development of the gambling market in the Federal Republic of Germany since the middle of the seventies and data on pathological gamblers seeking help are described. The continuously increasing supply, together with increases in turnover, was followed-with some temporal delay-by an increase in the number of gamblers who sought advice and treatment. Preliminary measures taken by the health authorities as well as some consequences of pathological gambling are discussed.This article is a translation of a German article published in: Deutsche Hauptstelle gegen die Suchtgefahren (1990): Jahrbuch '91 zur Frage der Suchtgefahren. Hamburg: Neuland-Verlag.  相似文献   
62.
63.
Resocialization is pulled out of its structuralist roots and recast into an interactionist framework. Building on a substantive theory of the resocialization experience of becoming an adoptive parent, three theoretical properties of interactionist resocialization are presented. These can be summarized as involving unlearning and relearning some aspects of a core identity; the interpretation and active reconstruction of that identity which has reciprocal effects on all actors involved; and finally, the effects of both situational and trans-situational norms that give shape to the resocialization experience. Suggestions are made for other substantive areas of research that could be used for comparative analysis in order to further refine a formal theory of interactionist resocialization.  相似文献   
64.
Career and personal counseling are inextricably intertwined. Career problems have a strong emotional component. Career indecision and procrastination may be better interpreted as zeteophobia, the fear of career exploration. Trait and factor theory pictures career counseling as unrealistically simplistic and leads neophytes to view it as boring. Training all counselors to integrate career and personal counseling would lead to better service for clients.  相似文献   
65.
66.
In the development of many diseases there are often associated random variables which continuously reflect the progress of a subject towards the final expression of the disease (failure). At any given time these processes, which we call stochastic covariates, may provide information about the current hazard and the remaining time to failure. Likewise, in situations when the specific times of key prior events are not known, such as the time of onset of an occult tumour or the time of infection with HIV-1, it may be possible to identify a stochastic covariate which reveals, indirectly, when the event of interest occurred. The analysis of carcinogenicity trials which involve occult tumours is usually based on the time of death or sacrifice and an indicator of tumour presence for each animal in the experiment. However, the size of an occult tumour observed at the endpoint represents data concerning tumour development which may convey additional information concerning both the tumour incidence rate and the rate of death to which tumour-bearing animals are subject. We develop a stochastic model for tumour growth and suggest different ways in which the effect of this growth on the hazard of failure might be modelled. Using a combined model for tumour growth and additive competing risks of death, we show that if this tumour size information is used, assumptions concerning tumour lethality, the context of observation or multiple sacrifice times are no longer necessary in order to estimate the tumour incidence rate. Parametric estimation based on the method of maximum likelihood is outlined and is applied to simulated data from the combined model. The results of this limited study confirm that use of the stochastic covariate tumour size results in more precise estimation of the incidence rate for occult tumours.  相似文献   
67.
In a recent paper in this journal, Lee, Kapadia and Brock (1980) developed maximum likelihood (ML) methods for estimating the scale parameter of the Rayleigh distribution from doubly censored samples. They reported convergence difficulties in attempting to solve numerically the nonlinear likelihood equation (LE). To mitigate these difficulties, they employed approximations to simplify the LE, but found that the solution of the resulting simplified equation can give rise to parameter estimates of erratic accuracy. We show that the use of approximations to simplify the LE is unnecessary. In fact, under suitable parametric transformation, the log-likelihood function is strictly concave, the ML estimate always exists, is unique and finite. Furthermore, the LE is easy to solve numerically. A numerical example is given to illustrate the computations involved.  相似文献   
68.
Dental caries in children is now recognized as a preventable disease. The use of fluoride and sealants has produced a major reduction in caries prevalence among school aged children in the United States and other countries. A portion of the child population who are educationally and socioeconomically disadvantaged are not fully receiving these benefits. Public policy, insurance and medicaid groups must be made aware of these preventative measures and strategies developed to implement them.  相似文献   
69.
70.
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