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   89500篇
  免费   2944篇
  国内免费   5篇
管理学   12356篇
民族学   546篇
人才学   26篇
人口学   6813篇
丛书文集   529篇
理论方法论   9366篇
综合类   2197篇
社会学   41869篇
统计学   18747篇
  2023年   501篇
  2021年   566篇
  2020年   1505篇
  2019年   2212篇
  2018年   2065篇
  2017年   3123篇
  2016年   2369篇
  2015年   2039篇
  2014年   2622篇
  2013年   18823篇
  2012年   2347篇
  2011年   2147篇
  2010年   1970篇
  2009年   2193篇
  2008年   2024篇
  2007年   1854篇
  2006年   2091篇
  2005年   2280篇
  2004年   2149篇
  2003年   1875篇
  2002年   1975篇
  2001年   1969篇
  2000年   1752篇
  1999年   1657篇
  1998年   1486篇
  1997年   1329篇
  1996年   1310篇
  1995年   1316篇
  1994年   1281篇
  1993年   1276篇
  1992年   1256篇
  1991年   1190篇
  1990年   1161篇
  1989年   1006篇
  1988年   1111篇
  1987年   979篇
  1986年   865篇
  1985年   1052篇
  1984年   1105篇
  1983年   995篇
  1982年   925篇
  1981年   836篇
  1980年   800篇
  1979年   862篇
  1978年   762篇
  1977年   685篇
  1976年   648篇
  1975年   629篇
  1974年   509篇
  1973年   436篇
排序方式: 共有10000条查询结果,搜索用时 468 毫秒
701.
The development and initial psychometric properties of an adolescent gambling problem severity measure are described. The scale, based on a revision of the South Oaks Gambling Screen (Lesieur & Blume, 1987), was administered to 1,101 older (ages 15 to 18) Minnesota adolescents as part of a state-wide gambling survey. Study results indicated that the scale had moderate internal consistency reliability and was significantly related to alternate measures of problem severity for male subjects. Because the rate and severity of gambling among females was very low, the psychometric adequacy of the scale for females is not known at this time. The implications of study findings to the conceptual understanding of adolescent gambling problem severity as well as study limitations and future research needs, are discussed.Support for the study was provided by the Minnesota Department of Human Services and the Center for Addiction Studies, University of Minnesota, Duluth. The authors gratefully acknowledge the assistance from Robert Blum, Linda Harris, Durand Jacobs, J. Laundergan, Alan Mathiason, Brenda Miller, James Schaefer, school officials from the participating high schools, and interviewers who assisted with the telephone survey.  相似文献   
702.
The issue of work place hazards that may threaten the health of an unborn child has long been problematic for women, business decision-makers, and lawmakers. The desire to protect the developing foetus must be balanced against a woman's legal right to get and keep the job of her choice. The issue has never been easy to resolve, as this historical analysis shows. An overview of the potential effects of work place hazards on reproductive health is presented. Relevant fair employment laws are summarized, and a brief history of court cases and employer practices is provided. It is argued that ultimately, foetal protection policies had little or nothing to do with protection of foetuses. They may have had more to do with protecting the employer from potential liability and with perceptions of women's status in the work place than with protecting the next generation. Finally, suggestions for future research are presented.  相似文献   
703.
对普通高校体育教学改革的几点认识   总被引:1,自引:0,他引:1  
根据目前高校体育教学的现状 ,提出高校体育教育要以培养学生学习体育的兴趣为原则 ,调整教学内容、改善教学方法 ,要使学生养成终身锻炼的习惯。  相似文献   
704.
县域经济作为宏观与微观结合的中观层面 ,随着市场经济的发展已越来越引起大家的重视。本文通过对重庆铜梁县域经济调查 ,认为它在适应市场的改革、文化和城市建设、政府职能的转变等方面有许多可取的经验值得推广 ,也存在一些内地县市所共有的问题需要解决。本文试图介绍铜梁县域经济发展的主要成就 ,归纳内地县域经济普遍存在的一些问题 ,并提出一些具体的解决思路  相似文献   
705.
A powerful practical solution is by far the most desired output when making decisions under the realm of uncertainty on any safety-critical marine or offshore units and their systems. With data and information typically being obtained incrementally, adopting Bayesian network (BN) is shown to realistically deal with the random uncertainties while at the same time making risk assessments easier to build and to check. A well-matched methodology is proposed to formalize the reasoning in which the focal mechanism of inference processing relies on the sound Bayes's rule/theorem that permits the logic. Expanding one or more influencing nodal parameters with decision and utility node(s) also yields an influence diagram (ID). BN and ID feasibility is shown in a marine evacuation scenario and that of authorized vessels to floating, production, storage, and offloading collision, developed via a commercial computer tool. Sensitivity analysis and validation of the produced results are also presented.  相似文献   
706.
The small sample performance of least median of squares, reweighted least squares, least squares, least absolute deviations, and three partially adaptive estimators are compared using Monte Carlo simulations. Two data problems are addressed in the paper: (1) data generated from non-normal error distributions and (2) contaminated data. Breakdown plots are used to investigate the sensitivity of partially adaptive estimators to data contamination relative to RLS. One partially adaptive estimator performs especially well when the errors are skewed, while another partially adaptive estimator and RLS perform particularly well when the errors are extremely leptokur-totic. In comparison with RLS, partially adaptive estimators are only moderately effective in resisting data contamination; however, they outperform least squares and least absolute deviation estimators.  相似文献   
707.
Daughters from low‐income families who did not receive Aid to Families with Dependent Children (AFDC) are compared to daughters from low‐income families who did receive assistance to better account for family income in the intergenerational association of AFDC. The research models the timing of a daughter's first birth and, for those who become mothers, the number of years a daughter receives any AFDC. Women whose families received AFDC during their childhood are more likely to receive AFDC as adults relative to those women whose families did not receive AFDC. Controlling for family income in a more careful and comprehensive way than past research explains part but not all of the effects of childhood AFDC receipt. Among daughters from chronically poor families, however, parental AFDC use is not associated with additional years of AFDC participation. Although the present research cannot confirm or deny a causal role for parental welfare use, the intergenerational transmission of financial resources does explain part of the intergenerational association of welfare use.  相似文献   
708.
该文依据分类学的原则 ,剖析了沿用一千多年的“永字八法” ,减撇加折 ,构成了“新永字八法”。同时推出了“方圆米格” ,不仅适用于楷书 ,也可传习行、草、隶、篆诸种书体。改进后的“大小多用方圆米格” ,既可写大小多种字体 ,又能提高利用率。  相似文献   
709.
Many methods for obtaining graphical representations of multivariate data have been suggested over the last decade, but it is only relatively recently that software has become available which makes use of these procedures routine. In this paper, a number of examples are used to illustrate the application of graphical methods for the exploration of multivariate data. The diagrams produced may prove useful in consultations with clients and in examining the results from more formal methods.  相似文献   
710.
A log-linear modelling approach is proposed for dealing with polytomous, unordered exposure variables in case-control epidemiological studies with matched pairs. Hypotheses concerning epidemiological parameters are shown to be expressable in terms of log-linear models for the expected frequencies of the case-by-control square concordance table representation of the matched data; relevant maximum likelihood estimates and goodness-of-fit statistics are presented. Possible extensions to account for ordered categorical risk factors and multiple controls are illustrated, and comparisons with previous work are discussed. Finally, the possibility of implementing the proposed method with GLIM is illustrated within the context of a data set already analyzed by other authors.  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