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   21937篇
  免费   535篇
  国内免费   41篇
管理学   2751篇
民族学   137篇
人口学   1791篇
丛书文集   373篇
教育普及   1篇
理论方法论   1867篇
综合类   1598篇
社会学   10095篇
统计学   3900篇
  2023年   163篇
  2022年   136篇
  2021年   201篇
  2020年   396篇
  2019年   548篇
  2018年   657篇
  2017年   845篇
  2016年   661篇
  2015年   489篇
  2014年   684篇
  2013年   3675篇
  2012年   876篇
  2011年   876篇
  2010年   698篇
  2009年   617篇
  2008年   714篇
  2007年   626篇
  2006年   672篇
  2005年   520篇
  2004年   496篇
  2003年   405篇
  2002年   417篇
  2001年   502篇
  2000年   429篇
  1999年   411篇
  1998年   315篇
  1997年   265篇
  1996年   283篇
  1995年   292篇
  1994年   250篇
  1993年   258篇
  1992年   302篇
  1991年   294篇
  1990年   289篇
  1989年   253篇
  1988年   239篇
  1987年   202篇
  1986年   229篇
  1985年   249篇
  1984年   216篇
  1983年   191篇
  1982年   159篇
  1981年   130篇
  1980年   155篇
  1979年   170篇
  1978年   133篇
  1977年   114篇
  1976年   87篇
  1975年   91篇
  1974年   93篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
981.
Abstract Data from the 1990 U. S. Census are used to examine nonmetro-metro distinctions in the outmarriage patterns of the nation's two largest minority groups—African Americans and Mexican Americans. The analysis is guided by a multilevel model combining individual- and community-level determinants of outmarriage. Consistent with notions suggesting that persons in metro areas are less traditional and, perhaps, more tolerant of those different from them, we find that African Americans living in metro areas are more likely to be married to someone from another racial/ethnic group than their peers in nonmetro areas, even after residential differences in individual and community characteristics are taken into account. On the other hand, controlling for other factors, Mexican Americans living in metro areas are not any more likely than those living in nonmetro settings to be exogamous. One possible explanation for this divergent pattern is the relatively recent urbanization of the Mexican American population.  相似文献   
982.
983.
Children of Adolescent Mothers: Cognitive and Behavioral Status at Age Six   总被引:1,自引:0,他引:1  
The cognitive and behavioral status at age six years of 185 children of adolescent mothers (60.5% boys) were assessed using the mother (CBCL) and teacher (TRF) report forms of the Child Behavior Checklist and the Bracken Basic Concepts Scale. There was evidence for impairment in all areas of functioning. More than half of the sample exceeded the borderline clinical cutoff (T = 60) on either the CBCL or TRF Total Problem score, and nearly half the sample had Bracken scores that were more than 1 SD below the normative mean. Only 26.9% of the children were in the normal range on all three measures. These results are discussed in terms of implications for social work practice with children and adolescent mother families.  相似文献   
984.
Testosterone, Smiling, and Facial Appearance   总被引:1,自引:0,他引:1  
In a study of possible links between testosterone and dominance, 119 men and 114 women provided saliva samples for testosterone assay and posed smiling and not smiling for portrait photographs. Expert judges viewing the photographs found smaller smiles among high than low testosterone men, with less zygomatic major (raising the corners of the mouth) and orbicularis oculi (raising the cheeks and crinkling around the corners of the eyes) muscle activity. Naive judges viewing individual photographs gave higher potency ratings to smiling high testosterone men than smiling low testosterone men. Naive judges viewing photographs grouped into high and low testosterone sets gave higher potency and lower goodness ratings to high than to low testosterone men, regardless of whether they were smiling. Among women, judges found only slight relationships between testosterone and facial appearance. The pattern among men of less smiling with higher testosterone levels fits with research linking testosterone to face-to-face dominance.  相似文献   
985.
The Collaborative Demonstration Program for Homeless Individuals is providing an opportunity for several community agencies in the United States to explore innovative intervention and treatment strategies to address the needs of homeless people with co-occurring (mental illness and substance abuse) disorders. This cooperative agreement, funded jointly by the Center for Mental Health Services (CMHS) and the Center for Substance Abuse Treatment (CSAT), is a $3 million project supporting programs in various community agencies to develop, document, and evaluate programs for persons who are homeless with co-occurring disorders to be used as models in other communities. The program models include: Assertive Community Treatment, Psychosocial Rehabilitation, Therapeutic Community, and an integrated treatment model. The first phase of the two-phase project funded 16 programs in the U.S. to develop manuals within their primary treatment modalities for homeless people with co-occurring disorders. For Phase II of the project, six of the 16 model programs were competitively selected to demonstrate program impact through formal program evaluation efforts. The data derived from the various projects will be compiled into a compendium of information for state agencies and community service providers throughout the U.S.  相似文献   
986.
SUMMARY An optimization problem which provides a new characterization for ridge regression is discussed. A variant of this optimization problem leads to a new family of biased estimators that includes the Stein estimation method and principal components regression as particular cases. The whole approach is illustrated on the basis of real data sets.  相似文献   
987.
Abstract. By means of a series of examples, from classic contributions to probability theory as well as the author's own, an attempt is made to convince the reader that problem solving is often a matter of cooking up an appropriate Markov chain. Topics touched upon along the way include coupling, correlation inequalities, and percolation.  相似文献   
988.
Abstract.  The Nelson–Aalen estimator is well known to be an asymptotically efficient estimator of the cumulative hazard function, see Andersen et al. ( Statistical models based on counting processes , Springer-Verlag, New York, 1993) among many others. In this paper, we show that the efficiency of the Nelson–Aalen estimator can be considerably improved by using more information in the estimation process than the traditional Nelson–Aalen estimator uses. While our approach results in a biased estimator, the variance improvement is substantial. By optimizing the balance between the bias loss and the variance improvement, we obtain results on the efficiency gain. Several examples for known failure time distributions are used to illustrate these ideas.  相似文献   
989.
Absenteeism, turnover and disability, and relationships between them have been studied among city bus drivers in the Netherlands. The theoretical framework for the study was a cumulative process model of work and health. Absenteeism among these drivers was two to three times as high as the national average, while the risk of disablement was more than twice as high as the risk for male Dutch civil servants in general. Bus drivers who had to leave their job for medical reasons did so at a younger age than other groups of civil servants. The main conditions leading to disablement related to the back, tendons and joints (35%), mental disorders (35%) and cardiovascular diseases (12%). It was shown that long-term absenteeism is a strong precursor of future disability. The research suggests a work-related process of progressive deterioration of health and well-being over a reasonably long period of time. Driving city buses seems to be an occupation with high risks for health and well-being.  相似文献   
990.
This study attempts to identify stimuli that produce changes in death penalty opinions and to determine whether public commitment to a death penalty opinion has an effect on that opinion. Consistent with previously reported findings, the results of this study suggest that public commitment has a substantial inhibitory effect on opinion change. Reasons for both changing and maintaining death penalty opinions are provided, and the implications of the research are discussed.  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