全文获取类型
收费全文 | 11982篇 |
免费 | 189篇 |
国内免费 | 1篇 |
专业分类
管理学 | 1474篇 |
民族学 | 54篇 |
人才学 | 3篇 |
人口学 | 1089篇 |
丛书文集 | 57篇 |
理论方法论 | 1026篇 |
综合类 | 103篇 |
社会学 | 5634篇 |
统计学 | 2732篇 |
出版年
2023年 | 58篇 |
2022年 | 65篇 |
2021年 | 64篇 |
2020年 | 174篇 |
2019年 | 218篇 |
2018年 | 324篇 |
2017年 | 433篇 |
2016年 | 278篇 |
2015年 | 235篇 |
2014年 | 287篇 |
2013年 | 2208篇 |
2012年 | 417篇 |
2011年 | 315篇 |
2010年 | 289篇 |
2009年 | 211篇 |
2008年 | 254篇 |
2007年 | 255篇 |
2006年 | 261篇 |
2005年 | 246篇 |
2004年 | 194篇 |
2003年 | 207篇 |
2002年 | 216篇 |
2001年 | 321篇 |
2000年 | 288篇 |
1999年 | 269篇 |
1998年 | 204篇 |
1997年 | 169篇 |
1996年 | 219篇 |
1995年 | 189篇 |
1994年 | 199篇 |
1993年 | 168篇 |
1992年 | 201篇 |
1991年 | 213篇 |
1990年 | 196篇 |
1989年 | 170篇 |
1988年 | 193篇 |
1987年 | 179篇 |
1986年 | 141篇 |
1985年 | 176篇 |
1984年 | 180篇 |
1983年 | 156篇 |
1982年 | 122篇 |
1981年 | 97篇 |
1980年 | 97篇 |
1979年 | 121篇 |
1978年 | 93篇 |
1977年 | 81篇 |
1975年 | 63篇 |
1974年 | 67篇 |
1973年 | 60篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
In 1985, the National Institute on Drug Abuse (NIDA) funded an ethnographic research project in San Francisco to study the needle sharing behavior of injection drug users (IDUs). The goal of the research was to develop a strategy to slow the spread of HIV among this hidden and hard to reach population of drug users and their sexual partners. This small-scale project grew into a model intervention in which bleach, condoms, and street-based education by outreach workers were employed to inform IDUs of the risk of AIDS and of methods for protecting themselves. The "reach and teach bleach" model was adopted by NIDA and implemented in a number of American cities. This study describes the development of the model intervention, the adoption of the model by NIDA as part of its National AIDS Demonstration Research (NADR) project, and the political circumstances under which the city of San Francisco applied for the NADR grant. Drawing on Social Worlds/Arena theory, and based on extensive interviews and participant observation, a sociohistorical analysis examines the initial development, implementation, and disintegration of the model outreach project and the impact of the program on drug policy in the city of San Francisco. 相似文献
22.
This study examines the influence of the socialization of aggression among different gender and social class groupings and the influence of psychosocial stage on cognitive developmental play preferences among groups of school aged children. Observations of 143 play groups were coded for play preference (symbolic play, practice play, games with rules) and play performance (cooperative or competitive). Findings of the log-linear data analysis suggest a middle class and masculine bias in Piaget's cognitive model (i.e., that as age increases children prefer more games with rules). This model held only for middle class and affluent boys. Girls (both latency and prepubertal) and lower socioeconomic groups tended to prefer practice play. Girls were more likely to play cooperatively; boys more likely to play competitively. Implications for theory development and clinical practice are explored. 相似文献
23.
Research has repeatedly demonstrated that parent and child reports of child behavior and emotional functioning often do not agree in terms of symptom severity or even symptom presence. Given the potential clinical impact that discrepant reports may have on the therapeutic process, a significant amount of research has addressed the factors influencing this observed discrepancy. Traditionally, this research has evaluated the impact of demographic factors on mean differences and obtained correlation coefficients between parent and child reports. The current research improves upon previous research in this area in two ways. First, the current research uses parent and child measures with identical rather than similar items as is commonly found in previous research. Second, the current research moves beyond identifying demographic influences on discrepant reports by explaining observed discrepancies in terms of differences in parent and child perceptions of typical child behavior.David Carlston and Benjamin Ogles are affiliated with Department of Psychology, Ohio University, Athens, USA.Funding for this project was provided by the Ohio Department of Mental Health. 相似文献
24.
Stuart G. Baker Barnett S. Kramer 《Journal of the Royal Statistical Society. Series C, Applied statistics》2005,54(5):941-954
Summary. When evaluating potential interventions for cancer prevention, it is necessary to compare benefits and harms. With new study designs, new statistical approaches may be needed to facilitate this comparison. A case in point arose in a proposed genetic substudy of a randomized trial of tamoxifen versus placebo in asymptomatic women who were at high risk for breast cancer. Although the randomized trial showed that tamoxifen substantially reduced the risk of breast cancer, the harms from tamoxifen were serious and some were life threaten-ing. In hopes of finding a subset of women with inherited risk genes who derive greater bene-fits from tamoxifen, we proposed a nested case–control study to test some trial subjects for various genes and new statistical methods to extrapolate benefits and harms to the general population. An important design question is whether or not the study should target common low penetrance genes. Our calculations show that useful results are only likely with rare high penetrance genes. 相似文献
25.
Christian P. Robert Xiao-Li Meng Jesper Møller Jeffrey S Rosenthal C Jennison M. A Hurn F Al-Awadhi Peter McCullagh Christophe Andrieu Arnaud Doucet Petros Dellaportas Ioulia Papageorgiou Ricardo S Ehlers Elena A Erosheva Stephen E Fienberg Jonathan J Forster Roger C Gill Nial Friel Peter Green David Hastie R King Hans R Künsch N. A. Lazar C Osinski 《Journal of the Royal Statistical Society. Series B, Statistical methodology》2003,65(1):39-55
26.
S. Vansteelandt E. Goetghebeur 《Journal of the Royal Statistical Society. Series B, Statistical methodology》2003,65(4):817-835
Summary. We estimate cause–effect relationships in empirical research where exposures are not completely controlled, as in observational studies or with patient non-compliance and self-selected treatment switches in randomized clinical trials. Additive and multiplicative structural mean models have proved useful for this but suffer from the classical limitations of linear and log-linear models when accommodating binary data. We propose the generalized structural mean model to overcome these limitations. This is a semiparametric two-stage model which extends the structural mean model to handle non-linear average exposure effects. The first-stage structural model describes the causal effect of received exposure by contrasting the means of observed and potential exposure-free outcomes in exposed subsets of the population. For identification of the structural parameters, a second stage 'nuisance' model is introduced. This takes the form of a classical association model for expected outcomes given observed exposure. Under the model, we derive estimating equations which yield consistent, asymptotically normal and efficient estimators of the structural effects. We examine their robustness to model misspecification and construct robust estimators in the absence of any exposure effect. The double-logistic structural mean model is developed in more detail to estimate the effect of observed exposure on the success of treatment in a randomized controlled blood pressure reduction trial with self-selected non-compliance. 相似文献
27.
Lisa A. Gennetian Greg Duncan Virginia Knox Wanda Vargas Elizabeth Clark‐Kauffman Andrew S. London 《Journal of research on adolescence》2004,14(4):399-423
Using data from 8 random assignment studies and employing meta‐analytic techniques, this article provides systematic evidence that welfare and work policies targeted at low‐income parents have small adverse effects on some school outcomes among adolescents ages 12 to 18 years at follow‐up. These adverse effects were observed mostly for school performance outcomes and occurred in programs that required mothers to work or participate in employment‐related activities and those that encouraged mothers to work voluntarily. The most pronounced negative effects on school outcomes occurred for the group of adolescents who had a younger sibling, possibly because of the increased home and sibling care responsibilities they assumed as their mothers increased their employment. 相似文献
28.
Mr. Patrick J. Morrissette M.S.ED. 《Child and Adolescent Social Work Journal》1994,11(3):235-246
This paper proposes a developmental framework for foster parents and outlines four distinct growth stages. Such a framework can be of value to program administrators who are required to assess foster parent development during the crucial matching process. To draw a distinction between each developmental stage, specific instrumental tasks and indicators are outlined. 相似文献
29.
Jennifer S. Silk Amanda S. Morris Tomoe Kanaya Laurence Steinberg 《Journal of research on adolescence》2003,13(1):113-128
This article explores the relationship between parental psychological control and parental autonomy granting, and the relations between these constructs and indicators of adolescent psychosocial functioning, in a sample of 9,564 adolescents from grades 9 to 12. Participants completed a comprehensive parenting questionnaire as well as several measures of psychosocial adjustment. Confirmatory factor analyses of the parenting items revealed discrete factors for psychological control and autonomy granting, suggesting that these are distinct parenting constructs rather than opposite ends of a parental control continuum. Moreover, structural equation modeling showed that these factors were weakly correlated and differentially related to adolescent internalizing symptoms. Findings have implications for future conceptualization and measurement of psychological control and autonomy granting, and for research examining their effects on adolescent development. 相似文献
30.
Summary Based on 14 case studies of highly effective therapies and the reasons they succeeded less frequently than they could, we
propose a variety of steps to improve the health care system of the U.S.A. Whatever proposal emerges from current national
debates until innovations are shown to be safe and effective, they should not be supported; when slightly better technologies
are much more expensive than other good ones we need to consider appropriate choices carefully; simplified billing and bookkeping
would reduce our costs; when a technology is rapidly introduced cautionnary measures may be needed; tracking immunization
and repairing their omissions requires a new system; educational programs such as seen effective in hypertension should be
applied in other areas such as vaccination; in organ transplantation the nation should consider “presumed consent”; our payment
system sometimes creates perverse incentives and therefore needs review; and the preferences of the public in allocation of
health resources need to be discovered once the public is informed about the issues.
Research supported by Andrew W. Mellon Foundation. 相似文献