全文获取类型
收费全文 | 28109篇 |
免费 | 485篇 |
专业分类
管理学 | 3366篇 |
民族学 | 145篇 |
人才学 | 6篇 |
人口学 | 2500篇 |
丛书文集 | 163篇 |
教育普及 | 5篇 |
理论方法论 | 2546篇 |
现状及发展 | 1篇 |
综合类 | 336篇 |
社会学 | 14298篇 |
统计学 | 5228篇 |
出版年
2023年 | 142篇 |
2021年 | 147篇 |
2020年 | 403篇 |
2019年 | 622篇 |
2018年 | 651篇 |
2017年 | 920篇 |
2016年 | 651篇 |
2015年 | 503篇 |
2014年 | 633篇 |
2013年 | 5096篇 |
2012年 | 885篇 |
2011年 | 833篇 |
2010年 | 647篇 |
2009年 | 599篇 |
2008年 | 686篇 |
2007年 | 691篇 |
2006年 | 664篇 |
2005年 | 602篇 |
2004年 | 575篇 |
2003年 | 523篇 |
2002年 | 548篇 |
2001年 | 684篇 |
2000年 | 597篇 |
1999年 | 601篇 |
1998年 | 446篇 |
1997年 | 395篇 |
1996年 | 456篇 |
1995年 | 451篇 |
1994年 | 443篇 |
1993年 | 422篇 |
1992年 | 472篇 |
1991年 | 468篇 |
1990年 | 455篇 |
1989年 | 427篇 |
1988年 | 406篇 |
1987年 | 366篇 |
1986年 | 359篇 |
1985年 | 387篇 |
1984年 | 383篇 |
1983年 | 332篇 |
1982年 | 285篇 |
1981年 | 244篇 |
1980年 | 264篇 |
1979年 | 266篇 |
1978年 | 224篇 |
1977年 | 216篇 |
1976年 | 192篇 |
1975年 | 192篇 |
1974年 | 146篇 |
1973年 | 122篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
The authors consider the optimal design of sampling schedules for binary sequence data. They propose an approach which allows a variety of goals to be reflected in the utility function by including deterministic sampling cost, a term related to prediction, and if relevant, a term related to learning about a treatment effect To this end, they use a nonparametric probability model relying on a minimal number of assumptions. They show how their assumption of partial exchangeability for the binary sequence of data allows the sampling distribution to be written as a mixture of homogeneous Markov chains of order k. The implementation follows the approach of Quintana & Müller (2004), which uses a Dirichlet process prior for the mixture. 相似文献
132.
V. Scott H. Solberg Aaron H. Carlstrom Kimberly A. S. Howard Janice E. Jones 《The Career development quarterly》2007,55(4):313-327
Using cluster analysis, 789 predominately Latino and African American high school youth were classified into varying academic at‐risk profiles using self‐reported levels of academic confidence, motivation to attend school, perceived family support, connections with teachers and peers, and exposure to violence. Six clusters emerged, 5 of which were identified as “at‐risk.” The clusters were examined in relation to academic stress, health status, grades, and school retention. Exposure to violence was one distinguishing feature of youth identified as most vulnerable, vulnerable, and resilient; however, youth identified as resilient recorded better academic outcomes. 相似文献
133.
The importance of women on the bench and the influence of gender on judicial decision making has garnered much scholarly attention. We examine the voting behavior of male and female justices in 718 Fourth Amendment search and seizure votes cast on state Supreme Courts between 1980 and 2000. We find that women justices, controlling for institutional, political, and legal constraints, are more likely to rule in favor of the criminal defendant than their male brethren in cases decided after 1991 but not before. We also find women justices serving with female colleagues are more inclined to render liberal votes. We conclude the influence of gender may be evident in a wider variety of cases than those dealing with women's lives but that this influence is dependent upon the existence of a critical mass of women on the state court benches. 相似文献
134.
135.
Allison Zippay Ph.D. Anu Rangarajan Ph.D. 《Child and Adolescent Social Work Journal》2007,24(2):153-172
This article reports the results of a study that examined the ways in which current and recent TANF recipients assembled or
“packaged” their child care arrangements among formal and informal providers. The findings are drawn from in-person, in-depth
interviews with current and former welfare recipients. The study found that most of the respondents used multiple providers
within the category of informal child care for reasons including availability, the use of a network of social acquaintances as a
problem-solving resource, the need to accommodate irregular work hours, and personal trauma that contributed to a distrust
of strangers in formal settings. The findings can affect the efficacy of practice with TANF recipients by contributing to
social workers’ understanding of the context of decision-making regarding child care. 相似文献
136.
Susan A. Ostrander 《Nonprofit management & leadership》2007,18(2):237-253
This case study looks at changes in private foundation funding for higher education civic engagement from 1995 to 2005. The focus is three large, established foundations that were U.S. national leaders in supporting this activity during these years: Carnegie, Pew, and Kellogg. Data sources include (1) in‐depth conversations with four strategically placed foundation insiders and six nationally recognized campus leaders and (2) scans of Web sites of the three foundations that document the change in funding priorities over time, plus Web sites of the main campus initiatives supported and national campus civic engagement organizations such as Campus Compact. Research findings con‐ firm and specify other studies that suggest that foundations shift their funding priorities according to their perceived role as innovators, pressures to be accountable and show clear results, and their independence as private organizations. The article concludes by raising questions about private foundations generally in relation to issues of innovativeness, accountability, and independence. 相似文献
137.
FINNEY DJ 《Journal of the American Statistical Association》1948,43(244):566-571
138.
The probability of illness caused by very low doses of pathogens cannot generally be tested due to the numbers of subjects that would be needed, though such assessments of illness dose response are needed to evaluate drinking water standards. A predictive Bayesian dose-response assessment method was proposed previously to assess the unconditional probability of illness from available information and avoid the inconsistencies of confidence-based approaches. However, the method uses knowledge of the conditional dose-response form, and this form is not well established for the illness endpoint. A conditional parametric dose-response function for gastroenteric illness is proposed here based on simple numerical models of self-organized host-pathogen systems and probabilistic arguments. In the models, illnesses terminate when the host evolves by processes of natural selection to a self-organized critical value of wellness. A generalized beta-Poisson illness dose-response form emerges for the population as a whole. Use of this form is demonstrated in a predictive Bayesian dose-response assessment for cryptosporidiosis. Results suggest that a maximum allowable dose of 5.0 x 10(-7) oocysts/exposure (e.g., 2.5 x 10(-7) oocysts/L water) would correspond with the original goals of the U.S. Environmental Protection Agency Surface Water Treatment Rule, considering only primary illnesses resulting from Poisson-distributed pathogen counts. This estimate should be revised to account for non-Poisson distributions of Cryptosporidium parvum in drinking water and total response, considering secondary illness propagation in the population. 相似文献
139.
140.
D. R. Cox 《Journal of the Royal Statistical Society. Series A, (Statistics in Society)》2003,166(2):241-246
Summary. Possible health hazards from mobile phones arise from the use of the phones themselves and via the base stations that relay signals. Except for an increase in traffic accidents induced by the use of mobile phones in cars the evidence for a health hazard is at most indirect, but it cannot be entirely dismissed; the phones have not been widely used for sufficiently long for direct epidemiological studies to have high sensitivity for detecting any induced incidence of cancer, for example. The background and evidence are briefly reviewed and the steps taken in the UK to make information widely available described. 相似文献