全文获取类型
收费全文 | 22378篇 |
免费 | 534篇 |
国内免费 | 2篇 |
专业分类
管理学 | 3000篇 |
民族学 | 112篇 |
人才学 | 4篇 |
人口学 | 1970篇 |
丛书文集 | 145篇 |
教育普及 | 2篇 |
理论方法论 | 2164篇 |
综合类 | 549篇 |
社会学 | 11284篇 |
统计学 | 3684篇 |
出版年
2021年 | 113篇 |
2020年 | 326篇 |
2019年 | 450篇 |
2018年 | 481篇 |
2017年 | 700篇 |
2016年 | 518篇 |
2015年 | 410篇 |
2014年 | 485篇 |
2013年 | 3687篇 |
2012年 | 703篇 |
2011年 | 631篇 |
2010年 | 467篇 |
2009年 | 473篇 |
2008年 | 501篇 |
2007年 | 541篇 |
2006年 | 467篇 |
2005年 | 594篇 |
2004年 | 521篇 |
2003年 | 424篇 |
2002年 | 463篇 |
2001年 | 558篇 |
2000年 | 498篇 |
1999年 | 493篇 |
1998年 | 358篇 |
1997年 | 345篇 |
1996年 | 356篇 |
1995年 | 325篇 |
1994年 | 339篇 |
1993年 | 314篇 |
1992年 | 363篇 |
1991年 | 363篇 |
1990年 | 348篇 |
1989年 | 349篇 |
1988年 | 314篇 |
1987年 | 313篇 |
1986年 | 285篇 |
1985年 | 311篇 |
1984年 | 344篇 |
1983年 | 320篇 |
1982年 | 277篇 |
1981年 | 220篇 |
1980年 | 237篇 |
1979年 | 271篇 |
1978年 | 223篇 |
1977年 | 193篇 |
1976年 | 186篇 |
1975年 | 191篇 |
1974年 | 177篇 |
1973年 | 150篇 |
1972年 | 118篇 |
排序方式: 共有10000条查询结果,搜索用时 20 毫秒
1.
Almog-Bar Michal Ashkenazi-Anor Mayrav Hersberger-Langloh Sophie E. Compion Sara Butcher Jacqueline 《Voluntas: International Journal of Voluntary and Nonprofit Organizations》2022,33(3):483-496
VOLUNTAS: International Journal of Voluntary and Nonprofit Organizations - Age has long been understood as a strong demographic determinant of volunteering. However, to date, limited literature... 相似文献
2.
3.
Cancho Vicente G. Macera Márcia A. C. Suzuki Adriano K. Louzada Francisco Zavaleta Katherine E. C. 《Lifetime data analysis》2020,26(2):221-244
Lifetime Data Analysis - Frailty models are generally used to model heterogeneity between the individuals. The distribution of the frailty variable is often assumed to be continuous. However, there... 相似文献
4.
5.
Prior research suggests that nonprofits are flexible and possess multiple identities, although we know less about how transformative changes, such as mergers, shape nonprofit identity. This qualitative study draws upon in‐depth interviews from 13 nonprofit merger cases to explore factors that influence postmerger identity and integration. In particular, we focus on the roles of organizational similarity and relationships, program and personnel retention, and rebranding. Ultimately, we derive a typology of postmerger integration in nonprofits and suggest that postmerger identity may be classified in terms of absorption, preservation, or creation. Implications for nonprofit leaders are discussed. 相似文献
6.
Stephen J. Ruberg Frank E. Harrell Jr. Margaret Gamalo-Siebers Lisa LaVange J. Jack Lee Karen Price 《The American statistician》2019,73(1):319-327
ABSTRACTThe cost and time of pharmaceutical drug development continue to grow at rates that many say are unsustainable. These trends have enormous impact on what treatments get to patients, when they get them and how they are used. The statistical framework for supporting decisions in regulated clinical development of new medicines has followed a traditional path of frequentist methodology. Trials using hypothesis tests of “no treatment effect” are done routinely, and the p-value < 0.05 is often the determinant of what constitutes a “successful” trial. Many drugs fail in clinical development, adding to the cost of new medicines, and some evidence points blame at the deficiencies of the frequentist paradigm. An unknown number effective medicines may have been abandoned because trials were declared “unsuccessful” due to a p-value exceeding 0.05. Recently, the Bayesian paradigm has shown utility in the clinical drug development process for its probability-based inference. We argue for a Bayesian approach that employs data from other trials as a “prior” for Phase 3 trials so that synthesized evidence across trials can be utilized to compute probability statements that are valuable for understanding the magnitude of treatment effect. Such a Bayesian paradigm provides a promising framework for improving statistical inference and regulatory decision making. 相似文献
7.
8.
Journal of Nonverbal Behavior - Age-related deficits are often observed in emotion categorization tasks that include negative emotional expressions like anger, fear, and sadness. Stimulus... 相似文献
9.
Random effects regression mixture models are a way to classify longitudinal data (or trajectories) having possibly varying lengths. The mixture structure of the traditional random effects regression mixture model arises through the distribution of the random regression coefficients, which is assumed to be a mixture of multivariate normals. An extension of this standard model is presented that accounts for various levels of heterogeneity among the trajectories, depending on their assumed error structure. A standard likelihood ratio test is presented for testing this error structure assumption. Full details of an expectation-conditional maximization algorithm for maximum likelihood estimation are also presented. This model is used to analyze data from an infant habituation experiment, where it is desirable to assess whether infants comprise different populations in terms of their habituation time. 相似文献
10.
As important members of research teams, statisticians bear an ethical responsibility to analyze, interpret, and report data honestly and objectively. One way of reinforcing ethical responsibilities is through required courses covering a variety of ethics-related topics at the graduate level. We assessed ethics requirements for graduate-level statistics training programs in the United States for the 2013–2014 academic year using the websites of 88 universities, examining 103 biostatistics programs, and 136 statistics degree programs. We categorized programs’ ethics training requirements as required or not required. Thirty-one (35.1%) universities required an ethics course for at least some degree students. Sixty-two (25.5%) degree programs required an ethics course for at least some students. The majority (77.4%) of required courses were worth 0 or 1 credit. Of the 177 programs without an ethics requirement, 19 (10.7%) listed an ethics elective. Although a single ethics course is insufficient for instilling an ethical approach to science, degree programs that model expectations through coursework point to the value of ethics in science. More training programs should prepare statisticians to consider the ethical dimensions of their work through required coursework. Supplementary materials for this article are available online. 相似文献