全文获取类型
收费全文 | 20346篇 |
免费 | 544篇 |
国内免费 | 15篇 |
专业分类
管理学 | 2696篇 |
民族学 | 107篇 |
人才学 | 1篇 |
人口学 | 1847篇 |
丛书文集 | 169篇 |
理论方法论 | 1769篇 |
综合类 | 782篇 |
社会学 | 9989篇 |
统计学 | 3545篇 |
出版年
2023年 | 103篇 |
2021年 | 144篇 |
2020年 | 316篇 |
2019年 | 397篇 |
2018年 | 531篇 |
2017年 | 730篇 |
2016年 | 500篇 |
2015年 | 380篇 |
2014年 | 483篇 |
2013年 | 3282篇 |
2012年 | 706篇 |
2011年 | 692篇 |
2010年 | 557篇 |
2009年 | 488篇 |
2008年 | 528篇 |
2007年 | 579篇 |
2006年 | 562篇 |
2005年 | 505篇 |
2004年 | 419篇 |
2003年 | 384篇 |
2002年 | 404篇 |
2001年 | 520篇 |
2000年 | 455篇 |
1999年 | 425篇 |
1998年 | 314篇 |
1997年 | 288篇 |
1996年 | 275篇 |
1995年 | 271篇 |
1994年 | 260篇 |
1993年 | 249篇 |
1992年 | 313篇 |
1991年 | 291篇 |
1990年 | 288篇 |
1989年 | 260篇 |
1988年 | 250篇 |
1987年 | 271篇 |
1986年 | 229篇 |
1985年 | 255篇 |
1984年 | 276篇 |
1983年 | 263篇 |
1982年 | 237篇 |
1981年 | 208篇 |
1980年 | 190篇 |
1979年 | 211篇 |
1978年 | 179篇 |
1977年 | 153篇 |
1976年 | 152篇 |
1975年 | 173篇 |
1974年 | 137篇 |
1973年 | 110篇 |
排序方式: 共有10000条查询结果,搜索用时 125 毫秒
11.
12.
Objectives: In the United States, HIV continues to disproportionately affect men who have sex with men. One promising area of research that may inform the development of behavioral interventions among male–male couples is within the realm of sexual agreements. Methods: The purpose of our analysis was to determine whether respondents who report having an open agreement or an agreement breakage also report a higher incidence of recent (within the previous 12 months) intimate-partner violence (IPV) compared to respondents who report having a monogamous agreement or no agreement breakage after controlling for demographic variables. Results: Results showed that men who have an open agreement are less likely to report recent physical IPV. Conclusions: The results highlight the need to develop dyadic behavior interventions that address sexual agreements and stress management. 相似文献
13.
Oliveira Flávio G. Tapisso Joaquim T. von Merten Sophie Rychlik Leszek Fonseca Paulo J. Mathias Maria da Luz 《Urban Ecosystems》2021,24(5):851-862
Urban Ecosystems - The development of urban areas imposes challenges that wildlife must adapt to in order to persist in these new habitats. One of the greatest changes brought by urbanization has... 相似文献
14.
Theory and Society - The massive expansion of US higher education after World War II is a sociological puzzle: a spectacular feat of state capacity-building in a highly federated polity. Prior... 相似文献
15.
Proportional hazards are a common assumption when designing confirmatory clinical trials in oncology. This assumption not only affects the analysis part but also the sample size calculation. The presence of delayed effects causes a change in the hazard ratio while the trial is ongoing since at the beginning we do not observe any difference between treatment arms, and after some unknown time point, the differences between treatment arms will start to appear. Hence, the proportional hazards assumption no longer holds, and both sample size calculation and analysis methods to be used should be reconsidered. The weighted log‐rank test allows a weighting for early, middle, and late differences through the Fleming and Harrington class of weights and is proven to be more efficient when the proportional hazards assumption does not hold. The Fleming and Harrington class of weights, along with the estimated delay, can be incorporated into the sample size calculation in order to maintain the desired power once the treatment arm differences start to appear. In this article, we explore the impact of delayed effects in group sequential and adaptive group sequential designs and make an empirical evaluation in terms of power and type‐I error rate of the of the weighted log‐rank test in a simulated scenario with fixed values of the Fleming and Harrington class of weights. We also give some practical recommendations regarding which methodology should be used in the presence of delayed effects depending on certain characteristics of the trial. 相似文献
16.
Public Organization Review - 相似文献
17.
吕铖钢 《北京理工大学学报(社会科学版)》2021,23(2):152-160
税法中不确定概念下的理论空间以及税务行政的实践需求共同营造了税务行政裁量的制度空间,而不规范的税务行政裁量则为不规范的税收执法提供了操作机会。通过对税法文本中不确定概念理论缘由的寻求,以及税收征管中实践动因的梳理,税务行政裁量权的规范化确有必要性。为达成税法运行各司其职中的彼此制衡,有必要强化比例性原则在税务行政裁量中的运用,以此限制税权介入纳税人私域的范围与限度,并提供明确化的宏观指引;利用行政裁量基准“行政自制”与“规则之治”的双重品质,借助标准化的文本修正,为规范化的税收执法预设行为轨迹、构建外在制约并压缩裁量空间;以纳税人的同意权为基础,设计符合税法特殊性的程序规则,形成立体化的纳税人救济路径。最终形成税务行政裁量权积极运作与规范运行的制度环境。 相似文献
18.
de Jong Petra W. Caarls Kim de Valk Helga A. G. 《Population research and policy review》2022,41(2):671-694
Population Research and Policy Review - The welfare state can be perceived as a safety net which helps individuals adjust to situations of risk or transition. Starting from this idea of the welfare... 相似文献
19.
Witkower Zachary Tracy Jessica L. Pun Anthea Baron Andrew S. 《Journal of Nonverbal Behavior》2021,45(4):505-518
Journal of Nonverbal Behavior - Past research has demonstrated that children understand distinct emotion concepts and can accurately recognize facial expressions of distinct emotions by a young... 相似文献
20.