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   23698篇
  免费   714篇
  国内免费   3篇
管理学   3027篇
民族学   152篇
人才学   12篇
人口学   2139篇
丛书文集   141篇
教育普及   2篇
理论方法论   2388篇
现状及发展   1篇
综合类   282篇
社会学   12003篇
统计学   4268篇
  2023年   125篇
  2022年   101篇
  2021年   131篇
  2020年   377篇
  2019年   601篇
  2018年   631篇
  2017年   811篇
  2016年   633篇
  2015年   484篇
  2014年   574篇
  2013年   3980篇
  2012年   842篇
  2011年   782篇
  2010年   608篇
  2009年   558篇
  2008年   658篇
  2007年   695篇
  2006年   634篇
  2005年   605篇
  2004年   584篇
  2003年   531篇
  2002年   534篇
  2001年   561篇
  2000年   514篇
  1999年   478篇
  1998年   405篇
  1997年   362篇
  1996年   372篇
  1995年   348篇
  1994年   356篇
  1993年   331篇
  1992年   372篇
  1991年   345篇
  1990年   306篇
  1989年   306篇
  1988年   294篇
  1987年   266篇
  1986年   257篇
  1985年   294篇
  1984年   286篇
  1983年   273篇
  1982年   221篇
  1981年   196篇
  1980年   212篇
  1979年   209篇
  1978年   168篇
  1977年   166篇
  1976年   164篇
  1975年   139篇
  1974年   128篇
排序方式: 共有10000条查询结果,搜索用时 318 毫秒
11.
Social media is pervasive in the lives of young people, and this paper critically analyses how politically engaged young people integrate social media use into their existing organisations and political communications. This qualitative research project studied how young people from a broad range of existing political and civic groups use social media for sharing information, mobilisation and, increasingly, as a means to redefine political action and political spaces. Twelve in-person focus groups were conducted in Australia, the USA and the UK with matched affinity groups based on university campuses. The groups were of four types: party political group, issue-based group, identity-based group and social group. Our focus group findings suggest that this in-depth approach to understanding young people's political engagement reveals important group-based differences emerging in young people's citizenship norms: between the dutiful allegiance to formal politics and a more personalised, self-actualising preference for online, discursive forms of political engagement and organising. The ways in which political information is broadcast, shared and talked about on social media by engaged young people demonstrate the importance of communicative forms of action for the future of political engagement and connective action.  相似文献   
12.
This article analyzes the development prospects and problems for the Eurasian Economic Union (EAEU). It examines issues of integration within the EAEU, as well as interactions with other countries, both CIS (Commonwealth of Independent States) and non-CIS. The main problem of integration within the EAEU is the dominance of redistributive motives over productive ones. This article assesses the extent of Russian oil and gas transfers to EAEU partners and the impact of tax maneuvers on their size. It shows that the creation of mechanisms for redistributing profits within the EAEU will allow a positive economic effect to materialize from free trade agreements with non-CIS countries. The article assesses the risks for the EAEU related to Russia’s introduction of a unilateral ban on food imports from countries on the sanctions list and to the possible establishment of tariffs on trade with Ukraine.  相似文献   
13.
Understanding the risk of biological invasions associated with particular transport pathways and source regions is critical for implementing effective biosecurity management. This may require both a model for physical connectedness between regions, and a measure of environmental similarity, so as to quantify the potential for a species to be transported from a given region and to survive at a destination region. We present an analysis of integrated biosecurity risk into Australia, based on flights and shipping data from each global geopolitical region, and an adaptation of the “range bagging” method to determine environmental matching between regions. Here, we describe global patterns of environmental matching and highlight those regions with many physical connections. We classify patterns of global invasion risk (high to low) into Australian states and territories. We validate our analysis by comparison with global presence data for 844 phytophagous insect pest species, and produce a list of high‐risk species not previously known to be present in Australia. We determined that, of the insect pest species used for validation, the species most likely to be present in Australia were those also present in geopolitical regions with high transport connectivity to Australia, and those regions that were geographically close, and had similar environments.  相似文献   
14.
The generalized half-normal (GHN) distribution and progressive type-II censoring are considered in this article for studying some statistical inferences of constant-stress accelerated life testing. The EM algorithm is considered to calculate the maximum likelihood estimates. Fisher information matrix is formed depending on the missing information law and it is utilized for structuring the asymptomatic confidence intervals. Further, interval estimation is discussed through bootstrap intervals. The Tierney and Kadane method, importance sampling procedure and Metropolis-Hastings algorithm are utilized to compute Bayesian estimates. Furthermore, predictive estimates for censored data and the related prediction intervals are obtained. We consider three optimality criteria to find out the optimal stress level. A real data set is used to illustrate the importance of GHN distribution as an alternative lifetime model for well-known distributions. Finally, a simulation study is provided with discussion.  相似文献   
15.
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   
16.
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   
17.
Statistics and Computing - This article focuses on the challenging problem of efficiently detecting changes in mean within multivariate data sequences. Multivariate changepoints can be detected by...  相似文献   
18.
19.
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   
20.
This paper considers whether gains made by shareholders from corporate takeovers are achieved at the expense of employees, as proposed by the ‘wealth transfer’ perspective. It analyses the contribution of employee lay‐offs, along with employment and wage changes, to the takeover premium and abnormal share price movements. The analysis draws on a unique dataset of British takeovers, combining documentary, share price and accounting data. The results show that lay‐offs planned at the takeover have either no effect or adverse effects on shareholder returns. Wages growth is positively, not inversely, related to shareholder returns from the second year after the takeover, whilst positive employment changes have a similar effect in the following year. Closer scrutiny indicates that labour and shareholders share gains when the firm does well, but share pain when it does not. There is evidence, therefore, that labour and shareholder interests can be complementary, rather than antagonistic, after takeovers.  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