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   8828篇
  免费   249篇
  国内免费   3篇
管理学   1174篇
民族学   52篇
人才学   1篇
人口学   839篇
丛书文集   63篇
教育普及   1篇
理论方法论   855篇
综合类   137篇
社会学   4190篇
统计学   1768篇
  2023年   42篇
  2021年   51篇
  2020年   133篇
  2019年   210篇
  2018年   195篇
  2017年   327篇
  2016年   217篇
  2015年   173篇
  2014年   201篇
  2013年   1683篇
  2012年   285篇
  2011年   279篇
  2010年   188篇
  2009年   236篇
  2008年   240篇
  2007年   229篇
  2006年   230篇
  2005年   213篇
  2004年   201篇
  2003年   179篇
  2002年   214篇
  2001年   181篇
  2000年   173篇
  1999年   177篇
  1998年   143篇
  1997年   136篇
  1996年   147篇
  1995年   144篇
  1994年   120篇
  1993年   118篇
  1992年   127篇
  1991年   124篇
  1990年   126篇
  1989年   122篇
  1988年   89篇
  1987年   85篇
  1986年   109篇
  1985年   112篇
  1984年   111篇
  1983年   85篇
  1982年   73篇
  1981年   74篇
  1980年   77篇
  1979年   88篇
  1978年   80篇
  1977年   60篇
  1976年   61篇
  1975年   59篇
  1974年   51篇
  1971年   45篇
排序方式: 共有9080条查询结果,搜索用时 15 毫秒
1.
2.
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   
3.
Presidential elections are often seen as referendums on the health of the economy; however, little evidence exists on the president's ability to influence gross domestic product (GDP). This study examines the effect of the incentive to be reelected and the resulting increase in presidential effort on GDP growth. Growth is found to rise in reelection years for first‐term presidents after 1932 and to fall in election years before 1932, when reelection was uncommon, and for second‐term presidents generally. This effect is largest for high‐quality presidents—who probably have the highest return to effort—and is spread across multiple sectors of the economy. (JEL D78, D72, E32, J24)  相似文献   
4.
5.
Abstract

In general, survival data are time-to-event data, such as time to death, time to appearance of a tumor, or time to recurrence of a disease. Models for survival data have frequently been based on the proportional hazards model, proposed by Cox. The Cox model has intensive application in the field of social, medical, behavioral and public health sciences. In this paper we propose a more efficient sampling method of recruiting subjects for survival analysis. We propose using a Moving Extreme Ranked Set Sampling (MERSS) scheme with ranking based on an easy-to-evaluate baseline auxiliary variable known to be associated with survival time. This paper demonstrates that this approach provides a more powerful testing procedure as well as a more efficient estimate of hazard ratio than that based on simple random sampling (SRS). Theoretical derivation and simulation studies are provided. The Iowa 65+ Rural study data are used to illustrate the methods developed in this paper.  相似文献   
6.
An understanding of the current right‐wing national and transnational social movements can benefit from comparing them to the global and national conditions operating during their last appearance in the first half of the twentieth century and by carefully comparing twentieth‐century fascism with the neofascist and right‐wing populist movements that have been emerging in the twenty‐first century. This allows us to assess the similarities and differences, and to gain insights about what could be the consequences of the reemergence of populist nationalism and fascist movements. Our study uses the comparative evolutionary world‐systems perspective to study the Global Right from 1800 to the present. We see fascism as a form of capitalism that emerges when the capitalist project is in crisis. World historical waves of right‐wing populism and fascism are caused by the cycles of globalization and deglobalization, the rise and fall of hegemonic core powers, long business cycles (the Kondratieff wave), and interactions with both Centrist Liberalism and the Global Left. We consider how crises of the global capitalist system have produced right‐wing backlashes in the past, and how a future terminal crisis of capitalism could lead to a reemergence of a new form of authoritarian global governance or a reorganized global democracy in the future.  相似文献   
7.
8.
Popular commentators on marriage and the family often interpret the increase in heterosexual couples living together without marrying as reduced willingness to create and honour life‐long partnerships. Survey and in‐depth interviews with samples of 20–29 year olds living in an urban area of Scotland finds little support for the postulated link between growing cohabitation and a weakened sense of commitment to long‐term arrangements. Most of the cohabiting couples strongly stressed their ‘commitment’. Socially acceptable vocabularies of motive undoubtedly influenced answers but interviews helped to explore deeper meanings. Many respondents’ views were consistent with previous research predictions of a weakening sense of any added value of marriage. At the same time, some respondents continued to stress the social significance of the distinction between marriage and cohabitation, consistent with research interpreting cohabitation as a ‘try and see’ strategy part‐way to the perceived full commitment of marriage. The notion that ‘marriage is better for children’ continued to have support among respondents. While, on average, cohabiting couples had lower incomes and poorer employment situations than married couples, only very extreme adverse circumstances were presented as making marriage ‘too risky’. Pregnancy‐provoked cohabitation was not always in this category. Cohabitation was maintained because marriage would ‘make no difference’ or because they ‘had not yet got round to’ marriage. Most respondents were more wary of attempting to schedule or plan in their personal life than in other domains and cohabitees’ attitudes to partnership, including their generally ‘committed’ approach, do not explain the known greater vulnerability of this group to dissolution.  相似文献   
9.
Acculturative stress in the adjustment of immigrant families   总被引:1,自引:0,他引:1  
This study reviews the issue of acculturative stress in immigrant families. Acculturative stress includes behaviors experienced by immigrants that are a direct consequence of the process of acculturation and adaptation to a new society. A number of stressors impacting on the acculturation of immigrant families is discussed. These stressors include lack of English language skills, employment and economic status, educational background, family life, and sociopolitical and immigration status.  相似文献   
10.
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