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   25480篇
  免费   1452篇
各国政治   1069篇
工人农民   1126篇
世界政治   1863篇
外交国际关系   831篇
法律   16994篇
中国共产党   2篇
中国政治   151篇
政治理论   4769篇
综合类   127篇
  2021年   146篇
  2020年   503篇
  2019年   564篇
  2018年   710篇
  2017年   752篇
  2016年   844篇
  2015年   644篇
  2014年   697篇
  2013年   2584篇
  2012年   650篇
  2011年   753篇
  2010年   709篇
  2009年   749篇
  2008年   732篇
  2007年   708篇
  2006年   729篇
  2005年   638篇
  2004年   631篇
  2003年   534篇
  2002年   600篇
  2001年   1005篇
  2000年   922篇
  1999年   699篇
  1998年   392篇
  1997年   308篇
  1996年   299篇
  1995年   289篇
  1994年   298篇
  1993年   295篇
  1992年   466篇
  1991年   478篇
  1990年   461篇
  1989年   454篇
  1988年   468篇
  1987年   421篇
  1986年   491篇
  1985年   478篇
  1984年   379篇
  1983年   358篇
  1982年   268篇
  1981年   258篇
  1980年   214篇
  1979年   322篇
  1978年   180篇
  1977年   159篇
  1976年   136篇
  1975年   130篇
  1974年   185篇
  1973年   139篇
  1972年   130篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
961.
This article analyses welfare impacts of fertiliser adoption using data collected from 838 cocoa farm households in the four key cocoa-producing regions in Ghana. Using propensity score matching (PSM), the study indicates that application of fertiliser leads to significant gains in farm yields, farm income, consumption expenditure, consumption expenditure per capita, and value of productive farm assets. The article concludes that cocoa-specific programmes such as Cocoa High Technology (Cocoa Hi-tech), initiated to intensify the application of improved farm technologies such as fertiliser, should be strengthened through effective and efficient management systems.  相似文献   
962.
963.
This article explores the potential of using children’s perceptions of distance to reflect a gendered understanding of remoteness. Data collected from 1,549 children in Tanzania concerning their perceptions of remoteness in relation to accessibility of school, health care, and water resources were analysed in reference to their impact on school attendance and performance. Gendered variability in perceived distances to services by children may indicate that remoteness is as much of a social issue as it is a geographic phenomenon, in that girls perceive distance and time between home and destination to be further than boys who travel approximately the same distance.  相似文献   
964.
Following 9/11, Al-Qaeda-orchestrated plots were considered the greatest threat to Western security and sparked the coalition’s war on terror. Close to a decade later, the post-9/11 threat landscape had shifted significantly, leading then CIA-director Leon Panetta to describe “the lone-wolf strategy” as the main threat to the United States. Subsequent lone-actor attacks across the West, including the cities of London, Nice, Berlin, Stockholm, Ottawa and Charleston, further entrenched perspectives of a transformed security landscape in the “after, after-9/11” world. The unique features of lone-actor terrorism, including the challenges of interdiction and potential of copycat attacks, mean that the media is likely to play a particularly important role in shaping the reactions of the public, affected communities and copycat attackers. This article presents findings from a content analysis of British and Danish newspaper reporting of lone-actor terrorism between January 2010 and February 2015. The study highlights that lone-actor terrorism is framed, with national variations, as a significant and increasing problem in both countries; that Islamist lone-actors are often represented as distinct from far-right lone-actors; and that some reporting, despite relatively limited amplification of specific terrorist messages, potentially aids lone-actors by detailing state vulnerabilities to attacks.  相似文献   
965.

Young adulthood represents a developmental period with disproportionately heightened risk of losing a job. Young adult unemployment has been linked to increased mental health problems, at least in the short term. However, their possible long-term impacts, often referred as “scarring effects,” have been understudied, possibly underestimating the magnitude of mental health burden that young adult unemployment generates. This longitudinal study examined whether duration of unemployment during young adulthood is associated with later mental health disorders, after accounting for mental and behavioral health problems in childhood. Furthermore, the current study investigated whether childhood neighborhood characteristics affect this association and if so, in what specific functional ways. Data were drawn from a longitudinal study of developmental outcomes in a community sample in Seattle. Data collection began in 1985 when study participants were elementary students and involved yearly assessments in childhood and adolescence (ages 10–16) and then biennial or triennial assessments (ages 18–39; N?=?677 at age 39; 47% European American, 26% African American, 22% Asian American, and 5% Native American; 49% female). The current study findings suggest that duration of unemployment across young adulthood increased mental health problems at age 39, regardless of gender. Childhood neighborhood characteristics, particularly their positive aspect, exerted independent impacts on adult mental health problems beyond unemployment experiences across young adulthood. The current findings indicate a needed shift in service profiles for unemployed young adults—a comprehensive approach that not only facilitates reemployment but also addresses mental health needs to help them to cope with job loss. Further, the present study findings suggest that childhood neighborhoods, particularly positive features such as positive neighborhood involvement, may represent concrete and malleable prevention targets that can curb mental health problems early in life.

  相似文献   
966.
Journal of Youth and Adolescence - The development of social behavior could be affected by stressful parenting. The mineralocorticoid receptor, one of the two main receptors for the stress hormone...  相似文献   
967.
Journal of Youth and Adolescence - In the original publication, the legends for Figs 4 and 5 were incorrect, such that each regression line was mislabeled with the incorrect country. Below are the...  相似文献   
968.

Drawing from Race-Based Traumatic Stress theory, the present study examined whether traumatic stress and depressive symptoms differentially help explain the relation between racial/ethnic discrimination and suicidal ideation across gender and racial/ethnic groups. A racially/ethnically diverse group of emerging adults (N?=?1344; Mage?=?19.88, SD?=?2.25; 72% female; 46% Hispanic) completed a battery of self-report measures. A cross-sectional design was employed with a series of hierarchical linear regression models and bootstrapping procedures to examine the direct and indirect relation between racial/ethnic discrimination and suicidal ideation through traumatic stress and depressive symptoms across gender and race/ethnicity. The findings suggest an indirect relation through depressive symptoms, but not traumatic stress, and a serial indirect relation through traumatic stress to depressive symptoms in young women and young men, the latter of which was stronger in young women. The indirect relations did not vary by racial/ethnic group. Cumulative experiences of racial/ethnic discrimination may impact suicide-related risk via increases in psychiatric symptomology (i.e., traumatic stress and depressive symptoms), particularly in young women. Racial/ethnic discrimination experiences should be accounted for as a potential source of psychological distress in the assessment, diagnosis, and treatment of suicidal thoughts and behavior, especially among young women endorsing traumatic stress and depressive symptoms. Further research is warranted to better understand the gender difference in the relation between racial/ethnic discrimination and suicide-related risk.

  相似文献   
969.
As transgender and gender-expansive (TGE) youth and young adults (YYA) navigate challenging environments, they often seek spaces for safety and acceptance. This study explores ways in which a group of TGE YYA who were engaged with a community-based service organization make sense of their experiences, challenges, and successes in ways that illuminate the factors and processes associated with resilience. Secondary data analysis was conducted on qualitative responses from 85 TGE YYA ages 13–24. The themes that emerged provide insight into the ways community-based programs and providers can understand and support the resilience of TGE YYA.  相似文献   
970.
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