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   1427篇
  免费   75篇
各国政治   103篇
工人农民   71篇
世界政治   117篇
外交国际关系   118篇
法律   748篇
中国政治   11篇
政治理论   320篇
综合类   14篇
  2023年   20篇
  2022年   25篇
  2021年   19篇
  2020年   43篇
  2019年   56篇
  2018年   52篇
  2017年   71篇
  2016年   75篇
  2015年   43篇
  2014年   65篇
  2013年   210篇
  2012年   63篇
  2011年   51篇
  2010年   43篇
  2009年   53篇
  2008年   49篇
  2007年   66篇
  2006年   50篇
  2005年   61篇
  2004年   43篇
  2003年   41篇
  2002年   47篇
  2001年   21篇
  2000年   22篇
  1999年   25篇
  1998年   16篇
  1997年   9篇
  1996年   12篇
  1995年   14篇
  1994年   9篇
  1993年   3篇
  1992年   22篇
  1991年   7篇
  1990年   9篇
  1989年   12篇
  1988年   9篇
  1987年   8篇
  1986年   7篇
  1985年   6篇
  1984年   3篇
  1983年   7篇
  1982年   4篇
  1981年   3篇
  1980年   4篇
  1975年   3篇
  1974年   2篇
  1973年   2篇
  1969年   3篇
  1966年   3篇
  1955年   1篇
排序方式: 共有1502条查询结果,搜索用时 15 毫秒
41.
Food production has been changing significantly in recent years as a result of climate change and of growing demand for food. This article aims to understand the link between food security and international security in the context of climate change, applying a systematic and qualitative analysis of the literature using the bibliometric method. This research observes that climate change tends to affect agricultural productivity, exposing societies to risk and the need for migration. However, good governance, together with international cooperation, can reduce the hazards of food insecurity, strengthening ties between countries and stimulating a fairer and more inclusive form of international trade.  相似文献   
42.
43.
44.
The pandemic of Covid-19 has exposed the veins of inequality in Latin America. With a socioeconomic disaster looming, social emergency policies seemed inevitable. Yet while governments argue over the continuity of such policies and whether the fiscal rules in place should be respected, no sustainable response has come out. This essay problematises whether the pandemic could represent a critical juncture to forge ahead with political narratives that highlight tax exemptions and privileges enjoyed by the rich. We analyse the mitigation measures adopted by Argentina, Brazil, Chile and Uruguay and their repercussions on the debate surrounding progressive tax reforms to fund social schemes.  相似文献   
45.
DNA is one of the fastest growing tools in forensic sciences, increasing reliability in forensic reports and judgments. The use of DNA has increased in different areas of the forensic sciences, such as investigation of plant species, where plastid DNA has been used to elucidate and generate evidence in cases of traceability of genetically modified and controlled plants. Even with several advances and the practice of using DNA in forensic investigations, there are just few studies related to the identification of genetic tools for the characterization of drug and nondrug-types of Cannabis. Herein, the whole plastomes of two drug-type Cannabis are presented and have their structures compared with other Cannabis plastomes deposited in the GenBank, focusing in the forensic use of plastome sequences. The plastomes of Cannabis sativa “Brazuka” and of the hybrid Cannabis AK Royal Automatic presented general structure that does not differs from the reported for other C. sativa cultivars. A phylogenomic analyses grouped C. sativa “Brazuka” with the nondrug C. sativa cultivars, while the hybrid Cannabis AK Royal Automatic placed isolated, basal to this group. This suggests that the analysis of plastomes is useful toward genetic identification of hybrids in relation to C. sativa.  相似文献   
46.
47.

Empathy, which is the ability to feel concern for and to understand others’ feelings, is thought to develop in high quality relationships with parent and peers, but also to facilitate the quality of these relationships. While a wide literature has addressed this aspect, the heterogeneity of primary studies, in which different indicators of relationship quality (e.g., support, conflict) and empathy (i.e., affective and cognitive) have been examined, makes it difficult to draw conclusive answers. Therefore, it remained ambiguous how parent–child and peer relationship quality are associated with adolescents’ empathy. In order to increase the understanding of these associations, a multilevel meta-analysis was performed, which allowed for including multiple effect sizes from each study. By a systematic literate search, 70 eligible studies were found that provided 390 effect sizes from 75 independent samples. The results showed a small positive correlation between parent–child relationship quality and empathy, and a small-to-moderate positive correlation between peer relationship quality and empathy, which was significantly stronger than the correlation with parent–child relationship quality. Hence, the meta-analytic results indicate that adolescents with higher quality relationships, especially with peers, indeed tend to show more concern for and understanding of others’ emotions than adolescents with lower quality relationships. Moreover, the moderation analyses showed stronger correlations for the positive dimension of relationship quality than for the negative dimension, and stronger correlations for composite scores of affective and cognitive empathy than for separate scores of the empathy dimensions. However, no differences in correlations were found between the affective and cognitive empathy dimension, and no moderation effects were found for gender and age. Thus, this meta-analysis demonstrates robust positive associations between parent–child and peer relationship quality and empathy in adolescence, implying that good empathic abilities may be a protective factor for experiencing poor relationships.

  相似文献   
48.
In response to ongoing plant genetic enclosures, the Open Source Seed Initiative (OSSI) is creating a ‘protected commons’ for seed. It is a project, I argue, that reflects characteristics of a growing transnational commoning movement. From the Zapatistas to seed wars, such movements draw attention to commons not simply as a resource, but as a dynamic and evolving social activity: commoning. In the US, OSSI includes 38 plant breeders, 48 seed companies and 377 crop varieties. Yet challenges remain for OSSI to gain wider legitimacy for ‘freed seed’, to build trust in a moral pledge, and to establish fair guidelines for which people and which seed can participate in making the commons. Using the metaphor of ‘beating the bounds’ – a feudal practice of contesting enclosures – I ask how OSSI defends the commons in intersecting arenas. The first way is legal, as OSSI negotiates a move from contract law toward moral economy law. Next is epistemic, as an informal breeder network revitalizes farmer knowledge, while proving more structurally able and culturally equipped to lead commoning efforts. Finally, I reflect on the nature of boundary beating itself, aided by Global South movements. Seed sovereignty perspectives suggest room for a pluriverse of commons to grow.  相似文献   
49.
50.
Using panel data and matching techniques, we exploit a rare change in communication flows—the endorsement switch to the Labour Party by several prominent British newspapers before the 1997 United Kingdom general election—to study the persuasive power of the news media. These unusual endorsement switches provide an opportunity to test for news media persuasion while avoiding methodological pitfalls that have plagued previous studies. By comparing readers of newspapers that switched endorsements to similar individuals who did not read these newspapers, we estimate that these papers persuaded a considerable share of their readers to vote for Labour. Depending on the statistical approach, the point estimates vary from about 10% to as high as 25% of readers. These findings provide rare evidence that the news media exert a powerful influence on mass political behavior.  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