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   4673篇
  免费   156篇
各国政治   404篇
工人农民   134篇
世界政治   459篇
外交国际关系   359篇
法律   1938篇
中国共产党   1篇
中国政治   34篇
政治理论   1451篇
综合类   49篇
  2023年   29篇
  2022年   38篇
  2021年   49篇
  2020年   96篇
  2019年   109篇
  2018年   149篇
  2017年   177篇
  2016年   188篇
  2015年   114篇
  2014年   149篇
  2013年   772篇
  2012年   143篇
  2011年   143篇
  2010年   127篇
  2009年   163篇
  2008年   197篇
  2007年   196篇
  2006年   145篇
  2005年   164篇
  2004年   139篇
  2003年   121篇
  2002年   134篇
  2001年   90篇
  2000年   84篇
  1999年   92篇
  1998年   74篇
  1997年   64篇
  1996年   53篇
  1995年   70篇
  1994年   56篇
  1993年   48篇
  1992年   49篇
  1991年   57篇
  1990年   32篇
  1989年   54篇
  1988年   41篇
  1987年   42篇
  1986年   55篇
  1985年   21篇
  1984年   28篇
  1983年   37篇
  1982年   35篇
  1981年   22篇
  1980年   31篇
  1979年   17篇
  1978年   22篇
  1977年   17篇
  1976年   17篇
  1975年   10篇
  1974年   21篇
排序方式: 共有4829条查询结果,搜索用时 8 毫秒
141.
Agroecology has played a key role in helping Cuba survive the crisis caused by the collapse of the socialist bloc in Europe and the tightening of the US trade embargo. Cuban peasants have been able to boost food production without scarce and expensive imported agricultural chemicals by first substituting more ecological inputs for the no longer available imports, and then by making a transition to more agroecologically integrated and diverse farming systems. This was possible not so much because appropriate alternatives were made available, but rather because of the Campesino-a-Campesino (CAC) social process methodology that the National Association of Small Farmers (ANAP) used to build a grassroots agroecology movement. This paper was produced in a ‘self-study’ process spearheaded by ANAP and La Via Campesina, the international agrarian movement of which ANAP is a member. In it we document and analyze the history of the Campesino-to-Campesino Agroecology Movement (MACAC), and the significantly increased contribution of peasants to national food production in Cuba that was brought about, at least in part, due to this movement. Our key findings are (i) the spread of agroecology was rapid and successful largely due to the social process methodology and social movement dynamics, (ii) farming practices evolved over time and contributed to significantly increased relative and absolute production by the peasant sector, and (iii) those practices resulted in additional benefits including resilience to climate change.  相似文献   
142.
143.
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   
144.
The purpose of this article is to explain how public managers can influence the mix of institutional logics in a process of organizational change. To do this, the concept of post-transformational leadership is related to institutional logics. The article is based on a case study of the Danish Crime Prevention Council. The study shows how post-transformative leaders are urged to move from strategies of collaboration to strategies of manipulation, hypocrisy, and the hijacking of institutional logics.  相似文献   
145.
There is limited research that has examined experimentally the effects of muscular images on adolescent boys’ body image, with no research specifically examining the effects of music television. The aim of the current study was to examine the effects of viewing muscular and attractive singers in music video clips on early, mid, and late adolescent boys’ body image, mood, and schema activation. Participants were 180 boys in grade 7 (mean age = 12.73 years), grade 9 (mean age = 14.40 years) or grade 11 (mean age = 16.15 years) who completed pre- and post-test measures of mood and body satisfaction after viewing music videos containing male singers of muscular or average appearance. They also completed measures of schema activation and social comparison after viewing the clips. The results showed that the boys who viewed the muscular clips reported poorer upper body satisfaction, lower appearance satisfaction, lower happiness, and more depressive feelings compared to boys who viewed the clips depicting singers of average appearance. There was no evidence of increased appearance schema activation but the boys who viewed the muscular clips did report higher levels of social comparison to the singers. The results suggest that music video clips are a powerful form of media in conveying information about the male ideal body shape and that negative effects are found in boys as young as 12 years.  相似文献   
146.
147.
148.
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   
149.
Sharp force trauma is a common homicide method. The weapon is typically a knife, which is easily accessible and does not require special skills. We have analyzed all 471 sharp force homicides in Denmark during 1992–2016 with special focus on aspects that are relevant to forensic pathologists, including the distribution of wounds and organ injuries. Most homicides were committed inside with a kitchen knife. The front left thorax was the most common area to be affected by sharp force trauma. In 18.9% of the victims, there was only one sharp injury, the majority on the thorax. The most common trajectory for stab wounds was directly posterior with no deviation to the sides or up/down followed by directly anterior. The heart (including pericardium) and lungs (including hemo- and pneumothorax) had injuries in more than 75% of the victims. 67% of victims were males. Female victims had more sharp force injuries and defense wounds than male victims. Most females were killed in domestic homicides (73.7%), most commonly in partner killings (56.4%). In contrast, many male victims were killed in a setting of nightlife/intoxication (34.0%) most by a friend/acquaintance delivering a few stab wounds. The results clearly show strong sex differences in both victims and offenders. This could be useful for shaping policies and public opinion, and as a route for understanding the developments in interpersonal violence. In the narrow setting of death investigation, our results will provide an evidence-based approach to understanding the injury patterns in sharp force homicide.  相似文献   
150.
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   
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