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   10938篇
  免费   354篇
各国政治   361篇
工人农民   535篇
世界政治   676篇
外交国际关系   358篇
法律   6858篇
中国共产党   35篇
中国政治   133篇
政治理论   2179篇
综合类   157篇
  2021年   71篇
  2020年   163篇
  2019年   145篇
  2018年   219篇
  2017年   260篇
  2016年   299篇
  2015年   245篇
  2014年   237篇
  2013年   968篇
  2012年   254篇
  2011年   295篇
  2010年   229篇
  2009年   298篇
  2008年   365篇
  2007年   372篇
  2006年   345篇
  2005年   323篇
  2004年   317篇
  2003年   265篇
  2002年   261篇
  2001年   379篇
  2000年   340篇
  1999年   273篇
  1998年   173篇
  1997年   125篇
  1996年   150篇
  1995年   126篇
  1994年   140篇
  1993年   134篇
  1992年   209篇
  1991年   260篇
  1990年   217篇
  1989年   218篇
  1988年   233篇
  1987年   209篇
  1986年   233篇
  1985年   200篇
  1984年   172篇
  1983年   164篇
  1982年   107篇
  1981年   132篇
  1980年   114篇
  1979年   109篇
  1978年   95篇
  1977年   82篇
  1976年   68篇
  1975年   66篇
  1974年   69篇
  1973年   79篇
  1971年   53篇
排序方式: 共有10000条查询结果,搜索用时 593 毫秒
191.
More than 80 million African children lack access to healthy shelter, and 16 million of these children are living on the streets. This phenomenon of street children represents massive social failure as well as a violation of the United Nations Convention on the Rights of the Child. Urbanization--and the attendant processes of industrial expansion, land speculation, and "beautification"--has created a cycle of poverty, evictions, family disruption, and unwanted and abandoned children. In African cities, at least 60% of the population lives in informal, underserviced, and frequently illegal slums and squatter settlements in households generally headed by a single mother. Increasingly, eviction is being used as a strategy for driving the poor out of urban areas where they have come to seek work. Mothers who are themselves illiterate, malnourished, and constantly facing the threat of eviction are unable to meet their children's basic security needs. Moreover, violent evictions subvert children's educational and health status, cause psychological trauma and the loss of a sense of belonging, and exacerbate the household's precarious economic status. Nongovernmental organizations (NGOs) have been successful in preventing some evictions and have established programs for the care of street children. Recommended is improved coordination between NGOs and local and national governments, as exemplified by the urban child welfare task force established by the Kenyan Government. Above all, however, NGOs need to develop strategies for dealing more effectively with mass urban poverty and providing the necessary infrastructure to improve the lives of slum residents.  相似文献   
192.
193.
194.
195.
196.
In Hannover/Germany in 1976 a so called "Society for Regenerative Hyperbaric Therapy" (Gesellschaft für Regenerative Uberdruck-Therapie) subjected 20 patients within two coupled multi-place chambers to a simulated hyperbaric environment, equivalent to a maximum of 4 ata, followed usually by gradual reductions of the pressure. The patients were of an average age of 67.2 years and were afflicted by various disorders. During one of the "dives" a patient developed air embolism of the central nervous system. During ensuing confusion of the chamber was opened suddenly, with resultant explosive reduction of the high pressure. This resulted in five letal accidents of decompression sickness. Post mortem examination revealed diffuse distribution of gas bubbles throughout the entire body. By elecronmicroscopy each bubble was covered by an osmiophilic coat. Post mortem findings are discussed and correlated with well-known and new clinical symptomes. These observations present for the first time fatal accidents of decompression sickness in humans, associated with hyperbaric air-therapy.  相似文献   
197.
The authors compared the effects of alcoholic drinks rich in fusel oil with the effects of diluted pure alcohol of the same quantity on 19 clinically healthy university students. The investigations utilized EEG and physiopsychic testing methods. The clinical symptoms were observed both under the effect of drinks and in a crapulous state ("hang-over"). It was found that alcoholic drinks rich in fusel oil can produce a more deviating EEG curve, an increased worsening of physiopsychic performance and of clinical and subjective symptoms. The necessity of regular quality control of alcoholic beverages is pointed out.  相似文献   
198.
199.
200.
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