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   31507篇
  免费   1551篇
各国政治   1328篇
工人农民   1337篇
世界政治   2398篇
外交国际关系   1068篇
法律   20173篇
中国共产党   3篇
中国政治   167篇
政治理论   6332篇
综合类   252篇
  2021年   161篇
  2020年   583篇
  2019年   640篇
  2018年   830篇
  2017年   882篇
  2016年   984篇
  2015年   706篇
  2014年   805篇
  2013年   3256篇
  2012年   806篇
  2011年   849篇
  2010年   806篇
  2009年   854篇
  2008年   861篇
  2007年   879篇
  2006年   873篇
  2005年   759篇
  2004年   778篇
  2003年   698篇
  2002年   717篇
  2001年   1174篇
  2000年   1084篇
  1999年   875篇
  1998年   486篇
  1997年   384篇
  1996年   368篇
  1995年   373篇
  1994年   398篇
  1993年   368篇
  1992年   563篇
  1991年   600篇
  1990年   571篇
  1989年   563篇
  1988年   554篇
  1987年   548篇
  1986年   586篇
  1985年   581篇
  1984年   496篇
  1983年   474篇
  1982年   394篇
  1981年   366篇
  1980年   302篇
  1979年   426篇
  1978年   259篇
  1977年   219篇
  1976年   194篇
  1975年   205篇
  1974年   239篇
  1973年   183篇
  1972年   183篇
排序方式: 共有10000条查询结果,搜索用时 109 毫秒
151.
Dilutions of 100 serum samples of various GM phenotypes were dotted onto a nitrocellulose membrane. The serum dot-blots were detected with peroxidase-labeled anti-G3M T monoclonal antibody (anti-G3M T MAb). Up to a 1 : 256 dilution could be G3M T-typed correctly. By use of anti-G3M T MAb and peroxidase-labeled anti-mouse IgG or the biotin-avidin system instead of use of labeled anti-G3M T MAb, up to a 1 : 512 or 1 : 1024, respectively, dilution was typable. As with previous work with G3M G MAb, the dot immunobinding (DIB) method for G3M T typing was found very simple and practical.  相似文献   
152.
The impact of research information depends on its ability to change beliefs or policy assumptions within the relevant audiences. As a hybrid of American and British systems, Canada's chosen decision-making structure for policy-making and its legislative framework for health insurance make these audiences unclear and not readily accessible. This factor and historical characteristics of the research community which made them only partially responsive to the values of decisionmakers provide an explanation for the limited past use of research information in Canadian health policy. More recently, improved responsiveness by researchers and an emerging definition of the audiences by legislative policymakers are bringing about a gradual increase in the potential impact of research at the levels of administrative and clinical policy. Because of continuing decision-making constraints on legislative policy, however, impact at this level is predicted to remain diffuse, with only cautious acceptance of the changes in beliefs implied by research.  相似文献   
153.
A technique was developed for Gm/Km typing of bloodstains and sera in U-bottom microtiter plates. Gm/Km typing of sweat and urine samples was also attempted with limited success.  相似文献   
154.
155.
156.
157.
HIV infection is now perceived as the end stage of a chronic disease that is spreading most rapidly among blacks and Hispanics. The politics of the HIV epidemic in the 1980s were dominated by four interacting factors: fear and fascination; who had the disease and to whom it seemed to be spreading; the endemic problems of United States social policy; and the impact on policy of advances in scientific knowledge. This paper analyzes the political history of each of these factors and describes the dominant policies of the federal government and the states regarding HIV in the areas of surveillance, prevention, research, and financing. Four uncertainties will have a profound influence on the future politics of the HIV epidemic: how the states and the federal government will address the general problems of paying for the care of people with chronic diseases and providing access to care for the uninsured and the underinsured; the number and distribution of the sexual behaviors that transmit infection with HIV and the effectiveness of policies to persuade people to modify these behaviors; precisely who uses addictive drugs and the effectiveness of measures to change their behavior; and the natural history of the virus.  相似文献   
158.
China's experiments with democracy in this century were few in number, short in duration, and limited in their democratic characteristics. Democratic institutions malfunctioned in numerous ways. Nine sets of causes for the failure of Chinese democracy can be suggested: ideology, internal and external war, military intervention, Chinese political culture, underdevelopment, a peasant mass, flaws in the design of Chinese constitutions, moral failures by democratic politicians, or the lack of transactional benefits for military‐based elites in the process of democratic transition. Each of these factors is reviewed critically with an eye to its possible lessons.  相似文献   
159.
Postmortem changes in sulfide concentrations in body tissues were examined in autopsied rats exposed to hydrogen sulfide concentrations of 550 to 650 ppm, and in nonexposed rats and humans. Analyses were made by gas chromatography, following an extractive alkylation. Sulfide concentrations in the blood, liver, and kidneys of rats increased in both the exposed and nonexposed groups, depending on the lapse of time after death. On the other hand, the lung, brain, and muscle showed little or no change in sulfide concentration with elapse of time after death. The data obtained from human tissues were almost the same as those for rats, except data for blood, in which no or little increase of sulfide was observed.  相似文献   
160.
A 22-year-old Korean soldier, who had received blows to the neck and epigastrium from an officer 10 h earlier, suddenly died after massive hematemesis. He had been in relatively good health except for episodes of blood-tinged vomiting approximately 5 and 7 months prior to this event. Postmortem examination revealed angiodysplasia involving the gastroesophageal junction, and the stomach was distended with blood. No abnormal findings were present around the whole viscera, and the duodenum was free of blood. The pathologic significance of upper gastrointestinal angiodysplasia as a potential source of bleeding and a chronologic correlation between the trauma and bleeding are discussed.  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