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   24727篇
  免费   593篇
  国内免费   5篇
各国政治   897篇
工人农民   1686篇
世界政治   1399篇
外交国际关系   890篇
法律   15146篇
中国共产党   6篇
中国政治   159篇
政治理论   4967篇
综合类   175篇
  2020年   228篇
  2019年   287篇
  2018年   1546篇
  2017年   1528篇
  2016年   1371篇
  2015年   367篇
  2014年   334篇
  2013年   1623篇
  2012年   643篇
  2011年   1361篇
  2010年   1336篇
  2009年   961篇
  2008年   1211篇
  2007年   1199篇
  2006年   545篇
  2005年   565篇
  2004年   653篇
  2003年   656篇
  2002年   476篇
  2001年   678篇
  2000年   556篇
  1999年   498篇
  1998年   262篇
  1997年   184篇
  1996年   224篇
  1995年   205篇
  1994年   230篇
  1993年   205篇
  1992年   330篇
  1991年   366篇
  1990年   344篇
  1989年   288篇
  1988年   325篇
  1987年   275篇
  1986年   322篇
  1985年   289篇
  1984年   243篇
  1983年   232篇
  1982年   185篇
  1981年   197篇
  1980年   132篇
  1979年   180篇
  1978年   132篇
  1977年   121篇
  1976年   99篇
  1975年   125篇
  1974年   132篇
  1973年   104篇
  1972年   101篇
  1969年   98篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
281.
The case of the death by arsenic poisoning of a 62-year-old white man is presented. One year prior to death, he developed intermittent bouts of severe gastroenteritis with vomiting and diarrhea, hyperpigmentation and keratosis of the skin, neutropenia, and Guillain-Barré-like neuropathy for which he was hospitalized several times. Urine test results 6 months prior to death indicating 36 mg/L arsenic were believed to be in error. At the patient's last admission, he appeared in the emergency room with severe gastroenteritis, hypotension, and dehydration. He died 3 days later. Antemortem as well as autopsy specimens revealed elevated arsenic concentrations. Arsenic micrograms/g analysis by neutron activation of hair pulled from the man's head revealed by centimeter segmental analysis proximal to distal: 226, 104, 28, 56, 41, 40, and 74. The wife of the decedent was charged with murder by arsenic poisoning of this, her fifth, husband. The defense alleged that the decedent had committed suicide. The judge awarded a directed verdict of "not guilty." Particulars of the medical, toxicological, and investigative findings are presented.  相似文献   
282.
283.
284.
In the summer of 1984, police in Pinellas County, Florida, confiscated six identically colored imported Asian skulls (in a shipping case) from a private citizen. In May 1988, in nearby Hillsborough County, police confiscated a very similar skull from another private citizen, who allegedly had found it in an abandoned house. Aside from slight color differences between the six found in Pinellas County and the one found in Hillsborough County, the skulls are virtually identical in their osteological characteristics and condition and in the vital statistics derived from each. Each skull is as clean and dry as those typically sold by commercial scientific supply outlets in the United States. Each is edentulous (primarily premortem), between approximately 20 and 60 years of age at death, and morphologically Asian. Five of the seven are morphologically male, one is morphologically female, and one is a mosaic with respect to gender-related features. Police, medical examiners, coroners, and forensic anthropologists should be aware of such "souvenir" specimens, in the event that they encounter similar skulls. Discriminant function analyses for race and sex yield considerably conflicting results, which underscores the need for using extreme caution when interpreting forensic science estimates based on such techniques.  相似文献   
285.
The authors developed a method of malathion insecticide determination in the cadaveric material (blood and wall of the stomach) including extraction of 5 ml of blood (5 g of fragmented tissue of stomach wall) by hexan; preparative chromatographic purification of extract on silicagel layer L 5/40 mkm in hexan-diethyl ether system 10:2; Gas-liquid chromatographic investigation on column with 5% SE-30 and 5% XE-60 (Chromatograph "Colour-106" with thermionic detector). This method makes it possible to detect 72-76% of malathion added.  相似文献   
286.
287.
288.
This paper examines the process by which R&D results funded by the Office of Conservation and Renewable Energy (CE) of the US Department of Energy (DOE) have generated commercial applications. It looks at examples of technology-transfer procedures and activitees across three of CE's component offices that correspond to the major energy end-use sectors: transportation, buildings, and industry. On the surface, the conservation programs would appear to have little strategic consistency and, therefore, lack the clear leadership many seek in a technology-transfer program. However, as an alternative to strategic consistency, one may tailor the technology-transfer approach of each program to its unique circumstances. This paper presents case studies of such tailoring, in which the diversity of approaches mirrors the complexity of the energy end-use markets and the private-public interests that must be negotiated to successfully commercialize energy-saving innovations. The paper discusses the lessons learned about the conditions requiring adaptive design and the structures and practices that have been proven effective.  相似文献   
289.
290.
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