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   16414篇
  免费   525篇
  国内免费   5篇
各国政治   663篇
工人农民   737篇
世界政治   1084篇
外交国际关系   542篇
法律   10570篇
中国共产党   6篇
中国政治   154篇
政治理论   3016篇
综合类   172篇
  2020年   221篇
  2019年   270篇
  2018年   333篇
  2017年   391篇
  2016年   402篇
  2015年   293篇
  2014年   310篇
  2013年   1490篇
  2012年   446篇
  2011年   478篇
  2010年   395篇
  2009年   410篇
  2008年   495篇
  2007年   537篇
  2006年   514篇
  2005年   469篇
  2004年   456篇
  2003年   486篇
  2002年   423篇
  2001年   664篇
  2000年   540篇
  1999年   477篇
  1998年   243篇
  1997年   168篇
  1996年   202篇
  1995年   171篇
  1994年   196篇
  1993年   195篇
  1992年   323篇
  1991年   353篇
  1990年   338篇
  1989年   281篇
  1988年   321篇
  1987年   275篇
  1986年   322篇
  1985年   284篇
  1984年   230篇
  1983年   227篇
  1982年   178篇
  1981年   191篇
  1980年   128篇
  1979年   172篇
  1978年   122篇
  1977年   108篇
  1976年   97篇
  1975年   123篇
  1974年   132篇
  1973年   104篇
  1972年   100篇
  1969年   98篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
921.
Traditionally, toolmark test exemplars are produced by applying a tool's working surface to a piece of soft metal such as lead. Soft, pliable metals are primarily used for this purpose because they will replicate the microscopic grooves present on a tool's working surface without damaging the tool. In this paper the authors present an alternative material for the preparation of test toolmarks. Jewelry modeling or carving waxes are utilized in this study. These waxes are designed for the jewelry modeling industry to create very fine, highly detailed wax models of jewelry pieces that will be cast in various metals utilizing the lost wax casting method. Jeweler's waxes have been found to be ideal for preparing test toolmarks from exemplar tools. The test tool's working surface is applied to a piece of the appropriate wax in a manner consistent with the tool's design. The replicas obtained are exact, highly detailed, 1:1, negative impressions of the exemplar tools working surface, have a long shelf-life, and are suitable for use in toolmark examination and comparison cases.  相似文献   
922.
A method was suggested for identifying reladorm and donormil in pharmaceutical drugs and biological objects. The above substances are isolated by 96% ethanol or by mixture of chloroform and isopropanol. 7 color reactions, 3 microcrystalloscopic reactions and chromatography in thin sorbent layer are suggested for identification.  相似文献   
923.
Posttraumatic alterations in the cervical spine ligaments were studied clinically and psychologically in the victims with mechanical injuries of the musculoligamentous system of the cervical spine. A clinical course of the traumatic process and biomechanical musculoligamentous alterations, development and severity of mental disorders were established. These characteristics should be taken into consideration in forensic medical evaluation of health deterioration.  相似文献   
924.
925.
A complex investigation of catalase activity in erythrocytes was conducted basing on the results of computer quantitative morphometry of histochemical examination of blood samples from persons with mild craniocerebral trauma. It was found that erythrocytic catalase activity correlates with severity of brain trauma. A novel technique of objective histochemical diagnosis of trauma is described. It provides objective grounds for expert conclusions. Differential features of erythrocytic shape were defined in a small series of micropreparations vs the rest blood samples.  相似文献   
926.
Nitrates and nitrites, accumulating in toxic concentrations in soil, plants, water and foodstuffs, can cause lethal intoxication. The method of isolation, identification and quantitation has been elaborated for their diagnosis. It is based on the isolation of water and subsequent chromogenic test plus photoelectrocolorimetry.  相似文献   
927.
928.
929.
A multimodality dental examination was made and anatomomorphological features of teeth and tooth sequences were studied in 200 policemen using clinical examination, morphological investigation of plaster jaw models, analysis of x-rays and statistics, intraoral videocamera pictures, computer processing. The scheme of creation of dental data bank applicable in personal identification is offered.  相似文献   
930.
Some causes of ineffective dental care because of the patient's negligence were analyzed. In 16 cases the patients ignored recommendations of the dentist and missed visits to the doctor. As a result, the patients developed complications leading to esthetic dissatisfaction, prolonged treatment, repeated prosthetic management.  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