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   575篇
  免费   33篇
各国政治   39篇
工人农民   96篇
世界政治   50篇
外交国际关系   24篇
法律   253篇
中国政治   13篇
政治理论   128篇
综合类   5篇
  2024年   2篇
  2023年   5篇
  2021年   6篇
  2020年   12篇
  2019年   19篇
  2018年   25篇
  2017年   32篇
  2016年   30篇
  2015年   32篇
  2014年   15篇
  2013年   93篇
  2012年   23篇
  2011年   22篇
  2010年   17篇
  2009年   13篇
  2008年   19篇
  2007年   25篇
  2006年   24篇
  2005年   13篇
  2004年   13篇
  2003年   14篇
  2002年   7篇
  2001年   11篇
  2000年   11篇
  1999年   10篇
  1998年   6篇
  1997年   7篇
  1996年   3篇
  1995年   9篇
  1994年   3篇
  1993年   7篇
  1992年   3篇
  1991年   5篇
  1990年   8篇
  1989年   6篇
  1988年   6篇
  1987年   6篇
  1986年   3篇
  1985年   6篇
  1984年   5篇
  1983年   6篇
  1982年   4篇
  1980年   5篇
  1979年   3篇
  1978年   2篇
  1977年   4篇
  1973年   3篇
  1972年   1篇
  1968年   1篇
  1966年   1篇
排序方式: 共有608条查询结果,搜索用时 625 毫秒
41.
42.
43.
A retrospective analysis of 68 cases of fatal childhood pedestrian accidents in South Australia that occurred over a 20-year period from January 1977 to December 1996 was undertaken. The age range was 12 months to 16 years (average, 7.6 years), with a male to female ratio of 41:27. The most common site of significant injury was the head (91.2%), followed by the abdomen (50%), chest (47.1%), and neck (38.2%). The most frequently encountered significant injury combinations involved the head, chest, and abdomen (14.7%); the head and chest (11.8%); and the head, neck, and abdomen (11.8%). Injuries were severe, consisting of extensive compound and comminuted skull fractures, neck fractures, and massive intraparenchymal brain and internal organ damage with avulsions and fragmentation. Non-life-threatening limb injuries occurred in 88% of cases. A distinct subgroup involved infants and younger children playing in driveways at home who were hit by reversing vehicles. The injuries were often of such a severe nature that death was instantaneous and with no possibility of successful medical intervention. More deaths occurred during the winter than summer months.  相似文献   
44.
45.
Efficient capillary electrophoretic STR analysis requires rapid, reproducible and robust separation of DNA fragments with reasonable capillary longevity--this is currently accomplished using proprietary commercial polymeric sieving matrices specifically developed for this separation. These matrices, while effective, are costly and do not provide adequate resolution of STR DNA fragments in capillaries with shorter effective separation lengths, increasing the time required to accomplish the separation and minimizing the potential extrapolation to other miniaturized platforms. As the forensic community looks toward next generation microchip technology as a means of processing casework more rapidly, new sieving polymers need to be evaluated for utilization in this platform. The research presented here describes the assessment of commercially-available polymeric sieving matrices for STR analysis, with consideration given to feasibility of incorporation into a microdevice. Polymer composition, molecular weight, and concentration were evaluated, along with an assessment of the effects of buffer composition, separation temperature, and capillary length. These variables were evaluated individually or collectively on the ability to resolve STR DNA fragments and the reproducibility of the separations and the results compared to a proprietary commercial product. A 600,000 Da MW poly(ethylene oxide) (PEO) solution at a 3% (w/v) concentration was determined to be the most suitable matrix for these separations. This polymer, in coated capillaries, provided highly robust and reproducible separations, with near baseline resolution of fragments having single base differences. Reductions in the temperature of the separation, from 60 degrees C to 40 degrees C, and the urea concentration of the buffer, from 7 M to 3.5 M, provided increased longevity of the PEO polymer for repeated separations. Comparison of this polymer with currently specified commercial products used for STR analysis showed that the optimized PEO matrix provided superior separations under all conditions tested. In addition, PEO could be utilized in shorter capillary systems, with a concurrent decrease in analysis time, highlighting its potential for use in shortened capillary or microdevice systems.  相似文献   
46.
47.
48.
In a strict and conservative society like Malaysia, the number of cases of infanticide has continued to occur. The authors present two typical cases of infanticide in Malaysia. Case 1 concerned a body of a fully mature newborn fetus disposed in a rubbish bin. The head was traumatically amputated by the rubbish truck's compactor. The umbilical cord was still attached to the body, with no reddening around the insertion. The severed neck showed features consistent with post-mortem amputation. The significant finding was expanded crepitant lungs, which floated in water. The histology of the lungs showed expanded alveoli. It was concluded that the baby had been born alive, but no cause of death could be elicited. Case 2 concerned a decomposed mature newborn found in a scrub forest. The internal organs showed advanced putrefaction, the lungs being collapsed, congested, and hemorrhagic, typical of decomposed lungs. No conclusion could be made about the state of birth or the cause of death because of the putrefied state of the body. The two cases illustrate the typical cases and problems faced by pathologists locally and probably elsewhere in the world. Most of the bodies are found in a putrefied state. Pathologists have to ascertain not only maturity and live birth but also the cause of death, which may be very subtle or masked by putrefaction. The problems of diagnosis of live birth are discussed.  相似文献   
49.
50.
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