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   13202篇
  免费   441篇
各国政治   669篇
工人农民   571篇
世界政治   834篇
外交国际关系   391篇
法律   8260篇
中国共产党   4篇
中国政治   83篇
政治理论   2724篇
综合类   107篇
  2020年   165篇
  2019年   207篇
  2018年   287篇
  2017年   321篇
  2016年   313篇
  2015年   243篇
  2014年   238篇
  2013年   1423篇
  2012年   359篇
  2011年   338篇
  2010年   287篇
  2009年   308篇
  2008年   381篇
  2007年   351篇
  2006年   374篇
  2005年   337篇
  2004年   348篇
  2003年   310篇
  2002年   319篇
  2001年   430篇
  2000年   413篇
  1999年   309篇
  1998年   184篇
  1997年   171篇
  1996年   149篇
  1995年   152篇
  1994年   144篇
  1993年   159篇
  1992年   268篇
  1991年   277篇
  1990年   270篇
  1989年   260篇
  1988年   239篇
  1987年   255篇
  1986年   273篇
  1985年   264篇
  1984年   224篇
  1983年   238篇
  1982年   145篇
  1981年   137篇
  1980年   117篇
  1979年   150篇
  1978年   128篇
  1977年   105篇
  1976年   93篇
  1975年   104篇
  1974年   118篇
  1973年   115篇
  1972年   100篇
  1968年   80篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
971.
Ms. Whetsell examines the Bell Regulations, which limit New York's hospital residents' work hours and require increased supervision from senior doctors, in light of the currently pending federal bill that seeks to do the same. The article argues that the federal government should draw lessons from the New York experience before proceeding with similar guidelines. The article notes that many roadblocks have prevented successful implementation of the New York policy, including a long-standing tradition of "hazing" first-year residents with long, unsupervised hours; medical community resistance to the notion of residents' sleep deprivation and dislike of government interference; and a general fear within the medical community of increased medical malpractice liability and other indicia of "blame culture." The Article concludes that the most effective approach to patient safety related to residency sleep deprivation should work within hospital culture, not against it. The proposed alternative approach would encourage patient safety strategies that value teamwork and cross-discipline collaboration, and consequently result in greater satisfaction for residents, hospitals, and patients.  相似文献   
972.
973.
974.
Dickerson JF 《Time》2003,162(23):48-51
  相似文献   
975.
The fingernails of Mary Sullivan, the last victim of the Boston Strangler, were examined to determine if any genetic information about the murderer could be obtained. The nails were extremely friable necessitating the development of new techniques for isolating and purifying DNA. DNA yields from nails were optimized by using a NaOH-based preparation technique, which was simple, efficient, and minimized handling. Methods for selectively and thoroughly removing exogenous material on nails were also developed through use of a species-specific PCR assay, wherein mitochondrial DNA from the nail could easily be differentiated from DNA of contaminating cells.  相似文献   
976.
This work presents a novel collection method for gunshot residues (GSR) using a sampling procedure based on ethylenediaminetetraacetic acid (EDTA) solution as a complexing agent on moistened swabs. Detection was via a sector-field inductively coupled plasma mass spectrometry (HRICP-MS). The proposed collection and analytical method allowed detection of antimony (Sb), barium (Ba) and lead (Pb) after .38 shot tests. at detection limits of less than 1 microg L(-1) in four different areas of the hands of volunteers. This paper includes a discussion concerning hand areas near the thumb and forefinger as being more suitable for GSR collection as well as a comparison between differences observed using 2% diluted EDTA. 2% nitric acid solution, and simple deionized water as collecting solutions, proving the superior efficiency of EDTA in GSR recoveries.  相似文献   
977.
978.
Zaleplon, a sedative-hypnotic, was identified in the blood of a subject arrested for impaired driving. Symptoms reported were those of central nervous system (CNS) depression. The zaleplon concentration was determined to be 0.13 microg/mL. Symptoms included slow movements and reactions, poor coordination, and lack of balance. Although no quantitative relationship between blood concentrations and degree of driving impairment is currently possible, it is reasonable to conclude that because of its specific activity as a sedative-hypnotic, blood concentrations consistent with doses exceeding therapeutic concentrations of zaleplon have the potential to cause impairment of psychomotor function, and would impair a person's level of consciousness and driving ability.  相似文献   
979.
980.
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