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   19272篇
  免费   1245篇
各国政治   792篇
工人农民   876篇
世界政治   1268篇
外交国际关系   590篇
法律   13564篇
中国共产党   2篇
中国政治   123篇
政治理论   3197篇
综合类   105篇
  2021年   92篇
  2020年   448篇
  2019年   459篇
  2018年   577篇
  2017年   600篇
  2016年   687篇
  2015年   520篇
  2014年   564篇
  2013年   1933篇
  2012年   524篇
  2011年   555篇
  2010年   559篇
  2009年   584篇
  2008年   553篇
  2007年   548篇
  2006年   571篇
  2005年   488篇
  2004年   487篇
  2003年   410篇
  2002年   457篇
  2001年   772篇
  2000年   698篇
  1999年   532篇
  1998年   254篇
  1997年   189篇
  1996年   203篇
  1995年   204篇
  1994年   188篇
  1993年   193篇
  1992年   350篇
  1991年   359篇
  1990年   343篇
  1989年   337篇
  1988年   366篇
  1987年   310篇
  1986年   371篇
  1985年   360篇
  1984年   271篇
  1983年   255篇
  1982年   192篇
  1981年   183篇
  1980年   155篇
  1979年   240篇
  1978年   130篇
  1977年   113篇
  1976年   92篇
  1975年   121篇
  1974年   150篇
  1973年   104篇
  1972年   108篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
A 2-month-old infant girl died suddenly as a result of torsion of the uterine adnexa. The infant was found unresponsive in bed and was pronounced dead shortly after her arrival at a hospital. There were no antecedent signs of illness. At autopsy, the right ovary and right fallopian tube were twisted and were dark purple, swollen, and necrotic. The right ovary was enlarged by a follicle cyst 4 cm in diameter, which likely precipitated the torsion. The mechanism of death was unclear but may have resulted from the release of cytokines produced in response to necrotic adnexal tissue. Fatal uterine adnexal torsion has been reported rarely in infants; in all those cases there were antecedent symptoms. Torsion of the uterine adnexa should be included in the differential diagnosis of sudden death in infancy.  相似文献   
992.
Sudden death resulting from lesions of the cardiac conduction system   总被引:1,自引:0,他引:1  
Sudden unexpected deaths in young persons with noncontributory histories, autopsy results, and drug screen results are a common problem in forensic pathology. As part of the evaluation of such cases, the cardiac conduction system (CCS) should be studied. To determine the type and incidence of lethal CCS lesions, the authors reviewed their files of sudden unexpected cardiac deaths with particular attention to cases with causes of death in the conduction system. Cases of sudden cardiac death in patients aged < or=40 years during a 10-year period (Michigan) and a 4 year-period (Spain) were selected from the files. From this group, cases were identified in which the cause of death was a lethal change in the CCS. The portions of the heart containing the CCS were excised, and at least one hematoxylin and eosin slide and at least one trichrome or elastic trichrome slide per block were studied. In the two centers, 381 cases of sudden cardiac death were identified. The most common causes of sudden cardiac death were arteriosclerotic narrowing of the coronary arteries, cardiomyopathy, and myocarditis. In 82 cases, there was no identifiable cause of death even after complete gross and microscopic autopsy was performed, a medical history was obtained, and a drug screen was performed. In 11 cases, the CCS contained lesions that were considered lethal: narrowing of the atrioventricular node artery by fibromuscular hyperplasia (7 cases) and atrioventricular node tumors (4 cases). The 11 cases accounted for 2.9% of the 381 cases of sudden cardiac death and 11.8% of the indeterminable cases. It was concluded that examination of the CCS in deaths in which the gross and microscopic autopsy, history, and drug screen fail to provide a cause of death can yield a cause of death in a significant percentage of cases. If heart block was not documented during life and no explanatory lesions were found during routine cardiac examination, examination of the CCS can yield valuable information.  相似文献   
993.
994.
995.
This article addresses important developments in the field of medicine and law during the period of September 2000 through August 2001. It does not discuss every reported case or piece of legislation but surveys some of the more significant developments in the medicine and law arena.  相似文献   
996.
997.
The cause of drowning deaths in good swimmers may be difficult to solve. After homicide, suicide and other kinds of immersion deaths have been ruled out, not only alcohol and narcotics, but also other psychotropic substances such as thornapple and angel's trumpet should be taken into consideration--at least in adolescents and young adults. The article reports on an accidental death by drowning under the influence of tropane alkaloids after consumption of a decoction of the flowers of angel's trumpet.  相似文献   
998.
999.
Nuclear magnetic resonance (NMR) spectroscopy was employed for the purpose of identifying samples of materials suspected of containing sodium fluoroacetate (Compound 1080). Acquisition of routine proton (1H) and carbon (13C) NMR spectra provided a straight-forward means for determining the presence of Compound 1080 in the samples and thus afforded a simple method for analysis and identification of this compound.  相似文献   
1000.
Antitrust law represents the principal legal tool that the United States employs to police private markets, yet it often relegates quality and nonprice considerations to a secondary position. While antitrust law espouses the belief that vigorous competition will enhance quality as well as price, little evidence exists of the practical ability of courts to deliver on that promise. In this Article, Professors Hammer and Sage examine American health care as a vehicle for advancing understanding of the nexus among competition, quality, and antitrust law. The Article reports results of a comprehensive empirical review of judicial opinions in health care antitrust litigation between 1985 and 1999, with specific attention to courts' handling of quality and other nonprice concerns. Professors Hammer and Sage conclude that, although antitrust law cannot be expected to serve as the sole oversight mechanism for industries as complex and quality dependent as health care, courts have been successful incorporating some nonprice factors into antitrust analysis.  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