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   17318篇
  免费   504篇
各国政治   726篇
工人农民   686篇
世界政治   1477篇
外交国际关系   602篇
法律   10351篇
中国共产党   2篇
中国政治   77篇
政治理论   3721篇
综合类   180篇
  2020年   211篇
  2019年   251篇
  2018年   333篇
  2017年   397篇
  2016年   422篇
  2015年   294篇
  2014年   343篇
  2013年   1718篇
  2012年   409篇
  2011年   440篇
  2010年   351篇
  2009年   384篇
  2008年   448篇
  2007年   469篇
  2006年   445篇
  2005年   398篇
  2004年   398篇
  2003年   422篇
  2002年   379篇
  2001年   684篇
  2000年   624篇
  1999年   509篇
  1998年   287篇
  1997年   247篇
  1996年   208篇
  1995年   210篇
  1994年   251篇
  1993年   222篇
  1992年   337篇
  1991年   375篇
  1990年   333篇
  1989年   348篇
  1988年   317篇
  1987年   334篇
  1986年   340篇
  1985年   334篇
  1984年   287篇
  1983年   318篇
  1982年   260篇
  1981年   240篇
  1980年   183篇
  1979年   251篇
  1978年   169篇
  1977年   146篇
  1976年   134篇
  1975年   123篇
  1974年   139篇
  1973年   120篇
  1972年   114篇
  1971年   94篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
961.
The level of degradation of DNA as a means for determining the time of death has been proposed as a valid adjunct to the classic thanatochronologic methods. The twofold aim of this work was to determine which organ might reveal both a correlation between the percentage of degradation of the DNA and the time lapse since death, and would be easiest to sample and yield the most reproducible results even in technically unfavorable situations such as on-the-spot investigations at the scene of death. A comparison of the spleen, blood, and liver showed that hepatic tissue best meets these specific needs because it shows a virtually linear correlation between the time elapsed since death and the level of degradation of the DNA, and it can easily be sampled at the scene of death by use of a common biopsy needle.  相似文献   
962.
Childhood sporting deaths   总被引:1,自引:0,他引:1  
  相似文献   
963.
Personal identification based on radiographic vertebral features   总被引:4,自引:0,他引:4  
Personal identification of human remains constitutes about 10% of the normal caseload of any forensic medicine practice. Identification can be achieved by a variety of methods, one of which is the comparison of antemortem and postmortem radiographs. There are numerous accounts of cranial and dental radiographic features useful for identification, whereas the availability of postcranial radiographs and especially plates that depict the vertebral column is less widespread among the forensic community. The authors here review the various vertebral features instrumental in positive identification that can be identified on radiographs of the spine.  相似文献   
964.
965.
Death resulting from ruptured cerebral artery aneurysm: 219 cases   总被引:1,自引:0,他引:1  
To characterize the demographics of ruptured cerebral artery aneurysm as a cause of death and to examine the effect of improved diagnostic and therapeutic techniques on the incidence of sudden death associated with the condition, the authors reviewed 219 autopsies performed at the Dallas County Medical Examiner's Office between 1977 and 1997 in which the cause of death was ruptured cerebral artery aneurysm. Ruptured cerebral artery aneurysms accounted for 1.5% of 15,033 natural deaths and 0.4% of all deaths (45,492) followed by autopsy during this period. The majority (56%) of cases occurred in females, with Caucasian females composing the largest group (38%). Seventy-seven percent of cases occurred in individuals between the ages of 31 and 70 years, with the highest concentration in the 41- to 50-year decade (29%). The most common location for ruptured aneurysms was the middle cerebral artery distribution (39%). Multiple aneurysms occurred in 22 (9.1%) cases. Other factors, such as medical history, coexisting disease, symptoms, activity at onset of symptoms, survival time, and toxicology results are also presented. Compared with literature reports before 1980, when ruptured cerebral artery aneurysms were reported as the cause of death in approximately 4% to 5% of sudden natural deaths, the results of this study suggest that despite improved diagnostic and therapeutic techniques during the past two decades, morbidity and mortality from ruptured aneurysms remain a significant health problem.  相似文献   
966.
Neeleman J 《危机》2002,23(3):114-120
The effect of exposure to risk factors for suicidal behavior varies from place to place and from period to period. This may be due to contextual influences, which arise if individuals' suicide risk depends not only on their personal exposure to risk or protective factors, but also on how these are distributed in their social, cultural, economic, or even physical environments. There has been relatively little explicit attention in suicide research for such contextual influences even though they are an important component of the cross-level bias, which can arise when aggregate level associations are assumed to also apply in individuals and vice versa. Contextual effects are conceptually related to the issues of social selection vs. causation, population density, and network effects. Because of a lack of prospective multilevel research, it is unclear exactly which mechanisms underlie the phenomenon that the distribution of risk factors in an individual's context may affect their suicide risk above and beyond their personal exposure. A number of mechanisms, like deviancy amplification, formalization of restraints, and buffering effects of social support are proposed. Contextual effects may result in a concentration of suicide risk in persons when the risk factors they are exposed to become rare--whether spontaneously or through focused prevention. This has important but mostly overlooked implications for population-based prevention strategies.  相似文献   
967.
The authors report on the case of a 18-year-old student who died suddenly and unexpectedly of a pericardial tamponade after perforated ulcer-polypous endocarditis of the aortic valve. The detection of aerococcus urinae--which usually causes urinary tract infection--on the inflamed aortic valve demonstrates an unusual pathogenetic chain linking complexes of findings in the urogenital system and the heart.  相似文献   
968.
969.
Tumescent liposuction is a common cosmetic procedure that is performed as an outpatient service in physician's offices and is largely believed to be safe. The protuberant areas of the body containing the undesirable fat deposits are injected with normal saline containing lidocaine and epinephrine for pain control and hemostasis, and the waterlogged cells are suctioned out via cannula through a small incision. We recently encountered three cases in which deaths were attributed to this procedure. Two showed fat embolization in the lung and one died from fluid overload. The osmium tetroxide post-fixed lung sections showed fat emboli in the interstitial capillaries and arterioles. We reviewed the recent literature and found that pulmonary thromboemboli, fat embolization, fluid overload, and lidocaine and epinephrine intoxication are found at autopsy in many cases. Forensic pathologists responsible for determining the cause and manner of death should become familiar with the postmortem findings and risks of liposuction therapy and communicate them to their clinical colleagues and communities.  相似文献   
970.
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