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   508篇
  免费   23篇
各国政治   30篇
工人农民   23篇
世界政治   75篇
外交国际关系   36篇
法律   227篇
中国政治   3篇
政治理论   123篇
综合类   14篇
  2021年   3篇
  2020年   7篇
  2019年   19篇
  2018年   14篇
  2017年   13篇
  2016年   22篇
  2015年   12篇
  2014年   12篇
  2013年   103篇
  2012年   16篇
  2011年   12篇
  2010年   11篇
  2009年   12篇
  2008年   25篇
  2007年   14篇
  2006年   17篇
  2005年   9篇
  2004年   18篇
  2003年   15篇
  2002年   12篇
  2001年   9篇
  2000年   10篇
  1999年   4篇
  1998年   8篇
  1997年   10篇
  1996年   5篇
  1995年   7篇
  1994年   8篇
  1993年   9篇
  1992年   5篇
  1991年   5篇
  1990年   4篇
  1989年   5篇
  1988年   2篇
  1987年   7篇
  1986年   6篇
  1985年   5篇
  1984年   6篇
  1983年   5篇
  1982年   6篇
  1981年   6篇
  1980年   6篇
  1979年   2篇
  1978年   2篇
  1977年   4篇
  1976年   4篇
  1974年   2篇
  1973年   2篇
  1970年   2篇
  1968年   2篇
排序方式: 共有531条查询结果,搜索用时 15 毫秒
201.
An automated headspace gas chromatography method was developed for the determination of formate (formic acid) in postmortem specimens, based on the in situ sulfuric acid-methanol methylation of formic acid to methyl formate. Diisopropyl ether was used as an internal standard. The method was applied to over 150 postmortem cases where methanol was detected. Of the 153 cases presented, 107 deaths were attributed to acute methanol toxicity. In the vast majority of the remaining 46 deaths, the methanol was determined to be present as a postmortem or perimortem artifact, or was otherwise incidental to the cause of death. Of the 76 victims who were found dead and blood was collected by the medical examiner, all but one had a postmortem blood formate concentration greater than 0.50 g/L (mean 0.85 g/L; n = 74). The sole exception involved suicidal ingestion of methanol where the blood methanol concentration was 7.9 g/L (790 mg/100 mL) and blood formate 0.12 g/L. In 97% (72/74) of the cases where blood was available, the blood formate was between 0.60 and 1.40 g/L. In 31 of the 153 cases, the victim was hospitalized and blood obtained on admission or soon after was analyzed for methanol and formate during the subsequent death investigation; the vast majority (27/30) had antemortem blood formate concentrations greater than 0.50 g/L. Cases with samples taken prior to death with blood formate concentrations less than 0.5 g/L can readily be explained by active treatment such as dialysis. The blood formate method has also been useful in confirming probable perimortem or postmortem contamination of one of more fluids or tissues with methanol (e.g., windshield washer fluid or embalming fluid), where methanol ingestion was unlikely.  相似文献   
202.
The medical examiner community plays a key role in the organ and tissue procurement process for transplantation. Since many, if not most, potential organ or tissue donors fall under medicolegal jurisdiction, the medical examiner bears responsibility to authorize or deny the procurement of organs or tissues on a case-by-case basis. This responsibility engenders a basic dichotomy for the medical examiner's decision-making process. In cases falling under his/her jurisdiction, the medical examiner must balance the medicolegal responsibility centered on the decedent with the societal responsibility to respect the wishes of the decedent and/or next of kin to help living patients. Much has been written on this complex issue in both the forensic pathology and the transplantation literature. Several studies and surveys of medical examiner practices, as well as suggested protocols for handling certain types of cases, are available for reference when concerns arise that procurement may potentially hinder medicolegal death investigation. It is the position of the National Association of Medical Examiners (NAME) that the procurement of organs and/or tissues for transplantation can be accomplished in virtually all cases, without detriment to evidence collection, postmortem examination, determination of cause and manner of death, or the conducting of criminal or civil legal proceedings. The purpose of this position paper is to review the available data, the arguments for and against medical examiner release, and to encourage the release of organs and tissues in all but the rarest of circumstances.  相似文献   
203.
204.
205.
This article presents a national measure of Americans’ level of concern about economic inequality from 1966 to 2015, and analyzes the relationship between this construct and public support for government intervention in the economy. Current research argues that concerns about economic inequality are associated with a desire for increased government action, but this relationship has only been formally tested using cross-sectional analyses. I first use a form of dynamic factor analysis to develop a measure of national concern over time. Using an error correction model I then show that an increase in national concern about economic inequality does not lead to a subsequent increase in support for government intervention in the economy. Instead there is some evidence that, once confounding factors are accounted for, an increase in concern could lead to reduced support for government intervention.  相似文献   
206.
207.
208.
With the increasing availability of statistics describing the occupational structures of different industries manpower forecasters are beginning to develop more sophisticated models. The economic rationale of such models has tended to be obscured by the mathematics involved and an understandable eagerness to put the data to use in forecasting. In addition, the systematic testing of the explanatory power of these models has been neglected where it has not been hampered by the shortage of data series. The RAS model has featured prominently in manpower discussions and this paper attempts an evaluation of its predictive ability and economic interpretation subject to the limits imposed by the data available for the British engineering industry. It is argued that such a model plays a useful initial role in the development of models for sectoral manpower forecasting but must lead on to a more sensitive treatment of the labour market and the decision problem of investing in human capital.  相似文献   
209.
210.
Thirteen cases of infective endocarditis (IE) diagnosed for the first time at autopsy or, in those patients with a previous diagnosis of IE, not thought to be active at the time of death, are presented. Of the six patients who died within 24 h of the onset of symptoms, two died of obstruction of a valve orifice, two died of sepsis, one died of sepsis and alcoholic cardiomyopathy, and one died of a coronary artery embolus. Of the five patients with symptoms lasting more than 24 h, three died of sepsis and congestive heart failure. One died from sepsis alone and one died from congestive heart failure (CHF). In two patients whose duration of symptoms is unknown, one died of sepsis and CHF, and in the other the mechanism of death is unknown. Predisposing factors present in 11 of 13 patients included alcoholism (three), intravenous (IV) drug abuse (three), prosthetic valves (three), aortic stenosis (two), past rheumatic fever (one), and nonstenotic congenitally bicuspid valves (two). The reasons for no antemortem diagnosis were a missed or incorrect clinical diagnosis in three patients seen by a physician shortly before death, no signs or symptoms or found dead (four), non-specific signs and symptoms (three), refusal of medical treatment (one), and a solitary lifestyle (one); there was insufficient information about one patient. Individuals with needle tracks, generalized petechiae. Osler's nodes, splinter hemorrhages, intravenous catheters, pacemaker wires, and infected aortic-valve (A-V) shunts are at risk of IE. Blood and the vegetations should be cultured. The attending physician should be notified of the diagnosis in such cases.  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