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   1857篇
  免费   66篇
各国政治   126篇
工人农民   88篇
世界政治   215篇
外交国际关系   105篇
法律   890篇
中国政治   10篇
政治理论   466篇
综合类   23篇
  2023年   16篇
  2021年   9篇
  2020年   26篇
  2019年   44篇
  2018年   46篇
  2017年   58篇
  2016年   70篇
  2015年   37篇
  2014年   64篇
  2013年   266篇
  2012年   50篇
  2011年   52篇
  2010年   38篇
  2009年   52篇
  2008年   63篇
  2007年   63篇
  2006年   38篇
  2005年   47篇
  2004年   63篇
  2003年   51篇
  2002年   46篇
  2001年   57篇
  2000年   63篇
  1999年   46篇
  1998年   41篇
  1997年   31篇
  1996年   21篇
  1995年   14篇
  1994年   28篇
  1993年   25篇
  1992年   32篇
  1991年   37篇
  1990年   37篇
  1989年   23篇
  1988年   27篇
  1987年   22篇
  1986年   21篇
  1985年   21篇
  1984年   20篇
  1983年   17篇
  1982年   16篇
  1981年   10篇
  1980年   9篇
  1979年   16篇
  1978年   9篇
  1977年   8篇
  1976年   10篇
  1974年   7篇
  1973年   10篇
  1972年   8篇
排序方式: 共有1923条查询结果,搜索用时 15 毫秒
151.
152.
The authors are privileged to have been provided with correspondence about a dispute over the ongoing storage of genetic material (as Guthrie Cards) in Victoria. The correspondence details confusion over the roles of government and the private sector service provider in accounting for the storage, use and destruction of these stored genetic materials collected as part of a government public health program. The purpose in publishing this account is to highlight the present inadequacies in current practices and the ongoing potential for a crisis in the management of collected genetic materials through a lack of appropriate regulation, transparency and accountability. The article suggests measures to remedy some of the existing inadequacies in contractual arrangements and recommends that the government retain ownership and control of both the genetic materials and the derived information to ensure some accountability in the present legal environment.  相似文献   
153.
To evaluate pathophysiological significance of post-mortem urinary myoglobin levels in determining the cause of death, we investigated 210 forensic autopsy cases, partially in comparison with serum levels. Post-mortem serum myoglobin levels were extraordinary high in most cases possibly due to post-mortem change. Urinary myoglobin levels did not correlate with the serum levels, showing possible post-mortem elevation in cases of a prolonged post-mortem period over 48h. A high (>1000 ng/ml), moderate (100-1000 ng/ml), slight (50-100 ng/ml) and not significant (<50 ng/ml) elevation of urinary myoglobin were observed in 26, 43, 31 and 110 cases, respectively. Half the highly elevated cases were those with a survival time over 24h. In cases of minor muscle injury such as head trauma, elevation of urinary myoglobin level was closely related to longer survival. In acute/subacute deaths with a post-mortem interval within 48h, a significant difference was observed in relation to the blood carboxyhemoglobin (COHb) levels of fire victims: myoglobinuria over 100 ng/ml was more frequently and markedly observed in cases with COHb below 60% than over 60%, suggesting muscle damage in fatal burns. Similar elevation was observed in heat stroke victims, and also in some cases of acute and subacute death from polytrauma, asphyxiation, drowning, electricity and spontaneous cerebral bleeding, but not in myocardial infarction. Thus, it was suggested that high post-mortem urinary myoglobin levels in acute and subacute death cases may be a possible indicator of antemortem massive skeletal muscle damage as well as exertional muscle hyperactivity or convulsive disorders associated with hypoxia.  相似文献   
154.
The key component of the PharmChek sweat patch, the membrane, has been tested for the passage of externally applied materials. Drugs in the uncharged state rapidly penetrated the membrane but charged species were greatly slowed. In basic media, detectable concentrations of cocaine, methamphetamine, and heroin were observed at the earliest collection time (ca. 30 s), after drugs were placed on the outside of the membrane. Drug concentrations increased over the 2 h time course, when amounts detected (1710 ng cocaine, 1060 ng methamphetamine, 550 ng heroin per pad at 2 h) represented 5-17% of the drug deposited on the surface of the sweat patch.Drugs externally applied to human skin were shown to bind readily. Drugs deposited on the skin of drug-free volunteers several days prior to application of the sweat patch were not completely removed by normal hygiene or the cleaning procedures recommended before application of the sweat patch. Even 6 days of normal hygiene did not remove all drugs from externally contaminated skin and positive sweat patches resulted. A mechanism for passage of drugs through the sweat patch membrane, a mechanism for retention of drugs on skin, and a redesign of the sweat patch and modification of its use to reduce external contamination are proposed. Appropriate care should be taken in the interpretation of positive results from a sweat patch test until more research is conducted.  相似文献   
155.
Hemorrhagic disease of the newborn (HDN) is usually a self-limiting hemorrhagic disorder of childhood that occurs as a result of vitamin K deficiency. It may be defined as early or late form depending on the time of onset related to birth. HDN is recognized as one of several bleeding disorders that can mimic the findings of nonaccidental head injury and may lead to a mistaken diagnosis of child abuse. We present a single fatal case of late-onset HDN with illustration of hematologic assays that can be performed to assist the pathologist in making the correct diagnosis of HDN.  相似文献   
156.
Editor's Preface     
Law and Philosophy -  相似文献   
157.
i. Oman and Southeastern Arabia: A Bibliographic Survey. By Michael Owen Shannon. Boston, Mass., G.K.Hall & Co., 1978. pp.xvi, 165. $18.00.

ii. Türk Dili ve Edebiyati Ansiklopedisi: Devirler/Isimler/ Eserler/Terimler. Istanbul, Dergah Yayinlari, 1977. TL600 (for 2 vols.).

iii. Arab‐Israeli conflict: a historical, political, social and military bibliography. By Ronald M.De Vore. Oxford, Clio Press, 1976, pp.273. £10.45.

Conflict in the Middle East from October 1973 to July 1976: a selected bibliography. By Michael Rubner. Los Angeles, Center for the Study of Armament and Disarmament, California State University, 1977. pp.83. $3.00.

The Palestine Question: a select bibliography. Compiled from the holdings of the Dag Hammarskj?ld Library, United Nations. New York, United Nations, 1976. pp.63. £3.25 (Distributed in the U.K. by H.M.S.O.).

iv. Middle East Contemporary Survey: Volume I 1976–77.

Edited by Colin Legum. Tel Aviv, Shiloah Center for Middle Eastern and African Studies, University of Tel Aviv, and New York and London, Holmes and Meier, 1978. pp.xxiv, 684. £32.50.

v. The Modern Middle East: A Guide to Research Tools in the Social Sciences. By Reeva S.Simon. Boulder, Colorado, Westview Press, 1978. pp.xv, 283. £6.10.

vi. Gustav Meisels, Reference Literature to Arabic Studies, a bibliographical guide. Tel Aviv, University Publishing Projects Ltd., 1978. pp.xiv + 251.

vii. Saudi Arabia (World Bibliographical Series Vol.5).

Compiled by Frank A.Clements. Oxford and Santa Barbara, Clio Press, 1979. pp.xiv, 195. £16.75.

viii. The Records of the British Residency and Agencies in the Persian Gulf. IOR R/15. (India Office Records: Guides to Archive Groups). By Penelope Tuson. London, India Office Library and Records, 1979. pp.xix, 188. Pl.6. Index. £21.95.

ix. Modern Syria: An Introduction to the Literature. Compiled by C.H.Bleaney. Durham University, Centre for Middle Eastern and Islamic Studies (Occasional Papers Series, no.6). 1979. £4.00.

x. The Encyclopaedia of Islam. New Edition: Encyclopédie de 1'Islam. Nouvelle édition. Index to Volumes/aux [sic: read ‘des‘] Tomes I‐III. Compiled by/Établi par H.& J.D. Pearson. Edited by/Publié par E.van Donzel. Leiden, Brill/Paris, G.P.Maisonneuve & Larose S.A., 1979. pp.viii, 195. 60 guilders.  相似文献   

158.
159.
Forensic hair examiners using traditional microscopic comparison techniques cannot state with certainty, except in extremely rare cases, that a found hair originated from a particular individual. They also cannot provide a statistical likelihood that a hair came from a certain individual and not another. There is no data available regarding the frequency of a specific microscopic hair characteristic (i.e., microtype) or trait in a particular population. Microtype is a term we use to describe certain internal characteristics and features expressed when observing hairs with unpolarized transmitted light. Courts seem to be sympathetic to lawyer's concerns that there are no accepted probability standards for human hair identification. Under Daubert, microscopic hair analysis testimony (or other scientific testimony) is allowed if the technique can be shown to have testability, peer review, general acceptance, and a known error rate. As with other forensic disciplines, laboratory error rate determination for a specific hair comparison case is not possible. Polymerase chain reaction (PCR)-based typing of hair roots offer hair examiners an opportunity to begin cataloging data with regard to microscopic hair association error rates. This is certainly a realistic manner in which to ascertain which hair microtypes and case circumstances repeatedly cause difficulty in association. Two cases are presented in which PCR typing revealed an incorrect inclusion in one and an incorrect exclusion in another. This paper does not suggest that such limited observations define a rate of occurrence. These cases illustrate evidentiary conditions or case circumstances which may potentially contribute to microscopic hair association errors. Issues discussed in this review paper address the potential questions an expert witness may expect in a Daubert hair analysis admissibility hearing.  相似文献   
160.
In this article, we identify legal knowledge as a key difference between workers who desire workplace change and those who do not. Based on surveys with 121 day laborers, we find that not all day laborers are equally dissatisfied with their jobs, despite uniformly difficult working conditions. Some day laborers do not want to make any real changes to the day labor industry, while others desire a range of industry changes, from higher wages to greater government regulation and unionization. A key difference between these workers is their knowledge of employment law: Those who know the law are more likely to desire workplace change.  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