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   18158篇
  免费   577篇
  国内免费   5篇
各国政治   761篇
工人农民   772篇
世界政治   1210篇
外交国际关系   595篇
法律   11821篇
中国共产党   6篇
中国政治   163篇
政治理论   3227篇
综合类   185篇
  2020年   240篇
  2019年   284篇
  2018年   349篇
  2017年   410篇
  2016年   425篇
  2015年   308篇
  2014年   334篇
  2013年   1626篇
  2012年   485篇
  2011年   521篇
  2010年   413篇
  2009年   435篇
  2008年   531篇
  2007年   576篇
  2006年   552篇
  2005年   509篇
  2004年   501篇
  2003年   529篇
  2002年   461篇
  2001年   765篇
  2000年   632篇
  1999年   522篇
  1998年   262篇
  1997年   182篇
  1996年   216篇
  1995年   184篇
  1994年   215篇
  1993年   214篇
  1992年   364篇
  1991年   402篇
  1990年   380篇
  1989年   343篇
  1988年   385篇
  1987年   323篇
  1986年   381篇
  1985年   328篇
  1984年   257篇
  1983年   251篇
  1982年   190篇
  1981年   216篇
  1980年   140篇
  1979年   196篇
  1978年   141篇
  1977年   129篇
  1976年   109篇
  1975年   145篇
  1974年   157篇
  1973年   124篇
  1972年   125篇
  1969年   110篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
191.
192.
193.
194.
In this article we examine how increasing the reimbursement of physicians and expanding Medicaid eligibility affect access to care for children in Cook County, Illinois, which overlies Chicago. Using Medicaid claims and other data at the zip-code level, we compare the places where Medicaid children live with the places where all the physicians who treat children and those who accept Medicaid patients have their practices. Our findings suggest that the recent changes in legislation are unlikely to benefit extremely poor children, who are more likely to live in depressed inner-city areas, where there are few physicians. "Near-poor" children whose homes are dispersed throughout the county, who are now eligible for Medicaid as a result of the recent changes, are likely to see improvements in their access to care. Further changes in policy, aimed at enhancing the capacity of institutions providing care, could improve access for the children of the inner city.  相似文献   
195.
196.
The Iran-Contra affair is an example of the type of event that is expected to give rise to a rally of public opinion behind the president. However, the public's response to this event, uncharacteristically, was a sharp decrease in support for President Reagan. This case study constitutes an attempt to explore the sources of the public opinion response to foreign policy events. Statements of political elites, news coverage and commentary, and public opinion assessments are examined to test the patriotism, priming, and opinion leadership explanations of the rally phenomenon. The actions of opinion leaders appears to provide the best explanation of the differential public response to the Iran-Contra affair.  相似文献   
197.
A study of 82 suicides during 1982-1986 that were committed by jumping from buildings was performed using the case files of the Office of the Medical Examiner of Metropolitan Dade County in Miami, Florida, U.S.A. The analysis involved the age, race, and sex of the victim along with the results of toxicologic studies and the cause of death. Additionally, the decedent's place of residence, location of the suicide, height of the building, and the reason for the suicide were investigated. Whether or not a note was left by the decedent was also ascertained. The suicidal "jumper" most commonly was a white man who was greater than 60 years of age who died from the resultant multiple injuries. The victim commonly was sober and drug free at the time of the incident. In approximately two-thirds of the cases, the location of the suicide was the victim's residence, which frequently was an apartment or condominium-type dwelling that was seven floors or higher from the ground. The victim often had experienced depression prior to the incident and did not usually leave a suicide note. This article compares the Dade County cases with others that have been studied and discusses the reasons why jumping from a building may have been chosen as the suicidal mechanism.  相似文献   
198.
During preliminary examination of the body of a homicide victim, a peculiar red "fiber" was noticed and recovered. Initially believing this to be a carpet fiber, the item was subjected to fiber analysis. It was found to be a short coiled particle not like any known natural or synthetic fabric fiber. Subsequent examinations determined this "fiber" to be the larva of a common freshwater midge (Diptera; Chironomidae). Chironomid larvae have been observed on other bodies recovered from freshwater environments. Entomological studies of this organism have led to the conclusion that the presence of chironomid larvae indicates submersion of the body.  相似文献   
199.
Isoenzyme band patterns of animal blood erythrocyte acid phosphatase (EAP) and phosphoglucomutase-1 (PGM) were studied by isoelectric focusing on ultrathin polyacrylamide gels. For blood from all animals tested (dog, cat, cow, sheep, and goat), the overall band patterns for both isoenzymes were different from those of the most common human types of these enzymes, although some animal EAP and PGM bands appeared in the human band areas. When mixtures of human and animal red blood cells were studied, it was found that misinterpretation of human types was possible only if the overall band pattern of the mixtures was ignored. For the animal blood tested, the strong PGM bands appearing outside the human band areas could be used as "markers" for the possible presence of animal blood in the samples tested.  相似文献   
200.
Programme based on mathematical model of the process of dead body temperature changing was developed for estimation of postmortem interval. Automatic retrieval of problem solution was performed on programmable microcalculators of "Electronica MK-61" type using adaptive approach. Diagnostical accuracy in case of dead body being preserved in permanent cooling conditions is +/- 3%.  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