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   15457篇
  免费   476篇
各国政治   552篇
工人农民   1290篇
世界政治   649篇
外交国际关系   522篇
法律   9731篇
中国政治   40篇
政治理论   3113篇
综合类   36篇
  2020年   166篇
  2019年   172篇
  2018年   1440篇
  2017年   1402篇
  2016年   1226篇
  2015年   268篇
  2014年   207篇
  2013年   788篇
  2012年   345篇
  2011年   1077篇
  2010年   1213篇
  2009年   801篇
  2008年   891篇
  2007年   853篇
  2006年   180篇
  2005年   226篇
  2004年   351篇
  2003年   301篇
  2002年   164篇
  2001年   312篇
  2000年   256篇
  1999年   228篇
  1998年   106篇
  1997年   78篇
  1996年   86篇
  1995年   107篇
  1994年   107篇
  1993年   89篇
  1992年   151篇
  1991年   158篇
  1990年   145篇
  1989年   156篇
  1988年   125篇
  1987年   138篇
  1986年   127篇
  1985年   133篇
  1984年   110篇
  1983年   123篇
  1982年   88篇
  1981年   79篇
  1980年   56篇
  1979年   115篇
  1978年   77篇
  1977年   68篇
  1976年   50篇
  1975年   47篇
  1974年   56篇
  1973年   55篇
  1972年   45篇
  1968年   40篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
961.
家兔死后眼玻璃体液锌、镍含量与 PMI关系的研究   总被引:6,自引:3,他引:3  
Gong ZQ  Xu XM  Zeng XB  Sun YG  Wang DW 《法医学杂志》2001,17(3):129-131
目的寻找一种精确推定PMI的方法。方法应用电感耦合等离子体质谱(ICP-MS),检测了家兔死后96小时内眼玻璃体液锌、镍元素含量,探讨其与PMI的相关性。结果家兔死后24h内眼玻璃体液锌、镍元素含量与PMI显著相关,可作为推定早期PMI的参考指标,其二项式回归方程分别为y=0.1404x2-1.3351x+3.8298(R2=0.9202)、y=0.0043x2-0.0596x+0.2665(R2=0.9103)。结论家兔眼玻璃体液中Zn、Ni元素含量变化是推定早期PMI的参考指标之一。  相似文献   
962.
963.
After Chile reformed its social security system in 1981, several other Latin American countries and certain Central and Eastern European (CEE) countries implemented the Chilean model, with some variations: either a single- or multitier system, or with a period of transition to take care of those in the labor force at the time of the change. The single-tier version consists of individual accounts in pension fund management companies. Multi-tier systems retain some form of public program and add mandatory individual accounts. Most of the CEE countries did not want to incur the high transition costs associated with the Chilean model. The switch to a market economy had already strained their economies. Also, the countries' desire to adopt the European Union's Euro as their currency--a move that required a specific debt ceiling--limited the amount of additional debt they could incur. This article describes the CEE reforms and makes some comparisons with the Latin American experience. Most of the CEE countries have chosen a mixed system and have restructured the pay-as-you-go (PAYGO) tier, while the Latin American countries have both single- and multi-tier systems. Some CEE countries have set up notional defined contribution (NDC) schemes for the PAYGO tier in which each insured person has a hypothetical account made up of all contributions during his or her working life. Survivors and disability programs in CEE have remained in the public tier, but in most of the Latin American programs the insured must purchase a separate insurance policy. Issues common to both regions include: Administrative costs are high and competition is keen, which has led to consolidation and mergers among the companies and a large market share controlled by a few companies. Benefits are proportionately lower for women than for men. A large, informal sector is not covered by social security. This sector is apparently much larger in Latin America than in the CEE countries. Issues that are unique to some of the CEE countries include: Individual accounts in Hungary and Poland have proved more attractive than originally anticipated. As a result, contributions to the public PAYGO system in Hungary and Poland fell short of expectations. In several countries, laws setting up the programs were enacted without all the details of providing benefits. For example, in some countries laws must now be drawn up for establishment of annuities because they do not yet exist. Setting up a coherent pension policy has been difficult in some countries because of frequent and significant changes in government. This situation has affected the progress of reform in various stages of development. In general, a definitive assessment of individual accounts in these countries will not be possible until a cohort of retirees has spent most of its career under the new system.  相似文献   
964.
The high rate of infant mortality among native peoples in the Aberdeen Service Area of the Indian Health Service (primarily North and South Dakota) prompted a multi-institutional study of this problem. The study investigators assumed that local coroners or medical examiners would be able to perform suitable death scene investigations. However, during the design portion of the study it became apparent that, with one exception, none of the participating Indian Nations had a death investigator or even a legal mandate to provide death investigation. To allow the study to go forward, and ultimately to better the community health within its service area, the Aberdeen Area Indian Health Service submitted a draft enabling coroner legislation/resolutions to the area tribes. By November of 1996, 6 of the 19 Indian Nations enacted enabling coroner legislation. To facilitate both the study and general death investigation within the area, the Aberdeen Area Indian Health Service since 1993 has held five 2-day death investigation training programs covering a variety of death investigation topics which were attended by 68 participants. Without further recognition of the need for tribal death investigation and additional funding, these gains in tribal death investigation will probably be transitory.  相似文献   
965.
Previous case reports indicate that cocaine-associated rhabdomyolysis and excited delirium share many similar features, suggesting that they may be different stages of the same syndrome. We tested this hypothesis by comparing data from 150 cases of cocaine-associated rhabdomyolysis reported in the medical literature with data from an autopsy registry for 58 victims of fatal excited delirium and 125 victims of fatal acute cocaine toxicity. Patients with rhabdomyolysis are similar to victims of fatal excited delirium with regard to age; gender; race; route of cocaine administration; the experiencing of excitement, delirium, and hyperthermia; and the absence of seizures. Compared with victims of fatal acute cocaine toxicity, patients with rhabdomyolysis are different with regard to each of these variables. Compared with victims of fatal acute cocaine toxicity, both victims of rhabdomyolysis and fatal excited delirium are more likely to be black, male, and younger; to have administered cocaine by smoking or injection; and to have experienced excitement, delirium, and hyperthermia; they are also less likely to have had seizures. Because cocaine-associated rhabdomyolysis and excited delirium have similar clinical features and risk factors, occur in similar populations of drug users, and can be explained by the same pathophysiologic processes, we conclude that they are different stages of the same syndrome. It appears that this syndrome is caused by changes in dopamine processing induced by chronic and intense use of cocaine rather than by the acute toxic effects of the drug.  相似文献   
966.
This study reviews the causes of sudden death of 66 schizophrenic patients who presented to the Office of the Chief Medical Examiner (OCME) for the State of Maryland over a 3-year period from 1994 through 1996. We identified an increased incidence of suicide compared with the general population of OCME cases. This observation is consistent with reports by other investigators. The majority of the deaths were the result of natural diseases, mostly atherosclerotic cardiovascular disease. Accidents, suicides, and 1 homicide were also present in this group.  相似文献   
967.
968.
969.
Tang SB  Guo JY  Liu C  Liang SQ  Wang SB 《法医学杂志》1999,15(2):86-8, 127
Using polymerase chain reaction and silver stain, polymorphism and haplotype study of Y-chromosomal multi-STRs loci: DYS19, DYS389I/II, DYS390 were studied. 111 samples of male were collected from Guangzhou area. 5 alleles were determined in DYS19 locus, 4 alleles in DYS389I locus, 5 alleles in DYS389II locus and 5 alleles in DYS390 locus. Compared with other racial populations, differences of distribution of allele frequencies existed significantly. 72 haplotype were present in this study.  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