全文获取类型
收费全文 | 13040篇 |
免费 | 405篇 |
专业分类
各国政治 | 842篇 |
工人农民 | 485篇 |
世界政治 | 1031篇 |
外交国际关系 | 694篇 |
法律 | 6896篇 |
中国政治 | 88篇 |
政治理论 | 3292篇 |
综合类 | 117篇 |
出版年
2021年 | 82篇 |
2020年 | 173篇 |
2019年 | 231篇 |
2018年 | 275篇 |
2017年 | 332篇 |
2016年 | 341篇 |
2015年 | 217篇 |
2014年 | 299篇 |
2013年 | 1776篇 |
2012年 | 315篇 |
2011年 | 318篇 |
2010年 | 315篇 |
2009年 | 320篇 |
2008年 | 324篇 |
2007年 | 393篇 |
2006年 | 373篇 |
2005年 | 373篇 |
2004年 | 367篇 |
2003年 | 370篇 |
2002年 | 349篇 |
2001年 | 392篇 |
2000年 | 344篇 |
1999年 | 319篇 |
1998年 | 182篇 |
1997年 | 166篇 |
1996年 | 158篇 |
1995年 | 150篇 |
1994年 | 165篇 |
1993年 | 141篇 |
1992年 | 201篇 |
1991年 | 242篇 |
1990年 | 215篇 |
1989年 | 207篇 |
1988年 | 211篇 |
1987年 | 229篇 |
1986年 | 225篇 |
1985年 | 210篇 |
1984年 | 182篇 |
1983年 | 184篇 |
1982年 | 128篇 |
1981年 | 146篇 |
1980年 | 105篇 |
1979年 | 156篇 |
1978年 | 116篇 |
1977年 | 105篇 |
1976年 | 84篇 |
1975年 | 95篇 |
1974年 | 101篇 |
1973年 | 93篇 |
1972年 | 70篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
981.
目的 探讨唾液酯酶( Set)多态性在法医学亲权鉴定和个体识别方面的应用价值。方法 应用聚丙烯酰胺凝胶盘状电泳及固蓝 RR染色方法,调查了 114名中国人 Set的表型分布及基因频率,用χ 2检验进行统计学分析。结果 中国人酯酶表型频率 Set F 22.81%, Set FS 50.88%, Set S 26.31% ;基因频率为 SetF 0.482 5, SetS 0.517 5;非父排除机率为 0.187 5,个体识别率为 0.619 9。结论 Set有较高的父权排除率和个体识别率,可作为法医学亲权鉴定和个体识别的重要标记系统之一。 相似文献
982.
线粒体 DNA突变与心肌病关系的研究进展 总被引:1,自引:0,他引:1
人类某些疾病与线粒体DNA(mtDNA)基因组缺陷有关.本文就mtDNA突变与缺血性心肌病和肥厚型心肌病关系的研究加以回顾.目前的研究大多认为心肌缺血缺氧致氧化磷酸化紊乱,产生氧自由基损伤mtDNA,以及缺氧致氧化磷酸化过度诱导而损伤mtDNA,慢性损伤积累终致mtDNA片断缺失或点突变,主要表现出mtDNA5.0kb、7.4kb缺失及细胞色素b(cytb)基因上C15452A点突变;tRNA基因保守序列突变,致肌肉收缩蛋白合成缺陷,缺陷的收缩蛋白持续而无效的收缩可能会增加心肌对ATP的代谢需求,因此导致心肌肥厚. 相似文献
983.
Szejnwald Brown Halina Angel David P. Broszkiewicz Roman Krzyśków Barbara 《Policy Sciences》2001,34(3-4):247-271
The societal transformation underway in Poland createda fundamental challenge to the occupational health and safety system, as the ideological and administrative principles on which it was founded vanished along with the communist-dominated regime. This paper examines the regulatory reform in Poland during the 1990s: its structural elements, implementation record and future prospects. Drawing on five case studies of privatized firms, a mailed questionnaire, and policy and institutional analysis, we find that Poland had considerable success in developing an effective regulatory system for managing occupational health hazards in privatized sector while also achieving considerable socioeconomic progress. The fundamental legitimacy of the regulators and regulatory process, the availability of information about firms and regulatory intents, and the capacity for case-specific decision making, are among the key explanatory factors. The case-specific implementation in Poland is consistent with models advocated by several authors in relation to other industrialized European economies (termed variously as negotiated compliance, tit-for-tat, cooperation-deterrence), despite a uniquely Polish context related to the continuing legacy of the communist era. The study also shows how in Poland a good fit between regulatory institutions and policies on the one hand, and their social context on the other hand, contributes to the effectiveness of the regulatory system. 相似文献
984.
985.
A J Ruttenber H B McAnally C V Wetli 《The American journal of forensic medicine and pathology》1999,20(2):120-127
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
986.
This paper re-examines some of the current theoretical models and paradigms of criminal justice in England and Wales based on an analysis of national arrest statistics between 1981 and 1997. The data show that there has been a large increase in the number of arrests in the period but the number of people prosecuted has declined. An increasing number of people are being arrested and released without any further action. The principal argument is that there has been a radical shift in power away from the formal open and public system of justice towards a more informal closed system. The paper concludes that while these trends lend support to a number of theoretical perspectives on the criminal justice process, particularly Choongh's social disciplinary model, the radical transformation which has taken place in the form of criminal justice can only be understood within the broader politics and economic structures of modern Britain. 相似文献
987.
988.
989.
990.
The Fx5 Fibre Finder has been developed by Foster & Freeman Ltd to automatically search tape lifts for coloured fibres specified by the operator. Experiments and casework studies have been conducted to assess primarily the performance of the instrument but also, where possible, to compare it with manual searching. Tape lifts have always been manually searched at this laboratory and it is a laborious task. The use of a machine such as the Fx5 would release a scientist from many hours of low power microscopy to be free for other duties and therefore could be a valuable labour saving device in forensic textile examination. 相似文献