全文获取类型
收费全文 | 4719篇 |
免费 | 134篇 |
专业分类
各国政治 | 150篇 |
工人农民 | 213篇 |
世界政治 | 311篇 |
外交国际关系 | 177篇 |
法律 | 3135篇 |
中国政治 | 24篇 |
政治理论 | 820篇 |
综合类 | 23篇 |
出版年
2023年 | 37篇 |
2021年 | 26篇 |
2020年 | 57篇 |
2019年 | 76篇 |
2018年 | 103篇 |
2017年 | 97篇 |
2016年 | 115篇 |
2015年 | 68篇 |
2014年 | 89篇 |
2013年 | 411篇 |
2012年 | 114篇 |
2011年 | 135篇 |
2010年 | 94篇 |
2009年 | 120篇 |
2008年 | 117篇 |
2007年 | 116篇 |
2006年 | 122篇 |
2005年 | 83篇 |
2004年 | 102篇 |
2003年 | 108篇 |
2002年 | 85篇 |
2001年 | 208篇 |
2000年 | 207篇 |
1999年 | 149篇 |
1998年 | 61篇 |
1997年 | 60篇 |
1996年 | 54篇 |
1995年 | 52篇 |
1994年 | 59篇 |
1993年 | 52篇 |
1992年 | 118篇 |
1991年 | 106篇 |
1990年 | 132篇 |
1989年 | 121篇 |
1988年 | 136篇 |
1987年 | 129篇 |
1986年 | 100篇 |
1985年 | 106篇 |
1984年 | 80篇 |
1983年 | 71篇 |
1982年 | 52篇 |
1981年 | 47篇 |
1980年 | 40篇 |
1979年 | 50篇 |
1978年 | 36篇 |
1976年 | 30篇 |
1975年 | 28篇 |
1974年 | 39篇 |
1973年 | 28篇 |
1970年 | 27篇 |
排序方式: 共有4853条查询结果,搜索用时 15 毫秒
971.
Metz Bert Berk Marcel Kok Marcel T. J. van Minnen Jelle G. de Moor Andre Faber Albert 《International Environmental Agreements: Politics, Law and Economics》2001,1(2):167-185
During the 6th Conference of Parties (COP-6) in The Hague, the Netherlands, November 2000, crucial progress on a number of outstanding issues related to the Kyoto Protocol will have to be made to open the way for its early ratification, if not to save it from complete failure. Given the present lack of internal US political support for the Kyoto Protocol, the EU may play a pivotal role in making the Kyoto Protocol agreement a reality even without initial ratification of the US, if its able to provide sufficient leadership. In this overview article we discuss the main issues under negotiation, the problems of finding agreement and opportunities for the EU to catalyse a compromise agreement at COP-6, building on key scientific papers as included in this issue and discussions at the European Forum on Integrated Environmental Assessment Climate Policy Workshop in Amsterdam. Key elements are the inclusion of sinks, the use of the Kyoto Protocol mechanisms as a supplement to domestic action and the international compliance system. Domestic implementation of climate policy is a major factor for the EU's credibility. 相似文献
972.
Here we report about a 35-year-old electrical engineer who was found dead in his study. Postmortem examination revealed that death resulted because of subarachnoid and intraventricular hemorrhage caused by the rupture of an intracranial aneurysm. Right hand and left cheek revealed electrical marks with metallizations on skin, an electric shock was diagnosed to have preceded death. The close temporal correlation suggests that a sudden rise in blood pressure was caused by the electric current and was thus responsible for the rupture of the aneurysm. 相似文献
973.
Current blood-level data are presented for drugs and chemicals of toxicologic interest. The data represent an update of previously published compilations of therapeutic, toxic and lethal blood-levels. 相似文献
974.
H Koyama M Iwasa Y Maeno T Tsuchimochi I Isobe S N Yoshimi M O Jun T Matsumoto T Horii M Nagao 《Forensic science international》2001,124(2-3):221-223
Allele and haplotype frequencies of seven Y-chromosome STR loci from samples of 108 unrelated Japanese males living in Aichi Prefecture. 相似文献
975.
Barriers Inhibiting Industry from Partnering with Universities: Evidence from the Advanced Technology Program 总被引:1,自引:0,他引:1
This paper describes a small, unique set of project data that was assembled as part of a larger study on universities as research partners. Herein, we summarize, to the extent possible, our interpretation of what the project data reveal about barriers, intellectual property (IP) concerns in particular, inhibiting industry from partnering with universities. 相似文献
976.
Erwin J. A. T. Mattijssen MSc Cilia L. M. Witteman PhD Charles E. H. Berger PhD Xiaoyu A. Zheng MSc Johannes A. Soons PhD Reinoud D. Stoel PhD 《Journal of forensic sciences》2021,66(1):96-111
Forensic firearm examination provides the court of law with information about the source of fired cartridge cases. We assessed the validity of source decisions of a computer‐based method and of 73 firearm examiners who compared breechface and firing pin impressions of 48 comparison sets. We also compared the computer‐based method's comparison scores with the examiners' degree‐of‐support judgments and assessed the validity of the latter. The true‐positive rate (sensitivity) and true‐negative rate (specificity) of the computer‐based method (for the comparison of both the breechface and firing pin impressions) were 94.4% and at least 91.7%, respectively. For the examiners, the true‐positive rate was at least 95.3% and the true‐negative rate was at least 86.2%. The validity of the source decisions improved when the evaluations of breechface and firing pin impressions were combined and for the examiners also when the perceived difficulty of the comparison decreased. The examiners were reluctant to provide source decisions for "difficult" comparisons even though their source decisions were mostly correct. The correlation between the computer‐based method's comparison scores and the examiners' degree‐of‐support judgments was low for the same‐source comparisons to negligible for the different‐source comparisons. Combining the outcomes of computer‐based methods with the judgments of examiners could increase the validity of firearm examinations. The examiners' numerical degree‐of‐support judgments for their source decisions were not well‐calibrated and showed clear signs of overconfidence. We suggest studying the merits of performance feedback to calibrate these judgments. 相似文献
977.
978.
979.
980.