全文获取类型
收费全文 | 13030篇 |
免费 | 707篇 |
专业分类
各国政治 | 764篇 |
工人农民 | 397篇 |
世界政治 | 1071篇 |
外交国际关系 | 673篇 |
法律 | 7409篇 |
中国政治 | 83篇 |
政治理论 | 3230篇 |
综合类 | 110篇 |
出版年
2023年 | 71篇 |
2021年 | 86篇 |
2020年 | 248篇 |
2019年 | 310篇 |
2018年 | 336篇 |
2017年 | 394篇 |
2016年 | 406篇 |
2015年 | 306篇 |
2014年 | 342篇 |
2013年 | 1745篇 |
2012年 | 317篇 |
2011年 | 333篇 |
2010年 | 367篇 |
2009年 | 395篇 |
2008年 | 317篇 |
2007年 | 368篇 |
2006年 | 353篇 |
2005年 | 384篇 |
2004年 | 402篇 |
2003年 | 365篇 |
2002年 | 358篇 |
2001年 | 428篇 |
2000年 | 368篇 |
1999年 | 323篇 |
1998年 | 188篇 |
1997年 | 152篇 |
1996年 | 156篇 |
1995年 | 167篇 |
1994年 | 177篇 |
1993年 | 164篇 |
1992年 | 232篇 |
1991年 | 240篇 |
1990年 | 205篇 |
1989年 | 221篇 |
1988年 | 187篇 |
1987年 | 200篇 |
1986年 | 191篇 |
1985年 | 195篇 |
1984年 | 156篇 |
1983年 | 174篇 |
1982年 | 126篇 |
1981年 | 132篇 |
1980年 | 92篇 |
1979年 | 146篇 |
1978年 | 102篇 |
1977年 | 89篇 |
1976年 | 80篇 |
1975年 | 58篇 |
1974年 | 68篇 |
1973年 | 70篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
911.
Fractures in bones of the skull base (BSB) are preconditioned by the contact zone of interaction between the two below surfaces, i.e. the trace-forming one (object) and the trace-receiving one (bone). On the basis of their independent research, the authors suggest a set of criteria for the expert evaluation of fractures in BSB for the purpose of specifying the properties of the trauma-causing object, which is made with due regard for the anatomic specific features of the trauma zone. 相似文献
912.
Eighteen cadavers of persons, who died of acute and chronic alcohol and drug intoxication (ephedron-addiction), were used to study the changes in the spinal nerve plexuses and external genitals. The activity of acetylcholinesterase and of NADPH-diaphorase was determined histochemically; the adrenergic nerve fibers were detected by a glyoxyl-acid technique. Rectified changes in the relative density of adrenal-cholinergic- and nitroxydergic structures and in the activity of mediators in different intoxications were found. The chronic intoxication by alcohol and ephedron was accompanied by a reduced activity of enzymes involved in the metabolism of acetylcholine, nitric oxide and catecholamines. A lower density was observed in the nerve fibers that contained the examined substances. The results can be used as an additional criterion in evaluating the male sexual-function status. 相似文献
913.
914.
915.
We develop an empirical estimator directly from an extensive-formcrisis bargaining game with incomplete information and discussits features and limitations. The estimator makes it possibleto draw inferences about states' payoffs from observationaldata on crisis outcomes while remaining faithful to the theorizedstrategic and informational structure. We compare this estimatorto one based on a symmetric information version of the samegame, using the quantal response equilibrium proposed in thiscontext by Signorino (1999, American Political Science Review93:279298). We then address issues of identificationthat arise in trying to learn about actors' utilities by observingtheir play of a strategic game. In general, a number of identifyingrestrictions are needed in order to pin down the distributionof payoffs and the effects of covariates on those payoffs. 相似文献
916.
917.
918.
919.
920.