全文获取类型
收费全文 | 10587篇 |
免费 | 260篇 |
专业分类
各国政治 | 699篇 |
工人农民 | 263篇 |
世界政治 | 811篇 |
外交国际关系 | 526篇 |
法律 | 5813篇 |
中国共产党 | 2篇 |
中国政治 | 42篇 |
政治理论 | 2562篇 |
综合类 | 129篇 |
出版年
2020年 | 119篇 |
2019年 | 140篇 |
2018年 | 216篇 |
2017年 | 245篇 |
2016年 | 269篇 |
2015年 | 188篇 |
2014年 | 217篇 |
2013年 | 1357篇 |
2012年 | 286篇 |
2011年 | 294篇 |
2010年 | 233篇 |
2009年 | 278篇 |
2008年 | 340篇 |
2007年 | 308篇 |
2006年 | 283篇 |
2005年 | 252篇 |
2004年 | 256篇 |
2003年 | 238篇 |
2002年 | 255篇 |
2001年 | 373篇 |
2000年 | 338篇 |
1999年 | 285篇 |
1998年 | 141篇 |
1997年 | 154篇 |
1996年 | 120篇 |
1995年 | 134篇 |
1994年 | 136篇 |
1993年 | 124篇 |
1992年 | 184篇 |
1991年 | 222篇 |
1990年 | 181篇 |
1989年 | 210篇 |
1988年 | 177篇 |
1987年 | 176篇 |
1986年 | 213篇 |
1985年 | 141篇 |
1984年 | 148篇 |
1983年 | 158篇 |
1982年 | 108篇 |
1981年 | 94篇 |
1980年 | 82篇 |
1979年 | 127篇 |
1978年 | 84篇 |
1977年 | 77篇 |
1976年 | 71篇 |
1975年 | 73篇 |
1974年 | 101篇 |
1973年 | 82篇 |
1972年 | 69篇 |
1971年 | 65篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
91.
92.
93.
94.
95.
96.
97.
Significance of functional and nutritive pulmonary circulation for vital reactions in the form of embolisms 总被引:2,自引:0,他引:2
G Adebahr 《Zeitschrift für Rechtsmedizin》1988,100(1):55-64
The functional and nutritive circulation in the lungs is connected by anastomoses between the pulmonary and bronchial arteries. The anastomoses have the structure of blocked arteries from which arteriovenous anastomoses proceed to the peribronchial plexus. The pulmonary artery is provided with a flow impulse by the anastomoses, and oxygen-containing blood is admixed with the venous blood, thus forming an "aortalization" in the lungs. By diverting the bloodstream, venous blood can reach the bronchial artery. The peculiarities of the lung circulation are important for vital reactions in the form of macro- and microembolisms. Macroembolisms prove the functionality of the system if branches of the pulmonary artery are closed before the arteries are blocked. A hemorrhagic infarction either arises or does not arise, and the hemorrhagic infarction cannot exceed a certain limit. A microembolism is over and above the anastomoses. If the microembolism is greater, pressure in the arteria pulmonaris can cause blood from the pulmonary artery to overflow into the bronchial artery. Because arteriovenous anastomoses arise from the blocked arteries, microemboli can now reach the systemic circulation. Thus, the system described can explain the passage of microemboli into the systemic circulation, avoiding the capillaries of the lungs; on the other hand, larger microembolisms can prove the functionality of the system. 相似文献
98.
99.
Lobbyists, entrenched forces in congress and self-interested friends will try to stymie Clinton's efforts. A look at four key arenas of combat. 相似文献
100.
Peter Atkins Greg Bagley Jim Bartoo Michael Bayer David Beatty David Brown Terry Cook Reggie Fairchild David Foster Bruno Gentil Gordon Goetzmann Michael Green Jim Hamann Rustom Irani Greg Lee Lynn Little Jim Mariani Tom McGuire Doug Merrill Gentaro Murakami Todd Naiven Taisuke Nomura Doug Paul Joe Rodriguez Stephen Silver Howard Suskind Mitsuhiro Tsuchiya Mike Wais Jeff Wright Jonathan Zaremski 《The Journal of Technology Transfer》1992,17(1):58-67
The United States today faces a loss of influence as a world power, a reduction in American independence as a policymaker, and a decline in the standard of living on which Americans have come to depend. History teaches that nations weaker and less productive than the United States can rise to become economic powerhouses and rapidly increase their standards of living. History also teaches that nations failing to recognize their fundamental problems will inevitably decline. American politicians must face what is abundantly clear: the United States is losing ground and must act quickly to reverse its course. This White Paper outlines what must be done. Information about the nation's current status must be analyzed and communicated. Incentives to improve the level of competence in government must be provided and maintained. The emphasis of government policy must be changed to reflect broad economic and technological interests as opposed to special interests. Savings must be encouraged and increased. Infrastructure must be improved Tax laws must be modified to help bring these changes about. Economic and technological issues must be elevated to the importance they require. American thinking must reflect the new realities: that the age of leadership through military power is over, that the requirements for success in the world of the 1990s and beyond require a sound and growing economy that is internationally competitive. The US can accomplish these goals only through foundation-shaking, comprehensive, fundamental changealong the lines we propose herein.This paper is the executive summary (with minor editing modifications) of a white paper that is available from Cornell University's Johnson Graduate School of Management. 相似文献