全文获取类型
收费全文 | 10950篇 |
免费 | 321篇 |
专业分类
各国政治 | 427篇 |
工人农民 | 438篇 |
世界政治 | 742篇 |
外交国际关系 | 304篇 |
法律 | 6881篇 |
中国政治 | 73篇 |
政治理论 | 2311篇 |
综合类 | 95篇 |
出版年
2020年 | 122篇 |
2019年 | 180篇 |
2018年 | 211篇 |
2017年 | 239篇 |
2016年 | 235篇 |
2015年 | 188篇 |
2014年 | 205篇 |
2013年 | 990篇 |
2012年 | 234篇 |
2011年 | 282篇 |
2010年 | 222篇 |
2009年 | 283篇 |
2008年 | 288篇 |
2007年 | 286篇 |
2006年 | 275篇 |
2005年 | 248篇 |
2004年 | 241篇 |
2003年 | 249篇 |
2002年 | 250篇 |
2001年 | 427篇 |
2000年 | 372篇 |
1999年 | 296篇 |
1998年 | 161篇 |
1997年 | 124篇 |
1996年 | 140篇 |
1995年 | 134篇 |
1994年 | 135篇 |
1993年 | 138篇 |
1992年 | 234篇 |
1991年 | 254篇 |
1990年 | 241篇 |
1989年 | 249篇 |
1988年 | 226篇 |
1987年 | 223篇 |
1986年 | 264篇 |
1985年 | 256篇 |
1984年 | 230篇 |
1983年 | 214篇 |
1982年 | 151篇 |
1981年 | 127篇 |
1980年 | 113篇 |
1979年 | 151篇 |
1978年 | 85篇 |
1977年 | 111篇 |
1976年 | 95篇 |
1975年 | 71篇 |
1974年 | 89篇 |
1973年 | 83篇 |
1972年 | 78篇 |
1971年 | 69篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
781.
A R Copeland 《The American journal of forensic medicine and pathology》1985,6(2):175-179
Autopsy cases of deaths from handgun wounds were studied. Survival times were estimated from time of the incident until the time of pronouncement on police reports. Two groups were apparent--short-term and non-short-term survivors. These groups were compared statistically with respect to age, race, sex, Spanish surname, alcohol, drugs detected at autopsy, caliber of projectile, frequency of shots, and location of injury. 相似文献
782.
R.C. Carpenter 《Forensic science international》1985,27(3):165-170
A discrete nebulisation technique has been developed for the multi-element analysis of 100-μl solution droplets by inductively coupled plasma-optical emission spectrometry (ICP-OES). The technique increases analytical speed and uses very small solution volumes with only a slight degradation in detection limits when compared to continuous solution introduction.To evaluate its suitability in casework, small alloy fragments were produced by cutting with a hacksaw, sample division and filing. The analysis of fragments from two different brasses indicated that quantitative data could be obtained from fragments as small as 10 μg. The accurate determination of lead, a non-homogeneous constituent of leaded brasses, required sample sizes an order of magnitude greater. Analysis of an alloy of fine grain structure (copper-nickel) demonstrated that quantitative data could be obtained from samples weighing a few micrograms or less. 相似文献
783.
784.
785.
786.
787.
This article is a nontechnical presentation of the debate that has gone on during the past decade over whether the U.S. social security system has depressed private saving in the economy. The heart of the article is an assessment of economist Martin Feldstein's original evidence, presentation of the alternative evidence that concluded that currently available historical data do not support the proposition that social security reduces private saving, and an evaluation of the contradictory evidence presented by Feldstein in response to the alternative evidence. The article concludes that, although the total body of evidence is inconclusive, the historical evidence fails to support the hypothesis that social security has reduced private saving. The Office of Research, Statistics, and International Policy, as part of its ongoing research mission, investigates the interrelationship between social security and the economy. This article presents an examination of one of several aspects of this relationship relevant to public policy considerations and is intended to make previously published technical papers available to a broader audience. 相似文献
788.
789.
790.