全文获取类型
收费全文 | 12314篇 |
免费 | 391篇 |
专业分类
各国政治 | 848篇 |
工人农民 | 478篇 |
世界政治 | 1000篇 |
外交国际关系 | 564篇 |
法律 | 6616篇 |
中国共产党 | 2篇 |
中国政治 | 154篇 |
政治理论 | 2914篇 |
综合类 | 129篇 |
出版年
2020年 | 166篇 |
2019年 | 186篇 |
2018年 | 263篇 |
2017年 | 289篇 |
2016年 | 315篇 |
2015年 | 247篇 |
2014年 | 275篇 |
2013年 | 1658篇 |
2012年 | 299篇 |
2011年 | 401篇 |
2010年 | 309篇 |
2009年 | 322篇 |
2008年 | 347篇 |
2007年 | 336篇 |
2006年 | 317篇 |
2005年 | 284篇 |
2004年 | 311篇 |
2003年 | 338篇 |
2002年 | 313篇 |
2001年 | 429篇 |
2000年 | 404篇 |
1999年 | 369篇 |
1998年 | 204篇 |
1997年 | 176篇 |
1996年 | 163篇 |
1995年 | 142篇 |
1994年 | 140篇 |
1993年 | 147篇 |
1992年 | 210篇 |
1991年 | 212篇 |
1990年 | 185篇 |
1989年 | 189篇 |
1988年 | 201篇 |
1987年 | 196篇 |
1986年 | 211篇 |
1985年 | 191篇 |
1984年 | 170篇 |
1983年 | 203篇 |
1982年 | 131篇 |
1981年 | 98篇 |
1980年 | 105篇 |
1979年 | 119篇 |
1978年 | 101篇 |
1977年 | 88篇 |
1976年 | 93篇 |
1975年 | 73篇 |
1974年 | 75篇 |
1972年 | 65篇 |
1971年 | 68篇 |
1969年 | 61篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
971.
Using Ecological Inference Point Estimates as Dependent Variables in Second-Stage Linear Regressions 总被引:1,自引:0,他引:1
The practice of using point estimates produced by the King ecologicalinference technique as dependent variables in second-stage linearregressions leads to second-stage results that, in general,are inconsistent. This conclusion holds even when all assumptionsbehind King's ecological technique are satisfied. Second-stageinconsistency is a consequence of the fact that King-based pointestimates of disaggregated quantities contain errors correlatedwith the true quantities the estimates measure. Our findingson second-stage inconsistency, as well as a fix that we propose,follow from econometric theory in conjunction with an analysisof simulated and real ecological data sets. 相似文献
972.
This research reports on public opinion surveys on intergovernmentaland federal issues conducted in Canada, Mexico, and the UnitedStates in March and April 2003. In all three countries, respondentsmost often see their federal government as being the least effective,least efficient, and least trustworthy. Respondents from Canadaappear least supportive of their federal government and mostsupportive of their local governments; those from Mexico appearmost supportive of their state governments; respondents fromthe United States appear more "balanced" in their support ofthe various orders of government. Also, far greater regionaldifferences in opinion exist in Canada than in Mexico or theUnited States. Support for more decentralized federalism isfound to be strong in all these federal countries. This researchalso updates long-term trend data for the United States. Comparedwith respondents from previous years, U.S. respondents in 2003showed a measurable uplick in support for the federal government,compared with state and local governments. This support seemsto be a carryover from the terrorist attacks of 11 September2001. 相似文献
973.
974.
975.
976.
977.
978.
We report here the results of mtDNA analysis of remains exhumed in July, 1995 from Mt. Olivet Cemetery in Kearney, Nebraska, that are thought to be those of Jesse James. The remains were poorly preserved, presumably due to wet and slightly acidic soil conditions, and insufficient DNA for analysis was obtained from two bone samples. However, two of four teeth, and two hairs recovered in 1978 from the original burial site on the James Farm, did yield reproducible mtDNA sequences. These mtDNA sequences from the teeth and hairs were all identical, suggesting that they came from the same individual; furthermore, this mtDNA sequence was identical to mtDNA sequences determined from blood samples from two maternal relatives of Jesse James. Therefore, either the remains are indeed those of Jesse James, or they are from an unrelated individual who, by chance, happens to have the same mtDNA sequence. To assess the probability that an unrelated individual would have the same sequence, we searched the forensic mtDNA database, and found that this sequence does not appear among the 2426 mtDNA sequences therein. Hence, the mtDNA analysis supports the identification of the exhumed remains from Mt. Olivet Cemetery as those of Jesse James. 相似文献
979.
980.