全文获取类型
收费全文 | 725篇 |
免费 | 18篇 |
专业分类
各国政治 | 53篇 |
工人农民 | 37篇 |
世界政治 | 71篇 |
外交国际关系 | 39篇 |
法律 | 334篇 |
中国政治 | 6篇 |
政治理论 | 175篇 |
综合类 | 28篇 |
出版年
2023年 | 9篇 |
2021年 | 9篇 |
2020年 | 10篇 |
2019年 | 10篇 |
2018年 | 18篇 |
2017年 | 21篇 |
2016年 | 21篇 |
2015年 | 20篇 |
2014年 | 28篇 |
2013年 | 101篇 |
2012年 | 13篇 |
2011年 | 28篇 |
2010年 | 20篇 |
2009年 | 16篇 |
2008年 | 26篇 |
2007年 | 29篇 |
2006年 | 34篇 |
2005年 | 29篇 |
2004年 | 17篇 |
2003年 | 15篇 |
2002年 | 25篇 |
2001年 | 17篇 |
2000年 | 14篇 |
1999年 | 9篇 |
1998年 | 10篇 |
1997年 | 4篇 |
1996年 | 9篇 |
1995年 | 6篇 |
1994年 | 7篇 |
1993年 | 11篇 |
1992年 | 6篇 |
1991年 | 12篇 |
1990年 | 12篇 |
1989年 | 12篇 |
1988年 | 6篇 |
1987年 | 7篇 |
1986年 | 4篇 |
1985年 | 11篇 |
1984年 | 4篇 |
1983年 | 12篇 |
1982年 | 7篇 |
1981年 | 8篇 |
1980年 | 6篇 |
1979年 | 6篇 |
1978年 | 7篇 |
1977年 | 6篇 |
1976年 | 5篇 |
1973年 | 3篇 |
1971年 | 3篇 |
1969年 | 6篇 |
排序方式: 共有743条查询结果,搜索用时 0 毫秒
31.
32.
The conflicting outcome of the electoral and popular votes inthe 2000 presidential election provoked calls to abolish oralter the electoral college. One prominent criticism is thatthe institution distorts election outcomes by providing disproportionateinfluence to small states. If each state receives a number ofpresidential electors equal to that states' number of membersin the U.S. House of Representatives plus the two senators,then the "federalism bonus" represents the two electoral collegevotes that correspond to the position of each state as an equalentity in the Senate. This research examines how the "federalismbonus" influences presidential selection by addressing threequestions. First, why did the framers include a federal componentin the electoral college? Second, under what circumstances hasthe "federalism bonus" played a role in presidential selection?Third, how would the various alternatives for reform affectthe federal component of the electoral college, and what isthe likelihood of adoption for each? 相似文献
33.
Comparing skeletal structures between antemortem and postmortem chest radiographs is widely used by forensic specialists from many disciplines to positively identify unknown decedents. However, validity assessments of this method have been fairly limited. This study had three objectives: 1) to quantify the reliability of ante- and postmortem chest radiograph comparison for decedent identification; 2) to identify useful radiologic features supporting decedent identification; and 3) to recognize sources of error in decedent identification related to use of comparative radiographs. A forensic pathologist, a forensic anthropologist, and two radiologists participated in the study. Our results showed that chest radiograph comparisons proved reliable, if basic decedent information was provided, and antemortem and postmortem radiographs were adequately positioned and exposed. A "morphological approach" using normal anatomical structures for comparison may provide the most efficient method for accurate identification. 相似文献
34.
Kent E. Calder 《East Asia》2006,23(3):49-66
Already the world’s second largest energy consumer, China has accounted for more than a third of the increase in global oil
demand since 2000. Due to infrastructural bottlenecks as well as supply shortages, intensified by sustained growth, the PRC
is likely to become an increasingly important factor in global oil and gas markets, and to pursue an increasingly active energy
diplomacy. Reducing energy vulnerability will be a key imperative. The PRC is striving to reduce its energy vulnerability
by: (1) promoting energy efficiency; (2) diversifying away from its heavy reliance on coal and oil, toward nuclear power and
natural gas; (3) improving domestic energy infrastructure; (4) promoting national energy champions; (5) deepening reliance
on congenial nations; and (6) reducing reliance on sea lanes dominated by the U.S. Navy. Kazakhstan, Iran, Russia, Venezuela,
Australia, and African energy producers are special priority targets of its energy diplomacy, which is likely to become more
salient in China's overall foreign policy in coming years. 相似文献
35.
36.
37.
Efficient capillary electrophoretic STR analysis requires rapid, reproducible and robust separation of DNA fragments with reasonable capillary longevity--this is currently accomplished using proprietary commercial polymeric sieving matrices specifically developed for this separation. These matrices, while effective, are costly and do not provide adequate resolution of STR DNA fragments in capillaries with shorter effective separation lengths, increasing the time required to accomplish the separation and minimizing the potential extrapolation to other miniaturized platforms. As the forensic community looks toward next generation microchip technology as a means of processing casework more rapidly, new sieving polymers need to be evaluated for utilization in this platform. The research presented here describes the assessment of commercially-available polymeric sieving matrices for STR analysis, with consideration given to feasibility of incorporation into a microdevice. Polymer composition, molecular weight, and concentration were evaluated, along with an assessment of the effects of buffer composition, separation temperature, and capillary length. These variables were evaluated individually or collectively on the ability to resolve STR DNA fragments and the reproducibility of the separations and the results compared to a proprietary commercial product. A 600,000 Da MW poly(ethylene oxide) (PEO) solution at a 3% (w/v) concentration was determined to be the most suitable matrix for these separations. This polymer, in coated capillaries, provided highly robust and reproducible separations, with near baseline resolution of fragments having single base differences. Reductions in the temperature of the separation, from 60 degrees C to 40 degrees C, and the urea concentration of the buffer, from 7 M to 3.5 M, provided increased longevity of the PEO polymer for repeated separations. Comparison of this polymer with currently specified commercial products used for STR analysis showed that the optimized PEO matrix provided superior separations under all conditions tested. In addition, PEO could be utilized in shorter capillary systems, with a concurrent decrease in analysis time, highlighting its potential for use in shortened capillary or microdevice systems. 相似文献
38.
Eighteen external quality assessment (proficiency testing) samples were prepared from client specimens collected with the Intercept oral fluid collection device and by spiking drug-free oral fluid. Samples were circulated in pairs at quarterly intervals to 13 UK and USA based laboratories for analysis by a panel of OraSure micro-plate Intercept enzyme immunoassay kits and hyphenated mass spectrophotometric techniques. During the survey, there was a single case of non-specificity in a false report for methadone. The major errors were of lack of sensitivity relative to the concentration thresholds specified for the immunoassays. The sensitivity for overall "present"/"not found" reports calculated as true positives/(true positives+false negatives) were for the amphetamine specific assay 50%, methyl-amphetamines 93%, barbiturates 64%, cannabinoids 73%, cocaine and metabolites 100%, benzodiazepines 69%, methadone 95%, opiates 79% (opiates excluding oxycodone 93%), phencyclidine 93% and human gamma-globulin 97%. A small number of the sensitivity errors were attributable to errors in chromatographic confirmation techniques. 相似文献
39.
V. Seymour Wilson 《Canadian public administration. Administration publique du Canada》1983,26(3):447-461
Book reviewed in this article: My Life and Work, A Happy Partnership: Memoirs of J. A. Corry. A Man of Influence: Norman A. Robertson and Canadian Statecraft, 1929–1968. The Ottawa Men: The Civil Service Mandarins 1935–1957. 相似文献
40.