全文获取类型
收费全文 | 494篇 |
免费 | 22篇 |
专业分类
各国政治 | 26篇 |
工人农民 | 19篇 |
世界政治 | 44篇 |
外交国际关系 | 35篇 |
法律 | 235篇 |
中国政治 | 2篇 |
政治理论 | 146篇 |
综合类 | 9篇 |
出版年
2022年 | 4篇 |
2021年 | 5篇 |
2020年 | 7篇 |
2019年 | 13篇 |
2018年 | 16篇 |
2017年 | 15篇 |
2016年 | 21篇 |
2015年 | 10篇 |
2014年 | 16篇 |
2013年 | 83篇 |
2012年 | 13篇 |
2011年 | 9篇 |
2010年 | 17篇 |
2009年 | 13篇 |
2008年 | 10篇 |
2007年 | 14篇 |
2006年 | 18篇 |
2005年 | 14篇 |
2004年 | 15篇 |
2003年 | 10篇 |
2002年 | 18篇 |
2001年 | 8篇 |
2000年 | 9篇 |
1999年 | 8篇 |
1998年 | 7篇 |
1997年 | 12篇 |
1996年 | 12篇 |
1995年 | 3篇 |
1994年 | 6篇 |
1993年 | 4篇 |
1992年 | 7篇 |
1991年 | 8篇 |
1990年 | 5篇 |
1989年 | 8篇 |
1988年 | 4篇 |
1986年 | 3篇 |
1985年 | 8篇 |
1984年 | 5篇 |
1983年 | 8篇 |
1982年 | 9篇 |
1981年 | 7篇 |
1979年 | 2篇 |
1978年 | 6篇 |
1976年 | 2篇 |
1975年 | 5篇 |
1974年 | 2篇 |
1973年 | 3篇 |
1972年 | 2篇 |
1970年 | 3篇 |
1968年 | 2篇 |
排序方式: 共有516条查询结果,搜索用时 0 毫秒
171.
172.
Campaigning in the British Electoral System Referendum of 2011 provoked much controversy. Accusations of negativity and dissemination of misinformation came from both sides. Using panel data spanning the crucial period of the campaign, this paper examines shifts in perceptions and intentions associated with information and opinion. First, it takes into account ‘baseline’ effects such as initial partisan cues. Then, in the context of criticism of the low quality information content of the campaign, it asks how much changes in the attitudes of respondents affected electoral system opinion, and the extent to which these changes reflected learning and the provision of information or misinformation. The roles of the Electoral Commission, television coverage, and newspapers are also examined. 相似文献
173.
Thomas Earl Porter 《Nationalities Papers》2013,41(2):455-460
Ferro, Nicholas, Nicholas II: The Last of the Tsars. New York and Oxford: Oxford University Press, 1993, 305 pp. Lieven, Dominic, Nicholas II: Emperor of all the Russias. London: John Murray, 1993, 292 pp. Radzinsky, Edvard, The Last Tsar: The Life and Death of Nicholas II New York: Doubleday, 1992, 462 pp. Verner, Andrew, The Crisis of Russian Autocracy: Nicholas II and the 1905 Revolution. Princeton: Princeton University Press, 1990, 372 pp. 相似文献
174.
175.
This article examines how communication patterns mediate the influences of values on political participation. We find that the positive effects of postmaterial values on participation are mediated through reading public affairs content in newspapers. In contrast, materialist values negatively affect participation through watching television entertainment. Interpersonal discussion in which disagreement occurs mediates both the positive effect of reading public affairs and the negative effect of materialism on political participation. We also provide what may be a better explanation of the influence of communication patterns on political participation by going beyond acquisition of factual political knowledge. We show that individuals' efforts to think about news and search for additional information and perspectives modify what people "get from" media. Reflecting about news and integrating information from various sources promote better understanding of the political world and may provide a stronger cognitive base for political participation than factual political knowledge. 相似文献
176.
Lauren C. Porter 《Law & social inquiry》2013,38(4):863-891
Largely absent from US criminal sentencing since the early 1800s, shame penalties have been staging a comeback. This revival has been met by a number of debates among legal scholars, one of which centers on the potential for such penalties to reduce crime. This study addresses this debate by investigating the impact of formal shaming on drunk driving and alcohol‐related traffic safety in Ohio. In accordance with the Traffic Law Reform Act of 2004, judges have since been mandated to issue “restricted plates” to certain first‐time and all repeat DUI offenders with limited driving privileges. Results indicate a curvilinear association between punishment levels and drunk driving. Increases in the certainty and visibility of plates are associated with decreases in suspension rates, but there is a point at which increasing the punishment level no longer retains its intended impact. In addition, levels of punishment are unrelated to alcohol‐related traffic safety. 相似文献
177.
In this work, a number of performance checks were carried out to evaluate the efficacy of commercial Y-short tandem repeats (Y-STR) kits for casework applications. The study evaluated the sensitivity, specificity and stability of the Y-STR markers used and the ability to obtain a male profile from postcoital samples taken at various time points after intercourse. All systems performed well with 1-3 ng of male DNA as recommended by the manufacturers. All systems gave full profiles at 100 pg of input DNA, which is within the realm of low copy number DNA analysis. Moreover all, except Y-Plex12, gave full profiles with 30-50 pg of male DNA. No increased performance was obtained with any of the systems by increasing the cycle number beyond that recommended by the various manufacturers. When up to 1 microg of female DNA was used (in the absence of male DNA) no female DNA cross reactivity was observed with the Y-Plex 12 and Y-Filer systems. PowerPlex Y produced female DNA derived products near the DYS438 and within the DYS392 loci at a rare allele position with high input DNA levels (300 ng and 1 microg, respectively). Male/female DNA admixture experiments indicated the particularly high specificity of the Y-Filer and PowerPlex Y systems under conditions of several thousand fold female DNA excess. All systems were able to detect the minor alleles in male/male DNA admixtures at a 1:5 dilution with the PowerPlex Y and Y-Filer being able to detect some minor alleles at 1:20. Species testing indicated some limited, minor cross reactivity of the commercial systems with some domestic male mammals although it is easily recognizable and would not pose any problems in casework analysis. As expected a significant number of cross-reacting products were obtained with nonhuman primate species. All Y-STR multiplex systems tested were able to produce complete Y-STR profiles from bloodstains and semen stains exposed up to 6 weeks when the samples were protected against precipitation and sunlight. However, exposure of the samples to precipitation either in the presence or absence of sunlight resulted in Y-STR profile loss over time, with total profile loss occurring with all systems after 3 weeks or more. Complete Y-STR profiles of the male donors up to 72 h postcoitus were obtained with all of the multiplex systems tested, except for Y-Plex12, which gave partial profiles. 相似文献
178.
Simplified low-copy-number DNA analysis by post-PCR purification 总被引:5,自引:0,他引:5
Frequently, evidentiary items contain an insufficient quantity of DNA to obtain complete or even partial DNA profiles using standard forensic gentotyping techniques. Such low-copy-number (LCN) samples are usually subjected to increased amplification cylces to obtain genetic data. In this study, a 28-cycle polymerase chain reaction (PCR) was used to evaluate various methods of post-PCR purification for their effects on the sensitivity of fluorophore-based allelic detection subsequent to capillary electrophoretic separation. The amplified product was purified using filtration, silica gel membrane, and enzyme mediated hydrolysis purification techniques and evaluated for their effect on fluorescent allelic signal intensity. A purification method was selected and its effect on fluorescent allelic signal intensity was compared with that of the unpurified PCR product. A method of post-PCR purification is described which increases the sensitivity of standard 28-cycle PCR such that profiles from LCN DNA templates (<100 pg DNA) can be obtained. Full DNA profiles were consistently obtained with as little as 20 pg template DNA without increased cycle number. In mock case type samples with dermal ridge fingerprints, genetic profiles were obtained by amplification with 28 cycles followed by post-PCR purification whereas no profiles were obtained without purification of the PCR product. Allele dropout, increased stutter, and sporadic contamination typical of LCN analysis were observed; however, no contamination was observed in negative amplification controls. Post-PCR purification of the PCR product can increase the sensitivity of capillary electrophoresis to such an extent that DNA profiles can be obtained from <100 pg of DNA using 28-cycle amplification. 相似文献
179.
180.
While forensic laboratories are coming under increasing pressure to provide meaningful estimates of measurement uncertainty, there has been little discussion of this topic in the literature. This article summarizes ten bases for estimating this parameter: (1) proficiency tests; (2) readability limits; (3) independent reference materials; (4) operational limits applied during calibration; (5) expert judgment; (6) precision control samples without (6) and with (7) contributions from extramural sources of error; (8) error budgets; (9) historical performance; and (10) ruggedness tests. Based on the assumptions underlying each approach, the forensic community will need to apply a variety of discipline-specific approaches to arrive at satisfactory estimates of measurement uncertainty. 相似文献