首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   453篇
  免费   27篇
各国政治   49篇
工人农民   13篇
世界政治   48篇
外交国际关系   27篇
法律   249篇
中国政治   11篇
政治理论   82篇
综合类   1篇
  2023年   5篇
  2022年   2篇
  2021年   7篇
  2020年   19篇
  2019年   18篇
  2018年   15篇
  2017年   25篇
  2016年   26篇
  2015年   15篇
  2014年   25篇
  2013年   71篇
  2012年   20篇
  2011年   12篇
  2010年   14篇
  2009年   15篇
  2008年   14篇
  2007年   20篇
  2006年   19篇
  2005年   22篇
  2004年   18篇
  2003年   16篇
  2002年   14篇
  2001年   9篇
  2000年   10篇
  1999年   6篇
  1998年   2篇
  1997年   6篇
  1995年   2篇
  1993年   1篇
  1992年   2篇
  1991年   1篇
  1988年   1篇
  1987年   2篇
  1986年   3篇
  1985年   1篇
  1984年   1篇
  1983年   1篇
  1981年   2篇
  1980年   3篇
  1979年   4篇
  1978年   1篇
  1977年   2篇
  1974年   5篇
  1972年   1篇
  1966年   1篇
  1965年   1篇
排序方式: 共有480条查询结果,搜索用时 437 毫秒
1.
The optical and morphological properties of resveratrol were investigated. This nontoxic fluorescent natural material, emitting in the visible blue light, was used as an optical marker, enabling the enhancement of the image contrast coming from relief pictures marked on challenging surfaces. By applying appropriated imaging softwares, this marker was verified to be very useful in the latent fingerprint recognition deposited on different wood surface types, mainly those with high level of roughness, where conventional forensic materials do not allow effective fingerprint image visualization.  相似文献   
2.
The pandemic of Covid-19 has exposed the veins of inequality in Latin America. With a socioeconomic disaster looming, social emergency policies seemed inevitable. Yet while governments argue over the continuity of such policies and whether the fiscal rules in place should be respected, no sustainable response has come out. This essay problematises whether the pandemic could represent a critical juncture to forge ahead with political narratives that highlight tax exemptions and privileges enjoyed by the rich. We analyse the mitigation measures adopted by Argentina, Brazil, Chile and Uruguay and their repercussions on the debate surrounding progressive tax reforms to fund social schemes.  相似文献   
3.
4.
Allele frequencies, together with some parameters of forensic interest were estimated for nine STRs included in the AmpF/STR Profiler kit (CSF1PO, D3S1358, D5S818, D7S820, D13S317, FGA, TH01, TPOX and vWA) in a sample of 215 unrelated individuals from Cartagena (Colombia). For all loci, no significant deviations from Hardy-Weinberg equilibrium were observed. Comparative analysis results between our data and those from other Colombian and African population samples revealed significant differences, except with two Colombian Caribbean Coast sub-regions.  相似文献   
5.
Now that racism has been officially recognized in Brazil, and some universities have adopted affirmative-action admission policies, measures of the magnitude of racial inequality and analyses that identify the factors associated with changes in racial disparities over time assume particular relevance to the conduct of public debate. This study uses census data from 1950 to 2000 to estimate the probability of death in the early years of life, a robust indicator of the standard of living among the white and Afro-Brazilian populations. Associated estimates of the average number of years of life expectancy at birth show that the 6.6-year advantage that the white population enjoyed in the 1950s remained virtually unchanged throughout the second half of the twentieth century, despite the significant improvements that accrued to both racial groups. The application of multivariate techniques to samples selected from the 1960, 1980, and 2000 census enumerations further shows that, controlling for key determinants of child survival, the white mortality advantage persisted and even increased somewhat in 2000. The article discusses evidence of continued racial inequality during an era of deep transformation in social structure, with reference to the challenges of skin color classification in a multiracial society and the evolution of debates about color, class, and discrimination in Brazil.  相似文献   
6.
An analytical method using solid-phase extraction (SPE) and high-performance liquid chromatography–mass spectrometry (LC–MS) has been developed and validated for the confirmation of Δ9-tetrahydrocannabinol (THC) in oral fluid samples. Oral fluid was extracted using Bond Elut LRC-Certify solid-phase extraction columns (10 cm3, 300 mg) and elution performed with n-hexane/ethyl acetate. Quantitation made use of the selected ion-recording mode (SIR) using the most abundant characteristic ion [THC + H+], m/z 315.31 and the fragment ion, m/z 193.13 for confirmation, and m/z 318.00 for the protonated internal standard, [d3-THC + H+]. The method proved to be precise for THC, in terms of both intra-day and inter-day analyses, with coefficients of variation less than 10%, and the calculated extraction efficiencies for THC ranged from 76 to 83%. Calibration standards spiked with THC between 2 and 100 ng/mL showed a linear relationship (r2 = 0.999). The method presented was applied to the oral fluid samples taken from the volunteers during the largest music event in Portugal, named Rock in Rio-Lisboa. Oral fluid was collected from 40 persons by expectoration and with Salivette®. In 55% of the samples obtained by expectorating, THC was detected with concentration ranges from 1033 to 6552 ng/mL and in 45% of cases THC was detected at concentrations between 51 and 937 ng/mL. However, using Salivette® collection, 26 of the 40 cases had an undetectable THC.  相似文献   
7.
This paper seeks to examine the extent to which left-wing forces are making a comeback in Latin America and to draw out the political implications of their political ascendancy. It argues that while left-of-centre parties have developed a persuasive critique of the failures of liberal democracy and economic neoliberalism in the region, there is as yet no conceptual clarity or distinct policy initiatives materialising from the left's promises of deepening democracy and implementing an alternative economic model. When in power, left-of-centre parties have followed a strategy of 'bending and moulding' existing political institutions and the free-market economic model rather than attempting radical political and economic reforms. This paper concludes that left-of-centre parties are right in accepting that there is little room in the region for an anti-systemic model and that instead the emphasis should be placed on making states, markets and democracy work better to secure development, address social demands and attack the root causes of discrimination and inequality. But leaving behind old certainties and adapting to the new political and economic environment has come at the cost of a loss of intellectual confidence, ideological clarity and weakened identities.  相似文献   
8.
9.
The paper explores the aerial dimension of policing and surveillance. It does so by drawing upon select results from a large‐scale survey conducted in 2017 among professional (public and private) drone users in Switzerland. Focusing in particular on the police, the paper shows that the technology not only generates novel ways of looking down from above, but also of looking up from below, thus instilling a kind of air‐mindedness among the police. In making the airspace explicit as an object, and stake of imaginaries, concerns and practices, drones mediate novel ways of relating to the air, understanding it, approaching it and acting in relation to it.  相似文献   
10.
Economical liberalization, market globalization and soy expansion stimulated the advance of big transnational companies in the Southern Cone countries (Brazil, Argentina, Paraguay and Uruguay). Currently, the main corporations acting on the last links of the productive chain are ADM (Archer Daniels Midland), Bunge, Cargill and Dreyfus (the ABCD firms), global leaders in the soy trade. The objective of this contribution is to analyze the different strategies these companies articulate in the Southern Cone, and their dynamics in local space through market relations with local producers. The results show the rapid and intense process of denationalization of the firms in the soy productive chain as well as the high level of market internationalization and company concentration. In spite of this, this study shows that all transnational power of ABCD firms, which seems so abstract and intimidating when seen in the global scale, depends on its basis of the formation, maintenance and exploration of relations of proximity, trust and reciprocity with local actors (especially rural producers), including family friendship linkages.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号