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   1236篇
  免费   70篇
各国政治   69篇
工人农民   57篇
世界政治   96篇
外交国际关系   103篇
法律   686篇
中国政治   10篇
政治理论   275篇
综合类   10篇
  2023年   19篇
  2022年   16篇
  2021年   15篇
  2020年   38篇
  2019年   48篇
  2018年   46篇
  2017年   60篇
  2016年   65篇
  2015年   39篇
  2014年   58篇
  2013年   170篇
  2012年   57篇
  2011年   41篇
  2010年   38篇
  2009年   41篇
  2008年   44篇
  2007年   65篇
  2006年   44篇
  2005年   57篇
  2004年   39篇
  2003年   35篇
  2002年   42篇
  2001年   19篇
  2000年   18篇
  1999年   23篇
  1998年   13篇
  1997年   9篇
  1996年   7篇
  1995年   14篇
  1994年   9篇
  1993年   3篇
  1992年   20篇
  1991年   7篇
  1990年   7篇
  1989年   10篇
  1988年   8篇
  1987年   6篇
  1986年   7篇
  1985年   6篇
  1984年   3篇
  1983年   7篇
  1982年   4篇
  1981年   2篇
  1980年   4篇
  1975年   3篇
  1973年   2篇
  1969年   3篇
  1966年   3篇
  1962年   1篇
  1955年   1篇
排序方式: 共有1306条查询结果,搜索用时 15 毫秒
141.
Farming and agribusiness could help employ and reintegrate conflict-affected youth in regions recovering from civil conflict. This study addresses the constraints for youth to engage themselves in agribusiness in the worst conflict-affected regions of northern Uganda. Specifically, it explores to what extent beekeeping and honey business offer viable socio-economic opportunities to formerly displaced youth. Using a value chain approach, the study draws on in-depth interviews with 23 (young) key stakeholders in the honey value chain, document analysis and focus group discussions. The results suggest that apiculture business can create employment for conflict-affected youth in northern Uganda due to the relatively low entry barriers, a young enthused vanguard and higher returns per unit input compared to other agricultural sectors in the region. However in order to succeed, this group requires support from community elders, government and business facilitators, because, due to their age and war background, these youngsters face the common constraints to farming and agribusiness, but at higher degrees of severity.  相似文献   
142.
143.
The case law of the CJEU on the economic free movement of people has departed from the traditional requirement that a nexus must be established between individual free movement and cross‐border economic activity, which has led to an extension of its scope. It is submitted that concerns with the protection of fundamental rights of European citizens are driving this process, and that the CJEU has sought to protect these fundamental rights through the market freedoms in two ways: by arguing that market freedoms are fundamental right themselves, and/or that European Citizenship has changed their normative underpinnings and status. This Article criticises both lines of argument, and defends a third: that the protection of these fundamental rights must be achieved at European level, if at all, through a conception of European Citizenship able to stand on its own.  相似文献   
144.
The analysis of amino acids present in fingerprints has been studied several times. In this paper, we report a method for the analysis of amino acids using an fluorenylmethyloxycarbonyl chloride‐derivatization for LC separation and MS detection. We have obtained good results with regard to the calibration curves and the limit of detection and LOQ for the target compounds. The extraction of the amino acids from the substrates used proved to be very efficient. Analysis of the derivatized amino acids enabled us to obtain full amino acid profiles for 20 donors. The intervariability is as expected rather large, with serine as the most abundant constituent, and when examining the total profile of the amino acids per donor, a characteristic pattern can be observed. Some amino acids were not detected in some donors, or fell out of the range of the calibration curve, where others showed a surprisingly high amount of material in the deposition analyses. Further investigations will have to address the intravariability of the amino acid profiles of the fingerprints from donors. By the development of the analytical method and the application to the analysis of fingerprints, we were able to gain insight in the variability of the constituents of fingerprints between the donors.  相似文献   
145.
The European Union (EU) has firmly set its stall out to protect individuals' data and privacy and has demonstrated this through the rejection of the old opt-out regime and the introduction of the new opt-in rules. These require businesses to obtain individual's prior and informed consent before their data are collected, stored and used for the purposes of online behavioural advertising (OBA). Individuals in the EU are afforded protection from the apparent dangers relating to data privacy and misuse that is associated with OBA, which is beyond the expectation of most Internet users. However, there are some criticisms levelled at the law that the EU has produced. Is simply gaining informed consent sufficient for protecting all types of information? Do certain types of information require a higher level of consent than others? Does the law fulfil its aim of protecting data subject's privacy and data? Is the current law restrictive to business? Do individuals know or care that their information is being collected for the purposes of targeted advertising and is there a better way to ensure that they do? Finally, will proposed new law to be found in the EU Data Protection Regulation solve any of these problems? This article will assess whether, as a policy decision, the EU's current approach has been too cautious in its attempts to protect individuals or restrict business.  相似文献   
146.
ABSTRACT

Previous research has predominantly measured populist attitudes as a one-dimensional concept, tapping into the distinction between the ordinary people and the culprit elites. With growing differentiation of populist viewpoints across the globe, this unidimensional approach may not reflect the multifaceted reality of the people’s populism. Most importantly, albeit paramount in right-wing populist rhetoric, exclusionist perceptions of others threatening the monocultural nation of the people are typically not captured in one-dimensional conceptualizations. To assess more precisely how populist attitudes are structured, we collected original survey data (N?=?809) among a representative sample of Dutch citizens. Using Multidimensional Scaling and Confirmatory Factor Analysis, we propose a two-dimensional structure: anti-establishment and exclusionism. This study further demonstrates how salient these different populist attitudes are among which voters.  相似文献   
147.
148.
The Belt and Road Initiative, proposed in 2013 by Chinese President Xi Jinping, improves cooperation among its participants in terms of both economic and cultural? devel-opment. Latin American countries started to join the initiative in 2017, and as of 2019, 19 of them signed related memoranda of understand-ing with China.  相似文献   
149.
The secondary dentin deposition that occurs after the tooth formation process results in a decrease in pulp cavity volume in adolescents and adults. The purpose of this critical review was to correlate pulpal and/or dental volume on cone-beam computed tomography (CBCT) with chronological age approximation. A subobjective was to investigate which methodology and CBCT technical parameters would be most appropriate to evaluate this correlation. This critical review followed the PRISMA guidelines, and it was conducted by a search through PubMed, Embase, SciELO, Scopus, Web of Science, Cochrane Library databases, as well as gray literature. Primary studies that used pulp volume, or pulp chamber to tooth volume ratio measured using CBCT were included. Seven hundred and eight indexed and 31 non-indexed records were identified. A qualitative analysis was performed including 25 selected studies with a total of 5100 individuals, age ranging from 8 to 87 years without sex predilection. The most used method was pulp volume/tooth volume. CBCT voxel size ranged between 0.09 and 0.5. Manual segmentation associated with threshold algorithms was used in most of the studies. Correlation between the pulp volume/tooth volume ratio was moderate: −0.66 for the upper central incisors, −0.59 for upper canines and −0.56 for lower canines. High heterogeneity was observed among the studies. It is concluded that pulp volume should be used with caution in age estimation. Evidence supports the preferable use of upper incisors with pulp volume/tooth volume ratio for age estimation. There is not enough evidence that voxel size interferes in age estimation by pulp volume.  相似文献   
150.
In the United States, the absence of federal funding and coordination for immigration legal services often means that local resources determine immigrants' access to justice. Many of these resources go toward supporting immigrants caught in the detention and deportation system. Yet local support is also critical for implementing federal benefits programs such as the 2012 Deferred Action for Childhood Arrivals (DACA) program. In this article, we draw on 146 interviews with representatives of legal services providers and their nonprofit collaborators in three immigrant-dense metropolitan areas—the Greater Houston Area, the New York City Metro Area, and the San Francisco Bay Area—to analyze the distinct, place-specific service and collaboration models that have emerged over the last decade to meet demand for DACA implementation support. Specifically, we examine how local context shapes the types of actors that immigrants can turn to for immigration legal services, and how they have coordinated on the ground in distinct ways during a time of increasing uncertainty.  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