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   336篇
  免费   20篇
各国政治   9篇
工人农民   50篇
世界政治   12篇
外交国际关系   10篇
法律   211篇
中国政治   8篇
政治理论   54篇
综合类   2篇
  2023年   4篇
  2022年   4篇
  2021年   6篇
  2020年   9篇
  2019年   22篇
  2018年   24篇
  2017年   12篇
  2016年   22篇
  2015年   14篇
  2014年   16篇
  2013年   43篇
  2012年   20篇
  2011年   18篇
  2010年   11篇
  2009年   10篇
  2008年   13篇
  2007年   20篇
  2006年   19篇
  2005年   18篇
  2004年   14篇
  2003年   10篇
  2002年   8篇
  2001年   4篇
  2000年   1篇
  1998年   1篇
  1997年   1篇
  1996年   2篇
  1995年   1篇
  1993年   1篇
  1992年   1篇
  1991年   1篇
  1989年   1篇
  1988年   1篇
  1987年   1篇
  1986年   1篇
  1982年   1篇
  1974年   1篇
排序方式: 共有356条查询结果,搜索用时 31 毫秒
51.
Abstract: The University of Mississippi has a contract with the National Institute on Drug Abuse (NIDA) to carry out a variety of research activities dealing with cannabis, including the Potency Monitoring (PM) program, which provides analytical potency data on cannabis preparations confiscated in the United States. This report provides data on 46,211 samples seized and analyzed by gas chromatography‐flame ionization detection (GC‐FID) during 1993–2008. The data showed an upward trend in the mean Δ9‐tetrahydrocannabinol (Δ9‐THC) content of all confiscated cannabis preparations, which increased from 3.4% in 1993 to 8.8% in 2008. Hashish potencies did not increase consistently during this period; however, the mean yearly potency varied from 2.5–9.2% (1993–2003) to 12.0–29.3% (2004–2008). Hash oil potencies also varied considerably during this period (16.8 ± 16.3%). The increase in cannabis preparation potency is mainly due to the increase in the potency of nondomestic versus domestic samples.  相似文献   
52.
The plant Catha edulis, known more commonly as khat, has been consumed for centuries for its stimulatory effects, especially by people living in East Africa. As people from Somalia, Ethiopia and other East African countries have migrated to Australia, they have brought with them the practice of chewing khat. This article examines the claims made about the effects of khat on health and wellbeing and explores the approaches to the regulation of khat in Australia and overseas. The article concludes with a discussion of some of the concerns associated with current regulatory approaches and makes some suggestions for reform.  相似文献   
53.
Economists, sociologists, and legal scholars agree that intellectual‐property law is fundamental to markets because legal control over copying motivates creative production. But in many markets, such as fashion and databases, there is little or no intellectual‐property protection, yet producers still create innovative products and earn profits. Research on such “negative spaces” in intellectual‐property law reveals that social norms can constrain copying and support creative production. This insight guided our analysis of markets for American literature before the Civil War, in both magazines (a negative space, where intellectual‐property law did not apply) and books (a positive space, where intellectual‐property law did apply). We observed similar understandings of authors and similar commercial practices in both spaces because many authors published the same work in both spaces. Based on these observations, we propose that cultural elements that develop in positive spaces may spill over to related negative spaces, inducing changes in buyers' and sellers' behavior in negative spaces. Our historical approach also revealed nuances—shades of gray—beyond the sharp distinction typically drawn between negative and positive spaces. In the 1850s, a few large‐circulation magazine publishers began to claim copyright, but many still allowed reprinting and none litigated to protect copyright.  相似文献   
54.
When faced with commingled remains, it might be assumed that a more “masculine” pelvis is associated with a more “masculine” cranium, but this relationship has not been specifically tested. This study uses geometric morphometric analyses of pelvic and cranial landmarks to assess whether there is an intra‐individual relationship between the degrees of sexual expression in these two skeletal regions. Principal component and discriminant function scores were used to assess sexual dimorphism in 113 U.S. Black individuals. Correlation values and partial least squares regression (PLS) were used to evaluate intra‐individual relationships. Results indicate that the os coxae is more sexually dimorphic than the cranium, with element shape being more sexually dimorphic than size. PLS and correlation results suggest no significant intra‐individual relationship between pelvic and cranial sexual size or shape expression. Thus, in commingled situations, associations between these skeletal elements cannot be inferred based on degree of “masculinity.”  相似文献   
55.
Langley et al. (2017) developed a sex estimation decision tree utilizing two traditional cranial traits (glabella and mastoid) and a new trait: zygomatic extension. This study aimed to test the reliability of their zygomatic extension scoring method and validate their sex estimation method. Ordinal score data were collected from 281 male and female U.S. White and Black individuals. The five traditional cranial traits were collected from physical specimens, while zygomatic extension was scored from 3D cranial models. Intra‐ and interobserver analyses carried out on a subsample of 30 individuals indicate good agreement between zygomatic scores. The decision tree correctly sexed 71.5% of the sample, but a strong sex bias (94.2% correct for females, 49.3% correct for males) severely limits the utility of this method. The Walker (2008) and Stevenson et al. (2009) methods produced higher accuracy rates (80.8% and 82.6%, respectively), although these methods also produced sex and ancestry biases.  相似文献   
56.
There has naturally been a good deal of discussion of the forthcoming General Data Protection Regulation. One issue of interest to all data controllers, and of particular concern for researchers, is whether the GDPR expands the scope of personal data through the introduction of the term ‘pseudonymisation’ in Article 4(5). If all data which have been ‘pseudonymised’ in the conventional sense of the word (e.g. key-coded) are to be treated as personal data, this would have serious implications for research. Administrative data research, which is carried out on data routinely collected and held by public authorities, would be particularly affected as the sharing of de-identified data could constitute the unconsented disclosure of identifiable information.Instead, however, we argue that the definition of pseudonymisation in Article 4(5) GDPR will not expand the category of personal data, and that there is no intention that it should do so. The definition of pseudonymisation under the GDPR is not intended to determine whether data are personal data; indeed it is clear that all data falling within this definition are personal data. Rather, it is Recital 26 and its requirement of a ‘means reasonably likely to be used’ which remains the relevant test as to whether data are personal. This leaves open the possibility that data which have been ‘pseudonymised’ in the conventional sense of key-coding can still be rendered anonymous. There may also be circumstances in which data which have undergone pseudonymisation within one organisation could be anonymous for a third party. We explain how, with reference to the data environment factors as set out in the UK Anonymisation Network's Anonymisation Decision-Making Framework.  相似文献   
57.
Abstract

‘Tied’ or ‘in-kind’ international food aid has been criticised as an implicit form of export subsidy that governments use to circumvent export subsidy restrictions. In addition to displacing agricultural exports, food aid is less efficient than untied aid and depresses local agricultural production in recipient countries. I argue that tied food aid is not protected by the Uruguay Round Agreement on Agriculture and could consequently be challenged under the World Trade Organization's dispute settlement mechanism as a prohibited or actionable subsidy contrary to the Subsidies and Countervailing Measures (scm) Agreement. As the USA is both the largest donor of international food aid and most consistently ties its food aid to domestic agricultural producers, this paper focuses on US policy to describe the challenge that might be advanced under the scm Agreement.  相似文献   
58.
59.
Abstract

Participants attempted to select previously studied faces from lineups that were administered either sequentially (test faces presented one at a time) or simultaneously (test faces presented altogether). Target discriminability was manipulated by varying the number of facial features that could be used to distinguish the study face from the other test faces (foils) or by varying study face exposure duration. In addition, decision criterion level was manipulated via an instruction manipulation. Results indicated that sequential participants adopted a stricter decision standard under high criterion instructions compared to simultaneous participants. Under liberal criterion setting instructions, the rate at which the target was selected was comparable across lineup procedures. Target discriminability affected target selections to a greater extent in simultaneous compared to sequential lineups. We discuss the applied implications that these findings have regarding correct identifications from lineups.  相似文献   
60.
Abstract

Much of what is known about sexual offenders is based on correctional samples and then applied across settings based on the assumption that this group is homogeneous. In this study, 149 files were compared, including 108 cases from the forensic mental health system (FMH) and 41 cases from the correctional system (COR). Although many similarities were observed between the FMH and COR groups, the results also revealed important differences. The FMH group was characterised by more frequent hospitalisations, higher rates of major mental illness and single status. The COR group was characterised by a history of physical and sexual abuse, family history of addictions, more intrusive sexual offences and higher rates of offending. These results highlight different profiles for sexual offenders in forensic mental health and correctional settings and challenge us to consider the implications for assessment, treatment and risk management of this unique group of sexual offenders.  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