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   62篇
  免费   1篇
各国政治   5篇
工人农民   6篇
世界政治   4篇
外交国际关系   7篇
法律   28篇
中国政治   1篇
政治理论   12篇
  2023年   1篇
  2022年   1篇
  2021年   1篇
  2020年   6篇
  2018年   1篇
  2017年   2篇
  2016年   2篇
  2015年   2篇
  2014年   5篇
  2013年   8篇
  2012年   3篇
  2011年   2篇
  2010年   2篇
  2009年   1篇
  2008年   3篇
  2006年   2篇
  2005年   1篇
  2004年   3篇
  2003年   1篇
  2002年   1篇
  2001年   3篇
  1999年   1篇
  1996年   1篇
  1994年   1篇
  1991年   1篇
  1988年   1篇
  1985年   2篇
  1981年   1篇
  1980年   1篇
  1979年   1篇
  1976年   1篇
  1972年   1篇
排序方式: 共有63条查询结果,搜索用时 62 毫秒
1.
Do undocumented migrants underreport crimes to the police in order to avoid being deported? And do criminals exploit such vulnerability? We address these questions using victimization surveys and administrative data around the 1986 U.S. immigration amnesty. The amnesty allows us to solve two major identification issues that have plagued this literature: migrants’ legal status is endogenous and unobserved. The results show that the reporting rate of undocumented immigrants is 17 percent, which limits the immigrants’ ability to protect some of their fundamental human rights. However, right after the 1986 amnesty, which disproportionately legalized individuals of Hispanic origin, crime victims of Hispanic origin show enormous improvements in reporting behavior. The implied increase in the reporting rate by amnesty applicants is close to 20 percentage points.  相似文献   
2.
3.
A qualitative and quantitative analytical method was developed and validated for the determination of 49 licit and illicit drugs in oral fluid. Small oral fluid samples, volume 1mL, were collected from volunteers using a modified Omni-Sal device and the analytes were extracted from an oral fluid/buffer mixture using a single Bond Elut Certify solid phase extraction cartridge. Liquid chromatography-tandem mass spectrometry (LC-MS-MS) and gas chromatography-repetitive full scan mass spectrometry (GC-MS) were used in parallel to analyze the extracts for the targeted drugs. Extracts were analyzed by GC-MS in their underivatized form and as their pentafluoropropionyl derivatives. Deuterated internal standards were used for quantification of drugs of abuse by LC-MS-MS to minimize matrix effects. Methadone-d(9) and tumoxetine were used as the internal standards for quantification of non-derivatized and derivatized analytes respectively by GC-MS. Linearity was demonstrated over the range 5-200 ng/mL and limits of detection were less than 4 ng/mL for each drug analyzed. The method demonstrated acceptable recoveries for most of the analytes and good intra- and inter-day precision. Acquisition of data by repetitive full scan GC-MS allows the addition of further analytes to the target menu.  相似文献   
4.
Degradation of human DNA extracted from forensic stains is, in most cases, the result of a natural process due to the exposure of the stain samples to the environment. Experiences with degraded DNA from casework samples show that every sample may exhibit different properties in this respect, and that it is difficult to systematically assess the performance of routinely used typing systems for the analysis of degraded DNA samples. Using a batch of artificially degraded DNA with an average fragment size of approx. 200 bp a collaborative exercise was carried out among 38 forensic laboratories from 17 European countries. The results were assessed according to correct allele detection, peak height and balance as well as the occurrence of artefacts. A number of common problems were identified based on these results such as strong peak imbalance in heterozygous genotypes for the larger short tandem repeat (STR) fragments after increased PCR cycle numbers, artefact signals and allelic drop-out. Based on the observations, strategies are discussed to overcome these problems. The strategies include careful balancing of the amount of template DNA and the PCR cycle numbers, the reaction volume and the amount of Taq polymerase. Furthermore, a careful evaluation of the results of the fragment analysis and of automated allele calling is necessary to identify the correct alleles and avoid artefacts.  相似文献   
5.
This article considers two issues in relation to the increasing commercial exploitation of biological materials: first, whether the consent of the individual who is the source of biological material is needed for the material to be used commercially; and secondly, whether the source has any right to share in the profits. Whilst the legal requirement for consent to commercial use is uncertain, the overwhelming view from ethical statements suggests that such consent is appropriate. With regard to profit-sharing, source individuals have no legal right to share in the profits of commercial exploitation of their sample. However, there is support in some ethical statements for benefit-sharing with source individuals and their communities.  相似文献   
6.
7.
8.
9.
Traumatic vertebral artery dissection is not often seen by forensic pathologists, and cases investigated are scarce in the forensic literature. We present the case of a 40-year-old woman cyclist who was struck by a car while wearing a helmet, and was neurologically near normal immediately thereafter at Emergency. She presented 48 h later with acute right hemiparesis, decreasing level of consciousness, and unsteadiness. CT revealed massive cerebellar infarction. CT angiography was normal. The patient died in coma 7 days after injury and autopsy revealed bilateral edematous cerebellar infarction and bilateral vertebral artery dissection. Rotational neck injury and mural tear in the wall of the Atlantic parts of both vertebral arteries is suggested as the possible mechanism of the arterial injury. Head and neck injuries are reported as a precipitating cause of vertebral artery injury. The possible influence of trauma may be further underestimated if longer intervals between vessel dissection and ischemia occur. The current case illustrates that "talk-and-die" syndrome may be due to occult vertebral artery dissection, possibly bilateral. In forensic cases of delayed death after mild trauma to the head and neck, the vertebral arteries should be examined for the cause of death.  相似文献   
10.
The Journal of Technology Transfer - The paper investigates the relationship between public research and radical technological development. This study draws on the theory of recombinant innovation...  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