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   2168篇
  免费   134篇
各国政治   193篇
工人农民   143篇
世界政治   253篇
外交国际关系   165篇
法律   1149篇
中国政治   5篇
政治理论   378篇
综合类   16篇
  2024年   3篇
  2023年   28篇
  2022年   20篇
  2021年   37篇
  2020年   67篇
  2019年   98篇
  2018年   126篇
  2017年   154篇
  2016年   158篇
  2015年   97篇
  2014年   132篇
  2013年   373篇
  2012年   109篇
  2011年   96篇
  2010年   56篇
  2009年   52篇
  2008年   77篇
  2007年   91篇
  2006年   63篇
  2005年   60篇
  2004年   65篇
  2003年   46篇
  2002年   32篇
  2001年   37篇
  2000年   34篇
  1999年   20篇
  1998年   19篇
  1997年   11篇
  1996年   9篇
  1995年   16篇
  1994年   9篇
  1993年   10篇
  1992年   10篇
  1991年   8篇
  1990年   8篇
  1989年   6篇
  1988年   5篇
  1987年   7篇
  1985年   4篇
  1984年   6篇
  1983年   5篇
  1982年   3篇
  1979年   3篇
  1974年   4篇
  1973年   2篇
  1972年   4篇
  1971年   2篇
  1967年   6篇
  1966年   2篇
  1965年   2篇
排序方式: 共有2302条查询结果,搜索用时 46 毫秒
111.
112.
113.
Scanning electron microscopy analysis of experimental bone hacking trauma   总被引:2,自引:0,他引:2  
The authors report on their macro- and microscopy study of bone lesions made by a sharp force instrument (a single blade knife), and a sharp-blunt instrument classified as a chopping weapon (a hatchet). The aim of this work was to attempt to identify the instrument by analyzing the general class characteristics of the cuts. Each weapon was used on human bones. The results indicate that macroscopic analysis is more problematic. The microscopic analysis assessed that characteristics examined were effective in distinguishing sharp from sharp-blunt injury to the bone. The microscope facilitates analysis unachievable with macroscopic methods, some three-dimensional characteristics not visible to the naked eye being clearly defined with its use. Emphasis has been placed on the value of SEM as an anthropologist's tool in bone lesion injuries.  相似文献   
114.
115.
116.
Experimental data useful for the interpretation of paint evidence recovered during burglary cases were obtained. A population study was carried out on 41 blue crowbars seized on suspects in Switzerland and 37 blue paints traces found at burglary scenes. Paint traces were also searched on the blades of 207 crowbars seized by the police in Switzerland and 24 white traces were analysed: these paints were analysed using infrared spectroscopy (FTIR) in order to estimate relative frequencies of each paint type. Simulated contacts were carried out between crowbars and painted wood in order to study the phenomenon of transfer and to evaluate the amount of paint transferred: a total of 198 simulations were carried out including individual, successive and cross transfer. The paint properties such as the chemical composition and its age influenced the amount of paint transferred. Cross transfer from the tool paint to the wood and vice versa was regularly observed. Moreover, secondary transfer of paint coming from the preceding wooden surfaces was also systematically observed: this could establish links between several burglary scenes and a suspected tool. A scenario of a burglary case involving the cross transfer between tool and household paints is proposed as a numerical example: the evaluation of such case was formalised using likelihood ratios based on the experimental data obtained.  相似文献   
117.
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   
118.
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   
119.
The term corruptio appears in many languages, but behind it lie several contrasting strands of thought and language. Current political usages of corruptio--emphasizing bribery, which in turn is just one of several families of ideas to which the term has variously been attached--date from the late 18th or early 19th century, have been strongly influenced by Anglo-Saxon legal thought, and may be traced to Roman roots. But French lexicographers developed a richer and more diverse vocabulary to encompass the crimes of civil servants and judges in addition to those of the people who sought to influence them. Religion, and in particular offices within the Church, also strongly influenced the ideas and vocabulary of corruption. Ultimately, corruptio can be said to have Biblical origins and a core meaning centered around injustice. The complexity and richness of the idea of corruption, as viewed from that perspective, in often lost in the narrower and more technical usages that dominate contemporary debate and analysis.  相似文献   
120.
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