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   5366篇
  免费   317篇
各国政治   67篇
工人农民   73篇
世界政治   105篇
外交国际关系   278篇
法律   3465篇
中国共产党   41篇
中国政治   421篇
政治理论   410篇
综合类   823篇
  2024年   9篇
  2023年   123篇
  2022年   133篇
  2021年   160篇
  2020年   224篇
  2019年   175篇
  2018年   173篇
  2017年   208篇
  2016年   189篇
  2015年   123篇
  2014年   271篇
  2013年   414篇
  2012年   308篇
  2011年   333篇
  2010年   233篇
  2009年   315篇
  2008年   400篇
  2007年   355篇
  2006年   291篇
  2005年   273篇
  2004年   236篇
  2003年   186篇
  2002年   151篇
  2001年   107篇
  2000年   81篇
  1999年   51篇
  1998年   23篇
  1997年   23篇
  1996年   17篇
  1995年   25篇
  1994年   6篇
  1993年   6篇
  1992年   8篇
  1991年   5篇
  1990年   4篇
  1989年   6篇
  1988年   5篇
  1987年   8篇
  1986年   10篇
  1985年   3篇
  1984年   7篇
  1983年   4篇
  1982年   1篇
排序方式: 共有5683条查询结果,搜索用时 781 毫秒
1.
Cyanide is a highly toxic agent that has been frequently used for suicide in South Korea. It is also used in various industrial fields, such as metal plating, in which many accidental cyanide intoxications have occurred. To overcome the disadvantages of conventional cyanide analysis methods, a simple and fast method for the analysis of cyanide in whole blood using ion chromatography (IC) with amperometric detection was developed in this study. Whole blood samples were deproteinized, diluted, and analyzed using an IC–amperometric detection system. The limits of detection and quantitation were 0.1 and 0.2 mg/L, respectively. The method showed good linearity in the range of 0.2 to 50 mg/L with R2 > 0.99. The intra- and inter-assay precision and accuracy values were <10%. The established method was successfully applied to analyze whole blood samples from three cyanide intoxication cases.  相似文献   
2.
社会中层出不穷的"闹大"是公共治理状况的一面"镜子",也是转型时期政策议程建构的重要路径。本文采用清晰集定性比较分析(csQCA),对2003-2019年发生的40个"闹大"案例进行比较研究。研究结果表明,上级(层)政府支持是"闹大"成功的必要条件。推动"闹大"成功的充分条件组合共有八种,可具体归纳为制度框架使用模式、集体施压模式、专家引导模式和暴力强推模式等四种解释模型。公民"闹大"成功是多个条件组合的结果,在核心条件发挥基础作用的前提下,适当的辅助条件更容易触发政策议程,推动问题解决。文章为公民"闹大"的行动逻辑提供了新的因果解释机制,也为理解形形色色的"闹大"现象提供了新的理论工具。  相似文献   
3.
Semaan et al. (J Forensic Res, 2020, 11, 453) discuss a mock case “where eight different individuals [P1 through P8] could not be excluded in a mixed DNA analysis. Even though … expert DNA mixture analysis software was used.” Two of these are the true donors. The LRs reported are incorrect due to the incorrect entry of propositions into LRmix Studio. This forced the software to account for most of the alleles as drop-in, resulting in LRs 60–70 orders of magnitude larger than expected. P1, P2, P4, P5, and P8 can be manually excluded using peak heights. This has relevance when using LRmix which does not use peak heights. We extend the work using the same two reference genotypes who were the true contributors as Semaan et al. (J Forensic Res, 2020, 11, 453). We simulate three two-donor mixtures with peak heights using these two genotypes and analyze using STRmix?. For the simulated 1:1 mixture, one of the non-donors’ LRs supported him being a contributor when no conditioning was used. When considered in combination with any other potential donors (i.e., with conditioning), this non-donor was correctly eliminated. For the 3:1 mixture, all results correctly supported that the non-donors were not contributors. The low-template 4:1 mixture LRs with no conditioning showed support for all eight profiles as donors. However, the results from pair-wise conditioning showed that only the two ground truth donors had LRs supporting that they were contributors to the mixture. We recommend the use of peak heights and conditioning profiles, as this allows better sensitivity and specificity even when the persons share many alleles.  相似文献   
4.
Often, criminal acts involving a vehicle are caught on digital video surveillance systems. While potentially useful for an investigation, the recording conditions are typically less than optimal for the extraction of key information for the identification of the perpetrator, such as a license plate. Providing the make, model and year of a questioned vehicle is a common request for examiners, to narrow the field of potential suspect vehicles. This study seeks to compare the performance of a nonpeer-reviewed make, model, and year determination between two separate groups, specifically, trained forensic image examiners and nontrained individuals. Results show that even with varied image capture conditions and quality, the trained forensic image examiners more correctly and completely identified the test group of questioned vehicles make, model, and year.  相似文献   
5.
视频侦查已成为公安机关重要的刑侦基础性工作。目前省、市、县、所四级公安视频侦查体系基本建成,而作为基层一线的“所级”视频侦查体系,实践中没有受到足够的重视。应强化派出所层级的视频侦查体系建设,同时,合理协调全社会视频监控系统建设的系统推进,以提升视频侦查工作实战效能。  相似文献   
6.
In response to research demonstrating that irrelevant contextual information can bias forensic science analyses, authorities have increasingly urged laboratories to limit analysts' access to irrelevant and potentially biasing information (Dror and Cole (2010) [3]; National Academy of Sciences (2009) [18]; President's Council of Advisors on Science and Technology (2016) [22]; UK Forensic Science Regulator (2015) [26]). However, a great challenge in implementing this reform is determining which information is task-relevant and which is task-irrelevant. In the current study, we surveyed 183 forensic analysts to examine what they consider relevant versus irrelevant in their forensic analyses. Results revealed that analysts generally do not regard information regarding the suspect or victim as essential to their analytic tasks. However, there was significant variability among analysts within and between disciplines. Findings suggest that forensic science disciplines need to agree on what they regard as task-relevant before context management procedures can be properly implemented. The lack of consensus about what is relevant information not only leaves room for biasing information, but also reveals foundational gaps in what analysts consider crucial in forensic decision making.  相似文献   
7.
We present results of our study on the stability of 4-chloromethcathinone (4-CMC) in authentic postmortem peripheral blood and vitreous humor samples. The stability of 4-CMC was determined in postmortem blood samples (for a period of 90 days) and vitreous humor (30 days) at three different temperatures: −15°C, +4°C, and + 23°C. The analyses were carried out using ultra-high-performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry (UHPLC-QqQ-MS/MS). In both materials, the lowest 4-CMC stability was demonstrated at room temperature. The blood samples stored in a freezer (−15°C) showed stability for the entire study period (90 days), while in the case of the vitreous humor sample stored at the same temperature the concentration of the substance decreased by 53% after 30 days. The study carried out in authentic postmortem blood and vitreous humor samples confirms the previous reports of 4-CMC instability in biological material. Authors suggest that the biological material should be stored frozen until analyses are carried out as soon as possible after collection of the material.  相似文献   
8.
目的推导祖孙双单亲比对的匹配概率(PMGDS)公式,并以随机模拟法进行验证。方法首先,根据定义推导PMGDS的数学公式,依据此公式在19个基因座上计算PMGDS的数值。其次,以随机模拟法设计实验,在19个基因座上计算PMGDS的模拟值。最后,以模拟值对比公式值的方式,对公式进行实验验证。结果研究获得了PMGDS的数学公式,经模拟实验验证显示出良好的符合。结论祖孙双单亲比对的错判概率较低,具有很好的应用价值。  相似文献   
9.
法医工作者的职业暴露风险极大,案件现场及尸体上的有毒有害物质、高致病性微生物以及利器、骨折等因素均可能给法医带来身心伤害甚至生命危险。随着经济社会发展,法医的工作环境已经较过去显著改善,但是针对个人防护的重视程度仍需提高。近年来公共卫生事件频发,给法医职业防护带来新的挑战,迫切需要借鉴生物安全领域的先进技术和防护理念,以满足新形势下法医工作的需要。本指南立足当前法医职业防护的实际需求,从暴露风险、防护分级、应急处置等角度阐述,希望能为制定法医职业防护相关标准提供参考,以指导法医工作者开展个人防护工作,为提升法医职业化水平和身心健康提供帮助。  相似文献   
10.
赋值是智能政治学的重要研究课题,赋值研究是智能政治学的重要分析方法。人工智能赋值国家治理,从分析视角来看,表现为人工智能科学、人工智能技术、人工智能形态和人工智能体对国家治理的多重赋值和多源性影响作用。从分析维度来讲,表现为人工智能从赋益、赋义、赋能、赋权、赋则和赋责等多维度影响作用或赋值国家治理,甚至推动国家治理从"人工智能+国家治理"的形式赋值质变为"人机智能治理"的实质赋值。选择"赋值"术语工具、赋值理论和赋值分析方法,以分析研究人工智能影响作用国家治理,将有助于探明人工智能赋值国家治理的理论逻辑、历史逻辑和实践逻辑,从而推动智能政治学以及国家智能治理问题的理论研究和学术创新。  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