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   373篇
  免费   39篇
各国政治   4篇
工人农民   3篇
世界政治   2篇
外交国际关系   20篇
法律   296篇
中国共产党   1篇
中国政治   14篇
政治理论   7篇
综合类   65篇
  2024年   6篇
  2023年   9篇
  2022年   3篇
  2021年   5篇
  2020年   10篇
  2019年   10篇
  2018年   9篇
  2017年   8篇
  2016年   15篇
  2015年   14篇
  2014年   22篇
  2013年   29篇
  2012年   16篇
  2011年   18篇
  2010年   22篇
  2009年   23篇
  2008年   22篇
  2007年   33篇
  2006年   36篇
  2005年   19篇
  2004年   7篇
  2003年   12篇
  2002年   10篇
  2001年   8篇
  2000年   9篇
  1999年   3篇
  1998年   6篇
  1997年   6篇
  1996年   4篇
  1995年   3篇
  1994年   6篇
  1992年   2篇
  1991年   4篇
  1985年   1篇
  1983年   2篇
排序方式: 共有412条查询结果,搜索用时 15 毫秒
151.
Zhao SM  Zhang SH  Li CT 《法医学杂志》2010,26(5):343-8, 356
目的采用插入/缺失(Insertion/Deletion,InDel)多态性遗传标记,建立一种可用于中国汉族、回族、维吾尔族、蒙古族、藏族5个主要民族法医DNA鉴定的多重PCR系统。方法采用人类基因组浏览器和dbSNP数据库筛选具有高度遗传多态性的人类常染色体InDel标记,采用Primer 3软件设计多重PCR引物,通过复合荧光标记系统建立多重PCR扩增体系,采用该体系对汉、回、维、蒙、藏5个民族进行多态性调查。结果成功建立了一个包含30个InDel位点和Amelogenin性别鉴定位点的复合荧光多重PCR扩增体系,命名为InDel_typer30。多态性调查显示这30个InDel位点在上述5个主要民族中均呈高度遗传多态性,平均期望杂合度分别为:0.464、0.460、0.453、0.466和0.469,平均个人识别率分别为:0.595、0.585、0.586、0.589和0.595。该系统在5个民族中的累积个人识别率(CDP)均达到0.999999999996以上。结论 InDel_typer30是一种适用于中国汉、回、维、蒙、藏5个主要民族的法医DNA鉴定系统。  相似文献   
152.
Wu HY  Wang KJ  Zhang L  Guo LW  Guo JN  Fan AY 《法医学杂志》2010,26(6):425-427
目的探讨小鼠在不同的死亡方式下肝组织管家基因甘油醛-3-磷酸脱氢酶(glyceraldehyde-3-phosphate dehydrogenase,GAPDH)mRNA降解与死亡时间(postmortem interval,PMI)的关系。方法将60只NIH小鼠分别采用窒息法和断颈法处死,分别置于10℃和25℃温控系统内,利用两步法RT-PCR技术和核酸蛋白测定仪检测小鼠肝组织中GAPDH mRNA在死后0~48h的降解情况。结果在10℃温控系统内的小鼠死后0~48h及25℃温控系统内的小鼠死后0~36h肝组织均可检测到GAPDH mRNA,且其扩增产物呈规律性下降趋势。结论小鼠死亡后肝组织GAPDH mRNA降解与PMI呈负相关,可为PMI推断提供一种新的观测指标。  相似文献   
153.
World leaders are beginning to look beyond temporary fixes to the challenge of securing the Internet. One possible solution may be an international arms control treaty for cyberspace. The 1997 Chemical Weapons Convention (CWC) provides national security planners with a useful model. CWC has been ratified by 98% of the world’s governments, and encompasses 95% of the world’s population. It compels signatories not to produce or to use chemical weapons (CW), and they must destroy existing CW stockpiles. As a means and method of war, CW have now almost completely lost their legitimacy. This article examines the aspects of CWC that could help to contain conflict in cyberspace. It also explores the characteristics of cyber warfare that seem to defy traditional threat mitigation.  相似文献   
154.
In this study, the stability and specificity of a counterfeit protection system (CPS) code were determined. This research involved an analysis of a counterfeit protection system code unit over time using the pattern location measurement method. We collected 379 sample sheets from 196 printers or photocopiers, covering 14 original brands, including 129 models. There was an interval of at least two months between the collections of samples from each machine. Four types of characteristics were established: CPS pattern unit, distance of the CPS unit, position of dots, size and shape of the dot. Except for the partial changes in the Xerox brand, no other brand exhibited changes over time. This implies that the CPS characteristics are stable. Meanwhile, no correlation was noted between the combinations of the characteristic systems in the collected samples, which implied strong specificity.  相似文献   
155.
Psilocybe cubensis, or “magic mushroom,” is the most common species of fungus with psychedelic characteristics. Two primer sets were designed to target Psilocybe DNA using web‐based software and NBCI gene sequences. DNA was extracted from eighteen samples, including twelve mushroom species, using the Qiagen DNeasy® Plant Mini Kit. The DNA was amplified by the polymerase chain reaction (PCR) using the primers and a master mix containing either a SYBR® Green I, Radiant? Green, or LCGreen Plus® intercalating dye; amplicon size was determined using agarose gel electrophoresis. The PCR assays were tested for amplifiability, specificity, reproducibility, robustness, sensitivity, and multiplexing with primers that target marijuana. The observed high resolution melt (HRM) temperatures for primer sets 1 and 7 were 78.85 ± 0.31°C and 73.22 ± 0.61°C, respectively, using SYBR® Green I dye and 81.67 ± 0.06°C and 76.04 ± 0.11°C, respectively, using Radiant? Green dye.  相似文献   
156.
Abstract:  The time required for short tandem repeat (STR) amplification is determined by the temperature ramp rates of the thermal cycler, the components of the reaction mix, and the properties of the reaction vessel. Multiplex amplifications in microfluidic biochip-based and conventional tube-based thermal cyclers have been demonstrated in 17.3 and 19 min, respectively. Optimized 28-cycle amplification protocols generated alleles with signal strengths above calling thresholds, heterozygous peak height ratios of greater than 0.65, and incomplete nontemplate nucleotide addition and stutter of less than 15%. Full CODIS-compatible profiles were generated using the Profiler Plus ID, COfiler and Identifiler primer sets. PCR performance over a wide range of DNA template levels from 0.006 to 4 ng was characterized by separation and detection on a microfluidic electrophoresis system, Genebench-FX. The fast multiplex PCR approach has the potential to reduce process time and cost for STR analysis and enables development of a fully integrated microfluidic forensic DNA analysis system.  相似文献   
157.
Abstract: A short tandem repeat multiplex assay has been successfully developed with 25 autosomal loci plus the sex‐typing locus amelogenin for a total of 26 amplified products in a single reaction. Primers for the loci were designed so that all of the amplicons present were distributed from 65 base pairs (bp) to less than 400 bp within a five‐dye chemistry design with the fifth dye reserved for the sizing standard. A multiplex design strategy was developed to overcome challenges encountered in creating this assay. The limits of the multiplex were tested, resulting in the successful amplification of a wide range of genomic DNA sample concentrations from 2 ng to as low as 100 pg with 30 cycles of PCR. The 26plex has the potential to benefit the forensic community for reference sample testing and complex relationship evaluation.  相似文献   
158.
Abstract: Literature regarding bone color is limited to determining location of primary and secondary dispositions. This research is the first to use bone color to interpret the sequence of events surrounding body disposition. Two scenarios were compared—bones buried and then exposed on the ground surface and bones exposed then buried. Forty juvenile pig humeri with minimal tissue were used in each scenario with an additional 20 controls to determine if decomposing tissue affects bone color. Munsell Color Charts were used to record bone color of surface and 2.5 cm cross‐sections. Results reveal five main surface colors attributed to soil, sun, hemolysis, decomposition, and fungi. Fungi on buried bones suggests prior surface exposure. Cross‐sections of strictly buried bones are identical to buried then exposed bone, stressing the importance of bone surface analysis. Cross‐sectioning may help verify remains have been exposed then buried. Decomposition of excess tissue creates minimal color staining.  相似文献   
159.
目的 调查中国武汉地区汉族人群STR基因座—D3S1 358、D1 3S31 7、D1 2S391基因频率分布和群体遗传数据。方法 从 2 0 8个汉族无关个体收集血液标本 ,应用PCR技术及聚丙烯酰胺凝胶垂直板电泳对D3S1 358、D1 3S31 7和D1 2S391基因座分型。结果 D3S1 358检出 7个等位基因和 4 1个基因型。三基因座基因型分布符合Hardy-Weinberg平衡。观察 2 31次减数分裂均未发现突变基因。另外 ,调查结果计算显示D3S1 358、D1 3S31 7和D1 2S391基因座的杂合度 (H)分别为 0 70 98、 0 80 56和 0 84 0 0 ;三个人识别能力 (DP)分别为 0 851 6、 0 9332和 0 952 3;非父排除率 ( pE)分别为 0 4 463、 0 60 1 6和 0 681 8。结论 D3S1 358、D1 3S31 7和D1 2S391基因座在群体遗传学研究和法医学亲子鉴定及个人识别中具有较高实用价值  相似文献   
160.
环介导等温扩增技术在畜牧兽医领域的应用   总被引:1,自引:0,他引:1  
介绍了环介导等温扩增技术的引物设计方法、扩增原理和结果判定方法,概述了该技术在动物病毒、细菌、真菌和寄生虫检测等兽医领域以及在动物胚胎性别鉴定和性别控制等畜牧领域的应用情况,旨在为该技术的深入研究和应用提供帮助.  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