全文获取类型
收费全文 | 288篇 |
免费 | 27篇 |
专业分类
各国政治 | 1篇 |
工人农民 | 2篇 |
世界政治 | 2篇 |
外交国际关系 | 2篇 |
法律 | 268篇 |
中国政治 | 4篇 |
政治理论 | 1篇 |
综合类 | 35篇 |
出版年
2023年 | 6篇 |
2022年 | 7篇 |
2021年 | 10篇 |
2020年 | 9篇 |
2019年 | 9篇 |
2018年 | 7篇 |
2017年 | 8篇 |
2016年 | 13篇 |
2015年 | 16篇 |
2014年 | 18篇 |
2013年 | 24篇 |
2012年 | 21篇 |
2011年 | 23篇 |
2010年 | 15篇 |
2009年 | 30篇 |
2008年 | 19篇 |
2007年 | 14篇 |
2006年 | 11篇 |
2005年 | 8篇 |
2004年 | 6篇 |
2003年 | 7篇 |
2002年 | 3篇 |
2001年 | 8篇 |
2000年 | 9篇 |
1998年 | 5篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1984年 | 1篇 |
排序方式: 共有315条查询结果,搜索用时 46 毫秒
101.
Shakhawan K. Mawlood M.S. Majid Alrowaithi Ph.D. Nigel Watson Ph.D. 《Journal of forensic sciences》2015,60(3):686-689
This study compares two novel swabs (forensiX) with a standard cotton swab (EUROTUBE) for the collection of saliva stains on glass slide for STR analysis. ForensiX collection tubes are a standard cotton swab in an “active drying” tube, where swab sample is soon dried by its innovative tube surface of the wall. The other is forensiX Nylon Flocked Swab. The study is two phases: The first “phase” assesses swab types regarding to retrieve ability of saliva. The second “phase” compares the drying ability of each swab to assess how crime samples would fare when left in storage. The main result showed that “active drying” is effective to store swabbed sample. The forensiX swabs generally are effective for higher (twofold to fourfold) DNA yield compared to delta lab swab (around 750 pg and 250 pg from 0.5 μL of saliva), respectively. These findings demonstrate the importance of drying performance in the preservation of DNA and swab selection. 相似文献
102.
Assessing the Utility of Soil DNA Extraction Kits for Increasing DNA Yields and Eliminating PCR Inhibitors from Buried Skeletal Remains 下载免费PDF全文
DNA identification of human remains is often necessary when decedents are skeletonized; however, poor DNA recovery and polymerase chain reaction (PCR) inhibition are frequently encountered, a situation exacerbated by burial. In this research, the utility of integrating soil DNA isolation kits into buried skeletal DNA analysis was evaluated and compared to a standard human DNA extraction kit and organic extraction. The soil kits successfully extracted skeletal DNA at quantities similar to standard methods, although the two kits tested, which differ mechanistically, were not equivalent. Further, the PCR inhibitors calcium and humic acid were effectively removed using the soil kits, whereas collagen was less so. Finally, concordant control region sequences were obtained from human skeletal remains using all four methods. Based on these comparisons, soil DNA isolation kits, which quickened the extraction process, proved to be a viable extraction technique for skeletal remains that resulted in positive identification of a decedent. 相似文献
103.
The successful extraction of DNA from historical or ancient animal bone is important for the analysis of discriminating genetic markers. Methods used currently rely on the digestion of bone with EDTA and proteinase K, followed by purification with phenol/chloroform and silica bed binding. We have developed a simple concentrated hydrochloric acid-based method that precludes the use of phenol/chloroform purification and can lead to a several-fold increase in DNA yield when compared to other commonly used methods. Concentrated hydrochloric acid was shown to dissolve most of the undigested bone and allowed the efficient recovery of DNA fragments <100 bases in length. This method should prove useful for the recovery of DNAs from highly degraded animal bone, such as that found in historical or ancient samples. 相似文献
104.
目的:研究血康胶囊提取工艺。方法:采用正交试验法进行优选,以TLCS法测定人参皂苷Rg1的含量。结果:提取交数、乙醇浓度对人参皂苷Rg1提取率及干膏率有显性影响。结论:最佳提取工艺为500ml/L乙醇回汉提取2次,溶剂用量依次为6,5倍,提取时间为1.5,1.5h。 相似文献
105.
106.
随着数据挖掘应用的深入,非结构化和半结构化数据的挖掘,将成为下一个数据挖掘应用的热点。文本挖掘是一种典型的非结构化数据挖掘,而Web挖掘则是典型的半结构化数据挖掘。所以将信息处理技术中的汉语分词、信息抽取、语义分析等技术应用到Web挖掘研究技术发展的必然趋势。本文应对Web挖掘的特点,将运用数据抽取进行数据结构转换并把语义分析技术应用到数据抽取的过程中的思想,使数据提取更加准确。 相似文献
107.
108.
目的:提取并测定芦根中甾族化合物的成分和相对含量。方法:采用气相色谱.飞行时间质谱法进行测定分析。结果:芦根提取物中含有4种甾体化合物。结论:该鉴定方法对药物成分的结构分析和临床用药具有指导意义。 相似文献
109.
110.
目的对三种不同前处理方法提取的牙齿DNA浓度进行比较,建立一种操作简便、经济适用、浓度较高的牙齿DNA提取的前处理方法。方法选择源自7具尸体的共21颗磨牙,每具尸体的3颗磨牙随机按牙屑法、球磨法、液氮研磨法进行前处理,并分别称取50 mg,采用Auto Mate Express~(TM)法医DNA提取系统提取DNA,对三种方法提取的DNA浓度和STR分型结果进行比较。结果牙屑法、球磨法和液氮研磨法提取的DNA质量浓度分别为0.055 6~1.989 1、0.036 6~1.175 6和0.037 8~1.249 0 ng/μL,牙屑法提取的DNA质量浓度较高(P0.05),且STR分型成功率高。结论牙屑法结合Auto Mate Express~(TM)法医DNA提取系统是提取牙齿DNA的一种切实可行的方法,可应用于法医学鉴定实践中。 相似文献