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   1036篇
  免费   53篇
各国政治   79篇
工人农民   61篇
世界政治   121篇
外交国际关系   55篇
法律   581篇
中国共产党   1篇
中国政治   4篇
政治理论   180篇
综合类   7篇
  2023年   12篇
  2022年   9篇
  2021年   22篇
  2020年   33篇
  2019年   32篇
  2018年   62篇
  2017年   70篇
  2016年   69篇
  2015年   43篇
  2014年   44篇
  2013年   137篇
  2012年   46篇
  2011年   31篇
  2010年   25篇
  2009年   22篇
  2008年   33篇
  2007年   43篇
  2006年   31篇
  2005年   36篇
  2004年   49篇
  2003年   27篇
  2002年   33篇
  2001年   32篇
  2000年   16篇
  1999年   11篇
  1997年   8篇
  1996年   5篇
  1993年   2篇
  1992年   5篇
  1991年   8篇
  1990年   7篇
  1989年   9篇
  1988年   6篇
  1987年   5篇
  1986年   2篇
  1985年   5篇
  1984年   3篇
  1983年   3篇
  1982年   2篇
  1980年   2篇
  1979年   3篇
  1977年   3篇
  1975年   2篇
  1973年   7篇
  1972年   6篇
  1971年   9篇
  1968年   2篇
  1967年   3篇
  1964年   2篇
  1963年   2篇
排序方式: 共有1089条查询结果,搜索用时 15 毫秒
61.
This article analyzes how market reform policies already in place affect social interests, and the feedback effects of those interests on reform processes. The variety of societal responses includes the creation of new societal organizations, reflecting the variable content and asymmetrical distribution of costs and benefits of the policies implemented. Because of this variety even in Peru, where the disorganizing effects of neoliberal reform appear to be strongest, it would seem that the societal impact of economic reform elsewhere in Latin America would also warrant more careful examination.  相似文献   
62.
63.
64.
65.
66.
67.
Nine Y-STR loci from the "minimal haplotype" included in Y-STR Haplotype Reference Databases (YHRD) together with eight additional Y-STRs (DYS437, DYS438, DYS439, DYS460, DYS461, GATA C4, GATA H4 and GATA A10) were analyzed in a sample of 101 males from Equatorial Guinea living in Madrid. Haplotype and allelic frequencies were calculated and genetic diversities were estimated for each genetic system as well as for the whole haplotype. An unexpected high frequency (6%) of intermediate alleles (13.2 and 14.2) was found in DYS385. For DYS19, two alleles were found in one sample. Another sample failed to amplify with DYS393 primers using either PowerPlex Y System (Promega Corporation) or the Y-PLEXtrade mark 12 (Reliagene, New Orleans, LA) commercial kits. Comparison between Equatorial Guinea and another African population (Mozambique; South East Coast) revealed a significant pairwise Phi(st) value between them (Phi(st)=0.03309; P=0.00000).  相似文献   
68.
The 11 Y-chromosomal short tandem repeats (STRs) included in the Promega Corporation PowerPlex Y System (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385, DYS437, DYS438 and DYS439) were typed in three ethnic groups ("Andalusians", Berber and Arab) and one cosmopolitan population (Tunis) from Tunisia, summing up 247 individuals, and 139 different haplotypes. Focusing the analysis on the seven Y-STRs of the YHRD Minimal Haplotype Core (DYS385 excepted), "Andalusians" showed no differences from the Cosmopolitan and the Arab samples previously published (our Arab sample presented an extremely low haplotype diversity), but were different from the Berbers. The Berbers from Tunisia were not different from those from Morocco.  相似文献   
69.
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   
70.
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   
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