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   879篇
  免费   40篇
各国政治   113篇
工人农民   71篇
世界政治   73篇
外交国际关系   60篇
法律   404篇
中国政治   65篇
政治理论   129篇
综合类   4篇
  2023年   9篇
  2022年   7篇
  2021年   23篇
  2020年   29篇
  2019年   32篇
  2018年   45篇
  2017年   53篇
  2016年   46篇
  2015年   37篇
  2014年   40篇
  2013年   105篇
  2012年   63篇
  2011年   83篇
  2010年   29篇
  2009年   17篇
  2008年   42篇
  2007年   30篇
  2006年   32篇
  2005年   29篇
  2004年   42篇
  2003年   34篇
  2002年   24篇
  2001年   19篇
  2000年   9篇
  1999年   4篇
  1998年   1篇
  1997年   8篇
  1996年   3篇
  1995年   1篇
  1994年   4篇
  1993年   3篇
  1992年   1篇
  1991年   3篇
  1990年   2篇
  1989年   1篇
  1988年   1篇
  1987年   1篇
  1986年   1篇
  1983年   1篇
  1978年   1篇
  1977年   1篇
  1967年   2篇
  1959年   1篇
排序方式: 共有919条查询结果,搜索用时 62 毫秒
51.
52.
ABSTRACT

This paper analyzes simultaneous strikes during the first half of the 20th century in North America. The transformation of production in copper, lead, zinc, and silver mining districts determined the formation of a working class that operated between Mexico and the United States. Therefore, the labor conflicts combined market circumstances and management-imposed homologation of work structures across firm divisions with the international coordination of miners. The paper describes the emergence, growth, and demise of a regional industrial system.  相似文献   
53.
54.
In this paper symbolic inclusion/exclusion processes in sport with respect to gender and ethnicity among adolescents (n = 1025) are analyzed from a social-critical perspective. It was found that sport participation preferences of young people are still influenced by dominant normative gendered and racial/ethnic images. Sport can serve not only as an agent of integration among youth, but is also used to differentiate and discriminate. On one hand sport participation is less predictable with respect to gender, due for example to interactions with ethnicity. Although ethnic minority girls participate the least in sport, ‘black,’ traditional ‘masculine‘ sports such as soccer and fighting/self-defense are valued relative highly. On the other hand, the data show that especially the male adolescents symbolically exclude girls from ‘masculine’ sports such as soccer; in addition for both ethnic minority and majority boys the fear of being labelled as a ‘sissy’ works as a strong mechanism of self-exclusion from participation in traditional ‘feminine’ sports. However, stereotypical normative images are not only confirmed through sport (participation), but also continually challenged.Researcher/lecturer, Tilburg University. Research interest in inclusionary and exclusionary mechanisms in sport, especially with respect to gender, ethnicity and sexuality.Senior researcher, Utrecht University. Major research interest in gender, ethnicity and leadership positions in sport.  相似文献   
55.
56.
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   
57.
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   
58.
59.
60.
Citalopram, an antidepressant whose use has become more widespread in Spain in recent years participates directly and indirectly in the lethal mechanism in voluntary and involuntary poisonings. There were 30 cases of autopsies in the Madrid region where citalopram and other psychoactive substances (psychotropic drugs, alcohol, opiates) were detected in the corpses. The postmortem citalopram levels in relation to the manner and mechanism of death were evaluated, and a significant difference between the toxic and nontoxic cases (p < 0.01) was found. We studied the citalopram blood levels alone and along with other psychoactive products, and these cases were then further divided into those where the compounds were at deadly levels and those which were not. We found a range of citalopram levels between 0.37 and 0.83 microg/mL in which some cases were associated with citalopram toxicity and others were not. Citalopram blood levels of less than 0.35 microg/mL did not lead to fatal poisoning when it was the sole substance detected.  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