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   1895篇
  免费   99篇
各国政治   58篇
工人农民   240篇
世界政治   107篇
外交国际关系   77篇
法律   1039篇
中国共产党   1篇
中国政治   26篇
政治理论   426篇
综合类   20篇
  2023年   15篇
  2022年   13篇
  2021年   17篇
  2020年   44篇
  2019年   56篇
  2018年   78篇
  2017年   93篇
  2016年   81篇
  2015年   77篇
  2014年   89篇
  2013年   284篇
  2012年   76篇
  2011年   103篇
  2010年   57篇
  2009年   68篇
  2008年   88篇
  2007年   74篇
  2006年   76篇
  2005年   59篇
  2004年   58篇
  2003年   56篇
  2002年   42篇
  2001年   38篇
  2000年   30篇
  1999年   23篇
  1998年   25篇
  1997年   21篇
  1996年   13篇
  1995年   14篇
  1994年   18篇
  1993年   12篇
  1992年   7篇
  1991年   14篇
  1990年   12篇
  1989年   11篇
  1988年   13篇
  1987年   4篇
  1986年   6篇
  1985年   11篇
  1984年   14篇
  1983年   11篇
  1982年   11篇
  1981年   14篇
  1980年   11篇
  1979年   9篇
  1978年   5篇
  1977年   8篇
  1976年   7篇
  1973年   5篇
  1967年   3篇
排序方式: 共有1994条查询结果,搜索用时 15 毫秒
51.
This article aims to discern the extent to which managerial work is similar and different in the public and private sectors. Using propositions and structured categories for describing what managers do, this article compares results of an observational study conducted in the Canadian public sector with similar studies from the private sector. Through a comparison of work type, hours, location, activities, and contact patterns, this research finds few differences in managerial work activities between the two sectors, despite contextual and situational differences. Possible explanations are explored, implications of the findings are discussed, and future research directions are proposed.  相似文献   
52.
53.
Journal of Youth and Adolescence - Young adults experience social role transitions across multiple life domains, and a deeper understanding of the ways in which these simultaneous transition...  相似文献   
54.
Microbial communities have potential evidential utility for forensic applications. However, bioinformatic analysis of high-throughput sequencing data varies widely among laboratories. These differences can potentially affect microbial community composition and downstream analyses. To illustrate the importance of standardizing methodology, we compared analyses of postmortem microbiome samples using several bioinformatic pipelines, varying minimum library size or minimum number of sequences per sample, and sample size. Using the same input sequence data, we found that three open-source bioinformatic pipelines, MG-RAST, mothur, and QIIME2, had significant differences in relative abundance, alpha-diversity, and beta-diversity, despite the same input data. Increasing minimum library size and sample size increased the number of low-abundant and infrequent taxa detected. Our results show that bioinformatic pipeline and parameter choice affect results in important ways. Given the growing potential application of forensic microbiology to the criminal justice system, continued research on standardizing computational methodology will be important for downstream applications.  相似文献   
55.
Through the measurement of ethyl glucuronide in hair (hETG), it is possible to assess chronic alcohol abuse over time. In this paper, we present a study on hETG in Italian prison inmates. Analyses were performed by LC-MS according to a previously published method. Results were evaluated using the cut-offs established by the Society of Hair Testing. Positives samples (ETG > 30 pg/mg) accounted for 6% of all subjects, with concentrations ranging from 42 pg/mg up to 270 pg/mg, abstinent subjects (ETG < 7 pg/mg) accounted for 88%, and moderate alcohol consumption (7 < ETG < 30 pg/mg) for 6% of the subjects. No females displayed ETG values above 30 pg/mg. Among positive samples, only two subjects did not declare heavy alcohol consumption and were found strongly positive at 210 and 270 pg/mg. To the best of our knowledge, this represents the first study on ETG hair concentration on prison inmates.  相似文献   
56.
This study is the first to examine the background level of male DNA on underpants worn by females in the absence of sexual contact. Here, we examined 103 samples from the inside front of underpants from 85 female volunteers. Samples were examined for the presence of male DNA using NGM SElect and PowerPlex Y23 kits. Only five samples gave a “complete” Y-STR profile, even though 83.5% of our volunteers cohabited with a male. In all cases where a partner reference sample was available, the Y-STR profile matched the cohabiting partner. We have demonstrated that a Y-STR profile is not expected on the inside front of underpants worn by females after social contact alone. The results of this study are informative for evaluating the significance of a Y-STR profile on underpants in cases of alleged sexual assault.  相似文献   
57.
Trigger pull is the force that needs to be exerted on the trigger to discharge a firearm. The measurement of trigger pull can assist in the evaluation of the safety, function, and manufacturing characteristics associated with a firearm during the forensic firearm examination process. Nonetheless, the accuracy and uncertainty of trigger pull measurements may be affected by the measuring device, test procedure, and environmental conditions. In this work, an innovative finger-trigger interface device was developed to facilitate accurate trigger pull measurements. The idea was to reduce the variation related to the position of the measurement device on the trigger in existing measuring methods and devices. Three force sensors based on different technologies were initially evaluated. While two of the three sensors failed to produce data, the miniature capacitive plate sensor exhibited high precision and a linear response over the range of typical trigger pulls. To examine the effects of the finger-trigger interface on trigger pull measurement, different sensor housing prototypes were designed in silico and 3D printed for the construction of three finger-trigger interface devices. The performance of each finger-trigger interface device was evaluated by measuring the trigger pulls of several selected firearms and comparing the data to a previously published study. Our preliminary results demonstrated the novel finger-trigger interface device offered a new way to measure trigger pull in situ with acceptable accuracy and precision.  相似文献   
58.
Juvenile and family court judges are a professional group that have a significant amount of decision-making power in cases of sex trafficking of minors. The purpose of this project is to examine the association of juvenile and family court judges’ gender, race, and U.S. region with their attitudes and knowledge about sex trafficking of minors. Drawing from a survey of 55 juvenile and family court judges in the U.S., this study used standardized scales to measure attitudes and knowledge about child sex trafficking. Results indicate some differences by gender and geography in a sample of experienced judges across the U.S. The consistency of these findings are discussed in the context of other research and implications for targeted training.  相似文献   
59.
60.
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