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   26875篇
  免费   1234篇
各国政治   1452篇
工人农民   1081篇
世界政治   2156篇
外交国际关系   1002篇
法律   15884篇
中国共产党   5篇
中国政治   171篇
政治理论   6081篇
综合类   277篇
  2021年   156篇
  2020年   365篇
  2019年   536篇
  2018年   620篇
  2017年   745篇
  2016年   787篇
  2015年   565篇
  2014年   625篇
  2013年   3140篇
  2012年   728篇
  2011年   741篇
  2010年   635篇
  2009年   622篇
  2008年   757篇
  2007年   725篇
  2006年   722篇
  2005年   664篇
  2004年   662篇
  2003年   643篇
  2002年   612篇
  2001年   889篇
  2000年   850篇
  1999年   684篇
  1998年   406篇
  1997年   366篇
  1996年   319篇
  1995年   317篇
  1994年   346篇
  1993年   328篇
  1992年   495篇
  1991年   535篇
  1990年   473篇
  1989年   489篇
  1988年   460篇
  1987年   478篇
  1986年   490篇
  1985年   476篇
  1984年   422篇
  1983年   449篇
  1982年   338篇
  1981年   312篇
  1980年   257篇
  1979年   343篇
  1978年   236篇
  1977年   210篇
  1976年   184篇
  1975年   174篇
  1974年   197篇
  1973年   188篇
  1972年   163篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
971.
Certified aircraft mechanics represent the largest gender-based demographic disparity in aviation with a 49-to-1 male-to-female ratio. Recent research into women’s perspective on the aircraft mechanic career field revealed that a large majority of women felt unsure or negatively about their potential promotion opportunities and social acceptance. The purpose of this follow-on mixed-methods concurrent triangulation study was to explore the perspectives of men regarding the aforementioned topics to see if they differ from previously published research on women perceptions. A total of 587 men and 431 women completed an eight-question survey containing 5-point Likert-type and open-ended questions. The quantitative comparison consisted of the total 1018 responses, while only the survey responses from the 587 men were analysed for correlations and qualitative codes. Results indicated that there was a significant difference between the perceptions of men from those of the women regarding work environment safety and social acceptance. Additional correlation analysis revealed social acceptance to be a key variable when predicting career appropriateness, advancement opportunity and work environment safety. The 587 qualitative responses yielded results that differed from those of women, citing an assumption that women have the same advancement opportunities or be as socially accepted as men entering the field.  相似文献   
972.
Latinx youth living in the United States reside in a myriad of cultural and neighborhood contexts, yet little is known regarding how cultural values influence behavior problems across neighborhood contexts. Using a person–environment fit framework, the present study explored the degree to which youth cultural values were associated with their externalizing problems, and the degree to which this association was shaped by their neighborhood’s socioeconomic status (SES), and Latinx and immigrant concentration. The sample comprised of 998 Latinx youth (Female?=?54.2%), ages 10 to 14 years old (Mage?=?11.8), from three large United States metropolitan areas. Multilevel modeling methods indicated that increased fit between youth cultural values and neighborhood Latinx and immigrant concentration was associated with fewer externalizing problems, but only in higher SES neighborhoods. The results support the importance of studying social determinants of Latinx youth behavioral health, and provide implications for both neighborhood-level and individual-level prevention and intervention programming.  相似文献   
973.
This paper explores the political field that has opened up in the wake of the recent civil war in Nepal. We focus on cultural-political developments in agrarian districts, where some of the most intriguing openings, and indeed the most pernicious closures, can be witnessed (as opposed to the national-state restructuring that commands more media and popular attention). Our research asks what spaces open up in the emerging political field at the district scale to entrench or transform dominant cultural codes and sedimented histories of socio-economic inequality. Preliminary research identifies specific sectors of local governance that have emerged as significant sites of struggle over the shape and meaning of ‘democracy’, namely forest management and infrastructure development. The primary contribution of the paper lies in specifying an analytical approach to the study of ‘post-conflict’ governance at the local scale via three conceptual terrains of inquiry – governance and planning, political subjectivity, and cultural politics. The ultimate objective is to develop a framework for assessing the conditions of possibility for a democratic restructuring of economy and society to accompany the official political institutions of liberal democracy.  相似文献   
974.
This report describes a collaborative study on typing group-specific component (GC), conducted between the Central Research and Support Establishment and the forensic science laboratories of England, Wales and Northern Ireland. A population study (n=114) was performed. Fifty blood donors were selected to provide a distribution, slightly biased from normal, in favour of the GC 1F-1F and GC 1F-1S phenotypes. A protocol was devised for preparing large bloodstains. The strongest GC bands were obtained from the edge of a stain after the blood had been treated with K+/EDTA. Each laboratory received a representative portion of the large bloodstains for GC typing. Five of the eight laboratories correctly grouped all the bloodstains. No errors directly attitributable to the system were recorded in over 800 tests, indicating that GC in bloodstains can be typed reliably using the combination of isoelectric focusing in ultrathin narrow pH interval gels followed by immunofixation and silver staining.  相似文献   
975.
A simple but rigorous approach is offered for evaluating the evidential value of single locus DNA autoradiographs. This approach does not use a binning technique and it does not treat alleles as discrete variables. Instead, the allele distribution is considered to be continuous. The variation between two comparable bands is assessed using previously determined experimental parameters. The Bayesian treatment leads to an expression of the "quality of a match".  相似文献   
976.
The eyes of fourteen fatally abused children and sixteen control cases were examined histopathologically. Ten of the abused children showed intraocular change. The most common ocular changes were subdural hemorrhage of the optic nerve and retinal hemorrhage which involved all the layers of the retina, but most commonly the nerve fiber layer, ganglion cell layer and inner nuclear layer. The presence of blood cavities within the retina partially supported the hypothesis of traumatic retinoschisis. The control cases of non-abused children rarely showed intraocular hemorrhage.  相似文献   
977.
Signs of hypothermia injury were studied in rabbits cooled to a core temperature of 30 degrees C by immersion in ice water and thereafter rewarmed to 35 degrees C. Anaesthetized control rabbits were kept normothermic (37 degrees C) for a corresponding time (4 h). Creatine phosphokinase (CPK) activity increased 24 h after hypothermia to 20-fold in serum. In cerebrospinal fluid the activity was already significantly (5-fold) increased after hypothermia and was still as high at 24 h. Smaller increase was also found in the control normothermic rabbits both in serum (10-fold) and cerebrospinal fluid (2-fold). The values had returned to the initial level after 1 week. Small haemorrhages were observed in the brain at 24 h and slight scarring was seen in the myocardium of some rabbits which had lived 4 weeks following hypothermia. The results indicate that CPK can be a useful marker in the diagnostics of hypothermia death, especially in cerebrospinal fluid, which is less affected than blood by autolysis.  相似文献   
978.
"Current models of the European demo-economic system in pre-industrial times are based on strong assumptions about the predominant patterns of individual life courses. Now recent micro-studies of individual communities make it possible to check whether the actual patterns of life fit these assumptions. The findings for Belm present an amazing blend of confirmations and contradictions. In particular, the connection between marriage and the formation of a new self-supporting household is subject to doubt. Together with the findings of other micro-studies, the evidence for Belm suggests that the assumptions about mechanisms linking marriage to economic resources should be reconsidered, and that there is need for a dialogue between macro-theories and micro-history."  相似文献   
979.
This paper describes a simplified approach to calculating the Bayesian likelihood ratio for the case where two DNA single locus profiles are to be compared. It explains how the calculation allows for band shift and also for the variation in precision with molecular weight. A simple basic theory section explains the principles of the analysis but more detailed explanations are given in an advanced theory section. Experiments on substantial data collections are described which demonstrate the robustness of the method.  相似文献   
980.
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