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   11161篇
  免费   204篇
  国内免费   408篇
教育   5691篇
科学研究   2759篇
各国文化   105篇
体育   350篇
综合类   462篇
文化理论   9篇
信息传播   2397篇
  2023年   40篇
  2022年   182篇
  2021年   225篇
  2020年   209篇
  2019年   221篇
  2018年   160篇
  2017年   164篇
  2016年   174篇
  2015年   285篇
  2014年   725篇
  2013年   1158篇
  2012年   941篇
  2011年   728篇
  2010年   644篇
  2009年   831篇
  2008年   752篇
  2007年   849篇
  2006年   949篇
  2005年   863篇
  2004年   415篇
  2003年   442篇
  2002年   342篇
  2001年   209篇
  2000年   93篇
  1999年   52篇
  1998年   28篇
  1997年   14篇
  1996年   24篇
  1995年   6篇
  1994年   5篇
  1993年   1篇
  1992年   7篇
  1991年   2篇
  1990年   2篇
  1985年   5篇
  1984年   5篇
  1983年   5篇
  1982年   5篇
  1981年   3篇
  1980年   1篇
  1979年   2篇
  1978年   5篇
排序方式: 共有10000条查询结果,搜索用时 148 毫秒
1.
Genetic variation in the angiotensin II type 1 receptor (AT1R) has an important effect on the outcome of acute coronary syndrome (ACS) initiated treatment with captopril. This study aims to investigate the impact of genetic polymorphism of AT1R (rs5186 and rs275651) on the ACS outcome in Iraqi patients treated with captopril. A total of 250 Iraqi individuals with ACS were included in this case—control study and they were divided into two study groups; Study group 1 included 125 participants who were prescribed captopril, 25 mg twice daily and study group 2 included 125 participants who received no captopril as part of their ACS treatment (control study). The AT1R gene (rs5186) CC genotype was found to be associated with ST-elevation myocardial infarction (STEMI) (Odd’s ratio (O.R) = 1.2, P = 0.7), while AC was associated with Non-ST-elevation myocardial infarction (NSTEMI) and unstable angina (UA) (O.R = 1.2, P = 0.8). AC genotype is more prone to have Percutaneous coronary intervention (PCI) after ACS attack (O.R = 1.2, P = 0.6). CC genotype had a risk to get less improvement (O.R = 1.6, P = 0.5), so might require higher doses of captopril during acute coronary insult. The AT1R gene (rs275651) AA genotype was associated with UA (O.R = 1.3, P = 0.9). AA and AT genotypes were more prone to have PCI after ACS attack (O.R = 3.9 P = 0.2, O.R = 3.5, P = 0.3 respectively) and thus requiring higher doses of captopril. We conclude that the AT1R rs5186, rs275651 genetic polymorphisms might partially affect the clinical outcome of ACS patients treated with captopril and might have captopril resistance which requires higher doses.  相似文献   
2.
BackgroundThe current state of knowledge regarding the role of non-offending fathers in supporting their sexually abused children is very scarce.ObjectiveThe objective of this study is to further our understanding of fathers’ roles following disclosure of their children’s sexual abuse (SA) by evaluating fathers’ perceptions of the impact of disclosure on their involvement and support of their children.Participants and methodThis qualitative study relies on individual semi-structured interviews conducted with 17 fathers of allegedly abused children.ResultsInductive thematic analysis first highlighted that some reported a period of disengagement from the child during which they put into question their role and attitudes, followed by a period of re-involvement. This period of difficulties experienced by some fathers in regard to their involvement towards their children was due to either their own important psychological distress, their ambivalence towards their child or even because of feelings of uneasiness experienced during physical contact with them. Despite this, findings indicate the presence of thoughts and attitudes that suggest children are a source of concern for fathers. The four forms of abuse-specific support previously observed among mothers (believing the child, seeking out professional services, protecting him/her from the offender, supporting him/her emotionally) were also observed among fathers. In accordance with the activation theory, a form of support specific to fathers, namely, encouraging the child to open up to and explore the world outside the family, thereby, fostering the child’s self-esteem development, was observed and constitutes a relevant finding.ConclusionClinical and empirical implications are discussed.  相似文献   
3.
《争取持久和平,争取人民民主!》是20世纪40年代中后期,欧洲九个社会主义国家的共产党和工人党为了一致行动而建立的情报局机关刊物。该刊物对新中国初期我国经济社会建设及成就进行了大量宣传与报道,对加强我国与世界其他爱好和平、渴求民主的各国人民加强互信、长存友谊贡献很大,也对当前学者研究新中国初期我国经济社会发展的过程、成就和经验等提供了原始史料,学术研究意义也很重大。但是,目前对这份刊物及其发挥过的重大作用了解的人少之又少,时值中国共产党成立100周年之际,对其创刊与发行的历史过程进行回顾、宣传中国社会经济发展的全貌进行展示、推动世界社会主义运动的作用进行肯定,意义都很重大。  相似文献   
4.
为深入理解图书情报学学术论文中所使用的研究方法的语义功能,为用户提供基于知识单元的细粒度知识服务,文章首先基于体裁理论来分析引文分析法、田野研究法、共词分析法、实验法、比较分析法和问卷调查法的知识单元构成。其次采用文本分析法,检索CSSCI图书情报学领域的18种期刊中使用以上6种研究方法的论文,进行知识单元层次的深度标引,作为知识库构建的语料。再次采用系统设计法,开发具有4种功能的学术论文研究方法学习系统。最后采用实验法,招募30位研究生使用系统,并根据用户体验对其可用性进行评价。结果表明:研究方法的体裁分析能较好地表示使用该方法开展研究的论文的语义功能,解释研究方法使用过程各部分的语义特征,为深入到知识单元层面的标引提供了基础,也为用户提供了基于知识单元的细粒度的检索点,知识库具有很好的可用性。文章揭示了论文研究方法使用过程各部分的语义特征,基于知识单元构成而设计的学术论文研究方法知识库能有效帮助用户学习研究方法,为学术论文研究方法内容的深度语义标引和本体开发奠定了基础,也为用户提供细粒度、多维度的论文研究方法内容的检索服务,对面向知识发现的知识组织研究具有参考意义。  相似文献   
5.
黄乐乐 《美育学刊》2020,11(2):116-120
现藏于南京博物院的一批无款写真头像《明人十二像册》,是中国写实画的一座高峰。对于这个像册的绘画风格,现当代学者多半都偏向认为是受到西方绘画的影响。但经与西方圣像画比较研究,像册仍属于中国本土的绘画传统,受到了宋代山水画和花鸟画高度写真精神的影响。  相似文献   
6.
坦桑尼亚是"一带一路"倡议通向非洲、辐射非洲内陆的重要门户,它在快速城市化过程中面临交通基础设施严重短缺问题。基于坦桑尼亚公路、铁路、机场、港口、人口和城市分布数据,运用GIS空间分析技术,结合交通通达指数模型,从县域与城乡两个层面对坦桑尼亚交通通达水平的空间格局特征进行定量分析。研究发现:1)坦桑尼亚县域交通通达水平空间分布极不均衡,高值连片区主要位于东北沿海和维多利亚湖沿岸,低值连片区主要位于中央铁路线中段以北、中央铁路线南部的广大地区;2)受地理区位、资源禀赋、殖民历史、政府政策等影响,城市与乡村地区之间的交通通达水平差异十分显著。研究结果有助于坦桑尼亚制定区域交通发展政策和优化资源配置,同时对中-坦产业精准对接和产能转移具有一定的促进意义。  相似文献   
7.
通过分析平昌冬奥会雪车和钢架雪车的赛况及主场优势,探索雪车和钢架雪车的发展规律,力求为我国雪车和钢架雪车项目的发展提供借鉴和参考。收集整理雪车和钢架雪车项目基本信息、平昌冬奥会赛况、获奖运动员信息及主场优势。研究发现:平昌冬奥会雪车和钢架雪车项目获奖运动员身材高大、年龄偏高;雪车和钢架雪车项目运动员跨界、跨项比例非常高;初学雪车和钢架雪车的年龄与运动成绩无直接联系,有丰富运动经历、运动水平较高、年龄略小(20岁以下)的其他项目运动员(田径)可转雪车和钢架雪车,且运动成绩提升速度快,通常在训练两年后,可达世界高级水平;雪车和钢架雪车训练和比赛的赛道极其稀缺,有限的赛道集中在东道主国家,这些国家的运动员较其他国家运动员有更多的时间熟悉赛道,这可能在一定程度上增加获胜的几率。  相似文献   
8.
Topic evolution has been described by many approaches from a macro level to a detail level, by extracting topic dynamics from text in literature and other media types. However, why the evolution happens is less studied. In this paper, we focus on whether and how the keyword semantics can invoke or affect the topic evolution. We assume that the semantic relatedness among the keywords can affect topic popularity during literature surveying and citing process, thus invoking evolution. However, the assumption is needed to be confirmed in an approach that fully considers the semantic interactions among topics. Traditional topic evolution analyses in scientometric domains cannot provide such support because of using limited semantic meanings. To address this problem, we apply the Google Word2Vec, a deep learning language model, to enhance the keywords with more complete semantic information. We further develop the semantic space as an urban geographic space. We analyze the topic evolution geographically using the measures of spatial autocorrelation, as if keywords are the changing lands in an evolving city. The keyword citations (keyword citation counts one when the paper containing this keyword obtains a citation) are used as an indicator of keyword popularity. Using the bibliographical datasets of the geographical natural hazard field, experimental results demonstrate that in some local areas, the popularity of keywords is affecting that of the surrounding keywords. However, there are no significant impacts on the evolution of all keywords. The spatial autocorrelation analysis identifies the interaction patterns (including High-High leading, High-Low suppressing) among the keywords in local areas. This approach can be regarded as an analyzing framework borrowed from geospatial modeling. Moreover, the prediction results in local areas are demonstrated to be more accurate if considering the spatial autocorrelations.  相似文献   
9.
This article examines the printed representation, and prosecutorial characterisation, of the movements, actions and motivations of early Quakers as vagrant. It argues that the prevalence and power of representing (and subsequently treating) early Quakers as vagrants is an understudied aspect of the social and cultural history of the Society of Friends, particularly in Interregnum England. As evidence, it interrogates a furious pamphlet debate between mid-century religious writers and preachers, who devoted much time and ink to painting Quakers as mendacious vagabonds, and Quaker ‘First Publishers’, who responded at length and in a striking way to these accusations. The article concludes that these images of Quakerism as a form of ‘spiritual vagrancy’ created historically significant echoes in English and Atlantic culture.  相似文献   
10.
The study evaluated the relationship among teaching, leadership, teacher certification, student and teacher number related factors, and index of economic, social and cultural status (ESCS), and science literacy from an international comparative perspective. 2015 dataset of the Programme for International Student Assessment for Turkey, Singapore, the United States, Korea, Italy, and Brazil was used. Two-level hierarchical linear models were established for analysis. Results revealed that school ESCS was the best predictor of science literacy across six countries and additionally teacher-related factors came to the forefront of science literacy performance. The study underlined policymakers should focus primarily on policies that increase equity in education. Furthermore, the effectiveness of investments made in factors related to leadership, teacher certification, the number of students and teachers, which contribute very little to science literacy performance, need to be more questioned. Inferences about the findings were discussed in detail, and recommendations for further research were made.  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