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   56157篇
  免费   1698篇
  国内免费   1279篇
教育   32291篇
科学研究   13502篇
各国文化   77篇
体育   4288篇
综合类   3065篇
文化理论   97篇
信息传播   5814篇
  2024年   29篇
  2023年   257篇
  2022年   767篇
  2021年   1267篇
  2020年   1585篇
  2019年   1353篇
  2018年   1129篇
  2017年   1171篇
  2016年   1428篇
  2015年   1792篇
  2014年   3835篇
  2013年   4693篇
  2012年   5122篇
  2011年   5124篇
  2010年   3404篇
  2009年   3025篇
  2008年   3205篇
  2007年   3751篇
  2006年   3633篇
  2005年   3030篇
  2004年   2533篇
  2003年   2081篇
  2002年   1707篇
  2001年   1281篇
  2000年   726篇
  1999年   327篇
  1998年   217篇
  1997年   160篇
  1996年   111篇
  1995年   72篇
  1994年   76篇
  1993年   67篇
  1992年   48篇
  1991年   41篇
  1990年   20篇
  1989年   33篇
  1988年   6篇
  1986年   1篇
  1985年   3篇
  1984年   1篇
  1983年   1篇
  1979年   2篇
  1978年   3篇
  1977年   1篇
  1976年   2篇
  1957年   14篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Creating and disseminating knowledge through research and teaching has long been regarded as the hallmark of the modern university. However, new university business models have called into question the ‘bundling’ of teaching and research, and sustained research on the relationship between teaching and research has found little evidence of an insoluble connection between the two activities. In this article, we explore the relationship between teaching and research from the perspective of universities’ institutional discourse. We use corpus-assisted discourse analysis to examine the relationship between research and teaching as presented in two sets of institutional texts currently influential in UK Higher Education: Research Excellence Framework environment statements and Teaching Excellence Framework provider submissions (a total of 2143 documents and 12,492,071 words). Our findings show that, while universities emphasise the value of research to their teaching, they do not always emphasise (or sometimes even decry) the influence of teaching on their research. We empirically evidence that, according to what universities themselves write in institutional texts, teaching and research are not always in a mutually beneficial entanglement, but often rather a one-way relationship in which research expertise and institutional prestige are used to bolster claims of teaching excellence. This has implications for the communication of both the vision and the purpose of a university in regulatory exercises and wider policy, but also speaks to the broader idea and practice of being a university in the twenty-first century.  相似文献   
2.
In recent years, the transnational movement of people has resulted in increasing tension and debates about national identity. The present research utilized a discourse analytic approach to examine accounts of national identity in the U.S. among native-born U.S. residents, Mexicans living in Mexico, and Mexicans living in the U.S. Our analysis focused on two sets of diverging accounts of national identity. A first set involved participants' explanations of national identity as natural/essential, “felt”, or conditional, which served to either constrain how “American” immigrants could be or allowed for a more inclusive definition of national identity. A second set of accounts involved participants theorizing the national polity as a multicultural or monocultural space which functioned to construct national boundaries as permeable or reinforced (White) American dominance. These patterns of talk emerged across all interviews, although U.S. participants attended to more flexible and dilemmatic (e.g. inclusionary and exclusionary) accounts of national identity. We discuss the implications for the complexity of national identity.  相似文献   
3.
[目的/意义]基于版权保护的演化博弈分析,有助于探究数字内容产品的原创主体对仿冒行为是否具有容忍度,以及不同仿冒水平下实施版权保护的策略选择,对规范数字内容产品市场主体行为具有一定指导意义。[方法/过程]首先借助演化博弈模型,分析原创主体与仿冒主体的利益演化过程,探究版权保护下原创主体对仿冒水平的容忍行为;然后通过细化博弈双方的利润函数模型,探究原创主体容忍度水平的决定因素。[结果/结论]原创主体对较小的仿冒水平存在一定的容忍度,对较高的仿冒水平零容忍。最大仿冒水平容忍度由仿冒交叉收益系数、收益模型常系数、产品研发成本系数和原创主体的产品研发努力水平倍数4个因素共同决定。  相似文献   
4.
ABSTRACT

The aims of this study were to identify profiles of sedentary behaviour (SB) patterns, based on leisure-time self-reported SB modalities (screen, educative, social, and relaxing) and to evaluate changes in these profiles over 2 years among Spanish youth aged 8–18 years. Latent profile analysis (LPA), a data-driven analytic approach, was used to identify groups of boys and girls (n = 1553; 48% girls; mean±SD age: 12.56 ± 2.49 y) with distinct SB profiles using the SB modalities (time/d) as input variables. Latent transition analysis, an extension of LPA that uses longitudinal data, was used to analyse 2-year changes in these profiles. At baseline, four and three SB profiles were found among boys (labelled: screen, educative, social, and relaxing) and girls (labelled: screen/social, educative, and relaxing), respectively. Overall, more girls (range: 48%-67%) had the same profile over time, than boys (40%-52%). Participants with a screen or relaxing SB profile at baseline were more likely to have an educative profile after 2 years. Youth with a social and an educative SB profile at baseline were more likely to transition to profiles characterized by higher screen and social SB, respectively. Using a novel and person-centered approach, this study identified gender-specific SB profiles that were moderately stable over time.  相似文献   
5.
[目的/意义] 两个国家间的创新合作机会有些是显性直接的,有些是潜在间接的。在此试图构建一种计量和分析专利引用关系的方法,用于发现两国间潜在的间接创新合作机会。[方法/过程] 全球价值链上不同环节专利之间的引用关系中,蕴含着相互衔接、配套的间接合作关系,而不同环节的专利通常具有不同的功能,即IPC存在一定跨越度。因此,设计"专利引用跨越度"指标及算法,用于计量和筛选专利引用网络中"引用跨越度"达到预设阈值的专利引用关系,作为发现间接创新合作机会的基础数据。以新加坡在中国获得授权的发明专利为样本,基于专利引用跨越度计量并配合人工解读和识别,发现中新两国间一系列的间接创新合作机会。[结果/结论] 基于专利引用跨越度计量的两国间间接创新合作机会发现的方法,被实验检验为有效。  相似文献   
6.
目的:探讨不同负荷运动训练对大鼠骨骼肌线粒体三羧酸循环的影响及其机制。方法:将雄性Wistar大鼠50只随机均分为5组:安静对照组(C)、低负荷运动训练组(LT)、中等负荷运动训练组(MT)、高负荷运动训练组(HT)和极高负荷运动训练组(ST),每组10只。各运动组分别进行6周的跑台运动训练。训练方案结束后,取腓肠肌样本,提取线粒体,测定线粒体柠檬酸合成酶(CS)、异柠檬酸脱氢酶(ICD)和α-酮戊二酸脱氢酶(α-KGDHC)活性;线粒体Ga2+含量、胞浆NADH、NAD+、ATP和ADP含量,以及ICD mRNA转录水平。结果:(1)不同负荷运动训练组线粒体CS、ICD和α-KGDHC的活性均显著高于安静对照组(P < 0.01),且CS和ICD活性由高到低顺序均为:MT组 > HT组 > ST组 > LT组 > C组,α-KGDHC活性由高到低顺序为:HT组 > MT组 > ST组 > LT组 > C组。(2)不同负荷运动训练组线粒体Ca2+ 含量均显著高于安静对照组(P < 0.01),其含量由高到低顺序为:MT组 > HT组 > ST组 > LT组 > C组;胞浆NADH/NAD+和ATP/ADP的比值均显著低于安静对照组(P < 0.01),其比值由低到高顺序为:MT组 < ST组 < HT组 < LT组 < C组。(3)不同负荷运动训练组ICD mRNA转录水平均高于安静对照组(P < 0.01),其水平由高到低顺序为: MT组 > HT组 > ST组 > LT组 > C组。结论:低负荷、中等负荷、高负荷及极高负荷运动训练均可提高大鼠骨骼肌线粒体三羧酸循环功能,且中等负荷运动训练效果最佳。其机制与胞浆NADH/NAD+和ATP/ADP比值、线粒体摄钙能力及限速酶基因的表达有关。  相似文献   
7.
王思茗  滕广青 《图书情报知识》2020,(3):109-118,F0003
[目的/意义]领域知识的跨学科交叉研究能够打破学科间的壁垒,有助于发现重大科学问题的解决方案。[研究设计/方法]基于图书情报学领域文献题录信息构建轻量级领域知识图谱,从中提取学科信息、国家信息、时间信息及其关联,采用时间与空间相结合的多维度分析方法,对学科交叉的演化进程以及国家差异进行跟踪与分析。[结论/发现]图书情报学领域内学科交叉现象日渐显著,各国家的学科交叉程度与倾向存在差异,一些目前尚不突出的交叉学科方向值得关注。[创新/价值]采用多维度视角分析学科交叉现象,相关结论可以为国家科技战略制定及学科发展规划提供有益参考。  相似文献   
8.
ABSTRACT

Olfaction has been described as one of the least studied of the senses. This has certainly proven true in Communication. This project applies Ethnography of Communication and Cultural Discourse Analysis to examine the role that olfaction plays in the cultural meaning systems of two speech communities: residents surrounding the Gowanus Canal and bereaved parents. The cultural hub used to explore the cultural significance of olfaction in both speech communities is feeling. The analyses illustrate how emotions are tied to associated sensations and further become activated through radiants of dwelling, relating and acting. The analysis also shows how olfaction may serve to unify and separate members of a community. The significance of this research encourages stretching the boundaries of communication studies by examining the less studied physical senses and the boundaries of Cultural Discourse Analysis by providing distinctions that others can incorporate when examining feelings.  相似文献   
9.
Child maltreatment is a complex and multifaceted construct in need of advanced statistical techniques to improve its measurement. The current study compared the predictive utility of a cumulative index to a factor analytic approach for constructing a measure of maltreatment. Data were from Waves III and IV of the National Longitudinal Study of Adolescent to Adult Health (Wave III: n = 14,800; Wave IV: n = 12,288). As adults, participants retrospectively reported on their childhood experiences of physical abuse, sexual abuse, emotional abuse, physical neglect, supervisory neglect, and social services investigations. Both the cumulative index and a two-factor solution showed evidence of convergent validity, predicting lifetime incidence of homelessness, being paid for sex, and various measures of running away or living apart from biological parents, and prospectively predicting depression, substance use, and criminal behavior. The latent variables, derived from a factor analytic approach, had greater explanatory power for many outcomes compared to the cumulative index, even when controlling for sociodemographic variables. Results suggest that factor analysis is a better methodology than a cumulative index for measuring maltreatment in large datasets when explanatory power for external outcomes is of greatest concern.  相似文献   
10.
Critical educational literature suggests that an increased reliance upon performative technologies is currently transforming the very foundations from which teacher subjectivities are constructed. Arguably though, the number of studies pointing to this risk or tendency is considerably larger than the ones theorising why this should be the case. Further, in those cases where the relationship between performative technologies and teacher subjectivities is theorised, the psychological mechanisms that the technologies appeal to are seldom brought to the fore. Based on this, the purpose of this article is to theorise the psychological mechanisms that performative technologies appeal to and work through, by means of identifying, systematising and elaborating extant understandings of such mechanisms in the critical educational literature. The results are presented in the form of a conceptual framework (referred to as the CMIS-framework) which suggests that one and the same performative technology may play many different roles, where each such role appeals to and works through a particular psychological mechanism. Importantly, depending on the type of psychological mechanism that is appealed to, the CMIS-framework suggests that this will lead to teachers (un)consciously conducting particular forms of subjectivising work upon themselves, here referred to as compliance, mirroring, identification and self-realisation (CMIS).  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