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   35093篇
  免费   442篇
  国内免费   25篇
教育   24739篇
科学研究   3410篇
各国文化   365篇
体育   2986篇
综合类   23篇
文化理论   362篇
信息传播   3675篇
  2021年   344篇
  2020年   537篇
  2019年   781篇
  2018年   1072篇
  2017年   1025篇
  2016年   990篇
  2015年   627篇
  2014年   847篇
  2013年   6191篇
  2012年   768篇
  2011年   803篇
  2010年   665篇
  2009年   667篇
  2008年   730篇
  2007年   692篇
  2006年   654篇
  2005年   558篇
  2004年   621篇
  2003年   506篇
  2002年   534篇
  2001年   715篇
  2000年   762篇
  1999年   631篇
  1998年   379篇
  1997年   413篇
  1996年   459篇
  1995年   351篇
  1994年   368篇
  1993年   321篇
  1992年   508篇
  1991年   521篇
  1990年   520篇
  1989年   528篇
  1988年   476篇
  1987年   480篇
  1986年   461篇
  1985年   534篇
  1984年   413篇
  1983年   420篇
  1982年   347篇
  1981年   338篇
  1980年   353篇
  1979年   486篇
  1978年   367篇
  1977年   337篇
  1976年   278篇
  1975年   258篇
  1974年   262篇
  1973年   255篇
  1971年   249篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
ABSTRACT

The career path and significant professional accomplishments of librarian Valerie Bross (1954–2016) are described in this article. The awards and recognition she received are recounted and the influence of outside activities on her career is assessed. An attempt is made to capture what she was like as a professional, as well as what her unique characteristics were. A bibliography of her writings and a photograph are included.  相似文献   
112.
113.
Inconsistency is often considered an indication of deceit. The conceptualization of consistency used in deception research, however, has not made a clear distinction between two concepts long differentiated by philosophers: coherence and correspondence. The existing literature suggests that coherence is not generally useful for deception detection. Correspondence, however, appears to be quite useful. The present research developed a model of how correspondence is utilized to make judgments, and this article reports on four studies designed to elaborate on the model. The results suggest that judges attend strongly to correspondence and that they do so in an additive fashion. As noncorrespondent information accumulates, an increasingly smaller proportion of judges make truthful assessments of guilty suspects. This work provides a basic framework for examining how information is utilized to make deception judgments and forms the correspondence and coherence module of truth-default theory.  相似文献   
114.
115.
116.
117.
118.
BackgroundConsidering the potential cumulative effects of repetitive head impact (HI) exposure, we need sensitive biomarkers to track short- and long-term effects. Circulating small extracellular vesicles (sEVs) (<200 nm) traffic biological molecules throughout the body and may have diagnostic value as biomarkers for disease. The purpose of this study was to identify the microRNA (miRNA) profile in circulating sEVs derived from human plasma following repetitive HI exposure.MethodsHealthy adult (aged 18–35 years) soccer players were randomly assigned to one of 3 groups: the HI group performed 10 standing headers, the leg impact group performed 10 soccer ball trapping maneuvers over 10 min, and the control group did not participate in any soccer drills. Plasma was collected before testing and 24 h afterward, and sEVs were isolated and characterized via nanoparticle tracking analysis. Next-generation sequencing was utilized to identify candidate miRNAs isolated from sEVs, and candidate microRNAs were analyzed via quantitative polymerase chain reaction. In silico target prediction was performed using TargetScan (Version 7.0; targetscan.org) and miRWalk (http://mirwalk.umm.uni-heidelberg.de/) programs, and target validation was performed using luciferase reporter vectors with a miR-7844-5p mimic in human embryonic kidney (HEK) 293T/17 cells.ResultsPlasma sEV concentration and size were not affected across time and group following repetitive HI exposure. After 24 h, the HI read count from next-generation sequencing showed a 4-fold or greater increase in miR-92b-5p, miR-423-5p, and miR-24-3p and a 3-fold or greater decrease in miR-7844-5p, miR-144-5p, miR-221-5p, and miR-22-3p. Analysis of quantitative polymerase chain reaction revealed that leg impact did not alter the candidate miRNA levels. To our knowledge, miR-7844-5p is a previously unknown miRNA. We identified 8 miR-7844-5p mRNA targets: protein phosphatase 1 regulatory inhibitor subunit 1B (PPP1R1B), LIM and senescent cell antigen-like domains 1 (LIMS1), autophagy-related 12 (ATG12), microtubule-associated protein 1 light chain 3 beta (MAP1LC3B), integrin subunit alpha-1 (ITGA1), mitogen-activated protein kinase 1 (MAPK1), glycogen synthase kinase 3β (GSK3β), and mitogen-activated protein kinase 8 (MAPK8).ConclusionCollectively, these data indicate repetitive HI exposure alters plasma sEV miRNA content, but not sEV size or number. Furthermore, for the first time we demonstrate that previously unknown miR-7844-5p targets mRNAs known to be involved in mitochondrial apoptosis, autophagy regulation, mood disorders, and neurodegenerative disease.  相似文献   
119.
120.
Background: Somali Bantu refugees, with unique health information needs, created challenges for health and social service providers. Objectives: A service innovation was developed (i) to raise awareness, especially among local health and social service providers, about the Bantu refugees’ presence in the community, their culture, and their information needs and (ii) to deliver needed health information, emphasizing child health, to the Bantu mothers in their homes. Methods: The project consisted of: (i) a community conference targeting local health and social service providers, describing the refugees’ presence in the community, their culture, and information needs. (ii) Focus groups conducted with members of the Bantu population elicited additional information needs. (iii) Curriculum was developed based on identified needs, and (iv) the curriculum was delivered to the refugees in their homes. A clinical informationist and MP3 technology enhanced the project. Findings: Conference attendees’ evaluation responses indicated improved understanding of Bantu culture. Focus groups’ identification of health information needs provided a framework for the health education curriculum. A project website made educational materials available to other healthcare providers. Conclusions: The project raised awareness of the Bantus’ presence, culture, and information needs. Identification of other unmet needs demonstrated that additional support for refugees is required.  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