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   9938篇
  免费   114篇
  国内免费   19篇
教育   6653篇
科学研究   1219篇
各国文化   57篇
体育   987篇
综合类   4篇
文化理论   78篇
信息传播   1073篇
  2022年   76篇
  2021年   138篇
  2020年   169篇
  2019年   240篇
  2018年   382篇
  2017年   351篇
  2016年   345篇
  2015年   201篇
  2014年   322篇
  2013年   1558篇
  2012年   282篇
  2011年   306篇
  2010年   275篇
  2009年   239篇
  2008年   281篇
  2007年   242篇
  2006年   231篇
  2005年   206篇
  2004年   215篇
  2003年   156篇
  2002年   168篇
  2001年   225篇
  2000年   219篇
  1999年   201篇
  1998年   115篇
  1997年   143篇
  1996年   116篇
  1995年   82篇
  1994年   105篇
  1993年   76篇
  1992年   175篇
  1991年   126篇
  1990年   124篇
  1989年   144篇
  1988年   128篇
  1987年   99篇
  1986年   112篇
  1985年   105篇
  1984年   85篇
  1983年   93篇
  1982年   62篇
  1981年   62篇
  1980年   60篇
  1979年   106篇
  1978年   66篇
  1977年   63篇
  1976年   51篇
  1975年   58篇
  1974年   61篇
  1973年   52篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
At the University of Maine, middle and high school teachers observed more than 250 university science, technology, engineering, and mathematics classes and collected information on the nature of instruction, including how clickers were being used. Comparisons of classes taught with (n = 80) and without (n = 184) clickers show that, while instructional behaviors differ, the use of clickers alone does not significantly impact the time instructors spend lecturing. One possible explanation stems from the observation of three distinct modes of clicker use: peer discussion, in which students had the opportunity to talk with one another during clicker questions; individual thinking, in which no peer discussion was observed; and alternative collaboration, in which students had time for discussion, but it was not paired with clicker questions. Investigation of these modes revealed differences in the range of behaviors, the amount of time instructors lecture, and how challenging the clicker questions were to answer. Because instructors can vary their instructional style from one clicker question to the next, we also explored differences in how individual instructors incorporated peer discussion during clicker questions. These findings provide new insights into the range of clicker implementation at a campus-wide level and how such findings can be used to inform targeted professional development for faculty.  相似文献   
73.
74.
To explore the university experiences of students with learning disabilities (LD), 63,802 responses to the 2014 Student Experience in the Research University Survey were analyzed. Compared to other students, those with self‐reported LD (5.96 percent) had difficulty with assignments and had more obstacles caused by nonacademic responsibilities and imposed by their skill levels. Students with self‐reported LD sensed more bias toward people with disabilities on campus, and they were less satisfied with their overall experience. Interactions between disability status and age suggested even more challenges for older students who self‐reported LD. Approximately one‐third of students who self‐reported LD received accommodations. The rate of accommodations was higher among individuals who were wealthy, who lived alone, and who were out‐of‐state students. Compared to students who self‐reported LD but reported no accommodations, those with accommodations had more contact with faculty and less difficulty with assignments.  相似文献   
75.
This article focuses on the Soviet sports agency Sovintersport, which was created in the late 1980s and became an import–export company for everything related to sport in the Soviet Union. Sovintersport and its subsidiary companies were responsible for importing and exporting sporting equipment, negotiating sponsorship contracts with foreign companies, as well as the transferring of Soviet athletes and coaches to other countries. This article will, therefore, analyse the operations of Sovintersport and its subsidiary companies in the period between 1987 and 1991, with a special focus on foot-ball related operations. Sovintersport is in many ways is an excellent case study, which illustrates how international trading corporations that were set up during Gorbachev’s reign of the Soviet Union, operated. Sovintersport demonstrates how football in the Soviet Union turned from a spectator sport into a valuable asset that was worth capitalizing on.  相似文献   
76.
Cell-cell interactions play a key role in regeneration, differentiation, and basic tissue function taking place under physiological shear forces. However, current solutions to mimic such interactions by micro-patterning cells within microfluidic devices have low resolution, high fabrication complexity, and are limited to one or two cell types. Here, we present a microfluidic platform capable of laminar patterning of any biotin-labeled peptide using streptavidin-based surface chemistry. The design permits the generation of arbitrary cell patterns from heterogeneous mixtures in microfluidic devices. We demonstrate the robust co-patterning of α-CD24, α-ASGPR-1, and α-Tie2 antibodies for rapid isolation and co-patterning of mixtures of hepatocytes and endothelial cells. In addition to one-step isolation and patterning, our design permits step-wise patterning of multiple cell types and empty spaces to create complex cellular geometries in vitro. In conclusion, we developed a microfluidic device that permits the generation of perfusable tissue-like patterns in microfluidic devices by directly injecting complex cell mixtures such as differentiated stem cells or tissue digests with minimal sample preparation.  相似文献   
77.
The purpose of this study was to examine the factorial invariance of the Abbreviated Neighborhood Environment Walkability Scale (NEWS-A) across subgroups based on demographic, health-related, behavioral, and environmental characteristics among Nurses’ Health Study participants (N = 2,919; age M = 73.0, SD = 6.9 years) living in California, Massachusetts, and Pennsylvania. A series of multigroup confirmatory factor analyses were conducted to evaluate increasingly restrictive hypotheses of factorial invariance. Factorial invariance was supported across age, walking limitations, and neighborhood walking. Only partial scalar invariance was supported across state residence and neighborhood population density. This evidence provides support for using the NEWS-A with older women of different ages, who have different degrees of walking limitations, and who engage in different amounts of neighborhood walking. Partial scalar invariance suggests that researchers should be cautious when using the NEWS-A to compare older adults living in different states and neighborhoods with different levels of population density.  相似文献   
78.
In the article we solve path planning task for an agent being multirotor unmanned aerial vehicle (multicopter). We propose an approach of estimating path geometry constraints based on UAV flight dynamics model and control constraints. Than we introduce a new path finding method which takes into consideration those geometry constraints and study this method both theoretically and empirically.  相似文献   
79.
This study aimed to explore how children with learning disabilities (LD) perceive their quality of life (QoL) and to compare self‐reports and proxy reports regarding their QoL. Children with LD, their typically developing peers, their parents and teachers responded to the child, parent, and teacher forms of KINDLR Questionnaire for Measuring Health‐Related Quality of Life (Ravens‐Sieberer & Bullinger, 1998). Findings showed that children with LD reported significantly lower QoL scores than those reported by typically developing peers. Intraclass correlation coefficients (ICCs) and t‐test results showed that agreement between child reports and parent‐proxy reports was either low or moderate on each QoL dimension. Findings of the study may be used to raise awareness regarding the social and educational needs of children with LD in Turkey.  相似文献   
80.
This article analyzes the situation surrounding the education of the disabled in Kyrgyzstan. We provide a detailed discussion of the national legal and regulatory framework that guarantees the rights of persons with disabilities to education. We describe the actual situation in the country concerning access to education for this section of the population as well as other factors that impact it.  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