全文获取类型
收费全文 | 8350篇 |
免费 | 97篇 |
国内免费 | 8篇 |
专业分类
教育 | 5671篇 |
科学研究 | 1113篇 |
各国文化 | 51篇 |
体育 | 607篇 |
综合类 | 3篇 |
文化理论 | 53篇 |
信息传播 | 957篇 |
出版年
2022年 | 45篇 |
2021年 | 100篇 |
2020年 | 132篇 |
2019年 | 178篇 |
2018年 | 295篇 |
2017年 | 270篇 |
2016年 | 264篇 |
2015年 | 159篇 |
2014年 | 270篇 |
2013年 | 1382篇 |
2012年 | 205篇 |
2011年 | 236篇 |
2010年 | 201篇 |
2009年 | 183篇 |
2008年 | 225篇 |
2007年 | 188篇 |
2006年 | 169篇 |
2005年 | 153篇 |
2004年 | 174篇 |
2003年 | 126篇 |
2002年 | 132篇 |
2001年 | 194篇 |
2000年 | 200篇 |
1999年 | 180篇 |
1998年 | 94篇 |
1997年 | 125篇 |
1996年 | 98篇 |
1995年 | 73篇 |
1994年 | 89篇 |
1993年 | 64篇 |
1992年 | 152篇 |
1991年 | 117篇 |
1990年 | 112篇 |
1989年 | 139篇 |
1988年 | 121篇 |
1987年 | 95篇 |
1986年 | 105篇 |
1985年 | 101篇 |
1984年 | 77篇 |
1983年 | 89篇 |
1982年 | 59篇 |
1981年 | 58篇 |
1980年 | 56篇 |
1979年 | 98篇 |
1978年 | 62篇 |
1977年 | 59篇 |
1976年 | 50篇 |
1975年 | 47篇 |
1974年 | 56篇 |
1973年 | 50篇 |
排序方式: 共有8455条查询结果,搜索用时 31 毫秒
51.
52.
53.
54.
In many Western science systems, funding structures increasingly stimulate academic research to contribute to practical applications,
but at the same time the rise of bibliometric performance assessments have strengthened the pressure on academics to conduct
excellent basic research that can be published in scholarly literature. We analyze the interplay between these two developments
in a set of three case studies of fields of chemistry in the Netherlands. First, we describe how the conditions under which
academic chemists work have changed since 1975. Second, we investigate whether practical applications have become a source
of credibility for individual researchers. Indeed, this turns out to be the case in catalysis, where connecting with industrial
applications helps in many steps of the credibility cycle. Practical applications yield much less credibility in environmental
chemistry, where application-oriented research agendas help to acquire funding, but not to publish prestigious papers or to
earn peer recognition. In biochemistry practical applications hardly help in gaining credibility, as this field is still strongly
oriented at fundamental questions. The differences between the fields can be explained by the presence or absence of powerful
upstream end-users, who can afford to invest in academic research with promising long term benefits. 相似文献
55.
Bahar Köymen Cathal O’Madagain Andreas Domberg Michael Tomasello 《Child development》2020,91(3):685-693
In collaborative problem solving, children produce and evaluate arguments for proposals. We investigated whether 3- and 5-year-olds (N = 192) can produce and evaluate arguments against those arguments (i.e., counter-arguments). In Study 1, each child within a peer dyad was privately given a reason to prefer one over another solution to a task. One child, however, was given further information that would refute the reasoning of their partner. Five-year-olds, but not 3-year-olds, identified and produced valid and relevant counter-arguments. In Study 2, 3-year-olds were given discourse training (discourse that contrasted valid and invalid counter-arguments) and then given the same problem-solving tasks. After training, 3-year-olds could also identify and produce valid and relevant counter-arguments. Thus, participating in discourse about reasons facilitates children’s counter-argumentation. 相似文献
56.
A Campus-Wide Investigation of Clicker Implementation: The Status of Peer Discussion in STEM Classes
Justin D. Lewin Erin L. Vinson MacKenzie R. Stetzer Michelle K. Smith 《CBE life sciences education》2016,15(1)
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
57.
58.
Karla K. McGregor Natalie Langenfeld Sam Van Horne Jacob Oleson Matthew Anson Wayne Jacobson 《Learning disabilities research & practice》2016,31(2):90-102
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
59.
K. Manuel Veth 《Soccer & Society》2017,18(1):132-143
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
60.
Danny Bavli Elishai Ezra Daniel Kitsberg Margarita Vosk-Artzi Shashi K. Murthy Yaakov Nahmias 《Biomicrofluidics》2016,10(2)
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