全文获取类型
收费全文 | 3188篇 |
免费 | 65篇 |
国内免费 | 2篇 |
专业分类
教育 | 2554篇 |
科学研究 | 99篇 |
各国文化 | 48篇 |
体育 | 152篇 |
文化理论 | 20篇 |
信息传播 | 382篇 |
出版年
2022年 | 14篇 |
2021年 | 22篇 |
2020年 | 61篇 |
2019年 | 75篇 |
2018年 | 99篇 |
2017年 | 113篇 |
2016年 | 94篇 |
2015年 | 77篇 |
2014年 | 80篇 |
2013年 | 813篇 |
2012年 | 75篇 |
2011年 | 95篇 |
2010年 | 84篇 |
2009年 | 83篇 |
2008年 | 87篇 |
2007年 | 85篇 |
2006年 | 77篇 |
2005年 | 67篇 |
2004年 | 70篇 |
2003年 | 67篇 |
2002年 | 70篇 |
2001年 | 50篇 |
2000年 | 51篇 |
1999年 | 40篇 |
1998年 | 37篇 |
1997年 | 53篇 |
1996年 | 33篇 |
1995年 | 41篇 |
1994年 | 39篇 |
1993年 | 34篇 |
1992年 | 35篇 |
1991年 | 34篇 |
1990年 | 32篇 |
1989年 | 31篇 |
1988年 | 23篇 |
1987年 | 19篇 |
1986年 | 29篇 |
1985年 | 30篇 |
1984年 | 24篇 |
1983年 | 26篇 |
1982年 | 21篇 |
1981年 | 15篇 |
1980年 | 26篇 |
1979年 | 23篇 |
1978年 | 29篇 |
1977年 | 24篇 |
1976年 | 16篇 |
1974年 | 11篇 |
1973年 | 10篇 |
1969年 | 10篇 |
排序方式: 共有3255条查询结果,搜索用时 15 毫秒
171.
This article describes an interactive activity that involves students participating in a memory recall test. Data collected from the activity may be used to illustrate the one‐sample t test or one‐sample sign test. 相似文献
172.
The current investigation was designed to identify emotion states students experience during mathematics activities, and in particular to distinguish emotions contingent on experiences of success and experiences of failure. Students’ task-related emotional responses were recorded following experiences of success and failure while working with an individualised computer-based mathematics learning environment. In addition, relations between these patterns of emotional responses after success and failure experiences and trait-like motivational variables, self-concept of ability, subject value, orientation to learning from errors, goal orientation and causal attributions, were examined. Two separate studies are reported. In Study 1 emotions associated with success and failure experiences in mathematics were investigated in relation to self-concept of ability, subject value and orientation to learning from errors. In Study 2, patterns of emotion following success and failure were examined in relation to students’ goal orientation and their causal attributions for success in school. 相似文献
173.
Lisa M. PytlikZillig Christy A. Horn Roger Bruning Stephanie Bell Xiongyi Liu Kamau O. Siwatu Mary C. Bodvarsson Doyoung Kim Deborah Carlson 《Contemporary educational psychology》2011,36(4):302-312
Two frequently-used discussion protocols were investigated as part of a program to implement teaching cases in undergraduate educational psychology classes designed for preservice teachers. One protocol involved synchronous face-to-face (FTF) discussion of teaching cases, which occurred in class after students had individually completed written case analyses as homework outside of class. The other was asynchronous computer-mediated (CM) discussion taking place outside of class, simultaneous to students’ completion of their written case analyses. Six class offerings of an undergraduate child development course taught by two instructors (three classes by each instructor) were randomly assigned within instructor in a quasi-experimental design to one of the three discussion conditions: FTF, CM, or no discussion of the cases across the semester. Findings indicated that both CM and FTF discussion conditions were associated with positive outcomes relative to the control condition. Both CM and FTF discussion related to higher cognitive–affective engagement with the cases than the control condition; and the CM discussion condition was associated with higher cognitive–affective engagement than FTF discussion. In contrast, FTF discussion, but not CM discussion, was associated with higher-than-control-condition case analysis ability at the end of the semester. Potential explanations for these findings and directions for future research are discussed. 相似文献
174.
175.
176.
177.
178.
Sanjeev Shruthi Molly Mary Thabah Bobby Zachariah Vir Singh Negi 《Indian journal of clinical biochemistry : IJCB》2021,36(2):185
To study oxidative stress in systemic lupus erythematosus (SLE) by estimating serum oxidised LDL (OxLDL), 8-hydroxy-2′-deoxyguanosine (8-OHdG), malondialdehyde (MDA), and total anti-oxidant status and to correlate with SLE disease activity and disease damage. Eighty SLE patients satisfying the Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) 2012 criteria and 80 healthy controls were studied. Exclusion criteria were infections, renal insufficiency, other connective tissue diseases, drug-induced lupus, smoking, alcohol consumption. Disease activity was measured by SLE disease activity index-2 K (SLEDAI), disease damage was quantified by SLICC-Damage Index (SDI). Sera was tested for OxLDL, 8-OHdG, and total antioxidant status (TAS) by double-antibody sandwich ELISA; MDA measured by Colorimetric assay. Oxidative stress markers were compared between group1- controls, group 2-mildly active SLE (SLEDAI ≤ 5), group 3- moderate to highly active SLE (SLEDAI ≥ 6). SLE patients had significantly higher MDA, 8-OHdG and lower TAS when compared to healthy controls, while OxLDL was similar in the three groups. MDA, 8-OHdG were significantly higher, TAS lower in group 3 compared to group 2. MDA had positive correlation with SLEDAI, TAS negatively correlated with SLEDAI. SLE with neuropsychiatric manifestations, vasculitis, anti-sdDNA antibodies had higher MDA, MDA/TAS ratio. SLE patients with thrombocytopenia, and vasculitis had higher OxLDL. Only OxLDL was significantly higher in those patients who have SDI > 1. SLE patients have increased oxidative stress measured by increases in MDA, 8-OHdG, and lower total antioxidant status that was associated with disease activity and some disease manifestations. However only OxLDL was associated with damage. 相似文献
179.
Ethics and Information Technology - Developing and implementing artificial intelligence (AI) systems in an ethical manner faces several challenges specific to the kind of technology at hand,... 相似文献
180.
Jyoti P. Gurung Moein Navvab Kashani Sanaz Agarwal Gonzalo Peralta Murat Gel Matthew A. B. Baker 《Biomicrofluidics》2021,15(3)
Many motile bacteria are propelled by the rotation of flagellar filaments. This rotation is driven by a membrane protein known as the stator-complex, which drives the rotor of the bacterial flagellar motor. Torque generation is powered in most cases by proton transit through membrane protein complexes known as stators, with the next most common ionic power source being sodium. Sodium-powered stators can be studied through the use of synthetic chimeric stators that combine parts of sodium- and proton-powered stator proteins. The most well studied example is the use of the sodium-powered PomA-PotB chimeric stator unit in the naturally proton-powered Escherichia coli. Here we designed a fluidics system at low cost for rapid prototyping to separate motile and non-motile populations of bacteria while varying the ionic composition of the media and thus the sodium-motive force available to drive this chimeric flagellar motor. We measured separation efficiencies at varying ionic concentrations and confirmed using fluorescence that our device delivered eightfold enrichment of the motile proportion of a mixed population. Furthermore, our results showed that we could select bacteria from reservoirs where sodium was not initially present. Overall, this technique can be used to implement the selection of highly motile fractions from mixed liquid cultures, with applications in directed evolution to investigate the adaptation of motility in bacterial ecosystems. 相似文献