全文获取类型
收费全文 | 5261篇 |
免费 | 83篇 |
国内免费 | 9篇 |
专业分类
教育 | 3611篇 |
科学研究 | 602篇 |
各国文化 | 49篇 |
体育 | 370篇 |
综合类 | 8篇 |
文化理论 | 67篇 |
信息传播 | 646篇 |
出版年
2023年 | 29篇 |
2022年 | 34篇 |
2021年 | 55篇 |
2020年 | 105篇 |
2019年 | 151篇 |
2018年 | 241篇 |
2017年 | 269篇 |
2016年 | 239篇 |
2015年 | 143篇 |
2014年 | 188篇 |
2013年 | 873篇 |
2012年 | 203篇 |
2011年 | 217篇 |
2010年 | 185篇 |
2009年 | 147篇 |
2008年 | 126篇 |
2007年 | 159篇 |
2006年 | 109篇 |
2005年 | 117篇 |
2004年 | 96篇 |
2003年 | 96篇 |
2002年 | 78篇 |
2001年 | 109篇 |
2000年 | 86篇 |
1999年 | 78篇 |
1998年 | 70篇 |
1997年 | 54篇 |
1996年 | 61篇 |
1995年 | 34篇 |
1994年 | 39篇 |
1993年 | 24篇 |
1992年 | 50篇 |
1991年 | 55篇 |
1990年 | 33篇 |
1989年 | 47篇 |
1988年 | 39篇 |
1987年 | 34篇 |
1986年 | 41篇 |
1985年 | 45篇 |
1984年 | 40篇 |
1983年 | 23篇 |
1982年 | 35篇 |
1981年 | 29篇 |
1980年 | 18篇 |
1979年 | 38篇 |
1978年 | 30篇 |
1977年 | 24篇 |
1974年 | 23篇 |
1972年 | 24篇 |
1971年 | 19篇 |
排序方式: 共有5353条查询结果,搜索用时 31 毫秒
1.
2.
ABSTRACTThe preservation of artefacts in museum collections is profoundly affected by fluctuations in temperature and, especially, relative humidity (RH). Since the late nineteenth century, many studies have been carried out on the best way to control hygrothermal conditions. In old buildings located in maritime temperate climate zones (such as Portugal) with strong thermal inertia, and which have low ventilation rate (relative to the volume and number of visitors), daily and seasonal hygroscopic inertia may help to assure the maintenance of RH stabilization conditions. The use of expensive active systems may be minimized through the passive behaviour of internal finishing building materials. This work presents the results of an experimental laboratory study conducted in a flow chamber to demonstrate the enormous potential of hygroscopic materials in stabilizing interior relative humidity. Based in these results and in-situ monitoring in a museum housed in a building, located in Porto, with a typical construction of the 1950s (granite masonry and reinforced concrete slabs), a numerical analysis was done to quantify the influence of hygroscopic materials in stabilizing the interior relative humidity. 相似文献
3.
4.
5.
6.
V. J. Hinton D. C. De Vivo R. Fee E. Goldstein Y. Stern 《Learning disabilities research & practice》2004,19(3):146-154
Duchenne Muscular Dystrophy (DMD) is a neurogenetic developmental disorder that presents with progressive muscular weakness. It is caused by a mutation in a gene that results in the absence of specific products that normally localize to muscle cells and the central nervous system (CNS). The majority of affected individuals have IQs within the normal range, generally with lower verbal than performance IQ scores. Prior work has demonstrated selective deficits on tests of verbal span and immediate memory. For the current study, 26 boys with DMD (and normal intellectual function) and their unaffected siblings were evaluated. Paired comparisons demonstrated that the children with DMD had significantly poorer academic achievement scores than their siblings, even though their vocabulary levels and home and educational environments were comparable. Children with DMD also had more behavioral concerns, physical disabilities, and poorer verbal memory spans. Linear regression indicated that behavioral concerns, executive function, and physical disability did not contribute substantially to academic performance, whereas performance on verbal span did. DMD presents with a selective developmental aberration in verbal span that has wide‐ranging consequences on learning skills. 相似文献
7.
8.
MICHAEL V. ELLIS 《Counselor Education & Supervision》1991,30(3):238-251
The purpose of this article was to revitalize and disentangle common misconceptions about a scientific agenda for clinical supervision. 相似文献
9.
Annemarie de Knecht-van Eekelen Steven Bakker Gerben van Lent 《Educational Measurement》2001,20(3):33-35
This is Part III of a three part series describing the consultancy and training demands that are encountered in technical assistance projects in Central and Eastern Europe. Part I dealt with strategic issues for a successful delivery of "Western Technical Assistance to Eastern Needs." Part II highlighted project management and co-operation aspects in delivering support to the Romanian Assessment and Examination Service. In this part, we address training of Polish subject experts who were preparing to take on responsibility for a decentralized and strongly innovative final exam, the Matura. 相似文献
10.
Wilson C Simpson SE van Emmerik RE Hamill J 《Sports biomechanics / International Society of Biomechanics in Sports》2008,7(1):2-9
The aim of this study was to examine the influence of skill of expert triple jumpers on the coordination variability of lower extremity intra-limb couplings. In contrast to the traditional motor learning perspective, we hypothesized that as skill and thus performance increases, movement coordination variability will also increase. Three-dimensional kinematic and ground reaction force data were collected during the hop-step transition phase of the triple jump. Relative motion plots and a modified vector coding technique were used to quantify the coordination variability across the trials. The results were consistent with a U-shaped curve, representing coordination variability, as skill increases. The high coordination variability in less skilled athletes is present while the appropriate characteristics defining the movement coordination patterns are acquired. This coordination variability may not be beneficial to performance. As the refinement of these characteristics is achieved, coordination variability decreases, resulting in a more consistent or regulated performance. In the final stages of developing a skilled performance, a functional variability is accessed that brings flexibility to the system allowing it to cope with perturbations. This study highlights the need to address the learning effect when analysing coordination variability from a dynamical systems perspective. 相似文献