全文获取类型
收费全文 | 1254篇 |
免费 | 24篇 |
国内免费 | 12篇 |
专业分类
教育 | 815篇 |
科学研究 | 226篇 |
各国文化 | 24篇 |
体育 | 100篇 |
综合类 | 5篇 |
文化理论 | 9篇 |
信息传播 | 111篇 |
出版年
2023年 | 9篇 |
2022年 | 11篇 |
2021年 | 27篇 |
2020年 | 30篇 |
2019年 | 41篇 |
2018年 | 49篇 |
2017年 | 72篇 |
2016年 | 49篇 |
2015年 | 38篇 |
2014年 | 49篇 |
2013年 | 190篇 |
2012年 | 47篇 |
2011年 | 53篇 |
2010年 | 51篇 |
2009年 | 38篇 |
2008年 | 46篇 |
2007年 | 39篇 |
2006年 | 30篇 |
2005年 | 34篇 |
2004年 | 19篇 |
2003年 | 26篇 |
2002年 | 25篇 |
2001年 | 28篇 |
2000年 | 24篇 |
1999年 | 27篇 |
1998年 | 4篇 |
1997年 | 6篇 |
1996年 | 13篇 |
1995年 | 11篇 |
1994年 | 8篇 |
1992年 | 12篇 |
1991年 | 13篇 |
1990年 | 7篇 |
1989年 | 7篇 |
1987年 | 10篇 |
1986年 | 8篇 |
1985年 | 17篇 |
1984年 | 12篇 |
1983年 | 12篇 |
1982年 | 10篇 |
1981年 | 5篇 |
1980年 | 7篇 |
1979年 | 5篇 |
1978年 | 7篇 |
1977年 | 4篇 |
1975年 | 11篇 |
1974年 | 6篇 |
1973年 | 7篇 |
1971年 | 7篇 |
1970年 | 4篇 |
排序方式: 共有1290条查询结果,搜索用时 15 毫秒
1.
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
2.
3.
Grace Y T Cheng 《Journal of the Medical Library Association》2004,92(4):445-458
OBJECTIVE: This article presents the results of complementary research studies on the behaviors of hospital clinicians in asking clinical questions and the relationship between asking of questions, outcome of information searches, and success in problem solving. METHODS: Triangulation in research methods--a combination of mailed questionnaires, interviews, and a randomized controlled study--was employed to provide complementary views of the research problems under study. RESULTS: The survey and interviews found that clinical problems (concerned mainly with therapy and equipment or technology) were expressed as statements rather than questions (average number of concepts = 1.7), that only slightly more than half (higher for doctors) of problems could be solved, and that the majority of clinical questions were not well formed. An educational workshop however improved clinicians' formulation of questions, but the use of structured prompting was found to improve building of hypotheses in the doctors' group without training. The workshop also improved satisfaction with the obtained information and success in problem solving. Nonetheless, for both the experimental and control groups, more structured and complete questions or statements did not mean higher success rates in problem solving or higher satisfaction with obtained information. CONCLUSION: The triangulation methods have gathered complementary evidence to reject the hypothesis that building well-structured clinical questions would mean higher satisfaction with obtained information and higher success in problem solving. 相似文献
4.
In this paper, the stability equation method is applied to the analysis of nonlinear systems with characteristics equations having complex coefficients. Three types of systems are studied: those with unstable open-loop poles, unstable characteristics roots or an equal number of open-loop poles and zeros. 相似文献
5.
The objective of the study is the cytocidal and inhibitory effect of energy-controllable pulse on ovarian cancer cell line SKOV3.Ovarian cancer cell suspension were treated by electric pulse with different parameters,.The inhibitory rate(IR) was assayed by modified colorimetric MTT methods,the growth curves of two test groups and one control group were also measured.and the ultrasturctureal changes were observed under electron microscopy(EM) and scan electron microscopy (SEM),It was found that the treated SKOV3 cell proliferated more slowly.IR was increased with the enhancement of pulse paramters,The ultrastructural study showed that morphological changes occured obviously.Swollen mitochondria,fracutured ridges,cytoplasmic vacuoles and membrane holes appeard in most of the processed cells,and a part of bilayer membrane was ruptured.It is indicated that irreversible electric breakdown occurred in some of the treated cells,and the electric pulse could kill cancer cell and inhibit its recovery and growth. 相似文献
7.
Steel plates are widely used in various structures, such as the deck and bodies of ships and bridges, and in the aerospace industry. In many instances, these plates are subjected to axial compression loads that predispose the sheets to instability and buckling. In this study, we investigate the buckling and post-buckling behaviors of steel plates having groove-shaped cutouts of various dimensions and angles using finite element method (FEM) (by ABAQUS software) and experimental tests (by an Instron servohydraulic machine). Boundary conditions were clamped by supports at upper and lower ends and free supports at the other edges. The results of both numerical and experimental analyses are compared, which show a very good agreement between them. Finally, based on the experimental findings, formulas are presented for the determination of the buckling load of such plates. 相似文献
8.
This paper examined the relationship between organizational ambidexterity and research commercialization in universities. The paper develops two types of organizational ambidexterity: structural ambidexterity and contextual ambidexterity that influence research commercialization. Through a dataset of 474 academic patent inventors in Taiwan, the results revealed structural and contextual ambidexterity factors are patenting-, licensing- and start-up-specific. Despite both types of ambidexterity are complementary in patenting and licensing, contextual ambidexterity outperform structural ambidexterity in fostering university start-up equity participation. To promote academic research commercialization, it is necessary to build up a university as a dual structural organization that allows pursuing research excellence and research commercialization at the same time. 相似文献
9.
10.