全文获取类型
收费全文 | 167篇 |
免费 | 3篇 |
国内免费 | 8篇 |
专业分类
教育 | 123篇 |
科学研究 | 24篇 |
各国文化 | 1篇 |
体育 | 16篇 |
综合类 | 2篇 |
文化理论 | 1篇 |
信息传播 | 11篇 |
出版年
2023年 | 3篇 |
2022年 | 2篇 |
2021年 | 3篇 |
2020年 | 4篇 |
2019年 | 7篇 |
2018年 | 8篇 |
2017年 | 3篇 |
2016年 | 11篇 |
2015年 | 7篇 |
2014年 | 14篇 |
2013年 | 28篇 |
2012年 | 9篇 |
2011年 | 11篇 |
2010年 | 8篇 |
2009年 | 5篇 |
2008年 | 6篇 |
2007年 | 6篇 |
2006年 | 2篇 |
2005年 | 7篇 |
2004年 | 4篇 |
2003年 | 2篇 |
2002年 | 3篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 4篇 |
1983年 | 3篇 |
1981年 | 1篇 |
1979年 | 1篇 |
排序方式: 共有178条查询结果,搜索用时 15 毫秒
121.
Aaron Chin Bruce Elliott Jacqueline Alderson David Lloyd Daryl Foster 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(3):187-198
This study sought to identify kinematic differences in finger-spin bowling actions required to generate variations in ball speed and spin between different playing groups. A 12-camera Vicon system recorded the off-spin bowling actions of six elite and 13 high-performance spin bowlers, and the “doosra” actions of four elite and two high-performance players. Forearm abduction and fixed elbow flexion in the bowling arm were higher for the elite players compared with the high-performance players. The elite bowlers when compared with the high-performance players delivered the off-break at a statistically significant higher velocity (75.1 and 67.1 km/hr respectively) and with a higher level of spin (26.7 and 22.2 rev/s respectively). Large effect sizes were seen between ball rotation, pelvic and shoulder alignment rotations in the transverse plane. Elbow extension was larger for elite bowlers over the period upper arm horizontal to ball release. Compared to the off-break, larger ranges of shoulder horizontal rotation, elbow and wrist extension were evident for the “doosra”. Furthermore, the “doosra” was bowled with a significantly longer stride length and lower ball release height. Although not significantly different, moderate to high effect size differences were recorded for pelvis rotation, elbow extension and elbow rotation ranges of motion. 相似文献
122.
Heng Li Shi-ren Sun John Q. Yap Jiang-hua Chen Qi Qian 《Journal of Zhejiang University. Science. B》2016,17(3):181-187
The purpose of this review is to objectively evaluate the biochemical and pathophysiological properties of 0.9% saline (henceforth: saline) and to discuss the impact of saline infusion, specifically on systemic acid-base balance and renal hemodynamics. Studies have shown that electrolyte balance, including effects of saline infusion on serum electrolytes, is often poorly understood among practicing physicians and inappropriate saline prescribing can cause increased morbidity and mortality. Large-volume (>2 L) saline infusion in healthy adults induces hyperchloremia which is associated with metabolic acidosis, hyperkalemia, and negative protein balance. Saline overload (80 ml/kg) in rodents can cause intestinal edema and contractile dysfunction associated with activation of sodium-proton exchanger (NHE) and decrease in myosin light chain phosphorylation. Saline infusion can also adversely affect renal hemodynamics. Microperfusion experiments and real-time imaging studies have demonstrated a reduction in renal perfusion and an expansion in kidney volume, compromising O2 delivery to the renal parenchyma following saline infusion. Clinically, saline infusion for patients post abdominal and cardiovascular surgery is associated with a greater number of adverse effects including more frequent blood product transfusion and bicarbonate therapy, reduced gastric blood flow, delayed recovery of gut function, impaired cardiac contractility in response to inotropes, prolonged hospital stay, and possibly increased mortality. In critically ill patients, saline infusion, compared to balanced fluid infusions, increases the occurrence of acute kidney injury. In summary, saline is a highly acidic fluid. With the exception of saline infusion for patients with hypochloremic metabolic alkalosis and volume depletion due to vomiting or upper gastrointestinal suction, indiscriminate use, especially for acutely ill patients, may cause unnecessary complications and should be avoided. More education regarding saline-related effects and adequate electrolyte management is needed. 相似文献
123.
Information and Communication Technology (ICT) offers opportunities for governments to address key education challenges of quality, equity, and efficiency. While governments and educational institutions in developed countries may have taken up these opportunities, many developing countries in Asia and the Pacific region have often missed them out. This may be due to countries’ socioeconomic settings, approaches towards design and implementation of the ICT in education plan, and investment on research and development of ICT in education. This paper explores the current challenges of education in Asia and the Pacific and explains how these challenges may be overcome by the strategic use of ICTs when a holistic approach towards ICT in education is adopted. 相似文献
124.
Chin CE Ledesma HM Cirino PT Sevcik RA Morris RD Frijters JC Lovett MW 《Journal of learning disabilities》2001,34(1):2-8
Concurrent validity of the Kaufman Brief Intelligence Test (K-BIT) with the Wechsler Intelligence Scale for Children-Third Edition (WISC-III) was evaluated, as well as the K-BIT's accuracy as a predictor of WISC-III scores, in a sample of young children with reading disabilities. The two measures were administered to 65 children from Atlanta, Boston, and Toronto who ranged from 6-5 to 7-11 years of age at testing. Correlations between the verbal, nonverbal, and composite scales of the K-BIT and WISC-III were .60, .48, and .63, respectively. Mean K-BIT scores ranged from 1.2 to 5.0 points higher than the corresponding WISC-III scores. Standard errors of estimation ranged from 10.0 to 12.3 points. In individual cases, K-BIT scores can underestimate or overestimate WISC-III scores by as much as 25 points. Results suggest caution against using the K-BIT exclusively for placement and diagnostic purposes with young children with reading disabilities if IQ scores are required. 相似文献
125.
Meta-analysis of transformational school leadership effects on school outcomes in Taiwan and the USA
Joseph Meng-Chun Chin 《Asia Pacific Education Review》2007,8(2):166-177
Researchers have suggested that transformational leadership is an important aspect of effective schools; however, whether
the effects vary across related studies and the robustness of the overall effect size remain unclear. A meta-analysis technique
was used to synthesize the results of 28 independent studies and to investigate the overall relationship between transformational
school leadership and three measures of school outcomes. The study found that, in terms of the mean effect sizes, transformational
school leadership does have positive effects on teacher job satisfaction, school effectiveness perceived by teachers, and
student achievement.
Support for this paper was funded in part by the Taiwan’s National Science Council. The author is especially grateful to the
two reviewers for their valuable comments and Dr. Jin-Fu Wu for his helps of statistical analysis. 相似文献
126.
The vertical vibration of a large diameter pile embedded in inhomogeneous soil with hysteretic type damping is investigated based on the 3D axisymmetric model. Firstly, the pile is assumed to be a Rayleigh-Love rod with the consideration of its transverse inertia effect. Following this assumption, the pile-soil system is divided into several segments according to the stratification of the surrounding soil, and the dynamic interactions of the adjacent soil layers are simulated using the distributed Voigt model. Meanwhile, the surrounding soil is discretized into finite annular vertical zones to consider its radial inhomogeneity, and the force equilibrium and displacement coordination are satisfied at the interfaces of the adjacent soil zones and the interface of the pile-soil. Then, the analytical solution in the frequency domain and the semi-analytical solution in the time domain are obtained by solving the vibration governing equations of pile-soil system. Based on the solutions, a parametric analysis is conducted to investigate the influence of the transverse inertia effect on the dynamic response of the large diameter pile and its relationship with the pile parameters and the radial inhomogeneity of the surrounding soil. Finally, a comparison with the measured result and two other calculated results is presented to verify the effectiveness of the present solution. 相似文献
127.
128.
O’Brien Beth A. Mohamed Malikka Begum Habib Yussof Nurul Taqiah Ng Siew Chin 《Reading and writing》2019,32(4):909-937
Reading and Writing - Phonological awareness is critical for early reading acquisition across alphabetic as well as non-alphabetic languages. The grain size of phonological awareness varies with... 相似文献
129.
1997年中国成年人体质监测公报 总被引:46,自引:3,他引:43
中华人民共和国国家体育总局 《体育科学》1999,(1):1-3
监测未用随机整群取样方法,监测对象是 19个省、区、市的年龄为 18~60岁(女 55岁)的公民,最终参加运算的样本为 105 328人,获得 3 007 142个有效数据。主要结果为:男子平均身高为169.2 cm,女子为 158.6 cm;男子平均体重为 66.5 kg,女子为 56.8 kg。50岁前体重、相对体重随年龄增大,50岁后略减;北方人身材高大,南方人身材瘦小;东部地区人群体质好于中、西部。中国成年人体质方面存在的问题主要是有28.6%的人未达测定合格标准、开始向肥胖型发展等。提出改善中国成年人体质状况的主要措施主要有加强宣传,提高认识,扩大监测,吸引成年人参加体育活动等。 相似文献
130.
This work analyzes the limit cycle phenomena of nonlinear sampled-data systems by applying the methods of gain-phase margin testing, the M-locus and the parameter plane. First, a sampled-data control system with nonlinear elements is linearized by the classical method of describing functions. The stability of the equivalent linearized system is then analyzed using the stability equations and the parameter plane method, with adjustable parameters. After the gain-phase margin tester has been added to the forward open-loop system, exactly how the gain-phase margin and the characteristics of the limit cycle are related can be elicited by determining the intersections of the M-locus and the constant gain and phase boundaries. A concise method is presented to solve this problem. The minimum gain-phase margin of the nonlinear sampled-data system at which a limit cycle can occur is investigated. This work indicates that the procedure can be easily extended to analyze the limit cycles of a sampled-data system from a continuous-data system cases considered in the literature. Finally, a sampled-data system with multiple nonlinearities is illustrated to verify the validity of the procedure. 相似文献