全文获取类型
收费全文 | 78篇 |
免费 | 1篇 |
专业分类
教育 | 58篇 |
科学研究 | 8篇 |
体育 | 6篇 |
文化理论 | 1篇 |
信息传播 | 6篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 2篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 4篇 |
2016年 | 1篇 |
2015年 | 3篇 |
2014年 | 2篇 |
2013年 | 14篇 |
2012年 | 4篇 |
2011年 | 3篇 |
2010年 | 1篇 |
2009年 | 1篇 |
2008年 | 1篇 |
2007年 | 3篇 |
2004年 | 3篇 |
2003年 | 1篇 |
2001年 | 1篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1986年 | 2篇 |
1984年 | 1篇 |
1981年 | 2篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1969年 | 1篇 |
1968年 | 2篇 |
1967年 | 1篇 |
1966年 | 3篇 |
1899年 | 1篇 |
排序方式: 共有79条查询结果,搜索用时 15 毫秒
41.
42.
43.
44.
Verne A. Stadtman Boris Ford Robert Berdahl John D. Turner Irving J. Spitzberg Sylvia Shimmin M. L. Shattock Denis E. Ince Michalina Vaughan Keith Soothill M. North Paul Fordham Charlotte Shea M. G. de St. V. Atkins Walter Little S. Williams J. M. M. Ritzen Murray Aitkin G. MacGregor-Reid Colin Lyas A. M. Ross P. G. Altbach Margaret C. Ives 《Higher Education》1980,9(1):105-125
45.
Verónica López Javier Torres‐Vallejos Boris Villalobos‐Parada Tamika D. Gilreath Paula Ascorra Marian Bilbao Macarena Morales Claudia Carrasco 《Psychology in the schools》2017,54(9):991-1003
Identifying and understanding predictors of school safety perceptions is important due to its consequences for students. However, it is not clear what school‐related factors most contribute to explaining students’ perception of school safety, and how they relate to community‐related factors such as neighborhood safety. The purpose of this study was to understand the factors associated with Chilean elementary and middle school students’ perceptions of school safety. We used a sample of 5,455 students from low socioeconomic status public schools, and analyzed the predictive value of peer physical and verbal victimization; teacher and school staff victimization; teacher's social support; and perception of safety in the students’ neighborhoods on perceptions of school safety. Findings showed that although different forms of school violence, particularly peer physical victimization and physical and sexual victimization from teachers and school staff, contribute to students’ perception of school safety, the highest contribution came from students perceiving their neighborhoods as unsafe. In contrast, teacher social support contributed to increased levels of perceived school safety. We discuss the need for school‐based interventions that address physical victimization and engage teachers in prosocial and less punitive approaches to foster a positive and safe school climate, and in fostering school–community partnerships. 相似文献
46.
In this paper, we develop an approach for solving the problem of sliding mode decentralized adaptive state-feedback tracking with continuous control actions for a class of uncertain nonlinear dynamical systems. In addition to the traditional asymptotic zero error tracking specification in the sliding mode decentralized model reference adaptive control (MRAC) problem formulation, here an additional requirement is specified explicitly in the problem statement. The tracking objective is described by a set of admissible reference trajectories, called a performance tube. The input signal to the reference model, selected within specified bounds, is used as a design parameter. The best reference trajectory is found by solving an additional optimization problem whose criterion penalizes the variance of the control signal. 相似文献
47.
In this contribution, we develop continuous completely decentralized state-feedback adaptive controllers with sliding mode for a class of large-scale interconnected systems with nonlinear interconnections with unknown time-varying state delays. The novel contribution of this paper is that asymptotically exact tracking within the framework of completely decentralized direct continuous adaptive control is possible also for a class of nonlinear plants with matched interconnections and disturbances. 相似文献
48.
Anna-Maria Strittmatter Boris Kilvinger Annika Bodemar Eivind Å. Skille Markus Kurscheidt 《Sport in Society》2019,22(10):1655-1673
AbstractThis article examines the current governance structures in international competitive snowboarding and analyses empirically how key actors operate within the diverging logics that shape such structures. We expand upon the existing literature on professional snowboarding by offering a more contemporary understanding of the constantly evolving processes of institutionalization. Qualitative data was gathered from the authors’ first-hand experiences with international snowboarding, based on (1) interviews with system insiders, (2) document analysis, and (3) participant observations. Two dominant and contradicting logics of competitive snowboarding were identified, forming a fragmented, dual institutional structure that we call the industry-based and nation-based governance model. Our findings suggest that recent professionalization processes have led to defragmentation efforts, thus signalling a shift towards a nation-based governance focus. Therefore, we conclude that other action sports that will join the Olympics, such as surfing and skateboarding, are advised to find solutions for mediating inherent contradictions of governance logics to avoid institutional fragmentation at an early stage. 相似文献
49.
Recently, extremely large benzenoid hydrocarbons have been synthesized. These compounds resemble graphite in many ways, and
have been named graphenes. Because of their nonstandard properties, graphenes have already found numerous applications, especially
as special-purpose materials in electronics. In this article we outline the basic chemical facts on graphenes.
Ivan Gutman is Professor of Physical Chemistry at the Faculty of Science, Kragujevac, Serbia. Among his interests are mathematical
methods in chemistry and the theory of polycyclic aromatic compounds.
Boris Furtula is secretary of the journal ‘MATCH Communications in Mathematical and in Computer Chemistry’. 相似文献
50.