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131.
Chen Ting Tong Fan Wu Xiao-yu Zhu Ling Yi Qiu-zi Zheng Jing Yang Ru-lai Zhao Zheng-yan Cang Xiao-hui Shu Qiang Jiang Ping-ping 《Journal of Zhejiang University. Science. B》2020,21(11):885-896
Journal of Zhejiang University-SCIENCE B - The pathogenesis of very-long-chain acyl-CoA dehydrogenase (VLCAD) deficiency is highly heterogeneous and still unclear. Additional novel variants have... 相似文献
132.
According to the definition of the new hypothetical states which have obvious physical sig-nificance and are termed as no-gravity static and accelerated states, a method for exact computa-tion of the parallel robot's generalized inertia matrix is presented. Based on the matrix theory, the generalized inertia matrix of the parallel robot can be computed on the assumption that the robot is in these new hypothetical states respectively. The approach is demonstrated by the Delta robot as an example. Based on the principle of the virtual work, the inverse dynamics model of the robot is formulized after the kinematics analysis. Finally, a numerical example is given and the element dis-tribution of the Delta robot's inertia matrix in the workspace is studied. The method has computational advantage of numerical accuracy for the Delta robot and can be parallelized easily. 相似文献
133.
Different from conventional mechanical systems with single degree of freedom (DOF),the main idea of the system of hybrid-driven precision press is to combine the motion of a constant speed motor with a servomotor via a two-DOF mechanism to provide flexible output. In order to make the feasibility clear, this paper studies theoretically the dynamic characteristics of this hybriddriven mechanical system. Firstly,the dynamics model of the whole electromechanical system is set up by combining dynamic equations of DC motors with those of two-DOF nine-bar mechanism deduced by the Lagrange‘s formula. Secondly through the numerical solution with the fourth Runge-Kutta, computer simulation about the dynamics is done, which shows that the designed and optimized hybrid-driven precision press is feasible in theory. These provide theoretical basis for later experimental research. 相似文献
134.
135.
Application of system dynamics for assessment of sustainable performance of construction projects 总被引:8,自引:0,他引:8
INTRODUCTION Sustainable development is commonly definedas meeting the needs of the present without compro-mising the ability of future generations to meet theirown needs (WCED, 1987). All industries, includingthe construction industry should contribute to themission. Compared to other industries, constructionactivities are generally considered to have more im-pact on the environment, which provides the basicconditions for the sustainability and development oflife on the Earth. The… 相似文献
136.
What Makes a Student Group Successful? Student-Student and Student-Teacher Interaction in a Problem-Based Learning Environment 总被引:1,自引:0,他引:1
Lindblom-Ylänne Sari Pihlajamäki Heikki Kotkas Toomas 《Learning Environments Research》2003,6(1):59-76
This study investigated student-student and teacher-student interaction in a problem-based course and looked at study success in relation to group dynamics and approaches to studying. Data for this study were provided by 31 law students who were enrolled in a course in legal history at the University of Helsinki in February 2001. The students were divided into three small groups that were tutored by one teacher. Both the students and the teacher were interviewed. The interaction between the students and their teacher, and the group dynamics of each subgroup, were observed during the tutor sessions. The results showed that the student groups were very different from each other in terms of study success, group dynamics and communication between the group members. One group achieved significantly higher grades than the other two groups. There was only one clear difference between the three groups. The interviews and observations showed that the students in the best group participated more evenly and actively in the discussions than students in the other two groups. 相似文献
137.
This study attempts to make inferences about the mechanisms that drive network change over time. It adopts simulation investigation for empirical network analysis to examine the patterns and evolution of relationships formed in the context of a massive open online course (MOOC) discussion forum. Four network effects—homophily, reciprocity, transitivity, and preferential attachment—were tested to explain the dynamic mechanisms of interaction in the MOOC forum. Understanding the network dynamics of relationships will allow us to explore how to develop a robust peer-supported learning environment and in turn improve the online learning experience in MOOCs. 相似文献
138.
本文论述了非智力因素与外语学习的关系,及非智力因素、动力、兴趣和性格等在外语学习中的作用,并指出培养学生非智力因素的重要性。 相似文献
139.
郭茂政 《黄冈师范学院学报》2004,24(3):75-76,80
导出了在无外力作用下两体运动的相对动力学方程及内力功的计算式,方便了求解有关力学问题. 相似文献
140.
INTRODUCTIONMoleculardynamics (MD)simulationwasfoundtobeanimportantmethodologyforstudyofcondensedmatter (Tsuzukietal.,1 996) .Kiselevan 相似文献