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1.
借鉴了运动心理学有关球感的理论,依据排球正面扣球动作技术的时间与空间特征,结合多年教学的实践经验,在分析与探讨了球感练习对排球正面扣球动作技能形成的作用的基础上,对排球正面扣球动作技术教学申球感练习选择的依据、练习顺序、练习手段及基本要求以及运用球感练习的基本原则等问题进行了分析与讨论。  相似文献   
2.
介绍了实际生产过程中加工内扁椭球面时,求算合适铣刀半径的问题,通过推导,给出了求算最大铣刀半径公式和推荐适当的系数,以便机床操作者和工程技术人员参考选用。  相似文献   
3.
Increasingly, online learning is perceived as an effective method of instruction. Much recent educational research has focused on examining the purposes and situations for which online education is best suited. In this paper, students enrolled in two online courses are compared with their peers enrolled in equivalent classroom‐based courses to investigate aspects of the relationship between learning style and mode of delivery. Student satisfaction measures are taken from participants in both modes of delivery and compared with student learning style. Feedback from the ‘Reflector’ learning style demonstrates higher satisfaction levels with the online mode of delivery compared with their matched counterparts following equivalent classroom‐based courses. Therefore, whilst ‘Reflectors’ might be regarded as Introverts in the traditional classroom setting, the additional time for reflection offered by online delivery makes this group more likely to contribute to online discussion, report higher satisfaction levels and generally behave more like online Extraverts.  相似文献   
4.
利用强极值原理将带电导体静电场内、外等值面边值问题化为几个常规的椭圆型Dirichlet边值问题,并建立它们相应的第一类Fredholm边界积分方程,由这些方程解的线性组合可构成原问题的解。  相似文献   
5.
对模具高速铣削加工的特点进行了分析,并对模具高速铣削加工的刀具系统、机床系统、CNC控制系统、CAD/CAE/CAM软件系统、安全防护和实时监控系统等关键技术进行了论述,提出了模具高速铣削加工技术的应用前景。  相似文献   
6.
以模式识别中英文文字识别和人脸检测为例,利用PIL库、pytesser库和OpenCV库实现了图像灰度转换、降噪处理、文字识别和目标检测。应用表明,Python处理实验数据的方法简便灵活,表征数据图形直观明了,适合在数字图像处理课程的模式识别章节中应用。  相似文献   
7.
球头铣刀铣削过程的物理建模与仿真   总被引:1,自引:0,他引:1  
给出了球头铣刀刃线几何模型,采用理论切削力分析与实验-系数识别相结合的方法,建立了新的螺旋刃球头铣刀的铣削力模型;建立了考虑刀杆柔性的球头铣刀铣削振动模型;考虑刀具动态变形和工件表面波纹对切削厚度的再生反馈,建立了球头刀铣削动力学模型,对动态铣削过程进行了仿真,证明离线仿真可以对铣削过程动特性做出准确的预测.  相似文献   
8.
Mg2Ni0.8Cr0.2-x wt.% CoO/Al2O3 (x=0.5, 1, 2 and 3) composites were prepared by mechanically milling sintered Mg2Ni0.8Cr0.2 alloy and CoO/Al2O3 compound for 45 h. The addition of CoO/Al2O3 compound resulted in the good kinetics properties of hydriding/dehydriding reaction of the composites. The composite with 1.0 wt.% CoO/Al2O3 catalyst could reach the maximum hydrogen absorption capacity (2.9 wt.%) within 5 min at 393 K under H2 pressure of 4 MPa, and can desorb rapidly at 493 K. The decomposition and synthesis of hydrogen molecule on Mg2Ni0.8Cr0.2 alloy surface was promoted by addition of CoO/Al2O3 catalyst. In addition, the formation of metallic Ni particles, strain and defects during the ball milling process also resulted in the improved hydrogenation performance of Mg2Ni-based alloys.  相似文献   
9.
Gaining and saving face are very important in Vietnam as a mechanism of social control, including the professional behaviour of teachers. Interviews with 15 lecturers (aged 24–37) at a teacher training college in a Central Coast province of Vietnam illustrated the relationship between their concepts of face and their beliefs about good teaching. Most were still strongly influenced by traditional Confucian beliefs about the role and position of teachers, the nature of teachers’ knowledge and the relationship between teachers and students. On the other hand, some teachers also were aware of, and to a limited extent open to, more modern ideas that seemed to be related to broad social changes and reforms in approaches to teaching and learning in recent decades in Vietnam. The findings suggest that some teacher educators are uncertain about the value of traditional professional wisdom in the context of critical changes in society and in education. The research also suggests that the concepts of face and saving face are important for teachers’ sense of agency, and that Vietnamese educational authorities could increase the effectiveness of innovations in teacher education by paying attention to the influence of concepts of face on the teachers’ beliefs and behaviours.  相似文献   
10.
为充分发挥数控机床的加工潜力和提高切削效率,作运用模糊控制方法研究了铣削加工过程的模糊自适应恒功率控制系统,并通过计算机仿真验证了控制方案的可行性;设计了系统的硬件和软件:进行了联机实验。实验结果表明,系统工作稳定可靠,平均可提高加工效率达20%以上。  相似文献   
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