MSI中规模计数器设计课程中的教法探讨     

黄晓明 《培训与研究》2010,(8):126-129

在数字电子技术课程的教学中有一章专门讨论时序逻辑电路的分析与设计,随着MSI中规模芯片的普及,大量的MSI计数器芯片进入了教材。由于课时的限制,教师不可能全面讲授这类芯片的设计方法,从而导致许多同学在考研时或在毕业后的工作中遇到不同的MSI芯片设计时就会出现困难。为此在本文中,我利用多年的教学经验总结归纳了此类问题的相关特征和简便的设计方法,为在校电子专业学习的同学们和从事电子专业教学的教师们提供一个参考。  相似文献   

Effects of online synchronous instruction with an attention monitoring and alarm mechanism on sustained attention and learning performance     

Chih-Ming Chen  Jung-Ying Wang 《Interactive Learning Environments》2018,26(4):427-443

Many studies have shown that learners’ sustained attention strongly affects e-learning performance, particularly during online synchronous instruction. This work thus develops a novel attention monitoring and alarm mechanism (AMAM) based on brainwave signals to improve learning performance via monitoring the attention state of individual learners and helping online instructors or teaching assistants to improve the sustained attention levels of learners with low-attention states as they perform online synchronous instruction activities. Totally, 83 and 65 Grade 7 students were randomly assigned to the experimental and control groups that respectively underwent online synchronous instruction with and without AMAM support. Analytical results reveal that the experimental group of learners exhibited significantly better learning performance and sustained attention than those in the control group, verifying that the AMAM efficiently promotes the learning performance and sustained attention of learners. Moreover, the proposed AMAM was more helpful in improving the learning performance of female learners than those of male learners and improved the sustained attention of both male and female learners. Furthermore, the sustained attention, frequency of attention alarms, and learning performance of the learners in the experimental group were strongly correlated, and the sustained attention and frequency of attention alarms strongly predicted learning performance.  相似文献   

双电机驱动伺服系统的模糊PI控制研究   总被引：1，自引：0，他引：1  

赵海波  周向红 《巢湖学院学报》2009,(3):71-75

在常规PI控制的基础上引入了模糊逻辑的概念,提出了一种模糊PI控制算法,采用模糊推理对PI调节器的控制参数进行在线调整.并用HATLAB中SIHULINK和FUZZY工具箱对三种控制方式进行了仿真.仿真结果表明,所提出的控制策略是有效的,使双电机良好的以一定速度同步运行.  相似文献   

A New Technique: Research and industrial application of a novel compound permanent magnet synchronous machine     

Cheng-zhi FAN  Ming-xing HUANG  Yun-yue YE 《浙江大学学报(A卷英文版)》2009,10(4)

We propose a novel kind of compound permanent magnet synchronous machine (CPMSM), which is applicable in low-speed and high-torque situations. We first explain the structure of the CPMSM. Based on theoretically deducing the calculation formulae of the CPMSM electromagnetic parameters, we analyze the operating characteristics of the CPMSM, and obtain the power-angle curves and working curves. The no-load magnetic field distribution and the cogging torque are analyzed by applying the finite element method of three-dimensional (3D) magnetic fields, to determine the no-load leakage coefficient and the wave0form of the cogging torque. Furthermore, the optimal parameters of the permanent magnet for reducing the cogging torque are determined. An important application target of the CPMSM is in direct-drive pumping units. We have installed and tested a directdrive pumping unit in an existing oil well. Test results show that the power consumption of the direct-drive pumping unit driven by CPMSM is 6 1. 1% of that of the beam-pumping unit, and that the floor space and weight are only 50% of those of a beam-pumping unit. The noise output does not exceed 58 dB in a range of 1 m around the machine when the machine is 1.5 m from the ground.  相似文献   

光谱法研究芦氟沙星与人血清白蛋白的相互作用     

邵爽 《浙江教育学院学报》2006,(6):47-52

用光谱法研究水溶液中芦氟沙星与人血清白蛋白的结合反应，分别测定了295，310K两个不同温度下二者的结合常数心和结合位点数n，探讨了其荧光猝灭机制；根据热力学参数确定了芦氟沙星与人血清白蛋白之间的作用力类型，以氢键或范德华力为主，并运用Foster偶极-偶极非辐射能量转移原理。测定了其相互结合时授．受体间的距离r；采用同步荧光技术考察确定芦氟沙星对人血清白蛋白构象产生一定的影响．  相似文献   

谈外语知识学习与技能学习的平衡发展     

栾金凤 《辽宁高职学报》2007,9(2):57-59

人类的学习是在社会活动中,以言语为中介,通过积极思维,主动掌握人类社会历史经验和积累个体经验的过程。对于学生来说,学习外语,不仅要掌握外语知识,而且要在掌握必要的语言知识的同时,熟练掌握运用外语进行交际的各种技能。也就是说,我们掌握一门外语,就是要掌握有关的知识和技能,使其平衡发展。  相似文献   

Position Sensorless Control for Permanent Magnet Synchronous Motor Using Sliding Mode Observer     

陈益广  傅涛李响 《天津大学学报(英文版)》2005,11(5):338-342

An approach of position sensorless control for permanent magnet synchronous motor （ PMSM ） is put forward based on a sliding mode observer. The mathematical model of PMSM in a stationary αβ reference frame is adopted, and the system is controlled by the digital signal processor （ DSP; TMS320LF2407 according to the control achieve closed loop operation of the motor, the stator theory of sliding mode observer. In order to magnetic field should be vertical with the rotor magnetic field and be synchronous with rotor rotating, so the position and speed of PMSM is estimated in real time and the estimated position is modified continuously. The simulation results indicate that the proposed observer has high precision is more robust to the parametric variation and load in estimation of PMSM position and speed, and torque disturbance.  相似文献   

同步整流技术在单端正/反激型DC-DC变流器应用电路研究     

高潮 《深圳信息职业技术学院学报》2006,4(1):13-16

对同步整流技术在单端正、反激型DC—DC变流器电路应用进行研究，基于如何减小低压大电流变换器的整流损耗，提高整流和转换效率，分析几种实际的单端正、反激型DC—DC同步整流变流器电路拓扑，阐述了其典型的整流电路工作原理、主要参数的设计方法，工作特点和开关工作波形。通过电路试验验证电路的实用性，有利于提高单端正、反激型DC—DC变流器的整流效率。  相似文献   

TPACK and Pre-Service Teacher Mathematics Education: Defining a Signature Pedagogy for Mathematics Education Using ICT and Based on the Metaphor “Mathematics Is a Language”     

《学校用计算机》2012,29(1-2):207-226

National professional standards for teachers in Australia (AITSL, 2011) expect teacher education graduates to demonstrate technological, pedagogical and content knowledge (TPACK). Those standards have emerged concurrently with the development of a new Australian mathematics curriculum. Thus, the expectation is that graduates can demonstrate the use of information and communication technologies in mathematics teaching and learning. The authors argue that “signature pedagogy” (Shulman, 2005 Shulman, L. S. 1986. Those who understand: Knowledge growth in teaching. Educational Researcher, 15(2): 4–14. [Crossref] , [Google Scholar]) is the use of a key metaphor which views mathematics as a language and suggests that mathematics should be taught and learned as any other language. This article provides a summary of the findings of an action research project involving two cohorts of undergraduate mathematics education students in an Australian university. Data collected was used to inform targeted changes to improve the technological pedagogical approach employed by the course team across two offers of the course to enhance student learning and align the course with the expectations for graduate teachers. The implications of this action research are provided to inform the design and implementation of pre-service teacher education courses with respect to the development of TPACK capabilities specifically in mathematics education.  相似文献   

活塞式空压机高压同步电机的变频节能改造     

郝须庆  任昌伟 《考试周刊》2012,(36)

针对空气压缩机在电解铝行业中的应用,提出对高压同步电机进行变频改造。  相似文献