中职《电子电工》教学中理实一体化的运用分析

随着社会的不断发展,职业教育与时俱进,新型的教育方式如雨后春笋般出现,如思维导图教学、沉浸阅读、翻转课堂教学等。其中,实践教学中最常用的便是理实一体化教学。该教学方法弥补了传统教学方式的不足,提高了教学水平。文章主要分析了在中职《电子电工》教学中如何运用理实一体化教学。

中职学校《电子电工技术》教学与学生创新能力的培养

随着我国教育事业的不断发展,教育不仅以理论知识为重,还将培养学生实验能力和创新能力放在了更重要的位置。培养学生的创新能力,是当今中职学校的重要教育内容。通过实验锻炼学生的技能,加强学生的动手能力,培养学生的创新能力,促进了教育的高效性。文章联系中职学校的实际情况,结合《电子电工技术》学科现状,讲述了如何培养学生的创新能力。

浅谈《电子电工基础》教学中学习兴趣的激发

教学的成功与否在很的程度上取决学生的学习主动性，而学习的主动性的高低则主要来自学习的兴趣。而学生一旦时学习皮生兴趣，就会充分发挥自己的积极性和主动性。学生只有对电工基础感兴趣，才能变“要我学”为“我要学”，从而学好《电子电工基础》。重视“绪论”课教学。加强直观教学，重视教学实验。利用多媒体计算机，制作模拟课件。创造良好的课堂情境。

高职院校《电工电子技术》课程在线教学的实践探索

高职院校的学生通过学习《电工电子技术》课程内容,有利于强化对基础知识的掌握,同时提高实践操作能力。为了获得更加显著的教学成效,学校及专业课教师应该提高对在线教学模式的重视,加强对教学改革相关政策内容的研究,强化与在线教学的融合,构建规范化、标准化的课程教学体系。因此,学校应该保证在线教学条件的全面性,如实现网络全覆盖、配置先进技术设备等,教师应该明确教学改革思路,编制科学完善的在线教学实践探索方案,加强不同教学环节的合理性设计,积极组织开展多元化的教学活动,形成一体化课程教学平台,从而达到提高《电工电子技术》教学效率的目的。

Comparative studies on hydrometallurgical treatment of smelted low-grade electronic scraps for selective copper recovery

A comparison of three hydrometallurgical methods for selective recovery of copper from low-grade electric and electronic wastes was reported. Scraps were smelted to produce Cu？Zn？Sn？Ag alloy. Multiphase material was analyzed by SEM？EDS and XRD. The alloy was dissolved anodically with simultaneous metal electrodeposition using ammoniacal and sulfuric acid solutions or leached in ammonia？ammonium sulfate solution and then copper electrowinning was carried out. This resulted in the separation of metals, where lead, silver and tin accumulated mainly in the slimes, while copper was transferred to the electrolyte and then recovered on the cathode. The best conditions of the alloy treatment were obtained in the sulfuric acid, where the final product was metal of high purity （99% Cu） at the current efficiency of 90%. Ammoniacal leaching of the alloy led to the accumulation of copper ions in the electrolyte and further metal electrowinning, but the rate of the spontaneous dissolution was low. Anodic dissolution of the alloy in the ammonia？ammonium sulfate solution led to the unfavorable distribution of metals among the slime, electrolyte and cathodic deposit.

Key techniques of symmetrical machining

To improve the machining efficiency of large symmetrical freeform surface, this paper proposes a new machining method： symmetrical machining （SM）. Based on the concept of collision avoidance plane （CAP）, collisions among cutters or headstocks are avoided, and the area of machining residue is controlled effectively. Machining residue is eliminated due to proper design of symmetrical tool in mechanism and control project. Taking 5-axis symmetrical machine with columnar headstocks and flat cutters as example, this paper proposes collision avoidance algorithm. Finally, using a twin-skeg ship model surface as an example, the method is applied to avoiding collisions in original tool path. Simulation and real machining results show that the scheme is practical. Furthermore, the machining efficiency of SM is improved 85% more than that of the traditional single cutter technology.

Electronic structure regulation on layered double hydroxides for oxygen evolution reaction

Oxygen evolution reactions(OERs)as core components of energy conversion and storage technology systems,such as water splitting and rechargeable metal–air batteries,have attracted considerable attention in recent years.Transition metal compounds,particularly layered double hydroxides(LDHs),are considered as the most promising electrocatalysts owing to their unique two-dimensional layer structures and tunable components.However,heir poor intrinsic electrical conductivities and the limited number of active sites hinder their performances.The regulation of the electronic structure is an effective approach to improve the OER activity of LDHs,including cationic and anionic regulation,defect engineering,regulation of intercalated anions,and surface modifications.In this review,we summarize recent advances in the regulation of the electronic structures of LDHs used as electrocatalysts in OERs.In addition,we discuss the effects of each regulation type on OER activities.This review is expected to shed light on the development and design of effective OER electrocatalysts by summarizing various electronic structure regulation pathways and the effects on their catalytic performances.

An Investigation on Telecommunication Staff＇s Acceptance of E-Learning Technology

As the information on telecommunication products updates rapidly, using E-learning in staff training becomes an edge for company operation. However, previous studies showed that staff＇s attitude toward E-learning significantly affected the outcomes of training. The purpose of this study is to investigate the acceptance of E-learning in a telecommunication company. The researchers adopted the technology acceptance model （TAM） and diffusion of innovation theory to evaluate the perceived usefulness and perceived ease of use on E-learning, in addition to employees＇ self-directed learning motivation, attitude toward computers, and organizational influence. We randomly chose 571 employees of the telecommunication entrepreneur at the Taichung office in Taiwan to participate in this survey. The result showed that employees＇ background factors such as age, job position, marital status, education level and the scale of job unit had the significant impact on behavioral intention to use E-learning. Employees＇ self-directed learning, attitude toward computers, and organizational influence respectively also had positive effects on perceived usefulness of E-learning and perceived ease of use of E-learning. Furthermore, employees＇ perceived usefulness of E-learning and perceived ease of use of E-learning also had a positive effect on behavioral intention to use E-learning systems.

Self-supporting NiFe LDH-MoS_(x) integrated electrode for highly efficient water splitting at the industrial electrolysis conditions

Developing effective and practical electrocatalyst under industrial electrolysis conditions is critical for renewable hydrogen production.Herein,we report the self-supporting NiFe LDH-MoS_(x) integrated electrode for water oxidation under normal alkaline test condition(1 M KOH at 25℃)and simulated industrial electrolysis conditions(5 M KOH at 65℃).Such optimized electrode exhibits excellent oxygen evolution reaction(OER)performance with overpotential of 195 and 290 mV at current density of 100 and 400 mA·cm^(-2) under normal alkaline test condition.Notably,only over-potential of 156 and 201 mV were required to achieve the current density of 100 and 400mA·cm^(-2) under simulated industrial electrolysis conditions.No significant degradations were observed after long-term durability tests for both conditions.When using in two-electrode system,the operational voltages of 1.44 and 1.72 V were required to achieve a current density of 10 and 100 mA·cm^(-2) for the overall water splitting test(NiFe LDH-MoS_(x)/INF||20%Pt/C).Additionally,the operational voltage of employing NiFe LDH-MoS_(x)/INF as both cathode and anode merely require 1.52 V at 50mA·cm^(-2) at simulated industrial electrolysis conditions.Notably,a membrane electrode assembly(MEA)for anion exchange membrane water electrolysis(AEMWEs)using NiFe LDH-MoS_(x)/INF as an anode catalyst exhibited an energy conversion efficiency of 71.8%at current density of 400 mA·cm^(-2)in 1 M KOH at 60℃.Further experimental results reveal that sulfurized substrate not only improved the conductivity of NiFe LDH,but also regulated its electronic configurations and atomic composition,leading to the excellent activity.The easy-obtained and cost-effective integrated electrodes are expected to meet the large-scale application of industrial water electrolysis.

Analysis on the Application of Electrical New Technology of in Electromechanical Integration

The electrical new technology is a new frontier science.This kind of technology, with the development and progress of society, makes the continuous development and innovation.It is the future development trend of electrical engineering system,which plays a very important role in technological innovation.The principle and theoretical support for the development of electrical new technology includes Bio- electro magnetics, plasma physics, electromagnetic fluid mechanics and gas discharge physics etc.In addition, under the application of permanent magnetic materials and other new materials, the electrical new technology and obtained further development also promote the development and application of electronic power supply, strong magnetic field technology, solar photovoltaic power generation, and superconducting power technology.This paper mainly analyzes the application of electrical new technology in electromechanical integration.

Process engineering in electrochemical energy devices innovation

This review focuses on the application of process engineering in electrochemical energy conversion and storage devices innovation. For polymer electrolyte based devices, it highlights that a strategic simple switch from proton exchange membranes(PEMs) to hydroxide exchange membranes(HEMs) may lead to a new-generation of affordable electrochemical energy devices including fuel cells, electrolyzers, and solar hydrogen generators. For lithium-ion batteries, a series of advancements in design and chemistry are required for electric vehicle and energy storage applications. Manufacturing process development and optimization of the LiF eP O_4/C cathode materials and several emerging novel anode materials are also discussed using the authors' work as examples.Design and manufacturing process of lithium-ion battery electrodes are introduced in detail, and modeling and optimization of large-scale lithium-ion batteries are also presented. Electrochemical energy materials and device innovations can be further prompted by better understanding of the fundamental transport phenomena involved in unit operations.

Research of micro-EDM and its applications

A Micro Electrical Discharge Machining (MEDM) equipment was developed in this paper,on which the CNC interpolation for 3-axis linkage movement could be realized easily. By this micro-EDM equipment,the fabrication process of microelectrode,micro hole,silicon wafer and complex microstructure was discussed. The process rules of machining efficiency and the relative electrode wear rate as well as the machining mechanism and performance of silicon micro-EDM were also researched. Machining experiments showed that the microelectrode diameter as small as 6 μm and the micro hole with minimum size of 10 μm could be obtained steadily,and the maximum aspect ratios of microelectrode and micro hole were over 25 and 10 respectively. And silicon micro-EDM experiments showed that the micro beam with the aspect ratios over 15 could be obtained easily. And a micro beam with minimum size of 23 μm width on a silicon wafer with 420 μm thickness was achieved. At last,the microstructure machining technology for micro-EDM was also discussed. And a micro-facial sculpture with free space curved surface and size of 1 mm×0.3 mm×0.18 mm was also machined successfully.

Metacognition in Solving Process of Basic Electric Circuit ProblemmComparison of Metacognitive Characteristics between Non-major and Major Students in Electric Engineering

There are learners who cannot solve practical problems in spite of mastering basic scientific knowledge and formula necessary for the solution. One of the reasons might be attributed to the lack in metacognitive abilities. The aim of this study was to compare the metacognitive characteristics between non-major and major students in electric engineering and clarify the difference of metacognitive process between these two groups when solving basic problems of electronic circuit. In the experiment, the solving process was compared between non-major and major students in electric engineering using five basic problems. We found that the scores on prediction of result and confidence of own answer differed significantly between non-major and major students, and inferred that the difference of performance was due to the lack in metacognitive ability, especially the plan and the execution abilities. Both prediction of results and confidence of own answer were also found to play a significant role in effective problem solving as important components （subsystems） of metacognition.

Personalization on the TV on Demand

The Interactive Intemet TV Project is intended to be a web tool for publishing, indexing and viewing videos; that offers ontology based recommendations. The application has been developed and tested as a platform for e-learning in a univerasity context and in Optiva Media Company. It combines expertise in education and television to develop a prototype,., where the contents are generated using an automatic recommendation model based on personal profiles of each user; and that can be accessed from different devices： computers, mobile phones and so on.

An Advanced Teaching Lab for the Setting up of an Islanded Production Unit

The present paper addresses an advanced teaching lab consisting of setting up an islanded production unit. This teaching lab takes place in the very last semester at master level for students in electrical engineering with energy specialization. The purpose of this teaching lab is to combine knowledge learned in different areas such as power electronics, control, electrical machines and networks, and make use of all of them in practice. The present paper describes in detail the different steps followed by the student to set up an islanded production unit.

Development of a Small Scale Magnetically Levitated Train as Demonstrator for Undergraduate Mechatronics Students

At the Institute of Electrical Machines of the Rheinisch Westfalilische Technische Hochschule Aachen University, there is a project financed by student fees for the realization of a magnetically levitated train in the scale of 1：50. Undergraduate students are supposed to get the possibility to design and build up a real train which serves as demonstrator for a mechatronic system. This project strengthens the motivation of students, since a practical demonstration of electromagnetic forces is given in addition to theoretical courses. This paper introduces the major project steps and explains the learning targets for the students. It focuses on analytical magnetic circuit design, numerical field simulation, modeling and control of a multi degree of freedom system, electronic circuit design, measurement setups and a first prototype test bench.

Softening interstage annealing of austenitic stainless steel sheets for stamping processes

To study the mechanics of work-hardening and annealing-softening, a series of experiments were conducted on samples of 304 austenitic stainless steel sheets. In addition, transmission electron microscopy （TEM）, scanning electron microscopy （SEM）, and tensile testing were carried out to study changes and mechanisms of the stainless steel structures and properties during work-hardening and annealing-softening. The results indicate that annealing at low temperatures （100-500 ~C） can only remove partial residual stresses in the sample and the softening via annealing is not obvious. Bright annealing and rapid cooling in a protective atmosphere can completely soften the cold-worked material. In addition, the low-temperature sample without a protective atmosphere only has a little oxidation on the surface, but at higher temperature the oxidized layer is very thick. Thus, high-temperature annealing should include bright annealing.

One-pot synthesis of Li_3VO_4@C nanofibers by electrospinning with enhanced electrochemical performance for lithium-ion batteries

Electrospinning is firstly used to one-pot synthesis of Li3VO4@C nanofibers in a large scale. Although with the presence of organic sources in synthesis process, the pure phase Li3VO4 with superior nanofibrous morphology is still successfully obtained through adjusting different heat treatment processes and different vanadium sources. The prepared Li3VO4@C nanofibers exhibit a unique structure in which nanosized Li3VO4 particles are uniformly embedded in amorphous carbon matrix. Compared with LiBVO4/C powder, Li3VO4@C nanofibers display enhanced reversible capacity of 451 mAhg^-1 at 40mAg^-1 with an increased initial coulombic efficiency of 82.3%, and the capacity can remain at 394 mAh g ^-1 after 100 cycles. This superior electrochemical performance can be attributed to its unique structure which ensures a high reactivity by nanosized Li3VO4, more stable electrode/electrolyte interface by carbon encapsulation, improved electronic conductivity and buffered volume changes by flexible carbon matrix. The electrospinning technology provides an effective method to obtain high performance Li3VO4 as a promising anode material for lithium-ion batteries.

An experimental research on single discharge machining of insulating ceramics efficiently with high energy capacitor

Insulating ceramics are applied to modern manufacturing industries for their improved material properties.But they are the difficult-to-machine materials because of their high rigidity,high brittleness and non-electrical conductivity.A new method which employs a high energy capacitor for electric discharge machining of insulating ceramics efficiently is presented in this paper,and the single discharge experiments have been carried out.The process uses the high voltage,large capacitor and high discharge energy,it is able to effectively machine insulating ceramics,and the single discharge crater volume of insulating ceramics can reach 17.63 mm3.The effects of polarity,peak voltage,capacitance,current-limiting resistance,tool electrode feed,tool electrode section area and assisting electrode thickness on the process performance such as the single discharge crater volume,the tool wear ratio and the assisting electrode wear ratio have been investigated.The microstructure of the discharge crater is examined with a scanning electron microscope(SEM).The results show that the discharge craters have sputtering appearance,the insulating ceramic materials are mostly removed by spalling,in the center region of the discharge some materials are removed by melting and vaporization,and the material removal is enhanced with the machining parameters increasing.

Low-power high-mobility organic single-crystal field-effect transistor

Evolving flexible electronics requires the development of high-mobility and low-power organic field-effect transistors(OFETs)that are crucial for emerging displays,sensors,and label technologies.Among diverse materials,polymer gate dielectrics and two-dimensional(2D)organic crystals have intrinsic flexibility and natural compatibility with each other for OFETs with high performance;however,their combination lacks non-impurity and non-damage construction strategies.In this study,we developed a desirable OFET system using damage-free transfer of 2D organic single crystal,dinaphtho[2,3-b:2',3'-f]thieno[3,2-b]thiophene on a unique polymer dielectric layer,poly(amic acid)(PAA).Benefiting from the unique PAA surface nanostructure and the long-range ordered characteristics of the 2D organic single crystal,the resulting OFETs show remarkable performance with high mobility and low operating voltage of 18.7 cm^(2) V^(−1) s^(−1) and−3 V,respectively.The result indicates that combining polymer gate dielectric with 2D organic single crystal using a high-quality method can produce flexible electronic devices with high performance.