Topological domains/domain walls and broken symmetries in multiferroics     

Sang-Wook Cheong 《国家科学评论(英文版)》2019,6(4):624

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Assessment,Grade Level and Learning     

Agnes Chang Shook Cheong 《Asia Pacific Journal of Education》1992,12(2):35-47

Researchers have identified assessment as a very crucial influence on the learning strategies adopted by students. The present study carried out on Secondary 2, Secondary 4, and Junior College 2/Pre-University 3 students shows that the Singapore students did not favour the Surface Approach in their learning of English and Mathematics. The nature of the discipline and the cognitive demands of the examinations carried considerable importance for students in their choice of learning strategies. Despite the heavy emphasis on excelling in examinations, students did not rely solely on surface and achieving strategies to attain their goals.  相似文献   

Research on Educational Media: Half a Century of Doing Things Right Rather Than the Right Thing     

Lau Kam Cheong 《Asia Pacific Journal of Education》1989,10(1):10-18

This paper critically examines research on the influence of educational media on learning. It argues that much of the supposed benefits of media such as greater concreteness, improved learning performance, more efficient learning and increased retention, among others, are not supported by the evidence thus far. Comparative research on different forms of media, and on media attributes have likewise proved inconclusive. The paper goes on to explore reasons for these findings and urges that future studies should focus on studies with media rather than on media.  相似文献   

Informed learning design: teaching and learning through engagement with information     

Clarence Maybee  Christine Susan Bruce  Mandy Lupton  Ming Fai Pang 《高等教育研究与发展》2019,38(3):579-593

ABSTRACT

While higher education teachers are able to use information in sophisticated ways to learn and communicate within their disciplines, they may not be accustomed to teaching their students to use information creatively and reflectively to support their work in a course. This article introduces informed learning design, a curriculum design model by which teachers specifically enable students to learn course content through intentional engagement with information. Drawing from informed learning pedagogy and the variation theory of learning, the design model outlines an instructional pattern for enabling student awareness of critical aspects and features of the object being studied related to both information use and course content.  相似文献   

Dynamics and manipulation of ferroelectric domain walls in bismuth ferrite thin films     

Shuyu Xiao  Yaming Jin  Xiaomei Lu  Sang-Wook Cheong  Jiangyu Li  Yang Li  Fengzhen Huang  Jinsong Zhu 《国家科学评论(英文版)》2020,7(2):278

Ferroelectric domain walls differ from domains not only in their crystalline and discrete symmetry, but also in their electronic, magnetic, and mechanical properties. Although domain walls provide a degree of freedom to regulate the physical properties at the nanoscale, the relatively lower controllability prevents their practical applications in nano-devices. In this work, with the advantages of 3D domain configuration detection based on piezoresponse force microscopy, we find that the mobility of three types of domain walls (tail-to-tail, head-to-tail, head-to-head) in (001) BiFeO₃ films varies with the applied electrical field. Under low voltages, head-to-tail domain walls are more mobile than other domain walls, while, under high voltages, tail-to-tail domain walls become rather active and possess relatively long average lengths. This is due to the high nucleation energy and relatively low growth energy for charged domain walls. Finally, we demonstrate the manipulation of domain walls through successive electric writings, resulting in well-aligned conduction paths as designed, paving the way for their application in advanced spintronic, memory and communication nano-devices.  相似文献   

Data Integrity and Reconstruction: On the Planning, Development and Future of the Modern Chinese Literature Research Portal     

Ma Fai Hung Leo  Chan Chi Tak  Long Xiang yang  Wong Pun Ming Chu Rita 《大学图书馆学报》2008,26(6)

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Electroosmotic flow hysteresis for dissimilar ionic solutions     

An Eng Lim  Chun Yee Lim  Yee Cheong Lam 《Biomicrofluidics》2015,9(2)

Electroosmotic flow (EOF) with two or more fluids is commonly encountered in various microfluidics applications. However, no investigation has hitherto been conducted to investigate the hysteretic or flow direction-dependent behavior during the displacement flow of solutions with dissimilar ionic species. In this investigation, electroosmotic displacement flow involving dissimilar ionic solutions was studied experimentally through a current monitoring method and numerically through finite element simulations. The flow hysteresis can be characterized by the turning and displacement times; turning time refers to the abrupt gradient change of current-time curve while displacement time is the time for one solution to completely displace the other solution. Both experimental and simulation results illustrate that the turning and displacement times for a particular solution pair can be directional-dependent, indicating that the flow conditions in the microchannel are not the same in the two different flow directions. The mechanics of EOF hysteresis was elucidated through the theoretical model which includes the ionic mobility of each species, a major governing parameter. Two distinct mechanics have been identified as the causes for the EOF hysteresis involving dissimilar ionic solutions: the widening/sharpening effect of interfacial region between the two solutions and the difference in ion concentration distributions (and thus average zeta potentials) in different flow directions. The outcome of this investigation contributes to the fundamental understanding of flow behavior in microfluidic systems involving solution pair with dissimilar ionic species.  相似文献   

Lessons from TIMSS in Europe: An Observation from Asia     

Yin Cheong Cheng  Wing Ming Cheung 《Educational Research and Evaluation》2013,19(2):227-236

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Accuracy of Estimates and Statistical Power for Testing Meditation in Latent Growth Curve Modeling     

JeeWon Cheong 《Structural equation modeling》2013,20(2):195-211

The latent growth curve modeling (LGCM) approach has been increasingly utilized to investigate longitudinal mediation. However, little is known about the accuracy of the estimates and statistical power when mediation is evaluated in the LGCM framework. A simulation study was conducted to address these issues under various conditions including sample size, effect size of mediated effect, number of measurement occasions, and R ₂ of measured variables. In general, the results showed that relatively large samples were needed to accurately estimate the mediated effects and to have adequate statistical power, when testing mediation in the LGCM framework. Guidelines for designing studies to examine longitudinal mediation and ways to improve the accuracy of the estimates and statistical power were discussed.  相似文献   

Spreadsheet Modeling of Equipment Acquisition Plans     

Thin-Yin Leong  Michelle L. F. Cheong 《Decision Sciences Journal of Innovative Education》2008,6(2):365-373

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