71,596 research outputs found
Ji ben li zi wu li xue de yan jiu
No full textTsui, Ka Ming = 基本粒子物理學的研究 / 徐嘉明.Thesis M.Phil. Chinese University of Hong Kong 2015.Includes bibliographical references (leaves 150-157).Abstracts also in Chinese.Title from PDF title page (viewed on 03, January, 2017).Tsui, Ka Ming = Ji ben li zi wu li xue de yan jiu / Xu Jiaming
Duo dian xie zuo: gan rao jian qing yu gan rao li yong
No full textShen, Siduo.Thesis Ph.D. Chinese University of Hong Kong 2014.Includes bibliographical references (leaves 147-161).Abstracts also in Chinese.Title from PDF title page (viewed on 15 September, 2016).Shen, Siduo = Duo dian xie zuo : gan rao jian qing yu gan rao li yong / Shen, Siduo
Intentionally Carbon-Doped AlGaN/GaN HEMTs:Necessity for Vertical Leakage Paths
No full textDynamic ON-resistance (RON) in heavily carbon doped AlGaN/GaN high electron mobility transistors is shown to be associated with the semi-insulating carbon-doped buffer region. Using transient substrate bias, differences in RON dispersion between transistors fabricated on nominally identical epilayer structures were found to be due to the band-to-band leakage resistance between the buffer and the 2DEG. Contrary to normal expectations, suppression of dynamic RON dispersion in these devices requires a high density of active defects to increase reverse leakage current through the depletion region allowing the floating weakly p-type buffer to remain in equilibrium with the 2DEG
Analysis of microstructures and defects of GaN grown on sapphire substrates
No full textThe study aims at investigating the microstructures of GaN grown on sapphire substrate, including the interface between GaN and substrate as well as the InGaN/GaN multi quantum well (MQW) in GaN film. Some tiny straight lines on the surface of GaN film produced from epitaxy process can be observed by optical microscope. The scanning electron microscope (SEM) and transmission electron microscope (TEM) were used to analyze the lines. When analyzing the GaN film, we discovered some V-shape defects in the InGaN/GaN and above which the roughening hollows corresponded to the defects. Therefore, we used Cathodoluminescence and TEM to further analyze the influence of V-shape defects on the growth of GaN film
Fei xian xing jie zhi he wai jia jing tai ci chang dui biao mian deng li zi se san guan xi de ying xiang
No full textLi, Ming Yip = 非線性介質和外加靜態磁場對表面等離子色散關係的影響 / 李銘業.Thesis M.Phil. Chinese University of Hong Kong 2014.Includes bibliographical references (leaves 88-91).Abstracts also in Chinese.Title from PDF title page (viewed on 01, November, 2016).Li, Ming Yip = Fei xian xing jie zhi he wai jia jing tai ci chang dui biao mian deng li zi se san guan xi de ying xiang / Li Mingye
AlN/GaN-based MOS-HEMT technology: processing and device results
No full textProcess development of AlN/GaN MOS-HEMTs is presented, along with issues and problems concerning the fabrication processes. The developed technology uses thermally grown Al<sub>2</sub>O<sub>3</sub> as a gate dielectric and surface passivation for devices. Significant improvement in device performance was observed using the following techniques: (1) Ohmic contact optimisation using Al wet etch prior to Ohmic metal deposition and (2) mesa sidewall passivation. DC and RF performance of the fabricated devices will be presented and discussed in this paper
Growth of free-standing non-polar GaN on LiAlO2 substrates by Hydride Vapor Phase Epitaxy
No full textA hydride vapor phase epitaxy, (HVPE) was designed to grow nonpolar GaN. LiAlO2 single crystal grown by Czochralski (Cz) method in our lab was used as the substrate. The X-ray diffraction and scanning electron microscopy were used to study the GaN epilayer\ue2s orientation and surface morphology. At the first part, we used the c-plane sapphire as substrate and make sure that our HVPE reactive system is working. And the second part, we used LiAlO2 substrate to grow non-polar GaN substrate. After the growth, GaN was separated from LiAlO2 substrate and become free-standing. We found that as-grown GaN has both c-plane (0001) and m-plane (10-10) orientations. After some improvements, we got a nonpolar GaN substrate. But the m-plane (10-10) GaN grains are random. The photo-luminescence\uef\ubcPL\uef\ubcshowed that the light emissive quality of these two GaN thick film are well. We will keep improving the design of our HVPE
The politics of fashion: perceptions of power in female clothing and ornamentation as reflected in the sixteenth-century Chinese novel Jin Ping Mei
No full textThis thesis examines issues of female power and influence in sixteenth-century China focusing on how women and their roles were perceived in the changing social environment of the mid-late Ming dynasty. Using aspects of a New Historicist approach, information from contemporary literary and historical sources are analysed alongside each other. With its emphasis on the lives of women and preoccupation with the description of material objects, the late Ming novel Jin Ping Mei forms an important element in the thesis. China in the sixteenth century saw expanding urbanisation, the emergence of a new wealthy merchant class, increasing visibility of women and a questioning of traditional morality. Fashion consciousness, as one of the most conspicuous aspects of the new material culture, is a possible indicator of these trends. Traditional Western theories contend that fashion began in the particular context of Renaissance Europe. However, this study argues that a similar fashion awareness existed in China too, and was manifested in a competitive striving for social status, in this case specifically among women. In contrast to previous studies which downplayed the impact women had on defining traditional Chinese culture, this thesis demonstrates how women and their sartorial choices began to redefine the boundaries of material culture, influencing literati discourse which, in turn, re- influenced female behaviour
Chao leng xuan liang hun he wu zhong de yi he jian xiang gan zi xuan dong li xue
No full textLi, Xiaoke = 超冷旋量混合物中的異核間相干自旋動力學 / 李小科.Thesis Ph.D. Chinese University of Hong Kong 2015.Includes bibliographical references (leaves 126-142).Abstracts also in Chinese.Title from PDF title page (viewed on 25, October, 2016).Li, Xiaoke = Chao leng xuan liang hun he wu zhong de yi he jian xiang gan zi xuan dong li xue / Li Xiaoke
Study on surface morphology of GaN growth by MOCVD on GaN/Si(111) template
No full textThe surface morphology of GaN grown by MOCVD on GaN/Si template was studied. Rough morphology and deep pinhole defects on some surface areas of the samples were observed and studied. The formation of rough morphology is possibly related to Ga-Si alloy produced due to poor thermal stability of template at high temperature. The deep pinhole defects generated are deep down to the surface of MBE-grown GaN/Si template. The stress originated from the large thermal expansion coefficient difference between GaN and Si may be related to the formation of the pinhole defects. The surface morphology of the GaN can be improved by optimizing the GaN/Si template and decreasing the growth temperature
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