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CUHK electronic theses & dissertations collection
No full textChu, Ming Hon.Thesis M.Phil. Chinese University of Hong Kong 2014.Includes bibliographical references (leaves 159-163).Abstracts also in Chinese.Title from PDF title page (viewed on 20, September, 2016)
The development and implementation of a marketing decision support system.
Get PDFby Chan Kok-Wing, Chu Ming-Cheung.Thesis (M.B.A.)--Chinese University of Hong Kong, 1985.Bibliography: leaves 100-102
Boron nitride thin films deposited by magnetron sputtering on Si3N4
Get PDFMestrado em Ciência e Engenharia de MateriaisO Nitreto de boro é um material polimorfo, sendo as fases hexagonal (h-BN) ecúbicas (c-BN) as predominantes. A fase hexagonal do nitreto de boro apresenta uma estrutura em camadas sp2, semelhante a grafite, enquanto que a fase cúbica do nitreto de boro tem forte ligações sp3, como o diamante. O h-
BN apresenta boas propriedades dieléctricas, é um material refractário, resistente a corrosão, é conhecido por ser um lubrificante sólido que tem
aplicações na protecção de moldes de injecção e em outros processos mecânicos de elevadas temperaturas ou lubrificação em ambientes de elevada humidade. Contudo, o h-BN é extremamente macio. Em contraste, o c-BN
apresenta excelentes propriedades térmicas, eléctricas e ópticas, sendo ainda um dos materiais conhecidos com dureza mais elevada (70 GPa). Além disso, c-BN apresenta propriedades superiores em relação ao diamante quando
aplicado em ferramentas de corte na maquinagem de materiais ferrosos, devido a sua alta estabilidade química a altas temperaturas durante a
maquinagem. Essa combinação de propriedades faz dele um forte candidato no campo das ferramentas de corte e em dipositivos electrónicos. No presente trabalho, filmes finos de nitreto de boro foram depositados por DC e RF magnetron sputtering, utilizando alvos de B4C e h-BN prensados a quente, numa atmosfera de deposição contituída por misturas de Ar e N2. Os filmes
finos de BN foram depositados simultâneamente em dois tipos de substratos:
cerâmicos de Si3N4 com diferentes acabamentos superficiais e em discos de Si(100). A influência dos parâmetros de deposição, tais como a temperatura
do substrato, composição da atmosfera de deposição na espessura dos filmes, taxa de deposição, cristalinidade, tensão residual, fases presentes e dureza, foram sistematicamente investigados usando técnicas como, SEM, XRD, FT-IR e nanodureza. O h-BN foi a principal fase observada nas análises dos espectros de FT-IR e nos difractogramas de XRD. O estado de tensão dos filmes finos de BN films é estremamente afectado pela temperatura do substrato, composição do gás de trabalho e pelo acabamento superficial dos substratos. O estudo da influência da temperatura mostraram que a taxa de
deposição aumenta com o aumento da temperatura do substrato. Tensões residuais elevadas ocorrem para altas concentrações de árgon e para
substratos polidos em suspensão de diamante 15 μm. Nos espectros de FT-IR, a forma das bandas de vibração variam de uma forma alargada para uma configuração estreita, correspondendo a uma menor desordem da fase hexagonal do BN, devido a variação da composição da atmosfera de
deposição. Os valores de dureza obtidos estão numa faixa que vai desde os valores do h-BN macio (6 GPa) até valores próximos dos limites encontrados para filmes contendo a fase cúbica (16 GPa ), acima de 40%.
ABSTRACT: Boron nitride is a polymorphic material, the hexagonal (h-BN) and the cubic (c- BN) being its main crystalline structure. The hexagonal boron nitride has a layered sp2-bonded structure, similar to graphite, while the cubic boron nitride has a hard sp3-bonded diamond-like structure. h-BN presents good dielectric properties, refractoriness, corrosion-resistant characteristics, low friction and
low wear rate, and it is a well-known solid lubricant which has wide applications in metal-forming dies and other metal working processes at high temperatures or lubrication in high relative humidity environments. However, h-BN is mechanically soft. In contrast, c-BN presents excellent thermal, electrical and optical properties, with a hardness up to 70 GPa. Moreover, c-BN is superior to
diamond as cutting tool for ferrous materials due to its high thermal chemical stability during machining. In the present work, thin films of boron nitride have
been deposited by D.C. and R.F. magnetron sputtering from hot-pressed B4C and h-BN targets, using mixtures of Ar and N2, as working gases. The BN thin films were deposited simultaneously on two different substrates: Si3N4 ceramics with different surface finishing and Si(100) wafers. The influence of parameters such as substrate temperature and working gas composition ratio, on film thickness, deposition rate, cristallinity, residual stress, phase
composition and hardness, were systematically investigated using techniques like SEM, XRD, FT-IR and nanohardness. h-BN was the main observed phase. The stress-state of the thin BN films is largely affected by the substrate
temperature, working gas composition and the substrate surface finishing. The substrate temperature studies show that the deposition rate increases with an increasing of the substrate temperature. Large high residual stresses are
developed for higher argon ratios and for substrate finishing with 15 μm diamond paste. In the FT-IR spectra, the shape of the vibration band changes
from broad to narrow, corresponding to a less disorder h-BN phase, due to the working gas composition. The hardness values obtained are typical in the range of a soft h-BN (6 GPa) to values approaching the limit of the range reported for films containing a fraction of cubic phase (16 GPa ) up to 40%
American and European news coverage and analysis of the Sept.11 event and the Afghan war — lessons for Taiwan
No full textBook review. Technology Transfer between the US, China and Taiwan: Moving Knowledge. Edited by Douglas B. Fuller and Murray A. Rubinstein. London and New York: Routledge,2013. x + 181 pp. £85.00; $145.00. ISBN 978-0-415-64220-0
No full textNo need to beg China? Taiwan’s membership of the Asia-Pacific Economic Cooperation as a contested state
Get PDFThis article examines the process, causes and repercussions of the accession of Taiwan, as a contested state, together with China, to the Asia-Pacific Economic Cooperation in 1991, the first intergovernmental organization that Taipei has joined since 1971. Based on an analysis of elite interviews, primary and secondary data, the paper traces the under-explored diplomatic history of the accession. It argues that changes in Taiwan's domestic and external environments, as well as changes in the diplomatic process, account for Taipei's admission, rather than the China factor alone. The paper examines four positive effects of accession on Taiwan's international space and the implications for Taiwan's continuous survival as a contested state. By undertaking a nuanced analysis of an important yet little explored milestone in the contested state's struggle to mitigate its international isolation, the article sheds light on Taiwan's external ties against the backdrop of the sovereignty dispute between Taipei and Beijing
China’s defence semiconductor industrial base in an age of globalisation: cross-strait dynamics and regional security implications
No full textThe globalisation of semiconductor production has helped China improve its defence microelectronics capability. By analysing primary and secondary data, this paper examines semiconductor globalisation across the Taiwan Strait and shows the flow of resources from Taiwan to its Chinese counterparts linked to the People’s Liberation Army (PLA). This flow of resources has improved the PLA’s capabilities, including for Trojan Horse attacks, and affected security dynamics in the Sino-US-Taiwan relationship. This paper sheds fresh light on an understudied aspect of PLA modernisation and contributes to the study of the globalisation-security nexus and pertinent policy debates.</p
China's ambitions in the semiconductor sphere and Taiwan's dilemma
No full textThe semiconductor industry is a vital industry for military establishments worldwide, and the control of, or loss of control of, this key industry has enormous strategic implications. This op-ed outlines China’s motivations to enhance its domestic semiconductor capability because of national security considerations and argues that Chinese semiconductor firms’ recent merger and acquisition (M&A) activities targeting the U.S. and Taiwanese companies should be examined in the context outlined. Based on my research fieldwork that culminated in over 160 elite interviews as of 2009, I argue that the Taiwanese contributions to China’s nascent semiconductor industry have permeated through integrated circuit (IC) design, fabrication, packaging and testing subsectors of the industry through trans-border transfers of technology, human resources and investment especially since 2000. This process of sectoral production globalization, in turn, has resulted in economic and security ramifications for Taiwan. Against this backdrop, Taiwan’s President-elect Tsai Ing-wen will be faced with a major dilemma after she takes office on 20 May in determining whether the Chinese M&A applications should be permitted to go ahead. Such dilemma becomes exacerbated when the Chinese M&A ambitions start to target high-end firms in the semiconductor supply chain, given the national security concerns involved
Contrôler l’incontrôlable: la délocalisation de l’industrie taiwanaise des semi-conducteurs vers la Chine et ses implications pour la sécurité
No full textCet article présente les résultats préliminaires d’une étude de cas qui explore le lien entre mondialisation et sécurité. En adoptant une approche « élargie » et multidisciplinaire, nous analyserons les aspects stratégiques de la délocalisation de l’industrie des semi-conducteurs vers la Chine, phénomène qui s’inscrit dans le processus de mondialisation actuelle. Sur la base d’entretiens et de données secondaires, nous explorerons les motivations de cette migration ainsi que les moyens par lesquels les entrepreneurs taiwanais contournent et violent la réglementation taiwanaise en vigueur. Nous avancerons que ces activités, motivées par le profit, aboutissent à l’émergence de toutes sortes de défis stratégiques pour Taiwan et pour les États-Unis dans les domaines de la sécurité technologique et de la sécurité de défense
The East Asian computer chip war
No full textThe semiconductor industry is a vital industry for military establishments worldwide, and the control of, or loss of control of, this key industry has enormous strategic implications. This book focuses on the globalization of the strategic semiconductor industry and the security ramifications of this process. It examines in particular the migration of the Taiwanese chip industry to China as part of the globalization of production processes, and the extent to which such a globalization process poses security challenges to the United States, China and Taiwan. Transcending disciplinary boundaries between international political economy, security studies, and the history of science and technology, this multidisciplinary work provides an in-depth understanding of the globalization-security nexus, and disentangles the key policy issues connected to a potential explosive flashpoint in world politics today
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