172 research outputs found
Cold Spray Coatings for Surface Enhancement of Inconel 718
No full textCold spray is an emerging additive manufacturing technology that is promising to be used for surface repair and enhancement. In this study, Inconel 713 coating was successfully deposited on Inconel 718 substrate using a high-pressure cold spray process. The microstructure and hardness of the coating were studied. The cold sprayed Inconel 713 coating had a very low porosity level due to the severe plastic deformation of the splats. Hardness of the coating is much higher than that of Inconel 718 substrate. The regions closer to the substrate-coating interface in the coating showed higher hardness value compared to those located further away from the interface. This phenomenon can be attributed to the peening effect during high-velocity impact of Inconel 713 particles with the Inconel 718 substrate. This study demonstrates that cold sprayed coatings have the potential to increase surface hardness and further improve wear resistance of the Inconel 718 substrate
Inconel 713C Coating by Cold Spray for Surface Enhancement of Inconel 718
No full textInconel 713C is a nickel-based superalloy usually considered as a material of poor weldability due to its susceptibility to hot cracking in the heat-affected zones. Cold spray, a solid-state deposition technology that does not involve melting, can be proposed as a methodology to deposit Inconel 713C for surface enhancement of other target components. In this study, Inconel 713C coating was deposited on Inconel 718 substrate with a high-pressure cold spray system. The coating was characterized in terms of microstructure, hardness, and wear properties. The cold-sprayed Inconel 713C coating has a low porosity level and refined grain structures. Microhardness of the Inconel 713C coating was much higher than the Inconel 718 substrate. The sliding wear tests showed that the wear resistance of the cold-sprayed Inconel 713C coating is three times higher than the Inconel 718 substrate, making the coating a suitable protective layer. The main wear mechanisms of the coating include oxidation, tribo-film formation, and adhesive wear
NIE Family Day 2014 (3 Oct 2014)
No full textThe Staff Welfare Recreation Fund Committee (SWRFC) Organizing Committee of Family Day. Back row, from left: Lee Li Lian Val (NSSE), Nenny Noorman (LIBRIS), Kristina Burgetova (PS), Ho Yen Yen Rebecca (NSSE), Low Li Jia (OAAS), Soo Li Mei Johannah (NSSE), Lim-Ang Ah Buan (NSSE) and Stevenson-Yong Mary Magdalene (NSSE). Front row, from left: Lionel Lim Chee Sin (NSSE), Foo Meng Wei (GPL), Chua Wee Ann (OTE) and Lum Hon Peng (CSC)
Designing shallow foundation to Eurocode 7
No full textBritish Codes and Standards (BS) have been used in practice for many years and for the past few years, it is use co-existence with Eurocodes (EC) for the past few years. The whole suite of structural Eurocodes is expected to replace the current BS Codes and standards in 2010. With this replacement, practicing engineers will need to be familiar with the methodology, design philosophy and assumptions adopted in the code.
This report presents the differences in designing shallow foundations using different geotechnical codes namely BS8004, US Naval Facilities Engineering Command (NAVFAC) and EC7. The three codes are discussed and design examples will be used in making comparison between the codes.Bachelor of Engineering (Civil
Yi ge zai Jianada wei qi si xing qi de Ying yu ke cheng de yu wen ji wen hua xue xi
No full textChan, Sin Yu.Thesis M.Phil. Chinese University of Hong Kong 2015.Includes bibliographical references (leaves 260-268).Abstracts also in Chinese; some appendixes in Chinese.Title from PDF title page (viewed on 11, November, 2016).Chan, Sin Yu
The genetic diversity and geographical separation study of Oncomelania hupensis populations in mainland China using microsatellite loci
No full text© 2016 Guan et al. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0
International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and
reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to
the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver
(http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. The attached file is the published version of the article.NHM Repositor
Stock-for-stock mergers : earnings management and the pooling-purchase choice. Do investors care?
No full textWe investigate whether there is a relationship between the level of aggression of an acquiring firm in managing earnings prior to the completion of a stock-for-stock merger and its choice of accounting method for the merger. Market reaction to the combination of earnings management and accounting method choice is also investigated
Tou guo jue dui bian yuan neng zhi ji suan, na mi ji er wei ban dao ti: er liu hua mu zhi xing tai xue yan jiu
No full textEquilibrium shape is the prerequisite to fully understanding the growth dynamics of quasi-2D structures, like transition metal dichalcogenides (TMDs). However, the intrinsic complexity of the quasi-2D nature and the complex growth environment on the edge reconstruction make it challenging to formulate a successful algorithm along with proper thermodynamic analysis. Density functional theory (DFT) emerged as a quantum mechanical tool to simulate and analyze the zero temperature physics in the world of condensed matter in the past thirty years. Physicists tried to find out the fundamental physical knowledge of TMD materials by this kind of tool. Yet, a thorough understanding of the TMD growth environment is still missing and improper physical treatments have been given to the quantum mechanical simulations. As a result, past theoretical investigations on the growth thermodynamics and kinetics of MoS₂ failed to explain all the relevant equilibrium shapes in the contemporary synthesis by atmospheric pressure chemical vapor deposition (APCVD), changing from a triangle to a hexagon then back to a triangle when the condition is changed from the Mo-rich to the S-rich limit. This reveals that there should be a missing piece of jigsaw puzzle in the understanding of edge thermodynamics. To answer this question, we proposed a modified calculation scheme with the help of electron counting model (ECM), considering edge reconstructions with S and O, and taking temperature effects into account so as to unveil the mystery of morphological changes of MoS₂ under different experimental conditions.The methodology proposed in this paper reaches a high accuracy in the estimation of the edge formation energy when compared with the past theoretical models. In addition, our model transforms the original problem, i.e. finding the edge formation energy, into first finding the pseudo chemical potentials (PCPs) of the passivating agents. This adds extra flexibility in the calculation for different edges so that arbitrary configurations can be created and calculated without involving much additional effort. Our algorithm successfully reproduces the triangle-hexagon-triangle morphological trend qualitatively, which was observed in the APCVD experiment. The great impact of our model is not only to the calculation involving MoS₂, but it is also applicable to those calculations for the other members of TMDs and is irrespective of whether the material is a semiconductor or an insulator. Besides, our approach is not limited to the low-indexed plane calculation for the edge formation energy. Therefore, it provides important insight for the edge study of more complex quasi-2D materials, e.g. Bismuth Chalcogenides which is a group of topological insulators greatly gaining interests for the technologies of spintronic devices. Hence, our results are capable of contributing to a large field of quasi-2D materials which are potential candidates to the future scientific technologies.平衡形狀是了解準二維結構材料動態生長過程的其中一個關鍵，如過渡金屬硫族化合物。由於準二維結構的先天複雜性和生長過程所處的複雜環境，使構想一個恰當的熱分析變得具挑戰性。近三十年來，密度泛函理論以量子力學研究工具的角色興起於各種凝聚物的零度物理研究。物理學家也曾以這工具對過渡金屬硫族化合物作出不同研究。然而，他們仍不能得到對這材料生長過程的全面了解，以至在模擬實驗時作出不恰當的物理設定。所以，過去的理論研究仍然不能對二硫化鉬的熱動態生長過程中所觀察到的平衡形狀作出一個準確的解釋。特別是以大氣壓化學氣相沉積的方法去合成時，便更難解釋由富鉬到富硫的生長環境時所觀察到的三角形{ 六角形{ 三角形平衡形狀趨勢。這顯示我們對於這現象的理解還有所欠缺。為了解答這難題，我們提出一個改良方案，配合電子計算模型、硫和氧的邊緣重組、溫度效應，以揭示不同形狀的二硫化鉬的背後物理成因。相對於以往的理論計算模型，我們提出的方案能得出更高的邊緣能計算準確度。除此之外，我們的模型把原本的問題由計算邊緣能轉換為先計算鈍化時牽涉的贗化學勢。我們這方法具有高度的邊緣能計算彈性，以致在計算任意的邊緣形狀時，也不需要增加過多計算資源。我們能夠成功把在大氣壓化學氣相沉積時所觀察到的三角形{ 六角形{ 三角形平衡形狀趨勢本質性地重現。這計算結果所帶來的重要影響不單是對於二硫化鉬本身，還可以應用在其他過渡金屬硫族化合物的家族成員，而且這方法與材料本身是否半導體無關。推而廣之，我們的方案不局限於低指數面的邊緣能計算，對較複雜的高指數面計算也有幫忙。因此，這為其他更複雜的準二維結構材料研究提供了重要的基礎。如碲硫族化合物，它是近年來在自旋電子學方面，科學家抱有期待的拓樸半導體材料。基於能提供種種二維和準二維材料的研究基礎，相信我們的研究成果能對未來的科技發展，特別是材料應用方面，作出重要貢獻。Sin, Chuen Keung = 透過絕對邊緣能之計算，納米級二維半導體 : 二硫化鉬之形態學研究 / 冼傳強.Mos2, 2 in title is subscriptM.Phil. Chinese University of Hong Kong 2020.Includes bibliographical references (leaves 46-50).Abstracts also in Chinese.Title from PDF title page (viewed on October 14, 2022).Sin, Chuen Keung = Tou guo jue dui bian yuan neng zhi ji suan, na mi ji er wei ban dao ti : er liu hua mu zhi xing tai xue yan jiu / Xian Chuanqiang
Indo-European vocabulary in Old Chinese : a new thesis on the emergence of Chinese language and civilization in the late Neolithic age
No full textThis study is a much expanded version of the paper I read at the XXXII International Congress for Asian and North African Studies on August 28, 1986 in Hamburg (Germany). Contents 1. Recent developments in the field of historical linguistics 2. Monosyllabic structure of Chinese words and Indo-European stems 3. Tonal accents of Middle Chinese 4. Preliminaries on the comparison of consonants and vowels 5. Some IE stems corresponding to Chinese words of entering tone 6. Middle Chinese tones and final consonants of IE stems 7. Some IE stems corresponding to Chinese words of rising tone 8. Some IE stems corresponding to Chinese words of vanishing tone 9. Some IE stems corresponding to Chinese words of level tone 10. Reconstruction of Middle Chinese vocalism according to Yün-ching 11. Old Chinese vocalism 12. Vocalic correspondences between Chinese and IE 13. Initials of Old Chinese 14. Initial consonant clusters in Old Chinese as seen from IE-stems 15. Proximity of Chinese to Germanic 16. Relation of Old Chinese to neighboring languages 17. Emergence of Chinese Empire and language in the middle of the third millennium B.C. Appendix * Abbrevations * Bibliography * Rhyme Tables of Early Middle Chinese (600) * Rhyme Tables of Early Mandarin (1300) * Word Index o English o Pinyin In 1786, just over two hundred years ago, comparative historical linguistics was born, when Sir William Jones (1746-1794) discovered the relationship between Old-Indian Sanskrit, Greek, and Latin. Since then, the emerging Indo-European philology has thrown much light on the early history of mankind in Eurasia. During the past two hundred years, many suggestions were also made in regard to relationships of Indo-European to other languages such as Semitic, Altaic, Austronesian, Korean etc., but Indo-Europeanists commonly rejected such attempts for want of convincing evidence. As to Chinese, Joseph Edkins was the first to advance the thesis of its proximity to Indo-European. In his work China's Place in Philology. An Attempt to show that the Language of Europe and Asia have a Common Origin (1871) he presented a number of Chinese words similar to those of Indo-European. In his time, Edkins' thesis seemed bold and extravagant. But today, more than a hundred years later, we are in a much better position to carry out a comprehensive and well-founded comparative study. Since the end of the nineteenth century, many Sinologists have been engaged in reconstruction of the mediaeval and archaic readings of Chinese characters. Among them, Karlgren (1889-1978) was the most successful, and in 1940 he published a comprehensive phonological and etymological dictionary entitled Grammata Serica. In the meantime, the Indo-Europeanists Alois Walde (1869-1924) and Julius Pokorny (1887-1970) were devoting themselves to the compilation of a useful etymological dictionary. The result was the Indogermanisches Etymologisches Wörterbuch by Pokorny (1959) which provides a solid basis for our lexical comparisons. Soon thereafter, some Sinologists made use of the two dictionaries by Karlgren and Pokorny to compare Chinese and Indo-European words. In 1967, an unaffiliated German scholar, Jan Ulenbrook, published an article "Einige Übereinstirnrnungen zwischen dem Chinesischen und dem Indogermanischen", in which he claimed that 57 words are related. Shortly afterwards, Tor Ulving of the University of Goteborg, Sweden, wrote a review of this article framing the title as a question: "Indo-European elements in Chinese?" While working on his thesis on word families in Chinese, Ulving compiled for his own use two dictionaries: "Archaic Chinese - English" and "English - Archaic Chinese", and discovered thereby 238 Chinese words similar to Indo-European roots. In spite of this considerable number of word equivalents, however, Mr. Ulving became discouraged and, as he told me in his letter of April, 1986, has given up his researches in this field. The skepticism, common among Indo-Europeanists in regard to comparative studies with other languages, is largely based on the dogmatic opinion that only morphology is relevant but not vocabulary. Since the typology of Chinese seems to preclude a cognate relation to Indo-European, they are inclined to discard any lexical correspondences as merely accidental or onomatopoetic. Besides, prehistorical contacts and mixtures between these languages seem not conceivable, as the Indo-Europeans are supposed to have originated in Northern Europe or at best in the Central Asian steppe, thousands of miles away from East Asia. Hence, any research into a relationship between Old Chinese and Indo-European languages would be but futile from the outset. Yet there are also opposing views among Indo-Europeanists. Investigations into Germanic languages and the oldest Indo-European language, Hittite, led some of them to a critical revision of the prevailing conception about a Proto-Indo-European. Hermann Hirt (1934) for instance states: "Inflexion of Indo-European languages is due to a relatively late development, and its correct comprehension can be achieved only by proceeding from the time of non-inflexion." And Carl Karstien (1936) holds the opinion that "Chinese corresponds most ideally to the hypothetic prototype of Indo-European." Regarding vocabulary, there are striking similarities in the monosyllabic structure of the basic words. In modern German and English, all the words of everyday speech are monosyllabic and their stereotypical structure is: initial consonant(s) + vowel(s) + final consonant(s). The same word structure is valid for Chinese as well. It is fundamentally different from the disyllabic structure of Altaic words and from the triconsonantal-disyllabic structure of Semitic words. Characteristic of the monosyllabic word structure is, besides, the complexity of the syllable nucleus, which consists of different vowels and vowel clusters in contrast to the monophthongal vocalism of polysyllabic words. Another objection raised to comparisons between Chinese and Indo-European is the existence of tonal accents in Chinese. Since most modern Indo-European languages have only expiratory accents, Chinese is considered to be a highly exotic language. Yet, even in Chinese, the use of tonal accents as a means of lexical differentiation is a result of comparatively recent development in the long history of Chinese language, the earliest monuments of which date back to 1300 B.C. (cf. Chang 1970, p.21). Unknown to Old Chinese, the existence of tonal accents was for the first time mentioned in the 5th century by Shen Yüeh (441-513). In Middle Chinese (Mch.) there were four tone categories: A P'ing-sheng 平 a level tone (which developed into Mandarin tone 1 or 2). B Shang-sheng 上 a rising tone (Mandarin tone 3). C Ch'u-sheng 去 a vanishing, i.e. falling tone (Mandarin tone 4). D Ju-sheng 入 an entering tone with a staccato effect, the word being abruptly stopped by a final consonant -p, -t, -k. (In Early Mandarin the words of this tone lost their final consonant and were distributed among the tones 2, 3 and 4, respectively according to the phonation of initials). In Middle Chinese, words of the entering tone were the only group which still preserved the final stops and therefore a close syllabic structure. So they are most appropriate for convincing comparisons with monosyllabic Indo-European word stems. The final stops -p, -t, -k of the entering tone are nowadays still extant in daily speech of several dialects in South China as well as in Chinese borrowings in Japanese, Vietnamese and Korean. As a speaker of a Taiwan dialect of Minnan origin, I could immediately identify some Indo-European stems with corresponding Chinese words. Besides, the command of Japanese and German was also a great help for this study. In the following lists I have chosen a number of Indo-European stems which are phonetically and semantically equivalent to Chinese words. Correspondences in initial and final consonants refer to the points of articulation, thus we have equations: IE labials = Old Chinese labials, IE dentals = dentals, IE l, r = dentals (cf. p. 31); Ø, i (final and medial) IE velars = velars and laryngeals, and occasionally (the so-called "satem"-forms) IE velars = dental sibilants and affricates. Regarding the manner of articulation, there are no regular correspondences between Indo-European and Chinese consonants like Grimm's law which is valid among Indo-European dialects to a certain extent. But this is not astonishing, since in Old Chinese the alternation of initials in voicing was a conventional means of creating new words from one basic form. The rules of vocalic correpondences among Indo-European dialects are quite complex. Vowels permanently change their qualities from one language to another, and from time to time within one language also, as is well known from the history of English pronunciations. Generally, the vocalism of Old Greek is taken as the standard for Proto-Indo-European. Old Chinese vowels corresponds nearly (cf. p. 30), but the details about the reconstruction of Middle and Old Chinese vocalism will be treated later (pp. 26-30). For the moment, it is necessary to notice in advance that the stem of ablauting Germanic verbs is the form of preterite or noun, rather than that of infinitive as assumed hitherto. Therefore, in some cases I must slightly modify the basic vowel of verbal stems given in Pokorny, in order to get better basis for comparison. As Old Chinese verbs were non-flexional, they might probably have preserved the original vowel the best
Transborder Industrialization and Singapore's 'Clones' in Indonesia, China and Vietnam: A Strategy Reconsidered
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