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Tailoring specific properties of polymer-based composites by using graphene and its associated compounds

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International Journal of Smart and Nano Materials 2020年第2期11卷 173-189页

作者： Pui-yan Hung kin tak lau Qiaoshi Guo Baohua Jia Bronwyn Fox Faculty of Science Engineering and TechnologySwinburne University of TechnologyMelbourneVICAustralia SEMITRI Pty Ltd Watsonia NorthMelbourneVICAustralia

Graphene and its associated compounds have been identified as extraordinary structural nano-fillers that can tailor the properties of new polymer-based composites with specific *** possesses perfect 2D atomic architecture and has a large surface area that enhances the bonding,with tailored functional groups on its surface with polymer chains to form high strength ***,a lot of research has focused on developing composites with high specific strength,high electrical and thermal conductivities,high impact resistance,excellent energy storage capability and ability to maintain their strength at low-temperature environments by using graphene,graphene oxide(GO),reduced graphene oxide(rGO)or carbon nanotube/*** goals are to design composites that can meet specific requirements for different engineering *** this paper,the discussion on all aspects in relation to the use of graphene and its associated compounds for advanced composites will be given in *** potentiality of using these materials for high-tech applications will be *** to date,it has been proved that the use of graphene-based nanofillers does improve the mechanical,interfacial bonding,electrical,thermal and electromagnetic interference shield properties of polymer-based *** adding a small amount of these nanofillers do make a big difference to the properties of host materials.

关键词： Graphene mechanical Properties energy low Temperature

Biocomposites:Their multifunctionality

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International Journal of Smart and Nano Materials 2010年第1期1卷 13-27页

作者： kin-tak lau Mei-po Ho Chi-ting Au-Yeung Hoi-yan Cheung Centre of Excellence in Engineered Fibre Composites Faculty of Engineering and SurveyingUniversity of Southern QueenslandQueenslandAustralia Department of Mechanical Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina

During the last decade,tissue engineering has shown a considerable promise in providing more viable alternatives to surgical procedures for harvested tissues,implants and *** to the fast development on nano-and biomaterial technologies,it is now possible for doctors to use patients’cells to repair orthopaedic defects such as focal articular cartilage *** order to support the three-dimensional tissue formation,scaffolds made by biocompatible and bioresorbable polymers and composite materials,for providing temporary support of damaged body and cell structures,have been developed *** ceramic and metallic materials have been widely accepted for the development of implants,their non-resorbability and necessity of second surgical operation(like for bone repair),which induce extra pain for the patients,limit their wide *** development of different types of biocomposites for biomedical engineering applications is *** biocomposites include(i)basic biomaterials;(ii)natural fiber-reinforced biocomposites and(iii)nanoparticle-reinforced *** multifunctionality is discussed in terms of the control of mechanical properties,biodegradability and bioresorbability.

关键词： multifunctional materials biocomposite

Measurements of Heat Treatment Effects on Bovine Cortical Bones by Nanoindentation and Compression Testing

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Journal of Biomaterials and Nanobiotechnology 2012年第1期3卷 105-113页

作者： Mei-ling lau kin-tak lau Harry Ku Debes Bahattacharyya Yan-dong Yao Centre for Advanced Composite Materials Department of Mechanical Engineering The University of Auckland Auckland New Zealand Centre of Excellence in Engineered Fibre Composites Faculty of Engineering and Surveying University of Southern Queensland Toowoomba Australia Department of Applied Biology and Chemical Technology The Hong Kong Polytechnic University Hong Kong China

Heat treatment of bone is one of the reliable and simple sterilization methods to overcome the risk of rejection and disease transfer from allograft and xenograft, in particular for the prevention of human immunodeficiency virus (HIV) infection. However, the mechanical property of the micro-structural level after heat treatment is not well characterized. To address this issue, this study was carried out to compare the localized mechanical properties of micro-structural tissue with those at the global structural level. Nanoindentation technique has been well accepted as an accurate technique to measure mechanical property of small and heterogeneous specimen nondestructively, as well as the complex bio-material of micro-structural level, often with a resolution of better than 1 μm. In this study, nanoindentation was conducted to measure the localised elastic modulus and hardness values of bones at temperature of 23°C (room temperature – non-heated sample), 90°C and 150°C, respectively. All experiments were conducted at room temperature (~23°C). The elastic modulus (E) and nanoindentation hardenss (H) values in the longitudinal direction of bones heated at 150°C were recorded as 23.43 GPa and 0.73 GPa, respectively;as in transverse direction, the E and H values were 12.77 GPa and 0.54 GPa, respectively. It showed significant increases of 44% and 43% in the longitudinal direction as compared to those of the non heat-treated bones. In addition, E and H values in transverse direction also showed increases of 23% and 38%, respectively as compared to those of the non heat-treated bones. Furthermore, heat-treated bones at 90°C in longitudinal direction also appeared to have significant increases of 18% and 31% in E and H values, respectively. However, the E and H values in transverse direction increase only by 0.4% and 12.8%, respectively. In addition, compressive test is employed to measure the global stiffness (E) of the bone samples. When heated at 150°C, the bone specime

关键词： Bone Heat Treatment Nanoindentation Mechanical Properties BSE and EDX

Resistance of Nanoclay Reinforced Epoxy Composites to Hyperthermal Atomic Oxygen Attack

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Chinese Journal of Chemical Physics 2019年第5期32卷 543-552页

作者： Hei-long Wang Vanessa J. Murray Min Qian Donna J. Minton Ai-yi Dong kin-tak lau Bo-han Wu Li Che Timothy K. Minton College of Science Dalian Maritime University Dalian 116026 China State Key Laboratory of Molecular Reaction Dynamics Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 China Department of Chemistry and Biochemistry Montana State University 103 Chemistry and Biochem- istry Bldg. Bozeman Montana 59717 United States of America Department of Physics School of Science East China University of Science and Technology Shanghai 200237 China Faculty of Science Engineering and Technology Swinburne University of Technology Hawthorn VIC 3122 Australia Beijing Institute of Spacecraft Environment Engineering Beijing 100094 China

Due to outstanding mechanical properties, heat resistance, and relatively facile production,nanoclay reinforced epoxy composites(NCRE composites) have been suggested as candidate materials for use on external surfaces of spacecraft residing in the low Earth orbit(LEO) environment. The resistance of the NCRE composites to bombardment by atomic oxygen(AO), a dominant component of the LEO environment, has been investigated. Four types of samples were used in this study. They were pure epoxy(0 wt% nanoclay content), and NCRE composites with different loadings of nanoclay—1 wt%, 2 wt%, and 4 wt%. Etch depths decreased with increasing nanoclay content, and for the 4 wt% samples it ranged from 28% to 37% compared to that of pure epoxy. X-ray photoelectron spectroscopy(XPS) indicates that after AO bombardment, relative area of C-C/C-H peak decreased,while the area of the C-O, ketones peaks increased, and the oxidation degree of surfaces increased. New carbon-related component carbonates were detected on nanoclay containing composite surfaces. Scanning electron microscopy indicates that aggregates formed on nanoclay-containing surfaces after AO bombardment. The sizes and densities of aggregates increased with nanoclay content. The combined erosion depths, XPS and SEM results indicate that although all the studied surfaces got eroded and oxidized after AO bombardment,the nanoclay containing composites showed better AO resistance compared to pure epoxy,because the produced aggregates on surface potentially act as a physical "shield", effectively retarding parts of the surface from further AO etching.

关键词： Atomic oxygen Epoxy Nanoclay Low Earth orbit

溶剂对碳纳米管/环氧树脂复合材料力热性能的影响

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机械设计与研究 2005年第4期21卷 81-84,87页

作者：刘建德陆梅梁天培香港理工大学机械工程系

制备了碳纳米管/环氧树脂复合材料,分析了分散碳纳米管的溶剂对复合材料热学,力学行为的影响。溶剂效应由大到小依次为DMF,乙醇和丙酮,与三种溶剂的沸点顺序一致。溶剂效应被认为是未挥发完全的残留溶剂对环氧树脂固化反应的影响,从而... 详细信息

制备了碳纳米管/环氧树脂复合材料,分析了分散碳纳米管的溶剂对复合材料热学,力学行为的影响。溶剂效应由大到小依次为DMF,乙醇和丙酮,与三种溶剂的沸点顺序一致。溶剂效应被认为是未挥发完全的残留溶剂对环氧树脂固化反应的影响,从而导致了固化机理的不同。FTIR通过对比不同溶剂分散的复合材料的分子结构,证明了溶剂效应与复合材料中未反应完的环氧树脂及固化反应的完全程度有关,因而导致了不同的热、力学行为。

关键词：碳纳米管聚合物复合材料力学性能

碳纤维复合材料芯导线芯棒压接不同心问题研究

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复合材料科学与工程 2022年第1期 79-85页

作者：宋泽明万建成朱波刘建德罗宏建中国电力科学研究院有限公司北京100055 山东大学济南250100 斯威本科技大学维多利亚3122 国网浙江省电力有限公司电力科学研究院杭州310014

在以往的碳纤维复合材料芯导线(下文简称"碳纤维导线")架设工程建设阶段的X射线检测工作中,除碳纤维复合材料芯棒(下文简称"芯棒")常规的显性缺陷外还发现了一种其与楔形夹座不同心的现象,而此类缺陷未经过研究,长远影响尚未可知。本文... 详细信息

在以往的碳纤维复合材料芯导线(下文简称"碳纤维导线")架设工程建设阶段的X射线检测工作中,除碳纤维复合材料芯棒(下文简称"芯棒")常规的显性缺陷外还发现了一种其与楔形夹座不同心的现象,而此类缺陷未经过研究,长远影响尚未可知。本文基于碳纤维芯导线压接X射线的检测图像,对压接不同心现象进行了分析,给出了芯棒压接不同心的定义,并提出了造成芯棒压接后不同心的原因;根据导线、金具、芯棒参数,提炼出芯棒压接不同心的数值仿真模型,并建立起芯棒压接不同心所产生弯曲变形效应的有限元计算模型;然后,通过对芯棒压接不同心的弯曲变形力学问题的静力学仿真计算,分析了其在压接不同心环境中的静力学响应,评估了压接不同心造成的安全隐患,为碳纤维导线压接工艺的改善提供理论支撑。

关键词：碳纤维复合芯导线压接 X射线检测同心度仿真计算

New tricyanoiron(Ⅲ) building blocks for the construction of molecule-based magnets

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Science China Chemistry 2010年第10期53卷 2106-2111页

作者： lau Pui-Ha WONG Wing-tak lau Tai-Chu Department of Biology and Chemistry City University of Hong Kong Department of Chemistry The University of Hong Kong

A series of tricyanoiron(Ⅲ) complexes with the general formula mer-[FeⅢ(5-Xsap)(CN)3]2-(X = H, Me, MeO, Cl or Br, sapH2 = N-salicylidene-o-aminophenol) have been synthesized. These complexes were characterized by IR, ESI-MS, UV/Vis, elemental analysis and magnetic measurements. The structures of (PPh4)2[FeⅢ(sap)(CN)3] and (PPh4)2[FeⅢ(5-Mesap)(CN)3] have been determined by X-ray crystallography. These low-spin d5 tricyanoiron(Ⅲ) complexes are potential building blocks for the construction of molecule-based magnets.

关键词： cyano iron Schiff base building block molecule-based magnet

Outcome of 1355 consecutive transabdominal chorionic villus samplings in 1351 patients

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中华医学杂志(英文版) 2005年第20期000卷 5-11页

作者： lau Tze kin,LEUNG tak Yeung,FUNG tak Yuen,Daljit S SAHOTA,LEUNG Tse Ngong Fetal Medicine Unit Department of Obstetrics and Gynaecology Prince of Wales Ho spital Chinese University of Hong Kong Shatin Hong Kong SAR China Fetal Medicine Unit Department of Obstetrics and Gynaecology Prince of Wales Ho spital Chinese University of Hong Kong Shatin Hong Kong SAR China Fetal Medicine Unit Department of Obstetrics and Gynaecology Prince of Wales Ho spital Chinese University of Hong Kong Shatin Hong Kong SAR China Fetal Medicine Unit Department of Obstetrics and Gynaecology Prince of Wales Ho spital Chinese University of Hong Kong Shatin Hong Kong SAR China Fetal Medicine Unit Department of Obstetrics and Gynaecology Prince of Wales Ho spital Chinese University of Hong Kong Shatin Hong Kong SAR China

Background The true risk of choronic villus sampling (C VS) is poorly defined. The objective of this study was to review the clinical o utcome of transabdominal CVS performed in a university teaching unit, with an em phasis on the complication rate. Methods A comprehensive audit database was maintained for 1351 pregnant women, including 17 sets of twin pregnancies, who had a CVS. Details a nd outcome of all CVSs made in the unit between May 1996 and May 2004 were revie wed. All CVSs were performed by one of 5 operators using the identical techniqu es. Results All procedures were performed transabdominally. A tota l of 1355 CVSs were performed because there were 4 dichorionic twin pregnancies which required 2 punctures. The mean gestation at CVS was (11.8±0.7) weeks, and 97.3% of the procedures were performed between 11 and 13 completed weeks. The majority (96.2%) required only 1 puncture to achieve correct needle placeme nt. The procedure failed to obtain an adequate sample in 4 subjects (0.30%). A total of 1351 chromosomal studies were requested and there was 1 case (0.07%) of culture failure. The results of chromosomal studies were available within 1 4 days in 36.7% of the cases and within 21 days in 94.0%. Overall, 77 chromos omal abnormalities (5.7%) and 5 cases of thalassemia major were detected. Preg nancy outcome was unknown in only 13 singleton subjects (0.96%). In the remain ing 1355 fetuses, there were 76 pregnancy terminations (5.56%), 10 fetal losses with obvious obstetric causes (0.73%), and 21 potentially procedure-relat ed fetal losses (1.54%). In the last group, the majority had one or more co-e xisting obstetric complications. The background fetal loss rate for pregnancies at similar gestational age in the unit was about 0.8%. Therefore, the procedu re-related fetal loss rate was estimated to be at the maximum of 0.74%. Conclusions In experienced hands, first trimester transabdomina l CVS is an accurate and safe invasive prenatal diagnostic procedur

关键词： chorionic villus sampling · postoperative complication · pregnancy outcome

Spreadsheet quality assurance:a literature review

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Frontiers of Computer Science 2024年第2期18卷 61-82页

作者： Pak-Lok POON Man Fai lau Yuen tak YU Sau-Fun TANG School of Engineering and Technology Central Queensland UniversityMelbourne 3000Australia Department of Computing Technologies Swinburne University of TechnologyHawthorn 3122Australia Department of Computer Science City University of Hong KongHong Kong SAR 999077China The Royal Victorian Eye and Ear Hospital East Melbourne 3002Australia

Spreadsheets are very common for information processing to support decision making by both professional developers and non-technical end ***,business intelligence and artificial intelligence are increasingly popular in the industry nowadays,where spreadsheets have been used as,or integrated into,intelligent or expert systems in various application ***,it has been repeatedly reported that faults often exist in operational spreadsheets,which could severely compromise the quality of conclusions and decisions based on the *** a view to systematically examining this problem via survey of existing work,we have conducted a comprehensive literature review on the quality issues and related techniques of spreadsheets over a 35.5-year period(from January 1987 to June 2022)for target journals and a 10.5-year period(from January 2012 to June 2022)for target *** other findings,two major ones are:(a)Spreadsheet quality is best addressed throughout the whole spreadsheet life cycle,rather than just focusing on a few specific stages of the life cycle.(b)Relatively more studies focus on spreadsheet testing and debugging(related to fault detection and removal)when compared with spreadsheet specification,modeling,and design(related to development).As prevention is better than cure,more research should be performed on the early stages of the spreadsheet life *** by our comprehensive review,we have identified the major research gaps as well as highlighted key research directions for future work in the area.

关键词： decision support system end-user computing end-user programming Excel spreadsheet