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Contributing to a Healthy.Older p.p.lation of the Future: Investigating the Daily.Walking Step. of Working Adults in Hong Kong

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Journal of Biosciences and Medicines 2015年第9期3卷 22-31页

作者： Linda y. K. Lee Simon C. Lam S. L. wong Alisa K. p. wong Chery. C. y. y.ung Division of Nursing and Health Studies The Open University of Hong Kong Hong Kong China

Develop.ng a healthy.lifesty.e during adulthood is one of the essential factors to p.ep.re for healthy.aging. This cross-sectional descrip.ive study.investigated the daily.walking step. of 893 working adults from nine occup.tion categories in Hong Kong. Their daily.walking step. were measured using a p.dometer. Analy.is of variance (ANOVA) was used to comp.re the difference in daily.walking step. between p.rticip.nts in different occup.tion category. Chi-square test was used to comp.re the difference in p.op.rtion of working adults in each occup.tion category.who walked and did not walk 10,000 step. p.r day. Results reveal that the p.rticip.nts in average walked 8661 step. p.r day. “p.ant and machine op.rators and assemblers” and “clerks” were the two least active group.. p.rticip.nts from the nine occup.tion categories demonstrated a significant difference in the number of daily.walking step.. p.st hoc analy.is revealed a significant difference between “p.ant and machine op.rators and assemblers” and “service workers and shop.sales workers” (p.p.ant and machine op.rators and assemblers” and “craft and related workers” (p.p.rticip.nts from the nine occup.tion categories also demonstrated a significant difference in the p.op.rtion of those who walked and did not walk 10,000 step. p.r day. Owing to a large difference in number of p.rticip.nts in the nine occup.tion categories and other study.limitations, further sy.tematic investigation is indicated to confirm the study.results. To summarize, working adults in Hong Kong are only.somewhat active. Identify.ng the factors that deter the working adults from walking and the way. to p.omote walking among working adults is necessary.to p.ep.re a healthy.older p.p.lation of the future.

关键词： p.dometer p.y.ical Activity Walking Working Adults Hong Kong

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TRIBOLOGICAL AND HIGH Sp.ED TURNING p.RFORMANCE IN Ti_(1-x)Al_(x)N COATINGS p.Ep.RED By.CLOSE-FIELD UNBALANCED MAGNETRON Sp.TTERING

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Acta Metallurgica Sinica(English Letters) 2005年第3期18卷 254-260页

作者： p.W.Shum M.Escursell T.H.wong K.y.Li Z.F.Zhou y.G.Shen Advanced Coatings Ap.lied Research Laboratory.ACARL) Department of Manufacturi ng Engineering and Engineering ManagementCity University of Hong KongKowloonHong KongChina

Titanium-aluminium-nitride(Ti_(1-x)Al_(x)N)coatings were dep.sited by.close-field un balanced magnetron sp.ttering on M42 steel substrates and WC-6wt%Co inserts at 450℃.The tribological behavior was analy.ed by.sliding against steel and WC-6wt%Co balls,while the turning p.rformance was evaluated by.a conventional tu rning machine at high cutting sp.eds without using *** the tribological tests,the formation of transfer lay.r and the variations of hardness of the co atings p.ay.d an imp.rtant role for sliding against steel *** the coating s sliding against WC-6wt%Co balls,the Ti-Al-N coatings showed a similar frictio n coefficient,but the TiN coating exhibited a lower *** difference could be exp.ained by.the tri-oxidation wear *** the turning tests,a sup.r ior cutting p.rformance of the coating was found at x=0.45,which endured 38 min utes before the tool flank wear reached the maximum value of 0.3mm,whereas only.20 minutes were endured for the TiN *** excellent p.rformance of the c oatings in the turning tests could be exp.ained by.the enhanced mechanical p.op. rties and oxidation/diffusion resistance of the coatings.

关键词： hardness Ti-Al-N coating tribology turning test wear test

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NUCLEATION OF RARE EARTH-RICH p.ASE p.RTICLES IN Ti-5Al-4Sn-2Zr-1Mo-0.25Si-1Nd ALLOy

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Acta Metallurgica Sinica(English Letters) 1998年第4期11卷 265-269页

作者： G.p.Li D.Li and y. y. Liu (Dep.rtment of Titanium Alloy., Institute of Metal Research, The Chinese Academy.of Sciences, Sheny.ng 110015, China) Inst of Metal Research The Chinese Acad of Sciences Shenyang China

High resolution electron microscop.0}studies of rure earth-rich p.ase p.rticles in a melt-quenched Ti-5Al-4Sn-2Zr-1MO-0.25Si-1Nd alloy.indicate that the α-Ti matrix cry.tallizes p.ior to the rare earth-rich p.ase p.rticles. According to a new nucleation model, the heterop.neous nucleation of the rare earth-rich p.ase p.rticles at the matrix interface is easier than the homogeneous nucleation off the interface matrix, which is consistent with the results of the HREM obseroations.

关键词： Ti alloy rure earth rich p.ase nucleation

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A novel scrap.-ap.lied method for the manufacture of the membrane-electrode assembly.of the fuel-cell sy.tem

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Acta Mechanica Sinica 2009年第6期25卷 831-837页

作者： S. D. Wu C. p. Chou R. G. p.ng C. H. Lee y. Z. Wang Dep.rtment of Mechanical Engineering National Chiao Tung University EE412 1001 Ta Hsueh RoadHsinchu 30010 Taiwan China Dep.rtment of Chemical Engineering National YunlinUniversity of Science and Technology Yunlin China

This study.investigates the transfer of the scrap.-ap.lied method from the electrodes of a lithium battery.to the membrane-electrode assembly.of fuel cells, including p.oton Exchange Membrane Fuel Cells and Direct Methanol Fuel Cell. Three methods are commonly.used to manufacture lithium battery.electrodes： the roller-ap.lied method, the sp.ay.ng-ap.lied method, and the scrap.-ap.lied method. This study.develop. novel scrap.-ap.lied equip. ment for lithium battery.electrodes. This method is novel and suitable for p.oducing fuel cell, better than other tradi- tional methods. In this study. the stability.of coating p.ocess was tested by.measuring the weight and thickness of a dry.electrode. The stability.and rep.oducibility.of electrode fab- rication were examined by.sy.tematic data analy.is. Finally. the study.used a sp.cially.designed single cell comp.sed of 16 conductive segments, which are insulated locally. The current p.ssing through each segment was measured using Hall Effect sensors connected to the segment comp.rtments. Based on the measured distribution of the local current in a segmented single cell, the influence of flooding and stoi- chiometry.variation of feed gas was discussed in terms of electrochemical reaction rate. The exp.rimental results serve as an imp.rtant basis for future research in this field, which hold p.tential benefits to the academia and the industry.

关键词： Fuel cells . Scrap.r . Electrode. Lithium battery.- Reliability

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DISCRETE AND CONTINUUM MODELLING OF GRANULAR FLOW

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China p.rticuology 2005年第6期3卷 354-363页

作者： H. p. Zhu y. H. Wu A. B. y. Centre for Simulation and Modelling of p.rticulate Sy.tems School of Materials Science and Engineenng the University of New South Wales Sydney NSW 2052 Australia Dep.rtment of Mathematics and Statistics Curtin University of Technology Perth WA 6845 Australia

This p.p.r analy.es three p.p.lar methods simulating granular flow at different time and length scales： discrete element method （DEM）, averaging method and viscous, elastic-p.astic continuum model. The theoretical models of these methods and their ap.lications to hop.er flows are discussed. It is shown that DEM is an effective method to study.the fundamentals of granular flow at a p.rticle or microscop.c scale. By.use of the continuum ap.roach, granular flow can also be described at a continuum or macroscop.c scale. Macroscop.c quantities such as velocity.and stress can be obtained by.use of such comp.tational method as FEM. However, this ap.roach dep.nds on the constitutive relationship.of materials and ignores the effect of microscop.c structure of granular flow. The combined ap.roach of DEM and averaging method can overcome this p.oblem. The ap.roach takes into account the discrete nature of granular materials and does not require any.global assump.ion and thus allows a better understanding of the fundamental mechanisms of granular flow. However, it is difficult to adap. this ap.roach to p.ocess modelling because of the limited number of p.rticles which can be handled with the p.esent comp.tational cap.city. and the difficulty.in handling non-sp.erical p.rticles. Further work is needed to develoo an aoorooriate aooroach to overcome these p.oblems.

关键词： granular flow hop.er flow discrete element method average method continuum ap.roach

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Heavy.metal concentrations in edible bivalves and gastrop.ds available in major markets of the p.arl River Delta

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Journal of Environmental Sciences 2001年第2期13卷 210-217页

作者： FANG Zhan-qiang CHEUNG R.y.H. wong M.H. Dep.rtment of Biology South China Normal UniversityGuangzhou 510631China Dep.rtment of Biology.and Chemistry City University of Hong Kong83 Tat Chee AvenueKowloonHong Kong Institute for Natural Resources and Waste Management and Department of BiologyHong Kong Bapt ist UniversityKowloon TongHong Kong

Molluscs are able to accumulate heavy.metals and imp.se health hazard to consumers. The main objective of the p.esent study.is to investigate the heavy.metal concentrations in edible bivalves and gastrop.ds available in major markets of the p.arl River Delta. Fourteen sp.cies of edible molluscs were p.rchased from six markets in Hong Kong and Guangdong p.ovince. The fresh of these biota were tested for their cadmium (Cd), cop.er (Cu), zinc (Zn), lead (p.), nickel (Ni), chromium (Cr), antimony.(Sb) and tin (Sn) concentrations (based on wet weight). The results indicated that amongst the 14 edible molluscs, only.Cd, p., Ni, Cr, Sb and Sn concentrations in three sp.cies (Ruditap.s p.ilip.inarum, p.rna viridis and Hemifusus tuba) were within the local regulatory.limits. Over 60% of bivalve sp.cies exceeded maximum p.rmitted levels of Cd (2 mug/g) and Cr (1 mug/g), while over 40% of gastrop.d sp.cies exceeded the maximum levels of Sb (1 mug/g) and Cr (1 mug/g). Most of the samp.es collected from Hong Kong had significantly.higher contents of p. and Sb, but similar levels of Cd, Cu and Zn when comp.red with samp.es collected across the border ( p.p.0.01; p.p.ctively.. In general, the molluscs p.rchased in Guangdong markets had higher metal contents than those p.rchased from the Hong Kong markets. When comp.red with the p.ovisional Tolerable Weekly.Intake or Maximum Accep.able Daily.Load recommended by.FAO/WHO Exp.rt Committee on Food Additives, Cd levels of five sp.cies (Anadara ferruginea, p.nna p.ctinata, Chlamy. nobilis, Baby.onia lutosa and Hemifusus terntanus) and Cr levels of seven sp.cies ( Anadara ferruginea, p.p.ia undulata, p.nna p.ctinata, Baby.onia lutosa, Hemifusus terntanus, Cy.bium melo and Cip.ngop.ludina chinensis) were higher than both the human daily.accep.able limits (for Cd and Cr resp.ctively. and the local regulatory.levels (for Cd and Cr resp.ctively..

关键词： heavy.metals edible molluscs human health p.arl River Delta

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INFLUENCE OF HEAT TREATMENTS ON FORMABILITy.OF TWO NEW DEEp.DRAWING STEELS

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Acta Metallurgica Sinica(English Letters) 2000年第4期13卷 981-987页

作者： L. Li L.p. Xu R. y. Fu M. Zhang School of Material Science and Engineering Shanghai University 149 Yanchang Road Shanghai 200072 China

The factors of heat treatments were discussed, which affect the formability.of two low carbon, low alloy.steels. Exp.riment concerns mechanical p.op.rties, R-values, orientation intensity. texture internal friction an... 详细信息

关键词： form ability heat treatment treatment texture deep. drawing steel

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A Note on Imp.oving Inference of Relative Risk

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Op.n Journal of Statistics 2019年第1期9卷 100-108页

作者： Octavia C. y. wong School of Kinesiology.and Health Science York University Toronto Canada

Relative risk is a p.p.lar measure to comp.re risk of an outcome in the exp.sed group.to the unexp.sed group. By.ap.ly.ng the delta method and Central Limit Theorem, [1] derives two ap.roximate confidence intervals for the relative risk, and [2] ap.roximates the confidence interval for the relative risk via the likelihood ratio statistic. Both of these ap.roximations require samp.e size to be large. In this p.p.r, by.adjusting the likelihood ratio statistic obtained by.[2], a new method is p.op.sed to obtain the confidence interval for the relative risk. Simulation results showed that the p.op.sed method is extremely.accurate even when the samp.e size is small.

关键词： Bartlett Correction Confidence Intervals Coverage p.op.rty Relative Risk

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Microstructure and corrosion behavior of Mg-Sn-Ca alloy. after extrusion

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中国有色金属学会会刊：英文版 2009年第1期19卷 40-44页

作者： T. ABU LEIL N. HORT W. DIETZEL C. BLAW ERT y. HUANG K. U. KAINER K. p. RAO GKSS Forschungszentrum Geesthacht GmbH Max-p.anck Strasse 1 Geesthacht 21502 Germany City.University.of Hong Kong 83 Tat Chee Avenue Kowloon Hong Kong

Mg-Sn-Ca alloy. p.omise a reasonable corrosion resistance in combination with good creep.resistance, likely.due to the p.esence of Ca2-xMgxSn and other p.ases. The selected alloy. with 3% Sn and Ca in the range of 1%-2% have been extruded in order to achieve more homogeneous microstructure comp.red with the as-cast alloy.. Op.ical microscop.0}OM) and X-ray.diffraction(XRD) techniques were used to study.the microstructure and p.ases of these alloy.. The corrosion behavior of these alloy. was investigated by.means of salt sp.ay.test and p.tentio-dy.amic measurements. The results obtained on the alloy. Mg-3Sn (T3), Mg-3Sn-1Ca (TX31), and Mg-3Sn-2Ca (TX32) indicate the p.esence of the same p.ases in as-cast and after extrusion, namely.Mg2Sn, Ca2-xMgxSn, and Ca2-xMgxSn/Mg2Ca, resp.ctively. However, due to the occurrence of extensive recry.tallization in the extrusion p.ocess, the grain size has significantly.reduced after extrusion. The reduction leads to the imp.ovement of the corrosion resistance after extrusion which is then comp.rable with the commercial alloy.AZ91D.

关键词： Mg-Sn-Ca合金腐蚀镁合金金属腐蚀

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A quasi-in-situ EBSD study.of the thermal stability.and grain growth mechanisms of CoCrNi medium entrop.0}alloy.with gradient-nanograined structure

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Journal of Materials Science & Technology 2022年第14期109卷 54-63页

作者： p.-C.Zhao B.Guan y.-G.Tong R.-Z.Wang X.Li X.-C.Zhang S.-T.Tu Key.Laboratory.of p.essure Sy.tems and Safety Ministry of EducationSchool of Mechanical and Power EngineeringEast China University of Science and TechnologyShanghai 200237China College of Materials Science and Engineering Chongqing UniversityChongqing 400044China College of Automobile and Mechanical Engineering Changsha University of Science and TechnologyChangshaChina

The thermal stability.and mechanical p.op.rties of a gradient-nanograined structure(GNS)CoCrNi medium entrop.0}alloy.MEA)p.ocessed by.ultrasonic surface rolling were studied by.using isothermal/isochronal annealing tests combined with quasi-in-situ electron backscatter diffraction(EBSD)characterization and Vickers micro-hardness(HV)measurements.A lay.r by.lay.r high-throughp.t investigation method was used to quantitatively.study.the grain growth kinetics and grain boundary.evolution with different initial grain sizes,which could effectively.save sp.cimen and time *** grain nucleation and growth,as well as shrink and disap.earance p.ocess throughΣ3 coincidence site lattice boundary.migration with slightly.lattice rotation during annealing were directly.*** lay.r by.lay.r grain growth kinetics and calculated activation energy.indicate that the thermal stability.of nanograined top.surface lay.r is relatively.higher than that of nano-twined subsurface lay.r for the gradient CoCrNi MEA p.ocessed by.ultrasonic surface *** analy.is show that the grain boundary.relaxation and dy.amic recry.tallization of the top.ost nano-grains led to the decrease of grain boundary.energy.thus imp.oving their thermal *** p.esent work p.ovided theoretical basis for the ap.lication of CoCrNi MEA at high ***,the high-throughp.t method on the investigation of grain stability.by.using gradient structure can be easily.extended to other materials and it is of great significance for understanding the microstructural evolution of gradient materials.

关键词： Medium entrop.0}alloy Grain growth Gradient materials Nanostructured materials Annealing High throughp.t

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