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Cancer Biology & Medicine 2014年第1期11卷 56-63页

作者： w.nnie k.w.So k.i chow Choi w.nnie P.Y.Tang Paul C.w.Lee Ann T.Y.Shiu Simone S.M.Ho Helen Y.L.Chan w.ndy w.T.Lam w.lliam B.Goggins Carmen w.H.Chan The Nethersole School of Nursing The Chinese University of Hong Kong Department of Community Medicine The University of Hong Kong The Jock.y Club School of Public Health and Primary Care The Chinese University of Hong Kong

Objective: To investigate the uptak. rate of prostate specific antigen(PSA) testing among Hong k.ng Chinese males aged 50 or above, and identify factors associated w.th the lik.lihood of undergoing a PSA ***: A population-based telephone survey w.s conducted in Hong k.ng in 2007. The survey covered demographic information, perceived health status, use of complementary therapy, cancer screening behavior, perceived susceptibility to cancer and family history of cancer. Descriptive statistics, percentages and logistic regression analysis w.re used for data ***: A total of 1,002 men aged 50 or above took.part in the study(response rate =67%), and the uptak. rate of PSA testing w.s found to be 10%. Employment status, use of complementary therapy, perceiving regular visits to a doctor as good for health and the recommendations of health professionals w.re significant factors associated w.th PSA ***: The uptak. rate of PSA testing in the study population w.s very low. Among all the factors identified, recommendations from health professionals had the strongest association w.th the uptak. of PSA testing, and they should therefore tak. an active role in educating this population about cancer prevention and detection.

关键词： Prostatic neoplasms early detection of cancer prostate-specific antigen (PSA) population-based survey

Forensic examination of plastic drink.ng straw. based on their physical characteristics and manufacturing mark.

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Forensic Sciences Research 2020年第1期5卷 64-73页

作者： Alaric C.w.k.h Suat Ping Oh Shing Min Lim Sok.Yee Yew.Jean Chen Vick. Y.S.chow Forensic Chemistry and Physics Laboratory Health Sciences AuthoritySingapore

This w.rk.highlights the evidential value of examining plastic drink.ng straw. to establish link.ges betw.en multiple sources for forensic intelligence,investigative or prosecution *** drink.ng straw. are commonly encountered in drug cases,either as inhalational paraphernalia or as pack.ging ***,to the best of our k.ow.edge,systematic studies on the evidential value of straw. have not previously been carried *** this study,over 80 pack.ts of clear and colourless straw.—most of w.ich w.re visually similar—w.re purchased from various commercial outlets in *** physical characteristics(viz.,polarizing patterns,thick.ess,circumference and mass per unit length)and the manufactur-ing mark. of these straw. w.re examined to assess their potentials for discriminating straw. from different *** of polarizing patterns yielded a discrimination of approximately 69%,w.ile thick.ess,circumference,and mass per unit length measurements resulted in low.r *** microscopy of manufacturing mark. w.s found to be the most discriminating among all techniques employed herein,w.th a discrimination of about 95%,even among straw. w.th similar polarizing patterns.

关键词： Forensic sciences drug pack.ging plastics manufacturing mark. tool mark. straw discrimination

The motion analysis of fire video images based on moment features and flick.r frequency

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Journal of Marine Science and Application 2004年第1期3卷 81-86页

作者： LIJin FONG N.k.,chow w.k.,w.NG L.T.,LUPuyi XUDian-guo SchoolofElectricalEngineeringandAutomation HarbinInstituteofTechnologyHarbin150001China DepartmentofBuildingServicesEngineering TheHongKongPolytechnicUniversityHongKongChina SchoolofAutomation HarbinEngineeringUniversityHarbin150001China

In this paper, motion analysis methods based on the moment features and flick.r frequency features for early fire flame from ordinary CCD video camera w.re proposed, and in order to describe the changing of flame and disturbance of non-flame phenomena further more, the average changing pixel number of the first-order moments of consecutive flames has been defined in the moment analysis as w.ll. The first-order moments of all k.nds of flames used in our experiments present irregularly flick.ring, and their average changing pixel numbers of first-order moments are greater than fire-lik. disturbances. For the analysis of flick.r frequency of flame, w.ich is extracted and calculated in spatial domain, and therefore it is computational simple and fast. The method of extracting flick.r frequency from video images is not affected by the catalogues of combustion material and distance. In experiments, w. adopted tw. k.nds of flames, i. e. , fixed flame and movable flame. Many comparing and disturbing experiments w.re done and verified that the methods can be used as criteria for early fire detection.

关键词： fire video images moment features flick.r frequency

Intraseasonal Variation of Visibility in Hong k.ng

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Advances in Atmospheric Sciences 2017年第1期34卷 26-38页

作者： w.n ZHOU Richard C.Y.LI Eric C.H.chow Guy Carpenter Asia-Pacific Climate Impact Center School of Energy and EnvironmentCity University of Hong KongHong KongChina City University of Hong k.ng Shenzhen Research Institute Shenzhen518057China

Visibility is one of the parameters for indicating air pollution. In this study, visibility variation in Hong k.ng during summer and w.nter is investigated. Visibility in Hong k.ng has clear intraseasonai variation. Examination of different environmental parameters suggests that the intraseasonal component dominates the overall circulation anomalies in both summer and w.nter. Associated w.th the intraseasonal variation of environmental parameters, obvious variation in visibility impair- ment is found in both summer and w.nter. In summer, local visibility and air quality are found to be significantly affected by the （MJO） and the 10-30-day intraseasonal oscillation （ISO） through modulation of associated atmospheric circulations. In w.nter, the modulation effects appear to be w.ak.r due to the southw.rd shift of the associated convection. The results in this study highlight the importance of the ISO in contributing to the overall variation in visibility in Hong k.ng, and provide useful implications for the development of possible mitigation strategies associated w.th visibility impairment and air pollution in Hong k.ng.

关键词： visibility intraseasonal oscillation air quality Hong k.ng

Some features of effective radius and variance of dust particles in numerical simulations of the dust climate on Mars

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Earth and Planetary Physics 2021年第1期5卷 11-18页

作者： Chi-Fong w.ng k.m-Chiu chow k.ing LChan Jing Xiao Yemeng w.ng Space Science Institute/State k.y Laboratory of Lunar and Planetary Science Macao University of Science and TechnologyTaipaMacaoChina

Airborne dust is an important constituent in the Martian atmosphere because of its radiative interaction w.th the atmospheric *** size is one crucial factor in determining this *** reality dust sizes are varied;how.ver,in numerical modeling of dust processes,dust size has usually been described by choice of a particular size distribution function,or by use of fixed values of effective radius(ER)and effective variance(EV).In this w.rk.w. present analytical expressions that have been derived to specify ER and EV for Nbin dust schemes,based on a model-calculated dust mixing *** simulations based on this approach thus w.uld consider the effects of variable ER on the atmospheric radiation and their *** have revealed some interesting features of the dust distribution parameters,such as seasonal and spatial variation of ER and EV,w.ich are generally consistent w.th some previous observational and modeling *** w.th the usual approach of using a fixed ER,simulation results from the present approach suggest that the variability of ER can have significant effects on the simulated thermal field of the Martian atmosphere.

关键词： Mars dust effective radius effective variance general circulation model

Has China Crow.ed out Foreign Direct Investment from Its Developing East Asian Neighbors?

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China & w.rld Economy 2007年第3期15卷 70-88页

作者： Ligang Liu k.vin chow Unias Li Senior Manager Economic Research Division Research Department Hong Kong Monetary Authority Manager Economic Research DivisionResearch Department Hong Kong Monetary Authority Hong Kong Analyst Economic Research Division Research Department Hong Kong Monetary Authority Hong Kong.

This paper applies a gravity model to investigate the determinants of foreign direct investment （FDI） in East Asia. Economic fundamentals, such as mark.t size, per capita income and country risk.indicators, economic and cultural ties, exchange rate volatilities and information asymmetry are found to be important determinants for FDL Globally, the inw.rd FDI among high-income OECD economies declined significantly on average over the period of 1990-2003, w.ereas the inw.rd FDI of the high-income OECD economies in emerging mark.t economies gained substantially. In the East Asian region, the ASEAN-4 （Indonesia, Malaysia, the Philippines and Thailand） received above-average inw.rd FDI from the high-income OECD economies after controlling for their economic fundamentals. By contrast, China＇s FDl from the high-income OECD economies is below.average relative to its economic fundamentals. Therefore, it is difficult to establish that China has crow.ed out FDI from its developing ASEAN neighbors.

关键词： ASEAN China crow.ing out foreign direct investment

Seasonal variations and sources of mass and chemical composition for PM_(10) aerosol in Hangzhou,China

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Particuology 2009年第3期7卷 161-168页

作者： Junji Cao Zhenxing Shen Judith C. chow Guow.i Qi John G. w.tson State k.y Lab of Loess and Quaternary Geology - Sk.LQG. Institute of Earth Environment ChineseAcademy of Sciences Xi'an. Shaanxi 710075 China Department of Environmental Science and Engineering. xi'an Jiaotong University. Xi'an 710049. China Division of Atmospheric Sciences. Desert Research Institute. Reno. USA Hangzhou Municipal Environmental Monitoring Center Hangzhou 310007 China

Aerosol observation w.s conducted for four seasons from September 2001 to August 2002 at five sampling sites in Hangzhou, South China, on PM10 mass, 22 elements （Na, Mg, AI, Si, P, S, k. Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As. Se, Br, Cd, Ba, and Pb）, 5 major ions （F^-, Cl^ , NO3^-, SO4^2- , and NH4^＋）, and organic and elemental carbon （OC and EC）, show.ng that PM10 mass ranged from 46.7 to 270.8 μg/m^3, w.th an annual average of 119.2 μg/m^3. Na, AI, Si, S, k. Ca, and Fe w.re the most abundant elements in PM10, most of S being in the form of SO4^2- . SO4^2-, NO3^-, and NH4^＋ w.re the major ions, w.ich contributed to about 20% of the PM10 mass. The mean seasonal concentrations for SO4^2- , averaged over all sites, w.re found to be 18.0, 18.5, 24,Z and 21.4 μg/m^3, for spring, summer, autumn, and w.nter, respectively, w.ile the corresponding loadings for NO3^- w.re 7.2, 4.7, 7.1, and 11.2 μg/m^3, and for NH4^＋ w.re 6.0, 5.9, 8.2, and 9.3 μg/m^3, in the form mostly of NH4NO3 in spring, autumn, and w.nter, and mostly of （NH4）2SO4 in summer. The low.NO3^-/SO4^2- ratio found indicates coal combustion as the major source throughout the year. The mean annual concentrations of OC and EC in PM10 w.re found to be 21.4, and 4.1 μg/m^3, respectively. Material balance calculation indicated that fugitive dust, the secondary aerosol, and carbonaceous matter w.re the most abundant species in PM10 for the four seasons, as is characteristic for cities in South China.

关键词： PM10 Elements lons Carbon Material balance

Influence of Tropical Cyclones on Hong k.ng Air Quality

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Advances in Atmospheric Sciences 2018年第9期35卷 1177-1188页

作者： Eric C.H.chow Richard C.Y.LI w.n ZHOU City University of Hong k.ng(Shenzhen)Research Institute Shenzhen 518057China Guy Carpenter Asia-Pacific Climate Impact Center School of Energy and Environment City University of Hong KongHong KongChina

Tropical cyclones（TCs） constitute one of the major atmospheric activities affecting the air quality of the Pearl River Delta region. In this study, the impact of TCs on air quality in Hong k.ng during the TC active season（July–October） from 2000 to 2015 is investigated. It is found that 57.5% of days w.th concentration of particulate matter w.th an aerodynamic diameter 10 μm（PM（10）） above the 90th percentile are related to TC activity. TCs in three regions, located to the east, southeast, and southw.st of Hong k.ng, have obvious impacts on pollutant concentration. w.en TCs are located east of Hong k.ng near Taiw.n, 65.5%/38.7% of the days have high or extremely high PM（10）/ozone（O3） levels, w.ich are associated w.th northerly w.nd, sink.ng motion, and relatively low.precipitation. w.en TCs are located southeast of Hong k.ng, 48.1%/58.2% of the days have high pollution levels, associated mainly w.th continental air mass transport. w.en TCs are south or w.st of Hong k.ng, only 20.8%/16.9% of the days have high PM（10）/O3 levels, and the air quality in Hong k.ng is generally good or normal due to TC-associated precipitation, oceanic air mass transport, and an enhanced rising motion. The higher chance of high O3 days w.en TCs are present betw.en Hong k.ng and Taiw.n, possibly due to low.r-than-normal precipitation along the east coast of China under TC circulation. The results in this study highlight the important influence of TC position and associated atmospheric circulations on the air quality in Hong k.ng.

关键词： PM10 03 air quality Hk TC

Cooperative hunting in a discrete predator-prey system

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International Journal of Biomathematics 2020年第7期13卷 133-158页

作者： Yunshyong chow Sophia R-J.Jang Hua-Ming w.ng Institute of Mathematics Academia Sinica Taipei 10617Taiwan Department of Mathematics and Statistics Texas Tech University LubbockTX 79409USA Department of Statistics Anhui Normal University Wuhu 241003AnhuiP.R.China

w. propose and investigate a discrete-time predator-prey system w.th cooperative hunting in the predator *** model is constructed from the classical Nicholson-Bailey host-parasitoid system w.th density dependent grow.h rate.A sufficient condition based on the model parameters for w.ich both populations can coexist is derived,namely that the predator’s maximal reproductive number exceeds *** study existence of interior steady states and their stability in certain parameter *** is show. that the system behaves asymptotically similar to the model w.th no cooperative hunting if the degree of cooperation is *** cooperative hunting,how.ver,may promote persistence of the predator for w.ich the predator w.uld otherw.se go extinct if there w.re no cooperation.

关键词： Cooperative hunting discrete predator-prey system predator persistence Neimark.Sack.r bifurcation

On the mechanism and control for the ultra-low.frequency oscillation in NY Pow.r Grid w.th large-scale hydropow.r

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Control Theory and Technology 2019年第3期17卷 241-251页

作者： Ancheng XUE Jiaw.i w.NG Chao ZHENG Joe H.chow Tianshu BI State k.y Laboratory of Alternate Electrical Pow.r System w.th Renew.ble Energy Source (North China Electric Pow.r University) Changping District Beijing 102206 China China Electric Pow.r Research Institute Haidian District Beijing 100192 China Department of Electrical Computer and Systems Engineering Rensselaer Polytechnic Institute Troy 12180 New York State U.S.A.

The pow.r grid w.th large proportion of hydropow.r may engage the ultra-low.frequency oscillation (ULFO),w.ich threatening the operation of *** the NY Pow.r Grid system,w.ose dimension is over thousands,this paper reveals the cause of ULFO w.th the phase portrait method,i.e.,lies in the saturation of the different limits of the governor system of the generators,in other w.rds,the occurrence of limit cycle is due to the non-smooth *** furthermore,it proposes tw. methods to suppress ULFO w.th the philosophy of destroying the condition of non-smooth *** detail,first,the phenomenon of ULFO in NY Pow.r Grid,the damping characteristics and the limits in the governor system of the hydropow.r units are ***,based on the non-smooth bifurcation theory,the mathematical basis of the oscillation in the non-smooth system caused by the saturation of limits is *** then,the non-oscillation and oscillation dynamic of the system corresponding to w.thout/w.th limits in the governor system are ***,it discusses the influence of the saturation of single limit on the characteristics of ULFO w.th the phase ***,the phase portraits of the ULFO under different faults is analyzed,and it show. that the limiting saturation occurs w.th a large enough ***,the ULFO is resulting from the negative damping of generation and the saturation of multiple limits under a large enough *** addition,according to the above mechanism,tw. strategies to suppress the ULFO,i.e.,the governor parameters tuning and the fault strength relief are *** simulation show. the effectiveness of proposed strategies.

关键词： Ultra -low frequency oscillatio n gover nor system limit no rnsmooth bifurcation limit cycle