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Stable Quantum Filters with Scattering Phenomena

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International Journal of Automation and computing 2008年第2期5卷 132-137页

作者： w.U.Ahamed c.Kambhampati Department of computer Science University of Hull

Quantum neural network filters for signal processing have received a lot of interest in the recent past. The implementations of these filters had a number of design parameters that led to numerical inefficiencies. At the same time the solution procedures employed were explicit in that the evolution of the time-varying functions had to be controlled. This often led to numerical instabilities. This paper outlines a procedure for improving the stability, numerical efficiency, and the accuracy of quantum neural network filters. Two examples are used to illustrate the principles employed.

关键词： Filter estimation quantum neural network probability density function nonlinear wave equation

Diagonalizations of Vector and Tensor Addition Theorems

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communications in computational Physics 2008年第9期4卷 797-819页

作者： B.He w.c.chew Department of Electrical and computer Engineering University of IllinoisUrbanaChampaignUrbanaIL 61801-2918USA. Faculty of Engineering The University of Hong KongHong Kong

Based on the generalizations of the Funk-Hecke formula and the Rayleigh plan-wave expansion formula,an alternative and succinct derivation of the addition theorem for general tensor field is *** new derivation facilitates the diagonalization of the tensor addition *** order to complete this derivation,we have carried out the evaluation of the generalization of the Gaunt coefficient for tensor *** vector fields(special case of tensor fields)are very useful in practice,we discuss vector multipole fields and vector addition theorem in *** work is important in multiple scattering and fast algorithms in wave physics.

关键词： Addition theorem vector field tensor field fast algorithm.

Extraction of catechins and caffeine from different tealeaves and comparison with micellar electrokinetic chromatography

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chinese Science Bulletin 2003年第22期48卷 2438-2443页

作者： SONGGuanqun LINJinming QuFeng c.w.Huie ResearchcenterforEco-EnvironmentalSciences ChineseAcademyofSciencesBeijing100085China Departmentofchemistry HongKongBaptistUniversityKowloonTongHongKongChina

This work describes the simultaneous deter- mination of catechins and caffeine in green, black tealeaves and canned tea-drink using micellar electrokinetic chromatography. The catechins analyzed include (+)-catechin, (-)- epicatechin, (-)-epigallocatechin, (-)-epicatechin gallate and (-)-epigallocatechin gallate. Using UV absorption method at 280 nm, the limits of detections of catechins and caffeine are 10-6 mol/L, which is suitable for the real sample determination. Using this analytical method, the extraction of these compounds from the tealeaves with hot water is compared under different temperatures. The effects of temperature on the amount of catechins and caffeine extracted are evident, showing that (-)-epigallocatechin gallate is the most easiest to be extracted at 100℃. The stability of catechins and caffeine in stocking solution of tea-drink at 4℃ is also compared on five consecutive days. The contents of catechins and caffeine in green and black teas are discussed and the difference of the content between different tealeaves can provide a reference for the assessment of tea quality.

关键词：咖啡因儿茶酚萃取法茶叶胶束电动套色版

A critical review:emerging bioeconomy and waste-to-energy technologies for sustainable municipal solid waste management

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waste Disposal and Sustainable Energy 2019年第3期1卷 151-167页

作者： To-Hung Tsui Jonathan w.c.wong Department of Biology Institute of Bioresource and AgricultureSino-Forest Applied Research Centre for Pearl River Delta EnvironmentHong Kong Baptist UniversityKowloon TongHong KongChina

Municipal solid waste(MSw)management has emerged as probably the most pressing issue many governments nowadays are ***,waste-to-Energy(wtE)is mostly associated with incineration,but now,with the emergence of the bioeconomy,it embraces a broader definition comprising any processing technique that can generate electricity/heat or produce a waste-derived *** the ambit of the circular economy many nations are looking for,additional effort must be made to be sure of acquiring the most updated information and paving a sustainable path for managing MSw in such a *** this regard,we have undertaken a critical review of various technologies,with their updated progress,involved in the exploitation of MSw as a renewable resource,along with the critical advantages and limitations on energy and material cycling for sustainable MSw ***,the most widely used method,is nowadays difficult to further apply due to its dubious reputation and social ***,to address the organic fraction of MSw which currently is mostly unrecycled and causes disposal issues,the biological approach presents an attractive *** new emphasis of bioeconomy leads us to understand how environmental biotechnologies should be better connected/integrated for more sustainable MSw *** article is concluded with advances of future prospects,which can serve as a timely reminder to encourage competent authorities/researchers to work towards further improvement of the present MSw management system.

关键词： Municipal solid waste management Sustainability circular economy Bioeconomy waste-to-energy Anaerobic digestion

Risk management for sulfur dioxide abatement under multiple uncertainties

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Frontiers of Earth Science 2016年第1期10卷 87-107页

作者： c. DAI w. SUN Q. TAN Y. LIU w.T. LU H.c. GUO college of Environmental Science and Engineering Peking University Beijing 100871 China Institute for Energy Environment and Sustainable Communities University of Reginal Regina Saskatchewan S4S 7H9 Canada college of water Resources & civil Engineering China Agricultural University Beijing 100083 China

In this study, interval-parameter programming, two-stage stochastic progranaming （TSP）, and conditional value-at-risk （cVaR） were incorporated into a general optimization framework, leading to an interval-parameter cVaR-based two-stage programming （IcTP） method. The IcTP method had several advantages：（i） its objective function simultaneously took expected cost and risk cost into consideration, and also used discrete random variables and discrete intervals to reflect uncertain properties; （ii） it quantitatively evaluated the right tail of distributions of random variables which could better calculate the risk of violated environmental standards; （iii） it was useful for helping decision makers to analyze the trade-offs between cost and risk; and （iv） it was effective to penalize the second-stage costs, as well as to capture the notion of risk in stochastic programming. The developed model was applied to sulfur dioxide abatement in an air quality management system. The results indicated that the IcTP method could be used for generating a series of air quality management schemes under different risk-aversion levels, for identifying desired air quality management strategies for decision makers, and for considering a proper balance between system economy and environmental quality.

关键词： risk management conditional value-at-risk,interval optimization two-stage programming uncertainty,air quality management

Effect of terrain and building structures on the airflow in an airport

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2012年第6期13卷 461-468页

作者： Dennis Y. c. LEUNG w. Y. LO w. Y. cHOw P. w. cHAN Department of Mechanical Engineering The University of Hong Kong Hong Kong China Hong Kong Observatory Hong Kong China

The aim of this study was to perform computational fluid dynamics (cFD) simulations on the airflows at the Hong Kong International Airport (HKIA). In particular, the effects of hangar buildings and terrain were studied to explore the effects of turbulence on flying aircraft, especially during landing. The cFD simulation showed that significant differences in wind speeds may occur between the north and the south runways on the western part of the HKIA under typhoon conditions with a strong north to northwesterly wind. Simulation also showed that the hanger buildings between the two runways on the western side and the nearby terrain could be causing the observed difference in the wind speeds. The results also indicated that these obstacles could cause significant wind speed variations at the western end of the south runway. This may affect the operation of landing aircraft. The cFD results for a typical typhoon case were analyzed and found to match the wind data recorded by an aircraft landing that day.

关键词： computational fluid dynamics (cFD) Hong Kong International Airport (HKIA) Low-level wind effect Hangars Terrain

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chinese Annals of Mathematics,Series B 2002年第2期23卷 149-164页

作者： c.BARDOS Y.GUO w.STRAUSS Universite DivisionDepartment Denis Diderot and LAN Universite Pierre et Marie CurieParisFrance.of Applied MathematicsBrown UniversityProvidenceRhode Island 02912U?

The authors investigate the stability of a steady ideal plane flow in an arbitrary domain in terms of the L^2 norm of the vorticity. Linear stability implies nonlinear instability provided the growth rate of the linearized system exceeds the Liapunov exponent of the flow. In contrast,a maximizer of the entropy subject to constant energy and mass is stable. This implies the stability of certain solutions of the mean field equation.

关键词： Stable ideal plane flows Unstable ideal plane flows Liapunov exponent

On the microstructural origin of premature failure of creep strength enhanced martensitic steels

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Journal of Materials Science & Technology 2021年第28期87卷 269-279页

作者： J.Li c.Xu G.Zheng w.J.Dai c.c.Bu G.chen MIIT Key Laboratory of Advanced Metallic and Intermetallic Materials Technology Engineering Research Center of Materials Behavior and DesignMinistry of EducationNanjing University of Science and TechnologyNanjing210094China Nanjing Jiuzhu New Materials Institute co. Ltd.Nanjing211151China condensed Materials Laboratory co. Ltd.Yangzhou225200China Yangzhou chengde Steel Pipe co. Ltd.Yangzhou225200China

The creep strength enhanced martensitic steels are key material for the main power generating units in ultra-supercritical *** on the evaluation of their creep rupture life show there is an overestimation of rupture life after long-term creep,which is known as premature ***,the microstructural origin of the premature failure remains *** in this study,we have carefully investigated the microstructural transformations and their influences on creep rupture behavior,showing that the evolution of martensite and M_(23)c_(6) carbides as well as Laves phase are responsible for the premature *** using multi-step TTP-LMP method,we confirmed a three-stage creep rupture behavior under different stress *** quantitative analysis showed that the coarsening of M_(23)c_(6) carbides and recovery of martensite exert equal and dominant effects on the premature failure in the medium stress region,while precipitation and coarsening of Laves phase are responsible for the premature failure in the low stress region.

关键词： creep strength enhanced martensitic steel Premature failure M_(23)c_(6)carbides Martensite recovery Laves phase

Long-Term Trends in Extreme Temperatures in Hong Kong and Southern china

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Advances in Atmospheric Sciences 2011年第1期28卷 147-157页

作者： T.c.LEE E.w.L.GINN Hong Kong Observatory

The observed long-term trends in extreme temperatures in Hong Kong were studied based on the meteorological data recorded at the Hong Kong Observatory Headquarters from 1885-2008. Results show that, over the past 124 years, the extreme daily minimum and maximum temperatures, as well as the length of the warm spell in Hong Kong, exhibit statistically significant long-term rising trends, while the length of the cold spell shows a statistically significant decreasing trend. The time-dependent return period analysis also indicated that the return period for daily minimum temperature at 4°c or lower lengthened considerably from 6 years in 1900 to over 150 years in 2000, while the return periods for daily maximum temperature reaching 35°c or above shortened drastically from 32 years in 1900 to 4.5 years in 2000. Past trends in extreme temperatures from selected weather stations in southern china from 1951-2004 were also assessed. Over 70% of the stations studied yielded a statistically significant rising trend in extreme daily minimum temperature, while the trend for extreme maximum temperatures was found to vary, with no significant trend established for the majority of stations.

关键词： extreme temperature long-term trend Hong Kong southern china