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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第1期10卷 1-6页

作者： Michael k.H.leung k.t-ying CHAN Department of Mechanical Engineering the University of Hong Kong

Soil in a cold region is subject to frequent freezing and thaw.ng *** frozen for a prolonged period may cause adverse freeze damage to the plants due to cell dehydration or root cell *** is important to understand the detailed heat transfer behaviors of the freezing and thaw.ng processes to prevent freeze damage,and to devise proper mitigation measures for effective pot planting in cold regions.A theoretical model w.s developed to analyze the transient moving phase-change interface heat transfer in the freezing and thaw.ng of porous potting *** theoretical derivation is based on the assumption that the soil freezes completely at a single *** poromechanic effects on heat transfer behavior w.re *** spatial domain of the problem w.s simplified to a 1D spherical coordinate system w.th variation in the radial ***'s function w.s applied to solve for the time-dependent body *** w.re conducted for validation of the theoretical *** agreement betw.en the theoretical predictions and experimental measurements w.s *** theoretical model developed can be easily used to determine the sensitivity of various parameters in the freezing/thaw.ng processes,e.g.,thermal properties of soil,ambient temperature,and planting pot size.

关键词：多孔隙土热物性变点温度土力学

Microw.ve heating as a universal method to transform confined molecules into armchair graphene nanoribbons

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Nano Research 2023年第7期16卷 10644-10651页

作者： Haoyuan Zhang Yingzhi Chen k.npeng Tang Ziheng Lin Xuan Li Hongw.i Zhang Yifan Zhang Chi Ho w.ng Chi w.h leung Chee leung Mak.Yuan Hu w.ili Cui k.cheng Cao Lei Shi State k.y Laboratory of Optoelectronic Materials and Technologies Nanotechnology Research CenterGuangdong Province Key Lab of Display Material and TechnologySchool of Materials Science and EngineeringSun Yat-sen UniversityGuangzhou 510275China Huzhou k.y Laboratory of Environmental Functional Materials and Pollution Control School of EngineeringHuzhou UniversityHuzhou 313000China Department of Industrial and Systems Engineering Research Institute for Advanced ManufacturingThe Hong Kong Polytechnic UniversityHong Kong 999077China Department of Applied Physics The Hong Kong Polytechnic UniversityHong Kong 999077China Shanghai k.y Laboratory of High-resolution Electron Microscopy ShanghaiTech UniversityShanghai 201210China

Armchair graphene nanoribbons(AGNRs)w.th sub-nanometer w.dth are potential materials for the fabrication of novel nanodevices thank. to their moderate direct band *** are usually synthesized by polymerizing precursor molecules on substrate ***,it is time-consuming and not suitable for large-scale *** can also be grow. by transforming precursor molecules inside single-w.lled carbon nanotubes(Sw.NTs)via furnace annealing,but the obtained AGNRs are normally *** this w.rk.microw.ve heating is applied for transforming precursor molecules into *** fast heating process allow. synthesizing the AGNRs in *** different molecules w.re successfully transformed into AGNRs,suggesting that it is a universal *** importantly,as demonstrated by Raman spectroscopy,aberrationcorrected high-resolution transmission electron microscopy and theoretical calculations,less tw.sted AGNRs are synthesized by the microw.ve heating than the furnace *** results reveal a route for rapid production of AGNRs in large scale,w.ich w.uld benefit future applications in novel AGNRs-based semiconductor devices.

关键词： armchair graphene nanoribbons(AGNRs) microw.ve heating single-w.lled carbon nanotubes(Sw.NTs) Raman spectroscopy

Unsupervised ore/w.ste classification on open-cut mine faces using close-range hyperspectral data

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Geoscience Frontiers 2023年第4期14卷 89-99页

作者： Lloyd w.ndrim Arman Melk.myan Richard J.Murphy Anna Chlingaryan Raymond leung Rio Tinto Centre for Mine Automation Australian Centre for Field RoboticsThe University of SydneySydney 2006Australia

The remote mapping of minerals and discrimination of ore and w.ste on surfaces are important task. for geological applications such as those in *** task. have become possible using ground-based,close-range hyperspectral sensors w.ich can remotely measure the reflectance properties of the environ-ment w.th high spatial and spectral ***,autonomous mapping of mineral spectra mea-sured on an open-cut mine face remains a challenging problem due to the subtleness of differences in spectral absorption features betw.en mineral and rock.classes as w.ll as variability in the illumination of the *** additional layer of difficulty arises w.en there is no annotated data available to train a supervised learning algorithm.A pipeline for unsupervised mapping of spectra on a mine face is pro-posed w.ich draw. from several recent advances in the hyperspectral machine learning *** proposed pipeline brings together unsupervised and self-supervised algorithms in a unified system to map minerals on a mine face w.thout the need for human-annotated training *** pipeline is eval-uated w.th a hyperspectral image dataset of an open-cut mine face comprising mineral ore martite and non-mineralised *** combined system is show. to produce a superior map to its constituent algo-rithms,and the consistency of its mapping capability is demonstrated using data acquired at tw. differ-ent times of day.

关键词： Hyperspectral imaging Mineral mapping Open-cut mine face Machine learning Convolutional neural netw.rk. Illumination invariance

Aluminum-air battery w.th cotton substrate:Controlling the discharge capacity by electrolyte pre-deposition

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Green Energy & Environment 2023年第3期8卷 757-766页

作者： w.nding Pan Yifei w.ng Holly Y.H.k.0}k.Dennis Y.C.leung Department of Mechanical Engineering The University of Hong KongHong KongChina

Conventional Al-air battery has many disadvantages for miniw.tt applications,such as the complex w.ter management,bulk. electrolyte storage and potential leak.ge ***,the self-corrosion of Al anode continues even w.en the electrolyte flow.is stopped,leading to great Al *** tack.e these issues,an innovative cotton-based aluminum-air battery is developed in this *** of flow.ng alk.line solution,cotton substrate pre-deposited w.th solid alk.line is used,together w.th a small w.ter reservoir to continuously w.t the cotton and dissolve the alk.line *** this manner,the battery can be mechanically recharged by replacing the cotton substrate and refilling the w.ter reservoir,w.ile the thick.aluminum anode can be reused for tens of times until complete *** cotton substrate show. excellent ability for the storage and transportation of alk.line electrolyte,leading to a high peak.pow.r density of 73 mw.cm^(-2) and a high specific energy of 930 mw.h g^(-1).Moreover,the battery discharge capacity is found to be linear to the loading of pre-deposited alk.line,so that it can be precisely controlled according to the mission profile to avoid Al ***,a tw.-cell battery pack.w.th common w.ter reservoir is developed,w.ich can provide a voltage of 2.7 V and a pow.r output of 223.8 *** further scaling-up and stack.ng,this cotton-based Al-air battery system w.th low.cost and high energy density is very promising for recharging miniw.tt electronics in the outdoor environment.

关键词： Al-air battery Cotton-based Electrolyte pre-deposition Capacity control Miniw.tt electronics

Extended Impact of Cold Air Invasions in East Asia in Response to a w.rm South China Sea and Philippine Sea

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Advances in Atmospheric Sciences 2023年第3期40卷 531-540页

作者： Marco Y.-T.leung Dongxiao w.NG w.n ZHOU Yuntao JIAN School of Marine Sciences Sun Yat-Sen UniversityZhuhai 519082China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519000China Department of Atmospheric and Oceanic Sciences&Institute of Atmospheric Sciences Fudan UniversityShanghai 200438China Guy Carpenter Asia-Pacific Climate Impact Centre Center for Ocean Research in Hong Kong and Macao(CORE)School of Energy and EnvironmentCity University of Hong KongHong KongChina

During boreal w.nter,the invasion of cold air can lead to remark.ble temperature drops in East Asia w.ich can result in serious socioeconomic ***,w. find that the intensity of strong synoptic cold days in the East China Sea and Indochina Peninsula are *** enhanced synoptic cold days in these tw. regions are attributed to surface w.rming over the South China Sea and Philippine Sea(SCSPS).The oceanic forcing of the SCSPS on the synoptic cold days in the tw. regions is verified by numerical *** w.rming of the SCSPS enhances the baroclinicity,w.ich intensifies meridional w.nd and cold advection on synoptic *** leads to a more extended region that is subject to the influence of cold invasion.

关键词： ocean w.rming extra-tropical cyclones baroclinicity temperature w.iplash

Neonates are more vulnerable to symptomatic SARS-CoV-2 infection than children:a matched cohort study in Brazil

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w.rld Journal of Pediatrics 2022年第6期18卷 437-442页

作者： Char leung Luisamanda Selle k.rina Mary de Paiva Patricia Haas School of Clinical Medicine Addenbrooke’s HospitalUniversity of CambridgeHills RoadCambridgeCB20QQUK Department of Speech Language and Hearing SciencesFederal University of Santa CatarinaFlorianópolisBrazil

As the causative agent of coronavirus disease 2019(COVID-19),severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)is one of the seven coronaviruses pathogenic to human and one of the four human coronaviruses that cause acute respiratory disease *** it affects people of all age groups,the risk.of mortality is *** in many other diseases,elderly patients have a higher risk.of infection,mortality,and morbidity[1].w.ile it is a common belief that children fare better than adult and elderly,recent evidence merged that neonates and infants are associated w.th a higher risk.of mortality and morbidity,compared to children and adolescents[2,3].For instance,a cross-country study found that the infection–fatality ratio of those agedw.s found to be 0.003,higher than those aged betw.en 5 and 14 years of 0.001 despite low.r than those aged betw.en 20 and 59 that vary betw.en 0.006 and 0.323[4].How.ver,w.ether this holds true in the risk.of infection is not yet *** this back.round,the present w.rk.aimed to verify w.ether neonates are more susceptible to COVID-19 using publicly available data of all polymerase chain reaction(PCR)tests performed in the state of São Paulo of Brazil.

关键词： mortality infection acute

Gestational age-specific neonatal mortality in Hong k.ng:a population-based retrospective study

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w.rld Journal of Pediatrics 2023年第2期19卷 158-169页

作者： Xue-Lian w.ng Eman leung Genevieve Po Gee Fung Hugh Simon Lam Department of Neonatology Guangzhou Women and Children’s Medical CenterGuangzhou Medical UniversityGuangdong Provincial Clinical Research Center for Child HealthGuangzhouChina Department of Paediatrics Faculty of MedicineThe Chinese University of Hong KongHong Kong SARChina The Jock.y Club School of Public Health and Primary Care Faculty of MedicineThe Chinese University of Hong KongHong Kong SARChina Department of Paediatrics 6/F Lui Che Woo Clinical Sciences BuildingPrince of Wales HospitalSha TinNew TerritoriesHong Kong SARChina

Back.round The neonatal period is the most vulnerable period during childhood,w.th the risk.of death being the highest even in developed countries/*** k.ng’s neonatal mortality(1‰)is among the w.rld’s low.st and has remained similar for 15 *** study aimed to explore neonatal deaths in Hong k.ng in detail and determine w.ether neonatal mortality is reducible at such a low.*** Live births in public hospitals in Hong k.ng during 01 Jan 2006–31 Dec 2017 w.re *** data w.re extracted from the electronic medical *** age-specific mortality w.s calculated,and the trends w.re analyzed using the Cochran–Armitage trend *** of death w.re summarized,and risk.factors w.re identified in multivariate logistic regression *** In 490,034 live births,755 cases(1.54‰)died during the neonatal period,and 293(0.6‰)died during the post-neonatal *** neonatal mortality remained similar overall(P=0.17)and among infants born at 24–29 w.ek.’gestation(P=0.4),w.ile it decreased in those born at 23(P=0.04),30–36(Pw.ek.’*** born atw.ek.’gestation accounted for a significantly increased proportion among cases w.o died(27.6%to 51.9%),w.th hemorrhagic conditions(24%)being the leading cause of *** anomalies w.re the leading cause of death in neonates born≥27 w.ek.’gestation(52%),but its cause-specific mortality decreased(P=0.002,0.6‰to 0.41‰),w.th most of the decrease attributed to trisomy 13/18 and multiple *** Reduction of neonatal mortality in developed regions may heavily rely on improved quality of perinatal and neonatal care among extremely preterm infants.

关键词： Cause of death Neonatal mortality Population based Risk.factor Trend

Strengthened Regulation of the Onset of the South China Sea Summer Monsoon by the Northw.st Indian Ocean w.rming in the Past Decade

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Advances in Atmospheric Sciences 2022年第6期39卷 943-952页

作者： Yang AI Ning JIANG w.ihong QIAN Jeremy Cheuk.Hin leung Yanying CHEN State k.y Laboratory of Severe w.ather(LASw.and Institute of Climate System Chinese Academy of Meteorological SciencesBeijing 100081China Department of Atmospheric and Oceanic Sciences Peking UniversityBeijing 100871China Guangzhou Institute of Tropical and Marine Meteorology/Guangdong Provincial k.y Laboratory of Regional Numerical w.ather Prediction China Meteorological AdministrationGuangzhou 510641China School of Marine Sciences Nanjing University of Information Science&TechnologyNanjing 210044China

Traditionally,a delayed(early)onset of the South China Sea summer monsoon(SCSSM)has been observed to follow.a w.rm(cold)El Niño-Southern Oscillation(ENSO)event in w.nter,supporting high seasonal predictability of SCSSM ***,the empirical seasonal forecasting sk.ll of the SCSSM onset,solely based on ENSO,has deteriorated since ***,unexpected delayed onsets of the SCSSM have also occurred in the past *** attribute these changes to the Northw.st Indian Ocean(Nw.O)w.rming of the sea *** Nw.O w.rming has teleconnections related to(1)suppressing the seasonal convection over the South China Sea,w.ich w.ak.ns the impacts of ENSO on SCSSM onset and delays the start of SCSSM,and(2)favoring more high-frequency,propagating moist convective activities,w.ich enhances the uncertainty of the seasonal prediction of SCSSM onset *** results yield insight into the predictability of the SCSSM onset under the context of uneven ocean w.rming operating w.thin the larger-scale back.round state of global climate change.

关键词： Indian Ocean South China Sea summer monsoon monsoon onset ENSO

Potential Use of Strain Hardening ECC in Permanent Formw.rk.w.th Small Scale Flexural Beams

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Journal of w.han University of Technology(Materials Science) 2009年第3期24卷 482-487页

作者：李贺东 Christopher k.Y leung Department of Civil Engineering Hong Kong University of Science and Technology

Utilizing pre-cast ECC panels as participating permanent formw.rk.of concrete members, and the validity of using ECC to disperse the single crack.in concrete into multiple ones in ECC w.re studied. In the process, totally tw. k.nds of ECC w.th different tensile properties, 7 series of flat panels w.th different top surface figures and 3 U-shape panels w.th different inner surface forms w.re investigated. To evaluate the performance of the permanent formw.rk., small ECC-concrete composite beams w.re cast and tested mechanically. The 4-point bending test results show.that the use of pre-cast ECC panels as permanent formw.rk.can significantly improve the load capacity and toughness of a concrete member, effectively dispersing single w.dely opened crack.in concrete into multiple ones in ECC. Most permanent formw.rk. show.perfect bond w.th the concrete cast on them, w.ile the ones w.th partially debonded zone achieve the best mechanical performance. The U-shape permanent formw.rk. show.better performances than the flat ones, achieving much betler improvements in both the load capacity and toughness, together w.th better crack.w.dth control.

关键词： pseudo strain hardening cementitious composites permanent formw.rk toughness crack

Is artificial intelligence the final answ.r to missed polyps in colonoscopy?

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w.rld Journal of Gastroenterology 2020年第35期26卷 5248-5255页

作者： Thomas k.L Lui w.i k.leung Department of Medicine Queen Mary HospitalUniversity of Hong KongHong KongChina

Lesions missed by colonoscopy are one of the main reasons for post-colonoscopy colorectal cancer,w.ich is usually associated w.th a w.rse *** the adenoma miss rate could be as high as 26%,it has been noted that endoscopists w.th higher adenoma detection rates are usually associated w.th low.r adenoma miss *** intelligence(AI),particularly the deep learning model,is a promising innovation in *** studies have show. that AI is not only accurate in colorectal polyp detection but can also reduce the miss ***,the application of AI in real-time detection has been hindered by heterogeneity of the AI models and study design as w.ll as a lack.of long-term ***,w. discussed the principle of various AI models and systematically review.d the current data on the use of AI on colorectal polyp detection and miss *** limitations and future prospects of AI on colorectal polyp detection are also discussed.

关键词： Artificial intelligence Adenoma Colonoscopy Colorectal cancer Polyps