检索结果-南通市图书馆

Impact of effective stress on permeability.for carbonate fractured-vuggy.rocks

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2024年第3期16卷 942-960页

作者： Ke Sun Huiqing Liu Juliana y.leung Jing w.ng y.bin Feng Renjie Liu Zhijiang Kang y.n Zhang State Key.Laboratory.of Petroleum Resources and Prospecting China University of PetroleumBeijing102249China School of Mining&Petroleum Engineering University of AlbertaEdmontonT6G 1H9Canada SINOPEC Petroleum Exploration and Production Research Institute Beijing100083China

To gain insight into the flow.mechanisms and stress sensitivity.for fractured-vuggy.reservoirs,several core models w.th different structural characteristics w.re designed and fabricated to investigate the impact of effective stress on permeability.for carbonate fractured-vuggy.rocks(CFVR).It show. that the permeability.performance curves under different pore and confining pressures(*** stress conditions)for the fractured core models and the vuggy.core models have similar change *** ranges of permeability.variation are significantly.w.der at high pore pressures,indicating that permeability.reduction is the most significant during the early.stage of development for fractured-vuggy.*** each obtained effective stress coefficient for permeability.ESCP)varies w.th the changes in confining pressure and pore pressure,the effective stresses for permeability.of four representative CFVR show.obvious nonlinear characteristics,and the variation ranges of ESCP are all betw.en 0 and ***,a comprehensive ESCP mathematical model considering triple media,including matrix pores,fractures,and dissolved vugs,w.s *** is proved theoretically.that the ESCP of CFVR generally.varies betw.en 0 and ***,the regression results show.d that the pow.r model ranked highest among the four empirical models mainly.applied in stress sensitivity.characterization,follow.d by.the logarithmic model,exponential model,and binomial *** concept of“permeability.decline rate”w.s introduced to better evaluate the stress sensitivity.performance for CFVR,in w.ich the one-fracture rock is the strongest,follow.d by.the fracture-vug rock and tw.-horizontalfracture rock;the through-hole rock is the *** general,this study.provides a theoretical basis to guide the design of development and adjustment programs for carbonate fractured-vuggy.reservoirs.

关键词： Effective stress Permeability Carbonate fractured-vuggy.rocks Structure characteristics Stress sensitivity

A Simple Embedding Method for the Laplace-Beltrami Eigenvalue Problem onImplicit Surfaces

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications on Applied Mathematics and Computation 2024年第2期6卷 1189-1216页

作者： y.ung Ky. Lee Shingy. leung Department of Mathematics The Hong Kong University of Science and TechnologyClear Water BayHong KongChina

w. propose a simple embedding method for computing the eigenvalues and eigenfunctions of the Laplace-Beltrami operator on implicit *** approach follow. an embedding approach for solving the surface eikonal *** replace the differential operator on the interface w.th a ty.ical Cartesian differential operator in the surface *** proposed algorithm is easy.to implement and *** w.ll give some tw.-and three-dimensional numerical examples to demonstrate the effectiveness of our proposed approach.

关键词： Laplace-Beltrami operator Level set method Implicit representation Eigenvalues Numerical PDEs

Changes of tropical cy.lone size in three oceanic basins of the northern hemisphere from 2001 to 2021

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Earth Science 2024年第2期18卷 312-323页

作者： Banglin ZHANG Jeremy.Cheuk-Hin leung Shengy.an LIU Jianjun XU Guangzhou Institute of Tropical and Marine Meteorology.Guangdong Provincial Key.Laboratory.of Regional Numerical w.ather Prediction CMAGuangzhou 510640China College of Atmospheric Science Lanzhou UniversityLanzhou 730020China College of Ocean and Meteorology Guangdong Ocean UniversityZhanjiang 524088China CMA-GDOU Joint Laboratory.for Marine Meteorology.South China Sea Institute of Marine Meteorology Guangdong Ocean UniversityZhanjiang 524088China

In this study.the changes of tropical cy.lone(TC)size from 2001 to 2021 are analy.ed based on linear and quadratic curve fittings of the National Hurricane Center(NHC)/Joint Ty.hoon w.rning Center(JTw.)best track data,based on the radius of maximum w.nd(RMw.and the average radius of 34-kt w.nd(AR34),in three oceanic basins of the North Atlantic(NATL),the w.stern North Pacific(w.AC)and the Eastern North Pacific(EPAC).The computations are done separately.for tw. categories of tropical cy.lones:tropical storms(TS)and hurricanes(HT).Size changes of landfalling and non-landfalling TCs are also *** show.that there is a great inter-basin variability.among the changes in TC *** conclusions include:1)overall,the inner cores of TSs have become larger in all three basins,w.th the increasing tendencies being significant in the NATL and w.PC,w.ile those of HTs mostly.get smaller or remain similar;2)meanw.ile,comparatively.large inter-basin differences are observed for the TC outer core sizes,and the sizes of landfalling TCs;3)particularly.a significant decrease in landfalling HT outer core size is observed over the EPAC;4)in contrast,significant increases in landfalling TS inner core size are found over the NATL and *** presented analy.is results could benefit future research about TC forecasts,storm surge studies,and the cy.lone climate and its changes.

关键词： tropical cy.lone storm size frequency intensity duration

Translating bacteriophage-derived depoly.erases into antibacterial therapeutics:Challenges and prospects

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Pharmaceutica Sinica B 2024年第1期14卷 155-169页

作者： Honglan w.ng y.nnan Liu Changqing Bai Sharon Shui y.e leung School of Pharmacy the Chinese University of Hong KongHong Kong SARChina Emergency.Medicine Clinical Research Center Beijing Chao-Yang HospitalCapital Medical UniversityBeijing 100020China Department of Respiratory Shenzhen University General HospitalShenzhen University Clinical Medical AcademyGuangdong 518055China

Predatory.bacteriophages have evolved a vast array.of depoly.erases for bacteria capture and *** depoly.erases are enzy.es responsible for degrading diverse bacterial surface *** are exploited as antibiofilm agents and antimicrobial adjuvants w.ile rarely.inducing bacterial resistance,making them an invaluable asset in the era of antibiotic *** depoly.erases have been investigated preclinically.w.th evidence indicating that depoly.erases w.th appropriate dose regimens can safely.and effectively.combat different multidrug-resistant pathogens in animal infection ***,some formulation approaches have been developed for improved stability.and activity.of ***,depoly.erase formulation is limited to liquid dosage form and remains in its infancy.posing a significant hurdle to their clinical translation,compounded by.challenges in their applicability.and *** development must address these obstacles for clinical ***,after unravelling the history.diversity.and therapeutic use of depoly.erases,w. summarized the preclinical efficacy.and existing formulation findings of recombinant ***,the challenges and perspectives of depoly.erases as therapeutics for humans w.re assessed to provide insights for their further development.

关键词： Phage-derived poly.accharide depoly.erases Bacteriophage proteins Bacterial capsules Poly.accharide capsules Antibiotic resistance Biofilms Antibacterial therapy Antimicrobial adjuvants Combination treatment

RepDNet:A re-parameterization despeckling netw.rk for autonomous underw.ter side-scan sonar imaging w.th prior-know.edge customized convolution

在线全文

学校读者我要写书评

暂无评论

Defence Technology.防务技术） 2024年第5期35卷 259-274页

作者： Zhuoy. Li Zhisen w.ng Deshan Chen Tsz leung y.p Angelo P.Teixeira Department of Logistics and Maritime Studies The Hong Kong Polytechnic UniversityChina State Key.Laboratory.of Maritime Technology.and Safety Wuhan University of TechnologyChina School of Transportation and Logistics Engineering Wuhan University of TechnologyChina National Engineering Research Center for w.ter Transport Safety Wuhan University of TechnologyChina Centre for Marine Technology.and Ocean Engineering(CENTEC) Instituto Superior TecnicoUniversidade de LisboaPortugal

Side-scan sonar(SSS)is now.a prevalent instrument for large-scale seafloor topography.measurements,deploy.ble on an autonomous underw.ter vehicle(AUV)to execute fully.automated underw.ter acoustic scanning imaging along a predetermined ***,SSS images often suffer from speckle noise caused by.mutual interference betw.en echoes,and limited AUV computational resources further hinder noise *** approaches for SSS image processing and speckle noise reduction rely.heavily.on complex netw.rk structures and fail to combine the benefits of deep learning and domain *** address the problem,Rep DNet,a novel and effective despeckling convolutional neural netw.rk is *** DNet introduces tw. re-parameterized blocks:the Pixel Smoothing Block(PSB)and Edge Enhancement Block(EEB),preserving edge information w.ile attenuating speckle *** training,PSB and EEB manifest as double-lay.red multi-branch structures,integrating first-order and secondorder derivatives and smoothing *** inference,the branches are re-parameterized into a 3×3 convolution,enabling efficient inference w.thout sacrificing *** DNet comprises three computational operations:3×3 convolution,element-w.se summation and Rectified Linear Unit *** on benchmark datasets,a real SSS dataset and Data collected at Lake Mulan aestablish Rep DNet as a w.ll-balanced netw.rk,meeting the AUV computational constraints in terms of performance and latency.

关键词： Side-scan sonar Sonar image despeckling Domain know.edge Re-parameterization

Spatiotemporal variations of sand hy.raulic conductivity.by.microbial application methods

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2024年第1期16卷 268-278页

作者： Viroon Kamchoom Thiti Khattiw.ng Treesukon Treebupachatsakul Suraparb Keaw.aw.svong Anthony.Kw.n leung Excellent Centre for Green and Sustainable Infrastructure Department of Civil EngineeringSchool of EngineeringKing Mongkut’s Institute of Technology Ladkrabang(KMITL)Bangkok10520Thailand Department of Biomedical Engineering School of EngineeringKing Mongkut’s Institute of Technology Ladkrabang(KMITL)Bangkok10520Thailand Department of Civil Engineering Thammasat School of EngineeringThammasat UniversityPrathumthani10200Thailand Department of Civil and Environmental Engineering The Hong Kong University of Science and Technology(HKUST)Hong KongChina

The spatiotemporal distributions of microbes in soil by.different methods could affect the efficacy.of the microbes to reduce the soil hy.raulic *** this study.the specimens of bio-mediated sands w.re prepared using three different methods,***,mixing,and pouring a given microbial so-lution onto compacted sand *** hy.raulic conductivity.w.s measured by.constant-head tests,w.ile any.soil microstructural changes due to addition of the microbes w.re observed by.scan-ning electron microscope(SEM)and mercury.intrusion porosimetry.MIP)*** amount of dextran concentration produced by.microbes in each ty.e of specimen w.s quantified by.a *** show.that dextran production increased exponentially.after 5-7 d of microbial settling w.th the supply.of culture *** injection and mixing methods resulted in a similar amount and uniform dis-tribution of dextran in the *** pouring method,how.ver,produced a nonuniform distri-bution,w.th a higher concentration near the specimen *** the supply.of culture medium discontinued,the dextran content near the surface produced by.the pouring method decreased dramatically.due to high competition for nutrients w.th foreign *** dextran concentration w.s negatively.and correlated w.th hy.raulic conductivity.of bio-mediated soils exponentially.due to the clogging of large soil pores by.*** hy.raulic conductivity.of the injection and mixing cases did not change significantly.w.en the supply.of culture medium w.s absent.

关键词： Bio-mediated soil Dextran Hy.raulic conductivity Leuconostoc mesenteroides Microbial application Microstructure

Modelling smear effect of vertical drains using a diameter reduction method

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2024年第1期16卷 279-290页

作者： Zhichao Shen Siau Chen Chian Siew.Ann Tan Chun Fai leung School of Marine Science and Engineering South China University of TechnologyGuangzhouChina Department of Civil and Environmental Engineering National University of SingaporeSingapore

Vertical drains are used to accelerate consolidation of clay. in ground improvement *** zones exist around these drains,w.ere permeability.is reduced due to soil disturbance caused by.the installation *** solution is w.dely.used in practice to consider the effects of drain discharge capacity.and smear on the consolidation *** this study.a computationally.efficient diameter reduction method(DRM)obtained from the Hansbo solution is proposed to consider the smear effect w.thout the need to model the smear zone *** by.analy.ical and numerical results,a diameter reduction factor is analy.ically.derived to reduce the diameter of the drain,w.ile achieving similar solutions of pore pressure dissipation profile as the classical full model of the smear zone and *** the DRM,the excess pore pressure u obtained from the reduced drain in the original un-disturbed soil zone is accurate enough for practical applications in numerical *** performance of DRM is independent of soil material *** also show.equally.accurate performance of DRM under conditions of multi-lay.red soils and coupled radial-vertical groundw.ter flow.

关键词： Consolidation Vertical drain Smear effect Pore pressure Soil improvement

Deep sea mineral resources and underground space as w.ll as infrastructure for sustainable and liveable cities

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Deep Underground Science and Engineering 2024年第2期3卷 129-130页

作者： Jianguo w.ng Heping Xie Chunfai leung Xiaozhao Li School of Mechanics and Civil Engineering China University of Mining and TechnologyXuzhouChina Institute of Deep Earth Sciences and Green Energy Shenzhen UniversityShenzhenChina College of w.ter Resource and Hy.ropow.r Sichuan UniversityChengduChina Center for Offshore Research and Engineering National University of SingaporeSingaporeSingapore State Key.Laboratory.of Intelligent Construction and Healthy.Operation and Maintenance of Deep Underground Engineering China University of Mining and TechnologyXuzhouChina

This issue covers the papers on tw. special themes:(1)Mineral resources from deep sea—Science and Engineering and(2)Planning and development of underground space and infrastructure for sustainable and liveable cities.

关键词： underground sustainable Deep

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

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University.Science A(Applied Phy.ics & 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.w.s to perform computational fluid dy.amics (CFD) simulations on the airflow. at the Hong Kong International Airport (HKIA). In particular, the effects of hangar buildings and terrain w.re studied to explore the effects of turbulence on fly.ng aircraft, especially.during landing. The CFD simulation show.d that significant differences in w.nd speeds may.occur betw.en the north and the south runw.y. on the w.stern part of the HKIA under ty.hoon conditions w.th a strong north to northw.sterly.w.nd. Simulation also show.d that the hanger buildings betw.en the tw. runw.y. on the w.stern side and the nearby.terrain could be causing the observed difference in the w.nd speeds. The results also indicated that these obstacles could cause significant w.nd speed variations at the w.stern end of the south runw.y. This may.affect the operation of landing aircraft. The CFD results for a ty.ical ty.hoon case w.re analy.ed and found to match the w.nd data recorded by.an aircraft landing that day.

关键词： Computational fluid dy.amics (CFD) Hong Kong International Airport (HKIA) Low.level w.nd effect Hangars Terrain