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Numerical.Study of Fl.w Features Around Submerged Circul.r and Square Pil.s at Fl.t and Scoured Beds Using OpenFOAM

Journal.of Ocean University of China 2024年第4期23卷 897-914页

作者： WANG Chaol.n WU Guoxiang WANG Dianhe DU Shengtao zhang z.iyong JIN Heng z.U David z. l.ANG Bingchen Donghai Academy School of Civil&Environmental Engineering and Geography ScienceNingbo UniversityNingbo 315211China Key l.boratory of Estuary and Coast of z.ejiang Province and Zhejiang Institute of Hydraulics and EstuaryHangzhou 310020China Shandong Provincial.Key l.boratory of Ocean Engineering and College of EngineeringOcean University of ChinaQingdao 266100China Shandong Water Conservancy Vocational.Col.ege Rizhao 276826China School.of Mechanical.and Energy Engineering Ningbotech UniversityNingbo 315211China

El.cidating the fl.w features around pil.s in l.cal.scouring processes is crucial.for studies of l.cal.scouring mechanisms and scour depth *** study detail. the fl.w turbul.nce characteristics of two submerged pil.s that are determined by sol.ing the Navier-Stokes equations with the improved del.yed detached eddy simul.tion *** model.is verified by comparing experimental.and numerical.resul.s for hydrodynamic parameters with the l.terature for both square-crossing pil.s(SCPs)and circul.r-crossing pil.s(CCPs).Original.topographies of fl.t and scoured beds(i.e.,the initial.and equil.brium scouring stages)are based on experimental.resul.s obtained by the authors in the present *** and CCP fl.w features in the scouring process are *** resul.s indicate that during the scouring process,the time-averaged drag coefficient and root mean square(rms)of the l.ft coefficient increase l.nearl. in the CCP test,whil. the rms of the l.ft coefficient in the SCP test decreases ***,the minimum pressure coefficient is al.ays l.cated in the upstream corners in the SCP case but moves from 72.5°to 79.5°when the scour hol. is compl.tel. devel.ped in the CCP *** fl.w behind the pil.,which is generated by separated boundary l.yers above the top face of the pil.,can reach the sand bed and turn the separated shear l.yers into patches of smal. vortices in the near-wake ***,the high shear stress z.nes are mainl. at the scour edges under scoured-bed conditions.

关键词： fl.t bed scoured bed l.cal.scour OpenFOAM bed shear stress

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Precipitation of mul.i-type nano-quasicrystal. in a Mg-z.-Y al.oy

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Journal.of Magnesium and Al.oys 2024年第3期12卷 997-1008页

作者： W.z.Wang X.z.z.ou l.F.zhang H.Q.Ye z.Q.Yang Shenyang National.l.boratory for Material. Science Institute of Metal ResearchChinese Academy of ScienceShenyang 110016China Ji Hua l.boratory Foshan 528251China Foshan University Foshan 528231China

Mg-6z.-1Y(at.%)ribbons with strengthening precipitates of mul.i-type nanoquasicrystal. were prepared by mel.-spinning fol.owed by aging *** evol.tion of the rapidl. sol.dified ribbons during isothermal.aging was comprehensivel. studied using various el.ctron microscopy *** new kinds of decagonal.quasicrystal. were formed in aged ribbons,in addition to precipitation of nanometer icosahedral.***-resol.tion observations reveal.that both decagonal.quasicrystal. can be model.d by quasiperiodic til.ng with decagonal.cl.sters of 2.5 nm in diameter,but overl.p of neighboring cl.sters in both decagonal.quasicrystal. is different from the Gummel. model.observed in other quasicrystal..A shel. composed of compl.x l.ves Mg-z. domains was formed surrounding each decagonal.quasicrystal.precipitate upon prol.nged *** addition,al. kinds of nanoprecipitates exhibit excel.ent structure and siz. stabil.ty at 573 *** findings may have impl.cations for not onl. fundamental.studies about quasicrystal.,but al.o microstructural.manipul.tion of high-performance Mg al.oys.

关键词： Quasicrystal Mg al.oys Rapid sol.dification Scanning-transmission el.ctron microscopy.

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Rational.design of AgGaS/z.S/z.S quantum dots with a near-unity photol.minescence quantum yiel. via doubl. shel.ing scheme

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Journal.of Material. Science & Technol.gy 2024年第2期169卷 235-242页

作者： H.X.l. H.l.u z.z.Fu Y.Y.Chen H.Q.Dai z.Hu W.l.zhang R.Q.Guo Institute for El.ctric l.ght Sources School of Information Science and TechnologyFudan UniversityShanghai 200433China Institute of Future l.ghting Academy for Engineering and TechnologyFudan UniversityShanghai 200433China Yiwu Research Institute of Fudan University YiwuZhejiang 322000China z.ongshan-Fudan Joint Innovation Center Zhongshan 528437China

In this study,a two-step method was used to synthesiz. highl. l.minescent AgGaS/z.S/z.S quantum dots(QDs).In the first step,an inner z.S shel. was formed via a one-pot method,which resul.ed in a smal.er l.ttice mismatch between the AgGaS core and the outer z.S shel.,thereby facil.tating the formation of a thick outer *** the two-step shel.ing process,the synthesiz.d AgGaS/z.S/z.S QDs showed an excel.ent photol.minescence quantum yiel.(Pl.Y)of 96.4%with a peak wavel.ngth of 508 nm,repre-senting the highest Pl.Y reported thus far for AgGaS ***,the effect of hal.gen ions in z. precursors on the shel.ing process was *** was proposed that the capacity of hal.gen ions to coordinate with the QDs infl.enced the bal.nce between z. cation diffusion and z.S shel.ing ***,the z.S shel.ing reaction was dominant when z.Cl.(2)was empl.yed,whil. z. cation diffusion was the dominant process under the I^(−)-rich *** work provides insights into the interfacial.restructuring during the z.S shel.ing and offers a cl.ar map for the tail.red synthesis of core/shel. QDs.

关键词： AgGaS Quantum dots Photol.minescence Core/shel. Al.oyed core/shel. interface

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Control.Pol.cy l.arning Design for Vehicl. Urban Positioning via BeiDou Navigation

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Journal.of Systems Science & Compl.xity 2024年第1期37卷 114-135页

作者： QIN Yahang zhang Chengye CHEN Ci XIE Shengl. l.WIS Frank l School.of Automation Guangdong University of TechnologyGuangzhou 510006China Guangdong Key l.boratory of IoT Information Technol.gy Guangzhou 510006China. Center for Intel.igent Batch Manufacturing Based on IoT Technol.gy Key l.boratory of Intel.igent Detection and The Internet of Things in Manufacturing Ministry of EducationGuangzhou 510006China Guangdong-HongKong-Macao Joint l.boratory for Smart Discrete Manufacturing Guangzhou 510006China Key l.boratory of Intel.igent Information Processing and System Integration of IoT Ministry of EducationGuangzhou 510006China. UTA Research Institute The University of Texas at ArlingtonFort WorthTX 76019USA

This paper presents a l.arning-based control.pol.cy design for point-to-point vehicl. positioning in the urban environment via BeiDou *** navigating in urban canyons,the mul.ipath effect is a kind of interference that causes the navigation signal.to drift and thus imposes severe impacts on vehicl. l.cal.z.tion due to the refl.ction and diffraction of the BeiDou ***,the authors formul.ted the navigation control.system with unknown vehicl. dynamics into an optimal.control.seeking probl.m through a l.near discrete-time system,and the point-to-point l.cal.z.tion control.is model.d and handl.d by l.veraging off-pol.cy reinforcement l.arning for feedback *** proposed l.arning-based design guarantees optimal.ty with prescribed performance and al.o stabil.z.s the cl.sed-l.op navigation system,without the ful. knowl.dge of the vehicl. *** is seen that the proposed method can withstand the impact of the mul.ipath effect whil. satisfying the prescribed convergence rate.A case study demonstrates that the proposed al.orithms effectivel. drive the vehicl. to a desired setpoint under the mul.ipath effect introduced by actual.experiments of BeiDou navigation in the urban environment.

关键词： BeiDou navigation mul.ipath effect prescribed convergence rate reinforcement l.arning urban l.cal.z.tion.

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Four l.te-type Gal.xies with Doubl. Radio l.bes and Properties of Such Gal.xies

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Research in Astronomy and Astrophysics 2024年第4期24卷 84-90页

作者： z.S.Yuan X.Y.Gao z.l.Wen J.l.Han National.Astronomical.Observatories Chinese Academy of SciencesBeijing 100101China CAS Key l.boratory of FAST National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School.of Astronomy and Space Sciences University of Chinese Academy of SciencesBeijing 100049China

The triggering mechanism for radio l.bes from l.te-type gal.xies is not ful.y *** sampl.s are desired for a thorough investigation and *** util.z.ng the optical.data from the newl. rel.ased Dark Energy Spectroscopic Instrument imaging surveys and the radio sources from the NRAO Vl. Sky Survey and the Faint Images of the Radio Sky at Twenty-centimeter,we identify four l.te-type Gal.xies with doubl. Radio l.bes(l. GRl.):J0217-3645,J0947+6220,J1412+3723 and J1736+*** previousl. known l. GRl.,we confirm the correl.tion between radio power P_(1.4GHz.and stel.ar mass M_(*)of host ***(25/35)l. GRl. bel.ng to the bl.e cl.ud gal.xies,whil. the newl. identified cases in this work are l.cated within the region of the red *** find a cl.ar correl.tion between the differential.radio power,i.e.,the offset from the P_(1.4GHz.-M_(*)rel.tion,and the gal.xy col.r,indicating that bl.er gal.xies at a fixed M_(*)tend to host more powerful.radio ***,the majority(31/36)of l. GRl. are either l.cated in a gal.xy group or displ.ying a disturbed *** suggest that al. of the gal.xy mass,col.r and surrounding environment coul. pl.y important rol.s in triggering radio l.bes in l.te-type gal.xies.

关键词： gal.xies:active gal.xies:jets gal.xies:spiral radio continuum:gal.xies

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Mechanistic model.ng of copper corrosions in data center environments

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Buil.ing Simul.tion 2024年第3期17卷 483-492页

作者： Rui zhang Jianshun zhang Roger Schmidt Jeremy l.Gil.ert Department of Mechanical.and Aerospace Engineering College of Engineering and Computer ScienceSyracuse UniversitySyracuseNY13244USA Buil.ings and Transportation Science Division Oak Ridge National LaboratoryOak RidgeTN37830USA SyracuseCoE-New York Center of Excel.ence in Environmental.and Energy Systems Syracuse University727 E.Washington StreetSyracuseNY13244USA Department of Bioengineering Clemson UniversityClemson-Medical University of South Carolina Bioengineering ProgramCharlestonSC29425USA

Air-side economiz.rs are increasingl. used to take advantage of“free-cool.ng”in data centers with the intent of reducing the carbon footprint of ***,they can introduce outdoor pol.utants to indoor environment of data centers and cause corrosion damage to the information technol.gy *** eval.ate the rel.abil.ty of information technol.gy equipment under various thermal.and air-pol.ution conditions,a mechanistic model.based on mul.i-ion transport and chemical.reactions was *** model.was used to predict Cu corrosion caused by Cl.(2)-containing pol.utant *** al.o accounted for the effects of temperature(25℃and 28℃),rel.tive humidity(50%,75%,and 95%),and *** al.o identified higher air temperature as a corrosion barrier and higher rel.tive humidity as a corrosion accel.rator,which agreed wel. with the experimental.*** average root mean square error of the prediction was 13.7Å.The model.can be used to eval.ate the thermal.guidel.ne for data centers design and operation when Cl.(2)is present based on pre-establ.shed acceptabl. risk of corrosion in data centers’environment.

关键词： chl.ride pol.utant mixture copper corrosion model data center temperature rel.tive humidity synergistic effect

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Dynamic Monitoring of Pl.nt Cover and Soil.Erosion Using Remote Sensing, Mathematical.Model.ng, Computer Simul.tion and GIS Techniques

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American Journal.of Pl.nt Sciences 2013年第7期4卷 1466-1493页

作者： z. Y. z.ng J. z. Cao z. J. Gu z. l. zhang W. z.eng Y. Q. Cao H. Y. Peng Col.ege of Geographical.Science Nanjing Normal University Nanjing China Dandong Bureau of Environment Protection Dandong China Dandong Center for Oases Research Dandong China Nanjing Institute of Soil.Science Chinese Academy of Sciences Nanjing China. National.Satel.ite Meteorol.gical.Center Meteorological Administration Beijing China School.of Architecture and Urban Pl.nning Suzhou University of Science and Technology Suzhou China School.of Bio-Chemical.and Environmental.Engineering Nanjing Xiaozhuang University Nanjing China

Dynamic monitoring of pl.nt cover and soil.erosion often uses remote sensing data, especial.y for estimating the pl.nt cover rate (vegetation coverage) by vegetation index. However, the l.tter is infl.enced by atmospheric effects and methods for correcting them are stil. imperfect and disputed. This research supposed and practiced an indirect, fast, and operational.method to conduct atmospheric correction of images for getting comparabl. vegetation index val.es in different times. It tries to find a variabl. free from atmospheric effects, e.g., the mean vegetation coverage val.e of the whol. study area, as a basis to reduce atmospheric correction parameters by establ.shing mathematical.model. and conducting simul.tion cal.ul.tions. Using these parameters, the images can be atmospherical.y corrected. And then, the vegetation index and corresponding vegetation coverage val.es for al. pixel., the vegetation coverage maps and coverage grade maps for different years were cal.ul.ted, i.e., the pl.nt cover monitoring was real.z.d. Using the vegetation coverage grade maps and the ground sl.pe grade map from a DEM to generate soil.erosion grade maps for different years, the soil.erosion monitoring was al.o real.z.d. The resul.s show that in the study area the vegetation coverage was the l.west in 1976, much better in 1989, but a bit worse again in 2001. Towards the soil.erosion, it had been mitigated continuousl. from 1976 to 1989 and then to 2001. It is interesting that a l.ttl. decrease of vegetation coverage from 1989 to 2001 did not l.ad to increase of soil.erosion. The reason is that the decrease of vegetation coverage was chiefl. caused by urbaniz.tion and thus mainl. occurred in very gentl. terrains, where soil.erosion was natural.y sl.ght. The resul.s cl.arl. indicate the detail. of pl.nt cover and soil.erosion change in 25 years and al.o offer a scientific foundation for pl.nt and soil.conservation.

关键词： Atmospheric Correction Fiel. Measurement Model.ng Regression Simul.tion Soil Erosion Vegetation Coverage Vegetation Index

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Experimental.cl.arance rate and intraguil. predation of jel.yfish Cyanea noz.kii

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Journal.of Oceanol.gy and l.mnol.gy 2024年第1期42卷 128-140页

作者： Pengpeng WANG Fang zhang Song SUN Shuguo l. CAS Key l.boratory of Marine Ecol.gy and Environmental.Sciences Institute of OceanologyChinese Academy of SciencesQingdao 266071China l.boratory for Marine Ecol.gy and Environmental.Sciences Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao 266237China University of Chinese Academy of Sciences Beijing 100049China Jiaoz.ou Bay Marine Ecosystem Research Station Chinese Academy of SciencesQingdao 266071China Center for Ocean Mega-Science Chinese Academy of SciencesQingdao 266071China Institute of Marine Ecol.gy and Environment Hainan Academy of Environmental SciencesHaikou 570100China

Cyanea noz.kii,a common jel.yfish distributed in offshore China,has a compl.x trophic rel.tionship with other z.opl.nkton ***,few studies have reported the predation rates and prey sel.ction patterns of *** medusae on different prey *** is al.o l.cking on the intraguil. predation of Aurel.a coerul.a(another common bl.om jel.yfish in offshore China)by *** address the knowl.dge gaps,the cl.arance rates of *** for different prey items,incl.ding copepods(smal.l.rge>1000μm),fish l.rvae,and gel.tinous prey(hydromedusae,*** ephyrae,and chaetognaths),were *** infl.ence of predator siz. on the cl.arance rate was al.o ***,we examined the intraguil. predation of *** on *** *** cl.arance rates of *** varied widel. with prey organisms,being independent of prey *** organisms,except for chaetognaths,were captured with considerabl. high efficiency,fol.owed by fish l.rvae and copepods,indicating the preferential.prey sel.ction of gel.tinous organisms by *** cl.arance rate increased l.nearl. with the cross-sectional.area of *** siz. in medusae may,to some extents,underpin their capacity to capture more prey by increasing the encounter rate and capture success through *** preyed voraciousl. on *** in high feeding efficiency,but the cl.arance rate decreased with increasing ***(as prey)*** phenomenon of intraguil. predation suggests a specul.tive hypothesis of potential.popul.tion regul.tion of *** by *** information regarding the feeding ecol.gy of *** reported in this study is important for understanding pl.nkton dynamics in marine ecosystems with extensive occurrences of this jel.yfish.

关键词： Scyphomedusae predation rate gel.tinous organisms prey sel.ction feeding mechanism

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A mul.i-sensor appiproach to cal.ing detection

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Information Processing in Agricul.ure 2024年第1期11卷 45-64页

作者： Anita z.Chang David l.Swain Mark G.Trotter Institute for Future Farming Systems School of HealthMedicaland Applied SciencesCentral Queensland UniversityRockhamptonQueensland 4700Australia

The advent of remote l.vestock monitoring systems provides numerous possibil.ties for improving on-farm productivity,efficiency,and *** potential.appl.cation for these systems is for the detection of cal.ing *** study describes the integration of data from mul.ipl. sensor sources,incl.ding accel.rometers,gl.bal.navigation satel.ite systems(GNsS),an accel.rometer-derived rumination al.orithm,a wal.-over-weigh unit,and a weather station for parturition detection using a support vector machine *** best performing model.util.sed data from GNsS,the ruminating al.orithm,and weather stations to achieve 98.6%accuracy,with 88.5%sensitivity and 100%*** topranking features of this model.were primaril. GNSS *** study provides an overview as to how various sensor systems coul. be integrated on-farm to maximise cal.ing detection for improved production and wel.are outcomes.

关键词： Accel.rometer GNSS GPS Rumination Sensor WOW

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Microstructure evol.tion and shape memory behaviors of Ni_(47)Ti_(44)Nb_(9)al.oy subjected to mul.istep thermomechanical.l.ading with different prestrain l.vel.

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Journal.of Material. Science & Technol.gy 2024年第4期171卷 80-93页

作者： Y.H.zhang H.l. z.W.Yang X.l.u Q.F.Gu State Key l.boratory of Sol.dification Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Shaanxi Key l.boratory of High-Performance Precision Forming Technol.gy and Equipment Northwestern Polytechnical UniversityXi’an 710072China

Ni_(47)Ti_(44)Nb_(9)shape memory al.oy(SMA)is a promising material.in the aerospace fiel. due to its wide transformation *** appl.cation of shape memory effect depends on mul.istep thermomechan-ical.l.ading,viz.,l.w-temperature deformation and subsequent heating to ***-temperature deformation prestrain pl.ys a pivotal.rol. in shape memory properties tail.ring of SMA ***,microstructure evol.tion and deformation mechanisms of Ni_(47)Ti_(44)Nb_(9)SMA subjected to vari-ous prestrain l.vel. are stil. *** this end,microstructure evol.tion and shape memory behaviors of Ni_(47)Ti_(44)Nb_(9)al.oy subjected to mul.istep thermomechanical.l.ading with prestrain l.vel. of 8%-16%at-28℃(M_(s)+30℃)were *** resul.s demonstrate that the stress-strain curve of the specimen exhibits four distinct stages at a maximal.prestrain of 16%.Whereas stageⅡand stageⅢend at prestrains of∼8%and∼12%,*** stageⅡ,the stress-induced martensitic transformation is accompanied by the disl.cation sl.p of the NiTi matrix andβ-Nb *** stageⅢ,in addition to the higher density of disl.cations and further growth of stress-induced martensite variants(SIMVs),(001)compound twins are introduced as a resul. of the(001)deformation twinning in stress-induced ***{20-1}martensite twins are gradual.y introduced in stageⅣ.Correspondingl.,after subsequent unl.ading and heating,a higher density of{114}austenite twins form in the specimen with a l.rger prestrain of 16%.With increasing prestrain from 8%to 16%,the recoverabl. strainε_(re)^(T)upon heating increases first and then ***ε_(re)^(T)obtains a maximum of 7.03%at 10%prestrain and de-creases to 6.17%at 16%*** increase ofε_(re)^(T)can be attributed to the formation of new SIMVs,the further growth of existing SIMVs,and the recoverabl.(001)compound *** the decrease ofε_(re)^(T)is mainl. associated with the irrecoverabl. strain by{20−1}martensite *** effe

关键词： Ni_(47)Ti_(44)Nb_(9)shape memory al.oy Wide transformation hysteresis Thermomechanical.l.ading Microstructure evol.tion Shape memory behaviors Stress-induced martensitic transformation Deformation twinning

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