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Uniform decompos.tion of velocity gradient tens.r

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Journal of Hydrodynamics 2024年第1期36卷 24-34页

作者： Chenxi ma Chaoqun Liu Department of mathematics University of Texas at ArlingtonArlingtonTXUSA

In this.paper,the principal decompos.tion of the velocity gradient tens.r[∇v]is.dis.us.ed in 3 cas.s.bas.d on the dis.riminant∆:∆0 with 3 dis.inct real eigen values.and∆=0 with 1 or 2 dis.inct real eigen *** velocity ... 详细信息

In this.paper,the principal decompos.tion of the velocity gradient tens.r[∇v]is.dis.us.ed in 3 cas.s.bas.d on the dis.riminant∆:∆s.∆>0 with 3 dis.inct real eigen values.and∆=0 with 1 or 2 dis.inct real eigen *** velocity gradient tens.r can als. be clas.ified as.rotation point,which can be decompos.d into three parts.i.e.,rotation[R],s.ear[s.and s.retching/compres.ion[s.],and non-rotation point,we defined a new res.s.ance term[L],and the tens.r can be decompos.d into three parts.i.e.,res.s.ance[L],s.ear[s.and s.retching/compres.ion[s.].Example matric are als. dis.layed to demons.rate the new *** of principal decompos.tion between 3 different cas.s.and between Res.s.ance and Liutex will als. be dis.us.ed.

关键词： Velocity gradient Liutex res.s.ance fluid kinematics

Effects.of gravel on the water abs.rption characteris.ics.and hydraulic parameters.of s.ony s.il

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Journal of Arid Land 2024年第7期16卷 895-909页

作者： ma Yan WANG Youqi ma Chengfeng YUAN Cheng BAI Yiru Breeding Bas. for s.ate Key Laboratory of Land Degradation and Ecological Res.oration in Northwes. China Ningxia UniversityYinchuan 750021China s.hool of Geography and Planning Ningxia UniversityYinchuan 750021China s.hool of Ecology and Environment Ningxia UniversityYinchuan 750021China

The eas.ern foothills.of the Helan Mountains.in China are a typical mountainous.region of s.il and gravel,where gravel could affect the water movement proces. in the *** s.udy focus.d on the effects.of different gravel contents.on the water abs.rption characteris.ics.and hydraulic parameters.of s.ony *** s.ony s.il s.mples.were collected from the eas.ern foothills.of the Helan Mountains.in April 2023 and us.d as.the experimental materials.to conduct a one-dimens.onal horizontal s.il column abs.rption *** experimental groups.with gravel contents.of 0%,10%,20%,30%,40%,and 50%were es.ablis.ed to determine the s.turated hydraulic conductivity(K_(s.),s.turated water content(θ_(s.),initial water content(θ_(i)),and retention water content(θ_(r)),and explore the changes.in the wetting front depth and cumulative abs.rption volume during the abs.rption *** Philip model was.us.d to fit the s.il abs.rption proces. and determine the s.il water abs.rption *** the length of the characteris.ic wetting front depth,s.ape coefficient,empirical parameter,invers. intake s.ction and s.il water s.ction were derived from the van Genuchten ***,the hydraulic parameters.mentioned above were us.d to fit the s.il water characteris.ic curves.uns.turated hydraulic conductivity(K_(θ))and s.ecific water capacity(C(h)).The res.lts.s.owed that the wetting front depth and cumulative abs.rption volume of each treatment gradually decreas.d with increas.ng gravel *** with control check treatment with gravel content of 0%,s.il water abs.rption rates.in the treatments.with gravel contents.of 10%,20%,30%,40%,and 50%decreas.d by 11.47%,17.97%,25.24%,29.83%,and 42.45%,*** the gravel content increas.d,invers. intake s.ction gradually increas.d,and s.ape coefficient,K_(s.,θ_(s.,andθ_(r)gradually *** the s.me s.il water content,s.il water s.ction and K_(θ)gradually decreas.d with increas.ng gravel *** the s.me s.il water s

关键词： s.ony s.il gravel content water abs.rption characteris.ics hydraulic parameters one-dimens.onal horizontal s.il column abs.rption experiment van Genuchten model eas.ern foothills.of Helan Mountains

Numerical inves.igation on characteris.ics.of interfacial wave of liquid film in gas.liquid two-phas. flow us.ng OpenFOAM

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Chines. Journal of Aeronautics 2024年第2期37卷 233-248页

作者： Xiaoqi ma Yues.e WANG Jiaming TIAN s.ate Key Laboratory of Multiphas. Flow in Power Engineering Xi’an Jiaotong UniversityXi’an 710049China

Liquid film cooling as.an advanced cooling technology is.widely us.d in s.ace *** operation of liquid film along the rocket combus.ion inner wall is.crucial for thermal protection of rocket *** s.ability of liquid film is.mainly determined by the characteris.ics.of interfacial wave,which is.rarely inves.igated right *** to improve the s.ability of thin film has.become a hot *** view of this.an advanced model bas.d on the conventional Volume of Fluid(VOF)model is.adopted to inves.igate the characteris.ics.of interfacial wave in gas.liquid flow by us.ng OpenFOAM,and the mechanis. of formation and development of wave is.revealed intuitively through numerical *** effects.from gas.velocity,s.rface tens.on and dynamic vis.os.ty of liquid(three factors.on the wave are s.udied *** can be found that the gas.velocity is.critical to the formation and development of wave,and four modes.of droplets.generation are illus.rated in this.***,a gas.vortex near the gas.liquid interface can induce formation of wave eas.ly,s. changing the gas.vortex s.ate can regulate formation and development of ***’s.more,the change rules.of three factors.influencing on the interfacial wave are obtained,and the s.rface tens.on has.a negative effect on the formation and development of wave only when the s.rface tens.on coefficient is.above the critical value,whereas.the dynamic vis.os.ty has.a pos.tive effect in this.***,the maximum height and maximum s.ope angle of wave will level off as.the gas.velocity ***,the maximum s.ope angle of wave is.us.ally no more than 38°,no matter what happens.to the three factors.

关键词： Interfacial wave Gas.liquid Two-phas. flow VOF model OpenFOAM

Trans.ent Res.ons. and Ionic Dynamics.in Organic Electrochemical Trans.s.ors

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Nano-Micro Letters 2024年第11期16卷 191-223页

作者： Chao Zhao Jintao Yang Wei ma s.ate Key Laboratory for Mechanical Behavior of materials Xi’an Jiaotong UniversityXi′an 710049People’s Republic of China

The rapid development of organic electrochemical trans.s.ors.OECTs.has.us.ered in a new era in organic electronics.dis.inguis.ing its.lf through its.application in a variety of domains.from high-s.eed logic circuits.to s.ns.tive bios.ns.rs.and neuromorphic devices.like artificial s.naps.s.and organic electrochemical random-acces. *** recent s.rides.in enhancing OECT performance,driven by the demand for s.perior trans.ent res.ons. capabilities.a comprehens.ve unders.anding of the complex interplay between charge and ion trans.ort,alongs.de electron–ion interactions.as.well as.the optimization s.rategies.remains.*** review aims.to bridge this.gap by providing a s.s.ematic overview on the fundamental working principles.of OECT trans.ent res.ons.s.emphas.zing advancements.in device phys.cs.and optimization *** review the critical as.ect of trans.ent ion dynamics.in both volatile and non-volatile applications.as.well as.the impact of materials.morphology,device s.ructure s.rategies.on optimizing trans.ent *** paper not only offers.a detailed overview of the current s.ate of the art,but als. identifies.promis.ng avenues.for future res.arch,aiming to drive future performance advancements.in divers.fied applications.

关键词： Organic electrochemical trans.s.ors Trans.ent res.ons. Ion dynamics Electronic dynamics Volatility and non-volatility

Extreme precipitation detection ability of four high-res.lution precipitation product datas.ts.in hilly area:a cas. s.udy in Nepal

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Advances.in Climate Change Res.arch 2024年第3期15卷 390-405页

作者： s.nil s.bba Yao-Ming ma Wei-Qiang ma Cun-Bo Han Land-Atmos.here Interaction and its.Climatic Effects.Group State Key Laboratory of Tibetan Plateau Earth SystemEnvironment and Resources(TPESER)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China College of Earth and Planetary s.iences University of Chinese Academy of SciencesBeijing 100049China College of Atmos.heric s.ience Lanzhou UniversityLanzhou 730000China National Obs.rvation and Res.arch s.ation for Qomolongma s.ecial Atmos.heric Proces.es.and Environmental Changes Dingri 858200China Kathmandu Center of Res.arch and Education Chinese Academy of SciencesBeijing 100101China China-Pakis.an Joint Res.arch Center on Earth s.iences Chinese Academy of SciencesIslamabad 45320Pakista

Given Nepal's.vulnerability to extreme precipitation(EP),it is.imperative to conduct a comprehens.ve analys.s.to comprehend the his.orical trends.of s.ch ***,acquiring precis. precipitation data for EP remains.challenging in mountainous.countries.like Nepal owing to the s.arcity of dens.ly gauged *** limitation impedes.the dis.emination of knowledge pertaining to EP variability events.in *** current res.arch on this.topic is.deficient for two main reas.ns.1)there is.a lack of s.udies.leveraging recently releas.d high-res.lution precipitation products.to identify their EP detection capabilities.which further hinders.the us.bility of thos. products.in data-s.arce regions.like Nepal,and 2)mos. s.udies.have focus.d on the characteris.tion of EP events.in Nepal rather than their s.atial and temporal *** addres. thes. is.ues.this.s.udy evaluated the EP detection capabilities.of four high-res.lution precipitation product datas.ts.PPDs.acros. Nepal from 1985 to *** datas.ts.include the ERA5 Land reanalys.s.data,s.tellite-bas.d precipitation data(PERs.ANN_CCs.CDR and CHIRPs.V2.0)and a merged datas.t(TPHiPr).We us.d various.s.atis.ical and categorical indices.to as.es. their ability to capture the s.atial and temporal variability of EP *** annual EP events.were characteris.d by 11 indices.divided into frequency and intens.ty *** TPHiPr merged datas.t offered a robus. depiction of monthly precipitation es.imates.achieving the highes. critical s.cces. index,accuracy,probability of detection and a low fals. alarm ratio for daily precipitation detection of 0.1 mm in ***,the PERs.ANN_CCs.CDR datas.t exhibited poor *** PPDs.s.owed increas.ng trends.in EP ***,the TPHiPr datas.t s.owcas.d thos. trends.with fewer errors.and s.ronger correlations.for many frequency(R10mm,R20mm and R25mm)and intens.ty(RX1day,RX5day,PRCPTOT and R99p)*** res.lts.indicate that TPHiPr outperformed ot

关键词： Extreme precipitation Precipitation product Nepal TPHiPr ERA5 land PERs.ANN_CCs.CDR CHIRPs.V2.0

Nuance of inward rectifying potas.ium(Kir)channel dys.unctions.in neurodegenerative dis.as.s

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Neural Regeneration Res.arch 2024年第6期19卷 1195-1196页

作者： Benjamin Garland Linlin ma Griffith Ins.itute for Drug Dis.overy&s.hool of Environment and s.ience Griffith UniversityNathanBrisbaneQLDAustralia

Neurodegenerative dis.rders.are highly prevalent and divers. in *** manifes.ation largely depends.on the cell types.involved,with aberrant inflammatory epis.des.progres.ively inducing a cons.ellation of phenotypes.that are clas.ified into s.ecific dis.as.s.bas.d on their neuropathological *** two mos. prevalent neurodegenerative dis.as.s.worldwide,Alzheimer’s.dis.as.(AD)and Parkins.n’s.dis.as.(PD),for example,s.are notable s.milarities.yet they differ in terms.of the s.ecific cell types.los. within the central nervous.s.s.em(CNs..The s.gnificant and progres.ive los. of cortical and certain s.bcortical neurons.in various.regions.is.a major defining trait of *** contras.,the s.ecific los. of dopaminergic neurons.DA)within the s.bs.antial nigra pars.compacta(s.pc)is.s.fficient to caus. motor s.mptoms.as.ociated with *** devas.ating condition aris.ng from neurodegeneration within the CNs.amyotrophic lateral s.leros.s.ALs.,res.lts.in the progres.ive death of upper and lower motor *** degeneration originates.in oligodendrocytes.whos. defective myelination abilities.lead to the denervation of the anterior horn,aggravating motor neuron death.

关键词： dis.as.s degenerative degeneration

Time-incons.s.ent s.ochas.ic linear-quadratic control problem with indefinite control weight cos.s

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s.ience China mathematics 2024年第1期67卷 211-236页

作者： Qi Lü Bowen ma s.hool of mathematics Sichuan UniversityChengdu 610064China

A time-incons.s.ent linear-quadratic optimal control problem for s.ochas.ic differential equations.is.*** introduce conditions.where the control cos. weighting matrix is.pos.ibly *** s.ch conditions.we obtain a family of clos.d-loop equilibrium s.rategies.via multi-pers.n differential *** res.lt extends.Yong’s.work(2017) in the cas. of s.ochas.ic differential equations.where a unique clos.d-loop equilibrium s.rategy can be derived under s.andard conditions.namely,the control cos. weighting matrix is.uniformly pos.tive definite,and the other weighting coefficients.are pos.tive s.midefinite).

关键词： linear-quadratic optimal control problem time-incons.s.ent cos. functional generalized Riccati equation indefinite control weight cos. clos.d-loop equilibrium s.rategy

A rigorous.real-time acous.ic pos.tioning method for ocean bottom s.is.ic exploration

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s.tellite Navigation 2024年第1期5卷 168-190页

作者： Jinye ma s.ouchuan Fang Jianhu Zhao s.hool of Geodes. and Geomatics Wuhan University129 Luoyu RoadWuhan430079China Ins.itute of marine s.ience and Technology Wuhan UniversityWuhan430079China s.rveying s.rvice Center BGP Inc.CNPCZhuozhou072751HebeiChina

The conventional technique for pos.tioning s.afloor geophones.in ocean bottom s.is.ic exploration encounters.s.veral challenges.including the s.gnificant impact of outliers.on pos.tioning res.lts.underutilization of high-precis.on obs.rvations.and low efficiency in real-time data *** is.ues.inevitably affect the quality of s.is.ic exploration *** addres. thes. challenges.and enhance the accuracy of geophone pos.tioning,this.paper propos.s.a rigorous.real-time acous.ic pos.tioning method for geophones.bas.d on s.quential adjus.ment and Baarda's.outlier detection *** propos.d method compris.s.three key s.eps.grouping the original acous.ic obs.rvations.cons.ructing the intra-group acous.ic pos.tioning model,and s.nthes.zing the pos.tioning res.lts.acros. the different *** validity and practicality of this.approach are confirmed through a s.mulation experiment as.well as.the field experiment conducted in the Bohai s.a,*** res.lts.demons.rate that the propos.d method effectively eliminates.outliers.in the original obs.rvations.and maximizes.the utilization of high-quality *** to traditional acous.ic pos.tioning methods.it s.gnificantly reduces.pos.tioning errors.from meters.to decimeters.and in s.me cas.s.can achieve centimeter-level *** the s.und velocity profile in the operating s.a area is.meas.red,the method can attain the pos.erior s.andard deviation at the millimeter level and pos.tioning errors.within 10 *** the s.und velocity profile is.unknown,the method can achieve the pos.erior s.andard deviation at centimeter-level and pos.tioning errors.of approximately 20 cm.

关键词： Ocean bottom s.is.ic exploration Geophone pos.tioning Acous.ic pos.tioning method s.quential adjus.ment Outlier detection

s.liency-guided meta-hallucinator for few-s.ot learning

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s.ience China(Information s.iences. 2024年第10期67卷 189-210页

作者： Hongguang ZHANG Chun LIU Jiandong WANG Linru ma Piotr KONIUs. Philip H.s.TORR Lin YANG s.s.ems.Engineering Ins.itute Academy of Military Sciences Data61 Commonwealth Scientific and Industrial Research Organisation Aus.ralian National Univers.ty Oxford Univers.ty

Learning novel object concepts.from limited s.mples.remains.a cons.derable challenge in deep learning. The main directions.for improving the few-s.ot learning models.include(i) des.gning a s.ronger backbone,(ii) des.gning a powerful(dynamic) meta-clas.ifier, and(iii) us.ng a larger pre-training s.t obtained by generating or hallucinating additional s.mples.from the s.all s.ale datas.t. In this.paper, we focus.on item(iii) and pres.nt a novel meta-hallucination s.rategy. Pres.ntly, mos. image generators.are bas.d on a generative network(i.e., GAN) that generates.new s.mples.from the captured dis.ribution of images. However, s.ch networks.require numerous.annotated s.mples.for training. In contras., we propos. a novel s.liency-bas.d end-to-end meta-hallucinator, where a s.liency detector produces.foregrounds.and backgrounds.of s.pport images. s.ch images.are fed into a two-s.ream network to hallucinate feature s.mples.directly in the feature s.ace by mixing foreground and background feature s.mples. Then, we propos. s.veral novel mixing s.rategies.that improve the quality and divers.ty of hallucinated feature ***, as.not all s.liency maps.are meaningful or high quality, we further introduce a meta-hallucination controller that decides.which foreground feature s.mples.s.ould participate in mixing with backgrounds. To our knowledge, we are the firs. to leverage s.liency detection for few-s.ot learning. Our propos.d network achieves.s.ate-of-the-art res.lts.on publicly available few-s.ot image clas.ification and anomaly detection benchmarks. and outperforms.competing s.mple mixing s.rategies.s.ch as.the s.-called manifold Mixup.

关键词： few-s.ot learning s.liency detection object recognition anomaly detection computer vis.on