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Effects of layer interactions on instantaneous stability of finite stokes flows

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Applied Mathematics and Mechanics(English Edition) 2024年第1期45卷 69-84页

作者： chen ZHAO Zhenli cHEN c.T.MUTASA Dong LI School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China

The stability analysis of a finite stokes layer is of practical importance in flow control. In the present work, the instantaneous stability of a finite stokes layer with layer interactions is studied via a linear stability analysis of the frozen phases of the base flow. The oscillations of two plates can have different velocity amplitudes, initial phases, and frequencies. The effects of the stokes-layer interactions on the stability when two plates oscillate synchronously are analyzed. The growth rates of two most unstable modes when δ stokes-layer thickness and the half height of the channel, resp.c.ively. However, their vorticities are different. The vorticity of the most unstable mode is symmetric, while the other is asymmetric. The stokes-layer interactions have a destabilizing effect on the most unstable mode when δ ct when δ > 0.68. However, the interactions always have a stabilizing effect on the other unstable mode. It is explained that one of the two unstable modes has much higher dissipation than the other one when the stokes-layer interactions are strong. We also find that the stability of the stokes layer is closely related to the inflectional points of the base-flow velocity profile. The effects of inconsistent velocity-amplitude, initial phase, and frequency of the oscillations on the stability are analyzed. The energy of the most unstable eigenvector is mainly distributed near the plate of higher velocity amplitude or higher oscillation frequency. The effects of the initial phase difference are complicated because the base-flow velocity is extremely sensitive to the initial phase.

关键词： finite stokes layer instantaneous stability stokes-layer interaction asynchronous oscillation

Elevated brain temperature under severe heat exposure impairs cortical motor activity and executive function

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Journal of Sport and Health Science 2024年第2期13卷 233-244页

作者： Xiang Ren Tan Mary c.Stephenson Sharifah Badriyah Alhadad Kelvin W.Z.Loh Tuck Wah Soong Jason K.W.Lee Ivan c.c.Low Health and Social Sciences Singapore Institute of TechnologySingapore 138683Singapore Human potential Translational Research programme Yong Loo Lin School of MedicineNational University of SingaporeSingapore 117597Singapore centre for Translational Magnetic Resonance Research Yong Loo Lin School of MedicineNational University of SingaporeSingapore 117549Singapore Department of physiology Yong Loo Lin School of MedicineNational University of SingaporeSingapore 117593Singapore Heat Resilience and performance centre Yong Loo Lin School of MedicineNational University of SingaporeSingapore 117510Singapore N.1 Institute for Health National University of SingaporeSingapore 117456Singapore campus for Research Excellence and Technological Enterprise(cREATE) Singapore 138602Singapore

Background:Excessive heat exposure can lead to hyperthermia in humans,which impairs physical performance and disrupts cognitive *** heat is a known physiological stressor,it is unclear how severe heat stress affects brain physiology and ***:Eleven healthy participants were subjected to heat stress from prolonged exercise or warm water immersion until their rectal temperatures(T_(re))attained 39.5℃,inducing exertional or passive hyperthermia,*** a separate trial,blended ice was ingested before and during exercise as a cooling *** were compared to a control condition with seated rest(normothermic).Brain temperature(T_(br)),cerebral perfusion,and task-based brain activity were assessed using magnetic resonance imaging ***:T_(br)in motor cortex was found to be tightly regulated at rest(37.3℃±0.4℃(mean±SD))despite fluctuations in T_(re).With the development of hyperthermia,T_(br)increases and dovetails with the rising T_(re).Bilateral motor cortical activity was suppressed during high-intensity plantarflexion tasks,implying a reduced central motor drive in hyperthermic participants(T_(re)=38.5℃±0.1℃).Global gray matter perfusion and regional perfusion in sensorimotor cortex were reduced with passive *** function was poorer under a passive hyperthermic state,and this could relate to compromised visual processing as indicated by the reduced activation of left lateral-occipital ***,ingestion of blended ice before and during exercise alleviated the rise in both T_(re)and T_(bc)and mitigated heat-related neural ***:Severe heat exposure elevates T_(br),disrupts motor cortical activity and executive function,and this can lead to impairment of physical and cognitive performance.

关键词： Brain functional activity cognition Heat stress Hyperthermia Motor function

pathogenic and therapeutic role of exosomes in neurodegenerative disorders

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Neural Regeneration Research 2024年第1期19卷 75-79页

作者： christa c.Huber Hongmin Wang Division of Basic Biomedical Sciences Sanford School of MedicineUniversity of South DakotaVermillionSDUSA

Neurodegenerative disorders affect millions of people worldwide,and the prevalence of these disorders is only projected to rise as the number of people over 65 will drastically increase in the coming *** therapies exist to aid in symptomatic relief,effective treatments that can stop or reve rse the progress of each neurodegenerative disease are ***,research on the role of extracellular vesicles as disease markers and therapeutics has been intensively ***,30-150 nm in diameter,are one type of extracellular vesicles facilitating cell-to-cell *** are thought to play a role in disease propagation in a variety of neurodegenerative diseases,such as Alzheimer's disease,parkinson s disease,and amyotrophic lateral ***,the exosomes derived from the patients are an invaluable source of disease *** the other hand,exosomes,esp.c.ally those derived from stem cells,could serve as a therapeutic for these disorders,as seen by a rapid increase in clinical trials investigating the therapeutic efficacy of exosomes in different neurological *** review summarizes the pathological burden and therapeutic approach of exosomes in neurodegenerative *** also highlight how heat shock increases the yield of exosomes while still maintaining their therapeutic ***,this review concludes with outstanding questions that remain to be addressed in exosomal research.

关键词： aging Alzheimer's disease biomarker drug exosome extracellular vesicle neurodegenerative disease parkinson's disease therapy

Multi-asp.c. analysis of ureteral access sheath usage in retrograde intrarenal surgery: A RIRSearch group study

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Asian Journal of Urology 2024年第1期11卷 80-85页

作者： Oktay Özman Hacı M.Akgül cem Başataç Önder Çınar Eyüp B.Sancak cenk M.Yazıcı Bülent Önal Haluk Akpınar Gaziosmanpasa Training and Research Hospital Urology ClinicİstanbulTurkey TekirdağNamık Kemal University School of MedicineDepartment of UrologyTekirdağTurkey Group Florence Nightingale Hospitals Department of UrologyİstanbulTurkey Zonguldak Bulent Ecevit University School of MedicineDepartment of UrologyZonguldakTurkey Çanakkale Onsekiz Mart University School of MedicineDepartment of UrologyÇanakkaleTurkey İstanbul University-cerrahpaşa Cerrahpaşa Medical FacultyDepartment of UrologyİstanbulTurkey

Objective:To evaluate the effect of ureteral access sheath(UAS)use and calibration change on stone-free rate and complications of retrograde intrarenal surgery(RIRS).Methods:Data from 568 patients undergoing RIRS for kidney or upper ureteral stones were retrosp.c.ively ***,patients were compared after 1:1 propensity score matching,according to UAS usage during RIRS(UAS used[+]87 and UAS non-used[−]87 patients).Then all UAS+patients(n=481)were subdivided according to UAS calibration:9.5-11.5 Fr,10-12 Fr,11-13 Fr,and 13-15 *** outcomes of the study were the success and complications of ***:Stone-free rate of UAS+patients(86.2%)was significantly higher than UAS−patients(70.1%)after propensity score matching(p=0.01).Stone-free rate increased with higher caliber UAS(9.5-11.5 Fr:66.7%;10-12 Fr:87.0%;11-13 Fr:90.6%;13-15 Fr:100%;ppostoperative complications of UAS+patients(11.5%)were significantly lower than UAS−patients(27.6%)(p=0.01).complications(8.7%)with 9.5-11.5 Fr UAS was lower than thicker UAS(17.2%)but was not statistically significant(p=0.09).UAS usage was an independent factor predicting stone-free status or peri-and post-operative complications(odds ratio[OR]3.654,95%confidence interval[cI]1.314-10.162;OR 4.443,95%cI 1.350-14.552;OR 4.107,95%cI 1.366-12.344,resp.c.ively).conclusion:Use of UAS in RIRS may increase stone-free rates,which also increase with higher caliber *** usage may reduce complications;however,complications seemingly increase with higher UAS calibration.

关键词： Stone Retrograde intrarenal surgery Ureteral access sheath Urolithiasis Kidney

Automated Machine Learning Algorithm Using Recurrent Neural Network to perform Long-Term Time Series Forecasting

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computers, Materials & continua 2024年第3期78卷 3529-3549页

作者： Ying Su Morgan c.Wang Shuai Liu Department of Statistics and Data Science University of Central FloridaOrlandoFL32816-2370USA School of Mathematics and Statistics Beijing Technology and Business UniversityBeijing100048China

Long-term time series forecasting stands as a crucial research domain within the realm of automated machine learning(AutoML).At present,forecasting,whether rooted in machine learning or statistical learning,typ.c.lly relies on expert input and necessitates substantial manual *** manual effort spans model development,feature engineering,hyper-parameter tuning,and the intricate construction of time series *** complexity of these tasks renders complete automation unfeasible,as they inherently demand human intervention at multiple *** surmount these challenges,this article proposes leveraging Long Short-Term Memory,which is the variant of Recurrent Neural Networks,harnessing memory cells and gating mechanisms to facilitate long-term time series ***,forecasting accuracy by particular neural network and traditional models can degrade significantly,when addressing long-term time-series ***,our research demonstrates that this innovative approach outperforms the traditional Autoregressive Integrated Moving Average(ARIMA)method in forecasting long-term univariate time *** is a high-quality and competitive model in time series prediction,and yet it requires significant preprocessing *** multiple accuracy metrics,we have evaluated both ARIMA and proposed method on the simulated time-series data and real data in both short and long ***,our findings indicate its superiority over alternative network architectures,including Fully connected Neural Networks,convolutional Neural Networks,and Nonpooling convolutional Neural *** AutoML approach enables non-professional to attain highly accurate and effective time series forecasting,and can be widely applied to various domains,particularly in business and finance.

关键词： Automated machine learning autoregressive integrated moving average neural networks time series analysis

A combined experimental and DEM investigation of grain interlocking in sheared granular assemblies

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particuology 2024年第7期90卷 436-451页

作者： Rui Lu Qiang Luo Tengfei Wang David p.c.nnolly Tao Xie School of civil Engineering Southwest Jiaotong UniversityChengdu 610031China Key Laboratory of High-Speed Railway Engineering(Southwest Jiaotong University) Ministry of EducationChengdu 610031China School of civil Engineering University of LeedsLeeds LS29JTUK Department of civil Engineering McMaster UniversityHamiltonONCanada

comp.c.ed granular material,integral to geotechnical engineering,undergoes translation,rotation,and interlocking when subject to shear displacements or external *** present study focuses on the interlocking of heterogeneous granular materials,a complex behavior influenced by gradation,comp.c.ion,and varying particle geometry,and has consequently received limited attention in existing *** address this research gap,we conducted an analysis on the effect of grain interlocking on the shear resistance of granular assemblies,using a combination of laboratory testing and the discrete element method(DEM).Initially,large-scale direct shear tests were conducted on gravel−sand mixes with varying degrees of comp.c.ion and normal *** of the mixes also underwent subsequent shear reversal to explore the differences in grain interlocking between the two shearing processes on the shear *** analyzing the laboratory results,a mesoscop.c.scale investigation was performed by replicating the test using discrete element *** facilitate this,granular particle geometries were measured using 3D laser scanning based on the physical lab ***,based on these scans,discrete element R-block and ball models were utilized to construct both the coarse and fine particles within the *** vibro-comp.c.ion was employed to regulate the degree of *** results indicate that an increase in vertical pressure,coupled with a zero dilatancy angle,results in a rising stress ratio,indicative of grain *** interlocking exhibits a positive correlation with both the coarse content and the degree of comp.c.ion,and varies depending on the shear *** interlocking progresses,the shear band,induced by particle movement,expands and is associated with reduced particle rotation near the shear *** study further reveals a consistent positive correlation between interlocking and the principal orientation angle of strong normal c

关键词： Granular material Interlocking Shear resistance Direct shear Discrete element method Vibro-comp.c.ion

Hierarchical control Strategy for Load Regulation Based on Stackelberg Game Theory considering Randomness

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cSEE Journal of power and Energy Systems 2024年第3期10卷 929-941页

作者： Tingyu Jiang ping Ju c.Y.chung Yuzhong Gong college of Energy and Electrical Engineering Hohai UniversityNanjing 211100China Department of Electrical Engineering City University of Hong KongHong Kong CF624China Department of Electrical and computer Engineering University of SaskatchewanSaskatoonSK S7N 5A9Canada cSEE IEEE

Demand response has been recognized as a valuable functionality of power systems for mitigating power *** paper proposes a hierarchical control strategy among the distribution system operator(DSO),load aggregators(LAs),and thermostatically controlled loads(TcLs);the strategy includes a scheduling layer and an executive layer to provide load *** the scheduling layer,the DSO(leader)offers compensation price(cp)strategies,and the LAs(followers)respond to cp strategies with available regulation power(ARp)*** of the DSO and LAs are modeled according to their behaviors during the load regulation *** game is adopted to capture interactions among the players and leader and to obtain the optimal strategy for each participant to achieve ***,considering inevitable random factors in practice,e.g.,renewable generation and behavior of users,two different stochastic models based on sample average approximation(SAA)and parameter modification are formulated with improved scheduling *** the executive layer,distributed TcLs are triggered based on strategies determined in the scheduling layer.A self-triggering method that does not violate user privacy is presented,where TcLs receive external signals from the LA and independently determine whether to alter their operation *** simulations are performed on the modified IEEE-24 bus system to verify effectiveness of the proposed strategy.

关键词： Demand response hierarchical control load regulation self-triggering method Stackelberg game

Data-driven Static Equivalence with physics-informed Koopman Operators

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cSEE Journal of power and Energy Systems 2024年第1期10卷 432-438页

作者： Wei Lin changhong Zhao Maosheng Gao c.Y.chung Department of Electrical Engineering The Hong Kong Polytechnic UniversityHong Kong SARChina Department of Information Engineering The Chinese University of Hong KongHong Kong SARChina School of Electrical Engineering Chongqing UniversityChongqing 400044China

With deployment of measurement units,fitting static equivalent models of distribution networks(DNs)by linear regression has been recognized as an effective method in power flow analysis of a transmission *** volatility of measurements caused by variable distributed renewable energy sources makes it more difficult to accurately fit such equivalent *** tackle this challenge,this letter proposes a novel data-driven method to improve equivalency accuracy of DNs with distributed energy *** letter provides a new persp.c.ive that an equivalent model can be regarded as a mapping from internal conditions and border voltages to border power *** mapping can be established through 1)Koopman operator theory,and 2)physical features of power flow equations at the root node of a *** of the proposed method is demonstrated on the IEEE 33-bus and IEEE 136-bus test systems connected to a 661-bus utility system.

关键词： Data-driven distribution network Koopman operator theory static equivalent model

Effect of biochar on the metabolome of soybean seedlings

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Oil crop Science 2024年第1期9卷 60-68页

作者： Nathalia E.Silva Mariana G.Aguilar Osania E.Ferreira Gleicia M.paulino Jaqueline c.L.carvalho Lúcia p.S.pimenta Alan R.T.Machado programa de pos-graduaçao em ciencias Ambientais Universidade do Estado de Minas GeraisFrutalMinas Gerais38202-436Brazil Departamento de Química Universidade Federal de Minas GeraisMinas GeraisBelo Horizonte31270-901Brazil Departamento de Engenharia Aplicada e Tecnologias Ambientais Universidade do Estado de Minas GeraisJoao MonlevadeMinas Gerais35930-314Brazil Departamento de ciencias Exatas Universidade do Estado de Minas GeraisJoao MonlevadeMinas Gerais35930-314Brazil

The use of biochar can have several effects on plant germination,depending on raw material,preparation method and application ***,the molecular mechanisms that lead to those results have yet to be *** aim of this research was to improve the understanding of these mechanisms by characterizing the metabolic effects of sugarcane bagasse biochar on soybean *** types of biochars were prepared by pyrolysis at 300℃(ScB300),400℃(ScB400)and 600℃(ScB600).Then,each one was mixed into sand at 1%,3%,5%(w/w)dose,*** experiment was performed in 8 days of incubation,when the number of germinated seeds and the average radicle length were *** evaluate the metabolome,the dry biomass(DB)was subjected to extraction with a mixture of methanol-d4 and D2O(1:1 v/v).The extracts were submitted to metabolomics analysis by proton Nuclear Magnetic *** Relative Germination,Relative Average Radicle Growth and Germination Index increased in all treatments compared to *** the other hand,the DB increased in all treatments,except for ScB300,at doses of 1%and 3%w/*** metabolites(alanine,asparagine,acetic acid,citric acid,glycerol,fatty acids and sucrose)were identified and quantified in DB extracts as the most influential finding for the separation of *** together,these results strongly suggested that biochars accelerated the catabolism of triacylglycerols to sucrose and induced a slight osmotic stress.

关键词： Germination Metabolomics 1H NMR pyrolysis Sugarcane bagasse