检索结果-南通市图书馆

Near resonance vibration isolation on a levered-dual response(LEDAR)coulomb-damped system by differential preloads/offsets in linear springs

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2024年第6期45卷 1033-1050页

作者： T.i.TOLUWALOJU c.K.THEiN D.HALiM Department of Mechanical Materials and Manufacturing EngineeringUniversity of Nottingham Ningbo ChinaNingbo 315100Zhejiang ProvinceChina Nottingham Ningbo c.ina Beacons of Excellence Research and innovation institute University of Nottingham Ningbo ChinaNingbo 315048Zhejiang ProvinceChina

The levered-dual response(LEDAR)coulomb-damped system attains near resonant vibration isolation by differential preloads/offsets in linear *** takes the advantages of both the preloads/offsets in linear springs and the guiderail fric.ion for realizing different levels of vibration *** isolation capacities are investigated on the strategies with both the horizontal and vertical guiderails,with the horizontal rail only,and without *** compressive preloads generally result in the consumption of most of the initial excitation energy so as to overcome the potential *** isolation onsets at the frequency ratio of 1∓0.095 on the left-hand side(LHS)and the right-hand side(RHS)of the lever are relative to the load plate *** observed near resonant isolation thus makes the LEDAR system a candidate for the isolation of the mechanical systems about resonance while opening a path for simultaneous harvesterisolation func.ions and passive func.ions at extreme frequencies.

关键词： lever ratio coulomb damping preload tension/compression isolation band/depth offset potential

Pathogenic and therapeutic role of exosomes in neurodegenerative disorders

在线全文

学校读者我要写书评

暂无评论

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,effec.ive 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,especially those derived from stem cells,could serve as a therapeutic for these disorders,as seen by a rapid increase in c.inical 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

Automated Mac.ine Learning Algorithm Using Recurrent Neural Network to Perform Long-Term Time Series Forecasting

在线全文

学校读者我要写书评

暂无评论

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 mac.ine learning(AutoML).At present,forecasting,whether rooted in mac.ine learning or statistical learning,typically relies on expert input and necessitates substantial manual *** manual effort spans model development,feature engineering,hyper-parameter tuning,and the intricate construc.ion 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 predic.ion,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 arc.itectures,including Fully connected Neural Networks,convolutional Neural Networks,and Nonpooling convolutional Neural *** AutoML approach enables non-professional to attain highly accurate and effec.ive time series forecasting,and can be widely applied to various domains,particularly in business and finance.

关键词： Automated mac.ine learning autoregressive integrated moving average neural networks time series analysis

Decision and coordination of an E-commerce Supply chain considering Returns and Network Externalities

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 Systems Science and Systems Engineering 2024年第5期33卷 552-575页

作者： Liang Shen Fei Lin Yuyan wang Luping Ding T.c.E.cheng Dexia wang School of Public Finance and Taxation Shandong University of Finance and Economicsjinan 250014China bschool of Management Science and Engineering Shandong University of Finance and EconomicsJinan 250014China PolyU Business School The Hong Kong Polytechnic UniversityHung HomKowloonHong Kong 999077China

considering the large number of returns in online sales and the network externalities of e-platforms,we develop a decentralized model and a centralized model to explore the impacts of returns and network externalities on e-commerce supply chain(EcSc)*** show that in the decentralized model,the service level,price,market demand,and EcSc members’profits increase with the network externality ***,the service level and price increase,while the market demand and EcSc members’profits decrease with the product return *** centralized model is the optimal operating mode when it is properly *** design the“commission and return cost-sharing”contract to optimize EcSc.in which the proportion of the e-platform’s sharing of the return handling cost is exactly equal to the proportion of the system profit after *** on the decentralized model,we develop two extended models in which we endogenize the impacts of the service level and return rate on the network externality *** comparisons between the extended and decentralized models,we show that high-quality service can improve EcSc’s profitability,while a high return rate hurts its economic performance.

关键词： E-commerce supply chain coordination mechanism network externalities return products

A Sharding Scheme Based on Graph Partitioning Algorithm for Public Blockchain

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

computer Modeling in Engineering & Sciences 2024年第6期139卷 3311-3327页

作者： Shujiang Xu Ziye wang Lianhai wang Miodrag J.Mihaljevi′c Shuhui Zhang Wei Shao Qizheng wang Key Laboratory of computing Power Network and information Security Ministry of EducationShandong Computer Science CenterQilu University of Technology(Shandong Academy of Sciences)Jinan250014China Shandong Provincial Key Laboratory of computer Networks Shandong Fundamental Research Center for Computer ScienceJinan250014China Mathematical institute The Serbian Academy of Sciences and ArtsBelgrade11000Serbia

Blockchain technology,with its attributes of decentralization,immutability,and traceability,has emerged as a powerful catalyst for enhancing traditional industries in terms of optimizing business ***,transac.ion performance and scalability has become the main challenges hindering the widespread adoption of *** to its inability to meet the demands of high-frequency trading,blockchain cannot be adopted in many *** improve the transac.ion capacity,researchers have proposed some on-chain scaling technologies,including lightning networks,directed acyc.ic graph technology,state channels,and shardingmechanisms,inwhich sharding emerges as a potential scaling ***,excessive cross-shard transac.ions and uneven shard workloads prevent the sharding mechanism from ac.ieving the expected *** paper proposes a graphbased sharding scheme for public blockchain to efficiently balance the transac.ion *** crossshard transac.ions and evening-out workloads among shards,the scheme reduces transac.ion confirmation latency and enhances the transac.ion capacity of the ***,the scheme can ac.ieve a high-frequency transac.ion as well as a better blockchain *** results show that the scheme effec.ively reduces the cross-shard transac.ion ratio to a range of 35%-56%and significantly decreases the transac.ion confirmation latency to 6 s in a blockchain with no more than 25 shards.

关键词： Blockchain sharding graph partitioning algorithm

Mechanistic.insight into cr(Ⅵ)retention by Si-containing ferrihydrite

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 Environmental Sciences 2024年第5期139卷 217-225页

作者： Ying Hu Qiang Xue Honghan chen Huaming Guo Kenneth c.carroll Song wang MOE Key Laboratory of Groundwater circulation and Environmental Evolution School of Water Resources and EnvironmentChina University of Geosciences(Beijing)Beijing 100083China Beijing Key Laboratory of Water Resources and Environmental Engineering School of Water Resources and EnvironmentChina University of GeosciencesBeijing 100083China State Key Laboratory of Biogeology and Environmental Geology China University of GeosciencesBeijing 100083China Plant&Environmental Science New Mexico State UniversityNM 88003USA institute of Theoretical chemistry College of ChemistryJilin UniversityChangchun 130023China

Hexavalent chromium[cr(Ⅵ)]causes serious harm to the environment due to its high toxicity,solubility,and ***(Fh)are the main adsorbent and trapping agent of cr(Ⅵ)in soils and aquifers,and they usually coexist with silicate(Si),forming Si-containing ferrihydrite(Si-Fh)***,the mechanism of cr(Ⅵ)retention by Si-Fh mixtures is poorly *** this study,the behaviors and mechanisms of cr(Ⅵ)adsorption onto Si-Fh with different Si/Fe molar ratios was *** electron microscope,Fourier transform infrared spectroscopy,X-ray diffrac.ion,X-ray photoelectron spectroscopy,and other techniques were used to characterize Si-Fh and cr(Ⅵ)-loading of *** results show that specific surface area of Si-Fh increases gradually with increasing Si/Fe ratios,but cr(Ⅵ)adsorption on Si-Fh decreases with increasing Si/Fe *** is because with an increase in Si/Fe molar ratio,the point of zero charge of Si-Fh gradually decreases and electrostatic repulsion between Si-Fh and cr(Ⅵ)***,the complexation of cr(Ⅵ)is enhanced due to the increase in adsorbed hydroxyl(A-OH-)on Si-Fh with increasing Si/Fe molar ratio,which partly counteracts the effect of the electrostatic ***,the increase in the electrostatic repulsion has a greater impact on adsorption than the additional complexation with *** func.ional theory calculation further supports this observation,showing the increases in electron variation of bonding atoms and reac.ion energies of inner spherical complexes with the increase in Si/Fe ratio.

关键词： Hexavalent chromium Ferrihydrite Si/Fe ratio cr(Ⅵ)Adsorption

Progress on the antiferromagnetic topological insulator MnBi2Te4

在线全文

学校读者我要写书评

暂无评论

National Science Review 2024年第2期11卷 33-49页

作者： Shuai Li Tianyu Liu chang Liu Yayu wang Hai-Zhou Lu X.c.Xie Department of Physics Harbin Institute of Technology Shenzhen institute for Quantum Science and Engineering and Department of Physics Southern University of Science and Technology(SUSTech) Quantum Science center of Guangdong-Hong Kong-Macao Greater Bay Area(Guangdong) Shenzhen Key Laboratory of Quantum Science and Engineering international Quantum Academy Beijing Academy of Quantum information Sciences Beijing Key Laboratory of Optoelectronic Func.ional Materials&Micro-Nano Devices Department of Physics Renmin University of China State Key Laboratory of Low Dimensional Quantum Physics Department of PhysicsTsinghua University Frontier Science center for Quantum information Hefei National Laboratory international center for Quantum Materials School of Physics Peking University institute for Nanoelectronic Devices and Quantum computing Fudan University

Topological materials, which feature robust surface and/or edge states, have now been a research focus in condensed maTher physics. They represent a new class of materials exhibiting nontrivial topological phases,and provide a platform for exploring exotic transport phenomena, such as the quantum anomalous Hall effect and the quantum spin Hall effect. Recently, magnetic topological materials have attracted considerable interests due to the possibility to study the interplay between topological and magnetic *** particular, the quantum anomalous Hall and axion insulator phases can be realized in topological insulators with magnetic order. MnBi2Te4, as the first intrinsic antiferromagnetic topological insulator discovered, allows the examination of existing theoretical predic.ions; it has been extensively studied, and many new discoveries have been made. Here we review the progress made on MnBi2Te4from both experimental and theoretical aspects. The bulk crystal and magnetic structures are surveyed first, followed by a review of theoretical calculations and experimental probes on the band structure and surface states, and a discussion of various exotic phases that can be realized in MnBi2Te4. The properties of MnBi2Te4thin films and the corresponding transport studies are then reviewed, with an emphasis on the edge state transport. Possible future research direc.ions in this field are also discussed.

关键词： MnBi2Te4 magnetic topological insulator antiferromagnetic quantum anomalous Hall effect axion insulator

investigations of nuclear c.irality at iThemba LABS

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Frontiers of physics 2024年第2期19卷 7-38页

作者： R.A.Bark E.A.Lawrie c.Liu S.Y.wang iThemba Laboratory for Accelerator Based Sciences National Research FoundationP.O.Box 722Somerset-West 7129South Africa Department of Physics University of the Western CapePrivate Bag X177535BellvilleSouth Africa Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment Institute of Space SciencesShandong UniversityWeihai 264209China

Progress in the studies of c.irality in atomic nuclei at iThemba LABS is *** regions of c.irality,around mass 80 and 190 have been discovered using the AFRODiTE array,specifically in the nuclei^(74)As,^(78,80,82)Br,^(81)Kr,and^(193,194,198)*** phenomena have been observed,including multiple c.iral bands in the same nucleus,the coexistence of octupole correlations and nuclear c.irality,and the coexistence of pseudo spin and nuclear *** best example of c.iral degeneracy to date was found in ^(194)*** level scheme of ^(106)Ag has been revisited and interpreted in terms of two-and four-quasiparticle *** using the particle-rotor model have shown that the fingerprints of c.irality in the two-quasiparticle system only can occur in an idealised model *** systems with a higher number of quasiparticles,the calculations showed that nuclear c.irality can persist.

关键词： c.irality high-spin states particle-rotor model

Are school uniforms associated with gender inequalities in physical ac.ivity? A pooled analysis of population-level data from 135 countries/regions

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 Sport and Health Science 2024年第4期13卷 590-598页

作者： Mairead Ryan Luiza i.c.Ricardo Nicole Nathan Riikka Hofmann Esther van Sluijs Medical Research council Epidemiology Unit University of CambridgeCambridge CB20QQUK Faculty of Education University of CambridgeCambridge CB28PQUK Hunter New England Population Health WallsendNSW 2287Australia School of Medicine and Public Health College of HealthMedicine and WellbeingUniversity of NewcastleCallaghanNSW 2308Australia Hunter Medical Research institute New Lambton HeightsNSW 2305Australia National centre of implementation Science University of NewcastleCallaghanNSW 2308Australia

Purpose:it is aimed to assess whether school uniforms are associated with population-level gender inequalities in physical ac.ivity,and whether associations differ by school level,country/region income,and assessment ***:An ecological study design was *** collected data about global uniform prac.ices using an online *** searched for country/region-level estimates of school-aged youth meeting physical ac.ivity guidelines from international surveillance *** selec.ion was conducted in duplicate using a systematic process,and a random sample of all data was checked to ensure extrac.ion and pooling processes were *** calculated absolute and relative gender inequalities in physical ac.ivity for each *** regression examined associations between country/region-level uniform prac.ices(binary yes/no exposure variable) and country/region-level gender inequalities in physical ac.ivity guideline compliance(absolute and relative inequalities).We investigated moderation by school level,stratified analyses by income group,and repeated primary analyses using device-measured ***:Pooling data from 135 countries/regions(n=1,089,852),we found no association between population-level uniform prac.ices and gender inequalities in physical ac.ivity across all ages(absolute:β=-0.2;95% confidence interval(95%ci):-1.7 to 1.3,p=0.74;relative:β=0.1;95%ci:-0.1 to 0.2,p=0.51).Subgroup analysis suggested a positive association in primary school settings(absolute:β=4.3;95%ci:-0.0 to 8.6,p=0.05).Among high-income countries,absolute inequalities were significantly greater in countries/regions with uniform prac.ices(N=37) compared to those without(N=48)(9.1(SD=3.6) vs.7.8 percentage points(SD=4.3)).Repeating analyses using device-measured data(n=32,130;N=24) did not alter our primary *** initial desc.iptive statistics,we found that in countries/regions where a maj ority of schools(>50%) reportedly use uniforms,there was lower compli

关键词： School policy clothing c.ild Adolescent Accelerometer