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LSTM Network-Based Adaptation Approach for Dynamic Integration in Intelligent End-Edge-Cloud Systems

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Tsinghua Science and Technology 2024年第4期29卷 1219-1231页

作者： xuan Yang James A.Esquivel Graduate School Angeles University FoundationAngeles City 2009Philippinesand also with Shandong Provincial University Laboratory for Protected HorticultureWeifang University of Science and TechnologyWeifang 262700China Graduate School Angeles University FoundationAngeles City 2009Philippines

Edge computing, which migrates compute-intensive tasks to run on the storage resources of edge devices, efficiently reduces data transmission loss and protects data privacy. However, due to limited computing resources and storage capacity, edge devices fail to support real-time streaming data query and processing. To address this challenge, first, we propose a Long Short-Term Memory (LSTM) network-based adaptive approach in the intelligent end-edge-cloud system. Specifically, we maximize the Quality of Experience (QoE) of users by automatically adapting their resource requirements to the storage capacity of edge devices through an event mechanism. Second, to reduce the uncertainty and non-complete adaption of the edge device towards the user’s requirements, we use the LSTM network to analyze the storage capacity of the edge device in real time. Finally, the storage features of the edge devices are aggregated to the cloud to re-evaluate the comprehensive capability of the edge devices and ensure the fast response of the user devices during the dynamic adaptation matching process. A series of experimental results show that the proposed approach has superior performance compared with traditional centralized and matrix decomposition based approaches.

关键词： quality of experience data query end-edge-cloud Long Short-Term Memory(LSTM)networks

Synthesis and characterization of three new solid polyoxometalates based on Wells-Dawson-derived sandwich-type polyanions [Co_(4)(H_(2.O)_(2.(P_(2.W_(15)O_(56))_(2.]^(16-)

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第3期25卷 268-274页

作者： Jjijie YE xuan XU Chuande WU Department of Chemistry Zhejiang UniversityHangzhou 310058China

Three polyoxometalate-based hybrid coordination materials,[Co_(8)(H_(2.O)_(34)(pz)_(2.{Co_(4)(H_(2.O)_(2.P_(4)W_(30)O_(112.}]·16H_(2.O(compound 1),[H_(3)O]_(4)[Co_(6)(H_(2.O)_(2.)(pz)_(2.{Co_(4)(H_(2.O)_(2.P_(4)W_(30)O_(112.}]·2.H_(2.(compound 2.,and[H_(3)O]_(4)[Co_(6)(H_(2.O)_(2.){Co_(4)(H_(2.O)_(2.P_(4)W_(30)O_(112.}]·2.H_(2.O(compound 3)(pz-pyrazine),were built from the linkage of[Co_(4)(H_(2.O)_(2.(P_(2.W_(15)O_(56)_(2.]^(16-)-(abbreviated as{Co_(4)P_(4)W_(30})polyanions and pz and/or cobalt(II)*** compounds 1 and 2.consisted of the same components,their lamellar networks were quite *** inorganic lamellar network in compound 3 was constructed by connecting{Co_(4)P_(4)W_(30)}units with cobalt(I)*** work demonstrates that the coordination modes of{Co_(4)P_(4)W_(30)}are very sensitive to synthesis conditions,while the ring-belt tetrametals are easily substituted by different transition metal cations under mild reaction conditions.

关键词： Cobalt Crystal structure Cyclic voltammetry Hybrid Polyoxometalate

Modified constitutive models for Inconel 718 considering current density and temperature in electrically assisted forming process

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Chinese Journal of Aeronautics 2024年第2期37卷 524-540页

作者： xuan CUI Rui ZHAO Min WAN School of Mechanical Engineering and Automation Beihang UniversityBeijing 100191China Jiangxi Research Institute of Beihang University Jiangxi 330000China

Electrically Assisted Forming(EAF)technology has obvious advantages in material *** develop an effective constitutive model considering electrical effects,room temperature and electrically assisted quasi-static uniaxial tensile tests were conducted using ultrathin nickelbased superalloy plates with a thickness of 0.2. *** research focused on the two most widely recognized effects:the Joule thermal and the electric athermal *** mechanism of current action can be divided into two scenarios:one considering the Joule thermal effect only,and the other considering both effects *** basic constitutive models,namely the Modified-Hollomon model and the Johnson-Cook(J-C)model,were selected to be optimized through the classification of two different situations,and four optimized constitutive models were *** was found that the J-C model with simultaneous consideration of the Joule thermal effect and electric athermal effect had the best prediction effect by comparing the results of these four ***,the accuracy of the optimization model was verified by finite element simulation of the electrically assisted stretching optimization *** results show that the constitutive model can effectively predict the temperature effect caused by the Joule heat effect and the athermal effect of current on the material.

关键词： Joule heating Elastoplasticity Plastic deformation Superalloys Constitutive models

A Review on Vibration Control of Multiple Cylinders Subjected to FlowInduced Vibrations

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China Ocean Engineering 2024年第2期38卷 183-197页

作者： XU Wan-hai MA Ye-xuan State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation Tianjin UniversityTianjin 300350China Institute of Mechanics Chinese Academy of SciencesBeijing 100190China

The fatigue damage caused by flow-induced vibration(FIV)is one of the major concerns for multiple cylindrical structures in many engineering *** FIV suppression is of great importance for the security of many cylindrical *** active and passive control methods have been employed for the vibration suppression of an isolated cylinder undergoing vortex-induced vibrations(VIV).The FIV suppression methods are mainly extended to the multiple cylinders from the vibration control of the isolated *** to the mutual interference between the multiple cylinders,the FIV mechanism is more complex than the VIV mechanism,which makes a great challenge for the FIV *** efforts have been devoted to vibration suppression of multiple cylinder systems undergoing FIV over the past two *** control methods,such as helical strakes,splitter plates,control rods and flexible sheets,are not always effective,depending on many influence factors,such as the spacing ratio,the arrangement geometrical shape,the flow velocity and the parameters of the vibration control *** FIV response,hydrodynamic features and wake patterns of the multiple cylinders equipped with vibration control devices are reviewed and *** FIV suppression efficiency of the vibration control methods are analyzed and compared considering different influence *** research on the FIV suppression of multiple cylinders is suggested to provide insight for the development of FIV control methods and promote engineering applications of FIV control methods.

关键词： flow-induced vibration vibration control multiple cylinders tandem side-by-side staggered

Recent progress in carbene-catalyzed fluoroalkylation

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Science China Chemistry 2024年第8期67卷 2448-2460页

作者： Bei Zhang xuan Zhang Jian Wang Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control Collaborative Innovation Center of Atmospheric Environment and Equipment TechnologySchool of Environmental Science and EngineeringNanjing University of Information Science and TechnologyNanjing 210044China School of Pharmaceutical Sciences Tsinghua UniversityBeijing 100084China

The fluoroalkyl fragment plays a vital role in various fields such as pharmaceuticals and materials science, and has a significant impact on human life not only on the present but also in the future. The insertion of fluoroalkyl groups into the chemical skeletons can cause considerable alternations in the chemical, physical and biological properties of molecules, which has attracted numerous scientists from different fields. This review focuses on N-heterocyclic carbene(NHC)-catalyzed fluoroalkylation reactions, providing a detailed analysis and summary of the achievements in the past two decades. Many successful examples clearly indicate that NHCs can catalyze the tranformation of fluoroalkylation reagents with various electronic characteristics, whether electrophilic, nucleophilic, or radical precursors. Herein, the fluoroalkylation reactions are classified based on different catalytic modes of NHCs: Lewis base catalysis, Umploung catalysis, radical catalysis and others. Meanwhile, by refining and systematically studying the contribution of NHC catalysis in fluoroalkylation reactions, this review is expected to provide valuable insights and enlightenment for related fields.

关键词： N-heterocyclic carbene fluoroalkylation radical catalysis

Revealing the role of calcium ion intercalation of hydrated vanadium oxides for aqueous zinc-ion batteries

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Journal of Energy Chemistry 2024年第8期95卷 9-19,I0001页

作者： Tao Zhou xuan Du Guo Gao Key Laboratory for Thin Film and Micro Fabrication of the Ministry of Education School of Sensing Science and EngineeringSchool of Electronic Information and Electrical EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Exploring suitable high-capacity V_(2.O_(5)-based cathode materials is essential for the rapid advancement of aqueous zinc ion batteries(ZIBs).However,the typical problem of slow Zn^(2.)diffusion kinetics has severely limited the feasibility of such *** this work,unique hydrated vanadates(CaVO,BaVO)were obtained by intercalation of Ca^(2.)or Ba^(2.)into hydrated vanadium *** the CaVO//Zn and BaVO//Zn batteries systems,the former delivered up to a 489.8 mAh g^(-1)discharge specific capacity at 0.1 A g^(-1).Moreover,the remarkable energy density of 370.07 Wh kg^(-1)and favorable cycling stability yard outperform BaVO,pure V_(2.O_(5),and many reported cathodes of similar ionic intercalation *** addition,pseudocapacitance analysis,galvanostatic intermittent titration(GITT)tests,and Trasatti analysis revealed the high capacitance contribution and Zn^(2.)diffusion coefficient of CaVO,while an in-depth investigation based on EIS elucidated the reasons for the better electrochemical performance of ***,ex-situ XRD,XPS,and TEM tests further demonstrated the Zn^(2.)insertion/extraction and Zn-storage mechanism that occurred during the cycle in the CaVO//Zn battery *** work provides new insights into the intercalation of similar divalent cations in vanadium oxides and offers new solutions for designing cathodes for high-capacity aqueous ZIBs.

关键词： Aqueous zinc ion batteries Cathode materials Ion pre-intercalation Vanadium oxides Energy storage mechanism

Influence of ecological function protection zone on the water conservation in Gansu-Qinghai Contiguous Region of the upper Yellow River

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Journal of Mountain Science 2024年第4期21卷 1345-1357页

作者： TONG Huali CHEN Qingbo ZHANG xuan College of Geography and Environmental Science Northwest Normal UniversityLanzhou 730070China Gansu Province Land Use and Comprehensive Improvement Engineering Research Center Lanzhou 730070China

The implementation of Ecological Function Protection Zone(EFPZ)policy is significant for the ecological restoration and conservation of soil and water in the territory *** manuscript analyzed and quantified the impact of EFPZ on the regional water conservation function,based on land use data from 2.05,2.08,2.10,2.15 and 2.2.,by conducting a counterfactual simulation along with the GeoSOS-FLUS model and the InVEST *** results demonstrate that the delineation of EFPZ can significantly influence the water conservation.(1)From 2.10 to 2.2.,as the EFPZ was implemented,the water conservation in the study area was increasing year by year,with a growth rate of 0.03×10^(8) m^(3)∙a^(-1).On the other hand,the simulated water conservation capacity without the implementation of EFPZ decreased year by year,with a decrease rate of 0.01×10^(8) m^(3)∙a^(-1).(2.The EFPZ accounts for only 2.%of the total area,but the contribution rate of water conservation reaches 80%.The actual values of water conservation and average water yield per unit pixel in the EFPZ show an increasing trend both internally and externally,while the counterfactual simulation values exhibit a decreasing trend.(3)The water conservation is much higher within the EFPZ than without *** implementation of EFPZ has a significant effect on the improvement of the water conservation capacity in Maqu EFPZ and Yellow River Source *** protection effectiveness should be enhanced in Qilian Mountain EFPZ and afforestation activities need to be carefully considered in Loess Plateau EFPZ.

关键词： Water conservation function Ecological Function Protection Zone Counterfactual simulation Geo SOS-FLUS model InVEST model

Capture Efficiency Analysis in the Circular Restricted Three-body Problem

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Research in Astronomy and Astrophysics 2024年第5期24卷 198-210页

作者： Yu-xuan Miao Xi-Yun Hou Department of Astronomy and Space Science Nanjing UniversityNanjing 210023China Institute of Space Environment and Astrodynamics Nanjing UniversityNanjing 210023China Key Laboratory of Modern Astronomy and Astrophysics Ministry of EducationNanjing 210023China

Temporary capture efficiency is studied in the framework of the circular restricted three-body problem in two ***, a non-uniform distribution of test particles around the secondary's orbit is obtained by fully accounting the secondary's gravitational influence. Second, the capture efficiency is computed based on the non-uniform distribution. Several factors influencing the result are discussed. By studying the capture efficiency in the circular restricted three-body problem of different mass ratios, a power-law relation between the capture efficiency(p) and the mass ratio(μ) is established, which is given by p ≈ 0.2. × μ^(0.53), within the range of 3.0035 ×10^(-6)≤ μ ≤ 3.0034 × 10^(-5). Taking the Sun–Earth system as an example, the influence from the orbit eccentricity of the secondary on the non-uniform distribution and the capture efficiency is studied. Our studies find that the secondary's orbit eccentricity has a negative influence on the capture efficiency.

关键词： methods numerical-celestial mechanics-planets and satellites dynamical evolution and stability

Endochondral ossification of hindlimbs in embryonic development of Japanese Quail(Coturnix japonica)

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Avian Research 2024年第1期15卷 123-132页

作者： xuan Li Yuxin Zhang Hongfeng Zhao College of Life Sciences Shaanxi Normal UniversityXi’an710119China

The endochondral ossification of hindlimb is essential to a bird’s ability to stand,walk and *** hindlimb is ossified in the embryos before hatching in precocial ***,the molecular mechanisms of hindlimb ossification in birds is still ***,we tried to examine the process of hindlimb ossification and its molecular regulation by using an animal model—Japanese Quail(Coturnix japonica).We selected four critical stages(Embryo Day:E6,E8,E12.and E16) of skeletal development of embryonic quails for hindlimb skeleton staining to show the process of endochondral ossification and to examine the molecular regulation of endochondral osteogenesis by RNA-Seq *** results showed that ossification became increased with embryonic development and most hindlimb was ossified before ***-Seq analysis revealed that various signaling pathways were involved with endochondral ossification with thyroid hormone signaling and WNT signaling pathway particularly ***,the expression levels of 42.genes were continuously upregulated and 14 genes were continuously downregulated from E6 to *** present study might provide new insights into complex molecular mechanisms in regulation of endochondral ossification.

关键词： Embryos Hindlimb Ossification Precocial Transcriptomics