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A landscape persistence-based methodological framework for assessing ecological stability

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Environmental Science and Ecotechnology 2024年第1期17卷 31-39页

作者： Da lü Yihe lü Guangyao Gao Siqi Sun Yi Wang Bojie Fu State Key laboratory of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of SciencesPO Box 2871Beijing100085China University of Chinese Academy of Sciences Beijing100049China

Ecological stability is a critical factor in global sustainable development,yet its significance has been *** we introduce a landscape-oriented framework to evaluate ecological stability in the Qingzang Plateau(QP).Our findings reveal a medium-high stability level in the QP,with minimal changes over recent *** driving factors vary across landscape types,with climate and anthropogenic factors emerging as crucial *** anthropogenic factors are strong but unstable due to policy changes and economic development,climatic factors exert a consistent *** on our results,we propose site-specific ecological conservation and restoration *** ecological stability assessment framework provides a practical tool to understand the link between environmental conditions and ecosystems.

关键词： Ecological stability assessment framework landscape changes Nature conservation and ecological restoration Nature-based solutions Qingzang Plateau

Optimal Control of Service Rates of Discrete-Time(s,Q)Queueing-Inventory Systems with Finite Buffer

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Journal of Systems Science and Systems Engineering 2024年第3期33卷 261-280页

作者： l.Iniya B.Sivakumar G.Arivarignan School of Mathematics Madurai Kamaraj UniversityMaduraiTamilnaduIndia Department of Statistics Manonmaniam Sundaranar UniversityTirunelveliTamilnaduIndia

This article,we develop an optimal policy to control the service rate of a discrete time queueing-inventory system with finite *** customers arrive according to a Bernoulli process and the service time for the customers are *** the buffer size attains its maximum,any arriving new customers are considered to be *** customers are served one by one according to FCFS rule and each customers request random number of *** inventory is replenished according to a(s,Q)inventory policy with geometric lead *** main objectives of this article are to determine the service rates to be employed at each slot so that the long run expected cost rate is minimized for fixed inventory level and fixed buffer size and to minimize the expected waiting time for a fixed inventory level and fixed buffer *** problems are modelled as Markov decision *** establish the existence of a stationary policy and employ linear programming method to find the optimal service *** provide some numerical examples to illustrate the behaviour of the model.

关键词： Queueing-inventory system discrete time batch demand-Markov decision process

A Hybrid Approach to Maximize lifetime in Connected Directional Sensor Networks with Adjustable Sensing Ranges

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Chinese Journal of Electronics 2018年第1期27卷 159-167页

作者： lIU Shufen GAO sihua HAN lu College of Computer Science and Technology Jilin University

A directional sensor network consists of numerous small sensor nodes that have limited battery power and operate within a restricted sensing range angle. Coverage and connectivity, as two important issues,are widely studied in directional sensor networks. Different from conventional directional sensor nodes in previous studies, those in the present study could adjust their sensing ranges within a range of several values. This paper addresses the Connected adjusted-ranges directional cover(CARDC) problem. The purpose is to organize the directional sensor nodes into a group of connected covers, and assign activities to them, thereby maximizing the network lifetime. We propose a hybrid approach that combines column generation with a genetic algorithm to solve the CARDC problem. The genetic algorithm is utilized to settle the auxiliary problem of column generation, which has the ability to efficiently provide attractive columns for the master problem. Compared with pure integer linear programming formulations, the proposed genetic algorithm significantly improves the speed of column generation method, especially in large-scale networks. The effect variety of number of directions, number of power levels,and communication range on the network lifetime are also investigated.

关键词： Directional sensor networks(DSNs) Coverage and connectivity Column generation Genetic algorithm

New insight into photoacoustic conversion efficiency by plasmon-mediated nanocavitation： Implications for precision theranostics

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Nano Research 2017年第8期10卷 2800-2809页

作者： Yujiao Shi sihua Yang Da Xing Ministry of Education Key laboratory of laser life Science and Institute of laser life Science College of Biophotonics South China Normal University Guangzhou 510631 China

The probe-assisted integration of imaging and therapy into a single modality offers significant advantages in bio-applications. As a newly developed photoacoustic （PA） mechanism, plasmon-mediated nanocavitation, whereby photons are effectively converted into PA shockwaves, has excellent advantages for image-guided therapy. In this study, by simulating the laser absorption, temperature field, and nanobubble dynamics using both finite-element analysis and computational fluid dynamics, we quantified the cavitation-induced PA conversion efficiency of a water-immersed gold nanosphere, revealing new insights. Interestingly, sequential multi-bubble emission accompanied by high PA signal production occur under a single high-dose pulse of laser irradiation, enabling a cavitation-induced PA conversion efficiency up to 2%, which is -50 times higher than that due to thermal expansion. The cavitation-induced PA signal has unique frequency characteristics, which may be useful for a new approach for in vivo nanoparticle tracking. Our work offers theoretical guidance for accurate diagnosis and controllable therapy based on plasmon-mediated nanocavitation.

关键词： photoacoustic imaging conversion efficiency nanocavitation theranostics

Dual Additives for Stabilizing li Deposition and SEI Formation in Anode-Free li-Metal Batteries

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Energy & Environmental Materials 2024年第3期7卷 84-92页

作者： Baolin Wu Chunguang Chen Dmitri l.Danilov Zhiqiang Chen Ming Jiang Rüdiger-A.Eichel Peter H.l.Notten Forschungszentrum Jülich(IEK-9) D-52425Jülich Germany RWTH Aachen University D-52074Aachen Germany lNM Institute of MechanicsChinese Academy of SciencesBeijing 100190China School of Engineering Sciences University of Chinese Academy of SciencesBeijing 100049China Eindhoven University of Technology P.O.Box 5135600 MBEindhoven The Netherlands School of Electronics and Information Institute of Carbon Neutrality and New EnergyHangzhou Dianzi UniversityHangzhou 310018China University of Technology Sydney BroadwaySydney NSW 2007Australia

Anode-free li-metal batteries are of significant interest to energy storage industries due to their intrinsically high ***,the accumulative li dendrites and dead li continuously consume active li during *** results in a short lifetime and low Coulombic efficiency of anode-free li-metal *** effective electrolyte additives can improve the li deposition homogeneity and solid electrolyte interphase(SEI)stability for anode-free li-metal ***,we reveal that introducing dual additives,composed of liAsF6 and fluoroethylene carbonate,into a low-cost commercial carbonate electrolyte will boost the cycle life and average Coulombic efficiency of NMC‖Cu anode-free li-metal *** NMC‖Cu anode-free li-metal batteries with the dual additives exhibit a capacity retention of about 75%after 50 cycles,much higher than those with bare electrolytes(35%).The average Coulombic efficiency of the NMC‖Cu anode-free li-metal batteries with additives can maintain 98.3%over 100 *** contrast,the average Coulombic efficiency without additives rapidly decline to 97%after only 50 *** situ Raman measurements reveal that the prepared dual additives facilitate denser and smoother li morphology during li *** dual additives significantly suppress the li dendrite growth,enabling stable SEI formation on anode and cathode *** results provide a broad view of developing low-cost and high-effective functional electrolytes for high-energy and long-life anode-free li-metal batteries.

关键词： anode-free lithium metal battery dual additives in situ Raman li growth SEI formation

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Investigation of the effects of radial clearance on the screw conveyor performances for different inclinations

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Particuology 2024年第9期92卷 72-80页

作者： Berna Bolat Birgül Aşçıoğlu Temiztaş Enes Sezer Department of Mechanical Engineering Yıldız Technical University34349BeşiktaşİstanbulTurkey

Screw conveyors are widely used for bulk material *** study investigates the critical role of radial clearance,the gap between the screw and the conveyor body,on performance across various inclination *** Discrete Element Method(DEM)is employed to analyze the effects of different radial clearances on conveyor performance for concrete aggregate and sand as bulk *** efficiencies and capacity losses serve as key performance indicators,quantitatively assessed for each radial clearance and inclination *** validation is conducted to corroborate the *** the study,the optimal radial clearance was identified as 1.5 to 3 times of the particle *** optimal clearance minimizes the material jamming and increases the performance for screw conveyors with different inclinations and bulk material types as a result.

关键词： Screw conveyors Radial clearance Discrete element method(DEM) Volumetric efficiency Conveyor performance

Mechanics and physics under supergravity conditions

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Acta Mechanica Sinica 2024年第6期40卷 1-2页

作者： Chaofeng lü Chao Sun Shengqiang Cai Faculty of Mechanical Engineering and Mechanics Ningbo UniversityNingbo 315211China New Cornerstone Science laboratory Center for Combustion EnergyDepartment of Energy and Power EngineeringTsinghua UniversityBeijing 100084China Department of Mechanical and Aerospace Engineering University of CaliforniaSan DiegoLa Jolla CA 92093USA

"Supergravity"refers to the conditions where the effective gravity is greater than that of *** conditions are generally relevant to stellar evolution,geophysical movement,astrophysical flows,and *** also frequently occur in various engineering scenarios involving acceleration,such as the launch of space shuttles,operation of rotor engines,impacts and explosions,chemical separation processes,and overloaded testing *** is already demonstrated in physiological experiments that living organisms of animals or plants could be damaged,either temporarily or permanently,when subjected to *** create supergravity conditions for scientific research on the Earth,centrifugal equipment or rapidly rotating devices are omnipresent in various fields,such as aerospace engineering,geophysical science,chemical and biomedical engineering,nuclear engineering,rotating flows,and physical modeling tests.

关键词： geophysical Earth stellar

Effect of Salty Fog on Flashover Characteristics of OCS Composite Insulators

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Chinese Journal of Electrical Engineering 2019年第3期5卷 59-66页

作者： sihua Wang Youlong Wu College of Automation&Electrical Engineering Lanzhou Jiaotong UniversityLanzhou 730070China Rail Transit Electrical Automation Engineering laboratory of Gansu Province Lanzhou Jiaotong UniversityLanzhou 730070China

To study the flashover characteristics of the fog water in saline-alkali areas for high-speed railway OSC insulators,the spatial distributions of both the potential and electric field of soiled insulators in the presence of salty fog are analyzed using COMSOl Multiphysics,a multi-physics coupling ***,to analyze the effect of the contamination of insulators due to salty fog water,a saline solution is used for staining an insulator sample by using the solid coating *** an artificial climate chamber,the salty fog environment is simulated,and the flashover voltage for different salty fog water conductivities and surface staining are *** salt-density correction coefficient K is also *** provides a strong basis for the selection of railway insulators in saline-alkali *** results show that the salty fog water changes the original surface equivalent salt density,ρESDD,by wetting the existing fouling layer on the surface of the insulator,so that the original surface contamination layer becomes equivalent to KρESDD;the smaller is the value ofρESDD of the insulator surface,the larger is the value of K;the surface of the same insulator is dirty,and as the concentration of salty fog-water increases,K also increases.

关键词： Salty fog composite insulators flashover characteristics COMSOl multiphysics additional salt density

Science and reflections: With some thoughts to young applied scientists and engineers

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Earthquake Science 2024年第5期37卷 459-493页

作者： Robert l Nowack Department of Earth Atmospheric and Planetary SciencesPurdue UniversityWest LafayetteIN47906USA

I provide some science and reflections from my experiences working in geophysics,along with connections to computational and data sciences,including recent developments in machine learning.I highlight several individuals and groups who have influenced me,both through direct collaborations as well as from ideas and insights that I have learned *** my reflections are rooted in geophysics,they should also be relevant to other computational scientific and engineering fields.I also provide some thoughts for young,applied scientists and engineers.

关键词： geophysics computational and data science applied science and engineering

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