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Deep Reinforcement Learning-Based Task Offloading and Service Migrating Policies in Service Caching-Assisted Mobile Edge Computing

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China Communications 2024年第4期21卷 88-103页

作者： ke Hongchang Wang Hui Sun Hongbin Halvin Yang School of Computer Technology and Engineering Changchun Institute of TechnologyChangchun 130012China College of Computer Science and Engineering Changchun University of TechnologyChangchun 130012China Department of Electronic and Electrical Engineering University College LondonLondonUK

Emerging mobile edge computing(MEC)is considered a feasible solution for offloading the computation-intensive request tasks generated from mobile wireless equipment(MWE)with limited computational resources and *** to the homogeneity of request tasks from one MWE during a longterm time period,it is vital to predeploy the particular service cachings required by the request tasks at the MEC *** this paper,we model a service caching-assisted MEC framework that takes into account the constraint on the number of service cachings hosted by each edge server and the migration of request tasks from the current edge server to another edge server with service caching required by ***,we propose a multiagent deep reinforcement learning-based computation offloading and task migrating decision-making scheme(MBOMS)to minimize the long-term average weighted *** proposed MBOMS can learn the near-optimal offloading and migrating decision-making policy by centralized training and decentralized *** and comprehensive simulation results reveal that our proposed MBOMS can converge well after training and outperforms the other five baseline algorithms.

关键词： deep reinforcement learning mobile edge computing service caching service migrating

Interregional compensation for farmland protection:From the perspective of farmland allocation optimization

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Journal of Geographical Sciences 2024年第7期34卷 1437-1454页

作者： YANG Bohan SHENG Siyu SHANGGUAN Ziheng ke Xinli School of Public Administration Central China Normal UniversityWuhan430079China School of Business Hubei UniversityWuhan430000China College of Public Administration Huazhong Agricultural UniversityWuhan430070China

Interregional compensation for farmland protection(IRCFP)is a policy instrument for encouraging farmland protection through interregional fiscal transfer *** practices and studies on IRCFP have generally determined the payers and recipients of compensation based on the present distribution of farmland,and the compensation standards did not combine farmland development right value with farmland deficit and surplus,resulting in insignificant effects on farmland protection and even policy ***,in this study,we proposed an interregional compensation mechanism for farmland protection based on farmland allocation optimization by considering 31 provincial-level regions in *** results showed that(1)the determination of farmland surplus or deficit areas based on farmland allocation optimization met the regional construction land demand from the perspective of achieving food security.(2)The combination of the compensation value standard and cropland deficit and surplus had a positive effect on farmland protection.(3)Interregional compensation for farmland protection based on farmland allocation optimization can coordinate economic development,farmland protection,and ecological ***,we discussed the rationality of interregional compensation for farmland protection based on farmland allocation optimization and designed the operation mechanism of IRCFP.

关键词： interregional compensation farmland allocation optimization farmland protection land development rights China

Hydration lubrication modulated by water structure at TiO2–aqueous interfaces

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Friction 2024年第4期12卷 591-605页

作者： Pingsu MA Yuan LIU ke HAN Yu TIAN Liran MA State key Laboratory of Tribology in Advanced Equipment Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China

The nature of solid-liquid interfaces is of great significance in *** advances have been made in lubrication based on hydration ***,a detailed molecular-level understanding is still ***,we investigated water molecule behaviors at the TiO2-aqueous interfaces by the sum-frequency generation vibrational spectroscopy(SFG-VS)and atomic force microscope(AFM)to elucidate the fundamental role of solid-liquid interfaces in *** contributions of water structures and hydration effects were revealed,where water structures played the dominant role in lubrication for TiO2 surfaces of varying hydrophilicity,while hydration effects dominated with the increasing of ion *** lubrication is observed on the initial TiO2 surfaces with strongly H-bonded water molecules compared to the hydrophilic TiO2 surfaces with more disordered *** stable ordered water arrangement with strong hydrogen bonds and the shear plane occurring between the ordered water layer and subsequent water layer may play a significant role in achieving lower *** adsorbed hydrated molecules with the increasing ionic concentration perturb ordered water but lead to the enhancement of hydration effects,which is the main reason for the improved lubrication for both *** work provides more insights into the detailed molecular-level understanding of the mechanism of hydration lubrication.

关键词： hydration lubrication interfacial water structures hydration effects titanium dioxide(TiO2)

Efficient nitrite-to-ammonia electroreduction over Zr-Ni frustrated Lewis acid-base pairs

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Science China Chemistry 2024年第5期67卷 1707-1714页

作者： Ying Zhang Zhuohang Li Wenyu Du Kai Chen ke Chu School of Materials Science and Engineering Lanzhou Jiaotong UniversityLanzhou 730070China

Electrochemical NO_(2)~--to-NH_(3) conversion(NO_(2)RR) offers a green route to NH_(3) electrosynthesis, while developing efficient NO_(2)RR catalysis systems at high current densities remains a grand challenge. Herein, we report an efficient Zr-NiO catalyst with atomically dispersed Zr-dopants incorporated in NiO lattice, delivering the exceptional NO_(2)RR performance with industriallevel current density(>0.2 A cm^(-2)). In situ spectroscopic measurements and theoretical simulations reveal the construction of ZrNi frustrated Lewis acid-base pairs(FLPs) on Zr-Ni O, which can substantially increase the number of absorbed nitrite(NO_(2)~-),promote the activation and protonation of NO_(2)~- and concurrently hamper the H coverage, boosting the activity and selectivity of Zr-NiO towards the NO_(2)RR. Remarkably, Zr-NiO exhibits the exceptional performance in a flow cell with high Faradaic efficiency for NH_(3) of 94.0% and NH_(3)yield rate of 1,394.1 μmol h^(-1)cm^(-2) at an industrial-level current density of 228.2 m A cm^(-2),placing it among the best NO_(2)RR electrocatalysts for NH_(3) production.

关键词： electrochemical nitrite-to-ammonia conversion frustrated Lewis acid-base pairs(FLPs) in situ spectroscopy theoretical computations

Control of temperature dependent viscosity for manufacturing of bi-doped active fiber

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International Journal of Extreme Manufacturing 2024年第3期6卷 522-530页

作者： Rui Duan Jingfei Chen Hao ke Tianxia Wei ke Zhang Xueliang Li Xu Feng Qiuju Zheng Zhixue He Jianrong Qiu Shifeng Zhou State key Laboratory of Luminescent Materials and Devices School of Materials Science and EngineeringSouth China University of TechnologyGuangzhou 510640People’s Republic of China Guangdong Provincial key Laboratory of Fiber Laser Materials and Applied Techniques Guangdong Engineering Technology Research and Development Center of Special Optical Fiber Materials and DevicesGuangzhou 510640People’s Republic of China School of Materials Science and Engineering Qilu University of TechnologyJinanPeople’s Republic of China Peng Cheng Laboratory Shenzhen 518000People’s Republic of China College of Optical Science and Engineering State Key Laboratory of Modern Optical InstrumentationZhejiang UniversityHangzhou 310027People’s Republic of China

bi-activated photonic materials are promising for various applications in high-capacity telecommunication,tunable laser,and advanced bioimaging and *** various bi-doped material candidates have been explored,manufacturing of bi heavily doped fiber with excellent optical activity remains a long-standing ***,a novel viscosity evolutional behavior mediated strategy for manufacturing of bi-doped active fiber with high dopant solubility is *** intrinsic relation among the evolution of bi,reaction temperature and viscosity of the glass system is ***,the effective avenue to prevent the undesired deactivation of bi during fiber drawing by tuning the temperature dependent viscosity evolution is *** applying the strategy,for the first time we demonstrate the success in fabrication of heavily doped bi active ***,the principal fiber amplifier device is constructed and broadband optical signal amplification is *** findings indicate the effectiveness of the proposed temperature dependent viscosity mediated strategy for developing novel photonic active fiber,and they also demonstrate the great potential for application in the next-generation high-capacity telecommunication system.

关键词： infrared luminescence active fiber optical amplification

Day-ahead Voltage-stability-constrained Network Topology Optimization with Uncertainties

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Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 730-741页

作者： Dingli Guo Lei Wang Ticao Jiao ke Wu Wenjing Yang the School of Electrical and Electronic Engineering Shandong University of TechnologyZibo 255000China

A day-ahead voltage-stability-constrained network topology optimization(DVNTO)problem is proposed to find the day-ahead topology schemes with the minimum number of operations(including line switching and bus-bar splitting)while ensuring the sufficient hourly voltage stability margin and the engineering operation requirement of power *** AC continuation power flow and the uncertainty from both renewable energy sources and loads are incorporated into the *** proposed DVNTO problem is a stochastic,largescale,nonlinear integer programming *** solve it tractably,a tailored three-stage solution methodology,including a scenario generation and reduction stage,a dynamic period partition stage,and a topology identification stage,is ***,to address the challenges posed by uncertainties,a novel problem-specified scenario reduction process is proposed to obtain the representative ***,to obtain the minimum number of necessary operations to alter the network topologies for the next 24-hour horizon,a dynamic period partition strategy is presented to partition the hours into several periods according to the hourly voltage information based on the voltage stability ***,a topology identification stage is performed to identify the final network topology *** effectiveness and robustness of the proposed three-stage solution methodology under different loading conditions and the effectiveness of the proposed partition strategy are evaluated on the IEEE 118-bus and 3120-bus power systems.

关键词： Network topology optimization static voltage stability line switching bus-bar splitting renewable energy source

国际秩序建构路径中的共有观念:中国与美俄国际秩序观的差异分析

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太平洋学报 2024年第2期32卷 1-16页

作者：柯研毕洪业上海外国语大学上海201620

国际秩序是国际问题研究中的重要议题,自国际关系学科形成以来便备受关注。历史上每一次国际秩序的更迭都是以权力平衡为主要路径,然而权力平衡并非国际秩序建构的唯一路径,共有观念建构也是国际秩序建构的重要路径。在中美俄互动中,基... 详细信息

国际秩序是国际问题研究中的重要议题,自国际关系学科形成以来便备受关注。历史上每一次国际秩序的更迭都是以权力平衡为主要路径,然而权力平衡并非国际秩序建构的唯一路径,共有观念建构也是国际秩序建构的重要路径。在中美俄互动中,基于对国际秩序认识的不同,形成了不同的国际秩序观。较于美俄的权力平衡,人类命运共同体作为中国国际秩序观,突出强调了共有观念的作用。共有观念在国际秩序的建构过程中发挥着基础性作用,因此,包容性共有观念建构是构建人类命运共同体过程中不可忽视的重要环节。

关键词：共有观念国际秩序中美俄互动人类命运共同体国际政治社会学

Pylorus-preserving gastrectomy for early gastric cancer

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World Journal of Gastrointestinal Oncology 2024年第3期16卷 653-658页

作者： ke-Kang Sun Yong-You Wu Department of Gastrointestinal Surgery The Affiliated Kunshan Hospital to Jiangsu UniversitySuzhou 215300Jiangsu ProvinceChina Department of Gastrointestinal Surgery The Second Affiliated Hospital of Soochow UniversitySuzhou 215008Jiangsu ProvinceChina

Pylorus-preserving gastrectomy(PPG)has been widely accepted as a function-preserving gastrectomy for middle-third early gastric cancer(EGC)with a distal tumor border at least 4 cm proximal to the *** procedure essentially preserves the function of the pyloric sphincter,which requires to preserve the upper third of the stomach and a pyloric cuff at least 2.5 *** suprapyloric and infrapyloric vessels are usually preserved,as are the hepatic and pyloric branches of the vagus *** with distal gastrectomy,PPG has significant advantages in preventing dumping syndrome,body weight loss and bile reflux *** postoperative complications after PPG have reached an acceptable *** can be considered a safe,effective,and superior choice in EGC,and is expected to be extensively performed in the future.

关键词： Gastric cancer Pylorus-preserving gastrectomy Oncological safety Gastric stasis

Assessing the range of blasting-induced cracks in the surrounding rock of deeply buried tunnels based on the unified strength theory

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Journal of Central South University 2024年第7期31卷 2341-2364页

作者： LI liang CHEN Jia-jun ZHAO lian-heng HE ke-pei HU Shi-hong LI Hua-long School of Civil Engineering Central South UniversityChangsha 410075China key Laboratory of Heavy-haul Railway Engineering Structure Ministry of EducationCentral South UniversityChangsha 410075China Hunan Provincial key Laboratory for Disaster Prevention and Mitigation of Rail Transit Engineering Structure Central South UniversityChangsha 410075China

Blasting-induced cracks in the rock surrounding deeply buried tunnels can result in water gushing and rock mass collapse,posing significant safety ***,previous theoretical studies on the range of blasting-induced cracks often ignore the impact of the in-situ stress,especially that of the intermediate principal *** particle displacement−crack radius relationship was established in this paper by utilizing the blasthole cavity expansion equation,and theoretical analytical formulas of the stress−displacement relationship and the crack radius were derived with unified strength theory to accurately assess the range of cracks in deep surrounding rock under a blasting *** analysis showed that the crushing zone size was positively correlated with in-situ stress,intermediate principal stress,and detonation pressure,whereas negatively correlated with Poisson ratio and decoupling *** dilatancy angle-crushing zone size relationship exhibited nonmonotonic *** relationships in the crushing zone and the fracture zone exhibited opposite trends under the influence of only in-situ stress or intermediate principal *** the in-situ stress increased from 0 to 70 MPa,the rate of change in the crack range and the attenuation rate of the peak vibration velocity gradually slowed.

关键词： deep drilling and blasting cracks in surrounding rock unified strength theory intermediate principle stress in-situ stress cavity expansion dilatancy characteristics