检索结果-南通市图书馆

Science China(Physics,Mechanics & Astronomy) 2024年第4期67卷 154-160页

作者： Yin-Zou Zhao Jiao-Jiao Song Qi-Yi Wu Hao Liu Chen Zhang Bo Chen Hong-Yi Zhang Zhen-Hua Chen Yao-Bo Huang Xue-Qing Ye Ya-Hua yuan yu-xia duan Jun He Jian-Qiao Meng School of Physics Central South UniversityChangsha 410083China Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201204China

Synchrotron-based angle-resolved photoemission spectroscopy was employed to investigate the temperature evolution of the Yb 4 f spectral for surface and bulk in the Kondo lattice YbCu_(2)Si_(2).Our study quantitatively distinguishes between the surface and bulk hybridization processes,revealing that the onset temperatures for both surface and bulk hybridization processes are significantly higher than the Kondo ***,we found that the effective surface Kondo temperature is much lower than that of the *** findings offer valuable insights into the understanding of heavy fermion physics.

关键词： Kondo lattice angle-resolved photoemission spectroscopy electronic structure hybridization surface state

维普期刊数据库

Experimental observation of the significant difference between surface and bulk Kondo processes in Kondo lattice YbCuSi

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年

作者： Yin-Zou Zhao Jiao-Jiao Song Qi-Yi Wu Hao Liu Chen Zhang Bo Chen Hong-Yi Zhang Zhen-Hua Chen Yao-Bo Huang Xue-Qing Ye Ya-Hua yuan yu-xia duan Jun He Jian-Qiao Meng School of Physics Central South University Shanghai Institute of Applied Physics Chinese Academy of Sciences

Synchrotron-based angle-resolved photoemission spectroscopy was employed to investigate the temperature evolution of the Yb4 f spectral for surface and bulk in the Kondo lattice YbCu2Si2. Our study quantitatively distinguishes between the surface and bulk hybridization processes, revealing that the onset temperatures for both surface and bulk hybridization processes are significantly higher than the Kondo temperature. Additionally, we found that the effective surface Kondo temperature is much lower than that of the bulk. These findings offer valuable insights into the understanding of heavy fermion physics.

关键词：

Prediction and scheduling of multi-energy microgrid based on BiGRU self-attention mechanism and LQPSO

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Global Energy Interconnection 2024年第3期7卷 347-361页

作者： yuchen duan Peng Li Jing xia School of Automation and Intelligence Beijing Jiaotong UniversityBeijing 100044P.R.China Goldwind Science&Technology Co.Ltd. Beijing 100176P.R.China

To predict renewable energy sources such as solar power in microgrids more accurately,a hybrid power prediction method is presented in this ***,the self-attention mechanism is introduced based on a bidirectional gated recurrent neural network(BiGRU)to explore the time-series characteristics of solar power output and consider the influence of different time nodes on the prediction ***,an improved quantum particle swarm optimization(QPSO)algorithm is proposed to optimize the hyperparameters of the combined prediction *** final proposed LQPSO-BiGRU-self-attention hybrid model can predict solar power more *** addition,considering the coordinated utilization of various energy sources such as electricity,hydrogen,and renewable energy,a multi-objective optimization model that considers both economic and environmental costs was constructed.A two-stage adaptive multi-objective quantum particle swarm optimization algorithm aided by a Lévy flight,named MO-LQPSO,was proposed for the comprehensive optimal scheduling of a multi-energy microgrid *** algorithm effectively balances the global and local search capabilities and enhances the solution of complex nonlinear *** effectiveness and superiority of the proposed scheme are verified through comparative simulations.

关键词： Microgrid Bidirectional gated recurrent unit Self-attention Lévy-quantum particle swarm optimization Multi-objective optimization

维普期刊数据库

Multiplayer Reach-Avoid Differential Games in 3D Space Inspired by Harris'Hawks'Cooperative Hunting Tactics

在线全文

学校读者我要写书评

暂无评论

Research 2024年第2期2023卷 41-54页

作者： Wanying Ruan Haibin duan Yongbin Sun Wanmai yuan Jie xia State Key Laboratory of Virtual Reality Technology and Systems School of Automation Science and Electrical EngineeringBeihang UniversityBeijingChina Peng Cheng Laboratory ShenzhenChina Information Science Academy of CETC BeijingChina

This paper investigates a multiplayer reach-avoid differential game in 3-dimensional(3D)space,which involves multiple pursuers,multiple evaders,and a designated target *** evaders aim to reach the target region,while the pursuers attempt to guard the target region by capturing the *** class of research holds significant practical ***,the complexity of the problem escalates substantially with the growing number of players,rendering its solution extremely *** this paper,the multiplayer game is divided into many subgames considering the cooperation among pursuers,reducing the computational burden,and obtaining numerically tractable strategies for ***,the Apollonius sphere,a fundamental geometric tool for analyzing the 3D differential game,is formulated,and its properties are *** on this,the optimal interception point for the pursuer to capture the evader is derived and the winning conditions for the pursuer and evader are ***,based on the Apollonius sphere,the optimal state feedback strategies of players are designed,and simultaneously,the optimal one-to-one pairings are ***,the Value function of the multiplayer reach-avoid differential game is explicitly given and is proved to satisfy Hamilton-Jacobi-Isaacs(HJI)***,the matching algorithm for the case with pursuers outnumbered evaders is provided through constructing a weighted bipartite graph,and the cooperative tactics for multiple pursuers are proposed,inspired by the Harris'Hawks intelligent cooperative hunting ***,numerical simulations are conducted to illustrate the effectiveness of the theoretical results for both cases where the number of adversary players is equal and unequal between the 2 groups.

关键词： holds satisfy rendering

Transient flameout process of boron-magnesium agglomerates during combustion in oxygen-rich atmospheres

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2024年第5期88卷 290-301页

作者： Lian duan Zhixun xia yunchao Feng Binbin Chen Likun Ma Jianxin Hu College of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073China School of Mechanical Engineering and Mechanics Xiangtan UniversityXiangtan 411105China

In this study,boron–magnesium agglomerates with varying mass ratios were prepared by drying a micron-sized boron–magnesium mixed suspension,and the combustion process of these agglomerates under different oxygen-rich concentrations were investigated using a laser ignition *** test results showed that when the mass fraction of magnesium powder in boron-magnesium agglomerates exceeded a certain threshold(between 2%and 5%),flame extinction and reignition occurred after a significant reduction in the agglomerate volume during *** process is referred to as the transient flameout process,which is affected by the magnesium content of the agglomerate and the oxygen concentration in the ambient *** increase in the magnesium content or oxygen concentration makes this phenomenon more *** weakening of the flame intensity,a dark film gradually covered the particle surfaces.X-ray diffraction and elemental analyses of the cross-section and outer surface of the condensed combustion product suggested that the dark film is primarily composed of Mg-B-O ternary *** film prevents direct contact between boron and oxygen,thereby inhibiting surface and gas-phase reactions and leading to the occurrence of the transient flameout phenomenon.

关键词： Agglomerated particle Boron–magnesium fuel Boron combustion Transient flameout process Solid fuel ramjet

On Stability Discrimination of Limit Cycles for Piecewise Smooth Systems

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年第7期40卷 1785-1803页

作者： Mao An HAN xia yu ZHOU School of Mathematical Sciences Zhejiang Normal UniversityJinhua321004P.R.China

This paper is concerned with the problem of stability discrimination of limit cycles for piecewise smooth *** first establish the Poincaré map near a periodic orbit,and deduce the first order derivative of the map for general piecewise smooth systems on the ***,we obtain a sufficient condition for determining the stability of limit cycles for these systems.

关键词： Piecewise smooth system limit cycle stability

维普期刊数据库

Towards imbalanced motion:part-decoupling network for video portrait segmentation

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第7期67卷 197-210页

作者： Tianshu yu Changqun xia Jia LI State Key Laboratory of Virtual Reality Technology and Systems School of Computer Science and EngineeringBeihang University Peng Cheng Laboratory

Video portrait segmentation(VPS), aiming at segmenting prominent foreground portraits from video frames, has received much attention in recent years. However, the simplicity of existing VPS datasets leads to a limitation on extensive research of the task. In this work, we propose a new intricate large-scale multi-scene video portrait segmentation dataset MVPS consisting of 101 video clips in 7 scenario categories,in which 10843 sampled frames are finely annotated at the pixel level. The dataset has diverse scenes and complicated background environments, which is the most complex dataset in VPS to our best *** the observation of a large number of videos with portraits during dataset construction, we find that due to the joint structure of the human body, the motion of portraits is part-associated, which leads to the different parts being relatively independent in motion. That is, the motion of different parts of the portraits is imbalanced. Towards this imbalance, an intuitive and reasonable idea is that different motion states in portraits can be better exploited by decoupling the portraits into parts. To achieve this, we propose a part-decoupling network(PDNet) for VPS. Specifically, an inter-frame part-discriminated attention(IPDA)module is proposed which unsupervisedly segments portrait into parts and utilizes different attentiveness on discriminative features specified to each different part. In this way, appropriate attention can be imposed on portrait parts with imbalanced motion to extract part-discriminated correlations, so that the portraits can be segmented more accurately. Experimental results demonstrate that our method achieves leading performance with the comparison to state-of-the-art methods.

关键词： video portrait segmentation imbalanced motion unsupervised part decoupling motion correlation inter-frame attention

同方期刊数据库

A model reduction approach for discrete-time linear time-variant systems with delayed inputs

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第4期67卷 197-217页

作者： Ai-Guo WU Guang-Ren duan yu WANG Jie ZHANG School of Mechanical Engineering and Automation Harbin Institute of Technology(Shenzhen) HIT Wuhu Robot Technology Research Institute Center for Control Science and Technology Southern University of Science and Technology

A model reduction approach is presented for discrete-time linear time-variant input-delayed systems. According to this proposed approach, a dynamical variable is constructed by taking advantage of the current state and historical information of input. It is revealed that the behavior of this dynamical variable is governed by a discrete-time linear delay-free system. It is worth noting that the presented variable transformation does not require the system matrix to be invertible. Based on the reduced delay-free models,stabilizing control laws can be easily obtained for the original delayed system. For the case with a single input delay, the constructed variable is an exact prediction for the future state, and thus the stabilizing control law could be designed by replacing the future state with its prediction. Finally, three discrete-time periodic systems with delayed input are employed to illustrate how to utilize the presented model reduction approaches.

关键词： reduction approach predictor-based feedback time-varying systems delayed input periodic system

同方期刊数据库

Recent Advance in Electrocatalytic Water Splitting for Hydrogen Production by Layered Double Hydroxides

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2024年第4期40卷 577-589页

作者： xia Tian REN Qinghui YANG Jiangrong LI Zhenhua SHAO Mingfei duan Xue State Key Laboratory of Chemical Resource Engineering College of ChemistryBeijing University of Chemical TechnologyBeijing100029P.R.China Quzhou Institute for Innovation in Resource Chemical Engineering Quzhou324000P.R.China

Collecting green hydrogen(H2)from water splitting driven by renewable energy is a new competition to implement the construction of H2 energy industry and promote new economic growth for global *** common strategy to enhance the efficiency of H2 production is to reduce the potential of electrolytic cell that is the mainstream way to prepare efficient *** double hydroxides(LDHs)are one of the most active electrocatalysts with adjustable active sites in contemporary *** this review,we discuss the recent advanced progress of LDHs for hydrogen evolution reaction(HER)on cathode and oxygen evolution reaction(OER)or organic oxidation on anode and emphasize the influence of LDHs structure regulation in water electrolysis process(HER/OER)as well as the current development status of organic oxidation catalyzed by active oxygen species on ***,we propose the current challenges of LDHs in electrocatalysis and prospect their developing tendency and further application.

关键词： Layered double hydroxide Hydrogen production Hydrogen evolution reaction(HER) Oxygen evolution reaction(OER) Electrocatalytic organic oxidation

Evolution of inner wall wrinkle defects in the sinking zone of a thick-walled steel tube during radial forging

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Manufacturing 2024年第2期12卷 396-408页

作者： yu-Zhao Yang Cheng Xu Li-xia Fan School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing210094People’s Republic of China

An axial wrinkle defect was observed in the inner wall of the sinking zone of a thick-wall steel tube processed by cold radial *** can evolve into *** present study focuses on the evolution of wrinkles and the effects of process parameters on them using a three-dimensional radial forging process finite element model,radial forging experiments,and surface morphology *** results indicated that the vertical section angle of the hammer die and the size of the tube blank significantly affect the evolution of *** height-to-width ratioλwas introduced to describe the morphology of *** had an approximately linear relationship with the radius reduction in the sinking *** was a linear correlation between the growth slope ofλand the axial to circumferential strain ratio|εr/εθ|,which can predict theλunder few process *** the 30SiMn2MoVA steel,at the junction of the forging and sinking zones,the threshold ofλof the wrinkle that can evolve into a fissure is approximately 1.123.

关键词： Radial forging Inner wall Wrinkle defects Evolution Sinking zone