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High-order time-reversal symmetry breaking normal state

Science China(Physics,Mechanics & Astronomy) 2024年第3期67卷 136-148页

作者： Meng Zeng Lun-Hui Hu Hong-Ye Hu Yi-Zhuang You Congjun wu Department of Physics University of CaliforniaSan DiegoCalifornia 92093USA Department of Physics Zhejiang UniversityHangzhou 310058China New Cornerstone Science Laboratory Department of PhysicsSchoolof ScienceWestlake UniversityHangzhou 30024China institute for Theoretical Sciences Westlake UniversityHangzhou 310024China Key Laboratory for Quantum Materials of Zhejiang Province School of ScienceWestlake UniversityHangzhou 310024China institute of Natural Sciences Westlake Institute for Advanced StudyHangzhou 310024China

Spontaneous time-reversal symmetry breaking plays an important role in studying strongly correlated unconventional *** two superconducting gap functions with different symmetries compete,the relative phase channel(θ_(-)≡θ_(1)-θ_(2))exhibits an ising-type Z_(2) symmetry due to the second order Josephson coupling,where θ_(1,2) are the phases of two gap *** contrast,the U(1) symmetry in the channel of θ_(+)≡(θ_(1)+θ_(2))/2 is *** phase locking,i.e.,ordering of θ_(-),can take place in the phase fluctuation regime before the onset of superconductivity,i.e.,when θ_(+) is *** θ_(-) is pinned at ±π/2,then timereversal symmetry is broken in the normal state,otherwise,if θ_(-)=0,or,π,rotational symmetry is broken,leading to a nematic normal *** both cases,the order parameters possess a 4-fermion structure beyond the scope of mean-field theory,which can be viewed as a high order symmetry *** employ an effective two-component XY-model assisted by a renormalization group analysis to address this *** a natural by-product,we also find the other interesting intermediate phase corresponds to ordering of θ_+ but with θ_(-)*** is the quartetting,or,charge-4e,superconductivity,which occurs above the low temperature Z_(2)-breaking charge-2e superconducting *** results provide useful guidance for studying novel symmetry breaking phases in strongly correlated superconductors.

关键词： superconductivity strong correlation time-reversal breaking charge-4e

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Predicting moisture condensation risk on the radiant cooling floor of an office using integration of a genetic algorithm-back-propagation neural network with sensitivity analysis

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energy and Built environment 2024年第1期5卷 110-129页

作者： Meng Su Jiying Liu Moon Keun Kim Xiaozhou wu School of Thermal engineering Shandong Jianzhu UniversityJinan 250101China Department of Civil engineering and energy Technology Oslo Metropolitan UniversityOslo N-0130Norway School of Civil engineering Dalian University of TechnologyDalianChina

Pre-dehumidification time(τ_(pre))and pre-dehumidification energy consumption(e_(pre))play important roles in preventing the condensation of moisture on the floors of rooms that use a radiant floor cooling(RFC)***,there are few theoretical or experimental studies that focus on these two important *** this study,an artificial neural network(ANN)was used to predict condensation risk for the integration of RFC systems with mixed ventilation(MV),stratum ventilation(SV),and displacement ventilation(DV)systems.A genetic algorithm-back-propagation(GA-BP)neural network model was established to predict τ_(pre) and e_(pre).Both training data and validation data were obtained from tests in a computational fluid dynamics(CFD)*** results show that the established GA-BP model can predict τ_(pre) and e_(pre) *** coefficient of determination(R^(2))of τ_(pre) and of e_(pre) were,respectively,0.973 and *** an RFC system integrated with an MV,SV,or DV system,the lowest values of τ_(pre) and e_(pre) were with the DV system,23.1 s and 0.237 kWh,respectively,for a 67.5 m^(3) ***,the best pre-dehumidification effect was with integration of the DV and RFC *** study showed that an ANN-based method can be used for predictive control for condensation prevention in RFC *** also provides a novel and effective method by which to assess the pre-dehumidification control of radiant floor surfaces.

关键词： Condensation prevention Radiant floor cooling Ventilation system genetic algorithm BP neural network

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explainable-Ai-based two-stage solution for WSN object localization using zero-touch mobile transceivers

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Science China(information Sciences) 2024年第7期67卷 27-45页

作者： Kai FANG Junxin CHeN Han ZHU Thippa Reddy GadeKALLU Xiaoping wu Wei WANG School of Mathematics and Computer Science Zhejiang A&F University School of Software Dalian University of Technology Faculty of Applied Sciences Macao Polytechnic University Department of electrical and Computer engineering Lebanese American University School of information engineering Huzhou University Guangdong-Hong Kong-Macao Joint Laboratory for emotional intelligence and Pervasive Computing Artificial Intelligence Research Institute Shenzhen MSU-BIT University

Artificial intelligence technology is widely used in the field of wireless sensor networks(WSN).Due to its inexplicability, the interference factors in the process of WSN object localization cannot be effectively eliminated. in this paper, an explainable-Ai-based two-stage solution is proposed for WSN object localization. in this solution, mobile transceivers are used to enlarge the positioning range and eliminate the blind area for object localization. The motion parameters of transceivers are considered to be.unavailable,and the localization problem is highly nonlinear with respect to the.unknown parameters. To address this,an explainable Ai model is proposed to solve the localization problem. Since the relationship among the variables is difficult to fully include in the first-stage traditional model, we develop a two-stage explainable Ai solution for this localization problem. The two-stage solution is actually a comprehensive consideration of the relationship between variables. The solution can continue to use the constraints unused in the firststage during the second-stage, thereby improving the performance of the solution. Therefore, the two-stage solution has stronger robustness compared to the closed-form solution. experimental results show that the performance of both the two-stage solution and the traditional solution will be affected by numerical changes in unknown parameters. However, the two-stage solution performs better than the traditional solution, especially with a small number of mobile transceivers and sensors or in the presence of high noise. Furthermore,we have also verified the feasibility of the proposed explainable-Ai-based two-stage solution.

关键词： explainable Ai object localization semidefinite relaxation mobile transceiver two-stage solution closed-form solution

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Numerical modeling and experimental investigation of a two-phase sink vortex and its fluid-solid vibration characteristics

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Journal of Zhejiang university-Science A(Applied Physics & engineering) 2024年第1期25卷 47-62页

作者： Zichao YiN Yesha Ni Lin Li Tong WANG Jiafeng wu Zhe Li Dapeng TAN College of Mechanical engineering Zhejiang University of TechnologyHangzhou310014China State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou310058China

A sink vortex is a common physical phenomenon in continuous casting,chemical extraction,water conservancy,and other industrial processes,and often causes damage and loss in ***,the real-time monitoring of the sink vortex state is important for improving industrial production ***,its suction-extraction phenomenon and shock vibration characteristics in the course of its formation are complex mechanical dynamic factors for flow field state *** address this issue,we set up a multi-physics model using the level set method(LSM)for a free sink vortex to study the two-phase interaction ***,a fluid–solid coupling dynamic model was deduced to investigate the shock vibration characteristics and reveal the transition mechanism of the critical flow *** numerical results show that the coupling energy shock induces a pressure oscillation phenomenon,which appears to be a transient enhancement of vibration at the vortex penetration *** central part of the transient enhancement signal is a high-frequency *** on the dynamic coupling model,an experimental observation platform was established to verify the accuracy of the numerical *** water-model experiment results were accordant with the numerical *** above results provide a reference for fluid state recognition and active vortex control for industrial monitoring systems,such as those in aerospace pipe transport,hydropower generation,and microfluidic devices.

关键词： Free sink vortex Fluid-solid coupling Level set method(LSM) Multi-physics model Vibration characteristics

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Physiological,transcriptome and gene functional analysis provide novel sights into cadmium accumulation and tolerance mechanisms in kenaf

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Journal of environmental Sciences 2024年第3期137卷 500-514页

作者： Shan Cao Meng Wang Jiao Pan Dengjie Luo Samavia Mubeen Caijin Wang Jiao Yue Xia wu Qijing wu Hui Zhang Canni Chen Muzammal Rehman Sichen Xie Ru Li Peng Chen Guangxi Key Laboratory of Agro-environment and Agric-products safety Key Laboratory of Plant Genetics and BreedingCollege of AgricultureGuangxi UniversityNanning 530004China State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources College of Life Science and TechnologyGuangxi UniversityNanning 530004China

Kenaf is considered to have great potential for remediation of heavy metals in ***,studies on molecular mechanisms of root Cd accumulation and tolerance are still *** this study,two differently tolerant kenaf cultivars were selected as materials and the physiological and transcriptomic effects were evaluated under Cd *** study showed that 200μmol/L CdCl_(2) treatment triggered the reactive oxygen species(ROS)explosion and membrane lipid *** with the Cd-sensitive cultivar‘Z',the Cd-tolerant cultivar‘F'was able to resist oxidative stress in cells by producing higher antioxidant enzyme activities and increasing the contents of ascorbic acid(AsA)and glutathione(GSH).The root cell wall of‘F'exhibited higher polysaccharide contents under Cd treatment,providing more Cd-binding *** were 3,439 differentially expressed genes(DeGs)that were co-regulated by Cd treatment in two *** biosynthesis and plant hormone signal transduction pathways were significantly enriched by functional annotation *** associated with pectin,cellulose,and hemi-cellulose metabolism were involved in Cd chelation of root cell wall;V-ATPases,ABCC3 and Narmp3 could participated in vacuolar compartmentalization of Cd;PDR1 was responsible for Cd effux;the organic acid transporters contributed to the absorption of Cd in *** genes might have played key roles in kenaf Cd tolerance and Cd ***,HcZiP2 was identified to be involved in Cd uptake and transport in *** findings provide a deeper understanding of the molecular pathways underlying Cd accumulation and detoxification mechanisms in kenaf.

关键词： Kenaf Cd stress Physiological Transcriptome HcZiP2

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Scale effect removal and range migration correction for hypersonic target coherent detection

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Journal of Systems engineering and electronics 2024年第1期35卷 14-23页

作者： wu Shang Sun Zhi JiANG Xingtao ZHANG Haonan DeNG Jiangyun Li Xiaolong CUi Guolong School of information and Communication engineering University of Electronic Science and Technology of ChinaChengdu 611731China

The detection of hypersonic targets usually confronts range migration(RM)issue before coherent integration(Ci).The traditional methods aiming at correcting RM to obtain Ci mainly considers the narrow-band radar ***,with the increasing requirement of far-range detection,the time bandwidth product,which is corresponding to radar’s mean power,should be promoted in actual ***,the echo signal generates the scale effect(se)at large time bandwidth product situation,influencing the intra and inter pulse integration *** eliminate se and correct RM,this paper proposes an effective algorithm,i.e.,scaled location rotation transform(ScLRT).The ScLRT can remove se to obtain the matching pulse compression(PC)as well as correct RM to complete Ci via the location rotation transform,being implemented by seeking the actual rotation *** to the traditional coherent detection algorithms,Sc LRT can address the se problem to achieve better detection/estimation *** last,this paper gives several simulations to assess the viability of ScLRT.

关键词： hypersonic target detection coherent integration(Ci) scale effect(se)removal range migration(RM)correction scaled location rotation transform(ScLRT)

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Numerical investigation of hydro-morphodynamic characteristics of a cascading failure of landslide dams

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Journal of Mountain Science 2024年第6期21卷 1868-1885页

作者： ZHONG Qiming CHeN Lingchun Mei Shengyao SHAN Yibo wu Hao ZHAO Kunpeng Department of Geotechnical engineering Nanjing Hydraulic Research InstituteNanjing 210024China National Key Laboratory of Water Disaster Prevention Nanjing 210098China Key Laboratory of Reservoir and Dam Safety of the Ministry of Water Resources Nanjing 210029China

A cascading failure of landslide dams caused by strong earthquakes or torrential rains in mountainous river valleys can pose great threats to people’s lives,properties,and *** this study,based on the three-dimensional Reynoldsaveraged Navier-Stokes equations(RANS),the renormalization group(RNG)k-εturbulence model,suspended and bed load transport equations,and the instability discriminant formula of dam breach side slope,and the explicit finite volume method(FVM),a detailed numerical simulation model for calculating the hydro-morphodynamic characteristics of cascading dam breach process has been *** developed numerical model can simulate the breach hydrograph and the dam breach morphology evolution during the cascading failure process of landslide dams.A model test of the breaches of two cascading landslide dams has been used as the validation *** comparison of the calculated and measured results indicates that the breach hydrograph and the breach morphology evolution process of the upstream and downstream dams are generally consistent with each other,and the relative errors of the key breaching parameters,i.e.,the peak breach flow and the time to peak of each dam,are less than±5%.Further,the comparison of the breach hydrographs of the upstream and downstream dams shows that there is an amplification effect of the breach flood on the cascading landslide dam *** key parameters,i.e.,the distance between the upstream and the downstream dams,the river channel slope,and the downstream dam height,have been used to study the flood amplification *** parameter sensitivity analyses show that the peak breach flow at the downstream dam decreases with increasing distance between the upstream and the downstream dams,and the downstream dam ***,the peak breach flow at the downstream dam first increases and then decreases with steepening of the river channel *** the flood caused by the upstream dam failure flows to the

关键词： Cascading landslide dams Cascading dam failure process Detailed numerical simulation model Flood amplification effect Parameter sensitivity analyses

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improving the electrocatalytic performances of Pt-based catalysts for oxygen reduction reaction via strong interactions with single-CoN_(4)-rich carbon support

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Chinese Chemical Letters 2024年第5期35卷 265-271页

作者： Jin Long Xingqun Zheng Bin Wang Chenzhong wu Qingmei Wang Lishan Peng Guizhou university Key Laboratory of Green Chemical and Clean energy Technology Guizhou University Engineering Research Center of Efficient Utilization for Industrial WasteInstitute of Dual-carbon and New Energy Technology Innovation and Development of Guizhou ProvinceSchool of Chemistry and Chemical EngineeringGuizhou UniversityGuiyang 550025China College of Safety engineering Chongqing University of Science&TechnologyChongqing 401331China Key Laboratory of Rare earths Chinese Academy of SciencesGanjiang Innovation AcademyGanzhou 341119China

Developing platinum-group-metal(PGM)catalysts possessing strong metal-support interaction and controllable PGM size is urgent for the sluggish oxygen reduction reaction(ORR)in proton-exchange membrane fuel ***,we propose an in-situ self-assembled reduction strategy to successfully induce highly-dispersed sub-3nm platinum nanoparticles(Pt NPs)to attach on resin-derived atomic Co coordinated by N-doped carbon substrate(Pt/Co_(SA)-N-C)for *** be specific,the interfacial electron interaction effect,along with a highly robust Co_(SA)-N-C support endow the as-fabricated Pt/Co_(SA)-N-C catalyst with significantly enhanced catalytic properties,i.e.,a mass activity(MA)of 0.719 A/mgPt at 0.9 ViR-free and a reduction of 24.2%in MA after a 20,000-cycles *** functional theory(DFT)calculations demonstrate that the enhanced electron interaction between Pt and Co_(SA)-N-C support decreases the dband center of Pt,which is in favor of lowering the desorption energy of ^(*)OH on Pt/Co_(SA)-N-C surface and accelerating the formation of H_(2)O,thus enhance the instinct activity of ***,the higher binding energy between Pt and Co_(SA)-N-C compared to Pt and C indicates that the migration of Pt has been suppressed,which theoretically explains the improved durability of Pt/Co_(SA)-*** work offers an enlightenment on constructing composite Pt-based catalysts with multiple active sites.

关键词： Fuel cells Oxygen reduction reaction Platinum Single-CoN_(4)-rich carbon support Metal-substrate interaction

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impact of Polymer Matrix on Polymer Mechanochromism from excited State intramolecular Proton Transfer

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Chinese Journal of Chemistry 2024年第6期42卷 611-616页

作者： Yu wu Xin Cheng Huan Hu Shui Hu Zhimin Ma Zhiyong Ma Beijing Advanced innovation Center for Soft Matter Science and engineering Beijing State Key Laboratory of Organic-Inorganic CompositesCollege of Chemical EngineeringBeijing University of Chemical TechnologyBeijing100029 China Center of Advanced elastomer Materials College of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing100029 China College of engineering Peking UniversityBeijing100871 China

Mechanochromic polymers based on non-covalent changes have attracted much attention ***,we report the impact of inter/intramolecular hydrogen bonds on polymer mechanochromism from the excited state intramolecular proton transfer (eSiPT) ***-NH2-OH and PhMz=2A are designed and obtained by simple and high-yield synthesis,and are connected into polyurethane and poly(methyl acrylate-co-2-ethylhexyl acrylate),*** the initial state,the PhMz-NH2-OH@PU sample shows blue fluorescence from the excited enol form (e*) excitons,owing to intermolecular hydrogen bonds that interrupt the eSiPT reactions but the PhMz=2A@PMA-2-eA sample expresses cyan fluorescence belonging to the excited keto form (K*) emission,implying that the intramolecular hydrogen bonds ***,under stretching,external force can tune the emission of the PhMz=2A@PMA-2-eA sample from K* to e* *** external force can putatively still promote a bond rotation,eSiPT reactions remain equivalently interrupted in both the relaxed and stressed states in a hydrogen-bond donating *** calculation confirms the force-induced increase in dihedral angle for the transition of eSiPT-on/***,PhMz-NH2-OH@PU and PhMz=2A@PMA-2-eA showed disparate initial eSiPT states and further different responses/sensitivity to *** study reports a novel and efficient strategy for enriching mechanochromic investigation and extending the applications of eSiPT reactions.

关键词： Polymer mechanochromism excited state intramolecular proton transfer Hydrogen bonding Supramolecular chemistry elastomers

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unknown system dynamics estimator-based impedance control for lower limb exoskeleton with enhanced performance

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Control Theory and Technology 2024年第1期22卷 56-68页

作者： Wenhao Zhang Peng Song Mingying wu Qiang Li Xinmin Mo Pingxin Ji Northwest institute of Mechanical and electrical engineering Xianyang712099ShaanxiChina Xi’an exo-Smart Dynamics Technology Ltd. Xi’an712046ShaanxiChina Department of Mechanical and engineering Beijing Institute of TechnologyBeijing100081China

in this article, an unknown system dynamics estimator-based impedance control method is proposed for the lower limb exoskeleton to stimulate the tracking flexibility with the terminal target position when suffering parametric inaccuracies and unexpected disturbances. To reinforce the robust performance, via constructing the filtering operation-based dynamic relation, i.e., invariant manifold, the.unknown system dynamics estimators are employed to maintain the accurate perturbation identification in both the hip and knee subsystem. Besides, a funnel control technique is designed to govern the convergence process within a minor overshoot and a higher steady-state precision. Meanwhile, an interactive complaint result can be obtained with the aid of the impedance control, where the prescribed terminal trajectory can be adjusted into the interaction variable-based target position by the force–position mapping, revealing the dynamic influence between the impedance coefficient (stiffness and damping) and the adjusted position magnitude. A sufficient stability analysis verifies the ultimately uniformly bounded results of all the error signals, and even the angle errors can be regulated within the predefined funnel boundary in the whole convergence. Finally, some simulations are provided to demonstrate the validity and superiority including the enhanced interaction flexibility and robustness.

关键词： Trajectory tracking invariant manifold Funnel control impedance control Lower limb exoskeleton

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