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Influence of ground effect on flow field structure and aerodynamic noise of high-speed trains

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第2期25卷 147-160页

作者： Xiaoming tan Linli GONG Xiaohong ZHANG Zhigang yang Key Laboratory of Intelligent Manufacturing and Service Performance Optimization of Laser and Grinding in Mechanical Industry Hunan Institute of Science and TechnologyYueyang414000China Key Laboratory of Traffic Safety on Track(Central South University) Ministry of EducationSchool of Traffic&Transportation EngineeringCentral South UniversityChangsha410075China

The simulation of the ground effect has always been a technical difficulty in wind tunnel tests of high-speed trains.In this paper,large eddy simulation and the curl acoustic integral equation were used to simulate the flow-acoustic field results of high-speed trains under four ground simulation systems(GSSs):“moving ground+rotating wheel”,“stationary ground+rotating wheel”,“moving ground+stationary wheel”,and“stationary ground+stationary wheel”.By comparing the fluid-acoustic field results of the four GSSs,the influence laws of different GSSs on the flow field structure,aero-acoustic source,and far-field radiation noise characteristics were investigated,providing guidance for the acoustic wind tunnel testing of high-speed trains.The calculation results of the aerodynamic noise of a 350 km/h high-speed train show that the moving ground and rotating wheel affect mainly the aero-acoustic performance under the train bottom.The influence of the rotating wheel on the equivalent sound source power of the whole vehicle was not more than 5%,but that of the moving ground slip was more than 15%.The average influence of the rotating wheel on the sound pressure level radiated by the whole vehicle was 0.3 dBA,while that of the moving ground was 1.8 dBA.

关键词： High-speed train Aero-acoustics Flow field structure Large eddy simulation Moving ground condition Rotating wheel

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Naturally Crosslinked Biocompatible Carbonaceous Liquid Metal Aqueous Ink Printing Wearable Electronics for Multi-Sensing and Energy Harvesting

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Nano-Micro Letters 2024年第8期16卷 148-168页

作者： King Yan Chung Bingang Xu Di tan Qingjun yang Zihua Li Hong Fu Nanotechnology Center School of Fashion and TextilesThe Hong Kong Polytechnic UniversityHong Kong 999077People’s Republic of China Department of Mathematics and Information Technology The Education University of Hong KongHong KongPeople’s Republic of China

Achieving flexible electronics with comfort and durability comparable to traditional textiles is one of the ultimate pursuits of smart wearables.Ink printing is desirable for e-textile development using a simple and inexpensive process.However,fabricating high-performance atop textiles with good dispersity,stability,biocompatibility,and wearability for high-resolution,large-scale manufacturing,and practical applications has remained challenging.Here,waterbased multi-walled carbon nanotubes(MWCNTs)-decorated liquid metal(LM)inks are proposed with carbonaceous gallium–indium micro-nanostructure.With the assistance of biopolymers,the sodium alginate-encapsulated LM droplets contain high carboxyl groups which non-covalently crosslink with silk sericin-mediated MWCNTs.E-textile can be prepared subsequently via printing technique and natural waterproof triboelectric coating,enabling good flexibility,hydrophilicity,breathability,wearability,biocompatibility,conductivity,stability,and excellent versatility,without any artificial chemicals.The obtained e-textile can be used in various applications with designable patterns and circuits.Multi-sensing applications of recognizing complex human motions,breathing,phonation,and pressure distribution are demonstrated with repeatable and reliable signals.Self-powered and energy-harvesting capabilities are also presented by driving electronic devices and lighting LEDs.As proof of concept,this work provides new opportunities in a scalable and sustainable way to develop novel wearable electronics and smart clothing for future commercial applications.

关键词： Biocompatible Conductive ink Biopolymer E-textile Carbonaceous liquid metal

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Energy mechanism of bolt supporting effect to fissured rock under static and dynamic loads in deep coal mines

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International Journal of Mining Science and Technology 2024年第3期34卷 371-384页

作者： Deyuan Fan Xuesheng Liu Yunliang tan Xuebin Li Shenglong yang College of Energy and Mining Engineering Shandong University of Science and TechnologyQingdao 266590China State Key Laboratory of Mining Disaster Prevention and Control Shandong University of Science and TechnologyQingdao 266590China National Energy Group Ningxia Coal Industry Co. Ltd.Yinchuan 753001China

The stability control of fissured rock is difficult,especially under static and dynamic loads in deep coal mines.In this paper,the dynamic mechanical properties,strain rate evolution and energy dissipation of fissured and anchored rocks were respectively obtained by SHPB tests.It was found that bolt can provide supporting efficiency-improving effect for fissured rock against dynamic disturbance,and this effect increased quadratically with decrease in anchoring angles.Then,the energy dissipation mechanism of anchored rock was obtained by slipping model.Furthermore,bolt energy-absorbing mechanism by instantaneous tensile-shear deformation was expressed based on material mechanics,which was the larger the anchoring angle,the smaller the energy absorption,and the less the contribution to supporting efficiency improvement.On this basis,the functional relationship between energy dissipation of anchored rock and energy absorption of bolt was established.Taking the coal-gangue separation system of Longgu coal mine as an example,the optimal anchoring angle can be determined as 57.5°–67.5°.Field monitoring showed fissured rock with the optimal anchoring angle,can not only effectively control the deformation,but also fully exert the energy-absorbing and efficiency-improving effect of bolt itself.This study provides guidance to the stability control and supporting design for deep engineering under the same or similar conditions.

关键词： Static and dynamic loads Anchored rock Energy absorption Anchoring angle Engineering verification

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Combining reinforcement learning with mathematical programming:An approach for optimal design of heat exchanger networks

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Chinese Journal of Chemical Engineering 2024年第5期69卷 63-71页

作者： Hui tan Xiaodong Hong Zuwei Liao Jingyuan Sun Yao yang Jingdai Wang Yongrong yang State Key Laboratory of Chemical Engineering College of Chemical and Biological EngineeringZhejiang UniversityHangzhou 310027China ZJU-Hangzhou Global Scientific and Technological Innovation Center Hangzhou 311215China

Heat integration is important for energy-saving in the process industry.It is linked to the persistently challenging task of optimal design of heat exchanger networks(HEN).Due to the inherent highly nonconvex nonlinear and combinatorial nature of the HEN problem,it is not easy to find solutions of high quality for large-scale problems.The reinforcement learning(RL)method,which learns strategies through ongoing exploration and exploitation,reveals advantages in such area.However,due to the complexity of the HEN design problem,the RL method for HEN should be dedicated and designed.A hybrid strategy combining RL with mathematical programming is proposed to take better advantage of both methods.An insightful state representation of the HEN structure as well as a customized reward function is introduced.A Q-learning algorithm is applied to update the HEN structure using theε-greedy strategy.Better results are obtained from three literature cases of different scales.

关键词： Heat exchanger network Reinforcement learning Mathematical programming Process design

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Advancing mid-infrared microdisk laser emission with Tm:YAG

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Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 91-96页

作者： Zhaocong Wang Huiqi Li Lei Wang yang tan Feng Chen School of Physics State Key Laboratory of Crystal MaterialsShandong UniversityJinan 250100China

Mid-infrared microcavity lasers have important applications in biosensing,mid-infrared spectroscopy,and environmental monitoring.However,the low output power of existing mid-infrared microcavity lasers hinders their practical use.This drawback is attributed to the insufficient laser gain medium,which limits the development of mid-infrared whispering-gallerymode(WGM)lasers.To address this issue,we have employed ion implantation-enhanced etching to fabricate Tm:YAG thin films as effective gain media for mid-infrared WGM lasers.The Tm:YAG thin film,with a thickness of 2μm,exhibits excellent fluorescence characteristics.Subsequently,the Tm:YAG thin film is processed using focused ion beam to form microdisks with a diameter of 30μm.Under 785 nm laser pumping,the maximum output power of the Tm:YAG microdisk at 2023.1 nm is229μW,with a slope efficiency of 2.9%.This work demonstrates the outstanding potential of Tm:YAG as a mid-infrared laser gain medium,providing a new option for the development of mid-infrared lasers.

关键词： microdisk microlaser ultrathin film

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Quantum nonlocality evolution for two entangled mesoscopic fields under decoherence

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Communications in Theoretical Physics 2024年第1期76卷 24-28页

作者： Zhao-Song tan Shou-Bang yang Zhen-Biao yang Shi-Biao Zheng Fujian Key Laboratory of Quantum Information and Quantum Optics Fuzhou UniversityFuzhouFujian 350116China

Investigation of the nonlocality evolution of entangled mesoscopic fields under decoherence not only is important for understanding the quantum–classical transition,but also has relevance to quantum communication and quantum computation protocols based on continuous variables.According to previous formulations of Bell inequalities,the system loses nonlocal features far before the disappearance of entanglement.We here construct a new version of Bell signal based on rotated and displaced on–off correlations,with which the Bell inequality is violated as long as there remains entanglement and the field state components keep quasiorthogonal.Consequently,the nonlocal character revealed by our formulation decays much slower compared with those based on previous ones.More importantly,there exists a wide regime where the Bell inequality is restored with previous formulations but remains to be violated based on our correlation operators.

关键词： entangled mesoscopic fields rotated and displaced on-off correlations Bell inequality nonlocality evolution

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Sliding and damming properties of granular debris with different geometric configurations and grain size distributions

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Journal of Mountain Science 2024年第3期21卷 932-951页

作者： HE Ligeng tan Longmeng yang Xingguo ZHOU Jiawen LIAO Haimei College of Civil Engineering Guizhou UniversityGuiyang 550025China Quality Supervision and Law Enforcement Detachment of Guizhou Province Traffic Construction Engineering Guiyang 550081China State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan UniversityChengdu 610065China

Granular debris plays a significant role in determining damming deposit characteristics. An indepth understanding of how variations in grain size distribution(GSD) and geometric configurations impact the behavior of granular debris during the occurrence of granular debris is essential for precise assessment and effective mitigation of landslide hazards in mountainous terrains. This research aims to investigate the impact of GSD and geometric configurations on sliding and damming properties through laboratory experiments. The geometric configurations were categorized into three categories based on the spatial distribution of maximum volume: located at the front(Type Ⅰ), middle(Type Ⅱ), and rear(Type Ⅲ) of the granular debris. Our experimental findings highlight that the sliding and damming processes primarily depend on the interaction among the geometric configuration, grain size, and GSD in granular debris. Different sliding and damming mechanisms across various geometric configurations induce variability in motion parameters and deposition patterns. For Type Ⅰ configurations, the front debris functions as the critical and primary driving component, with energy dissipation primarily occurring through inter-grain interactions. In contrast, Type Ⅱ configurations feature the middle debris as the dominant driving component, experiencing hindrance from the front debris and propulsion from the rear, leading to complex alterations in sliding motion. Here, energy dissipation arises from a combination of inter-grain and grain-substrate interactions. Lastly, in Type Ⅲ configurations, both the middle and rear debris serve as the main driving components, with the rear sliding debris impeded by the front. In this case, energy dissipation predominantly results from grainsubstrate interaction. Moreover, we have quantitatively demonstrated that the inverse grading in damming deposits, where coarse grain moves upward and fine grain moves downward, is primarily caused by grain sorting due to collisions among the grains and between

关键词： Landslide dam Geometric configuration Energy dissipation Inverse grading Physical experiment

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Mpox(formerly monkeypox):pathogenesis,prevention,and treatment

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Signal Transduction and Targeted Therapy 2024年第1期9卷 234-248页

作者： Junjie Lu Hui Xing Chunhua Wang Mengjun tang Changcheng Wu Fan Ye Lijuan Yin yang yang Wenjie tan Liang Shen Xiangyang Central Hospital Affiliated Hospital of Hubei University of Arts and ScienceHubei ProvinceXiangyang 441021China NHC Key Laboratory of Biosafety National Institute for Viral Disease Control and PreventionChinese Center for Disease Control and PreventionBeijing 102206China College of Biotechnology Tianjin University of Science&TechnologyTianjin 300457China Shenzhen Key Laboratory of Pathogen and Immunity National Clinical Research Center for infectious diseaseState Key Discipline of Infectious DiseaseShenzhen Third People’s HospitalSecond Hospital Affiliated to Southern University of Science and TechnologyShenzhen 518112China

In 2022,a global outbreak of Mpox(formerly monkeypox)occurred in various countries across Europe and America and rapidly spread to more than 100 countries and regions.The World Health Organization declared the outbreak to be a public health emergency of international concern due to the rapid spread of the Mpox virus.Consequently,nations intensified their efforts to explore treatment strategies aimed at combating the infection and its dissemination.Nevertheless,the available therapeutic options for Mpox virus infection remain limited.So far,only a few numbers of antiviral compounds have been approved by regulatory authorities.Given the high mutability of the Mpox virus,certain mutant strains have shown resistance to existing pharmaceutical interventions.This highlights the urgent need to develop novel antiviral drugs that can combat both drug resistance and the potential threat of bioterrorism.Currently,there is a lack of comprehensive literature on the pathophysiology and treatment of Mpox.To address this issue,we conducted a review covering the physiological and pathological processes of Mpox infection,summarizing the latest progress of anti-Mpox drugs.Our analysis encompasses approved drugs currently employed in clinical settings,as well as newly identified small-molecule compounds and antibody drugs displaying potential antiviral efficacy against Mpox.Furthermore,we have gained valuable insights from the process of Mpox drug development,including strategies for repurposing drugs,the discovery of drug targets driven by artificial intelligence,and preclinical drug development.The purpose of this review is to provide readers with a comprehensive overview of the current knowledge on Mpox.

关键词： prevention treatment intensified

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On group structures of strategic-form games

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Fundamental Research 2024年第3期4卷 540-549页

作者： Zhigang Cao Guopeng Li Zhibin tan Xiaoguang yang School of Economics and Management Beijing Jiaotong UniversityBeijing 100044China School of Economics Huazhong University of Science and TechnologyWuhan 430074China University of Chinese Academy of Sciences Beijing 100049China MADIS Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100049China

There are two recognized classes of strategic-form symmetric games,both of which can be conveniently defined through the corresponding player symmetry groups.We investigate the basic properties of these groups and several related concepts.We generalize the notion of coveringness and adapt their results to characterize these player symmetry groups.We study the relationships between the coveringnesses of various symmetry groups.Our results demonstrate that these symmetry groups have rich mathematical structures that are of game theoretical and economic interests.

关键词： Noncooperativegames Strategic-form games Symmetricgames Symmetry groups Covering groups

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Three-dimensional morphological and fluorescent imaging of zebrafish with a continuous-rotational light-sheet microscope

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Journal of Innovative Optical Health Sciences 2024年第2期17卷 59-66页

作者： Dongmin Zhang Guang yang Yao tan Chong Chen Jie Zhang Hui Li School of Biomedical Engineering(Suzhou)Division of Life Sciences and Medicine University of Science and Technology of China Hefei 230041 P.R.China Suzhou Institute of Biomedical Engineering and Technology Chinese A cademy of Sciences Suzhou Jiangsu 215163P.R.China

Light-sheet fluorescence microscopy(LSFM)has been widely used to image the three-dimensional(3D)structures and functions of various millimeter-size bio-specimen such as zebrafish.However,the sample adsorption and scattering cause shading of the light-sheet illumination,preventing the even 3D image of thick samples.Herein,we report a continuous-rotational light-sheet microscope(CR-LSM)that enables simultaneous 3D bright-field and fluorescence imaging.With a high-accuracy rotational stage,CR-LSM records the outline projections and the fluorescent images of the sample at multiple rotation angles.Then,3D morphology and fluorescent structure were reconstructed with a developed algorithm.Using CR-LSM,zebrafish’s whole-fish contour and blood vessel structures were obtained simultaneously.

关键词： Light-sheet microscope zebrafish blood vessels morphology

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