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Friction 2024年第1期12卷 74-94页

作者： Jiabao yin chun LU Jiliang MO School of Mechanical Engineering Southwest Jiaotong UniversityChengdu 610031China Technology and Equipment of Rail Transit Operation and Maintenance Key Laboratory of Sichuan Province Chengdu 610031China

A comprehensive modeling strategy for studying the thermomechanical tribological behaviors is proposed in this work.The wear degradation considering the influence of temperature(T)is predicted by Archard wear model with the help of the UMESHMOTION subroutine and arbitrary Lagrangian–Eulerian(ALE)remeshing technique.Adopting the proposed method,the thermomechanical tribological behaviors of railway vehicle disc brake system composed of forged steel brake disc and Cu-based powder metallurgy(PM)friction block are studied systematically.The effectiveness of the proposed methodology is validated by experimental test on a self-designed scaled brake test bench from the perspectives of interface temperature,wear degradation,friction noise and vibration,and contact status evolution.This work can provide an effective way for the investigation of thermomechanical tribological behaviors in the engineering field.

关键词： tribological behaviors thermomechanical field wear prediction finite element simulation disc brake system railway vehicle

Progress of additives for morphology control in organic photovoltaics

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Chinese Chemical Letters 2024年第6期35卷 38-46页

作者： Zhongjie Li Xiangyue Kong Yuhao Liu Huayu Qiu Lingling Zhan shouchun yin Key Laboratory of Organosilicon Chemistry and Materials Technology of Ministry of Education College of MaterialChemistry and Chemical EngineeringHangzhou Normal UniversityHangzhou 311121China

The microstructure of the active layer in organic photovoltaics(OPVs),such as the size of phase separation,purity of the phases,and molecular packing within each phase,plays a crucial role in influencing the behavior of excitons and charge carriers within the active layer.It is also a key determinant of the photovoltaic performance of the device.During the optimization of OPV devices,the use of additives has been demonstrated to be an effective strategy in microstructure control,leading to enhanced performance.Therefore,the quest for stable and efficient novel additives,along with an exploration and summarization of the mechanisms underlying additive-induced microstructure control,is essential for a better understanding of the developmental trends of high-performance additives.In this review,we categorize additives based on their chemical structures and discuss their effects on the microstructure of the active layer from both thermodynamic and kinetic perspectives.Furthermore,we elaborate on the working mechanisms and their impact on the photovoltaic performance of the devices.This review provides an overview of recent advances in additives for OPVs,offering potential guidance for the future development of additives and further optimization of the active layer in photovoltaic devices.

关键词： Organic photovoltaics Additives Active layer morphology Mechanisms Photovoltaic performances

Phase-field lattice-Boltzmann study on fully coupled thermal-solute-convection dendrite growth of Al-Cu alloy

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China Foundry 2024年第2期21卷 125-136页

作者： yin-qi Qiu Meng-wu Wu Xun-peng Qin shou-mei Xiong Hubei Key Laboratory of Advanced Technology for Automotive Components Wuhan University of TechnologyWuhan 430070China Hubei Longzhong Laboratory Xiangyang 441000HubeiChina School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China

Dendrite growth is a complex liquid-solid phase transition process involving multiple physical factors.A phase-field lattice-Boltzmann method was developed to simulate the two-and three-dimension dendrite growth of Al-Cu alloy.The effect of fully coupled thermal-solute-convection interaction on the dendrite growth was investigated by incorporating a parallel-adaptive mesh refinement algorithm into the numerical model.By accurately reproducing the latent heat release,solute diffusion and convective transport behaviors at the liquidsolid interface,the interaction mechanism among thermal-solute-convection transport as well as their coupling effects on the dendrite growth dynamics were discussed.The simulation results show that the release of latent heat slows down the dendrite growth rate,and both natural and forced convection disrupt the symmetrical growth of dendrites.Their combination makes the growth of dendrites more complex,capturing important physical aspects such as recalescence,dendrite tip splitting,dendrite tilting,dendrite remelting,and solute plume in the simulation case.Based on the robustness and powerful ability of the numerical model,the formation mechanisms of these physical aspects were revealed.

关键词： simulation phase field dendrite growth thermal-solute-convection interaction

Influence of Transportation Accessibility on Urban-rural Income Disparity and Its Spatial Heterogeneity

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Chinese Geographical Science 2024年第3期34卷 453-467页

作者： HUANG Xiaoyan KANG Chenchen yin chun TANG Junqing Northwest Land and Resources Research Center Global Regional and Urban Research InstituteShaanxi Normal UniversityXi’an 710119China School of Resource and Environmental Sciences Wuhan UniversityWuhan 430079China International Institute of Spatial Lifecourse Health(ISLE) Wuhan UniversityWuhan 430079China School of Urban Planning and Design Shenzhen Graduate SchoolPeking UniversityShenzhen 518055China Key Laboratory of Earth Surface System and Human-Earth Relations of Ministry of Natural Resources of China Shenzhen Graduate SchoolPeking UniversityShenzhen 518055China

Transportation accessibility has been treated as an important means of reducing the urban-rural income disparity.However,only a few studies have examined the effects of different types of transportation accessibility on urban-rural income disparity and their spatial heterogeneity.Based on data from 285 prefecture-level(and above)Chinese cities in 2000,2005,2010,2015,and 2020,this study uses spatial econometric models to examine how highway accessibility and railway accessibility influence the urban-rural income disparity and to identify their spatial heterogeneity.The result reveals that highway accessibility and railway accessibility have‘coreperiphery’ring-like circle structures.The urban-rural income disparity exhibits strong spatial clustering effects.Both highway accessibility and railway accessibility are negatively associated with urban-rural income disparity,and the former having a greater effect size.Moreover,there is a substitution effect between highway accessibility and railway accessibility in the whole sample.Furthermore,these associations differ in geographic regions.In the central region,highway accessibility is more important in reducing the urban-rural income disparity,but its effect is weakened with the increase of railway accessibility.In the western region,railway accessibility has a larger effect on narrowing the urban-rural income disparity,and this effect is strengthened by the increase of highway accessibility.We conclude that improving transportation accessibility is conducive to reducing the urban-rural income disparity but its effect is spatial heterogenetic.Highways and railways should be developed in a coordinated manner to promote an integrated transport network system.

关键词： transport accessibility income gap regional divergence spatial heterogeneity urban and rural areas China

Constructing a 3D multichannel structure to enhance performance of Ni–Co–Mn hydroxide electrodes for flexible supercapacitors

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Rare Metals 2024年第1期43卷 148-163页

作者： Zhi-Hui Xu Shi-Shuai Sun Xue-Lei Li Zhi-Hui Zhang Hai-ying Li Shuang-Ting Ruan shou-Gen yin Key Laboratory of Display Materials and Photoelectric Devices(Ministry of Education)and Tianjin Key Laboratory for Photoelectric Materials and Devices School of Materials Science and EngineeringTianjin University of TechnologyTianjin 300384China College of Science Tianjin University of TechnologyTianjin 300384China School of Materials Science and Engineering Inner Mongolia University of TechnologyHohhot 010051China

The balancing of the electrochemical performance,mechanical stability,and processing technology for applying supercapacitors to flexible and wearable electronics continues to encounter severe challenges.Herein,we prepare Ni-Co-Mn hydroxide electrodes with a threedimensional multichannel structure via a simple hydrothermal method.These are constructed using vertically contiguous nano sheets with a uniform thickness and rough surface.The electrodes can provide numerous electroactive sites and accelerate the transmission of electrolyte ions.The relationship between the structure and electrochemical performances is verified by experiments and theoretical calculations.Two-dimensional(2D)planar and one-dimensional(1D)fiber electrodes are prepared using a flexible carbon cloth(CC)and carbon fiber(CF),respectively,as substrates.The assembled quasi-solid-state flexible asymmetric supercapacitor(FASC)with a twodimensional sandwich structure using NiCoMn-OH/CC as the electrode achieves a remarkable energy density of73.8 Wh·kg^(-1)at a power density of 1.03 kW·kg^(-1).The quasi-solid-state FASC with a 1D linear structure using NiCoMn-OH/CF as the electrode also attains a high energy density(12.9 Wh·kg^(-1)at a power density of0.75 W·kg^(-1)).Moreover,the electrochemical performances of the NiCoMn/CC//AC/CC and NiCoMn/CF//AC/CF FASCs are not disturbed at different bending angles(0°,45°,90°,135°and 180°),This indicates the superior flexibility of the devices.We also assemble a self-powered energy-harvesting storage system by integrating FASCs and commercial solar cells to verify its practicability.It displays sustainable development potential for energy storage.

关键词： Supercapacitors Flexible Ni–Co–Mn hydroxide 3D multichannel structure High performances

RB-DEM Modeling and Simulation of Non-Persisting Rough Open Joints Based on the IFS-Enhanced Method

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Computer Modeling in Engineering & Sciences 2024年第4期139卷 337-359页

作者： Hangtian Song Xudong Chen chun Zhu Qian yin Wei Wang Qingxiang Meng Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering Hohai UniversityNanjing210098China Research Institute of Geotechnical Engineering Hohai UniversityNanjing210098China School of Earth Sciences and Engineering Hohai UniversityNanjing210098China State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and TechnologyXuzhou221116China

When the geological environment of rock masses is disturbed,numerous non-persisting open joints can appear within it.It is crucial to investigate the effect of open joints on the mechanical properties of rock mass.However,it has been challenging to generate realistic open joints in traditional experimental tests and numerical simulations.This paper presents a novel solution to solve the problem.By utilizing the stochastic distribution of joints and an enhanced-fractal interpolation system(IFS)method,rough curves with any orientation can be generated.The Douglas-Peucker algorithm is then applied to simplify these curves by removing unnecessary points while preserving their fundamental shape.Subsequently,open joints are created by connecting points that move to both sides of rough curves based on the aperture distribution.Mesh modeling is performed to construct the final mesh model.Finally,the RB-DEM method is applied to transform the mesh model into a discrete element model containing geometric information about these open joints.Furthermore,this study explores the impacts of rough open joint orientation,aperture,and number on rock fracture mechanics.This method provides a realistic and effective approach for modeling and simulating these non-persisting open joints.

关键词： Non-persisting rough open joints stochastic distribution of joints enhanced-IFS method RB-DEM

Quasi-two dimensional Ruddlesden−Popper halide perovskites for laser applications

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Frontiers of physics 2024年第2期19卷 53-71页

作者： Kun Chen Qianpeng Zhang yin Liang Jiepeng Song chun Li Shi Chen Fang Li Qing Zhang School of Mechanical and Electrical Engineering Wuhan Institute of TechnologyWuhan 430205China School of Materials Science and Engineering Peking UniversityBeijing 100871China Institute of Applied Physics and Materials Engineering Macao UniversityMacao 999078China

Quasi-two-dimensional(2D)Ruddlesden‒Popper(RP)halide perovskites,as a kind of emerged two-dimensional layered materials,have recently achieved great attentions in lasing materials field owing to their large exciton binding energy,high emission yield,large optical gain,and wide-range tuning of optical bandgap.This review will introduce research progresses of RP halide perovskites for lasing applications in aspects of materials,photophysics,and devices with emphasis on emission and lasing properties tailored by the molecular composition and interface.The materials,structures and fabrications are introduced in the first part.Next,the optical transitions and amplified spontaneous emission properties are discussed from the aspects of electronic structure,exciton,gain dynamics,and interface tailoring.Then,the research progresses on lasing devices are summarized and several types of lasers including VCSEL,DFB lasers,microlasers,random lasers,plasmonic lasers,and polariton lasers are discussed.At last,the challenges and perspectives would be provided.

关键词： two-dimensional materials metal halide perovskite Ruddlesden−Popper halide perovskites lasing emission

Machine learning-based predictions of current and future susceptibility to retrogressive thaw slumps across the Northern Hemisphere

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Advances in Climate Change Research 2024年第2期15卷 253-264页

作者： Jing LUO Guo-An yin Fu-Jun NIU Tian-chun DONG Ze-Yong GAO Ming-Hao LIU Fan YU State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China China Railway Qinghai-Tibet Group Co. LtdXining 810000China University of Chinese Academy of Sciences Beijing 100049China

Retrogressive thaw slumps(RTSs)caused by the thawing of ground ice on permafrost slopes have dramatically increased and become a common permafrost hazard across the Northern Hemisphere during previous decades.However,a gap remains in our comprehensive understanding of the spatial controlling factors,including the climate and terrain,that are conducive to these RTSs at a global scale.Using machine learning methodologies,we mapped the current and future RTSs susceptibility distributions by incorporating a range of environmental factors and RTSs inventories.We identified freezing-degree days and maximum summer rainfall as the primary environmental factors affecting RTSs susceptibility.The final ensemble susceptibility map suggests that regions with high to very high susceptibility could constitute(11.6±0.78)%of the Northern Hemisphere's permafrost region.When juxtaposed with the current(2000-2020)RTSs susceptibility map,the total area with high to very high susceptibility could witness an increase ranging from(31.7±0.65)%(SSP585)to(51.9±0.73)%(SSP126)by the 2041-2060.The insights gleaned from this study not only offer valuable implications for engineering applications across the Northern Hemisphere,but also provide a long-term insight into the potential change of RTSs in permafrost regions in response to climate change.

关键词： Retrogressive thaw slump Machine learning Susceptibility map Permafrost Northern Hemisphere

Environmental factors controlling soil warming and wetting during 2000-2020 in permafrost and non-permafrost regions across the Qinghai-Tibet Plateau

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Advances in Climate Change Research 2024年第2期15卷 285-296页

作者： Guo-An yin Jing LUO Fu-Jun NIU Ming-Hao LIU Ze-Yong GAO Tian-chun DONG Wei-Heng NI State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China China Railway Qinghai-Tibet Group Co. Ltd.Xining 810000China University of Chinese Academy of Sciences Beijing 100049China

The Qinghai-Tibet Plateau(QTP)has experienced rapid environmental changes,including climate warming and wetting,since the 1980s.These environmental changes significantly impact the shallow soil hydrothermal conditions,which have key roles in land-atmosphere feedback and ecosystem functions.However,the spatial variations and responses of soil hydrothermal conditions to environmental changes over the QTP with permafrost(PF)and seasonal frost(SF)remain unclear.In this study,we investigated the spatial variations in soil temperature(ST)and soil moisture(SM)changes over the QTP from 2000 to 2020 using 99 in-situ sites with observations at 4 depths(i.e.10,40,100 and 200 cm).The main environmental controlling factors were further identified using a calibrated statistical model.Results showed that significant(p<0.05)soil warming occurred at multiple soil layers during 2000-2020 with a wide variation(i.e.0.033-0.039℃ per year on average),whereas the warming rates at PF sites were two times greater than those at SF sites.In addition,the soil wetting rate was high over the SF region,whereas the soil wetting rate was low over the PF region.Aside from air temperature,changes in thawing degree days and solar radiation(Srad)contributed most to soil warming in the PF region,whereas changes in rainfall,Srad and evaporation(EVA)have been identified as the key factors in the SF region.As for soil wetting,changes in snowfall,freezing degree days and vegetation have noticeable nonlinear effects over the PF region,whereas changes in EVA,Srad and rainfall highlighted distinct linear and nonlinear effects in the SF region.These findings enhance our understanding of the hydrothermal impacts of future environmental changes over the QTP.

关键词： Warming amd wetting Soil hydrothermal change Factor Permafrost Seasonal frost

Nutrient transport following water transfer through the world's largest water diversion channel

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Journal of Environmental Sciences 2024年第1期135卷 703-714页

作者： Yuanhui Cheng Hong Zhang Wei yin State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085 China Changjiang Water Resources Protection Institute Wuhan 430051China University of Chinese Academy of Sciences Beijing 100049China

Nutrient levels in the artificial channel constructed for the Middle Route Project are significant indicators of water quality safety and aquatic ecological integrity for this large,interbasin scheme.However,the distribution and transport of nutrients along the channel were poorly understood.Based on a time-series dataset as well as mass balance and material flow analysis methods,the water and nutrient transport fluxes in the Middle Route of the South-to-North Water Diversion Project were identified in this study.The results indicate that the nutrient concentrations varied considerably with time,but there was no significant difference among the 30 stations of the main channel.Seasonal temperature difference was the major factor in the large fluctuations of water quality indicators over time.The nutrient loadings varied with the water volume outputs from the main channel to the waterreceiving cities.Atmospheric deposition was an important source of nutrients in the main channel,accounting for 9.13%,20.6%,and 0.635%of the nitrogen,phosphorus,and sulfur input from the Danjiangkou Reservoir,respectively.In 2021,a net accumulation of 988 tons of N,29 tons of P,and 2,540 tons of S,respectively,were present in the main channel.The increase of these external and internal nutrient loadings would cause water quality fluctuation and deterioration in some local sections of the main channel.Our study quantified the spatial and temporal patterns of nutrient transport in the Middle Route and revealed the ecological effects on the aquatic environment,assisting authorities on the project to develop effective water conservation strategies.

关键词： Nutrient transport Spatiotemporal patterns The Middle Route The South-to-North Diversion Project Hydro-ecological effects Water-receiving cities