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Mechanical properties and damage evolution characteristics of waste tire steel fiber-modified cemented paste backfill

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International Journal of Mining Science and Technology 2024年第7期34卷 909-924页

作者： Cao, Shenggen Che, Chiyuan Zhang, yun Shan, Changhao Liu, Yang zhao, Changzheng Du, Shuyu State Key Laboratory for Fine Exploration and Intelligent Development of Coal Resources School of Mines China University of Mining and Technology Xuzhou 221116 China College of Energy Engineering Xi'an University of Science & Technology Xi'an 710054 China

During the process of constructional backfill mining, the cemented paste backfill (CPB) typically exhibits a high degree of brittleness and limited resistance to failure. In this study, the mechanical and damage evolution characteristics of waste tire steel fiber (WTSF)-modified CPB were studied through uniaxial compression tests, acoustic emission (AE) tests, and scanning electron microscopy (SEM). The results showed that the uniaxial compressive strength (UCS) decreased when the WTSF content was 0.5%, 1%, and 1.5%. When the WTSF content reached 1%, the UCS of the modified CPB exhibited a minimal decrease (0.37 MPa) compared to that without WTSF. When the WTSF content was 0.5%, 1%, and 1.5%, peak strain of the WTSF-modified CPB increased by 18%, 31.33%, and 81.33%, while the elastic modulus decreased by 21.31%, 26.21%, and 45.42%, respectively. The addition of WTSF enhances the activity of AE events in the modified CPB, resulting in a slower progression of the entire failure process. After the failure, the modified CPB retained a certain level of load-bearing capacity. Generally, the failure of the CPB was dominated by tensile cracks. After the addition of WTSF, a gradual increase in the proportion of tensile cracks was observed upon loading the modified CPB sample to the pore compaction stage. The three-dimensional localization of AE events showed that the WTSF-modified CPB underwent progressive damage during the loading, and the samples still showed good integrity after failure. Additionally, the response relationship between energy evolution and damage development of WTSF-modified CPB during uniaxial compression was analyzed, and the damage constitutive model of CPB samples with different WTSF contents was constructed. This study provides a theoretical basis for the enhancement of CPB modified by adding WTSF, serving as a valuable reference for the design of CPB constructional backfill. © 2024

关键词： Steel fibers

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Geometry characteristics and wide temperature behavior of silicon-based GaN surface acoustic wave resonators with ultrahigh quality factor

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Science China(Information Sciences) 2024年第2期67卷 267-278页

作者： Guofang YU Renrong liang Haiming zhao Lei XIAO Jie CUI Yue zhao Wenpu CUI Jing WANG Jun XU Jun FU Tianling REN School of Integrated Circuits Tsinghua University Beijing National Research Center for Information Science Technology Tsinghua University

Surface acoustic wave(SAW) resonators with an ultrahigh Q-factor are designed and fabricated on silicon-based gallium nitride(GaN/Si). The temperature-dependent performance is characterized over a wide range, from 10 to 500 K. Finite element analysis is employed to guide the design of the SAW resonator from indications of the Rayleigh mode and weak propagation direction dependence of SAW in the c-plane of GaN/Si. The SAW resonator with 100 pairs of interdigital transducers(IDT), 100 pairs of grating reflectors(GR) for each side, aperture size of 80 μm, metallization ratio of 0.5, and electrode width of 500 nm resonates at 1.9133 GHz accordingly with an ultrahigh Q-factor of 7622 at room temperature, which contributes the fr× Qr, up to 14.583×1012Hz. A resonator operating over 10 to 500 K indicates an approximately linear decreasing temperature dependence above 280 K while being approximately constant below 40 K. The fitting to resonator characteristics using the modified Butterworth Van Dyke(m BVD) model reveals a reduction in both the electrode and mechanical losses while worsening the dielectric loss with cooling down.

关键词： GaN/Si SAW resonator ultrahigh Q-factor temperature-dependent performance mBVD losses

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Eu-MOF-Based Fluorescent Ratiometric Sensor by Detecting 3,4,5-Trihydroxybenzoic for Fingerprint Visualization on Porous Objects

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Photonic Sensors 2024年第1期14卷 85-98页

作者： Muwen liang Yabin zhao Yaping LUO Bin DU Wei HU Bing LIU Xihui MU zhaoyang TONG Department of Investigation People's Public Security University of ChinaBejing 100038China State Key Laboratory of NBC Protection for Civilian Beijing 102205China

Latent fingerprints(LFPs)at the crime scene are served as important clues to locate the trajectory of criminal behavior and portray the characteristics of the ***,visualizing LFPs is of considerable *** this work,the europium metal-organic framework(Eu-MOF)sensor was successfully constructed for sensitive detection of gallic acid(3,4,5-trihydroxybenzoic acid,GA)and visualization of the sweat *** boric-acid-modified Eu-MOF was prepared by using the simple one-pot solvothermal method using Eu as the metal i ion center and 3,5-dicarboxybenzeneboronic acid(BBDC)as the organic *** sensor showed desirable photoluminescent performance through the chelating of BBDC with Eu3+.The sensor exhibited the satisfactory linear relationship to GA in the range of 1 nM to 20 nM with a low detection limit of 0.34 nM under the optimized *** prepared sensor with ideal selectivity to GA was successfully applied for visualizing LFPs on porous substrates with the high contrast and superior *** the good performance of the sensor,all fingerprint images obtained from 1200 samples presented clear friction ridges and met the identification ***,the sensor had less impact on the subsequent deoxyribonucleic acid(DNA)detection,displaying a promising perspective for applications in extracting physical evidence of site investigation.

关键词： Europium metal-organic framework(Eu-MOF) photoluminescence 3,4,5-trihydroxybenzoic latent fingerprints(LFPs)development

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Oriental Reed Warblers do not abandon Common Cuckoo chicks during prolonged nestling periods

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Avian Research 2024年第3期15卷 369-373页

作者： Hanlin Yan Huahua zhao Haixia Luo Longwu Wang Laikun Ma Wei liang Ministry of Education Key Laboratory for Ecology of Tropical Islands Key Laboratory of Tropical Animal and Plant Ecology of Hainan ProvinceCollege of Life SciencesHainan Normal UniversityHaikou 571158China School of Life Sciences Guizhou Normal UniversityGuiyang 550001China School of Life Sciences Hebei UniversityBaoding 071002China Department of Biology and Food Science Hebei Normal University for Nationaliti

The Oriental Reed Warbler(Acrocephalus orientalis)is one of the most commonly used hosts for the parasitic Common Cuckoo(Cuculus canorus).However,as hosts that feed unrelated parasitic nestlings may suffer extra reproductive costs,they may be less willing to care for nestlings that have prolonged nestling *** test this hypothesis,the duration of feeding by Oriental Reed Warblers under natural conditions for their own nestlings was compared with the duration of feeding under natural conditions for Common Cuckoo nestlings and for artificially prolonged cuckoo *** results showed that Oriental Reed Warblers did not starve,drive away,or desert any of the nestlings in the experiment,and neither parent was left *** experimental study indicates that both Oriental Reed Warbler parents were willing to care for nestlings with a prolonged nestling period(up to 30 days,twice the average duration time that the Oriental Reed Warblers fed their own chicks in natural conditions).However,further experiments and observations are required in other host bird species to examine whether both parents or one of the parents may exhibit the behavior of abandoning nestlings with a prolonged nestling period.

关键词： Brood parasitism Common Cuckoo Deserted nestling Oriental Reed Warbler Prolonged nestling period

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New Insights into Microplastic Contamination in Different Types of Leachates: Abundances, Characteristics, and Potential Sources

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Engineering 2024年第6期37卷 62-68页

作者： Lei Zhang Wentao zhao liang Zhang Zhenxiao Cai Ruiqi Yan Xia Yu Damià Barceló Qian Sui State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process School of Resources and Environmental EngineeringEast China University of Science and TechnologyShanghai 200237China State Key Laboratory of Pollution Control and Resource Reuse College of Environmental Science and EngineeringTongji UniversityShanghai 200092China Shanghai Institute of Pollution Control and Ecological Security Shanghai 200092China PerkinElmer Inc.Shanghai 201203China Maihai Environmental Protection Technology Co. Ltd.SuzhouJiangsu 215000China Department of Environmental Chemistry Institute of Environmental Assessment and Water ResearchSpanish Council for Scientific Research(IDAEA-CSIC)Barcelona 08034Spain

Municipal solid waste(MSW)is an important destination for abandoned *** the waste disposal process,large plastic debris is broken down into microplastics(MPs)and released into the ***,current research only focuses on landfill leachates,and the occurrence of MPs in other leachates has not been ***,herein,the abundance and characteristics of MPs in three types of leachates,namely,landfill leachate,residual waste leachate,and household food waste leachate,were studied,all leachates were collected from the largest waste disposal center in *** results showed that the average MP abundances in the different types of leachates ranged from(129±54)to(1288±184)MP particles per liter(particlesL1)and the household food waste leachate exhibited the highest MP abundance(p80%)of small MPs(20–100 lm)in landfill leachates compared to other *** the best of our knowledge,this is the first study discussing the sources of MPs in different leachates,which is important for MP pollution control during MSW disposal.

关键词： Microplastics Landfill leachate Residual waste leachate Household food waste leachate Source

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Development of wet adhesion of honeybee arolium incorporated polygonal structure with three-phase composite interfaces

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Friction 2024年第2期12卷 215-230页

作者： Lulu liang Jieliang zhao Qun NIU Li YU Xiangbing WU Wenzhong WANG Shaoze YAN Zhenglei YU School of Mechanical Engineering Beijing Institute of TechnologyBeijing 100081China Division of Intelligent and Biomechanical Systems State Key Laboratory of TribologyDepartment of Mechanical EngineeringTsinghua UniversityBeijing 100084China Key of Bionic Engineering Ministry of EducationJilin UniversityChangchun 130022China

Inspired by the dynamic wet adhesive systems in nature,various artificial adhesive surfaces have been developed but still face different ***,the theoretical mechanics of wet adhesives has never been sufficiently ***,we develop a novel adhesive mechanism for governing wet adhesion and investigate the biological models of honeybee arolium for reproducing the natural wet adhesive ***-nano structures of honeybee arolium and arolium-prints were observed by Cryogenic scanning electron microscopy(Cryo-SEM),and the air pockets were found in the contact interface ***,the adhesive models with a three-phase composite interface(including air pockets,liquid secretion,and hexagonal frames of arolium),were formed to analyze the wet adhesion of honeybee *** results of theoretical calculations and experiments indicated an enhanced adhesive mechanism of the honeybee by liquid self-sucking effects and air-embolism *** these effects,normal and shear adhesion can be adjusted by controlling the proportion of liquid secretion and air pockets in the contact ***,the air-embolism effects contribute to the optimal coupling of smaller normal adhesion with greater shear adhesion,which is beneficial for the high stride frequency of *** works can provide a fresh perspective on the development of bio-inspired wet adhesive surfaces.

关键词： honeybee arolium air pockets wet adhesion a three-phase interface self-sucking effects air-embolism effects

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Coupled CFD-DEM Numerical Simulation of the Interaction of a Flow-Transported Rag with a Solid Cylinder

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Fluid Dynamics & Materials Processing 2024年第7期20卷 1593-1609页

作者： yun Ren Lianzheng zhao Xiaofan Mo Shuihua Zheng Youdong Yang Zhijiang College Zhejiang University of TechnologyShaoxing312030China College of Mechanical Engineering Zhejiang University of TechnologyHangzhou310032China

A coupled Computational Fluid Dynamics-Discrete Element Method(CFD-DEM)approach is used to calculate the interaction of a flexible rag transported by a fluid current with a fixed solid *** specifically a hybrid Eulerian-Lagrangian approach is used with the rag being modeled as a set of interconnected *** influence of various parameters is considered,namely the inlet velocity(1.5,2.0,and 2.5 m/s,respectively),the angle formed by the initially straight rag with the flow direction(45°,60°and 90°,respectively),and the inlet position(90,100,and 110 mm,respectively).The results show that the flow rate has a significant impact on the permeability of the *** higher the flow rate,the higher the permeability and the rag speed *** angle has a minor effect on rag permeability,with 45°being the most favorable angle for *** inlet position has a small impact on rag permeability,while reducing the initial distance between the rag an the cylinder makes it easier for rags to pass through.

关键词： Rag flow around cylinder flow characteristics numerical simulation

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Switching on/off phosphorescent or non-radiative channels by aggregation-induced quantum interference

Aggregate

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Aggregate 2024年第1期5卷 175-184页

作者： Yi Kong Yu-Chen Wang Xunkun Huang WanZhen liang Yi zhao Department of Chemistry State Key Laboratory of Physical Chemistry of Solid SurfacesiChEMFujian Provincial Key Laboratory of Theoretical and Computational Chemistryand College of Chemistry and Chemical EngineeringXiamen UniversityXiamenPeople’s Republic of China

Pure organic materials with persistent and efficient room-temperature phosphorescence have recently aroused great research interest due to their vast potential in *** crucial design principle for such materials is to suppress as much as possible the non-radiative decay of the triplet exciton while maintaining a moderate phosphorescent radiative ***,molecular engineering often exhibits similar regulation trends for the two ***,we propose that the quantum interference caused by aggregation can be utilized to control the phosphorescent and non-radiative decay *** systematically analyze various constructive and destructive transition pathways in aggregates with different molecular packing types and establish clear relationships between the luminescence characters and the signs of the singlet and triplet excitonic *** is shown that the decay channels can be flexibly switched on or off by regulating the packing type and excitonic *** importantly,an enhanced phosphorescent decay and a completely suppressed non-radiative decay can be simultaneously realized in the aggregate packed with inversion *** work lays the theoretical foundation for future experimental realization of quantum interference effects in phosphorescence.

关键词： excitonic coupling intersystem crossing organic aggregates organic room temperature phosphorescence quantum interference

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The mediatory role of water quality on the association between extreme precipitation events and infectious diarrhea in the Yangtze River Basin,China

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Fundamental Research 2024年第3期4卷 495-504页

作者： Junfeng Yu liang zhao Xin-Zhong liang Hung Chak Ho Masahiro Hashizume Cunrui Huang School of Public Health Sun Yat-sen UniversityGuangzhou 510080China The State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics(LASG) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Department of Atmospheric and Oceanic Science University of MarylandCollege ParkMD 20740USA Department of Public and International Affairs City University of Hong KongHong Kong 999077China Department of Global Health Policy Graduate School of MedicineThe University of TokyoTokyo 113-0033Japan Vanke School of Public Health Tsinghua UniversityBeijing 100084China Institute of Healthy China Tsinghua UniversityBeijing 100084China

Extreme precipitation is exacerbating the burden of infectious diarrhea in the context of climate change,it is necessary to identify the critical and easy-to-intervene intermediate factors for public health *** quality may be the most important mediator,while relevant empirical evidence is *** study aimed to examine the role of water quality in the process of infectious diarrhea caused by extreme *** infectious diarrhea cases,meteorological factors and water quality data in Yangtze River Basin in China between October 29,2007 to February 19,2017 were ***-stage statistical models were used to estimate city-specific extreme precipitation,water quality and infectious diarrhea relationships that were pooled to derive regional estimates.A causal mediation analysis was used to assess the mediation effect of water *** Yangtze River Basin,extreme precipitation events had a significant impact on infectious diarrhea(Incidence Rate Ratios[IRR]:1.027,95%Confidence Interval[CI]:1.013~1.041).After extreme precipitation events,the dissolved oxygen(DO)in surface water decreased(-0.123 mg/L,95%CI:-0.159 mg/L~-0.086 mg/L),while the un-ionized ammonia(NH(3)-N)increased(0.004 mg/L,95%CI:0.001 mg/L~0.006 mg/L).The combined overall effect of DO and NH(3)-N on infectious diarrhea showed that both low and high concentrations were associated with an increased risk of infectious *** causal mediation analysis showed that the mediation proportion of the two water quality indexes(DO and NH(3)-N)is 70.54%(P<0.001).To reduce the health effects of extreme precipitation,in contrast to current population-oriented health strategies,those that take into account more direct and easy-to-intervene water quality indicators should be encouraged by future policies.

关键词： Extreme precipitation Infectious diarrhea Water quality Dissolved oxygen Un-ionized ammonia Mediation analysis

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Train post‑derailment behaviours and containment methods:a review

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Railway Engineering Science 2024年第1期32卷 59-80页

作者： zhao Tang Yuwei Hu Shuangbu Wang liang Ling Jianjun Zhang Kaiyun Wang State Key Laboratory of Traction Power Southwest Jiaotong UniversityChengdu 610031China Institute of Smart City and Intelligent Transportation Southwest Jiaotong UniversityChengdu 610031China National Centre for Computer Animation Bournemouth UniversityDorsetUK

Railway accidents,particularly serious derailments,can lead to catastrophic ***,it is essential to prevent derailment escalation to reduce the likelihood of severe *** post-derailment behaviours and containment methods play a critical role in preventing derailment escalation and providing passive safety protection and accident prevention in the event of a ***,despite the increasing attention on this field from academia and industry in recent years,there is a lack of systematic exploration and summarization of emerging applications and containment methods in train post-derailment *** this reason,this paper presents a comprehensive review of existing studies on train post-derailment behaviours,encompassing various topics such as post-derailment contact-impact models,dynamic modelling and simulation techniques,and the primary factors influencing post-derailment ***,this review introduces and elucidates substitute guidance mechanisms(SGMs),which serve as railway-specific passive safety protection and accident prevention *** various types of SGMs are depicted,and their ongoing developments and applications are explored in *** review additionally points out several unresolved challenges including the adverse effects of SGMs,and proposes future research directions to advance the theoretical understanding and practical application of train post-derailment behaviours and containment *** review seeks to be a valuable reference for railway industry professionals in preventing catastrophic derailment consequences through post-derailment containment methods.

关键词： Railway passive safety Railway accident prevention Post-derailment behaviours Substitute guidance mechanisms(SGMs) Contact-impact model

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