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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： Shenggen Cao Chiyuan che Yun Zhang Changhao Shan Yang Liu Changzheng Zhao Shuyu Du State Key Laboratory for Fine Exploration and Intelligent Development of Coal Resources School of MinesChina University of Mining and TechnologyXuzhou 221116China College of Energy Engineering Xi’an University of Science&TechnologyXi’an 710054China

During the process of constructional backfill mining,the cemented paste backfill(CPB)typically exhibits a high degree of brittleness and limited resistance to *** 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 *** 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%,*** addition of WTSF enhances the activity of AE events in the modified CPB,resulting in a slower progression of the entire failure *** the failure,the modified CPB retained a certain level of load-bearing ***,the failure of the CPB was dominated by tensile *** 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 *** 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 ***,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 *** 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.

关键词： Constructional backfill Cemented paste backfill Waste tire steel fiber Acoustic emission Damage characteristics

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Sustainable Seawater Desalination and Energy Management:Mechanisms,Strategies,and the Way Forward

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Research 2024年第3期2023卷 595-611页

作者： Meng Wang Yen Wei Ruoxin Li Xin Wang chengyu Wang Nanqi Ren Shih-hsin Ho State Key Laboratory of Urban Water Resource and Environment School of EnvironmentHarbin Institute of TechnologyHarbin 150001China Department of chemistry Tsinghua UniversityBeijing 100084China Key Laboratory of Bio-based Material Science&Technology(Northeast Forestry University) Ministry of EducationHarbin 150040China.

Solar-driven desalination systems have been recognized as an effective technology to address the water ***,evaporators prepared based on advanced manufacturing technologies have emerged as a promising tool in enhancing ocean energy *** this review,we discussed the thermal conversion,energy flow,salt deposition mechanisms,and design strategies for solar-driven desalination systems,and explored how to improve the desalination performance and energy use efficiency of the systems through advanced manufacturing *** future perspectives,we determined the feasibility of coupling solar-driven solar desalination systems with multi-stage energy utilization systems and emerging artificial intelligence technologies,for which conclusions are given and new directions for future desalination system development are ***,exciting opportunities and challenges in the face of basic research and practical implementation are discussed,providing promising solutions and blueprints for green and novel desalination technologies while achieving sustainable development.

关键词： Sustainable Solar directions

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Optimal Timing of Business Conversion for Solvency Improvement

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Acta Mathematicae Applicatae Sinica 2024年第3期40卷 744-757页

作者： Peng LI ming ZHOU School of Finance Nanjing University of Finance and EconomicsNanjing 210023China Center for Applied Statistics and School of Statistics Renmin University of ChinaBeijing 100872China

In this paper,we study the optimal timing to convert the risk of business for an insurance company in order to improve its *** cash flow of company evolves according to a jump-diffusion *** conversion option offers the company an opportunity to transfer the jump risk business *** exchange for this option,the company needs to pay both fixed and proportional transaction *** proportional cost can also be seen as the profit loading of the jump risk *** formulated this problem as an optimal stopping *** solving this stopping problem,we find that the optimal timing of business conversion mainly depends on the profit loading of the jump risk business.A larger profit loading would make the conversion option *** fixed cost,however,only delays the optimal timing of business *** the end,numerical results are provided to illustrate the impacts of transaction costs and environmental parameters to the optimal strategies.

关键词： optimal stopping jump-diffusion process conversion option

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The Contribution of United States Aircraft Reconnaissance Data to the China Meteorological Administration Tropical Cyclone Intensity Data:An Evaluation of Homogeneity

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Advances in Atmospheric Sciences 2024年第4期41卷 639-654页

作者： ming YING Xiaoqin LU Shanghai Typhoon Institute China Meteorological AdministrationShanghai 200030China

This paper investigates the homogeneity of United States aircraft reconnaissance data and the impact of these data on the homogeneity of the tropical cyclone(TC)best track data for the seasons 1949-1987 generated by the China Meteorological Administration(CMA).The evaluation of the reconnaissance data shows that the minimum central sea level pressure(MCP)data are relatively homogeneous,whereas the maximum sustained wind(MSW)data show both overestimations and spurious abrupt *** comparisons suggest that both the reconnaissance MCP and MSW were well incorporated into the CMA TC best track *** no spurious abrupt changes were evident in the reconnaissance-related best track MCP data,two spurious changepoints were identified in the remainder of the best-track MCP ***,the influence of the reconnaissance MSWs seems to extend to the best track MSWs unrelated to reconnaissance,which might reflect the optimistic confidence in making higher estimates due to the overestimated extreme wind“observations”.In addition,the overestimation of either the reconnaissance MSWs or the best track MSWs was greater during the early decades compared to later decades,which reflects the important influence of reconnaissance data on the CMA TC best track *** wind-pressure relationship(WPR)used in the CMA TC best track dataset is also evaluated and is found to overestimate the MSW,which may lead to inhomogeneity within the dataset between the aircraft reconnaissance era and the satellite era.

关键词： tropical cyclone intensity homogeneity best track aircraft reconnaissance

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Fluorescent carbon dots synthesized in solid phase and air for application in LEDs

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Nano Research 2024年第9期17卷 8495-8503页

作者： Wei-Jie Zheng Zhao-Nan Sun Yi-ming Wang Huan-ming Xiong Department of chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Fudan UniversityShanghai 200438China

Carbon dots(CDs)have been widely adopted as optical materials because of their excellent luminescent ***,most of the reported synthetic methods are conducted in solvents,especially hydrothermal/solvothermal reactions,leading to intractable problems such as toxic and flammable solvents,complex and inseparable by-products,and dangerously high pressures and ***-phase synthesis of CDs in air is an effective solution to overcome the above issues,but solid reactions always result in uncontrolled growth and agglomeration of *** this study,some inorganic salts are selected as catalysts for synthesizing CDs in solid states and air,which also play as dispersants to hinder CDs *** the meantime,some aromatic derivatives containing hydroxyl and amino groups are chosen as carbon sources,ground with the optimized catalyst,and then heated together in *** production yields are affected by the reaction time and reactant ratio,while the graphitization degrees of the CDs are determined by the reaction *** IG/ID value of their Raman spectra increases from 0.59 to 0.85,and the particle size decreases from 2.5 to 1.4 nm when the synthesis temperature is increased from 200 to 280℃.The as-prepared CDs show emission peaks ranging from 366 to 606 nm,with the photoluminescence(PL)quantum yield up to 53%.Their emission color variation mainly results from different carbon sources,which can be ascribed to the differences in the element composition,functional groups,and graphitic nitrogen content of these *** dispersing CDs of different concentrations into polyvinyl alcohol(PVA)and combining them with blue LEDs,cold,standard,and warm white light emitting devices(WLEDs)are prepared,with a color rendering index(CRI)up to *** the as-prepared CDs have antioxidant ability at high temperature,the as-prepared WLEDs have long lifespans,remaining the effective white luminescence after 72 h continuous work.

关键词： carbon dot solid-phase synthesis white LED photoluminescence inorganic salt catalysis

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Determination of multilevel chirality in nickel molybdate films by electron crystallography

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Nano Research 2024年第9期17卷 8571-8577页

作者： Jing Ai Yu Wang Liyuan Li Jianqiang Wang Te Bai Shunai che Lu Han Sinopec(Shanghai)Research Institute of Petrochemical Technology Co. Ltd.Shanghai 201208China School of chemical Science and Engineering Tongji UniversityShanghai 200092China School of chemistry and chemical Engineering State Key Laboratory of Metal Matrix CompositesShanghai Jiao Tong UniversityShanghai 200240China

Chiral inorganic materials have attracted great attention owning to their unique physical and chemical properties attributed to the symmetry-breaking of their *** inorganic materials can be endowed with chiral geometric configurations from achiral space group crystals through lattice twisting,screw dislocations or hierarchical self-assembled spiral morphologies,showing various characteristic chiral ***,the multilevel chirality in chiral nickel molybdate films(CNMFs)remains to be elaborately *** this paper,we report three hierarchical levels of chirality in CNMFs,spanning from the atomic to the micron scale,including primary helically coiled nanoflakes with twisted atomic crystal lattices,secondary helical stacking of layered nanoflakes,and tertiary asymmetric morphology between adjacent *** findings may enrich the chiral self-assembly structural types and provide valuable insights for the comprehensive analysis path of hierarchical chiral crystals.

关键词： chiral inorganic material nickel molybdate structural analysis transmission electron microscopy electron crystallography

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Spin chiral anisotropy of diamagnetic chiral mesostructured In_(2)O_(3) films

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Nano Research 2024年第8期17卷 7756-7761页

作者： Ting Ji Quanzheng Deng Hao chen Lu Han Zhibei Qu Shunai che Yingying Duan Frontiers Science Center for Transformative Molecules State Key Laboratory of Metal Matrix CompositesShanghai Key Laboratory for Molecular Engineering of Chiral DrugsSchool of Chemistry and Chemical EngineeringShanghai Jiao Tong UniversityShanghai 200240China School of chemical Science and Engineering Tongji UniversityShanghai 200092China Department of Medicinal chemistry School of PharmacyFudan UniversityShanghai 201203China

Spin chiral anisotropy(SChA)refers to the occurrence of different spin polarization in antipodal chiral ***,we report the SChA in diamagnetic chiral mesostructured In2O3 films(CMIFs)with manifestation of chirality-dependent magnetic circular dichroism(MCD)*** were grown on fluorine-doped tin dioxide conductive glass(FTO)substrates,which were synthesized via a hydrothermal route,with malic acid used as the symmetry-breaking *** levels of chirality have been identified in CMIFs:primary nanoflakes with atomically twisted crystal lattices and secondary helical stacking of the *** exhibit chirality-dependent asymmetric MCD signals due to the different interactions of chirality-induced effective magnetic field and external magnetic field,which distinguish from the commonly observed external magnetic fielddependent symmetric MCD *** findings provide insights into spin manipulation of spin-paired diamagnets.

关键词： chiral inorganics mesostructure diamagnet spin chiral anisotropy(SChA) magnetic circular dichroism(MCD)

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Simulation of temperature distribution in double-row potato ridges mulched with plastic film covered with soil

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International Journal of Agricultural and Biological Engineering 2024年第4期17卷 185-197页

作者： Quandong Liu Wei Sun Yongmei Wang Juanling Wang Xinglong che Mechanical and Electrical Engineering College Gansu Agricultural UniversityLanzhou 730070China Agricultural Machinery Branch of Longxi County Vocational and Technical School Dingxi 748100China Institute of Dryland Agriculture Shanxi Agricultural UniversityTaiyuan 030031China

In Northwest China,potatoes are cultivated on double-rows of each ridge which is mulched with plastic film,and the film is covered with some of *** effective in retaining soil moisture,this technique can render the potato seedlings prone to be burned if they are not released from the plastic film in *** this study,the model of convective heat transfer of potato ridge under solar radiation and atmospheric radiation is established by the Fluent *** processes of the heat transfer of potato ridge was simulated for a certain day,and the temperature distribution in the potato ridge was monitored over *** temperature distribution of soil in the growth layer of potato plants was analyzed under different thickness and widths of the covering soil on the *** results showed that with the increase of covering soil thickness and width,the time for soil at different depth to reach the peak-temperature was delayed,and the daily temperature change of soil where the different depths layer of potato plants growth was *** that time,a binary regression equation of offset temperature was constructed by using the Response Surface *** best parameter combination for covering soil on the plastic film is a thickness of 50 mm and a width of 280 mm in the cold and arid areas of Northwest ***,the offset temperature(PT)first decreased and then almost remained unchanged with the increase of covering soil *** the operational efficiency and power consumption of soil covering devices in the field,the unchanged width of the covering soil is 200 *** field experiments have shown that a 50 mm thick of soil covering is beneficial for the growth of potato plants and a 200 mm width of soil covering is beneficial for the growth of potato *** height of potato plants was 21 cm,and the natural emergence rate of potatoes was 95.8%on June 9,*** environment of soil covered could provide theoretical support for the mechanized pla

关键词： potato growth plastic mulching soil covered with film temperature distribution natural emergence rate

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Even Search in a Promising Region for Constrained Multi-Objective Optimization

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IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 474-486页

作者： Fei ming Wenyin Gong Yaochu Jin School of Computer Science China University of GeosciencesWuhan 430074China IEEE Faculty of Technology Bielefeld UniversityNorth Rhine-Westphalia 33619Germany School of Engineering Westlake UniversityHangzhou 310030China

In recent years, a large number of approaches to constrained multi-objective optimization problems(CMOPs) have been proposed, focusing on developing tweaked strategies and techniques for handling constraints. However, an overly finetuned strategy or technique might overfit some problem types,resulting in a lack of versatility. In this article, we propose a generic search strategy that performs an even search in a promising region. The promising region, determined by obtained feasible non-dominated solutions, possesses two general ***, the constrained Pareto front(CPF) is included in the promising region. Second, as the number of feasible solutions increases or the convergence performance(i.e., approximation to the CPF) of these solutions improves, the promising region shrinks. Then we develop a new strategy named even search,which utilizes the non-dominated solutions to accelerate convergence and escape from local optima, and the feasible solutions under a constraint relaxation condition to exploit and detect feasible regions. Finally, a diversity measure is adopted to make sure that the individuals in the population evenly cover the valuable areas in the promising region. Experimental results on 45 instances from four benchmark test suites and 14 real-world CMOPs have demonstrated that searching evenly in the promising region can achieve competitive performance and excellent versatility compared to 11 most state-of-the-art methods tailored for CMOPs.

关键词： Constrained multi-objective optimization even search evolutionary algorithms promising region real-world problems

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Investigation on UV-curing Reprocessable Thermosets Bearing Hindered Urea Bonds and Their Composites with Modified Zinc Oxide Nanoparticles

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Chinese Journal of Polymer Science 2024年第6期42卷 751-765页

作者： Jun-Hao Zhou Li-ming Tang Key Laboratory of Advanced Materials of Ministry of Education of China Department of Chemical EngineeringTsinghua UniversityBeijing100084China

In this study,a series of hindered urea bond(HUB)containing polyurethane-urea methacrylate prepolymers and a none HUB containing polyurethane methacrylate prepolymer were prepared using isobornyl methacrylate as the reactive diluent via one-pot *** prepolymers were characterized fully by various ***,their thermosets were fabricated via UV curing in presence of a photo initiator,and their mechanical property and thermal behavior were investigated and *** from the none HUB containing thermoset,the HUB containing thermosets(defined as PUT)could be recycled and reprocessed by hot press under relatively mild conditions with high recovery ratio of mechanical ***,zinc oxide(ZnO)nanoparticles were modified with 3-(trimethoxysilyl)propyl methacrylate and the modified ZnO(defined as ZnO-TPM)was dispersed and polymerized into PUT matrix to prepare their *** influence of ZnO-TPM on the mechanical performance of the composites was evaluated,which indicated that the Young’s modulus and tensile strength increased gradually to the maximum values at ZnO-TPM content of 1 wt%and then *** composites also displayed good reprocessability with improved recovery ratio compared to the pure PUT *** addition,the composite materials exhibited strong UV absorption capacity,implying their potential application in the circumstance where UV-shielding was required.

关键词： Polyurethane-urea methacrylate Hindered urea bond ZnO nanoparticles Reprocessing UV curing

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