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Effects of the initiation position on the damage and fracture characteristics of linear-charge blasting in rock

International Journal of Minerals,Metallurgy and Materials 2024年第3期31卷 443-451页

作者： Chenxi Ding Renshu yang Xiao Guo Zhe Sui Chenglong Xiao Liyun yang School of Civil and Resource Engineering University of Science and Technology BeijingBeijing 100083China School of Mechanics and Civil Engineering China University of Mining and Technology(Beijing)Beijing 100083China School of Mathematics and Physics University of Science and Technology BeijingBeijing 100083China State Key Lab of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China

To study the effects of the initiation position on the damage and fracture characteristics of linear-charge blasting, blasting model experiments were conducted in this study using computed tomography scanning and three-dimensional reconstruction methods. The fractal damage theory was used to quantify the crack distribution and damage degree of sandstone specimens after blasting. The results showed that regardless of an inverse or top initiation, due to compression deformation and sliding frictional resistance, the plugging medium of the borehole is effective. The energy of the explosive gas near the top of the borehole is consumed. This affects the effective crushing of rocks near the top of the borehole, where the extent of damage to Sections Ⅰ and Ⅱ is less than that of Sections Ⅲ and Ⅳ. In addition, the analysis revealed that under conditions of top initiation, the reflected tensile damage of the rock at the free face of the top of the borehole and the compression deformation of the plug and friction consume more blasting energy, resulting in lower blasting energy efficiency for top initiation. As a result, the overall damage degree of the specimens in the top-initiation group was significantly smaller than that in the inverse-initiation group. Under conditions of inverse initiation, the blasting energy efficiency is greater, causing the specimen to experience greater damage. Therefore, in the engineering practice of rock tunnel cut blasting, to utilize blasting energy effectively and enhance the effects of rock fragmentation, using the inverse-initiation method is recommended. In addition, in three-dimensional(3D) rock blasting, the bottom of the borehole has obvious end effects under the conditions of inverse initiation, and the crack distribution at the bottom of the borehole is trumpet-shaped. The occurrence of an end effect in the 3D linear-charge blasting model experiment is related to the initiation position and the blocking condition.

关键词： blasting linear charge initiation position computed tomography three-dimensional reconstruction damage

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Research progress on catalysts for organic sulfur hydrolysis: Review of activity and stability

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Chinese Journal of Chemical Engineering 2024年第7期71卷 203-216页

作者： Bingning Wang Xianzhe Wang Song yang Chao yang Huiling Fan Ju Shangguan State Key Laboratory of Clean and Efficient Coal Utilization Taiyuan University of TechnologyTaiyuan 030024China Shanxi Engineering Center of Civil Clean Fuel Taiyuan University of TechnologyTaiyuan 030024China College of Chemical Engineering and Technology Taiyuan University of TechnologyTaiyuan 030024China College of Environmental Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China

The removal of organic sulfur through catalytic hydrolysis is a significant area of research in the field of *** review provides an overview of recent advancements in catalytic hydrolysis technology of organic sulfur,including the activity,stability,and atmosphere effects of hydrolysis *** emphasis is on strategies for enhancing hydrolysis activity and anti-oxygen poisoning property of *** modification,metal doping and nitrogen doping have been found to improve the activity of *** components modification is the most commonly used method,the formation of oxygen vacancies through metal doping and creation of nitrogen basic sites through nitrogen doping also contribute to the hydrolysis of organic *** strategies for anti-oxygen poisoning are discussed in a systematic *** structural regulation of catalysts is beneficial for the desorption and diffusion of hydrogen sulfide(H_(2)S),thereby effectively inhibiting its *** doping and the addition of electronic promoters such as transition metals can protect active sites and decrease the number of active oxygen *** methods have been proven to enhance the anti-poisoning performance of ***,this article summarizes how different atmospheres affect the activity of hydrolysis *** objective of this review is to pave the way for the development of efficient,stable and widely used catalysts for organic sulfur hydrolysis.

关键词： Organic sulfur Hydrolysis Catalysts Activity Stability

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Piecewise Acoustic Source Imaging with Unknown Speed of Sound Using a Level-Set Method

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Communications on Applied Mathematics and Computation 2024年第2期6卷 1070-1095页

作者： Guanghui Huang Jianliang Qian yang yang Petroleum Geo-Services HoustonTX 77079USA Department of Mathematics Michigan State UniversityEast LansingMI 48824USA Department of Computational Mathematics Science and EngineeringMichigan State UniversityEastLansingMI48824USA

We investigate the following inverse problem:starting from the acoustic wave equation,reconstruct a piecewise constant passive acoustic source from a single boundary temporal measurement without knowing the speed of *** the amplitudes of the source are known a priori,we prove a unique determination result of the shape and propose a level set algorithm to reconstruct the *** the singularities of the source are known a priori,we show unique determination of the source amplitudes and propose a least-squares fitting algorithm to recover the source *** analysis bridges the low-frequency source inversion problem and the inverse problem of *** proposed algorithms are validated and quantitatively evaluated with numerical experiments in 2D and 3D.

关键词： Inverse gravimetry Acoustic source imaging Inversion of sound speed Level-set method Inverse problem

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Particle agglomeration and inhibition method in the fluidized pyrolysis reaction of waste resin

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Chinese Journal of Chemical Engineering 2024年第3期67卷 135-147页

作者： Congjing Ren Peng Zhang Qi Song Zhengliang Huang Yao yang Yongrong yang Ningbo Innovation Center Zhejiang UniversityNingbo 315100China College of Chemical and Biological Engineering Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture TechnologyZhejiang UniversityHangzhou 310027China

This work investigated the pyrolysis reaction of waste resin in a fluidized bed *** was found that the pyrolysis-generated ash would adhere to the surface of ceramic particles,causing particle agglomeration and *** kaolin could effectively inhibit the particle agglomeration during the fluidized pyrolysis reaction through physical isolation and chemical *** the one hand,kaolin could form a coating layer on the surface of ceramic particles to prevent the adhesion of organic ash generated by the pyrolysis of *** the other hand,when a sufficient amount of kaolin(-0.2%(mass))was added,the activated kaolin could fully contact with the Na+ ions generated by the pyrolysis of resin and react to form a high-melting aluminosilicate mineral(nepheline),which could reduce the formation of low-melting-point sodium sulfate and thereby avoid the agglomeration of ceramic particles.

关键词： Pyrolysis reaction of waste resin Fluidization Particle agglomeration Kaolin

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Effect of Vacancy Defects on the Properties of CoS_(2) and FeS_(2)

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Journal of Wuhan University of Technology(Materials Science) 2024年第3期39卷 627-638页

作者：冯中营 ZHANG Jianmin WANG Xiaowei yang Wenjin JING Yinlan yang Yan Department of Science Taiyuan Institute of TechnologyTaiyuan 030008China Computational Physics Research Center Taiyuan In-stitute of TechnologyTaiyuan 030008China College of Physics and Information Technology Shaanxi Normal UniversityXi’an 710119China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China Department of Physics College of ScienceNorth University of ChinaTaiyuan 030051China

In order to explore the effect of vacancy defects on the structural,electronic,magnetic and optical properties of CoS_(2) and FeS_(2),first-principles calculation method was used to investigate the *** calculated results of materials without vacancy are consistent with those reported in the literatures,while the results of materials with vacancy defect were different from those of literatures due to the difference vacancy *** Co vacancy defect hardly changes the half-metallic characteristic of CoS_(2).The Fe vacancy defect changes FeS_(2) from semiconductor to half-metal,and the bottom of the spin-down conduction band changes from the p orbital state of S to the d(t_(2g))orbital state of Fe,while the top of the valence band remains the d orbital d(eg)state of *** half-metallic Co vacancy defects of CoS_(2) and Fe vacancy defects of FeS_(2) are expected to be used in spintronic devices.S vacancy defects make both CoS_(2) and FeS_(2) *** the Co and S vacancy defects lead to the decrease of the magnetic moment of CoS_(2),while both the Fe and S vacancy defects lead to the obvious magnetic property of FeS_(2).Vacancy defects enhance the absorption coefficient of infrared band and long band of visible light obviously,and produce obvious red shift phenomenon,which is expected to be used in photoelectric devices.

关键词： cobalt disulfide iron disulfide vacancy defect fist principles

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Investigation on Strengthening Mechanism of China Low-Activation Ferrite Steel upon Thermo-Mechanical Treatment

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Acta Metallurgica Sinica(English Letters) 2024年第2期37卷 373-387页

作者： Dongtian yang Liangyin Xiong Hongbin Liao Guoping yang Xiaoyu Wang Shi Liu Institute of Metal Research Chinese Academy of SciencesShenyang110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang110016China Center for Fusion Science Southwestern Institute of PhysicsChengdu610041China

The objective of this study was to investigate the influence of strengthening mechanisms on the high-temperature mechanical properties of China low-activation ferrite(CLF-1)steel,which underwent thermodynamic design and thermo-mechanical treatment(TMT).The microstructure characterization in the normalized and tempered condition and the TMT condition was carried out using optical microscopy,X-ray diffractometer,and scanning electron microscopy with electron backscatter ***-resolution transmission electron microscopy was employed to determine the crystallographic structures of precipitated *** results indicated that the addition of Ti led to an increase in the allocation of C in MC phase and an enhancement in the content of MC *** to CLF-P steel in the normalized and tempered condition,a 1.5-fold increase in dislocation density and an order of magnitude improvement in MX phase density were achieved after *** formation of high-density nano-scale MC phases during TMT played a significant role in precipitation strengthening due to their favorable coherent relationship with the matrix and low interfacial free *** excellent high-temperature mechanical properties observed in CLF-P steel after TMT can be attributed to the combined effects of precipitation strengthening,dislocation strengthening,and lath strengthening.

关键词： China low-activation ferrite(CLF-1)steel Thermo-mechanical treatment MC phase Crystallographic structure Strengthening mechanism

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Synergistic strengthening mechanism of Ca^(2+)-sodium silicate to selective separation of feldspar and quartz

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International Journal of Minerals,Metallurgy and Materials 2024年第9期31卷 1985-1995页

作者： Bo Lin Jingzhong Kuang Yiqiang yang Zheyu Huang Delong yang Mingming Yu School of Resources and Environmental Engineering Jiangxi University of Science and TechnologyGanzhou 341000China Jiangxi Key Laboratory of Mining Engineering Ganzhou 341000China

Inhibitors are important for flotation separation of quartz and *** this study,a novel combined inhibitor was used to separate quartz and feldspar in near-neutral *** inhibition of the combined inhibitor was assessed by micro-flotation *** a series of detection methods were used to detect differences in the surface properties of feldspars and quartz after flotation reagents and put forward the synergistic strengthening *** outcomes were pointed out that pre-mixing combined inhibitors were more effective than the addition of Ca^(2+)and SS in sequence under the optimal proportion of 1:5.A concentrate from artificial mixed minerals that was characterized by a high quartz grade and a high recovery was acquired,and was found to be 90.70wt% and 83.70%,*** was demonstrated that the combined inhibitor selectively prevented the action of the collector and feldspar from Fourier-transform infrared(FT-IR)and adsorption capacity *** results of X-ray photoelectron spectroscopy(XPS)indicated that Ca^(2+)directly interacts with the surface of quartz to increase the adsorption of *** contrast,the chemistry property of Al on the feldspar surface was altered by combined inhibitor due to Na^(+)and Ca^(2+)taking the place of K^(+),resulting in the composite inhibitor forms a hydrophilic structure,which prevents the adsorption of the collector on the surface of feldspar by interacting with the Al active *** combination of Ca^(2+)and SS synergically strengthens the difference of collecting property between quartz and feldspar by collector,thus achieving the effect of efficient separation.A new strategy for flotation to separate quartz from feldspar in near-neutral pulp was provided.

关键词： feldspar quartz Ca^(2+)-sodium silicate selective adsorption flotation separation

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Extraction method of typical IEQ spatial distributions based on low-rank sparse representation and multi-step clustering

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Building Simulation 2024年第6期17卷 983-1006页

作者： Yuren yang yang Geng Hao Tang Mufeng Yuan Juan Yu Borong Lin School of Architecture Tsinghua UniversityBeijingChina Key Laboratory of Eco Planning&Green Building Ministry of EducationTsinghua UniversityBeijingChina

Indoor environment quality(IEQ)is one of the most concerned building performances during the operation *** non-uniform spatial distribution of various IEQ parameters in large-scale public buildings has been demonstrated to be an essential factor affecting occupant comfort and building energy ***,IEQ sensors have been widely employed in buildings to monitor thermal,visual,acoustic and air ***,there is a lack of effective methods for exploring the typical spatial distribution of indoor environmental quality parameters,which is crucial for assessing and controlling non-uniform indoor *** this study,a novel clustering method for extracting IEQ spatial distribution patterns is ***,representation vectors reflecting IEQ distributions in the concerned space are generated based on the low-rank sparse ***,a multi-step clustering method,which addressed the problems of the“curse of dimensionality”,is designed to obtain typical IEQ distribution patterns of the entire indoor *** proposed method was applied to the analysis of indoor thermal environment in Beijing Daxing international airport *** a result,four typical temperature spatial distribution patterns of the terminal were extracted from a four-month monitoring,which had been validated for their good *** typical patterns revealed typical environmental issues in the terminal,such as long-term localized overheating and temperature increases due to a sudden influx of *** extracted typical IEQ spatial distribution patterns could assist building operators in effectively assessing the uneven distribution of IEQ space under current environmental conditions,facilitating targeted environmental improvements,optimization of thermal comfort levels,and application of energy-saving measures.

关键词： indoor environment quality(IEQ) thermal environment spatial distribution temperature field low-rank sparse representation(LRSR) clustering

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High-entropy sulfurization enables efficient non-noble metal-based NiCoFeCuS electrocatalyst for alkaline oxygen evolution reaction

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PARTICUOLOGY 2024年第10期93卷 180-185页

作者： yang, Pan Sun, Mengxiang Wang, Jingchuan Li, Jinfeng yang, Ruizhu Hao, Yawei Qi, Li yang, Lijun Liu, Xue China Acad Engn Phys Inst Mat Jiangyou 621908 Peoples R China Yanshan Univ State Key Lab Metastable Mat Sci & Technol Qinhuangdao 066004 Peoples R China Sci & Technol Surface Phys & Chem Lab Jiangyou 621907 Peoples R China

Highly active and cost-effective oxygen evolution reaction electrocatalysts have become essential to replace commercial electrocatalysts that rely on rare noble metals. High-entropy sulfide nanomaterials, characterized by abundant randomly distributed elements and inherent stability, possess significant potential for applications. However, challenges such as uneven composition, partial oxidation, or imprecise synthesis control still remain in the materials preparation. Herein, a simple and effective two-step hydrothermal method was employed to synthesize NiCoFeCuS nanoparticles supported on foam nickel substrate. With the catalytic active sites produced by electron density redistribution in high-entropy and sulfurization, NiCoFeCuS exhibits excellent alkaline OER performance, with an overpotential of 261 mV and a Tafel slope of 57.97 mV dec(-1) at the current density of 10 mA cm(-2), which is only 88% of commercial RuO2 without any noble metals. (c) 2024 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

关键词： High-entropy Sulfurization NiCoFeCuS electrocatalyst Oxygen evolution reaction Overpotentials ALLOY NANOPARTICLES

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Stability and accuracy of central difference method for real-time dynamic substructure testing considering mass participation coefficient

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Earthquake Engineering and Engineering Vibration 2024年第3期23卷 625-636页

作者： Zheng Lichang Xu Guoshan yang Ge Wang Zhen yang Kaibo Zheng Zhenyun School of Civil Engineering Harbin Institute of TechnologyHarbin 150090China Key Lab of Structures Dynamic Behavior and Control Ministry of EducationHarbin Institute of TechnologyHarbin 150090China Key Lab of Intelligent Disaster Mitigation Ministry of Industry and Information TechnologyHarbin 150090China School of Civil Engineering and Architecture Wuhan University of TechnologyWuhan 430070China

For real-time dynamic substructure testing(RTDST),the influence of the inertia force of fluid specimens on the stability and accuracy of the integration algorithms has never been ***,this study proposes to investigate the stability and accuracy of the central difference method(CDM)for RTDST considering the specimen mass participation ***,the theory of the CDM for RTDST is ***,the stability and accuracy of the CDM for RTDST considering the specimen mass participation coefficient are ***,numerical simulations and experimental tests are conducted for verifying the effectiveness of the *** study indicates that the stability of the algorithm is affected by the mass participation coefficient of the specimen,and the stability limit first increases and then decreases as the mass participation coefficient *** most cases,the mass participation coefficient will increase the stability limit of the algorithm,but in specific circumstances,the algorithm may lose its *** stability and accuracy of the CDM considering the mass participation coefficient are verified by numerical simulations and experimental tests on a three-story frame structure with a tuned liquid damper.

关键词： real-time dynamic substructure testing central difference method stability mass participation coefficient tuned liquid damper

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