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Journal of Wuhan University of Technology(materials Science) 2025年第1期40卷 194-203页

作者： WANG Zhen LI Huajian HUANG Fali YANG Zhiqiang WEN Jiaxin SHI Henan Railway Engineering Research Institute China Academy of Railway Science Corporation LimitedBeijing 100081China State key laboratory for Track Technology of High-Speed Railway Beijing 100081China

In order to achieve the large-scale application of manufactured sand in railway high-strength concrete structure,a series of high-strength manufactured sand concrete(HMC)are prepared by taking the manufactured sand lithology(tuff,limestone,basalt,granite),stone powder content(0,5%,10%,15%)and concrete strength grade(C60,C80,C100)as *** evolution of mechanical properties of HMC and the correlation between cubic compressive strength and other mechanical properties are *** to river sand,manufactured sand enhances the cubic compressive strength,axial compressive strength and elastic modulus of concrete,while its potential microcracks weaken the flexural strength and splitting tensile strength of *** powder content displays both positive and negative effects on mechanical properties of HMC,and the stone powder content is suggested to be less than 10%.The empirical formulas between cubic compressive strength and other mechanical properties are proposed.

关键词： manufactured sand concrete railway mechanical property lithology stone powder content

Application of Image Analysis Based on SEM and Chemical Mapping on PC Mortars under Sulfate Attack

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Journal of Wuhan University of Technology(materials Science) 2014年第3期29卷 534-539页

作者：于诚孙伟 Scrivener Karen School of materials Science and Engineering Southeast University jiangsu key Lab of construction Material laboratory of construction materials Swiss Federal Institute of Technology (EPFL)Ecublens 1015 LausanneSwitzerland

The degradation mechanisms of cementitious materials exposed to sulfate solutions have been controversial, despite considerable research. In this paper, two methodologies of image analysis based on scanning electron microscope and chemical mapping are used to analyse Portland cement mortars exposed to sodium sulfate solution. The effects of sulfate concentration in solution and water to cement ratio of mortar, which are considered as the most sensitive factors to sulfate attack, are investigated respectively by comparing the macro expansion with microstructure analysis. It is found that the sulfate concentration in pore solution, expressed as sulfate content in C-S-H, plays a critical role on the supersaturation with respect to ettringite and so on the expansion force generated.

关键词： image analysis mapping sulfate attack pore solution

Loss Aware Feature Attention Mechanism for Class and Feature Imbalance Issue

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Computers, materials & Continua 2025年第1期82卷 751-775页

作者： Yuewei Wu Ruiling Fu Tongtong Xing Fulian Yin College of Information and Communication Engineering Communication University of ChinaBeijing100024China State key laboratory of Media Convergence and Communication Communication University of ChinaBeijing100024China

In the Internet era,recommendation systems play a crucial role in helping users find relevant information from large *** imbalance is known to severely affect data quality,and therefore reduce the performance of recommendation *** to the imbalance,machine learning algorithms tend to classify inputs into the positive(majority)class every time to achieve high prediction *** can be categorized such as by features and classes,but most studies consider only class *** this paper,we propose a recommendation system that can integrate multiple networks to adapt to a large number of imbalanced features and can deal with highly skewed and imbalanced datasets through a loss *** propose a loss aware feature attention mechanism(LAFAM)to solve the issue of feature *** network incorporates an attention mechanism and uses multiple sub-networks to classify and learn *** better results,the network can learn the weights of sub-networks and assign higher weights to important *** propose suppression loss to address class imbalance,which favors negative loss by penalizing positive loss,and pays more attention to sample points near the decision *** on two large-scale datasets verify that the performance of the proposed system is greatly improved compared to baseline methods.

关键词： Imbalanced data deep learning e-commerce recommendation loss function big data analysis

Simulation of the Cracking and Ablation Behavior of Ferrosiliceous and Siliceous Nuclear Sacrificial Concretes

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Journal of Wuhan University of Technology(materials Science) 2016年第5期31卷 982-988页

作者：蒋金洋 YU Yingjun CHU Hongyan SUN Wei GAO Yun SHE Wei School of materials Science and Engineering Southeast UniversityNanjing 211189China jiangsu key laboratory of construction materials Southeast UniversityNanjing 211189China

We investigated the simulation of the cracking and ablation behavior of ferro-siliceous and siliceous nuclear sacrificial concretes. To this end, four type of sacrificial concretes were fabricated, i e, the ferro-siliceous（F） and siliceous（S） plain concretes, and the polypropylene fiber reinforced concretes of the above two（FF, SF）. The cracking and ablation behaviors of the sacrificial concretes were investigated by simulation tests, and the simulated elevated temperature was obtained by means of thermite powder. The number and the width of the cracks were compared and the pore size distribution of sacrificial concretes was measured. In addition, the interface and chemical composition of melt at different positions were analyzed, and the ablation depth of the sacrificial concrete crucibles was also measured. It was found that the siliceous concrete shows to be more prone to cracking than the ferro-siliceous concrete due to the higher content of fly ash and lower water to binder ratio; though the ablation depth of siliceous concrete is found to be slightly larger, no clear difference can be detected for the basemat ablation rate.

关键词： sacrificial concrete cracking ablation MCCI high temperature

Water Absorption and Chloride Ion Penetrability of Concrete Damaged by Freeze-thawing and Loading

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Journal of Wuhan University of Technology(materials Science) 2017年第2期32卷 330-337页

作者：杨林 SUN Wei LIU Cheng 张云升 LIANG Fei jiangsu key laboratory for construction materials Southeast University Nanjing 211189 China School of materials Science & Engineering Southeast University Nanjing 211189 China

In order to investigate water and chloride ion transport in damaged concrete, three types of concrete were prepared, freeze-thawing（F-T） cycling and compressive loading were adopted to induce damage to concrete. Ultrasonic pulse velocity technique was used for evaluating the damage degree of concrete, and the defects of damaged concrete were also detected by X-CT. Water absorption and chloride ion penetrability were used for describing the transport properties of damaged concrete. Effects of damage degree on the water absorption rate and chloride ion penetrability were investigated in detail and the relationships were also established. The results show that the water absorption of concrete makes various responses to damage degree due to the difference of concrete type and damage method. For same concrete with similar damage degree, the water absorption rate of F-T damaged concrete is usually larger than that of concrete damaged by loading. The chloride ion penetrability of damaged concrete increases linearly with increasing damage degree, which is more sensitive to damage degree if the original penetrability of sound concrete is higher.

关键词： concrete water absorption chloride ion freeze-thawing loading durability

Dynamic Compression Behavior of Ultra-high Performance Cement-based Composite with Hybrid Steel Fiber Reinforcements

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Journal of Wuhan University of Technology(materials Science) 2020年第5期35卷 900-907页

作者： RONG Zhidan WANG Yali WU Shenping School of materials Science and Engineering Southeast UniversityNanjing 211189China jiangsu key laboratory of construction materials Southeast UniversityNanjing 21189China

Ultra-high performance cement-based composites (UHPCC) is promising in construction of concrete structures that suffer impact and explosive *** this study,a reference UHPCC mixture with no fiber reinforcement and four mixtures with a single type of fiber reinforcement or hybrid fiber reinforcements of straight smooth and end hook type of steel fibers were *** Hopkinson pressure bar (SHPB) was performed to investigate the dynamic compression behavior of UHPCC and X-CT test and 3D reconstruction technology were used to indicate the failure process of UHPCC under impact *** show that UHPCC with 1% straight smooth fiber and 2% end hook fiber reinforcements demonstrated the best static and dynamic mechanical *** the hybrid steel fiber reinforcements are added in the concrete,it may need more impact energy to break the matrix and to pull out the fiber reinforcements,thus,the mixture with hybrid steel fiber reinforcements demonstrates excellent dynamic compressive performance.

关键词： ultra-high performance cement-based composite dynamic compression behavior hybrid fiber reinforcements split Hopkinson pressure bar

construction of plum-branch-like CoSe2@N-Doped carbon/carbon fiber with dual protective mechanisms for enhanced lithium storage

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Progress in Natural Science:materials International 2024年第3期34卷 495-502页

作者： Ying Wang Ming Zhang Lei Chen Yanjuan Li Qingqing Wang Xiaobin Wu Lingdi Shen Xiao Yan School of Chemistry & materials Science Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional Materials Jiangsu Normal University

Cobalt selenide（CoSe2） emerges as a highly promising anode material for lithium-ion batteries（LIBs） owing to its high theoretical capacity and cost-effectiveness. Despite these merits, its practical utilization faces challenges stemming from substantial volume fluctuations and limited electronic conductivity. To tackle these issues, a plumbranch-like structure of CoSe2@N-doped carbon that embedded in one-dimensional N-doped carbon fibers（CoSe2@NC/CFs）, is successfully synthesized through an in-situ confinement method. Well-defined CoSe2@NC nanoparticles, featuring diameters between 20～30 nm, are uniformly dispersed on both the inner and outer surfaces of the carbon fibers. The distinctive architecture of CoSe2@NC/CFs ensures an increased number of active sites, elevated electronic conductivity, alleviated volume expansion, and accelerated reaction ***, the CoSe2@NC/CFs exhibits remarkable cycling performance and exceptional rate *** at a current density of 1000 mA g-1, the CoSe2@NC/CFs anode sustains a capacity of 664 mA h g-1with no obvious capacity decay over 500 cycles. Even at a high current density of 5000 mA g-1, it maintains a capacity of 445 mA h g-1with a mere 0.02 % capacity decay per cycle. This study introduces a novel approach to anode material design, showcasing significant advancements in lithium-ion battery technology.

关键词： Carbon fiber Electrochemical performances Electrode Lithium-ion battery Metal-selenide

Living concrete with self-healing function on cracks attributed to inclusion of microorganisms: Theory, technology and engineering applications——A review

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Science China(Technological Sciences) 2021年第10期64卷 2067-2083页

作者： QIAN ChunXiang ZHENG TianWen RUI YaFeng School of materials Science and Engineering Southeast UniversityNanjing 211189China Research Center of Green Building&construction materials Southeast UniversityNanjing 211189China key Lab of Microbial Bio-mineralization Technology China Construction Materials IndustryNanjing 211189China jiangsu key laboratory for construction materials Southeast UniversityNanjing 211189China

Concrete is the most widely used composite material in civil *** induced calcium carbonate precipitation(MICP)is a green and environmental friendly technology,which has received extensive attention in repair of concrete *** paper introduces the research progress in Southeast University research in past 16 *** the early stage,MICP technology of urea hydrolyzed by Bacillus pasteurii was mainly investigated to repair the surface cracks and to fill large-size cracks with ***,aiming at the hidden cracks that were difficult for human intervention,a new mineralization route of Bacillus mucilaginosus was proposed,which could repair faster than Bacillus alcalophilus,and the problem of ammonia emission in the repair process of Bacillus pasteurii was also *** addition,in order to improve the protection of bacteria and the self-healing efficiency of the later age cracks,the methods of fiber immobilization,carrier uniformly immobilization and core-shell structural immobilization had been compared and *** results showed that core-shell structural immobilization had good protection ability and strong ***’s more,the paper also summarized the characteristics of spore germination,cell activity,nucleation and biological calcium carbonate in crack zone,and introduced the application experience of microbial self-healing concrete in water conservancy projects and subway stations.

关键词： living concrete self-healing crack microorganisms engineering application

Methods of Modifying the Brittle Behavior of Cementitious Composites

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Journal of Wuhan University of Technology(materials Science) 2010年第1期25卷 156-161页

作者：庞超明 LEUNG Christopher KY College of materials Science and Engineering Southeast UniversityJiangsu Key laboratory of Construction Materials Department of Civil and Environmental Engineering Hong Kong University of Science and Technology

We put forward effective methods of increasing the tensile strain of cementitious composites with 2% PVA fiber and high fly ash content. The test results show that curing condition has a significantly effect on the tensile performance. It is approved that the specimens incorporated appropriate volume fraction rubber powder and lightweight aggregate greatly increase the tensile strain of composites at medium-term age, but indefinitely at long-term age. To a certain extent, EVA can limitedly enhance the tensile performance of comentitious composites owing to the formation of polymer membrane and the hindered hydration of cement.

关键词： high-ductility cementitious composites (HDCC) tensile properties high content of fly ash rubber powder light aggregate ethylene vinyl alcohol latex powder

Stabilization Mechanism of Calcium Lignosulphonate Used in Expansion Sensitive Soil

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Journal of Wuhan University of Technology(materials Science) 2020年第5期35卷 847-855页

作者： WU Dajiang SHE Weil WEI Luansu ZUO Wenqiang' HU Xiangyu HONG Jinxiang MIAO Changwen jiangsu key laboratory for construction materials Southeast UniversityNanjing 211189China Sobute New materials Co.Lld Nanjing 211103.China

A series of tests were performed to investigate the macroscopic properties and the stabilization mechanism of calcium lignosulphonate modified expansive *** with natural soil,soil modified by 4%calcium lignosulphonate showed 56.5%increased 28 days unconfined compressive strength and 23.8%decreased free expansion *** X-ray diffraction analysis results indicate the existence of cation exchange and the reduction of montmorillonite interplanar *** X-computed tomography results demonstrate that calcium lignosulphonate decreased the porosity and optimized the pore *** calcium lignosulphonate also increased the stability of the suspension system according to the Zeta potential ***,the results of rheological tests show that the moderate amount of calcium lignosulphonate enhanced the yield stress and the plastic viscosity,proving the formation of a strong connection between soil particles.

关键词： calcium lignosulphonate expansive soil mechanical characteristic stabilization mechanism