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A time−space porosity computational model for concrete under sulfate attack

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Frontiers of Structural and Civil Engineering 2023年第10期17卷 1571-1584页

作者： hui song Jiankang CHEN Jiangxi Provincial Key Laboratory of Hydraulic&Civil Engineering Infrastructure Security Nanchang Institute of TechnologyNanchang 330099China Zhejiang Provincial Engineering Research Center for the Safety of Pressure Vessel and Pipeline Ningbo UniversityNingbo 315211China Ningbo University Donghai Academy Ningbo 315211China

The deterioration of the microscopic pore structure of concrete under external sulfate attack(ESA)is a primary cause of ***,little effort has been invested in exploring the temporal and spatial development of the porosity of concrete under *** study proposes a mechanical–chemical model to simulate the spatiotemporal distribution of the porosity.A relationship between the corrosion damage and amount of ettringite is proposed based on the theory of volume *** addition,the expansion strain at the macro-scale is obtained using a stress analysis model of composite concentric sphere elements and the micromechanical mean-field ***,considering the influence of corrosion damage and cement hydration on the diffusion of sulfate ions,the expansion deformation and porosity space−time distribution are obtained using the finite difference *** results demonstrate that the expansion strains calculated using the suggested model agree well with previously reported experimental ***,the tricalcium aluminate concentration,initial elastic modulus of cement paste,corrosion damage,and continuous hydration of cement significantly affect concrete under *** proposed model can forecast and assess the porosity of concrete covers and provide a credible approach for determining the residual life of concrete structures under ESA.

关键词： expansion deformation porosity internal expansion stress external sulfate attack mechanical–chemical coupling model

Study on effectiveness evaluation of weapon systems based on grey relational analysis and TOPSIS

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Journal of Systems Engineering and Electronics 2009年第1期20卷 106-111页

作者： Gu hui song Bifeng Coll. of Aeronautics Northwestern Polytechnical Univ. Xi'an 710072 P. R. China

To evaluate the effectiveness of weapon systems, the advantages and disadvantages of grey relational analysis and TOPSIS for multiattribute decision-making is pointed out, and an effectiveness evaluation model of weapon systems by combining grey relational analysis and TOPSIS is proposed. The model aggregates the grey relational grade and the distance to a new integrated closeness and reflects not only the trend but also the situation of the alternative. The example illuminates that the model is effective for the effectiveness evaluation of weapon systems.

关键词： multiattribute decision-making effectiveness evaluation grey relational analysis TOPSIS integratedcloseness.

Case Study of a Short-Term Wave Energy Forecasting Scheme:North Indian Ocean

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Journal of Ocean University of China 2021年第3期20卷 463-477页

作者： ZHENG Chongwei song hui Dalian Naval Academy Dalian 116018China State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physicsthe Chinese Academy of SciencesBeijing 100029China Shandong Provincial Key Laboratory of Ocean Engineering Ocean University of ChinaQingdao 266100China

Short-term forecasts of wave energy play a key role in the daily operation,maintenance planning,and electrical grid operation of power *** this study,we propose a short-term wave energy forecast scheme and use the North Indian Ocean(NIO)as a case *** with the traditional forecast scheme,our proposed scheme considers more forecast *** addition to the traditional short-term forecast factors related to wave energy(wave power,significant wave height(SWH),wave period),our scheme emphasizes the forecast of a series of key factors that are closely related to the effectiveness of the energy output,capture efficiency,and conversion *** factors include the available rate,total storage,effective storage,co-occurrence of wave power-wave direction,co-occurrence of the SWH-wave period,and the wave energy at key *** the regional nesting of nu-merical simulations of wave energy in the NIO,the selection of the southern boundary is found to have a significant impact on the simulation precision,especially during periods of strong swell processes of the South Indian Ocean(SIO)*** tropical cyclone‘VARDAH’in the NIO,as compared with the simulation precision obtained with no expansion of the southern boundary(scheme-1),when the southern boundary is extended to the tropical SIO(scheme-2),the improvement in simulation precision is significant,with an obvious increase in the correlation coefficient and decrease in *** addition,the improvement is much more significant when the southern boundary extends to the SIO westerly(scheme-3).In the case of strong swell processes generated by the SIO westerly,the improvement obtained by scheme-3 is even more significant.

关键词： wave energy short-term forecast regional nesting boundary condition

Compressed sensing method for human activity recognition using tri-axis accelerometer on mobile phone

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The Journal of China Universities of Posts and Telecommunications 2017年第2期24卷 31-37,71页

作者： song hui Wang Zhongmin School of Computer Science and Technology Xi'an University of Posts and Telecommunications

The diversity in the phone placements of different mobile users＇ dailylife increases the difficulty of recognizing human activities by using mobile phone accelerometer data. To solve this problem, a compressed sensing method to recognize human activities that is based on compressed sensing theory and utilizes both raw mobile phone accelerometer data and phone placement information is proposed. First, an over-complete dictionary matrix is constructed using sufficient raw tri-axis acceleration data labeled with phone placement information. Then, the sparse coefficient is evaluated for the samples that need to be tested by resolving L1 minimization. Finally, residual values are calculated and the minimum value is selected as the indicator to obtain the recognition results. Experimental results show that this method can achieve a recognition accuracy reaching 89.86%, which is higher than that of a recognition method that does not adopt the phone placement information for the recognition process. The recognition accuracy of the proposed method is effective and satisfactory.

关键词： activity recognition compressed sensing mobile phone accelerometer phone placements

EFFECT OF DAMAGE EVOLUTION ON POISSON'S RATIO OF CONCRETE UNDER SULFATE ATTACK

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Acta Mechanica Solida Sinica 2011年第3期24卷 209-215页

作者： hui song Jiankang Chen The Faculty of Mechanical Engineering and Mechanics Ningbo University Ningbo 315211 China State Key Laboratory of Turbulence and Complex Systems Peking University Beijing 100871 China

Experimental results about concrete under sulfate attack are summarized, which include the variation of mass density of samples and velocity of ultrasonic wave propagating in samples. The evolution damage is analyzed in terms of the experimental results, and close attention is paid to the effect of damage evolution on Poisson＇s ratio. This study shows that Poisson＇s ratio is significantly affected by the concentration of solution and water-cement ratio. Poisson＇s ratio of concrete changes very little when the water-cement ratio is selected as 0.6 or 0.8, so that such change may be neglected. If water-cement is 0.4, however, the Poisson＇s ratio of the sample significantly changes. When the concrete sample of 0.4 water-cement ratio is immersed in sodium sulfate solution of 8% concentration for 285 days, Poisson＇s ratio increase 10.14% compared with its initial value. There exist a sensitive region and a non-sensitive region for the change rate of Poisson＇s ratio with respect to corrosion time. The change rate of Poisson＇s ratio monotonously decreases with corrosion time in the sensitive region; in the non-sensitive region, the change rate of Poisson＇s ratio is almost equal to zero.

关键词： concrete sulfate attack porosity Poisson's ratio damage evolution

An Internal Expansive Stress Model of Concrete under Sulfate Attack

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Acta Mechanica Solida Sinica 2016年第6期29卷 610-619页

作者： hui song Jiankang Chen Jinyang Jiang The Faculty of Mechanical Engineering and Mechanics Ningbo University Ningbo 315211 China State Key Laboratory of Turbulence and Complex Systems Peking University Beijing 100871 China The Faculty of Civil Engineering and Architecture Nanchang Institute of Technology Nanchang 300029 China School of Materials Science and Engineering Southeast University Nanjing 211189 China

Concrete experiences expansive deformation during sulfate attack due to internal expansive stress. Sulfate ions enter concrete pores, react with the pore solution, and produce ettringite. The production of ettringite explains the internal expansive stress that reduces the durability of concrete. In this study, the model of internal expansive stress was achieved through the Eshelby＇s theory, as well as the experimental results for concrete erosion. Numerical simulation indicated that internal expansive stress is not only determined by the water-to-cement ratio of concrete and the concentration of sulfate solution, but also affected by the relaxation time of concrete.

关键词： concrete viscous internal stress model erosion micromechanics

Experimental and Theoretical Analyses on the Density and Modulus Development of Concrete Under Continued Hydration

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Acta Mechanica Solida Sinica 2018年第2期31卷 161-173页

作者： Lanzhen Yu Jiankang Chen hui song The Faculty of Mechanical Engineering and Mechanics Ningbo University Ningbo 315211 China State Key Laboratory of Turbulence and Complex Systems Peking University Beijing 100871 China Department of Architectural Engineering Ningbo Polytechnic Ningbo 315800 China

In this paper, new models of the density and modulus development of concrete under continued hydration were studied. Experimental study was performed for different mixes of concrete. To avoid considering the effect of variation of Poisson＇s ratio, the one-dimensional ultrasonic technique was adopted to detect the modulus development of concrete under continued hydration. The experimental results indicate the nonlinear characteristics of density and modulus evolution. At the initial stage of continued hydration, the density and modulus increase quickly, and then the increases slow down and finally tend to be constant. The mechanism of modulus enhancement is that the newly produced C-S-H gel in the continued hydration process not only leads to the decrease in porosity, but also repairs the initial defects of concrete. Based on this mechanism, simple differential equations for the density and modulus development of concrete were established by considering the chemical reactions of continued hydration, and new simple models for density and modulus development were proposed.

关键词： Concrete Continued hydration Density development Modulus development Ultrasonic

基于SBM-DEA模型的江苏省碳排放效率研究

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国土与自然资源研究 2025年第1期 44-49页

作者：朱凡凡宋辉冯欢盐城工学院经济管理学院江苏盐城224051

本文运用MaxDEA9软件,基于非期望产出的SBM-DEA模型和Malmquist指数法从静态和动态两个方面研究2010-2021年江苏省及其13个地级市的碳排放效率。结果表明,(1)江苏省的整体碳排放效率在2010-2021年间稳步增长,并且在2019年开始达到有效,... 详细信息

本文运用MaxDEA9软件,基于非期望产出的SBM-DEA模型和Malmquist指数法从静态和动态两个方面研究2010-2021年江苏省及其13个地级市的碳排放效率。结果表明,(1)江苏省的整体碳排放效率在2010-2021年间稳步增长,并且在2019年开始达到有效,在空间上呈现苏北大于苏南大于苏中的不均匀分布格局。(2)江苏省碳排放效率的平均增长速度呈现苏北大于苏中大于苏南的趋势。(3)江苏省及其13个地级市技术变化指数变动对碳排放效率增长有关键作用,碳排放效率各期增长速度受到当期技术发展水平的制约。

关键词： “双碳”目标碳排放效率 SBM-DEA模型资源配置

Genome-wide analysis of nucleotide-binding site disease resistance genes in Medicago truncatula

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Chinese Science Bulletin 2014年第11期59卷 1129-1138页

作者： hui song Zhibiao Nan Key Laboratory of Grassland Agro-Ecosystems of Ministry of Agriculture College of Pastoral Agriculture Science and TechnologyLanzhou University

The class of nucleotide-binding site(NBS)-Leucine-rich repeat(LRR) disease resistance genes play an important role in defending plants from a variety of pathogens and insect pests. Consequently, many NBS-LRR genes have been identified in various plant species. In this study, we identified 617 NBS-encoding genes in the Medicago truncatula genome(Mt3.5v5) and divided them into two groups, regular(490) and non-regular(127) NBSLRR genes. The regular NBS-LRR genes were characterized on the bases of structural diversity, chromosomal location, gene duplication, conserved protein motifs, and EST expression profiling. According to N-terminal motifs and LRR motifs, the 490 regular NBS-LRR genes were then classified into 10 types: CC-NBS(4), CC-NBS-LRR(212), TIR-NBS(20), TIR-NBS-LRR(160), TIR-NBS-TIR(1), TIR-NBS-TIR-LRR(2), NBS-TIR(7), NBS-TIR-LRR(1), NBS(10), and NBS-LRR(73). Analysis of the physical location and duplications of the regular NBS-LRR genes revealed that the M. truncatula genome is similar to rice. Interestingly, we found that TIR-type genes are more frequently expressed than non-TIR-type genes in M. truncatula, whereas the number of non-TIR-type regular NBSLRR genes was greater than TIR-type genes, suggesting the gene expression was not associated with the total number of NBS-LRR genes. Moreover, we found that the phylogenetic tree supported our division of the regular NBS-LRR genes into two distinct clades(TIR-type and non-TIR-type), but some of the non-TIR-type lineages contain TIR-type genes. These analyses provide a robust database of NBS-LRR genes in M. truncatula that will facilitate the isolation of new resistance genes and breeding strategies to engineer disease resistance in leguminous crop.

关键词：核苷酸结合位点基因组分析抗病基因苜蓿富含亮氨酸重复序列保守结构域 R基因染色体定位