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Fast multipole boundary element analysis of 2D viscoelastic composites with imperfect interfaces

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Science China(Technological Sciences) 2010年第8期53卷 2160-2171页

作者： ZHU XingYi CHEN WeiQiu huang zhiyi LIU YiJun Department of Civil Engineering Zhejiang UniversityZijingang CampusHangzhou 310058China Department of Engineering Mechanics Zhejiang UniversityYuquan CampusHangzhou 310027China Department of Mechanical Engineering University of CincinnatiCincinnatiOhio 45221-0072USA

A fast multipole boundary element method(FMBEM)is developed for the analysis of 2D linear viscoelastic composites with imperfect viscoelastic *** transformed fast multipole formulations are established using the time domain method. To simulate the viscoelastic behavior of imperfect interfaces that are frequently encountered in practice,the Kelvin type model is *** FMBEM is further improved by incorporating naturally the interaction among inclusions as well as eliminating the phenomenon of material *** all the integrals are evaluated analytically,high accuracy and fast convergence of the numerical scheme are *** numerical examples,including planar viscoelastic composites with a single inclusion or randomly distributed multi-inclusions are *** numerical results are compared with the developed analytical solutions,which illustrates that the proposed FMBEM is very efficient in determining the macroscopic viscoelastic behavior of the particle-reinforced composites with the presence of imperfect *** laboratory measurements of the mixture creep compliance of asphalt concrete are also compared with the prediction by the developed model.

关键词： boundary element method fast multipole method viscoelasticity imperfect interface multi-inclusion composite

Joint effects of micro-sized polystyrene and chlorpyrifos on zebrafish based on multiple endpoints and gut microbial effects

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Journal of Environmental Sciences 2023年第4期126卷 184-197页

作者： zhiyi huang Xiangxiang Xiao Dali Wang Yuheng Zhong Qi Ding Jing You Guangdong Key Laboratory of Environmental Pollution and Health Center for Environmental Microplastics StudiesSchool of EnvironmentJinan UniversityGuangzhou 511443China

Microplastics often co-occur with a variety of organic contaminants in aquatic environment and pose combined risks to aquatic wildlife. Here, we investigated joint effects of microsized polystyrene(mPS, 5 μm) and an organophosphate pesticide chlorpyrifos on zebrafish,using multiple endpoints at both fish individual and gut microbiota levels. It was revealed that mPS ingested by zebrafish accumulated in gut and liver, and caused oxidative stress, hyperactive swimming performance and histological damages in fish, and induced disorders and diversity alterations of the gut microbial community. More importantly, mPS exhibited considerable adsorption capacity against chlorpyrifos, and those adsorbing chlorpyrifos presented greater effects on fish individuals but no different effects on gut microbiota compared to single mPS exposure. Together with body residues of chlorpyrifos in zebrafish,it was proposed that the joint effects between mPS and chlorpyrifos were attributed to the chlorpyrifos released from mPS within zebrafish. The present results provided a comprehensive understanding of joint effects of mPS and contaminants co-occurring in the environment and emphasized the importance of considering the adsorbed chemicals in toxicological studies of microplastics.

关键词： Microplastics Polystyrene Joint effect Chlorpyrifos Zebrafish

Distributed sparse bundle adjustment algorithm based on three-dimensional point partition and asynchronous communication

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Frontiers of Information Technology & Electronic Engineering 2018年第7期19卷 889-904页

作者： Xiao-long SHEN Yong DOU Steven MILLS David M EYERS Huan FENG zhiyi huang College of Computer National University of Defense Technology Science and Technology on Parallel and Distributed Laboratory National University of Defense Technology Department of Computer Science University of Otago Department of Computer Science Tsinghua University

Sparse bundle adjustment(SBA) is a key but time-and memory-consuming step in three-dimensional(3 D) reconstruction. In this paper, we propose a 3 D point-based distributed SBA algorithm(DSBA) to improve the speed and scalability of SBA. The algorithm uses an asynchronously distributed sparse bundle adjustment(A-DSBA)to overlap data communication with equation computation. Compared with the synchronous DSBA mechanism(SDSBA), A-DSBA reduces the running time by 46%. The experimental results on several 3 D reconstruction datasets reveal that our distributed algorithm running on eight nodes is up to five times faster than that of the stand-alone parallel SBA. Furthermore, the speedup of the proposed algorithm(running on eight nodes with 48 cores) is up to41 times that of the serial SBA(running on a single node).

关键词： Sparse bundle adjustment Parallel Distributed sparse bundle adjustment Three-dimensional reconstruction Asynchronous

Enhanced Raman scattering of graphene on Ag nanoislands

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Science China(Physics,Mechanics & Astronomy) 2014年第11期57卷 2021-2023页

作者： HU Wei huang zhiyi ZHOU YingHui CAI WeiWei KANG JunYong Department of Physics Xiamen University

The effect of Ag nanoislands on the Raman of graphene was investigated in this *** with that on the bare silicon wafer,Raman enhancement was observed in the graphene film that covered on Ag/Si surface with nanoscale Ag islands,which would be induced by the localized plasmon resonance in Ag *** interaction between the graphene sheet and Ag/Si substrate was further *** peak shift and line shape of Raman spectroscopy indicated a nonuniform strain distribution in the Ag/Si supported graphene film.

关键词： graphene nanostructure Raman

Isotope effect of the phonons mean free path in graphene by micro-Raman measurement

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Science China(Physics,Mechanics & Astronomy) 2014年第10期57卷 1817-1821页

作者： ZHANG CanKun LI QiongYu TIAN Bo huang zhiyi LIN WeiYi LI HongYang HE DaHai ZHOU YingHui CAI WeiWei Department of Physics Laboratory of Nanoscale Condense Matter Physics Xiamen University Xiamen G-CVD Material Technology Co. Ltd

The isotope labeled graphene was synthesized in the concentration of 13 C carbon atom in 1%, 25%, 50%, 75% and 99%. The isotope effect on the phonon behavior in graphene was investigated based on the micro-Raman analysis of 13 C isotope labeled graphene samples. We found that the phonon scattering is affected by the isotopic carbon atom as a point defect. Based on the experiment results, the Klemens-Callaway model and uncertainty principle were used to obtain the mean free path of the G and D phonons. The results agree with the thermal conductivity measurement by non-contact optical method and with other theoretical calculations.

关键词： graphene isotope effect phonon mean free path

MATHEMATICAL　MODEL　AND　COMPUTER　SIMULATION　OF　MOISTURE　TRANSFER　PROCESS　DURING　SINTERING

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中国有色金属学会会刊：英文版 1995年第1期5卷 15-20页

作者： Zou zhiyi huang Tianzheng Yang Xiaosheng Chen Ji(Department of Mineral Engineering ,Central South University of Technology, Changsha 410083) CENT S UNIV TECHNOL DEPT MINERAL ENGNCHANGSHA 410083PEOPLES R CHINA

ＭＡＴＨＥＭＡＴＩＣＡＬＭＯＤＥＬＡＮＤＣＯＭＰＵＴＥＲＳＩＭＵＬＡＴＩＯＮＯＦ　ＭＯＩＳＴＵＲＥＴＲＡＮＳＦＥＲＰＲＯＣＥＳＳＤＵＲＩＮＧＳＩＮＴＥＲＩＮＧＺｏｕ；ＺｈｉｙｉＨｕａｎｇ；ＴｉａｎｚｈｅｎｇＹａｎｇ；... 详细信息

ＭＡＴＨＥＭＡＴＩＣＡＬＭＯＤＥＬＡＮＤＣＯＭＰＵＴＥＲＳＩＭＵＬＡＴＩＯＮＯＦ　ＭＯＩＳＴＵＲＥＴＲＡＮＳＦＥＲＰＲＯＣＥＳＳＤＵＲＩＮＧＳＩＮＴＥＲＩＮＧＺｏｕ；ＺｈｉｙｉＨｕａｎｇ；ＴｉａｎｚｈｅｎｇＹａｎｇ；ＸｉａｏｓｈｅｎｇＣｈｅｎ；Ｊｉ（...

关键词： mathematical model computer simulation sintering moisture transfer

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干湿冻融循环作用下沥青水老化的微观特性

建筑材料学报 2020年第4期23卷 920-926页

作者：张勤玲黄志义浙江大学建筑工程学院浙江杭州310058 塔里木大学水利与建筑工程学院新疆阿拉尔843300

模拟杭州夏季高温高湿、冬季微冻融的气候特点,在综合考虑循环次数、热、氧及水等因素的基础上,设计室内干湿冻融循环试验,采用薄膜烘箱对基质沥青和SBS改性沥青进行短期老化,借助红外光谱(FTIR)与凝胶渗透色谱(GPC)分析了干湿冻融循环... 详细信息

模拟杭州夏季高温高湿、冬季微冻融的气候特点,在综合考虑循环次数、热、氧及水等因素的基础上,设计室内干湿冻融循环试验,采用薄膜烘箱对基质沥青和SBS改性沥青进行短期老化,借助红外光谱(FTIR)与凝胶渗透色谱(GPC)分析了干湿冻融循环作用下沥青特征官能团和相对分子质量变化,探究沥青水老化的微观特性.结果表明:随着干湿冻融循环次数的增加,在热(60℃)氧化条件较为温和的情况下,基质沥青与SBS改性沥青中羰基的特征峰在FTIR图谱中变化较小,以至观测不到;亚砜基指数明显增大,丁二烯指数明显减小;数均相对分子质量、重均相对分子质量、分散度及大分子区(LMS)含量均逐渐增大.推荐采用亚砜基指数和LMS含量来定量表征沥青在干湿冻融循环作用下的水老化程度.FTIR与GPC试验均表明,在水环境中,干湿冻融循环作用将加剧沥青材料的老化;SBS改性沥青的抗水老化性能优于基质沥青.

关键词：沥青水老化干湿冻融循环作用微观特性

FTIR分峰拟合法定量分析沥青胶浆在含盐高温高湿环境中的结构变化

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材料导报 2020年第8期34卷 83-89页

作者：张勤玲黄志义浙江大学建筑工程学院杭州310058 塔里木大学水利与建筑工程学院阿拉尔843300

为研究南方滨海盐环境夏季高温高湿作用对沥青胶浆化学组分的影响,分析了基质沥青胶浆和SBS改性沥青胶浆在不同氯盐浓度(0%、5%、10%,质量分数)下的傅里叶变换红外光谱。深入分析了沥青胶浆光谱中1780~900 cm^-1波数段的吸收峰叠加带,... 详细信息

为研究南方滨海盐环境夏季高温高湿作用对沥青胶浆化学组分的影响,分析了基质沥青胶浆和SBS改性沥青胶浆在不同氯盐浓度(0%、5%、10%,质量分数)下的傅里叶变换红外光谱。深入分析了沥青胶浆光谱中1780~900 cm^-1波数段的吸收峰叠加带,基于二阶求导确定了叠加子峰个数和波数位置,采用Origin 2017软件对叠加带进行了曲线拟合分析。利用子峰面积与叠加带面积的比例间接表征了含盐高温高湿环境对沥青胶浆各化学组分的作用。曲线拟合结果显示:不同盐浓度环境中,基质沥青胶浆和SBS改性沥青胶浆的红外指标值呈现出一致的变化规律,即随着盐蚀干湿循环作用次数的增加,亚砜基官能团指数(IS=O)和芳香官能团指数(IAr)值均增大,脂肪支链指数(I B,a)、脂肪族官能团指数(IB)及丁二烯官能团指数(IC=C)值均减小;由于无机盐的“盐析”效应,在干湿循环作用下,盐分的存在加剧了沥青胶浆在水溶液中的老化;SBS改性沥青胶浆表现出更优异的抗盐老化性能。研究结果表明,傅里叶变换红外光谱技术结合曲线拟合分析方法能反映沥青胶浆在盐浓度与干湿循环耦合作用下内部化学组分变化,其为评价沥青胶浆在含盐高温高湿环境中的老化提供了有效依据。

关键词：道路工程盐环境高温高湿红外光谱老化特性

集料和纤维掺量对LTCC力学性能和微观结构的影响

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材料导报 2020年第18期34卷 18049-18055页

作者：陈文华黄志义浙江大学建筑工程学院杭州310058

为了优化轻质韧性水泥基复合材料(Lightweight toughness cement-based composites,LTCC),分别采用空心微珠和漂珠作为集料,添加亲水性聚乙烯醇(HPVA)纤维和聚丙烯(PP)纤维,共制备12组试件,探究集料和纤维掺量对LTCC的抗压和抗折强度、... 详细信息

为了优化轻质韧性水泥基复合材料(Lightweight toughness cement-based composites,LTCC),分别采用空心微珠和漂珠作为集料,添加亲水性聚乙烯醇(HPVA)纤维和聚丙烯(PP)纤维,共制备12组试件,探究集料和纤维掺量对LTCC的抗压和抗折强度、韧性、延性和毛细吸水特性的影响规律,并利用扫描电镜观察LTCC破坏后集料的微观形貌以及纤维的破坏形态。结果表明:当空心微珠掺量为20%和HPVA纤维体积掺量为1.5%时,LTCC的表观密度为1612 kg/m 3,抗压强度和抗折强度分别为60.06 MPa、20.55 MPa,且极限拉应变达到2.05%。空心微珠和漂珠能填充微小孔隙,从而细化LTCC内部孔隙,降低其毛细吸水能力。空心微珠具有更高的火山灰活性,促进水化反应生成高硅钙比的水化产物,改善集料与水泥基体间的界面过渡区,从而提高LTCC的弯曲韧性和拉伸延性。

关键词：轻质空心微珠漂珠弯曲韧性微观结构火山灰活性