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Mechanical Properties of Soil-Rock Mixture Filling in Fault Zone Based on mesostructure

Computer Modeling in Engineering & Sciences 2022年第8期132卷 681-705页

作者： Mei Tao Qingwen Ren Hanbing Bian Maosen Cao Yun Jia Department of Engineering Mechanics Hohai UniversityNanjing210098China Laboratoire de Genie Civil et g´eo-Environnement Universite de LilleLille59000France Laboratoire de Mecanique MultiphysiqueMulti-´echelleUniversite de LilleLille59000France

Soil-rock mixture(SRM)filling in fault zone is an inhomogeneous geomaterial,which is composed of soil and rock block.It controls the deformation and stability of the abutment and dam foundation,and threatens the long-term safety of high arch dams.To study the macroscopic and mesoscopic mechanical properties of SRM,the development of a viable mesoscopic numerical simulation method with a mesoscopic model generation technology,and a reasonable parametric model is crucially desired to overcome the limitations of experimental conditions,specimen dimensions,and experiment fund.To this end,this study presents a mesoscopic numerical method for simulating the mechanical behavior of SRM by proposing mesoscopic model generation technology based on its mesostructure features,and a rock parameter model considering size effect.The validity and rationality of the presented mesoscopic numerical method is experimentally verified by the triaxial compression tests with different rock block contents(RBC).The results indicate that the rock block can increase the strength of SRM,and it is proved that the random generation technique and the rock parameter model considering size effect are validated.Furthermore,there are multiple failure surfaces for inhomogeneous geomaterial of SRM,and the angle of the failure zone is no longer 45◦.The yielding zones of the specimen are more likely to occur in thin sections of soil matrix isolated by blocks with the failure path avoiding the rock block.The proposed numerical method is effective to investigate the meso-damage mechanism of SRM.

关键词： Soil-rock mixture(SRM) triaxial compression tests random generation technique mesostructure rock parameter model size effect finite element method

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Electrical resistivity change of saturated sand during reliquefaction under hammering loading

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Earthquake Engineering and Engineering Vibration 2023年第3期22卷 613-622页

作者： Wang Binghui Xiao Xing Zhang Lei Wang Liyan Jin Dandan Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering MechanicsChina Earthquake AdministrationHarbin 150080China School of Civil Engineering and Architecture Jiangsu University of Science and TechnologyZhenjiang 212000China Institute of Geotechnical Engineering Nanjing Tech UniversityNanjing 210000China Faculty of Civil Engineering and Mechanics Jiangsu UniversityZhenjiang 212013China

The electrical resistivity method was verified as an optional technique to monitor the change of mesostructure of saturated soils.To investigate the change laws of resistivity and analyze the reliquefaction meso-mechanism during the consecutive liquefaction process,five successive impact liquefaction tests were performed in a one-dimensional cubical chamber.The resistivity variation and excess pore water pressure(EPWP)were measured.The results indicate that the excess pore water pressure experienced four stages:quick increase stage,slow dissipation stage,rapid dissipation stage,and stability stage.Meanwhile,a swift decrease of resistivity emerged before the start of the rapid dissipation stage of EPWP,and then an increasing trend of resistivity is demonstrated with the densification of soil.It is proved that the vertical pore connectivity of liquefied sand is better than its random deposit state,based on a comparative study of porosity calculated from the settlement and resistivity of sand after each test.

关键词： sand reliquefaction resistivity excess pore water pressure mesostructure

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Flexibility in DUT-8(Cu)Metal-Organic Framework:Impact of Cluster,Stress,History,and Hierarchical Texture

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CCS Chemistry 2023年第10期5卷 2225-2236页

作者： Mariia Maliuta Irena Senkovska Vitaliy Romaka Mariia Roslova Zhehao Huang Petko Petkov Volodymyr Bon Stefan Kaskel Chair of Inorganic Chemistry I Technische Universität DresdenD-01069 Dresden Leibniz Institute for Solid State Research(IFW Dresden) 01069 Dresden Department of Materials and Environmental Chemistry Stockholm UniversitySE-10691 Stockholm Faculty of Chemistry and Pharmacy Department of Organic Chemistry and PharmacognosySofia University“St.Kl.Ohridski”1164 Sofia

The flexibility of metal-organic frameworks(MOFs)featuring stimuli-responsive structural transitions is often governed not only by the chemical composition and topology but also by orthogonal factors such as particle size,desolvation method,and history of the sample.A precise understanding of the mechanism behind such observations has been lacking up to now,and there are still substantial open questions concerning the impact of sample treatment history.The DUT-8(M)family([M_(2)(2,6-ndc)2(dabco)]n,2,6-ndc=2,6-naphthalene dicarboxylate,dabco=1,4-diazabicyclo-[2.2.2]-octane),encompasses isostructural compounds based on Ni,Zn,Co,and Cu in the cluster node and is representative of pillared layer MOFs,often showing flexible behavior.In this contribution,we discuss a possible explanation for the differences in flexibility observed in desolvated phases of DUT-8(Cu).Theoretical calculations and crystallographic data shed light on the preferred formation of interpenetrated confined closed pore phases in DUT-8(Cu)in contrast to DUT-8(Ni,Co,Zn)where the closed pore phases are formed.

关键词： pillared layer metal-organic frameworks flexible behavior phase transition mesostructure texture gas adsorption

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A multiphase mesostructure mechanics approach to the study of the fracture-damage behavior of concrete

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Science China(Technological Sciences) 2008年第S2期51卷 8-24页

作者： TANG XinWei1,ZHANG ChuHan1 & SHI JianJun2 1 State Key Laboratory of Hydroscience and Engineering,Tsinghua University,Beijing 100084,China 2 Department of Urban Construction,Nanhua University,Hengyang 421001,China State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing China Department of Urban Construction Nanhua University Hengyang China

A multiphase mesostructure mechanical model is proposed to study the deformation and failure process of concrete considering its heterogeneity at the meso scopic level.Herein,concrete is taken as a type of three-component composite material composed of mortar matrix,aggregates and interfaces on the meso-scale.First,an efficient approach to the disposition of aggregates of concrete and a state matrix method to generate mesh coordinates for aggregates are proposed.Secondly,based on the nonlinear continuum damage mechanics,a meso-scale finite element model is presented with damage softening stress-strain relationship for describing the mechanical behavior of different components of concrete.In this method,heterogeneities of each component in the concrete are considered by assuming the material properties of three components conform to the Weibull distribution law.Finally,based on this multiphase meso-mechanics model,a simulation analysis of fracture behavior of a rock-fill concrete(RFC) beam is accomplished.The study includes experimental tests for determining basic mechanical parameters of three components of RFC and four-point flexural beam tests for verification of the model.It is preliminarily shown that the numerical model is applicable to studying failure mechanisms and process of concrete type material.

关键词： concrete multiphase mesostructure mechanics numerical simulation experimental research

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One-step fabrication of mesoporous sulfur-doped carbon nitride for highly selective photocatalytic transformation of native lignin to monophenolic compounds

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Chinese Chemical Letters 2023年第1期34卷 440-445页

作者： Conghao Ku Huiqin Guo Kexin Li Qiong Wu Liushui Yan Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle Nanchang Hangkong UniversityNanchang 330063China National-Local Joint Engineering Research Center of Heavy Metals Pollutants Control and Resource utilization Nanchang Hangkong UniversityNanchang 330063China Jiangxi Provincial Experimental Teaching Demonstration Center of Environmental Science and Engineering Nanchang Hangkong UniversityNanchang 330063China

Photocatalytic selective transform native lignin into valuable chemicals is an attractive but challenging task.Herein,we report a mesoporous sulfur-doped carbon nitride(MSCN-0.5)which is prepared by a facile one-step thermal condensation strategy.It is highly active and selective for the cleavage Cα-Cβbond inβ-O-4 lignin model compound under visible light radiation at room temperature,achieving 99%substrate conversion and 98%Cα-Cβbond cleavage selectivity.Mechanistic studies revealed that the Cβ-H bond of lignin model compounds activated by holes and generate key Cβradical intermediates,further induced the Cα-Cβbond cleavage by superoxide anion radicals(·O2-)to produce aromatic oxygenates.Waste Camellia oleifera shell(WCOS)was taken as a representative to further understand the reaction mechanisms on native lignin.33.2 mg of monophenolic compounds(Vanillin accounted for 22%and Syringaldehyde for 34%)can be obtained by each gram of WCOS lignin,which is 2.5 times as that of the pristine carbon nitride.The present work offers useful guidance for designing metal-free heterogeneous photocatalysts for Cα-Cβbond cleavage to harvest monophenolic compounds.

关键词： mesostructure Sulfur-doped carbon nitride Photocatalysis Lignin model compound Native lignin Monophenolic compounds

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Effects of pore size,mesostructure and aluminum modification on FDU-12 supported NiMo catalysts for hydrodesulfurization

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Petroleum Science 2020年第6期17卷 1737-1751页

作者： Pei Yuan Xue-Qin Lei Hong-Ming Sun Hong-Wei Zhang Chun-Sheng Cui Yuan-Yuan Yue Hai-Yan Liu Xiao-Jun Bao Ting-Hai Wang National Engineering Research Center of Chemical Fertilizer Catalyst School of Chemical EngineeringFuzhou UniversityFuzhou 350002People’s Republic of China State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing 102249People’s Republic of China

A series of NiMo/FDU-12 catalysts with tunable pore diameters and mesostructures have been controllably synthesized by adjusting the synthetic hydrothermal temperature and applied for the hydrodesulfurization of dibenzothiophene and its derivative.The state-of-the-art electron tomography revealed that the pore sizes of FDU-12 supports were enlarged with the increase in the hydrothermal temperature and the mesostructures were transformed from ordered cage-type pores to locally disordered channels.Meanwhile,the MoS2 morphology altered from small straight bar to semibending arc to spherical shape and finally to larger straight bar with the change of support structures.Among them,FDU-12 hydrothermally treated at 150℃possessed appropriate pore diameter and connected pore structure and was favorable for the formation of highly active MoS2 with curved morphology;thus,its corresponding catalyst exhibited the best HDS activity.Furthermore,it was indicated that the isomerization pathway could be significantly improved for HDS of 4,6-dimethyldibenzothiophene after the addition of aluminum,which was expected to be applied to the removal of the macromolecular sulfur compounds.Our study sheds lights on the relationship between support effect,active sites morphology and HDS performance,and also provides a guidance for the development of highly active HDS catalysts.

关键词： mesostructure FDU-12 NiMo catalysts Hydrodesulfurization Al modification

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Molecular pore-wall engineering of mesozeolitic conjugated polymers for photoredox hydrogen production with visible light

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Journal of Energy Chemistry 2017年第1期26卷 87-92页

作者： Mingwen Zhang Jinshui Zhang Yan Chen Xinchen Wang State Key Laboratory of Photocatalysis on Energy and Environment College of ChemistryFuzhou UniversityFuzhou 350002FujianChina

A chemical protocol based on molecular engineering of polymeric matrix is developed for the chemical optimization of ordered mesoporous carbon nitride (OMCN) in this study to address the concerns on the serious nanostructure-induced semiconductive defects, in particular the remarkable hypsochromic shift of absorption threshold and the increased excition dissociation energy. Physical characterizations demonstrate that the successful incorporation of 3-aminothiophene-2-carbonitrile (ATCN) aromatic donor in OMCN matrix can efficiently extend the pi-conjugated system, red-shift the optical absorption toward longer wavelengths and promote exciton splitting, thus well overcoming the serious semiconductive defects. In addition, the unique structural benefits of OMCN, such as the well-orientated nanoarchitectures with large specific surface area and uniform nanosized pore, have been well remained in ATCN-modified sample (OMCNA) via adjusting the ATCN/cyanamide molar ratio to minimize the unavoidable matrix disturbance. Hence, an obviously enhanced photocatalytic activity toward H-2 evolution and selective oxidation of alcohols are obtained on optimized OMCNA samples, greatly underlining the advantage of molecular engineering in supporting nanostructured photocatalysts. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.

关键词： Photocatalysis Graphitic carbon nitride Polymers mesostructure Water splitting

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Preparation of Mesoporous Nano-Hydroxyapatite Using a Surfactant Template Method for Protein Delivery

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Journal of Bionic Engineering 2012年第2期9卷 224-233页

作者： Xiaodong Wu Xiaofeng Song Dongsong Li Jianguo Liu Peibiao Zhang Xuesi Chen Department of Bone and Joint Surgery First Hospital of Jilin UniversityChangchun 130021P R.China Key Laboratory of Polymer Ecobiomaterials Changchun Institute of Applied ChemistryChinese Academy of SciencesChangehun 130022P.R.China

Mesoporous nano-hydroxyapatite （n-HA） has gained more and more attention as drug storage and release hosts. The aim of this study is to observe the effect of the ratio of surfactant to the theoretical yield of HA on the mesoporous n-HA, then to reveal the effect of the mesoporous nanostructure on protein delivery. The mesoporous n-HA was synthesized using the wet precipitation in the presence of cetyltrimethylammonium bromide （CTAB） at ambient temperature and normal atmospheric pressure. The morphology, size, crystalline phase, chemical composition and textural characteristics of the product were well characterized by X-ray Powder Diffraction （XRD）, Fourier Transform Infrared Spectroscopy （FTIR）, Scanning Electron Microscopy （SEM）, Transmission Electron Microscopy （TEM）, Dynamic Light Scattering （DLS） and N2 adsorption/desorption, respectively. The protein adsorption/release studies were also carried out by using Bovine Serum Albumin （BSA） as a model protein. The results reveal that the mesoporous n-HA synthesized with CTAB exhibits high pure phase, low crystallinity and the typical characteristics of the mesostructure. The BSA loading increases with the specific surface area and the pore volume of n-HA, and the release rates of BSA are different due to their different pore sizes and pore structures, n-HA synthesized with 0.5% CTAB has the highest BSA loading and the slowest release rate because of its highest surface area and smaller pore size. These mesoporous n-HA materials demonstrate a potential application in the field of protein delivery due to their bioactive, biocompatible and mesoporous properties.

关键词： hydroxyapatite nanoparticles mesostructure cetyltrimethylammonium bromide drug delivery

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Aqueous Synthesis of mesostructured BiVO_(4) Quantum Tubes with Excellent Dual Response to Visible Light and Temperature

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Nano Research 2010年第9期3卷 620-631页

作者： Yongfu Sun Yi Xie Changzheng Wu Shudong Zhang Shishi Jiang Hefei National Laboratory for Physical Sciences at Microscale University of Science and Technology of ChinaHefei 230026China

Analysis of the atomic structure of monoclinic BiVO4 reveals its fascinating structure-related dual response to visible light and temperature.Although there have been a few reported studies of its responses to visible light and temperature,an understanding of the effects of quantum size,particle shape or specific exposed facets on its dual responsive properties remains elusive;this is primarily due to the limited availability of high-quality monodisperse nanocrystals with extremely small sizes and specific_(4)exposed facets.Herein,we describe a novel assembly-fusion strategy for the synthesis of mesostructured monoclinic BiVO_(4)quantum tubes with ultranarrow diameter of 5 nm,ultrathin wall thickness down to 1 nm and exposed{020}facets,via a convenient hydrothermal method at temperatures as low as 100℃.Notably,the resulting high-quality quantum tubes possess significantly superior dual-responsive properties compared with bulk BiVO_(4)or even BiVO4 nanoellipsoids,and thus,show high promise for applications as visible-light photocatalysts and temperature indicators offering improved environmental quality and safety.This mild and facile methodology should be capable of extension to the preparation of other mesostructured inorganic quantum tubes with similar characteristics,giving a range of materials with enhanced dual-responsive properties.

关键词： mesostructure BiVO_(4) quantum tubes visible light temperature

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Formation of Lamellar mesostructured Crystalline Silica by Self-assembly of CTAB

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Chemical Research in Chinese Universities 2019年第3期35卷 359-362页

作者： CUI Kai FANG Yuxi XU Dongdong ZHANG Yunjuan HAN Lu CHE Shunai State Key Laboratory of Metal Matrix Composites School of Chemistry and Chemical Engineering Shanghai Jiao Tong UniversityShanghai 200240P. R. China School of Chemical Science and Engineenng Tongji UniversityShanghai 200092P. R. China Jiangsu Key Laboratory of Biofunctional Materials School of Chemistry and Materials ScienceNanjing Normal UniversityNanjing 210023P.R.China

Controlling organic-inorganic liquid crystal structures to form lamellar mesostructured crystalline silica nanosheets(LCS) was achieved by using the simple cationic surfactant cetyl trimethyl ammonium bromide(CTAB). The organic-inorganic interaction under the condtions of a high surfactant concentration and suitable synthesis temperature played an important role in the construction of mesostructured crystalline silica.

关键词： Lamellar mesostructure Crystalline silica Self-assembly Cetyl trimethyl ammonium bromide Liquid crystal

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