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High-efficiency stabilization of dredged sediment using nano-modified and chemical-activated binary cement

Journal of Rock Mechanics and Geotechnical Engineering 2023年第8期15卷 2117-2131页

作者： lei lang Bing Chen Jiangshan Li State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China Department of Civil Engineering Shanghai Jiao Tong UniversityShanghai200240China

High-efficiency disposal of dredged sediment(DS)has become an imperative geo-environmental engineering issue due to the limited landfilling space and severe environmental *** study firstly developed a novel high-efficiency nano-modified and chemical-activated binary cement(NBC),which was composed of binary cement(BC)consisting ordinary Portland cement(OPC)and ground granulated blast-furnace slag(GGBS),chemical-activator and *** effects of chemical-activation and nano-modification on the strength development of BC-stabilized DS(BCDS),and the optimum mix of NBC were respectively achieved via a series of unconfined compressive strength and orthogonal ***,the high-efficiency and economic applicability of NBC in DS stabilization were evaluated by comparing with ***,the microstructure and mineral composition evolutions inside NBCstabilized DS(NDS)were explored by conducting X-ray diffraction(XRD)and scanning electron microscopy(SEM)*** results show that both chemical-activation and nano-modification could effectively improve the strength gain of BCDS,and compared with single chemical-activator and nanomodifier,the composite chemical-activators and nano-modifiers exhibited better *** on BC with OPC/GGBS mass ratio of 1:1,both anhydrous sodium metasilicate/anhydrous sodium sulfate(SM/SS)and nano-SiO_(2)/nano-MgO(NS/NM)with mass ratio of 1:9 were respectively determined to be optimum chemical-activator and *** optimum mass ratio of BC,SM/SS and NS/NM was 20:2:1,*** optimum mix of *** with OPC,NBC exhibited higher stabilization efficiency and better economic *** generation of calcium silicate hydrate(CSH),calcium aluminate hydrate(CAH)and ettringite contributed to the formation of dense cemented soil matrix inside NDS,and a conceptual micro-mechanism model characterizing the strength development under the coupling action of chemical-activation and nano-modification was prop

关键词： Dredged sediment(DS) Stabilization Chemical-activation Nano-modification Microstructure

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Modification of nanoparticles for the strength enhancing of cementstabilized dredged sludge

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Journal of Rock Mechanics and Geotechnical Engineering 2021年第3期13卷 694-704页

作者： lei lang Bing Chen Haijuan Duan State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghaiChina Shanghai Key Laboratory for Digital Maintenance of Buildings and Infrastructure Department of Civil EngineeringShanghai Jiao Tong UniversityShanghaiChina

This paper investigates the effectiveness of nano-modification on the strength enhancement of cementstabilized dredged sludge(CDS).Three types of nanoparticles including nano-SiO2(NS),nano-Al2O3(NA)and nano-MgO(NM)were used as cement admixtures for dredged sludge *** of single nanoparticle content,mass ratio of composite nanoparticles and curing time on the strength development of CDS were evaluated via a series of unconfined compressive strength(UCS)*** pH evolutions of CDS caused by nanoparticles were also examined by a range of pH ***,micromechanisms reflecting the strength evolutions were analyzed by performing scanning electron microscopy(SEM)and X-ray diffraction(XRD)*** results indicated that adding nanoparticles can significantly improve the UCS of *** single nano-modification,the optimum contents of NS,NA and NM were 4%e6%,6%and 8%,which can increase the 7-and 28-d UCSs of CDS by 38%and 50%,17%and 35%,65%and 67%,*** with single nano-modification,composite nano-modifications were more effective in improving the strength gain of *** optimum mass ratios of composite nanoparticles,namely NS/NA,NS/NM and NA/NM,were 9/1,3/7 and 3/7,*** on the strength growth rate,the composite nanoparticles with NS/NM of 3/7 were highly *** addition of nanoparticles obviously affected the pH evolution of CDS,which was mainly determined by the difference of OHproduction and consumption inside nano-modified *** microstructural analysis revealed that C-S-H and C-A-H gels are the main cementitious products,and the addition of nanoparticles can obviously contribute to a denser and more homogenous microstructure of CDS.

关键词： Cement-stabilized dredged sludge(CDS) Nano-modification Strength development pH level Microstructure

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Tensile strength behavior of cement-stabilized dredged sediment reinforced by polypropylene fiber

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Frontiers of Structural and Civil Engineering 2024年第3期18卷 380-392页

作者： lei lang Jiangshan LI Xin CHEN Lijun HAN Ping WANG State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicChinese Academy of SciencesWuhan 430071China Hubei Provincial Key Laboratory of Contaminated Sludge and Soil Science and Engineering Wuhan 430071China University of Chinese Academy of Sciences Beijing 100049China

This study evaluated the feasibility of using polypropylene fiber(PF)as reinforcement in improving tensile strength behavior of cement-stabilized dredged sediment(CDS).The effects of cement content,water content,PF content and length on the tensile strength and stress–strain behavioral evolutions were evaluated by conducting splitting tensile strength ***,the micro-mechanisms characterizing the tensile strength behavior inside PF-reinforced CDS(CPFDS)were clarified via analyzing macro failure and microstructure *** results indicate that the highest tensile strengths of 7,28,60,and 90 d CPFDS were reached at PF contents of 0.6%,1.0%,1.0%,and 1.0%,exhibiting values 5.96%,65.16%,34.10%,and 35.83%higher than those of CDS,***,3 mm,PF of showed the best reinforcement *** CPFDS exhibited obvious tensile strain-hardening characteristic,and also had better ductility than *** mix factor(C_(C)^(a)/C_(w)^(b))and time parameter(q_(t0)(t))of CDS,and the reinforcement index(k_(t-PF))of CPFDS were used to establish the tensile strength prediction models of CDS and CPFDS,considering multiple *** PF“bridge effect”and associated cementation-reinforcement coupling actions inside CPFDS were mainly responsible for tensile strength behavior *** key findings contribute to the use of CPFDS as recycled engineering soils.

关键词： dredged sediment chemical stabilization fiber reinforcement splitting tensile strength micro-mechanisms

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Coupling effect of cement-stabilization and biopolymer-modification on the mechanical behavior of dredged sediment

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第8期16卷 3284-3298页

作者： lei lang Jiangshan Li Xiao Huang Ping Wang Wei Zhang State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China Hubei Provincial Key Laboratory of Contaminated Sludge and Soil Science and Engineering Wuhan430071China University of Chinese Academy of Sciences Beijing100049China

Nowadays,biopolymer stabilization as a promising eco-friendly approach in soft ground improvement has attracted wide ***,the feasibility of using biopolymer as a green additive of cementstabilized dredged sediment(CDS)with high water content is still *** this study,guar gum(GG)and xanthan gum(XG)were adopted as typical biopolymers,and a series of unconfined compressive strength(UCS),splitting tensile strength(STS)and scanning electron microscopy(SEM)tests were performed to evaluate the mechanical and microstructural properties of XG-and GG-modified CDSs considering several factors including biopolymer modification,binderesoil ratio and wateresolid ***,the micro-mechanisms revealing the evolutions of mechanical properties of biopolymermodified CDS were *** results indicate that the addition of XG can effectively improve the strength of CDS,while the GG has a side *** XG content of 9%was recommended,which can improve the 7 d-and 28 d-UCSs by 196%and 51.8%,together with the 7 d-and 28 d-STSs by 118.3%and 42.2%,*** the binderesoil ratio or decreasing the wateresolid ratio significantly improved the strength gaining but aggravated the brittleness characteristics of *** XG to CDS contributed to the formation of microstructure with more compactness and higher cementation degrees of ordinary Portland cement(OPC)-XG-stabilized DS(CXDS).The micro-mechanism models revealing the interactions of multiple media including OPC cementation,biopolymer film bonding and bridging effects inside CXDS were *** key findings confirm the feasibility of XG modification as a green and high-efficiency mean for improving the mechanical properties of CDS.

关键词： Dredged sediment(DS) Stabilization Biopolymer modification Mechanical properties Micro-mechanism

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Autogenous healing mechanism of cement-based materials

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Frontiers of Structural and Civil Engineering 2023年第6期17卷 948-963页

作者： Desheng LI Hao ZHENG Kang GU lei lang Shang SHI Bing CHEN Department of Civil Engineering School of ScienceNanjing University of Science and TechnologyNanjing210094China School of Transportation Science and Engineering Harbin Institute of TechnologyHarbin150090China State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai200240China State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsWuhan430071China

Autogenous self-healing is the innate and fundamental repair capability of cement-based materials for healing *** researchers have investigated factors that influence autogenous ***,systematic research on the autogenous healing mechanism of cement-based materials is *** healing process mainly involves a chemical process,including further hydration of unhydrated cement and carbonation of calcium oxide and calcium ***,the autogenous healing process is influenced by the material constituents of the cement composite and the ambient *** this study,different factors influencing the healing process of cement-based materials were *** electron microscopy and optical microscopy were used to examine the autogenous healing mechanism,and the maximum healing capacity was ***,detailed theoretical analysis and quantitative detection of autogenous healing were *** study provides a valuable reference for developing an improved healing technique for cement-based composites.

关键词： autogenous healing cement-based materials healing mechanism aggregation effect

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课程思政与美育融合建设模式探索——以环境科学与工程专业新生研讨课为例

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教育教学论坛 2025年第4期 5-8页

作者：周颖郎建垒王晓琦北京工业大学环境与生命学部北京100124

新生研讨课开设的主要目的是提升大一新生的专业认知。在我国大力推进生态文明的大背景下,环境类专业课程思政元素与美育元素亟须挖掘并融合,以达到同向同行的育人目的。以环境科学与工程专业的新生研讨课为例,从内容体系构建、研讨话... 详细信息

新生研讨课开设的主要目的是提升大一新生的专业认知。在我国大力推进生态文明的大背景下,环境类专业课程思政元素与美育元素亟须挖掘并融合,以达到同向同行的育人目的。以环境科学与工程专业的新生研讨课为例,从内容体系构建、研讨话题设计、案例实践引领、互动模式创新、教师队伍完善等方面,探索课程思政与美育融合建设方法和途径,在助力学生加强专业认识的同时,传递正能量,引导学生树立正确的价值观和健康的审美观。

关键词：课程思政美育新生研讨课环境保护

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Periodontal-orthodontic interdisciplinary management of a“periodontally hopeless”maxillary central incisor with severe mobility:A case report and review of literature

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World Journal of Clinical Cases 2022年第14期10卷 4550-4562页

作者： Ke Jiang Li-Shan Jiang Hou-Xuan Li lang lei Department of Orthodontics Nanjing Stomatological HospitalMedical School of Nanjing UniversityNanjing 210008Jiangsu ProvinceChina Department of Periodontics Nanjing Stomatological HospitalMedical School of Nanjing UniversityNanjing 210008Jiangsu ProvinceChina

BACKGROUND Treating periodontally hopeless teeth with advanced bone resorption and severe tooth mobility is a great challenge for both orthodontists and ***-induced periodontal inflammation and occlusal trauma-related inflammation may synergistically aggravate tooth *** case report illustrates that even periodontally hopeless teeth can be saved and have long-term stability with comprehensive periodontal treatment to control periodontal inflammation and promote periodontal bone regeneration and intricate orthodontic mechanical control to correct cross bite and occlusal *** SUMMARY A 27-year-old female patient whose chief complaint was severe tooth mobility and discomfort of the maxillary incisor was diagnosed with severe aggressive periodontitis by clinical and radiographic *** reduce tooth mobility and establish stable occlusion,we combined orthodontic treatment with periodontal therapy to preserve the *** treatment was performed after basic periodontal therapy and periodontal *** loosened upper right central incisor was successfully retained,and the periodontal tissue remained stable during *** Teeth with severe mobility and bone loss can be saved through interdisciplinary treatment when periodontal inflammation is strictly controlled.

关键词： Occlusal trauma Periodontally hopeless teeth Periodontitis Orthodontics Guided tissue regeneration Interdisciplinary management Case report

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Effect of siRNA interference on nerve growth factor in intervertebral disc inflammation rats

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Asian Pacific Journal of Tropical Medicine 2014年第9期7卷 739-743页

作者： Ming-lei lang Ai-Lin Qin Jian-Min Li Peng Fu Department of Orthopedics Qilu Hospital Affiliated to Shandong University Shengli Oilfield Central Hospital Department of Orthopedics Gaomi People's Hospital

Objective:To investigate the inhibition effect of siRNA interference on NGF induced by inflammatory factor IL-6,and JUL—1 so as to provide novel targets for clinical treatment of discogenic low back ***:The intervertebral disc nucleus and annulus fibrosus cells of rats were separated-The cells were co-cultured with different concentrations(10 nmol/L,20nmol/L,50 nmol/L,100 nmol/L)of IL-6 and IL-1β.The NGF-siRNA was leaded into the cocultured cells with its import ability assessed by flow cytometry instrument tests,hefore and after which the NCF mRNA expression was detected by real-time Q-PCR and the NGF content was detected by ***:Flow cytometry instrument test results showed that the NGFsiRNA cell conversion rate was 99.8%.Real-time Q-PCR detection results showed that compared with negative control group,the NGF mRNA expression of co-cultured cells treated by 10 nmol/L,20 nmol/L,50 nmol/L,100 nmol/L IL-6 and IL-1βwere respectively raised 3.4,3.7,4.7,3.7 times which were all significantly down-regulated after the import of *** detection results showed that compared with negative control group,the NGF content of cocultured medium treated by 10 nmol/L,20 nmol/L,50 nmol/L,100 nmol/L I-L6 and IL-1βwere respectively raised 2.9,3.3,4.5,7.4 times which were all significantly decreased after the import of ***:These molecular biological results suggest that inflammatory factor IL-6 and IL-1βcould stimulate NCF on intervertebral disc cells in vitro culture model and its efficiency is concentration dependent,while siRNA interference can inhibit the stimulation effect of IL-6 and IL-1βon intervertebral disc cell,which provides a new targets for the clinical treatment of discogenic low back pain.

关键词： RNA Small interfering Nerve growth factor Low back pain Intervertebral disk displacement

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Investigation on Thermal Insulation and Mechanical Strength of Lightweight Aggregate Concrete and Porous Mortar in Cold Regions

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Journal of Renewable Materials 2022年第12期10卷 3167-3183页

作者： Jianan Wu Ke Xue Zhaowei Ding lei lang Kang Gu Xiaolin Li Mingli Zhang Desheng Li Ningbo City College of Vocational Technology NingboChina College of Water Conservancy and Hydropower Engineering Sichuan Agricultural UniversityYa’anChina State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghaiChina College of Civil Engineering and Architecture Jiaxing UniversityJiaxingChina Department of Civil Engineering Lanzhou University of TechnologyLanzhouChina Department of Civil Engineering College of ScienceNanjing University of Science and TechnologyNanjingChina

Thermal insulation is an important indicator to evaluate the construction material in cold region *** we know,adding the industrial waste as lightweight aggregate or creating the pore inside the cement-based composite could make the texture loose,and the thermal insulating capacity of the material would be improved with this *** these methods,the industrial by-product and engineering waste could be cycled in an efficient ***,after service the fragmented cement composites paste could be used as aggregate in the thermal insulating concrete *** the porous texture is not favorable for the mechanical strength and long-term durability in a cold *** balance the above three requirements from two opposite directions,different processing methods were applied to create the thermal insulation concrete/***,the organic/inorganic lightweight aggregate,including the Expanded Polystyrene(EPS),Expanded Perlite(EP),and Ceramsite(CRMST)particles,were applied to create the Lightweight Aggregate Concrete(LWAC).As the comparative tests,the expanded Superabsorbent Polymer(SAP)hydrogel and Air-Entraining Agent(AEA)were also introduced to create the porous *** above concrete/mortar was tested in the normal state and under the Freeze-Thaw cycle to explore the engineering performance in cold *** the experimenting process,the thermal insulation,mechanical strength,and frost resistance of these cement-based composites were investigated,and an optimal thermal insulation concrete/mortar was determined.

关键词： Thermal insulation mechanical strength cement-based composite freeze-thaw cycle frost resistance

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室内可见光蜂窝网络信道特性研究

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光电子．激光 2015年第1期26卷 81-85页

作者：郎磊贾倩中国电子科技集团公司第五十四研究所河北石家庄050081

基于可见光通信（VLC）技术的LED蜂窝网络,设想作为第5代移动通信技术在室内应用的主要备选方式之一,得到越来越多的关注。本文采用广义光线追踪算法对符合蜂窝布局的室内可见光信道特性进行研究,分析了不同LED发光角度条件下信道冲击... 详细信息

基于可见光通信（VLC）技术的LED蜂窝网络,设想作为第5代移动通信技术在室内应用的主要备选方式之一,得到越来越多的关注。本文采用广义光线追踪算法对符合蜂窝布局的室内可见光信道特性进行研究,分析了不同LED发光角度条件下信道冲击响应、路径损耗和信道时延等信道特性。随着LED半功率角从30°增大到60°,系统路径损耗与信道时延也整体增大,其中总体路径损耗变化范围为32-36.5dB,信道时延的变化范围为0.4-1.5ns。

关键词：可见光通信(VLC) 蜂窝网络光线追踪算法

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