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Co-occurrence of per- and polyfluoroalkyl substances, heavy metals and polycyclic aromatic hydrocarbons and their composite impacts on microbial consortium in soil: A field study

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Pedosphere 2024年第4期34卷 736-748页

作者： Meng ZHANG Qing WANG Xin SONG Mukhtiar ALI Zhiwen TANG Xin LIU Zhuanxia ZHANG Shurong MA Jinhui BI Zhongyuan LI Key Laboratory of Saline-Alkali Vegetation Ecology Restoration Northeast Forestry UniversityHarbin 150040China Key Laboratory of Soil Environment and Pollution Remediation Institute of Soil ScienceChinese Academy of SciencesNanjing 210008China University of Chinese Academy of Sciences Beijing 100049China Center International Group Co. Ltd.Beijing 101160China china construction Eighth engineering division corp. Ltd.Shanghai 200122China

This is the first study to report the co-occurrence of per-and polyfluoroalkyl substances(PFASs),heavy metals,and polycyclic aromatic hydrocarbons(PAHs)and their impacts on the native microbial consortium in soil due to the long-term *** PFASs,heavy metals,and PAHs were detected in soil samples collected at 2–6 m below the ground surface at different sampling locations in a steel-making *** total concentrations of PFASs varied from 6.55 to 19.79 ng g^(-1),with perfluorooctane sulfonate(PFOS),perfluorobutane sulfonate,and 6:2 chlorinated polyfluorinated ether sulfonate(alternative of PFOS)being the predominant *** concentrations of arsenic,cadmium,and lead were detected in the ranges of 4.40–1270.00,0.01–8.67,and 18.00–647.00 mg kg^(-1),respectively,and the concentration of total PAHs was detected in the range of 1.02–131.60 mg kg^(-1).The long-term exposure to mixed contaminants of PFASs,heavy metals,and PAHs led to lower richness and diversity of microbial communities in *** soil bacterial communities were mainly composed of Pseudomonas,norank_p_GAL15,Leptothrix,norank_o_Rokubacteriales,and *** between soil environmental factors and microbial communities indicated that cation exchange capacity and total phosphorus were two key factors in shaping the composition of native microbial ***,Arthrobacter,Leptothrix,and Sphingobium were found to be significantly positively correlated with PFAS concentrations,indicating that these genera could tolerate the stress exerted by PFASs,along with the stress imposed due to the presence of heavy metals or/and PAHs.

关键词： arsenic cation exchange capacity mixed contaminant native microbial community perfuorooctane sulfonate total phosphorus

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Visible transparent,infrared stealthy polymeric films with nanocoating of ITO@MXene enable efficient passive radiative heating and solar/electric thermal conversion

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Nano Research 2023年第2期16卷 3326-3332页

作者： Xingyuan Du Xiangxin Li Yuxuan Zhang Xinyi Guo Zhengji Li Yanxia Cao Yanyu Yang Wanjie Wang Jianfeng Wang College of Materials Science and engineering Henan Key Laboratory of Advanced Nylon Materials and ApplicationZhengzhou UniversityZhengzhou 450001China china construction seventh engineering division corp.ltd. Zhengzhou 450004China

Visible transparent yet low infrared-emissivity(ε)polymeric materials are highly anticipated in many applications,whereas the fabrication of which remains a formidable ***,visible transparent,flexible,and low-εpolymeric films were fabricated by nanocoating decoration of indium tin oxide(ITO)and MXene on polyethylene terephthalate(PET)film surface through magnetron sputtering and spray coating,*** obtained PET-ITO@MXene(PET-IM)film exhibits lowεof 24.7%and high visible transmittance exceeding 50%,endowing it with excellent visible transparent infrared stealthy by reducing human skin radiation temperature from 32 to 20.8°C,and remarkable zero-energy passive radiative heating capability(5.7°C).Meanwhile,the transparent low-εPET-IM film has high solar absorptivity and electrical conductivity,enabling superior solar/electric to thermal conversion ***,the three heating modes of passive radiative and active solar/electric can be integrated together to cope with complex heating *** visible transparent low-εpolymeric films are highly promising in infrared stealth,building daylighting and thermal management,and personal precision heating.

关键词： transparent polymeric film nanocoating decoration ITO@MXene low infrared emissivity passive radiative heating solar/electric heating

Model test to investigate failure mechanism and loading characteristics of shallow-bias tunnels with small clear distance

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Journal of Central South University 2016年第12期23卷 3312-3321页

作者：雷明锋林大涌杨伟超施成华彭立敏黄娟 School of Civil engineering Central South University china construction Fifth engineering division corp. Ltd.

Based on the similarity theory,a tunnel excavation simulation testing system under typical unsymmetrical loading conditions was *** this system,the failure mechanism of surrounding rock of shallow-bias tunnels with small clear distance was analyzed along with the load *** results show that:1) The failure process of surrounding rock of shallow-bias tunnels with small clear distance consists of structural and stratum deformation induced by tunnel excavation; Microfracture surfaces are formed in the tunnel surrounding rock and extend deep into the rock mass in a larger density; Tensile cracking occurs in shallow position on the deep-buried side,with shear slip in deep rock *** the meantime,rapid deformation and slip take place on the shallow-buried side until the surrounding rocks totally *** production and development of micro-fracture surfaces in the tunnel surrounding rock and tensile cracking in the shallow position on the deep-buried side represent the key stages of failure.2) The final failure mode is featured by an inverted conical fracture with tunnel arch as its top and the slope at tunnel entrance slope as its *** range of failure on the deep-buried side is significantly larger than that on the shallow-buried *** difference becomes more prominent with the increasing bias *** distinguishes it from the "linear fracture surface" model is that the model proposed has a larger fracture angle on the two ***,the bottom of the fracture is located at the springing line of tunnel arch.3) The total vertical load increases with bias *** with the existing methods,the unsymmetrical loading effect in measurement is more *** last,countermeasures are proposed according to the analysis results: during engineering process,1) The surrounding rock mass on the deep-buried side should be reinforced apart from the tunnel surrounding rock for shallow-buried tunnels with small clear distance;

关键词： shallow-bias tunnels with small spacing failure mechanism loading characteristics model test

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Upper bound analytical solution for surrounding rock pressure of shallow unsymmetrical loading tunnels

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Journal of Central South University 2015年第6期22卷 2339-2347页

作者：雷明锋彭立敏施成华谢友均谭立新 School of Civil engineering Central South University china construction Fifth engineering division corp. Ltd.

By combining the results of laboratory model tests with relevant flow rules, the failure mode of shallow unsymmetrical loading tunnels and the corresponding velocity field were established. According to the principle of virtual power, the upper bound solution for surrounding rock pressure of shallow unsymmetrical loading tunnel was derived and verified by an example. The results indicate that the calculated results of the derived upper bound method for surrounding rock pressure of shallow unsymmetrical loading tunnels are relatively close to those of the existing "code method" and test results, which means that the proposed method is feasible. The current code method underestimates the unsymmetrical loading feature of surrounding rock pressure of shallow unsymmetrical loading tunnels, so it is unsafe; when the burial depth is less or greater than two times of the tunnel span and the unsymmetrical loading angle is less than 45°, the upper bound method or the average value of the results calculated by the upper bound method and code method respectively, is comparatively reasonable. When the burial depth is greater than two times of the tunnel span and the unsymmetrical loading angle is greater than 45°, the code method is more suitable.

关键词： tunnel shallow buried tunnel unsymmetrical loading ultimate analysis method upper bound solution

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Analysis of the Performances and Optimization of Polyurethane Concrete with a Large Percentage of Fly Ash

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Fluid Dynamics & Materials Processing 2023年第2期19卷 437-450页

作者： Tingting Huo Jiaquan Xue Zhi’an Fu Wuchang University of Technology Wuhan430223China china Metallurgical construction engineering Group Co. Ltd.Chongqing400080China china construction Fourth engineering division corp. Ltd.Guangzhou510665China

The properties of polyurethane concrete containing a large amount of fly ash are investigated,and accordingly,a model is introduced to account for the influence of fly ash fineness,water ratio,and loss of ignition(LOI)on its mechanical *** research shows that,after optimization,the concrete has a compressive strength of 20.8 MPa,a flexural strength of 3.4 MPa,and a compressive modulus of elasticity of 19.2 *** main factor influencing 28 and 90 d compressive strength is fly ash content,water-binder ratio,and early strength agent content.

关键词： Water-containing unsaturated polyurethane concrete fly ash ratio test strength test water content test mechanical properties

TBM performance prediction using LSTM-based hybrid neural network model:Case study of Baimang River tunnel project in Shenzhen,china

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Underground Space 2023年第4期11卷 130-152页

作者： Qihang Xu Xin Huang Baogang Zhang Zixin Zhang Junhua Wang Shuaifeng Wang Department of Geotechnical engineering College of Civil EngineeringTongji UniversityShanghai 200092China State Key Laboratory of Geotechnical and Underground engineering Tongji UniversityShanghai 200092China china construction Fourth engineering division corp.ltd Guangzhou 510665China

Accurately predicting tunnel boring machine(TBM)performance is beneficial for excavation efficiency enhancement and risk miti-gation of TBM *** this paper,we develop a long short-term memory(LSTM)based hybrid intelligent model to predict two key TBM performance parameters(advance rate and cutterhead torque).The model combines the LSTM,BN,Dropout and Dense layers to process the raw data and improve the fitting *** features,including the ground formation properties,tunnel route cur-vature,tunnel location and TBM operational parameters,are divided into historical/real-time time-varying parameters,time-invariant parameters and historical/real-time output prediction *** effectiveness of the proposed model is verified based on a large moni-toring database of the Baimang River Tunnel Project in Shenzhen,south *** then discuss the influence of the prediction mode,neural network structure and time division interval length of historical data on the prediction *** significance evaluation of input features shows that the historical output prediction has the largest influence on the prediction accuracy,and the influence of ground properties is *** is also found that the correlations between input features and the output prediction are coincident with their interrelationships with the ground properties and ease of TBM ***,it is found that the prediction results are most affected by the total propulsion force followed by the rotation speed of the *** established model can provide useful guidance for construction personnel to roughly grasp the possible TBM status from the prediction results when adjusting the operational parameters.

关键词： TBM performance LSTM Deep learning Neural network Advance rate Cutterhead torque

Comparison of Coarse Graining DEM Models Based on Exact Scaling Laws

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Computer Modeling in engineering & Sciences 2021年第6期127卷 1133-1150页

作者： Bin Zhang Yiming Huang Tingting Zhao School of Economics and Business Administration Chongqing UniversityChongqing400030China CMCU engineering Co. Ltd.Chongqing400041China Sichuan University Chengdu610065China china construction Eighth engineering division corp. LTD SouthwestChengdu610000China College of Mechanical and Vehical engineering Taiyuan Univeristy of TechnologyTaiyuan030024China

The simulation of a large number of particles requires unacceptable computational time that is the most criticalproblem existing in the industrial application of the DEM. Coarse graining is a promising approach to facilitatethe application of DEM to industrial problems. While the current coarse graining framework is often developedin an ad-hoc manner, leading to different formulations and different solution accuracy and efficiency. Therefore,in this paper, existing coarse graining techniques have been carefully analysed by the exact scaling law which canprovide the theory basis for the upscaling method. A proper scaling rule for the size of particles and samples as wellas interaction laws have been proposed. The scaling rule is applied to a series simulations of biaxial compressiontests with different scale factors to investigate the precision of the coarse graining system. The error between theoriginal system and the coarse system shows a growing tendency as the scale factor increases. It can be concludedthat the precision of the coarse graining system is accepted when applying scaling rules based on the exact scalinglaws.

关键词： Discrete element method coarse graining exact scaling scale laws

Mechanical Properties and Durability of Sustainable Concrete Manufactured Using Ceramic Waste:A Review

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Journal of Renewable Materials 2023年第2期11卷 937-974页

作者： Peng Zhang Peishuo Zhang Jingjiang Wu Zhenhui Guo Yong Zhang Yuanxun Zheng School of Water Conservancy engineering Zhengzhou UniversityZhengzhou450001China Communications construction Company of CSCEC 7th division Co. Ltd.Zhengzhou450004China

Green and sustainable concrete has attracted significant attention from the construction industry and researchers since it was *** ceramic waste materials are often directly buried in the ground or placed in an open dump,and the accumulation of ceramic waste contributes to environmental pollution,which makes the recycling of ceramic waste quite *** to the pozzolanic activity,excellent mechanical properties and durability,industrial ceramic waste is considered as a suitable substitute for cement or natural aggregates to fabricate renewable *** this paper,the pozzolanic activity of ceramic waste and the workability,mechanical performance,and durability of ceramic concrete are *** addition,the most recent research results pertaining to ceramic concrete are *** ceramic powder improves the workability,compressive strength,resistance to chloride penetration,and carbonation resistance of concrete to a certain *** containing ceramic as the aggregate has a lower mechanical performance than ordinary ***,the resistance to chloride penetration,freeze-thaw resistance,and high-temperature resistance of ceramic concrete are *** concrete is environmentally friendly,requires fewer energy resources to manufacture than ordinary concrete,and has excellent engineering ***,further research is required for future engineering applications.

关键词： Sustainable concrete ceramic waste pozzolanic activity mechanical properties durability

Experimental investigation on migration of typical heavy metals under preferential flow

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Yantu Lixue/Rock and Soil Mechanics 2020年 41卷 292-298页

作者： Zhang, Wen-Jie Jiao, Wei-Guo Geng, Xiao Ji, Yong-Xin School of Mechanics and engineering Science Shanghai University Shanghai 200072 China School of Civil engineering Guizhou Institute of Technology Guiyang Guiyang 550003 China Shanghai Shenyuan Geotechnical engineering Co. Ltd. Shanghai 200011 China engineering Technology Research Institute (Technology Center) of china construction Fourth engineering division Co. Ltd Guangzhou 510665 China

Heavy metals discharged from industrial and agricultural activities can migrate downward along with flow water and cause pollution of soil and groundwater. Large pores and cracks are widespread in surface soil due to dry-wet cycles, plant roots, and earthworm activities, which form preferential flow paths for heavy metals. The assumption of uniform porous media cannot reflect the complicated characteristic of surface soil. The typical heavy metals with different adsorption properties include cadmium, lead and chromium(VI) were selected to study their adsorption characteristics on Shanghai surface silty clay by batch tests. Dye tracer tests are used to determine the preparation parameters of soil column with preferential flow characteristics. The leaching tests under preferential flow conditions were carried out and compared with that of the homogeneous soil column. The concentration and adsorption of pore solution at various depths were analyzed. The results show that the adsorption of chromium(VI) on the silty clay was much lower than that of cadmium and lead. Under preferential flow condition, the migration depth of cadmium becomes much deeper, resulting in a much higher concentration and adsorption of pore fluid, which increases the pollution risk to the soil and groundwater. The effluent concentration of chromium(VI) equivalent to the source concentration is much faster under the preferential flow, and the lower limit of accumulated chromium(VI) concentration and total environmental capacity in the soil column with preferential flow are much lower than that of the homogeneous soil column. The adsorption of chromium(VI) is lower than the equilibrium concentration obtained by batch adsorption tests. The chromium(VI) can migrate downward quickly along the preferential path because it is difficult to be adsorbed. The migration rate of lead under preferential flow condition is larger than in the homogeneous soil column. The adsorption in the deeper depth of soil colu

关键词： Adsorption