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In situ and on-line monitoring of cadmium in soil pore water using an automatic sampling integrated electrochemical sensor

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Science China(Technological Sciences) 2024年第9期67卷 2894-2904页

作者： KUANG JiaJie WEN JunLin CAI XiXi ZHOU LiHua yuan yong Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control School of Environmental Science and EngineeringInstitute of Environmental Health and Pollution ControlGuangdong University of TechnologyGuangzhou 510006China School of Biomedical and Pharmaceutical Sciences Guangdong University of TechnologyGuangzhou 510006China

Cadmium(Cd) contamination in soil pore water is the primary pathway for Cd uptake by food crops,such as rice(Oryza sativa L.),posing significant risks to both food safety and human *** study presents a novel soil pore water metal sensor(SPW-Msensor) for in situ and online monitoring of Cd in soil pore water(Cd_(pw)).The SPW-Msensor integrates an automated sampling device,comprising a Rhizon sampler and a reciprocating series pump with an independent dual plunger drive,along with a portable electrochemical sensor consisting of a screen-printed electrode,flow cell,and portable *** SPW-Msensor enables the detection of Cd within a linear range of 50 to 300 ppb while exhibiting high anti-interference ***,it demonstrates excellent repeatability(relative standard deviation values(RSDs)<3.6%) across 30 measurements conducted within a 2-h *** method exhibits good agreement with results obtained using the standard ICP-MS method(RSDs<5%).Additionally,this study establishes a positive correlation between Cd_(pw)detected by the SPW-Msensor and total Cd concentration(Cd_(total)) in the soil with an R^(2) value equal to *** acquired from the SPW-Msensor can be utilized for predicting Cd_(total)through partial least squares regression modeling,achieving model quality score(Q^(2)) of 0.69,adjusted R^(2) of 0.9345,and root mean square error(RMSE) of *** SPW-Msensor demonstrates real-time monitoring capabilities for assessing Cd levels in acidified *** SPW-Msensor offers an efficient approach for in-situ and continuous monitoring of Cd_(pw)that provides valuable insights applicable to environmental and agricultural domains.

关键词： cadmium pore water electrochemical sensor in-situ monitoring soil

Effects of Blade Number on Characteristics of Centrifugal Pumps

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Chinese Journal of Mechanical Engineering 2010年第6期23卷 742-747页

作者： LIU Houlin WANG yong yuan Shouqi TAN Minggao WANG Kai Research Center of Fluid Machinery Engineering and Technology Jiangsu University Zhenjiang 212013 China

The blade number of impeller is an important design parameter of pumps, which affects the characteristics of pump heavily. At present, the investigation focuses mostly on the performance characteristics of axis flow pumps, the influence of blade number on inner flow filed and characteristics of centrifugal pump has not been understood completely. Therefore, the methods of numerical simulation and experimental verification are used to investigate the effects of blade number on flow field and characteristics of a centrifugal pump. The model pump has a design specific speed of 92.7 and an impeller with 5 blades. The blade number is varied to 4, 6, 7 with the casing and other geometric parameters keep constant. The inner flow fields and characteristics of the centrifugal pumps with different blade number are simulated and predicted in non-cavitation and cavitation conditions by using commercial code FLUENT. The impellers with different blade number are made by using rapid prototyping, and their characteristics are tested in an open loop. The comparison between prediction values and experimental results indicates that the prediction results are satisfied. The maximum discrepancy of prediction results for head, efficiency and required net positive suction head are 4.83%, 3.9% and 0.36 m, respectively. The flow analysis displays that blade number change has an important effect on the area of low pressure region behind the blade inlet and jet-wake structure in impellers. With the increase of blade number, the head of the model pumps increases too, the variable regulation of efficiency and cavitation characteristics are complicated, but there are optimum values of blade number for each one. The research results are helpful for hydraulic design of centrifugal pump.

关键词： centrifugal pump blade number flow field simulation characteristics prediction experiment

Cloud-based smartphone-assisted chemiluminescent assay for rapid screening of electroactive bacteria

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Science China(Technological Sciences) 2023年第3期66卷 743-750页

作者： WEN JunLin HE DaiGui LUO SongQing ZHOU ShunGui yuan yong Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control School of Environmental Science and EngineeringInstitute of Environmental Health and Pollution ControlGuangdong University of TechnologyGuangzhou 510006China College of Artificial Intelligence Guangdong Mechanical&Electrical PolytechnicGuangzhou 510550China Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation College of Resources and EnvironmentFujian Agriculture and Forestry UniversityFuzhou 350002China

Electroactive bacteria(EAB)can transfer electrons to exocellular solid acceptors and have widespread applications in the fields of pollutant degradation,biosynthesis,and hydrogen *** EAB screening methods can precisely measure the bacterial extracellular electron transfer ability,but they suffer from time-consuming and labor-intensive *** chemiluminescence technique is effective for the rapid detection of hemoglobin but has not been applied for EAB ***,we utilized a chemiluminescent assay to identify EAB through a multiheme c-type cytochrome(c-Cyt)triggered chemiluminescent *** multiheme c-Cyts-triggered chemiluminescence was conveniently determined by taking photographs with commercial smartphones and cloud-based *** acquired image signal shows a significant and linear relationship with the bacterial *** results of the chemiluminescence intensity triggered by different bacterial species with the proposed method are strongly associated with those of the microplate reading method(Pearson’s r of 0.9795;P<0.01)and dissimilatory Fe(Ⅲ)reduction method(Pearson’s r of 0.9628;P<0.01).Furthermore,this cloud-based and smartphone-assisted chemiluminescent assay is instrument-free and easy to operate,and results can be obtained within 2 *** findings demonstrate that the proposed method can effectively detect ***,it will be an alternative approach for EAB screening and can have promising applications in microbiology,environmental science,and bioenergy.

关键词： electroactive bacteria c-type cytochrome chemiluminescence cloud computing smartphone

Ground motion amplification pattern with TBM tunnels crossing soil-rock interface:Shaking table test

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Underground Space 2023年第5期12卷 202-217页

作者： Siming Li Roberto Cudmani Mingqing Xiao Zhiming Guo yong yuan College of Civil Engineering Tongji UniversityShanghai 200092China Department of Civil and Environmental Engineering Technical University of MunichMu¨nchen 81245Germany China Railway Siyuan Survey and Design Group Co. Ltd.Wuhan 430063China Public Works Construction Center Nanjing 210019China State Key Laboratory of Disaster Reduction in Civil Engineering Tongji UniversityShanghai 200092China

The current aseismic design has seldom considered the effect caused by underlain *** studies focused on the scenarios of tunnels embedded in homogeneous soil under transverse seismic *** paper aims to investigate the tunnel effect on the surface acceleration response in soil-rock strata by shaking table *** sets of excitations are employed and input along the shaking table in both transverse and longitudinal *** soil-rock site is classified as four micro-zones with varying conditions,to mount observation stations of acceleration *** characteristics of the four zones are identified by the transfer function(TF)method,and the tunnel effect on the ground acceleration response is obtained by comparing the spectral acceleration results between the free-field and ground-tunnel *** test results indicate that the tunnel effect varies with the site ***,a significant amplification effect is observed at the A4 zone,located on the soil deposit near the soil-rock ***,it is proved that the scattering waves generated at the interface and the standing waves trapped between the tunnel and upper ground surface account for the amplification,revealed by the discrepancies of the TF results and acceleration details between the free-field and ground-tunnel models.

关键词： Tunnel Soil-rock interface Seismic excitation Ground response Site characteristics

Connection of the prefabricated updeck of road tunnels by a short lap-spliced joint using ultra-high-performance fiber-reinforced concrete

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Frontiers of Structural and Civil Engineering 2023年第6期17卷 870-883页

作者： Hui WANG yong yuan Junnan QIU yuan XUE Guangzhou XIE Qian CHENG yuanchao DING Qing AI School of Naval Architecture Ocean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China College of Civil Engineering Tongji UniversityShanghai200092China Shanghai Chengtou Highway Group Co. Ltd.Shanghai200336China Shanghai Shentong Metro Group Co. Ltd.Shanghai201103China

Prefabricated internal structures of road tunnels,consisting of precast elements and the connections between them,provide advantages in terms of quality control and manufacturing ***,the limited construction space in tunnels creates challenges for on-site *** identify feasible connecting joints,flexural tests of precast straight beams connected by welding-spliced or lap-spliced reinforcements embedded in normal concrete or ultra-high-performance fiber-reinforced concrete(UHPFRC)are first performed and *** an improvement in the strength grade of the closure concrete for the lap-spliced joint,the failure of the beam transforms from a brittle splitting mode to a ductile flexural *** beam connected by UHPFRC100 with short lap-spliced reinforcements can achieve almost equivalent mechanical performance in terms of the bearing capacity,ductility,and stiffness as the beam connected by normal concrete with welding-spliced *** favorable solution is then applied to the connection of neighboring updeck slabs resting on columns in a double-deck *** applicability is validated by flexural tests of T-shaped joints,which,fail in a ductile fashion dominated by the ultimate bearing capacity of the precast elements,similar to the corresponding straight *** utilization of UHPFRC significantly reduces the required lap-splice length of reinforcements owing to its strong bonding strength.

关键词： UHPFRC prefabricated updeck road tunnel lap-spliced rebars flexural tests

Insights into carbon-based materials for catalytic dehydrogenation of low-carbon alkanes and ethylbenzene

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Frontiers of Chemical Science and Engineering 2023年第11期17卷 1623-1648页

作者： Sijia Xing Sixiang Zhai Lei Chen Huabin Yang Zhong-yong yuan School of Materials Science and Engineering Smart Sensing Interdisciplinary Science CenterNankai UniversityTianjin 300350China Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) Nankai UniversityTianjin 300071China

Direct dehydrogenation with high selectivity and oxidative dehydrogenation with low thermal limit has been regarded as promising methods to solve the increasing demands of light olefins and *** catalysts have shown remarkable performance for these reactions,such as Pt,CrOx,Co,ZrOx,Zn and *** with metal-based catalysts,carbon materials with stable structure,rich pore texture and large surface area,are ideal platforms as the catalysts and the supports for dehydrogenation *** this review,carbon materials applied in direct dehydrogenation and oxidative dehydrogenation reactions including ordered mesoporous carbon,carbon nanodiamond,carbon nanotubes,graphene and activated carbon,are summarized.A general introduction to the dehydrogenation mechanism and active sites of carbon catalysts is briefly presented to provide a deep understanding of the carbon-based materials used in dehydrogenation *** unique structure of each carbon material is presented,and the diversified synthesis methods of carbon catalysts are *** approaches for promoting the catalytic activity of carbon catalysts are elaborated with respect to preparation method optimization,suitable structure design and heteroatom *** regeneration mechanism of carbon-based catalysts is discussed for providing guidance on catalytic performance *** addition,carbon materials as the support of metal-based catalysts contribute to exploiting the excellent catalytic performance of catalysts due to superior structural *** the end,the challenges in current research and strategies for future improvements are proposed.

关键词： carbon materials dehydrogenation active sites mechanism catalytic performance support

Interactions between gas flow and reversible chemical reaction in porous media

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Journal of Central South University 2017年第5期24卷 1144-1154页

作者： JIANG yuan-yong XU Zeng-he ZHANG Meng-zhou BAI Li-yuan School of Resources and Civil Engineering Northeastern UniversityShenyang 110819China College of Applied Technology Liaoning Technical UniversityFuxin 123000China Environmental Monitoring Center Station of Tangshan City Tangshan 063000China

Taking into consideration the gas compressibility and chemical reaction reversibility, a model was developed to study the interactions between gas flow and chemical reaction in porous media and resolved by the finite volume method on the basis of the gas-solid reaction aA(g)+bB(s)cC(g)+dD(s).The numerical analysis shows that the equilibrium constant is an important factor influencing the process of gas-solid reaction. The stoichiometric coefficients, molar masses of reactant gas, product gas and inert gas are the main factors influencing the density of gas mixture. The equilibrium constant influences the gas flow in porous media obviously when the stoichiometric coefficients satisfy a/c≠1.

关键词： porous media compressible gas flow reversible chemical reaction interaction

Multiquadric Finite Difference (MQ-FD) Method and its Application

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Advances in Applied Mathematics and Mechanics 2009年第5期1卷 615-638页

作者： yong yuan Shan Chang Shu Ning Qin Department of Mechanical Engineering National University of Singapore10 Kent Ridge CrescentSingapore 119260Singapore Department of Mechanical Engineering University of SheffieldMappin StreetSheffield S13JDUnited Kingdom

The conventional finite difference(FD)schemes are based on the low order polynomial approximation in a local *** paper shows that when the polynomial approximation is replaced by the multiquadric(MQ)function approximation in the same region,a new FD method,which is termed as MQ-FD method in this work,can be *** paper gives analytical formulas of the MQ-FD method and carries out a performance study for its derivative approximation and solution of Poisson equation and the incompressible Navier-Stokes *** addition,the effect of the shape parameter c in MQ on the formulas of the MQFD method is *** approximation in one-dimensional space and Poisson equation in two-dimensional space are taken as model problems to study the accuracy of the MQ-FD ***,a lid-driven flow problem in a square cavity is simulated by the MQ-FD *** obtained results indicate that this method may solve the engineering problem very accurately with a proper choice of the shape parameter c.

关键词： MQ-FD method shape parameter central FD method

Seismic damage of mountain tunnels during the 5.12 Wenchuan earthquake

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Journal of Mountain Science 2016年第11期13卷 1958-1972页

作者： YU Hai-tao CHEN Jun-tao yuan yong ZHAO Xu Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of Technology Beijing 100124 China

A number of mountain tunnels suffered significant damage to various extent during the 2008 Wenchuan earthquake in *** ranging from small to heavy cracking was observed both at the portal and inside the tunnels,while some sections close to the faults completely collapsed.A summary of qualitative data collected from reports and papers is presented regarding the behavior of the 55 mountain tunnels near the epicenter during the *** on the seismic investigation and data collection of mountain tunnels,the tunnel damage is classified into six most common damage models involving cracking,spalling,shear failure,dislocation,pavement uplift and *** study and discussion are then carried out on the damage *** order to examine the influencing factors of the damage magnitude of the mountain tunnels,the correlations between epicentral distance,earthquake intensity,overburden depth,geological condition and damage levels are *** relationships between earthquake parameters and different damagemodels are developed and ***,suggestions are provided to improve the seismic resistance of mountain tunnels.

关键词： Wenchuan earthquake Mountain tunnels Damage model Influencing factors Seismic capacity