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Using a Modified Soil-Plant-Atmosphere Scheme(MSPAS)to Simulate the Interaction between Land Surface Processes and Atmospheric Boundary Layer in Semi-Arid Regions 被引量:20
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作者 树华 乐旭 +1 位作者 胡非 刘辉志 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2004年第2期245-259,共15页
This paper uses a Modified Soil-Plant-Atmosphere Scheme (MSPAS) to study the interaction between land surface and atmospheric boundary layer processes. The scheme is composed of two main parts: atmospheric boundary la... This paper uses a Modified Soil-Plant-Atmosphere Scheme (MSPAS) to study the interaction between land surface and atmospheric boundary layer processes. The scheme is composed of two main parts: atmospheric boundary layer processes and land surface processes. Compared with SiB and BATS, which are famous for their detailed parameterizations of physical variables, this simplified model is more convenient and saves much more computation time. Though simple, the feasibility of the model is well proved in this paper. The numerical simulation results from MSPAS show good agreement with reality. The scheme is used to obtain reasonable simulations for diurnal variations of heat balance, potential temperature of boundary layer, and wind field, and spatial distributions of temperature, specific humidity, vertical velocity, turbulence kinetic energy, and turbulence exchange coefficient over desert and oasis. In addition, MSPAS is used to simulate the interaction between desert and oasis at night, and again it obtains reasonable results. This indicates that MSPAS can be used to study the interaction between land surface processes and the atmospheric boundary layer over various underlying surfaces and can be extended for regional climate and numerical weather prediction study. 展开更多
关键词 modified soil-plant-atmosphere scheme (MSPAS) land surface processes (LSP) atmospheric boundary layer
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Three-dimensional analysis of the modified sloping cooling/shearing process 被引量:7
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作者 Renguo Guan Luolian Zhang +2 位作者 Chao Wang Jinglin Wen Jianzhong Cui 《Journal of University of Science and Technology Beijing》 CSCD 2007年第2期146-150,共5页
A self-designed setup of modified sloping cooling/shearing process was made to prepare the semisolid Al-3wt%Mg alloy. A three-dimensional simulation model was established for the analysis of preparing the semisolid Al... A self-designed setup of modified sloping cooling/shearing process was made to prepare the semisolid Al-3wt%Mg alloy. A three-dimensional simulation model was established for the analysis of preparing the semisolid Al-3wt%Mg alloy. Through simulation and experiment, it is shown that the sloping angle of the plate greatly affects temperature and velocity distributions, and the temperature and velocity of the alloy at the exit of the sloping plate increase with the increase of the sloping angle. The alloy temperature decreases linearly from the pouring mouth to the exit. The alloy temperature at the exit increases obviously with the increase of pouring temperature. To prepare the semisolid Al-3wt%Mg alloy with good quality, the sloping angle θ=45° is reasonable, and the pouring temperature is suggested to be designed above 650-660℃ but under 700℃. 展开更多
关键词 semisolid alloy modified sloping cooling/shearing process simulation TEMPERATURE VELoCITY
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Enhanced biological nutrient removal in modified carbon source division anaerobic anoxic oxic process with return activated sludge pre-concentration 被引量:8
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作者 鲁骎 毋海燕 +1 位作者 李昊岩 杨殿海 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第6期1027-1034,共8页
A pilot-scale modified carbon source division anaerobic anoxic oxic(AAO) process with pre-concentration of returned activated sludge(RAS) was proposed in this study for the enhanced biological nutrient removal(BNR) of... A pilot-scale modified carbon source division anaerobic anoxic oxic(AAO) process with pre-concentration of returned activated sludge(RAS) was proposed in this study for the enhanced biological nutrient removal(BNR) of municipal wastewater with limited carbon source. The influent carbon source was fed in step while a novel RAS pre-concentration tank was adopted to improve BNR efficiency, and the effects of an influent carbon source distribution ratio and a RAS pre-concentration ratio were investigated. The results show that the removal efficiency of TN is mainly influenced by the carbon source distribution ratio while the TP removal relies on the RAS pre-concentration ratio. The optimum carbon source distribution ratio and RAS pre-concentration ratio are 60% and 50%, respectively, with an inner recycling ratio of 100% under the optimum steady operation of pilot test, reaching an average effluent TN concentration of 9.8 mg·L-1with a removal efficiency of 63% and an average TP removal efficiency of 94%. The mechanism of nutrient removal is discussed and the kinetics is analyzed. The results reveal that the optimal carbon source distribution ratio provides sufficient denitrifying carbon source to each anoxic phase, reducing nitrate accumulation while the RAS pre-concentration ratio improves the condition of anaerobic zone to ensure the phosphorus release due to less nitrate in the returned sludge. Therefore, nitrifying bacteria, denitrifying bacteria and phosphorus accumulation organisms play an important role under the optimum condition, enhancing the performance of nutrient removal in this test. 展开更多
关键词 modified AAo process Carbon source distribution ratio Returned activated sludge pre-concentration Biological nutrient removal
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Estimation of Energy Consumption in COREX Process Using a Modified Rist Operating Diagram 被引量:2
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作者 Wen-long ZHAN Keng WU +2 位作者 Zhi-jun HE Qi-hang LIU Xiao-juan WU 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2015年第12期1078-1084,共7页
Fuel consumption in the COREX-3000 process run in Baosteel is currently higher than the design index. Therefore, mass and heat balance equations for the COREX process were established using the basic principles in- cl... Fuel consumption in the COREX-3000 process run in Baosteel is currently higher than the design index. Therefore, mass and heat balance equations for the COREX process were established using the basic principles in- cluded in the Rist operating diagram for blast furnace (BF) as a reference. Thermodynamic calculations were then used to modify the Rist operating diagram so that it was suitable for the COREX process. The modified Rist operating dia- gram was then applied for the evaluation of metallization rate (MR) and fuel structure to reduce the energy consump- tion in the COREX process. The modified Rist operating diagram for the shaft furnace (SF) provided a nearly ideal value for the restriction point W when the metallization rate was increased, while the point P on the operating line for the melter gasifier (MG) moved upward due to reduction in the heat required in hearth. The feasibility of reduc- ing the energy consumption during the COREX process by changing the fuel structure was also demonstrated. 展开更多
关键词 modified Rist operating diagram metallization rate fuel structure energy consumption CoREX process
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Synthesis of CeO_2/fly ash cenospheres composites as novel photocatalysts by modified pyrolysis process 被引量:3
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作者 张进 王冰 +3 位作者 崔皓 李闯 翟建平 李琴 《Journal of Rare Earths》 SCIE EI CAS CSCD 2014年第12期1120-1125,共6页
A novel fly ash cenospheres(FACs)-supported CeO2 composite(CeO2/FACs) was successfully synthesized by the modified pyrolysis process.The prepared composites were characterized by X-ray diffraction(XRD), scanning... A novel fly ash cenospheres(FACs)-supported CeO2 composite(CeO2/FACs) was successfully synthesized by the modified pyrolysis process.The prepared composites were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM), X-ray photoelectron spectroscopy(XPS), and diffuse reflection spectra(DRS) techniques.XRD results indicated that the CeO2 film coated on cenospheres was a face-centered cubic structure.SEM images confirmed that the CeO2 film was relatively compact.XPS results showed that Ce was present as both Ce4+ and Ce3+ oxidation states in CeO2 film coated on FACs substrate.The bandgap of the composite was narrower compared with the pure CeO2.The as-prepared material exhibited good photocatalytic activity for the decolorization of methylene blue(MB) under visible light irradiation, and the first-order reaction rate constant(k) of 0.0028 min–1 for CeO2/FACs composite was higher than 0.0015 min–1 of pure CeO2.The fact that they floated on water meant that CeO2/FACs composites were easily recovered from water by filtration after the reaction.The recycling test revealed that the composites were quite stable during the MB photocatalytic decolorization.The CeO2/ FACs catalyst was therefore promising for practical use in the degradation of pollutants or water cleanup. 展开更多
关键词 Ceo2 fly ash cenospheres(FACs) photocatalysis modified pyrolysis process rare earths
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A novel multimode process monitoring method integrating LCGMM with modified LFDA 被引量:4
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作者 任世锦 宋执环 +1 位作者 杨茂云 任建国 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第12期1970-1980,共11页
Complex processes often work with multiple operation regions, it is critical to develop effective monitoring approaches to ensure the safety of chemical processes. In this work, a discriminant local consistency Gaussi... Complex processes often work with multiple operation regions, it is critical to develop effective monitoring approaches to ensure the safety of chemical processes. In this work, a discriminant local consistency Gaussian mixture model(DLCGMM) for multimode process monitoring is proposed for multimode process monitoring by integrating LCGMM with modified local Fisher discriminant analysis(MLFDA). Different from Fisher discriminant analysis(FDA) that aims to discover the global optimal discriminant directions, MLFDA is capable of uncovering multimodality and local structure of the data by exploiting the posterior probabilities of observations within clusters calculated from the results of LCGMM. This may enable MLFDA to capture more meaningful discriminant information hidden in the high-dimensional multimode observations comparing to FDA. Contrary to most existing multimode process monitoring approaches, DLCGMM performs LCGMM and MFLDA iteratively, and the optimal subspaces with multi-Gaussianity and the optimal discriminant projection vectors are simultaneously achieved in the framework of supervised and unsupervised learning. Furthermore, monitoring statistics are established on each cluster that represents a specific operation condition and two global Bayesian inference-based fault monitoring indexes are established by combining with all the monitoring results of all clusters. The efficiency and effectiveness of the proposed method are evaluated through UCI datasets, a simulated multimode model and the Tennessee Eastman benchmark process. 展开更多
关键词 Multimode process monitoring Discriminant local consistency Gaussian mixture model modified local Fisher discriminant analysis Global fault detection index Tennessee Eastman process
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Modified artificial neural network model with an explicit expression to describe flow behavior and processing maps of Ti2AlNb-based superalloy
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作者 Yan-qi Fu Qing Zhao +1 位作者 Man-qian Lv Zhen-shan Cui 《Journal of Iron and Steel Research International》 SCIE EI CSCD 2021年第11期1451-1462,共12页
The elevated-temperature deformation behavior of Ti2AlNb superalloy was observed by isothermal compression experiments in a wide range of temperatures(950–1200°C)and strain rates(0.001–10 s^(-1)).The flow behav... The elevated-temperature deformation behavior of Ti2AlNb superalloy was observed by isothermal compression experiments in a wide range of temperatures(950–1200°C)and strain rates(0.001–10 s^(-1)).The flow behavior is nonlinear,strongly coupled,and multivariable.The constitutive models,namely the double multivariate nonlinear regression model,artificial neural network model,and modified artificial neural network model with an explicit expression,were applied to describe the Ti2AlNb superalloy plastic deformation behavior.The comparative predictability of those constitutive models was further evaluated by considering the correlation coefficient and average absolute relative error.The comparative results show that the modified artificial network model can describe the flow stress of Ti2AlNb superalloy more accurately than the other developed constitutive models.The explicit expression obtained from the modified artificial neural network model can be directly used for finite element simulation.The modified artificial neural network model solves the problems that the double multivariate nonlinear regression model cannot describe the nonlinear,strongly coupled,and multivariable flow behavior of Ti2AlNb superalloy accurately,and the artificial neural network model cannot be embedded into the finite element software directly.However,the modified artificial neural network model is mainly dependent on the quantity of high-quality experimental data and characteristic variables,and the modified artificial neural network model has not physical meanings.Besides,the processing maps were applied to obtain the optimum processing parameters. 展开更多
关键词 modified artificial neural network model Ti2AlNb superalloy Double multivariate nonlinear regression model Explicit expression processing map
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Control for Modified University of Cape Town Process Using Oxidation-Reduction Potential in the Second Anoxic Zone
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作者 王晓玲 林英姿 +3 位作者 李娜 张芳 谢添 董利鹏 《Journal of Donghua University(English Edition)》 EI CAS 2013年第3期215-221,共7页
The aim of this work is to evaluate the feasibility of applying the technology of oxidation-reduction potential (ORP) control on the municipal wastewater treatment system for nitrogen and phosphorus removal. Meanwhi... The aim of this work is to evaluate the feasibility of applying the technology of oxidation-reduction potential (ORP) control on the municipal wastewater treatment system for nitrogen and phosphorus removal. Meanwhile the relation between the optimal ORP ( ORPopt ) and influent C/N ratio was evaluated, in which the influent chemical oxygen demand ( COD ) concentration was stabilized at (290 ± 10 ) mg/L, the influent total phosphorus (TP) concentration was stabilized at (7.0 ± 0.5 ) mg/L. The results indicated that: (1) the ORP in the second anoxic zone had effect on nitrogen and phosphorus removal capability, and the average percentages of phosphorus uptake in ANO2 zone ( ηa ) increased with increasing ORP, i. e. , increasing from 12. 0% at - 143 mV to 22.0%,30.0%,37.0%, and45.0% at -123, -111, -105 and -95 mV, respectively; (2) the ORPopt as function of influent C/N ratio could be calculated by the equation: y ffi 252. 73e〈 -x/3.39) _ 131.01 ; the maximum percentage of phosphorus uptake in ANO2 as function of the ORPopt could be calculated by the equation: y ffi -0.49e(x/15.58) + 1. 51. The ORPopt was the important process control parameter that must be optimized for operation of enhanced biological phosphorus removal ( EBPR ) system. Moreover, ORP sensor is very simple, and the industrial applications of this strategy is practical. 展开更多
关键词 modified University of Cape Town (MUCT) process NITRATE oxidation-reduction potential oRP) phosphorus uptake
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Enhancing synthetic vinasse treatment efficiency using an integrated UASB-Modified Bardenpho Process
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作者 Afsaneh Mazaheri Mohamad Reza Doosti Mohammad javad Zoqi 《Bioresources and Bioprocessing》 2024年第1期1431-1446,共16页
Vinasse poses considerable environmental problems due to its complex composition of organic matter,minerals,and toxic compounds.If discharged into the environment without treatment,it can cause adverse impacts on ecos... Vinasse poses considerable environmental problems due to its complex composition of organic matter,minerals,and toxic compounds.If discharged into the environment without treatment,it can cause adverse impacts on ecosystems.This research investigated the effectiveness of an integrated treatment system involving an upflow anaerobic sludge blanket(UASB)reactor and the modified Bardenpho process(MBP)for purifying synthetic vinasse.The study lasted for 167 days,during which the integrated UASB-MBP system processed untreated synthetic vinasse with organic loading rates(OLR)ranging from 1.6 to 12.5 kgCOD/m3 day.The UASB-MBP system impressively achieved a COD removal efficiency of 99.41%.Removal efficiencies of approximately 98.14,99.91,and 99.63%were also achieved for total nitrogen(TN),total phosphorus(TP)and total ammonium(NH4+-N),respectively.The final discharge was 51.06 mg/L.The concentrations of NH4+-N and TN in the outflow of the settlement tank were 0.8-1.2 mg/L and 5.1-7.9 mg/L,respectively.Optimal performance was achieved when the HRT and nitrate recycle ratio were 15.5 h and 200%,respectively.The temperature was kept in the mesophilic range(33-35°C)during the experiments.These results underscores the potential of the integrated UASB reactor and modified Bardenpho process to provide an effective and eco-friendly approach for concurrent removal of COD and nutrients from vinasse treatment,offering broad prospects for implementation in wastewater treatment. 展开更多
关键词 Wastewater treatment VINASSE Anaerobic treatment UASB reactor modified Bardenpho processes
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Modified constitutive model and workability of 7055 aluminium alloy in hot plastic compression 被引量:17
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作者 ZHANG Tao ZHANG Shao-hang +2 位作者 LI Lei LU Shi-hong GONG Hai 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第11期2930-2942,共13页
To obtain flow behavior and workability of 7055 aluminium alloy during hot deformation,hot compression tests at different temperatures and strain rates are conducted.True stress?strain curves of 7055 aluminium alloy u... To obtain flow behavior and workability of 7055 aluminium alloy during hot deformation,hot compression tests at different temperatures and strain rates are conducted.True stress?strain curves of 7055 aluminium alloy under different conditions are obtained and the flow stress increases with ascending strain rate and descending temperature.For Arrhenius constitutive equation,each material parameter is set as a constant,which will bring forth large error for predicting flow behavior.In this work,material parameters are fitted as a function of temperature or strain rate based on experimental results and a modified constitutive equation is established for more accurate prediction of flow behavior of 7055 aluminium alloy.The effects of temperature and strain rate on power dissipation and instability are analyzed to establish a processing map of 7055 aluminium alloy.The dominant deformation mechanism for microstructure evolution at different deformation conditions can be determined and high efficiency of power dissipation may be achieved from power dissipation map.Meanwhile,proper processing parameters to avoid flow instability can be easily acquired in instability map.According to the processing map,optimized processing parameters of 7055 aluminium alloy are temperature of 673?723 K and strain rate of 0.01?0.4 s^?1,during which its efficiency of power dissipation is over 30%.Finite element method(FEM)is used to obtain optimized parameter in hot rolling process on the basis of processing map. 展开更多
关键词 7055 aluminium alloy flow behavior modified constitutive equation processing map optimized parameters
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Elevated temperature wear behaviour of CeO_2 modified WC-12Co coating 被引量:2
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作者 Yan Liu Guiying Yang +3 位作者 Zongqiu Hang Hao Fu Naiyuan Xi Hui Chen 《Journal of Rare Earths》 SCIE EI CAS CSCD 2019年第6期673-678,共6页
With the service environment becoming more and more severe, WC-Co coatings are required to apply in high temperature wear condition. In the present study, the sliding wear tests of CeO_2 modified WC-12 Co coatings wer... With the service environment becoming more and more severe, WC-Co coatings are required to apply in high temperature wear condition. In the present study, the sliding wear tests of CeO_2 modified WC-12 Co coatings were conducted at temperature of 450, 550 and 650 ℃. The wear loss and friction coefficient were recorded. The morphologies of wear tracks were observed every 1 h to investigate the dynamic wear mechanisms. The results show that the volume wear loss decreases with temperature increasing.The lowest volume wear loss is obtained at the temperature of 650 ℃ due to oxide films generated in the process of wearing. The wear mechanism is different at the temperature of 450, 550 and 650 0 C. Micro cutting wear, abrasive wear and oxidation wear dominate the wear mechanism at 450, 550 and 650 ℃,respectively. Abrasive wear and oxidation wear are the wear mechanisms at various temperatures. 展开更多
关键词 CEo2 modified WC-12Co coating Dynamic process ELEVATED temperature wear mechanism RARE earths
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Formation of TiO2 Modified Film on Carbon Steel 被引量:2
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作者 LaizhouSONG ShizheSONG ZhimingGAO 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2004年第5期599-601,共3页
A new technique for preparing TiO2 modified film on carbon steel was accomplished by electroless plating and sol-gel composite process. The artificial neural network was applied to optimize the preparing condition of ... A new technique for preparing TiO2 modified film on carbon steel was accomplished by electroless plating and sol-gel composite process. The artificial neural network was applied to optimize the preparing condition of TiO2 modified film. The optimized condition for forming TiO2 modified film on carbon steel was that NiP plating for 50 min, dip-coating times as 4, heat treatment time for 2 h, and the molar ratio of complexing agent and Ti(OC4HZ9)4 kept 1.5:1. The results showed that TiO2 modified film have good corrosion resistance. The result conformed that it is feasible to design the preparing conditions of TiO2 modified film by artificial neural network. 展开更多
关键词 Electroless plating Sol-gel composite process Artificial neural network Tio2 modified film Corrosion resistance
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Catalytic Oxidation of Dimethyl Ether to Dimethoxymethane over Cs Modified H_3PW_(12)O_(40)/SiO_2 Catalysts 被引量:8
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作者 Qingde Zhang Yisheng Tan +3 位作者 Caihong Yang Yizhuo Han Jun Shamoto Noritatsu Tsubaki 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2007年第3期322-325,共4页
The attractive utilization route for one-step catalytic oxidation of dimethyl ether to dimethoxymethane was successfully carried out over the H3PW12O40(40%)/SiO2 catalyst, modified by Cs, K, Ni, and V. The Cs modifi... The attractive utilization route for one-step catalytic oxidation of dimethyl ether to dimethoxymethane was successfully carried out over the H3PW12O40(40%)/SiO2 catalyst, modified by Cs, K, Ni, and V. The Cs modification of H3PW12O40(40%)/SiO2 gave the most promising result of 20% dimethyl ether conversion and 34.8% dimethoxymethane selectivity. Dimethoxymethane could be synthe- sized via methoxy groups decomposed from dimethyl ether through the synergistic effect between the acid sites and the redox sites of Cs modified H3PW12O40(40%)/SiO2. 展开更多
关键词 dimethyl ether DIMETHoXYMETHANE catalytic oxidation Cs modified H3PW12o40/Sio2 XRD
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Physicochemical properties of a novel composite polymer electrolyte doped with vinyltrimethoxylsilane-modified nano-La_2O_3 被引量:3
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作者 肖围 李新海 +4 位作者 王志兴 郭华军 王接喜 黄思林 甘雷 《Journal of Rare Earths》 SCIE EI CAS CSCD 2012年第10期1034-1040,共7页
Nano-La2O3 was modified with the vinyltrimethoxylsilane by hydrolysis and a novel poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) based composite polymer electrolyte doped with the modified nano-La2O3... Nano-La2O3 was modified with the vinyltrimethoxylsilane by hydrolysis and a novel poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) based composite polymer electrolyte doped with the modified nano-La2O3 was prepared by phase inversion method. The physicochemical properties were studied by SEM, FT-IR, XRD, TG and electrochemical methods. The results of FT-IR indicated that the nano-La2O3 was successfully modified with vinyltrimethoxylsilane. The XRD analysis showed that the incorporation of modified nano-La2O3 into the polymer electrolyte membranes could effectively reduce the crystallinity of PVDF-HFP, and the characterizations also suggested that thermal stability and electrochemical stability window could reach to 382°C and 5.1V, respectively; the reciprocal temperature dependence of ionic conductivity followed Vogel-Tamman-Fulcher (VTF) relation, ionic conductivity at room temperature was up to 3.5×10-3S/cm and lithium ions transference number was up to 0.42; the interfacial resistance increased at initial value about353Ω/cm2 and reached a steady value about 559Ω/cm2 after 5d storage at 30°C. The fabricated Li/As-prepared electrolytes/LiCoO2 coin cell showed excellent rate and cycle performances. 展开更多
关键词 composite polymer electrolyte vinyltrimethoxylsilane modify nano-La2o3 rare earths
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Simulation of the plasticizing behavior of composite modified doublebase(CMDB)propellant in grooved calendar based on adaptive grid technology 被引量:3
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作者 Su-wei Wang Xiu-duo Song +6 位作者 Zong-kai Wu Lei Xiao Guang-pu Zhang Yu-bing Hu Ga-zi Hao Wei Jiang Feng-qi Zhao 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2021年第6期1954-1966,共13页
The frequent occurrence of safety accidents during the calendering process is caused by the flammable and explosive properties of composite modified double-base(CMDB)propellant.Optimization of process parameters with ... The frequent occurrence of safety accidents during the calendering process is caused by the flammable and explosive properties of composite modified double-base(CMDB)propellant.Optimization of process parameters with the aid of fluid simulation technology could effectively ensure the safety of the calendering process.To improve the accuracy of the simulation results,material parameters and model structure were corrected based on actual conditions,and adaptive grid technology was applied in the local mesh refinement.In addition,the rheological behavior,motion trajectories and heat transfer mechanisms of CMDB propellant slurry were studied with different gaps,rotational rates and temperatures of two rollers.The results indicated that the refined mesh could significantly improve the contour clarity of boundaries and simulate the characteristics of CMDB propellant slurry reflux movement caused by the convergent flow near the outlet.Compared with the gap,the increased rotational rate of roller could promote the reflux movement and intensify the shear flow of slurry inside the flow region by viscous shear dragging.Meanwhile,under the synergistic effect of contact heat transfer as well as convective heat exchange,heat accumulated near the outlet and diffused along the reflux movement,which led to the countercurrent heat dissipation behavior of CMDB propellant slurry.The plasticizing mechanism of slurry and the safety of calendering under different conditions were explored,which provided theoretical guidance and reference data for the optimization of calendering process conditions.Based on the simulation results,the safety of the CMDB propellant calendering process could be significantly improved with a few tests conducted during a short research and development cycle. 展开更多
关键词 Composite modified double base propellant Calendering process Fluid simulation Vortex flow0
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Pd catalysts supported on modified Zr_(0.5)Al_(0.5)O_(1.75) used for lean-burn natural gas vehicles exhaust purification 被引量:6
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作者 Hongyan Shang Yun Wang +1 位作者 Maochu Gong Yaoqiang Chen 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2012年第4期393-399,共7页
Composite supports Zr0.5Al0.5O1.75 modified by metal oxides, such as La2O3, ZnO, Y2O3 or BaO, were prepared by co-precipitation method, and palladium catalysts supported on the modified composite supports were prepare... Composite supports Zr0.5Al0.5O1.75 modified by metal oxides, such as La2O3, ZnO, Y2O3 or BaO, were prepared by co-precipitation method, and palladium catalysts supported on the modified composite supports were prepared by impregnation method. Their properties were characterized by X-ray diffraction (XRD), NH3 temperature-programmed desorption (NH3-TPD), He temperature-programmed reduction (He-TPR), N2 adsorption/desorption, and CO-chemisorption. The catalytic activity and the resistance to water poisoning of the prepared Pd catalysts were tested in a simulated exhaust gas from lean-burn natural gas vehicles with and without water vapor. The results demonstrated that the modified supports had an apparent effect on the performance of Pd catalysts, compared with the Pd catalyst supported on the unmodified ZrA1. The addition of ZnO or Y203 promoted the conversion of CH4. In the absence of water vapor, Pd/ZnZrA1 exhibited the best activity for CH4 conversion with the light-off temperature (Tso) of 275 ℃ and the complete conversion temperature (T90) of 314 ℃, respectively. However, in the presence of water vapor, Pd/YZrA1 was the best one over which the light-off temperature (Tso) of methane was 339 ℃ and the complete conversion temperature (T90) was 371 ℃. These results indicated that Pd catalyst supported on the modified composite ZrA1 support showed excellent catalytic activity at low temperature and high resistance to H20 poisoning for the exhaust purification of lean-burn natural gas vehicles. 展开更多
关键词 modified Zr0.5Al0.5o1.75 PALLADIUM lean-bum natural gas vehicle methane oxidation water vapor
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Preparation of the Ag_2O_2-PbO_2 Modified Electrode and Its Application towards Escherichia coli Fast Counting in Water 被引量:3
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作者 JingGU WenZHANG +3 位作者 YuFengYANG LeiZHENG ZiRongWU LiTongJIN 《Chinese Chemical Letters》 SCIE CAS CSCD 2005年第5期635-638,共4页
A novel nano crystalline Ag2O2-PbO2 film chemically modified electrode (CME) was prepared and the CME was characterized by X-ray diffractometer (XRD) and atomic force microscope (AFM). By chronoamperometry, the nano A... A novel nano crystalline Ag2O2-PbO2 film chemically modified electrode (CME) was prepared and the CME was characterized by X-ray diffractometer (XRD) and atomic force microscope (AFM). By chronoamperometry, the nano Ag2O2-PbO2 CME was used as bioelectro- chemical sensor to determine the population of Escherichia coli (E. coli) in water. Compared with conventional methods, it is found that the technique we used is fast and convenient in counting E. coli. 展开更多
关键词 Ag2o2-Pbo2 modified platinum electrode Escherichia coli fast counting.
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Preparation of Calcium Cross-linked Nano-Fe3O4 Modified Zeolite Microspheres for Cu^2+ Adsorption from Wastewater 被引量:2
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作者 WEI Junchong LONG Xuejun +4 位作者 WANG Jia TANG Zheng WANG Tingting KANG Hanyu LIANG Shuang 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2020年第6期1021-1030,共10页
Artificial zeolite was modified by nano-Fe3O4 for development of functional adsorbents.Subsequently,adsorbents such as calcium cross-linked nano-Fe3O4 microspheres (Ca-MS),calcium cross-linked nano-Fe3O4 modified zeol... Artificial zeolite was modified by nano-Fe3O4 for development of functional adsorbents.Subsequently,adsorbents such as calcium cross-linked nano-Fe3O4 microspheres (Ca-MS),calcium cross-linked nano-Fe3O4 modified zeolite microspheres (Ca-MZS) and iron cross-linked nano-Fe3O4 modified zeolite microspheres (Fe-MZS) were prepared and compared for their adsorption performance.The effects of adsorbent dosage,solution pH,initial concentration and ion content on the removal of Cu^2+ from wastewater are investigated,and the adsorption kinetics and isotherms for the adsorbent materials were analyzed.The experimental results indicate that for the initial concentration of Cu^2+ of 30 mg/L,the adsorption is noted to be most stable.The optimal initial pH for adsorbing Cu^2+ is observed to be 5.5.At an optimal dosage of Ca-MZS of 900 mg/L,the adsorption capacity is measured to be 28.25 mg/g,along with the removal rate of 72.49%.The addition of Na+ and K+ affects the adsorption of Cu^2+.For the Na^+ and K^+ concentration of 0.2 mmol/L,the Cu^2+ removal rate by Ca-MZS drops to 11.94% and 22.12%,respectively.As compared with the adsorbents such as Natural Zeolite (NZ),Ca-MS and Fe-MZS,Ca-MZS demonstrates the best removal effect in solution,where the removal rate reaches 84.27%,with the maximum adsorption capacity of 28.09 mg/g.The Cu^2+ adsorption kinetics of Ca-MZS is observed to follow the Elovich kinetic model,with the adsorption isotherm data fitting the Freundlich isotherm model by using the non-linear method. 展开更多
关键词 ADSoRBENT modified zeolite CU^2+ NANo-FE3o4 MICRoSPHERES
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Electrocatalytic oxidation of hydrazine on magnetic bar carbon paste electrode modified with benzothiazole and iron oxide nanoparticles: Simultaneous determination of hydrazine and phenol 被引量:1
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作者 Ali Benvidi Shahriar Jahanbani +1 位作者 Bibi-Fatemeh Mirjalili Reza Zare 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第4期549-560,共12页
A magnetic bar carbon paste electrode (MBCPE) modified with Fe3O4 magnetic nanoparticles (Fe3O4NPs) and 2‐(3,4‐dihydroxyphenyl) benzothiazole (DPB) for the electrochemical determina‐tion of hydrazine was de... A magnetic bar carbon paste electrode (MBCPE) modified with Fe3O4 magnetic nanoparticles (Fe3O4NPs) and 2‐(3,4‐dihydroxyphenyl) benzothiazole (DPB) for the electrochemical determina‐tion of hydrazine was developed. The DPB was firstly self‐assembled on the Fe3O4NPs, and the re‐sulting Fe3O4NPs/DPB composite was then absorbed on the designed MBCPE. The MBCPE was used to attract the magnetic nanoparticles to the electrode surface. Owing to its high conductivity and large effective surface area, the novel electrode had a very large current response for the electrocat‐alytic oxidation of hydrazine. The modified electrode was characterized by voltammetry, scanning electron microscopy, electrochemical impedance spectroscopy, infrared spectroscopy, and UV‐visible spectroscopy. Voltammetric methods were used to study the electrochemical behaviour of hydrazine on MBCPE/Fe3O4NPs/DPB in phosphate buffer solution (pH = 7.0). The MBCPE/Fe3O4NPs/DPB, acting as an electrochemical sensor, exhibited very high electrocatalytic activity for the oxidation of hydrazine. The presence of DPB was found to reduce the oxidation potential of hydrazine and increase the catalytic current. The dependence of the electrocatalytic current on the hydrazine concentration exhibited two linear ranges, 0.1–0.4 μmol/L and 0.7–12.0 μmol/L, with a detection limit of 18.0 nmol/L. Additionally, the simultaneous determination of hydrazine and phe‐nol was investigated using the MBCPE/Fe3O4NPs/DPB electrode. Voltammetric experiments showed a linear range of 100–470 μmol/L and a detection limit of 24.3 μmol/L for phenol, and the proposed electrode was applied to the determination of hydrazine and phenol in water samples. 展开更多
关键词 modified electrode Electerocatalytic oxidation HYDRAZINE PHENoL Magnetic bar modified carbon paste electrode Fe3o4 nanoparticle
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Direct Synthesis of Al_2O_3-modified Li(Ni_(0.5)Co_(0.2)Mn_(0.3))O_2 Cathode Materials for Lithium Ion Batteries 被引量:1
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作者 王启岁 ZHANG Changchun +2 位作者 XING Junlong YANG Maoping XIE Jia 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2018年第1期97-101,共5页
To improve the cyclic stability at high temperature and thermal stability, the spherical Al2O3-modified Li(Ni0.5Co0.2Mn0.3)O2 was synthesized by a modified co-precipitation method, and the physical and electrochemic... To improve the cyclic stability at high temperature and thermal stability, the spherical Al2O3-modified Li(Ni0.5Co0.2Mn0.3)O2 was synthesized by a modified co-precipitation method, and the physical and electrochemical properties were studied. The TEM images showed that Li(Ni0.5Co0.2Mn0.3)O2 was modified successfully with nano-Al2O3. The discharge capacity retention of Al2O3-modified Li(Ni0.5Co0.2Mn0.3)O2 maintained about 99% after 200 cycles at high temperature(55 ℃), while that of the bare one was only 86%. Also, unlike bare Li(Ni0.5Co0.2Mn0.3)O2, the Al2O3-modified material cathode exhibited good thermal stability. 展开更多
关键词 modified precipitation method layered cathode materials Al2o3- modified cyclic stability DSC
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