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Numerical modeling of 3D DC resistivity method in the mixed space-wavenumber domain

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Applied Geophysics 2021年第3期18卷 361-374,432,433页

作者： Dai Shi-Kun Ling Jia-Xuan Chen Qing-Rui Li Kun zhang qian-jiang Zhao Dong-Dong zhang Ying Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring Ministry of EducationSchool of Geosciences and Info-physicsCentral South UniversityChangsha410083China School of Earth Science and Technology Southwest Petroleum UniversityChengdu610500China School of Earth Sciences Guilin University of TechnologyGuilin541004China Nanjing Geological Survey Center of China Geological Survey Nanjing210016China

Forward modeling is the basis of inversion imaging and quantitative interpretation for DC resistivity ***,a numerical model of the DC resistivity method must be finely divided to obtain a highly accurate solution under complex conditions,resulting in a long calculation time and large ***,we propose a 3D numerical simulation method in a mixed space-wavenumber domain to overcome this *** partial differential equation about abnormal potential is transformed into many independent ordinary differential equations with different wavenumbers using a 2D Fourier transform along the x axis and y axis *** this way,a large-scale 3D numerical simulation problem is decomposed into several 1D numerical simulation problems,which significantly reduces the computational and storage *** addition,these ordinary 1D differential equations with different wavenumbers are independent of each other and high parallelelism of the *** are solved using a finite-element algorithm combined with a chasing method,and the obtained solution is modified using a contraction *** this method,the vertical direction is reserved as the spatial domain,then grid size can be determined flexibly based on the underground current density distribution,which considers the solution accuracy and calculation *** addition,for the first time,we use the contraction operator in the integral equation method to iterate the *** algorithm takes advantage of the high efficiency of the standard Fourier transform and chasing method,as well as the fast convergence of the contraction *** verified the accuracy of the algorithm and the convergence of the contraction *** with a volume integral method and goal-oriented adaptive finite-element method,the proposed algorithm has lower memory requirements and high computational efficiency,making it suitable for calculating a model with large-scale ***,differ

关键词： 3D DC numerical simulation a mixed space-wavenumber domain 2D Fourier transform contraction operator

Quick-scanning X-ray absorption fine structure beamline at SSRF

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Nuclear Science and Techniques 2024年第6期35卷 1-13页

作者： Yu Chen qian Gao Zheng jiang Jiong Li Shuo zhang Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei 230029China

The layout and characteristics of the hard X-ray spectroscopy beamline(BL11B)at the Shanghai synchrotron radiation facility are described ***11B is a bending-magnet beamline dedicated to conventional and millisecond-scale quick-scanning X-ray absorption fine *** is equipped with a cylindrical collimating mirror,a double-crystal monochromator comprising Si(111)and Si(311),a channel-cut quick-scanning Si(111)monochromator,a toroidal focusing mirror,and a high harmonics rejection *** can provide 5-30 keV of X-rays with a photon flux of~5×10^(11)photons/s and an energy resolution of~1.31×10^(-4)at 10 *** performance of the beamline can satisfy the demands of users in the fields of catalysis,materials,and environmental *** paper presents an overview of the beamline design and a detailed description of its performance and capabilities.

关键词： Bending magnet beamline X-ray absorption fine structure Quick-scanning XAFS In situ Synchrotron radiation

Research on the Generation Mechanism and Suppression Method of Aerodynamic Noise in Expansion Cavity Based on Hybrid Method

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Computer Modeling in Engineering & Sciences 2024年第6期139卷 2747-2772页

作者： Haitao Liu Jiaming Wang Xiuliang zhang Yanji jiang qian Xiao School of Mechanotronics and Vehicle Engineering East China Jiaotong UniversityNanchang330013China Suzhou Automotive Research Institue Tsinghua UniversitySuzhou215131China

The expansion chamber serves as the primary silencing structure within the exhaust ***,it can also act as a sound-emitting structure when subjected to *** article presents a hybrid method for numerically simulating and analyzing the unsteady flow and aerodynamic noise in an expansion chamber under the influence of airflow.A fluid simulation model is established,utilizing the Large Eddy Simulation(LES)method to calculate the unsteady flow within the expansion *** simulation results effectively capture the development and changes of the unsteady flow and vorticity inside the cavity,exhibiting a high level of consistency with experimental *** calculate the aerodynamic noise sources within the cavity,the flow field results are integrated using the method of integral interpolation and inserted into the acoustic *** acoustic analogy method is then employed to determine the aerodynamic noise *** acoustic simulation model is established,and the flow noise source is imported into the sound field grid to calculate the sound pressure at the far-field response *** calculated sound pressure levels and resonance frequencies show good agreement with the experimental *** address the issue of airflow regeneration noise within the cavity,perforated tubes are selected as a means of noise *** experimental platformfor airflow regeneration noise is constructed,and experimental samples are processed to analyze and verify the noise suppression effect of perforated tube expansion cavities under different airflow *** research findings indicate that the perforated tube expansion cavity can effectively suppress low-frequency aerodynamic noise within the cavity by impeding the formation of strong shear ***,the semi-perforated tube expansion cavity demonstrates the most effective suppression of aerodynamic noise.

关键词： Expansion cavity aerodynamic noise numerical simulation hybrid method perforated tube

Oxidative Dehydrogenation of Propane over Supported Nickel Single-Atom Catalyst

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Chinese Journal of Chemistry 2024年第4期42卷 370-376页

作者： qian zhang Xunzhu jiang Yangyang Li Yuanlong Tan Qike jiang Xiaoyan Liu Botao Qiao CAS Key Laboratory of Science and Technology on Applied Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalianLiaoning116023 China University of Chinese Academy of Sciences Beijing100049 China Dalian National Laboratory for Clean Energy Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalianLiaoning116023 China

Oxidative dehydrogenation of propane has been an ever-growing field for propylene production due to its exothermic properties,of which overoxidation is the major drawback,with CO and even CO_(2) as undesired *** the purpose of getting higher propylene selectivity as well as yield,herein,we report Ni single atoms supported on calcium aluminate as an efficient catalyst candidate for propane oxidative *** from higher valence states of Ni1 species,it shows 2—3 times as much propylene selectivity as that of Ni *** 14.2%C_(3)H_(6) yield with 47.3%propylene selectivity has been achieved on Ni single atom catalyst and a good stability during 20 h test can be obtained as well.

关键词： Oxidative dehydrogenation/Nickel Single-atom catalysts Propane Propylene selectivity

AFM probe for measuring~10^(−5)ultra-low friction coefficient:Design and application

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Friction 2024年第1期12卷 64-73页

作者： Yushan CHEN Liang jiang Linmao qian Tribology Research Institute State Key Laboratory of Traction PowerSouthwest Jiaotong UniversityChengdu 610031China

Superlubricity provides a novel approach to addressing friction and wear issues in mechanical ***,little is known regarding improving the atomic force microscope(AFM)friction coefficient measurement ***,this study established the theoretical formula for the AFM friction coefficient measurement and deduced the measurement ***,the formula was applied to the AFM probe with a rectangular cross-section *** measurement resolution is associated with the dimensional properties of the AFM probe,the mechanical properties of the cantilever material,the properties of the position-sensitive detector(PSD),and probably the anti-vibration performance of the *** is feasible to make the cantilever as short as possible and the tip as high as possible to improve the measurement *** AFM probe for measuring an ultra-low friction coefficient was designed and *** cantilever’s length,width,and thickness are 50,35,and 0.6μm,*** tip height is 23μ*** measurement resolution can reach 7.1×10^(−6) under the maximum normal ***,the AFM probe was applied to measure the superlubricity between graphene *** friction coefficient is 0.00139 under 853.08 *** work provides a promising method for measuring a~10^(−5) friction coefficient of superlubricity.

关键词： atomic force microscope(AFM) superlubricity friction coefficientμ probe

Metal-organic framework hybrid materials of ZIF-8/RGO for immobilization of D-amino acid dehydrogenase

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Nano Research 2024年第1期17卷 290-296页

作者： Hangbin Lei qian zhang Xiaoyan Xiang Liang jiang Shiyan Wang Lingxuan Duan Shizhen Wang Department of Chemical and Biochemical Engineering College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China Xiamen Key Laboratory of Synthetic Biotechnology Xiamen UniversityXiamen 361005China

Immobilization of D-amino acid dehydrogenase(DAADH)by the assembly of peptide linker was studied for the biosynthesis of *** material of zeolitic imidazolate framework-8(ZIF-8)combined with reduced graphene oxide(RGO)was applied for the immobilization of DAADH from Ureibacillus *** recovery rate of DAADH/ZIF-8/RGO was 165.6%.DAADH/ZIF-8/RGO remained 53.4%of its initial activity at 50°C for 10 h while the free enzyme was ***/ZIF-8/RGO maintained 70.5%activity in hyperalkaline solution with pH *** parameters indicated that DAADH/ZIF-8/RGO had greater affinity of phenylpyruvate as V_(max)/K_(m)of DAADH/ZIF-8/RGO was 1.27-fold than free *** seven recycles,the activity of DAADH/ZIF-8/RGO remained 64.3%.Furthermore,one-step separation and in situ immobilization of DAADH by ZIF-8/RGO/Ni was carried out with 1.5-fold activity *** peptide linker and metal-organic framework(MOF)immobilization,thermostability and activity of the immobilized DAADH were significantly improved.

关键词： D-Amino acid dehydrogenase immobilization metal-organic frameworks zeolitic imidazolate framework-8(ZIF-8) reduced graphene oxide

Full sexual maturity-cycle exposure to environmentally relevant concentrations of 17β-estradiol decreases reproductive capacity of zebrafish

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Journal of Environmental Sciences 2024年第3期137卷 580-592页

作者： Yongkang zhang Yuanjun jiang qian Sun Meng Li Sheng Chen Jingyu Liang Chunsheng Liu College of Fisheries Huazhong Agricultural UniversityWuhan 430070China School of Environmental Studies China University of GeosciencesWuhan 430074China

17β-Estradiol(E2)has been widely detected in natural water and treatment with E2 induces potential endocrine disrupting effects in ***,effects on fish fecundity and steroid system after treatment with environmentally relevant concentrations of E2 for the full sexual maturation cycle remain *** this study,zebrafish were treatment with 0,10 or100 ng/L E2 from embryo to adult stage,and effects on gonadal development and differentiation,steroid hormone levels,transcription of genes associated with the hypothalamic-pituitary-gonadal-liver(HPG)axis in adults and fertilization rate of offspring were *** results showed that treatment with E2 lead to increased number of feminization in *** females,E2 decreased cumulative amount of spawning and inhibited the maturation of *** males,E2 inhibited the maturation and motility of sperm,as well as decreased the movement speed of *** adverse effects on sperm might be responsible for the reduced fertilization observed in *** addition,treatment with E2 changed the levels of steroid hormones in zebrafish gonad and altered the transcriptional levels of genes associated with HPG axis,which is responsible for the regulation of germ cells maturation and gonadal development in ***,these results suggested that treatment with environmentally relevant concentrations of E2 for the full sexual maturity cycle resulted in adverse effects on reproduction in zebrafish.

关键词： Environmental estrogen Zebrafish Fecundity Gonadal development Endocrine disruption

Geobacter sulfurreducens promoted the biosynthesis of reduced graphene oxide and coupled it for nitrobenzene reduction

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Journal of Environmental Sciences 2024年第4期138卷 458-469页

作者： Shoujuan zhang Qi Liu Linrui Zhong Jianhong jiang Xiaozhe Luo Xingxin Hu qian Liu Yue Lu College of Environmental Science and Engineering Hunan UniversityChangsha 410082China Shenzhen Research Institute Hunan UniversityShenzhen 510082China Key Laboratory of Environment Biology and Pollution Control Hunan UniversityMinistry of EducationChangsha 410082China China Machinery International Engineering Design&Research Institute Co. LtdChangsha 410007China Hunan Engineering Research Center for Water Treatment Process&Equipment Changsha 410007China

In order to explore an efficient and green method to deal with nitrobenzene(NB)pollutant,reduced graphene oxide(r GO)as an electron shuttle was applied to enhance the extracellular electron transfer(EET)process of Geobacter sulfurreducens,which was a typical electrochemically active bacteria(EAB).In this study,r GO biosynthesis was achieved via the reduction of graphene oxide(GO)by *** PCA within 3 ***,the r GOPCA combining system completely reduced 50-200μmol/L of NB to aniline as end product within one *** characterization revealed that PCA cells were partly wrapped by rGO,and therefore the distance of electron transfer between strain PCA and r GO material was ***,the ID/IGof GO,r GO,and r GO-PCA combining system were 0.990,1.293 and 1.31,***,highest currents were observed in r GO-PCA-NB as 12.950μA/-12.560μA at -408 m V/156 m V,attributing to the faster electron transfer efficiency in EET ***,the NB reduction was mainly due to:(I)direct EET process from *** PCA to NB;(II)r GO served as electron shuttle and accelerated electron transfer to NB,which was the main degradation ***,the biosynthesis of r GO via GO reduction by Geobacter promoted the NB removal process,which provided a facile strategy to alleviate the problematic nitroaromatic pollution in the environment.

关键词： Reduced graphene oxide Geobacter Nitrobenzene Removal Extracellular electron transfer

Flow Loss Mechanism in a Supercritical Carbon Dioxide Centrifugal Compressor at Low Flow Rate Conditions

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Journal of Thermal Science 2024年第1期33卷 114-125页

作者： YANG Zimu jiang Hongsheng ZHUGE Weilin CAI Ruikai YANG Mingyang CHEN Haoxiang qian Yuping zhang Yangjun State Key Laboratory of Automotive Safety and Energy Tsinghua UniversityBeijing 100084China School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China

With the advantages of high efficiency and compact structure,supercritical carbon dioxide(sC02)Brayton cycles have bright prospects for development in energy conversion *** one of the core components of the power cycle,the centrifugal compressor tends to operate near the critical point(304.13 K,7.3773 MPa).Normally,the compressor efficiency increases as the inlet temperature *** the inlet temperature is close to the critical point,the density increases sharply as the temperature decreases,which results in quickly decreasing of volume flow rate and efficiency *** flow loss mechanism of the sCO_(2) compressor operating at low flow rate is studied in this *** fluid dynamics(CFD) simulations for sCO_(2)compressor were carried out at various inlet temperatures and various mass flow *** the sCO_(2)compressor operates at low volume flow rate,the flow loss is generated mainly on the suction side near the trailing edge of the *** flow loss is related to the counterclockwise vortexes generated on the suction side of the main *** vortexes are caused by the flow separation in the downstream region of the impeller passage,which is different from air compressors operating at low flow *** reason for this flow separation is that the effect of Coriolis force is especially severe for the sCO_(2) fluid,compared to the viscous force and inertial *** lower flow rates,with the stronger effect of Coriolis force,the direction of relative flow velocity deviates from the direction of radius,resulting in its lower radial *** lower radial relative flow velocity leads to severe flow separation on the suction side near the trailing edge of the main blade.

关键词： supercritical CO_(2) centrifugal compressor flow loss mechanism Coriolis force