检索结果-南通市图书馆

The fast method and convergence analysis of the fractional magnetohydrodynamic coupled flow and heat transfer model for the generalized second-grade fluid

在线全文

学校读者我要写书评

暂无评论

Science china mathematics 2024年第4期67卷 919-950页

作者： Xiaoqing chi Hui Zhang Xiaoyun Jiang School of mathematics and Statistics Shandong UniversityWeihai 264209China School of mathematics Shandong UniversityJinan 250100China

In this paper,we first establish a new fractional magnetohydrodynamic(mHD)coupled flow and heat transfer model for a generalized second-grade *** coupled model consists of a fractional momentum equation and a heat conduction equation with a generalized form of Fourier *** second-order fractional backward difference formula is applied to the temporal discretization and the Legendre spectral method is used for the spatial *** fully discrete scheme is proved to be stable and convergent with an accuracy of O(τ^(2)+N-r),whereτis the time step-size and N is the polynomial *** reduce the memory requirements and computational cost,a fast method is developed,which is based on a globally uniform approximation of the trapezoidal rule for integrals on the real *** strict convergence of the numerical scheme with this fast method is *** present the results of several numerical experiments to verify the effectiveness of the proposed ***,we simulate the unsteady fractional mHD flow and heat transfer of the generalized second-grade fluid through a porous *** effects of the relevant parameters on the velocity and temperature are presented and analyzed in detail.

关键词： fractional mHD coupled flow and heat transfer model generalized second-grade fuid fast method convergence analysis numerical simulation

Tomographic reconstruction of the Earth’s magnetosheath from multiple spacecraft:a theoretical study

在线全文

学校读者我要写书评

暂无评论

Earth and Planetary Physics 2024年第1期8卷 204-214页

作者： A.m.Jorgensen TianRan Sun Y.Huang L.Li R.Xu L.Dai chi Wang New mexico Institute of mining and Technology SocorroNMUSA National Space Science Center Chinese Academy of SciencesBeijing 100190China Tsinghua University Beijing 100084China

Following our earlier work on tomographic reconstruction of the magnetosheath soft X-ray emissions with superposed epoch analysis of many images recorded from a single spacecraft we now explore the instantaneous reconstruction of the magnetosheath and magnetopause using a few images recorded simultaneously from a few *** work is motivated by the prospect of possibly having two or three soft X-ray imagers in space in the coming years,and that many phenomena which occur at the magnetopause boundary,such as reconnection events and pressure pulse responses,do not lend themselves as well to superposed epoch *** the reconstruction is successful-which we demonstrate in this paper that it can be-this collection of imagers can be used to reconstruct the magnetosheath and magnetopause from a single image from each spacecraft,allowing for high time resolution *** this paper we explore the reconstruction using,two,three,and four *** show that the location of the subsolar point of the magnetopause can be determined with just two satellites,and that volume emissions of soft X-rays,and the shape of the boundary,can be reconstructed using three or more satellites.

关键词： magnetosheath tomography soft X-ray imaging SmILE

Efficient Preparation and Electrochemical Properties of BiOCl/Graphite by One-step Solvothermal method

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(materials Science) 2024年第3期39卷 651-657页

作者：门丽娟 FEI chi LIU An 陈春钰 ZHOU Jiankang JU Dianchun School of metallurgy Engineering Jiangsu University of Science and TechnologyZhangjiagang 215600China

We used the surface-pretreated graphite paper(Gp)as a carrier and loaded BiOCl with high selectivity to Cl^(-)on its surface by solvothermal method to form BiOCl@Gp *** morphology,structure,and composition of the materials were characterized by scanning electron microscopy and nitrogen adsorption/desorption,and the results showed that the spherical BiOCl particles were uniformly dispersed on the surface of the Gp,forming a mesoporous BiOCl@Gp composite with a specific surface area of 22.82 m^(2)/g and a pore volume of 0.043 cm3/***,cyclic voltammetry and electrochemical impedance spectroscopy were used to test the electrochemical properties of the composites,and the stability of BiOCl and the high conductivity of Gp were synergistic,the BiOCl@Gp exhibited a specific capacitance of 30.2 F·g^(-1) at a current density of 0.5 A·g^(-1),and the selectivity of the BiOCl@Gp materials for Cl^(-)was significantly higher than that of SO_(4)^(2-),NO_(2)^(-),and HCO_(3)^(-).Therefore,BiOCl@Gp composite electrode materials can be used for the selective adsorption of Cl^(-)in wastewater,in order to achieve efficient wastewater recycling.

关键词： solvothermal method bismuth oxychloride electrochemistry electrode materials

Assessing the Performance of a Dynamical Downscaling Simulation Driven by a Bias-Corrected CmIP6 Dataset for Asian Climate

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2024年第5期41卷 974-988页

作者： Zhongfeng XU Ying HAN meng-Zhuo ZHANG chi-Yung TAm Zong-Liang YANG Ahmed m.EL KENAWY Congbin FU Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China School of Atmospheric Sciences Nanjing UniversityNanjing 210093China Earth System Science Programme The Chinese University of Hong KongHong KongChina Department of Geological Sciences Jackson School of GeosciencesThe University of Texas at AustinAustinTexasUSA Instituto Pirenaico de Ecología Consejo Superior de Investigaciones Científicas(CSIC)Campus de Aula Dei1005Zaragoza 50059Spain Department of Geography Mansoura UniversityMansoura 35516Egypt

In this study,we aim to assess dynamical downscaling simulations by utilizing a novel bias-corrected global climate model(GCm)data to drive a regional climate model(RCm)over the Asia-western North Pacific *** simulations were conducted with a 25-km grid spacing for the period 1980–*** first simulation(WRF_ERA5)was driven by the European Centre for medium-Range Weather Forecasts Reanalysis 5(ERA5)dataset and served as the validation *** original GCm dataset(mPI-ESm1-2-HR model)was used to drive the second simulation(WRF_GCm),while the third simulation(WRF_GCmbc)was driven by the bias-corrected GCm *** bias-corrected GCm data has an ERA5-based mean and interannual variance and long-term trends derived from the ensemble mean of 18 CmIP6 *** demonstrate that the WRF_GCmbc significantly reduced the root-mean-square errors(RmSEs)of the climatological mean of downscaled variables,including temperature,precipitation,snow,wind,relative humidity,and planetary boundary layer height by 50%–90%compared to the WRF_***,the RmSEs of interannual-tointerdecadal variances of downscaled variables were reduced by 30%–60%.Furthermore,the WRF_GCmbc better captured the annual cycle of the monsoon circulation and intraseasonal and day-to-day *** leading empirical orthogonal function(EOF)shows a monopole precipitation mode in the WRF_*** contrast,the WRF_GCmbc successfully reproduced the observed tri-pole mode of summer precipitation over eastern *** improvement could be attributed to a better-simulated location of the western North Pacific subtropical high in the WRF_GCmbc after GCm bias correction.

关键词： bias correction multi-model ensemble mean dynamical downscaling interannual variability day-to-day variability validation

Theoretical screening of cooperative N-bridged dual-atom sites for efficient electrocatalytic nitrogen reduction with remolding insight

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第4期17卷 3413-3422页

作者： Huimei Chen Yan Yang chi Jiao Zhiwen Zhuo Junjie mao Yan Liu Key Laboratory of Functional molecular Solids Ministry of EducationCollege of Chemistry and Materials ScienceAnhui Normal UniversityWuhu 241002China

The electrocatalytic nitrogen reduction reaction(e-NRR)is a promising alternative method for the Haber–Bosch ***,it still faces many challenges in searching for high activity,stability,and selectivity catalysts and ascertaining the catalytic mechanism with complete ***,a series of graphene-based N-bridged dual-atom catalysts(m1-N-m2/NC)are systematically investigated via first-principle calculation and a high-throughput screening *** result unveils that N_(2) adsorption on m1-N-m2/NC in bridge-on adsorption mode can effectively break the scaling relationship on single-atom catalysts(SACs).moreover,V-N-Ru/NC and V-N-Os/NC are systematically screened out as promising e-NRR catalysts,with extremely low limiting potentials of-0.20 and-0.18 V,***,the adsorption site competition between*N_(2) and*H,as well as the competitive twin reactions of hydrogen evolution reaction(HER)on intermediates(N_(n)H_(m))during the e-NRR process,is systematically evaluated to form a remodeling insight for the reactions in mechanism,and the e-NRR of new proposed dual-atom catalysts(DACs)is strategically optimized for its high-efficiency performance potential via our remolding insight in e-NRR *** work provides new ideas and insights for the design and mechanism of e-NRR catalysts and an effective strategy for rapidly screening highly efficient e-NRR catalysts.

关键词： nitrogen reduction dual-atom catalysts high-throughput screening hydrogen evolution reaction density functional theory calculations

Transient long-range distance measurement by a Vernier spectral interferometry

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Photonics Research 2024年第6期12卷 1107-1114页

作者： LIANG XU KUN WANG CHEN LIU WENYING CHEN chi ZHANG XINLIANG ZHANG Wuhan National Laboratory for Optoelectronics Huazhong University of Science and TechnologyWuhan 430074China Optics Valley Laboratory Wuhan 430074China

Rapid and long-range distance measurements are essential in various industrial and scientific applications,and among them,the dual-comb ranging system attracts great attention due to its high ***,the tem-poral asynchronous sampling results in the tradeoff between frame rate and ranging precision,and the non-ambiguity range(NAR)is also limited by the comb cycle,which hinders the further advancement of the dual-comb ranging *** this constraint,we introduce a Vernier spectral interferometry to improve the frame rate and NAR of the ranging ***,leveraging the dispersive time-stretch technology,the dual-comb interferometry becomes spectral ***,the asynchronous time step is unlimited,and the frame rate is improved to 100 ***,dual-wavelength bands are introduced to implement a Vernier spectral interferometry,whose NAR is enlarged from 1.5 m to 1.5 ***,this fast and long-range system also demonstrated high precision,with a 22.91-nm Allan deviation over 10-ms averaging *** a result,the proposed Vernier spectral interferometry ranging system is promising for diverse applications that necessitate rapid and extensive distance measurement.

关键词： interferometry spectral system

Alternative technology for the recovery of butyl acetate with low concentration:high capacity adsorbent and high efficiency adsorption

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Green Chemical Engineering 2024年第2期5卷 236-244页

作者： chi ma Lihong Zhao Zhengxin mao Hao Su Qingfen Liu CAS Key Laboratory of Green Process and Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing100049China

Industrial pharmaceutical wastewater usually contains butyl acetate(BA)with a concentration of 1 wt%-7 wt%,and the traditional method for BA recovery is distillation with high energy *** method is developed to recover BA with low concentration for the high efficiency and low energy *** polar polyacrylate resins with macroporous structure of 233.1 nm and average particle size of about 526.5μm are successfully synthesized by suspension polymerization and used for the BA adsorption and *** maximum adsorption capacity reaches 171.1 mg g^(-1)with relative standard deviation(RSD)value of 0.2%,which is more than twice the results in the *** BA desorption rate is 97.0%at 100℃with RSD value of 0.4%,and the resins are beneficial to the reuse in the adsorption-desorption *** adsorption thermodynamics and kinetics are investigated,and the BA adsorption is a spontaneous and endothermic process with the increase of disorder *** process is mainly contributed by physical absorption and agree well with Freundlich model and pseudo-first-order adsorption kinetic *** adsorption method avoids boiling a large amount of wastewater and hopefully provides a novel alternative technology for the BA recovery.

关键词： Butyl acetate recovery Resin adsorption Desorption Thermodynamics Kinetics

A near-zero quiescent power breeze wake-up anemometer based on a rolling-bearing triboelectric nanogenerator

在线全文

学校读者我要写书评

暂无评论

microsystems & Nanoengineering 2024年第2期10卷 241-249页

作者： Xianpeng Fu Zhichao Jiang Jie Cao Zefang Dong Guoxu Liu meiling Zhu chi Zhang CAS Center for Excellence in Nanoscience Beijing Key Laboratory of Micro-nano Energy and SensorBeijing Institute of Nanoenergy and NanosystemsChinese Academy of SciencesBeijing101400China School of Nanoscience and Engineering University of Chinese Academy of SciencesBeijing100049China Center on Nanoenergy Research Guangxi Colleges and Universities Key Laboratory of Blue Energy and Systems IntegrationSchool of Physical Science&TechnologyGuangxi UniversityNanning530004China Institute of Intelligent Flexible mechatronics Jiangsu UniversityZhenjiang212013China College of Engineering Mathematics and Physical ScienceUniversity of ExeterExeterEX44QFUK

Wind sensors have always played an irreplaceable role in environmental information monitoring and are expected to operate with lower power consumption to extend service ***,we propose a breeze wake-up anemometer(B-WA)based on a rolling-bearing triboelectric nanogenerator(RB-TENG)with extremely low static *** B-WA consists of two RB-TENGs,a self-waking-up module(SWm),a signal processing module(SPm),and a wireless transmission *** two RB-TENGs are employed for system activation and wind-speed *** the ambient wind-speed exceeds 2 m/s,the wake TENG(W-TENG)and the SWm can wake up the system within 0.96 *** the same time,the SPm starts to calculate the signal frequency from the measured TENG(m-TENG)to monitor the wind speed with a sensitivity of 9.45 Hz/(m/s).After the wind stops,the SWm can switch off the B-WA within 0.52 s to decrease the system energy *** quiescent on-duty mode,the operating power of the B-WA is less than 30 nW,which can greatly extend the service lifetime of the *** integrating triboelectric devices and rolling bearings,this work has realized an ultralow quiescent power and self-waked-up wireless wind-speed monitoring system,which has foreseeable applications in remote weather monitoring,IoT nodes,and so on.

关键词： generator power service

manipulation of magnetocaloric and elastocaloric effects in Ni-mn-In alloys by lattice volume and magnetic variation:Effect of Co and Fe co-doping

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of materials Science & Technology 2024年第5期172卷 156-165页

作者： Xinzeng Liang chi Zhang Jing Bai Jianglong Gu Yudong Zhang Claude Esling Xiang Zhao Liang Zuo School of materials Science and Engineering Shenyang University of TechnologyShenyang 110870China Key Laboratory for Anisotropy and Texture of materials Northeastern UniversityShenyang 110819China School of Resources and materials Northeastern University at QinhuangdaoQinhuangdao 066004China State Key Laboratory of metastable materials Science and Technology Yanshan UniversityQinhuangdao 066004China Laboratoire d’Étude des microstructures et de mécanique des matériaux LEM3 CNRSUMR 7239University of Lorraine57045 MetzFrance

The effects of Co and Fe co-doping Ni-mn-In alloy on the phase stability,lattice parameters,mag-netic properties,and electronic structures are systematically investigated by using the first-principles *** indicate that Fe atoms replace the excess mn2 atoms by direct and indirect coex-istence(Fe→mn 2 and Fe→In→mn2);Co substitutes the Ni atoms by direct substitution(Co→Ni)for the Ni-mn-In *** austenites all exhibit the ferromagnetic(Fm)state for the studied *** Nm martensites are in the ferrimagnetic(FIm-1)state for the Ni_(2)mn_(1.5)In_(0.5),Ni_(2)mn_(1.25)In_(0.5)Fe 0.25,Ni_(1.75)mn_(1.5)In_(0.5)Co_(0.25),and Ni_(1.75)mn_(1.25)In_(0.5)Co_(0.25)Fe 0.25 alloys,while the other compositions are in the Fm *** phase stability of austenite and martensite decreases with increasing Co and Fe co-doping.A magnetic-structural coupling transition occurs at xmn_(1.5)In_(0.5)Co_(0.08)and Ni_(1.91)mn_(1.42)In_(0.5)Co_(0.08)Fe_(0.08)alloys exhibit an A→6m→Nm transformation,accompanied by a magnetic *** Co and Fe are co-doped,the hybridization strength between Co and Fe is greater than that between Co/Fe and *** enhancement of magnetocaloric and elastocaloric effects is favored by larger magnetization difference(△m)and lattice volume change(△V/V_(0)).Based on the calculated phase stability,magneto-structure coupling,△V/V 0 and c/a ratio,one can predict that the Ni_(2)-x mn_(1.5)-y In_(0.5)Co x Fe y alloy with Co content 0≤x≤0.25 and Fe content 0≤y≤0.05 is predicted to have good magneto-controlled functional behavior.

关键词： Ni-mn-In-Co-Fe Phase stability magnetocaloric effect Elastocaloric effect