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Blow-up of Viscous Compressible Reactive Self-gravitating Gas

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Acta Mathematicae Applicatae Sinica 2012年第2期28卷 401-408页

作者： fei jiang Zhong TAN School of Mathematical Sciences Xiamen University Xiamen 361005 China Institute of Applied Physics and Computational Mathematics l~eijlng IUUUI~ L）hma

In this paper, we prove some results concerning blow-up of viscous compressible reactive （selfgravitating） flows when the initial density is compactly supported and the other initial value satisfy proper conditions. It extends the work of Xin and Cho to the case of viscous compressible reactive self-gravitating flows equations. We control the lower bound of second moment by total energy and obtain the precise relationship between the size of the support of initial density and the existence time.

关键词： compressible Naviver-Stokes equations smooth solution reactive self-gravitating gas

Nonlinear instability for nonhomogeneous incompressible viscous fluids

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Science China Mathematics 2013年第4期56卷 665-686页

作者： jiang fei jiang Song NI GuoXi College of Mathematics and Computer Science Fuzhou University Laboratory of Computational Physics Institute of Applied Physics and Computational Mathematics

We investigate the nonlinear instability of a smooth steady density profile solution to the threedimensional nonhomogeneous incompressible Navier-Stokes equations in the presence of a uniform gravitational field,including a Rayleigh-Taylor steady-state solution with heavier density with increasing height(referred to the Rayleigh-Taylor instability).We first analyze the equations obtained from linearization around the steady density profile *** we construct solutions to the linearized problem that grow in time in the Sobolev space H k,thus leading to a global instability result for the linearized *** the help of the constructed unstable solutions and an existence theorem of classical solutions to the original nonlinear equations,we can then demonstrate the instability of the nonlinear problem in some *** analysis shows that the third component of the velocity already induces the instability,which is different from the previous known results.

关键词： nonhomogeneous Navier-Stokes equations steady density profile Rayieigh-Taylor instability incompressible viscous flows

Bimetallic anchoring catalysis for C–H and C–C activation

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Science China Chemistry 2021年第11期64卷 1923-1937页

作者： jiang-fei Li Yu-Xin Luan Mengchun Ye State Key Laboratory and Institute of Elemento-Organic Chemistry College of ChemistryFrontiers Science Center for New Organic MatterNankai UniversityTianjin300071China

Following the age of directing group,anchoring catalysis starts coming to the center of the *** from the directinggroup strategy that needs a preinstalled directing group in substrates,anchoring catalysis relies on a reversible interaction between a substrate and a catalyst,which then directs metal to activate inert chemical *** reversible directing effect not only generates good site-and stereo-selectivity as traditional directing groups do but also eliminates the requirement of stoichiometric amounts of directing *** variously reported anchoring catalysis,coordinative bimetallic anchoring catalysis in general displays superior reactivity than others because coordinative bonding not only affords strong interaction of catalysts with substrates but also displays good compatibility with substrates and reaction *** recent years,big progress has been achieved for coordinative bimetallic anchoring *** review gave a detailed summary of this field,including catalyst development,catalyst types,reaction types and reaction mechanisms.

关键词： C–H activation C–C activation bimetallic catalysis enantioselective anchoring catalysis

Synthesis and Characterization of Tungsten Doped Vanadium Dioxide Nanopowders by Thermolysis

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Chinese Chemical Letters 2006年第10期17卷 1417-1420页

作者： Zi fei PENG Wei jiang Department of Chemistry Shanghai Normal University Shanghai 200234

As far as we known, with white powdery tungstic acid （WPTA） used as the dopant for the first time, tungsten-doped vanadium dioxide （VO2） nanopowders were synthesized through thermolysis at low temperature. The products were characterized by XRD, TEM and DSC. When WPTA was added into V205 （with W/V = 2 atom %）, the phase transition temperature （Tc） of VO2 decreased markedly from 67.15℃ to 26.46℃ after annealing at 500℃. Such a low Tc is beneficial to the application and development of smart windows materials.

关键词： Vanadium dioxide white powdery tungstic acid phase transition thermolysis

Study on neutron-gamma discrimination methods based on GMM-KNN and LabVIEW implementation

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Nuclear Science and Techniques 2024年第11期35卷 82-97页

作者： Ting-Meng Ding Yu-Hang jiang Xuan-Xi Wang Xiao-fei jiang Big Data and Information Engineering GuiZhou UniversityGuiyang 550025China

Machine learning algorithms are considered as effective methods for improving the effectiveness of neutron-gamma(n-γ)*** study proposed an intelligent discrimination method that combined a Gaussian mixture model(GMM)with the K-nearest neighbor(KNN)algorithm,referred to as ***,the unlabeled training and test data were categorized into three energy ranges:0–25 keV,25–100 keV,and 100–2100 ***,GMM-KNN achieved small-batch clustering in three energy intervals with only the tail integral Q_(tail) and total integral Q_(total) as the pulse ***,we selected the pulses with a probability greater than 99%from the GMM clustering results to construct the training ***,we improved the KNN algorithm such that GMM-KNN realized the classification and regression algorithms through the LabVIEW *** outputs of GMM-KNN were the category or regression *** proposed GMM-KNN constructed the training set using unlabeled real pulse data and realized n-γdiscrimination of ^(241)Am-Be pulses using the LabVIEW *** experimental results demonstrated the high robustness and flexibility of *** when using only 1/4 of the training set,the execution time of GMM-KNN was only 2021 ms,with a difference of only 0.13%compared with the results obtained on the full training ***,GMM-KNN outperformed the charge comparison method in terms of accuracy,and correctly classified 5.52%of the ambiguous *** addition,the GMM-KNN regressor achieved a higher figure of merit(FOM),with FOM values of 0.877,1.262,and 1.020,corresponding to the three energy ranges,with a 32.08%improvement in 0–25 *** conclusion,the GMM-KNN algorithm demonstrates accurate and readily deployable real-time n-γdiscrimination performance,rendering it suitable for on-site analysis.

关键词： n-discrimination GMM KNN LabVIEW Classification Regression

Initial alignment of compass based on genetic algorithm-particle swarm optimization

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Defence Technology（防务技术） 2020年第1期16卷 257-262页

作者： Yi-feng Liang Peng-fei jiang jiang-ning Xu Wen An Miao Wu College of Electrical Engineering Naval Univ.of EngineeringWuhan 430033China

The rapidity and accuracy of the initial alignment influence the performance of the strapdown inertial navigation system(SINS),compass alignment is one of the most important methods for initial *** selection of the parameters of the compass alignment loop directly affects the result of ***,the optimal parameters of the compass loop of different SINS are also different Traditionally,the alignment parameters are determined by experience and trial-and-error,thus it cannot ensure that the parameters are *** this paper,the Genetic Algorithm-Particle Swarm Optimization(GA-PSO) algorithm is proposed to optimize the compass alignment parameters so as to improve the performance of the initial alignment of strapdown *** experiment results showed that the GA-PSO algorithm can find out the optimal parameters of the compass alignment circuit quickly and accurately and proved the effectiveness of the proposed method.

关键词： Inertial alignment Genetic algorithm SINS Compass alignment

Electrically Driven Crosslinked Liquid Crystal Polymers

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Chinese Journal of Chemistry 2023年第21期41卷 2925-2938页

作者： Meng Wang Chuan-fei jiang Hong Yang School of Chemistry and Chemical Engineering State Key Laboratory of Digital Medical EngineeringSoutheast UniversityNanjingJiangsu211189 China

Crosslinked liquid crystal polymers(CLCPs)are smart materials that combine the anisotropy of liquid crystals(LCs)with the elasticity of *** subjected to external stimuli,they exhibit exceptional two-way shape memory *** the various stimuli,electrical energy has the advantages of cleanliness,stability,and high controllability;hence,it is widely used for controlling CLCP-based soft actuators,thus presenting potential for application in diverse,complex *** combining electrically driven mode and sensor equipment,precise control of CLCPs can be achieved,and the electrically driven CLCPs can accomplish more intricate and sophisticated *** study presents a comprehensive review of electrically driven CLCPs with various driving mechanisms,including the electroclinic effect of ferroelectric CLCPs,the reorganization of LC molecules,the Maxwell effect of dielectric CLCPs,and the Joule heating effect of electrothermally responsive CLCP *** addition,a detailed analysis of the applications of electrically driven CLCPs in various research fields is ***,the current challenges in the field of electrically driven CLCP technology are summarized,along with predictions for future prospects.

关键词： Liquid crystal polymers Stimuli-responsive polymers Electrothermal materials Energy conversion Soft actuators

Modeling heterogeneous chemical processes on aerosol surface

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Particuology 2010年第4期8卷 308-318页

作者： Junjun Deng Tijian Wang Li Liu fei jiang School of Atraospheric Sciences Nanjing University 22 Hankou Road Nanjing 210093 China Guizhou Institute of Mountainous Climate and Environment Guiyang 550002 China

To explore the possible impact of heterogeneous chemical processes on atmospheric trace components, a coupled box model including gas-phase chemical processes, aerosol thermodynamic equilibrium processes, and heterogeneous chemical processes on the surface of dust, black carbon （BC） and sea salt is set up to simulate the effects of heterogeneous chemistry on the aerosol surface, and analyze the primary factors affecting the heterogeneous processes. Results indicate that heterogeneous chemical processes on the aerosol surface in the atmosphere will affect the concentrations of trace gases such as H2O2, HO2, O3, NO2, NO3, HNO3 and SO2, and aerosols such as SO42-, NO3- and NH4＋. Sensitivity tests suggest that the magnitude of the impact of heterogeneous processes strongly depends on aerosol concentration and the surface uptake coefficients used in the box model. However, the impact of temperature on heterogeneous chemical processes is considerably less. The ＂renoxification＂ of HNO3 will affect the components of the troPosPhere such as nitrogen oxide and ozone.

关键词： Box model Dust BC Sea salt Heterogeneous chemistry

Editorial for the Special Issue on Active Control and Protection of Future Renewables-dominated Distribution Grid

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Chinese Journal of Electrical Engineering 2022年第2期8卷 1-2页

作者： fei jiang Rongwu Zhu Changsha University of Science&Technology China Harbin Institute of Technology ShenzhenChina

The planning of carbon emissions peak and carbon neutrality speeds up the revolution and modernization of electricity power system,which is characterized by the high penetration of renewables and power electronics as ***,the replacement of conventional fossil fuel-based thermal plants and the development of renewables-dominated grids have been undergoing in current world.

关键词： Active dominated neutral