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Commuting Dual Toeplitz Operators on the Polydisk

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Chinese Quarterly Journal of Mathematics 2009年第1期24卷 63-68页

作者： cheng guo-zheng yu tao Department of Mathematics Zhejiang Normal University Jinhua 321004 China

We completely characterize commutativity of S and Sψ on La2(Dn)⊥ for bounded pluriharmonic symbols  and ψ on Dn, and prove that SSψ = Sψ if and only if  is analytic or ψˉ is analytic.

关键词： Bergman space dual Toeplitz operator pluriharmonic

Influence of hydrogen concentration on Fe_2O_3 particle reduction in fluidized beds under constant drag force

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International Journal of Minerals,Metallurgy and Materials 2015年第1期22卷 12-20页

作者： Lei guo Han Gao Jin-tao yu Zong-liang Zhang Zhan-cheng guo State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing

The fixed-gas drag force from a model calculation method that stabilizes the agitation capabilities of different gas ratios was used to explore the influence of temperature and hydrogen concentration on fluidizing duration, metallization ratio, utilization rate of reduction gas, and sticking behavior. Different hydrogen concentrations from 5vol%to 100vol%at 1073 and 1273 K were used while the drag force with the flow of N2 and H2 （N2：2 L·min^-1;H2：2 L·min^-1） at 1073 K was chosen as the standard drag force. The metallization ratio, mean reduc-tion rate, and utilization rate of reduction gas were observed to generally increase with increasing hydrogen concentration. Faster reduction rates and higher metallization ratios were obtained when the reduction temperature decreased from 1273 to 1073 K. A numerical relation among particle diameter, particle drag force, and fluidization state was plotted in a diagram by this model.

关键词： fluidized beds ferric oxide iron ores agglomeration hydrogen drag force

Influence of deformation zone length on bending radius of SS304 tubes with small diameters manufactured via free bending-based active motion

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Chinese Journal of Aeronautics 2023年第6期36卷 420-434页

作者： Shenghan HU cheng cheng Ali Abd EL-ATY Shuo zheng Xunzhong guo Chunmei LIU Jie tao College of Material Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 21ll00China Department of Materials Science and Engineering&RIAM Seoul National UniversityI-Gwanak-roGwanakguSeoul 08826Republic of Korea Mechanical Engineering Department Faculty of Engineering-HelwanHelwan UniversityCairo 11795Egypt

In three and six-axis free-bending equipment,the deformation zone length(A)is a fixed mechanical structure parameter modified when the relevant structure is redesigned and *** this study,a six degree of freedom(6-DOF)parallel mechanism was used as the control mechanism of the bending die,and a new method of changing the deformation zone length(A)was ***,an idealized geometric model of free bending-based active motion was ***,the influence of the deformation zone length(A)on the bending moment and the bending radius of the tube was *** addition,the finite element simulation and a kinematic model of free bending-based active motion controlled by the 6-DOF parallel mechanism were established,and bending processes of the SS304 tube with different deformation zone lengths were ***,the impact of the deformation zone length(A)on the bending radius,bending moment,wall thickness,and motion of the parallel mechanism were ***,experiments were carried out on the free-bending equipment based on the 6-DOF parallel *** verified the rules in the theoretical analysis,finite element simulation,and kinematic simulation.

关键词： Bending radius Deformation zone length 6-DOF parallel mechanism Free bending-based active motion Small diameter tube

Weakly nonlinear multi-mode Bell-Plesset growth in cylindrical geometry

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Chinese Physics B 2020年第11期29卷 406-411页

作者： Hong-yu guo tao cheng Ying-Jun Li State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and TechnologyBeijing 100083China School of Science China University of Mining and TechnologyBeijing 100083China

Bell-Plesset(BP)effect caused perturbation growth plays an important role in better understanding of characteristics of the convergence *** equations for multi-mode perturbation growth on a cylindrically convergent interface are *** second-order weakly nonlinear(WN)solutions for two-mode perturbations at the interface which is subject to uniformly radical motion are *** WN theory is consistent with the numerical result in terms of mode-coupling effect in converging Richtmyer-Meshkov *** mode-coupling effects will cause irregular deformation of the convergent *** mode-coupling behavior in convergent geometry depends on the mode number,Atwood number A and convergence ratio *** A=-1.0 at the interface results in larger perturbation growth than A=*** growth of generated perturbation modes from two similar modes at the initial stage are smaller than that from two dissimilar modes.

关键词： Bell-Plesset effect Rayleigh-Taylor instability inertial confinement fusion

Chain damage effects of multi-spaced plates by reactive jet impact

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Defence Technology（防务技术） 2021年第2期17卷 393-404页

作者： yuan-feng zheng cheng-hai Su Huan-guo guo Qing-bo yu Hai-fu Wang State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China

Chain damage is a new phenomenon that occurs when a reactive jet impacts and penetrates multispaced *** reactive jet produces mechanical perforations on the spaced plates by its kinetic energy(KE),and then results in unusual chain rupturing effects and excessive structural damage on the spaced plates by its deflagration *** the present study,the chain damage behavior is initially demonstrated by *** reactive liners,composed of 26 wt%Al and 74 wt%PTFE,are fabricated through a pressing and sintering *** reactive liner thicknesses of 0.08 CD,0.10 CD and 0.12 CD(charge diameter)are chosen to carry out the chain damage *** results show a chain rupturing phenomenon caused by reactive *** constant reaction delay time and the different penetration velocities of reactive jets from liners with different thicknesses result in the variation of the deflagration position,which consequently determines the number of ruptured plates behind the ***,the finite-element code AUTODYN-3D has been used to simulate the kinetic energy only-induced rupturing effects on plates,based on the mechanism of behind armor debris(BAD).The significant discrepancies between simulations and experiments indicate that one enhanced damage mechanism,the behind armor blast(BAB),has acted on the ruptured ***,a theoretical model is used to consider the BAB-induced enhancement,and the analysis shows that the rupturing area on aluminum plates depends strongly upon the KE only-induced pre-perforations,the mass of reactive materials,and the thickness of plates.

关键词： Reactive materials Reactive jet Chain damage Behind armor blast

Development and mechanism analysis of a highly efficient binder in pelletizing of ilmenite used in electric furnace

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Journal of Iron and Steel Research International 2018年第12期25卷 1232-1236页

作者： Feng Chen yu-feng guo tao Jiang Shuai Wang Fu-qiang zheng School of Minerals Processing and Bioengineering Central South UniversityChangsha 410083HunanChina

The development and mechanism of a highly efficient binder in pelletizing of ilmenite from Panzhihua,China,were *** shows that both the drop strength of green pellets and compressive strength of dried pellets were improved when using the mixtures of starch,NaOH and sodium silicate as the *** film was formed on the surface of particles as the function of sodium silicate,promoting the filling of gelatinized starch between the adhesive films to bond the particle *** drop strength of green pellet was 1.3 times/(pellet 700 mm),and the compressive strength of dried pellet of 250℃ was 1825 N/pellets when 0.5 wt%NaOH,1.0 wt% sodium silicate and 2.0 wt% starch were added as adhesive.

关键词： Binder Ilmenite Pelletizing Adhesive film Gelatinization

Gas-based reduction of vanadium titano-magnetite concentrate:behavior and mechanisms

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International Journal of Minerals,Metallurgy and Materials 2017年第1期24卷 10-17页

作者： yu-lei Sui yu-feng guo tao Jiang Xiao-lin Xie Shuai Wang Fu-qiang zheng School of Minerals Processing and Bioengineering Central South UniversityChangsha 410083China

The reduction of vanadium titano-magnetite pellets by H_2-CO at temperatures from 850 to 1050°C was investigated in this paper. The influences of pre-oxidation treatment, reduction temperature, and V_（H_2）/（V_（H_2）＋ VCO） on the metallization degree were studied. The results showed that pre-oxidation played a substantial role in the reduction of vanadium titano-magnetite pellets. During the reduction process, the metallization degree increased with increasing temperature and increasing V_（H_2） /（V_（H_2）＋ VCO）. The phase transformation of pre-oxidized vanadium titano-magnetite pellets during the reduction process under an H_2 atmosphere and a CO atmosphere was discussed, and the reduced samples were analyzed by scanning electron microscopy（SEM） in conjunction with back scatter electron（BSE） imaging. The results show that the difference in thermodynamic reducing ability between H_2 and CO is not the only factor that leads to differences in the reduction results obtained using different atmospheres. Some of Fe_（3-x）Ti_xO_4 cannot be reduced under a CO atmosphere because of the densification of particles＇ structure and because of the enrichment of Mg in unreacted cores. By contrast, a loose structure of particles was obtained when the pellets were reduced under an H_2 atmosphere and this structure decreased the resistance to gas diffusion. Moreover, the phenomenon of Mg enrichment in unreacted cores disappeared during H_2 reduction. Both the lower resistance to gas diffusion and the lack of Mg enrichment facilitated the reduction of vanadium titano-magnetite.

关键词： titano-magnetite ore reduction behavior mechanisms

Facile construction of Mxene-supported niobium hydride nanoparticles toward reversible hydrogen storage in magnesium borohydride

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Rare Metals 2024年第9期43卷 4387-4400页

作者： Ao Xia Jia-Guang zheng Qing-Bo Zhang yu-Gang Shu cheng-guo Yan Liu-Ting Zhang Zhan-Liang tao Li-Xin Chen School of Energy and Power Jiangsu University of Science and TechnologyZhenjiang 212003China Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) Nankai UniversityTianjin 300071China State Key Laboratory of Silicon and Advanced Semiconductor Materials School of Materials Science and EngineeringZhejiang UniversityHangzhou 310027China

The facile construction of nanoscale NbH_(x)supported by Ti_(3)C_(2)(NbH_(x)@Ti_(3)C_(2))was achieved using facile ball milling strategy to improve the hydrogen desorption kinetics and reversibility of magnesium borohydride(Mg(BH_(4))_(2)).The doping of 30 wt%NbH_(x)@Ti_(3)C_(2)catalyst reduced the onset dehydrogenation temperature of Mg(BH_(4))_(2)to 71.2℃.Additionally,the Mg(BH_(4))_(2)+30NbH_(x)@Ti_(3)C_(2)composite achieved remarkable hydrogen release of over 9.2 wt%at a temperature as low as 230℃,indicating unexpected dehydrogenation ***,the reversibility of NbH_(x)@Ti_(3)C_(2)doped Mg(BH_(4))_(2)was retained to more than 4.2 wt%after four cycles,which was increased by 68%compared to that of undoped Mg(BH_(4))_(2).The strong catalysis of NbH_(x)@Ti_(3)C_(2)catalyst could be attributed to the synergistic effect of NbH_(x)and Ti_(3)C_(2)in hydrogen spillover and ***_(x)acted as a"hydrogen pump"for effective hydrogen spillover,while Ti_(3)C_(2)created numerous diffusion channels for hydrogen dissolution and provided the active catalytic site to facilitate the re/dehydrogenation of Mg(BH_(4))_(2).

关键词： Hydrogen storage Magnesium borohydride Catalysts Mxene

Molecular Basis for Stereospecific Hydrolysis of Ethyl Mandelate by Thermophilic Esterase

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Chemical Research in Chinese Universities 2011年第5期27卷 841-844页

作者： ZHANG guo-yan tao Jin zheng Liang-yu CAO Shu-gui Key Laboratory for Molecular Enzymology and Engineering Ministry of Education College of Chemistry Jilin University Changchun 130012 P. R. China

The stereospecific hydrolysis of mandelate can be effectively catalyzed by hyperthermophilic acylpeptide esterase APE 1547（Aeropyrum pernix esterase 1547）. APE 1547 used in this reaction showed a remarkable stereodi-scrimination in favour of R-mandelic acid（99% e.e.） with an enantiomeric ratio E〉200. The results of computer simulation are consistent with the experimental results. It can be inferred that the R-substrate adopted a binding mode productive of the reaction due to the formation of the hydrogen bond at the active site of APE 1547.

关键词： Hyperthermophilic acylpeptide esterase Biocatalyst Stereospecific hydrolysis Mandelic acid Computer simulation