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Modeling effects of alloying elements and heat treatment parameters on mechanical properties of hot die steel with back-propagation artificial neural network

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Journal of Iron and Steel Research International 2017年第12期24卷 1254-1260页

作者： Yong Liu Jing-chuan zhu Yong Cao School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001HeilongjiangChina National Key Laboratory for Metal Precision Hot Processing of Metals Harbin 150001HeilongjiangChina

Materials data deep-excavation is very important in materials genome *** order to carry out materials data deep-excavation in hot die steels and obtain the relationships among alloying elements,heat treatment parameters and materials properties,a 11×12×12×4 back-propagation（BP）artificial neural network（ANN）was set *** element contents,quenching and tempering temperatures were selected as input;hardness,tensile and yield strength were set as output *** ANN shows a high fitting *** effects of alloying elements and heat treatment parameters on the properties of hot die steel were studied using this *** results indicate that high temperature hardness increases with increasing alloying element content of C,Si,Mo,W,Ni,V and Cr to a maximum value and decreases with further increase in alloying element *** ANN also predicts that the high temperature hardness will decrease with increasing quenching temperature,and possess an optimal value with increasing tempering *** model provides a new tool for novel hot die steel design.

关键词： Back-propagation artificial neural network Hot die steel Alloying element Heat treatment

1-set-contractive perturbations of accretive operators in Menger PN-spaces

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Applied Mathematics(A Journal of Chinese Universities) 2012年第3期27卷 363-370页

作者： WU Zhao-qi zhu chuan-xi Department of Mathematics Nanchang UniversityNanchang 330031China

Based on the topological degree for 1-set-contractive fields established in [11], we discuss the 1-set-contractive perturbation and the existence of zero points for nonlinear equations with accretive mappings in Menge... 详细信息

关键词： topological degree 1-set-contractive perturbation accretive mapping.

Topological degree for 1-set-contractive fields in M-PN spaces and its applications

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Applied Mathematics(A Journal of Chinese Universities) 2010年第4期25卷 463-474页

作者： WU Zhao-qi zhu chuan-xi Department of Mathematics Zhejiang University Hangzhou 310027 China Department of Mathematics Nanchang University Nanchang 330031 China

In this paper, we define the topological degree for 1-set-contractive fields in PN spaces. Based on this, we obtain some new fixed point theorems for 1-set-contractive operators. As an application, we study the existe... 详细信息

关键词： PN-space 1-set-contractive operator topological degree fixed point theorem.

First-principles calculations of structural,elastic and electronic properties of(TaNb)0.67(HfZrTi)0.33 high-entropy alloy under high pressure

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International Journal of Minerals,Metallurgy and Materials 2020年第10期27卷 1405-1414页

作者： Zhi-sheng Nong Hao-yu Wang Jing-chuan zhu School of Materials Science and Engineering Shenyang Aerospace UniversityShenyang 110136China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China

To clarify the effect of pressure on a(TaNb)0.67(HfZrTi)0.33 alloy composed of a solid solution with a single body-centered-cubic crystal structure,we used first-principles calculations to theoretically investigate the structural,elastic,and electronic properties of this alloy at different *** results show that the calculated equilibrium lattice parameters are consistent with the experimental results,and that the normalized structural parameters of lattice constants and volume decrease whereas the total enthalpy differenceΔE and elastic constants increase with increasing ***(TaNb)0.67(HfZrTi)0.33 alloy exhibits mechanical stability at high pressures lower than 400 *** high pressure,the bulk modulus B shows larger values than the shear modulus G,and the alloy exhibits an obvious anisotropic feature at pressures ranging from 30 to 70 *** analysis of the electronic structures reveals that the atomic orbitals are occupied by the electrons change due to the compression of the crystal lattices under the effect of high pressure,which results in a decrease in the total density of states and a wider electron energy *** factor is favorable for zero resistance.

关键词： first-principles calculations elastic property electronic structure density of states high-entropy alloys high pressure

Cachazo-Svrcek-Witten rules for tree-level gluonic amplitudes revisited

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Science China(Physics,Mechanics & Astronomy) 2022年第4期65卷 20-31页

作者： Wen-Jie Zhang Jun-Bao Wu chuan-Jie zhu Center for Joint Quantum Studies and Department of Physics School of ScienceTianjin UniversityTianjin 300350China Peng Huanwu Center for Fundamental Theory Hefei 230026China College of Mathematics and Physics Science Hunan University of Arts and ScienceChangde 415000China

We provide a new proof of Cachazo-Svrcek-Witten rules for tree-level gluonic *** a key step,we explicitly demonstrate the cancellation of spurious poles originating from the maximally helicity violating vertices in these *** achieve this,we introduce specially-defined two-off-shell-line sub-amplitudes and examine their residues at spurious poles.

关键词： general properties of perturbation theory perturbative calculations dualities in gauge field theories

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Expedient Trifluoromethylacylation of Styrenes Enabled by Photoredox Catalysis

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Chinese Journal of Chemistry 2022年第1期40卷 59-64页

作者： Lu Wang Heng Zhang chuan zhu Chao Feng Technical Institute of Fluorochemistry(TIF) Institute of Advanced Synthesis(IAS)School of Chemistry and Molecular EngineeringNanjing Tech University30 South Puzhu RoadNanjingJiangsu 211816China

Herein,we disclosed a photoredox enabled protocol for trifluoromethylacylation of styrenes through a radical-carboanion cascade and subsequent *** a broad range of aldehydes and inexpensive Langlois reagent as acyl and CF3 precursor,respectively,the alkene motif could be readily converted into β-trifluoromethyl ketones in moderate to good yields and with excellent *** CF3,di-,mono-and non-fluorinated C-radicals were revealed amenable in this reaction,providing good opportunity for the construction of structurally diverse ketones of interest in pharmaceutical ***,the utility of this protocol was further demonstrated by successful extension to trifluoromethylarylation and-alkylation by employing arylcyanide or acrylates in place of carbonyls.

关键词： Trifluoromethylacylation Alkenes Photocatalysis CF_(3)radical Radical-polar crossover

Numerical study on transom stern ventilation and resistance of high-speed ship in calm water

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Journal of Hydrodynamics 2022年第5期34卷 864-875页

作者： Hui Wang Ren-chuan zhu Meng-xiao Gu Le Zha State Key Laboratory of Ocean Engineering School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China Marine Design and Research Institute of China Shanghai200011China

A transom stern is a common design feature for a high-speed *** the present study,the transom stern ventilation of NPL 3b,5b hull is investigated by three methods:H−H formula,Doctors’formula,and computational fluid dynamics(CFD)method at *** the CFD method,the ratios of the wave elevation and wetted area are used to determine the transom *** of results show that Doctors’formula is more accurate to calculate the critical transom draft Froude *** then a Rankine panel method(RPM)based on the high-order boundary element method incorporated the modified transom stern condition is implemented to evaluate the steady wave problem of a high-speed fishery patrol ship in calm ***,free-surface(FS)and double body(DB)simulations based on Star-CCM+are carried out to obtain the wave-making resistance and total *** results of the resistance and wave pattern around the fishery patrol ship computed by RPM show generally good agreement with experimental measurement and CFD *** results indicate that the developed Rankine panel method with transom condition could predict the resistance of high-speed displacement ships with good accuracy.

关键词： Transom ventilation computational fluid dynamics(CFD)method Rankine panel method(RPM) high-speed ship double body simulation resistance

Strong Approximations for a Kumar-Seidman Network under a Priority Service Discipline

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Acta Mathematicae Applicatae Sinica 2010年第4期26卷 587-596页

作者： Lin Wu chuan-xi zhu Yun-jiang Wu Department of Mathematics Nanchang UniversityNanchang330031China Department of Mathematics Xi'an Jiao Tong UniversityXi'anChina

In this paper,we derive the strong approximations for a four-class two station multi-class queuing network（Kumar-Seidman network） under a priority service *** a group,jobs are served in the order of arrival,that is,a first-in-first-out disciple,and among groups,jobs are served under a pre-emptiveresume priority *** show that if the input data（i.e.,the arrival and service processe） satisfy an approximation（such as the functional law-of-iterated logarithm approximation or the strong approximation）,the output data（the departure processes） and the performance measures（such as the queue length,the work load and the sojourn time process） satisfy a similar approximation.

关键词： Strong approximation diffusion approximation priority service discipline Kumar-Seidman network

An investigation on HOBEM in evaluating ship wave of high speed displacement ship

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Journal of Hydrodynamics 2019年第3期31卷 531-541页

作者： Xi Chen Ren-chuan zhu Ya-lan Song Ju Fan Marine Design & Research Institute of China Shanghai 200011 China State Key L aboratory of Ocean Engineering Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration School of Naval Architecture Ocean and Civil Engineering Shanghai Jiao Tong University Shanghai 200240 China

A practical numerical tool is developed to evaluate ship waves of high speed displacement ships on the basis of potential flow theory, in which high order boundary element method (HOBEM) based on biquadratic shape functions is applied to solve the boundary value problem. Since the sinkage and trim of ship at high speeds are notable, influences of ship attitude on wave drag are investigated and three kinds of models are used to evaluate them. To make the numerical approach highly efficient, an incomplete LU factorization preconditioner is adopted and incorporated with the restarted generalized minimal residual method GMRES (m) to solve the boundary integral equation. A corresponding Fortran code is developed and applied to evaluate ship waves of the Wigley hull and 4a model, a transom stem ship. Computations are performed for both monohulls and catamarans over a wide range of Froude numbers (Fr= 0.10-l.00). Numerical issues including mesh convergence and computational efficiency are investigated at first. Computed results of the wave drag, sinkage and trim show generally good agreement with experimental data. Reasonable wave patterns are obtained and physical phenomena that wake angle max, where the largest waves occur, would become narrow at high speeds is also captured by the present computations. Numerical results indicate the proposed method would be accurate and efficient to evaluate resistance for hull design of high speed displacement ship.

关键词： High speed ship ship waves HOBEM ILU-GMRES sinkage and trim