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热处理对316L钢/Inconel625镍基合金双金属增材结构件微观组织与力学性能的影响
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作者 王天琪 李浩然 +1 位作者 刘海华 李晨东 《金属热处理》 北大核心 2026年第1期207-213,共7页
采用基于冷金属过渡焊的电弧快速成形技术制备得到316L-Inconel625双金属增材结构件,研究了固溶处理、时效处理以及固溶+时效处理对双金属结构件微观组织与力学性能的影响。结果表明:沉积态试样316L钢侧的组织主要为等轴奥氏体晶粒;Inco... 采用基于冷金属过渡焊的电弧快速成形技术制备得到316L-Inconel625双金属增材结构件,研究了固溶处理、时效处理以及固溶+时效处理对双金属结构件微观组织与力学性能的影响。结果表明:沉积态试样316L钢侧的组织主要为等轴奥氏体晶粒;Inconel625合金侧组织为柱状树枝晶,基体组织为γ-(Fe,Ni)固溶体,并且在晶界上存在大量Laves相。固溶处理后,Inconel625合金侧的Laves相溶解,基体中Nb,Mo元素含量提升。同时通过EBSD观察到316L钢侧奥氏体晶粒发生再结晶,晶粒长大并且伴有退火孪晶。固溶+时效处理后的双金属结构件在室温下的抗拉强度与屈服强度较沉积态有所降低,但是塑性大幅提升,且在600℃高温下强度与塑性协同提升,抗拉强度达到353 MPa,伸长率达到45.5%。 展开更多
关键词 双金属增材制造 固溶处理 时效处理 显微组织 力学性能
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Solutions to SU(n+1)Toda systems with cone singularities via toric curves on compact Riemann surfaces
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作者 Jingyu Mu Yiqian Shi and Bin Xu 《中国科学技术大学学报》 北大核心 2025年第5期2-13,1,I0001,共14页
On a compact Riemann surface with finite punctures P_(1),…P_(k),we define toric curves as multivalued,totallyunramified holomorphic maps to P^(n)with monodromy in a maximal torus of PSU(n+1).Toric solutions to SU(n+1... On a compact Riemann surface with finite punctures P_(1),…P_(k),we define toric curves as multivalued,totallyunramified holomorphic maps to P^(n)with monodromy in a maximal torus of PSU(n+1).Toric solutions to SU(n+1)Todasystems on X\{P_(1);…;P_(k)}are recognized by the associated toric curves in.We introduce character n-ensembles as-tuples of meromorphic one-forms with simple poles and purely imaginary periods,generating toric curves on minus finitelymany points.On X,we establish a correspondence between character-ensembles and toric solutions to the SU(n+1)system with finitely many cone singularities.Our approach not only broadens seminal solutions with two conesingularities on the Riemann sphere,as classified by Jost-Wang(Int.Math.Res.Not.,2002,(6):277-290)andLin-Wei-Ye(Invent.Math.,2012,190(1):169-207),but also advances beyond the limits of Lin-Yang-Zhong’s existencetheorems(J.Differential Geom.,2020,114(2):337-391)by introducing a new solution class. 展开更多
关键词 SU(n+1)Toda system regular singularity unitary curve toric solution character ensemble
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MEROMORPHIC SOLUTIONS OF CERTAIN TYPES OF DIFFERENTIAL EQUATIONS WITH K EXPONENTIAL TERMS
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作者 Minfeng CHEN Meili LIANG Zongsheng GAO 《Acta Mathematica Scientia》 2025年第3期1155-1168,共14页
In this article,we study the meromorphic solutions of the following non-linear differential equation■where n and k are integers with n≥k≥3,P_(d)(z,f)is a differential polynomial in f of degree d≤n−1,p′js andα′j... In this article,we study the meromorphic solutions of the following non-linear differential equation■where n and k are integers with n≥k≥3,P_(d)(z,f)is a differential polynomial in f of degree d≤n−1,p′js andα′js are non-zero constants.We obtain the expressions of meromorphic solutions of the above equations under some restrictions onα′js.Some examples are given to illustrate the possibilities of our results. 展开更多
关键词 meromorphic solution non-linear differential equation Nevanlinna theory ex-ponential differential polynomial
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∑-Shaped Connected Component of Positive Solutions for One- Dimensional Prescribed Mean Curvature Equation in Minkowski Space
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作者 QI Tiaoyan LU Yanqiong 《Wuhan University Journal of Natural Sciences》 2025年第3期241-252,共12页
In this work,we demonstrate that the existence of an Z-shaped connected component within the set of positive solutions for the one-dimensional prescribed mean curvature equation in Minkowski space■with boundary condi... In this work,we demonstrate that the existence of an Z-shaped connected component within the set of positive solutions for the one-dimensional prescribed mean curvature equation in Minkowski space■with boundary conditions having parameter in two cases f(O)=0 and f(0)>0 by using upper and lower solution method,where λ>0 is a parameter,f∈C^(2)([0,∞),R)is monotonically increasing and lim_(μ→1)^(f(u)/1-u=0,h∈C^(1)([0,1],(0,∞))is a nonincreasing function and h(t)>1. 展开更多
关键词 boundary conditions with parameters positive solutions the upper and lower solution method asymptotic property
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A POSITIVE SOLUTION FOR QUASILINEAR SCHRÖDINGER-POISSON SYSTEM WITH CRITICAL EXPONENT
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作者 Lanxin HUANG Jiabao SU 《Acta Mathematica Scientia》 2025年第4期1247-1264,共18页
In this paper,we study the quasilinear Schrödinger-Poisson system with critical Sobolev exponent {-△_(p)u+|u|^(p-2)u=|u|^p^(*-2)u+ph(x)|u|^(q-2)u in R^(3),-△Φt(x)|u|^(p) in R^(3) where μ>0,3/2<p<3,p... In this paper,we study the quasilinear Schrödinger-Poisson system with critical Sobolev exponent {-△_(p)u+|u|^(p-2)u=|u|^p^(*-2)u+ph(x)|u|^(q-2)u in R^(3),-△Φt(x)|u|^(p) in R^(3) where μ>0,3/2<p<3,p≤q<p^(3)=3p/3-p and △_(p)u=div(|▽u|^(p-2)▽u)Under certain assumptions on the functions l and h, we employ the mountain pass theorem to establish the existence of positive solutions for this system. 展开更多
关键词 quasilinear Schrodinger-Poisson system variational methods critical growth positive solution
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The Tamed Euler Method for Random Periodic Solution of Semilinear SDEs with One-sided Lipschitz Coefficient
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作者 GUO Yujia NIU Yuanling 《数学理论与应用》 2025年第2期22-39,共18页
This paper aims to investigate the tamed Euler method for the random periodic solution of semilinear SDEs with one-sided Lipschitz coefficient.We introduce a novel approach to analyze mean-square error bounds of the n... This paper aims to investigate the tamed Euler method for the random periodic solution of semilinear SDEs with one-sided Lipschitz coefficient.We introduce a novel approach to analyze mean-square error bounds of the novel schemes,without relying on a priori high-order moment bound of the numerical approximation.The expected order-one mean square convergence is attained for the proposed scheme.Moreover,a numerical example is presented to verify our theoretical analysis. 展开更多
关键词 Tamed Euler method Random periodic solution one-sided Lipschitz coefficient Order-one mean square convergence
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All entire solutions of Fermat type difference-differential equations of one variable
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作者 XU Ling LUO Run-zi CAO Ting-bin 《Applied Mathematics(A Journal of Chinese Universities)》 2025年第3期509-522,共14页
The main purpose of this paper is to try to find all entire solutions of the Fermat type difference-differential equation[p1(z)f(z+c)]^(2)+[p2(z)f(z)+p3(z)f′(z)]^(2)=p(z);or[p1(z)f(z)]^(2)+[p2(z)f′(z)+p3(z)f(z+c)]^(... The main purpose of this paper is to try to find all entire solutions of the Fermat type difference-differential equation[p1(z)f(z+c)]^(2)+[p2(z)f(z)+p3(z)f′(z)]^(2)=p(z);or[p1(z)f(z)]^(2)+[p2(z)f′(z)+p3(z)f(z+c)]^(2)=p(z)or[p1(z)f′(z)]^(2)+[p2(z)f(z+c)+p3(z)f(z)]^(2)=p(z);where c is a nonzero complex number,p1;p2 and p3 are polynomials in C satisfying p1p3■0;and p is a nonzero irreducible polynomial in C. 展开更多
关键词 difference equations difference-differential equation Fermat type equation entire solutions
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The N-soliton solutions of the three-component coupled nonlinear Hirota equations based on Riemann-Hilbert method
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作者 Xin Wang Zhi-Hui Zhang 《Chinese Physics B》 2025年第9期10-20,共11页
In order to more accurately and effectively consider the propagation process of solitons in electromagnetic pulse waves and make full use of wavelength division multiplexing,we study a class of high-order three-compon... In order to more accurately and effectively consider the propagation process of solitons in electromagnetic pulse waves and make full use of wavelength division multiplexing,we study a class of high-order three-component Hirota equations by the Riemann-Hilbert method.Under zero boundary conditions and given initial conditions q_(j)(x,0),the N-soliton solutions of the equations are obtained by constructing and solving Riemann-Hilbert problems based on matrix spectral problem.Specifically,we discuss the cases of N=1,2,analyze the dynamical properties of 1-soliton and 2-soliton solutions through numerical simulations,and summarize the effect of integrable perturbations and spectral parameters on soliton motion. 展开更多
关键词 coupled Hirota equation soliton solutions Riemann-Hilbert problem matrix spectral problem
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High Energy Normalized Solutions for the Schrodinger Equations with Exponential Critical Growth
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作者 ZHANG Xiao-cang XULi-ping 《Chinese Quarterly Journal of Mathematics》 2025年第1期1-19,共19页
In this paper,we study high energy normalized solutions for the following Schr?dinger equation{-Δu+V(x)u+λu=f(u),in R^(2),∫_(R^(2))|u|^(2)dx=c,where c>0,λ∈R will appear as a Lagrange multiplier,V(x)=ω|x|2 rep... In this paper,we study high energy normalized solutions for the following Schr?dinger equation{-Δu+V(x)u+λu=f(u),in R^(2),∫_(R^(2))|u|^(2)dx=c,where c>0,λ∈R will appear as a Lagrange multiplier,V(x)=ω|x|2 represents a trapping potential,and f has an exponential critical growth.Under the appropriate assumptions of f,we have obtained the existence of normalized solutions to the above Schr?dinger equation by introducing a variational method.And these solutions are also high energy solutions with positive energy. 展开更多
关键词 High energy normalized solutions Schrodinger equation Trapping potential Exponential critical growth Variational method
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General analytical solutions for one-dimensional diffusion of degradable organic contaminant in the multi-layered media containing geomembranes
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作者 JIANG Wen-hao GE Shang-qi LI Jiang-shan 《Journal of Central South University》 2025年第10期3895-3910,共16页
In practical engineering construction,multi-layered barriers containing geomembranes are extensively applied to retard the migration of pollutants.However,the associated analytical theory on pollutants diffusion still... In practical engineering construction,multi-layered barriers containing geomembranes are extensively applied to retard the migration of pollutants.However,the associated analytical theory on pollutants diffusion still needs to be further improved.In this work,general analytical solutions are derived for one-dimensional diffusion of degradable organic contaminant(DOC)in the multi-layered media containing geomembranes under a time-varying concentration boundary condition,where the variable substitution and separated variable approaches are employed.These analytical solutions with clear expressions can be used not only to study the diffusion behaviors of DOC in bottom and vertical composite barrier systems,but also to verify other complex numerical models.The proposed general analytical solutions are then fully validated via three comparative analyses,including comparisons with the experimental measurements,an existing analytical solution,and a finite-difference solution.Ultimately,the influences of different factors on the composite cutoff wall’s(CCW,which consists of two soil-bentonite layers and a geomembrane)service performance are investigated through a composite vertical barrier system as the application example.The findings obtained from this investigation can provide scientific guidance for the barrier performance evaluation and the engineering design of CCWs.This application example also exhibits the necessity and effectiveness of the developed analytical solutions. 展开更多
关键词 general analytical solutions degradable organic contaminant diffusion behavior multi-layered media containing geomembranes composite barrier system
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YOANTION:Pioneering advanced dyeing&finishing solutions
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《China Textile》 2025年第5期59-59,共1页
Yoantion Industrial INC.,LTD.is a listed company Stock Code 301053 specializing in high-end dyeing and finishing equipment.It serves as the vice president unit of the China Textile Machinery Association and the vice p... Yoantion Industrial INC.,LTD.is a listed company Stock Code 301053 specializing in high-end dyeing and finishing equipment.It serves as the vice president unit of the China Textile Machinery Association and the vice president unit of the China Dyeing and Printing Association.The company has been awarded numerous honors including National High-tech Enterprise and National Stenter Development Base.Its leading products are well-received both domestically and internationally. 展开更多
关键词 advanced dyeing China Textile Machinery Association vice president unit national stenter development base finishing solutions finishing equipment national high tech enterprise high end dyeing
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Facile synthesis of Na_(0.9)Mg_(0.45)Ti_(3.55)O_(8)-Na_(2)Ni_(2)Ti_(6)O_(16)solid solutions for improving photocatalytic CO_(2)reduction
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作者 WANG Jingzhou YAO Chenzhong +2 位作者 ZHANG Xisheng MA Ziwei LI Linfeng 《燃料化学学报(中英文)》 北大核心 2026年第1期15-25,共11页
In this study,a straightforward one-step hydrothermal method was successfully utilized to synthesize the solid solution Na_(0.9)Mg_(0.45)Ti_(3.55)O_(8)-Na_(2)Ni_(2)Ti_(6)O_(16)(NNMTO-x),where x denotes the molar perce... In this study,a straightforward one-step hydrothermal method was successfully utilized to synthesize the solid solution Na_(0.9)Mg_(0.45)Ti_(3.55)O_(8)-Na_(2)Ni_(2)Ti_(6)O_(16)(NNMTO-x),where x denotes the molar percentage of Na_(2)Ni_(2)Ti_(6)O_(16)(NNTO)within Na_(0.9)Mg_(0.45)Ti_(3.55)O_(8)(NMTO),with x values of 10,20,30,40,and 50.Both XPS(X-ray Photoelectron Spectroscopy)and EDX(Energy Dispersive X-ray Spectroscopy)analyses unequivocally validated the formation of the NNMTO-x solid solutions.It was observed that when x is below 40,the NNMTO-x solid solution retains the structural characteristics of the original NMTO.However,beyond this threshold,significant alterations in crystal morphology were noted,accompanied by a noticeable decline in photocatalytic activity.Notably,the absorption edge of NNMTO-x(x<40)exhibited a shift towards the visible-light spectrum,thereby substantially broadening the absorption range.The findings highlight that NNMTO-30 possesses the most pronounced photocatalytic activity for the reduction of CO_(2).Specifically,after a 6 h irradiation period,the production rates of CO and CH_(4)were recorded at 42.38 and 1.47μmol/g,respectively.This investigation provides pivotal insights that are instrumental in the advancement of highly efficient and stable photocatalysts tailored for CO_(2)reduction processes. 展开更多
关键词 photocatalytic conversion hydrothermal method optical response range solid solution charge separation
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New criteria on the existence and global exponential stability of periodic solutions for quaternion-valued cellular neural networks
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作者 LI Ai-ling ZHOU Zheng ZHANG Zheng-qiu 《Applied Mathematics(A Journal of Chinese Universities)》 2025年第3期523-542,共20页
In this paper,a class of quaternion-valued cellular neural networks(QVCNNS)with time-varying delays are considered.Combining graph theory with the continuation theorem of Mawhin’s coincidence degree theory as well as... In this paper,a class of quaternion-valued cellular neural networks(QVCNNS)with time-varying delays are considered.Combining graph theory with the continuation theorem of Mawhin’s coincidence degree theory as well as Lyapunov functional method,we establish new criteria on the existence and exponential stability of periodic solutions for QVCNNS by removing the assumptions for the boundedness on the activation functions and the assumptions that the values of the activation functions are zero at origin.Hence,our results are less conservative and new. 展开更多
关键词 the existence of periodic solutions exponential stability quaternion-valued cellular neural networks combining graph theory with Mawhin’s continuation theorem of coincidence degree theory Lyapunov function method inequality techniques
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Optimal combination of substrate supply amount coupled with nutrient solution management program for cucumber planting
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作者 Zhen Kang Zhaoxi Jiang +5 位作者 Zhaolong Liu Peng Wang Caihong Zhang Maozhou Yuan Mengqi Bai Xiaohui Hu 《Horticultural Plant Journal》 2026年第1期136-148,共13页
Substrate and nutrient supply are essential for vegetable cultivation in greenhouse.The strategies for plant nutrient supply vary depending on the cultivation methods or substrate dosages employed.With the development... Substrate and nutrient supply are essential for vegetable cultivation in greenhouse.The strategies for plant nutrient supply vary depending on the cultivation methods or substrate dosages employed.With the development of mechanization,wide-row spacing substrate cultivation became an optimize mode of the greenhouse cucumber cultivation,aligning with the trend of intelligent agriculture.To determine the optimal nutrient solution supply amount(NS)and supply frequency(SF)for promoting the integrated growth of cucumber under wide-row spacing substrate cultivation,we explored the effects of substrate supply amount(SS),NS,and SF on cucumber yield,quality,and element utilization efficiency.A five-level quadratic orthogonal rotation combination design with three experimental factors(NS,SF,and SS)was implemented for 23 coupling treatments over three growing seasons,including spring(2022S and 2023S)and autumn(2022A).The technique for order preference by similarity to ideal solution(TOPSIS)combining weights based on game theory was applied to construct cucumber comprehensive growth evaluation model.Single and two experimental factors analyses revealed significant effects of single factors and the coupling of NS-SS,NS-SF and SS-SF on the integrated growth of cucumber for all three growing seasons.For the NS-SF-SS combination,the optimal parameters for comprehensive cucumber growth were determined as follows:levels of^(-1).68 for NS,-0.7 for SF,and^(-1).682 for SS in 2022A;-0.43 for NS,-0.06 for SF,and 0.34 for SS in 2022S;0.3 for NS,-0.02 for SF,and 0.04 for SS in 2023S.Furthermore,for SS ranges of 2.00-3.01,3.01-4.50,4.50-5.99,5.99-7.00(L·plant^(-1)),the corresponding NS and SF intervals maximizing cucumber integrated growth in spring were:0.28-0.30(L·plant^(-1))and 6(times·d^(-1)),0.26-0.30(L·plant^(-1))and 6(times·d^(-1)),0.25-0.30(L·plant^(-1))and 6(times·d^(-1)),0.23-0.30(L·plant^(-1))and 6(times·d^(-1)),respectively.With the same SS,the corresponding NS and SF intervals that maximized cucumber integrated growth in autumn were:0.10(L·plant^(-1))and 8(times·d^(-1)),0.18(L·plant^(-1))and 7(times·d^(-1)),0.30(L·plant^(-1))and 6(times·d^(-1)),0.49(L·plant^(-1))and 5(times·d^(-1)),respectively.The results provide a theoretical basis for solution management,and further in-depth research on cucumber cultivation. 展开更多
关键词 Cucumis sativus L. Comprehensive growth Irrigation frequency Nutrient solution Substrate supply amount Wide row spacing
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Effect and mechanism of Ti−O solid solution layer on interfacial bonding strength of cold roll bonded titanium/stainless steel laminated composite plate
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作者 Zhi-yan YANG Xue-feng LIU +1 位作者 Hong-ting CHEN Xin MA 《Transactions of Nonferrous Metals Society of China》 2026年第1期171-182,共12页
Titanium plates with a Ti−O solid solution surface-hardened layer were cold roll-bonded with 304 stainless steel plates with high work hardening rates.The evolution and mechanisms affecting the interfacial bonding str... Titanium plates with a Ti−O solid solution surface-hardened layer were cold roll-bonded with 304 stainless steel plates with high work hardening rates.The evolution and mechanisms affecting the interfacial bonding strength in titanium/stainless steel laminated composites were investigated.Results indicate that the hardened layer reduces the interfacial bonding strength from over 261 MPa to less than 204 MPa.During the cold roll-bonding process,the hardened layer fractures,leading to the formation of multi-scale cracks that are difficult for the stainless steel to fill.This not only hinders the development of an interlocking interface but also leads to the presence of numerous microcracks and hardened blocks along the nearly straight interface,consequently weakening the interfacial bonding strength.In metals with high work hardening rates,the conventional approach of enhancing interface interlocking and improving interfacial bonding strength by using a surface-hardened layer becomes less effective. 展开更多
关键词 titanium/stainless steel laminated composite plate Ti−O solid solution hardened layer interlocking interface formation mechanism interfacial bonding strength
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Synergistic extraction of zinc from ammoniacal solutions using β-diketone mixed with CYANEX923 or LIX84I 被引量:4
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作者 胡久刚 陈启元 +1 位作者 胡慧萍 尹周澜 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第5期1217-1223,共7页
The extraction behaviors of zinc from ammoniacal solutions were investigated using β-diketone (HA) and their mixtures with CYANEX923 or LIX84I. The effects of pH, total ammonia concentration, extractant concentrati... The extraction behaviors of zinc from ammoniacal solutions were investigated using β-diketone (HA) and their mixtures with CYANEX923 or LIX84I. The effects of pH, total ammonia concentration, extractant concentration, anion species and temperature on zinc extraction were examined. The synergistic mechanism was discussed with regard to the structure of extractant and the extracted zinc complexes. It is found that the increase of total ammonia concentration and pH inhibits zinc extraction for all extraction systems due to the formation of zinc ammine complexes in aqueous phase. This effect of HA with CYANEX923 is evidently smaller than that of HA with LIX84I or HA alone system. Effect of anion species on the zinc extraction by HA with CYANEX923 can be neglected, but this effect of HA alone and the mixture of HA with LIX84I decreases in the order of (NH4)2SO4 〉 NH4NO3 〉 NH4Cl. 展开更多
关键词 synergistic extraction ZINC ammoniacal solution Β-DIKETone CYANEX923 LIX84I
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点式锻压激光沉积Inconel718合金热处理工艺优化
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作者 张瑞林 《电镀与精饰》 北大核心 2026年第1期93-100,共8页
针对传统合金制备工艺成本高、周期长等问题,以点式锻压激光沉积技术制备的Inconel718合金为对象,进行了热处理工艺优化探索。通过系统地研究热处理温度、时效时间等参数对合金组织和性能的影响,提出了一种最优热处理工艺方法。实验显示... 针对传统合金制备工艺成本高、周期长等问题,以点式锻压激光沉积技术制备的Inconel718合金为对象,进行了热处理工艺优化探索。通过系统地研究热处理温度、时效时间等参数对合金组织和性能的影响,提出了一种最优热处理工艺方法。实验显示,固溶温度为1020℃、时效时间为4 h时,Inconel718合金经过热处理后的力学性能最优。此时,合金屈服强度1171.2 MPa,拉伸强度1399.3 MPa,延伸率11.7%,显微硬度550.3 HV。研究结果表明,固溶温度增加与时效时间减少对Inconel718合金性能具有明显的影响,且固溶温度变化产生的影响明显高于时效时间。该研究不仅提高了Inconel718合金的力学性能,还缩短了热处理时间,降低了能耗,具有重要的理论意义和应用价值。 展开更多
关键词 点式锻压 激光沉积 热处理 固溶温度 时效时间
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Iterative Solution for Systems of Binary Non-mixed Monotone Operator Equations 被引量:2
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作者 左秀会 《Chinese Quarterly Journal of Mathematics》 CSCD 2001年第3期80-83,共4页
With using the cone and partial ordering t heory and mixed monotone operator theory, the existence and uniqueness for solut ion of systems of non-monotone binary nonliear operator equations are discussed. And the it... With using the cone and partial ordering t heory and mixed monotone operator theory, the existence and uniqueness for solut ion of systems of non-monotone binary nonliear operator equations are discussed. And the iterative sequences which converge to solution of systems of operator e quations and the error estimates are also given. Some corresponding results for the mixed monotone operations and the unary operator equations are improved and generalized. 展开更多
关键词 binary operator mixed monotone operators syste ms of equations solutionS cone and partial ordering
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Exponential stability and existence of periodic solutions for a class of recurrent neural networks with delays 被引量:1
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作者 戴志娟 《Journal of Southeast University(English Edition)》 EI CAS 2006年第2期286-293,共8页
Both the global exponential stability and the existence of periodic solutions for a class of recurrent neural networks with continuously distributed delays (RNNs) are studied. By employing the inequality α∏k=1^m ... Both the global exponential stability and the existence of periodic solutions for a class of recurrent neural networks with continuously distributed delays (RNNs) are studied. By employing the inequality α∏k=1^m bk^qk≤1/r ∑qkbk^r+1/rα^r(α≥0,bk≥0,qk〉0,with ∑k=1^m qk=r-1,r≥1, constructing suitable Lyapunov r k=l k=l functions and applying the homeomorphism theory, a family of simple and new sufficient conditions are given ensuring the global exponential stability and the existence of periodic solutions of RNNs. The results extend and improve the results of earlier publications. 展开更多
关键词 recurrent neural network global exponential stability periodic solution delay HOMEOMORPHISM Lyapunov function
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Inconel690-NiCr涂层管在高温苛性碱溶液中的腐蚀行为研究
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作者 王瑞 李翔龙 +4 位作者 岳耀民 于洋洋 苗启凯 霍同龙 苏凯峰 《表面技术》 北大核心 2026年第2期24-37,共14页
目的蒸汽发生器传热管是压水堆(PWR)核电站一、二回路的热交换枢纽,其材料耐腐蚀性能影响着压水堆核电站的使用寿命,鉴于此,研究了690-NiCr涂层管在正常工况和非正常工况下的耐腐蚀性能,揭示了温度和pH对690-NiCr涂层管氧化膜形成过程... 目的蒸汽发生器传热管是压水堆(PWR)核电站一、二回路的热交换枢纽,其材料耐腐蚀性能影响着压水堆核电站的使用寿命,鉴于此,研究了690-NiCr涂层管在正常工况和非正常工况下的耐腐蚀性能,揭示了温度和pH对690-NiCr涂层管氧化膜形成过程的影响。方法采用水循环系统的高压釜设备模拟压水堆(PWR)真实工况,利用大气等离子喷涂(Air Plasma Spraying,APS)技术制备Ni-Cr涂层,设计了二回路水环境(285℃)、偏离工况水环境(320℃)、次临界水环境(360℃)以及不同pH值(pH=7.0、pH=9.8、pH=10.6)实验方案;通过SEM、EDS和XRD分析了氧化膜形貌及成分、元素含量和腐蚀机理。结果在二回路水环境下,涂层管在三种pH水环境下的表面氧化物形状相似,表面覆盖颗粒状氧化物并伴随针状氧化物;在320℃偏离工况水环境下,涂层管在三种pH下均形成了形状不规则的颗粒状外层氧化膜和致密的内层氧化膜,外层氧化膜富含Cr,Ni次之,内层氧化膜则相反;在次临界水环境下,涂层管所形成的内外层氧化膜成分差别较小,均富含Cr、Ni元素,不同的是,pH=10.6时的氧含量较低。结论涂层管在二回路水环境中形成了三层氧化膜,外层氧化膜主要为Cr(OH)_(3)、Ni(OH)_(2)和NiO;中间层氧化膜主要由单质Ni、少量NiO和Fe的氧化物构成;内层氧化膜由Cr_(2)O_(3)构成;随着温度的上升,涂层管表面氧化膜厚度增加,外层氧化物颗粒长大,内层氧化膜遭到破坏,保护性变差,基体的腐蚀速率增加。 展开更多
关键词 蒸汽发生器 690-NiCr涂层管 高温苛性溶液 氧化膜成分 腐蚀机理
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