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Rare Metals 2024年第5期43卷 2275-2281页

作者： Guo-Chao Li Xu Cheng hua-ming wang National Engineering Laboratory of Additive Manufacturing for Large Metallic Components and Engineering Research Center of Ministry of Education on Laser Direct Manufacturing for Large Metallic Components School of Materials Science and EngineeringBeihang UniversityBeijing 100191China

The solid solution and aging treatment for conventional manufacturing processes might not be suitable for laser additive manufactured titanium alloys due to the different lamellar *** this study,the influence of aging temperatures(600,700 and 800°C)on microstructure and mechanical properties of titanium alloy Ti-6Al-2V-1.5Mo-0.5Zr-0.3Si was *** results indicate that after solid solution treatment at 970°C followed by water quenching,the alloy mainly consists of coarsening lamellar a phase in martensite α' *** at 600°C will not change the size of primary lamellar α phase but lead to huge amount of secondary a phases(α_(s))generating with very fine *** increasing the aging temperature,the number of α_(s) decreases but with coarsened *** aged at 800°C,the width of the asphase reaches 350 nm,almost 7 times wider than that aged at 600°*** changing size of α_(s) obviously influences the property of the *** fine α_(s) leads to high strength and microhardness but low plasticity,and specimen aged at 700°C with suitable assize has the best comprehensive properties.

关键词： α+βtitanium alloy Laser additive manufacturing Solid solution and aging treatment Microstructure Room temperature tensile property

Times of a Branching Process with Immigration in Varying Environments Attaining a Fixed Level

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Acta Mathematica Sinica,English Series 2024年

作者： hua-ming wang School of Mathematics and Statistics Anhui Normal University

Consider a branching process{Z_n}n≥0with immigration in varying *** a∈{0,1,2,...},let C（a）={n≥0:Z_n=a}be the collection of times at which the population size of the process attains level *** give a criterion to determine whether the set C（a） is finite or *** the critical Galton-Watson process,based on a moment method,we show that|C（a）∩[1,n]|/log n→Sin distribution,where S is an exponentially distributed random variable with P （S>t）=e-t,t>0.

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变环境下两物种分枝过程灭绝时的极限定理

中国科学：数学 2024年第6期54卷 839-862页

作者：王华明安徽师范大学数学与统计学院芜湖241003

考虑变环境下两物种分枝过程.假定系统中个体的后代分布为线性分式分布且后代分布的均值矩阵存在极限,设ν为过程的灭绝时,且对k1记M_(k)为第k-1代个体的后代均值矩阵.在一定条件下,本文证明当n→∞时,P(ν=n)和P(ν>n)渐近等价于后代... 详细信息

考虑变环境下两物种分枝过程.假定系统中个体的后代分布为线性分式分布且后代分布的均值矩阵存在极限,设ν为过程的灭绝时,且对k1记M_(k)为第k-1代个体的后代均值矩阵.在一定条件下,本文证明当n→∞时,P(ν=n)和P(ν>n)渐近等价于后代均值矩阵谱半径乘积的一些函数,推广了wang和Yao(2022)的结论.wang和Yao(2022)需要一个特定的假设,即存在ε>0使得对于任意k1,有det(M_(k))<-ε.在该假设下,系统中的个体更倾向于产生另一个物种的子女,故而将一大类矩阵排除在均值矩阵之外.本文去除了这一额外的假设,研究了灭绝时的分布极限理论.此外,为证明灭绝时的极限定理,本文用谱半径乘积给出了非齐次2阶矩阵乘积内部元素极限行为的等价刻画,并得到渐近周期连分数一些精细的极限定理.这些结论在非齐次矩阵乘积的遍历理论及连分数的极限理论中也自有其意义.

关键词：变环境下分枝过程灭绝时非齐次矩阵乘积谱半径连分数

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Vortex identification based on the Liutex method and its effect on fish passage upstream

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Journal of Hydrodynamics 2024年第1期36卷 130-141页

作者： Chun-ying Shen Rui-guo Yang Xiao-tao Shi ming-ming wang Shi-hua He Faculty of Electrical Power Engineering Kunming University of Science and TechnologyKunming650500China Hubei International Science and Technology Cooperation Base of Fish Passage China Three Gorges UniversityYichang443002China Shanghai Investigation Design and Research Institute Co.LtShanghai200434China

Fishway research is important for mitigating the fragmentation of river habitats caused by hydraulic *** vertical slit fishway is a broadly used fishway type because of its high efficiency and adaptability to water ***,the resulting vortex current disrupts the fish passage hence directly affecting fish *** study aims to accurately capture the vortex structure in the fishway and analyze the effect of vortex elements(vortex structure,vortex intensity,etc.)on *** conducted an analysis of the 3-D current flow field in the fishway through the utilization of an experimental model and the large eddy simulation(LES)***,we captured the vortex information in the fishway at different flow rates using the Liutex vortex identification method and investigated the effect of the vortex on fish *** results revealed that the structures inside the fishway pool occupy most of the room,however,the areas with higher vortex strength were primarily located in the vortex near the vertical seam and the mainstream,the vortex strength inside the fishway gradually increases with increasing flow,suppressing fish *** experienced significantly increased resistance when encountering strong *** suggests that the vortex may act as a physical barrier to fish *** findings highlight the potential negative effects of vortex on fish movement and reiterate the importance of understanding vortex dynamics for aquatic environmental *** an effective tool for identifying vortices in fluid flow,the Liutex method demonstrates features of vortex within the fishway,thereby providing important insights into the interaction between fluid dynamics and aquatic organisms.

关键词： Vertical slit fishway vortex identification method Liutex large eddy simulation(LES) fish experiment computational fluid dynamics

On Total Progeny of Multitype Galton-Watson Process and the First Passage Time of Random Walk on Lattice

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Acta Mathematica Sinica,English Series 2014年第12期30卷 2161-2172页

作者： hua ming wang Department of Mathematics Anhui Normal University

In this paper,we form a method to calculate the probability generating function of the total progeny of multitype branching *** examples,we calculate probability generating function of the total progeny of the multitype branching processes within random walk which could stay at its position and（2-1） random ***,we could give the probability generating functions and the distributions of the first passage time of corresponding random ***,for recurrent random walk which could stay at its position with probability 0 〈 r 〈 1,we show that the tail probability of the first passage time decays as 2/√π（1-r）1/√n= when n →∞.

关键词： Multitype branching process total progeny random walk

A Note on Multitype Branching Process with Bounded Immigration in Random Environment

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Acta Mathematica Sinica,English Series 2013年第6期29卷 1095-1110页

作者： hua ming wang Department of Mathematics Anhui Normal University

In this paper, we study the total number of progeny, W, before regenerating of multitype branching process with immigration in random environment. We show that the tail probability of ｜W｜ is of order t-κ as t→∞, with κ some constant. As an application, we prove a stable law for （L-1） random walk in random environment, generalizing the stable law for the nearest random walk in random environment （see ＂Kesten, Kozlov, Spitzer： A limit law for random walk in a random environment. Compositio Math., 30, 145-168 （1975）＂）.

关键词： Branching process random walk random environment

Effect of Al content in molten steel on interaction between MgO-C refractory and SPHC steel

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Journal of Iron and Steel Research(International) 2024年第4期31卷 838-848页

作者： Fu-bin Gao Fu-ming wang Xiang Zhang Tian-yu Du Xin-hua wangg School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China Handan Iron and Steel Company Hegang GroupHandan 056015HebeiChina The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina

The effect of Al content in molten steel on the interaction between SPHC steel(0.005-0.068 wt.%Al,and 19×10^(-4)-58×10^(-4)wt.%O)and MgO-C refractory(11.63 wt.%C)was ***-metallic inclusions in the steel were examined at various periods(0,5,15,30,45,and 60 min)as well as the MgO-C interface after 60 min of corrosion at 1600℃.The results show that when MgO-C refractory comes into contact with SPHC steel,the refractory interface consists of three layers arranged from the innermost to the outermost,including the original refractory layer,the dense MgO layer,and the iron infiltration *** carbon in the MgO-C refractories and the Al content in the molten steel undergo a reaction with the MgO in the refractories,resulting in an increase in Mg concentration in the *** Al content in the molten steel from 0.005 to 0.068 wt.%causes a spinel layer to appear at the interface,and the disappearance time of Al_(2)O_(3) inclusions in the steel decreases from 60 to 30 min,while the average MgO content in inclusions ***,controlling the Al content in the molten steel and the smelting duration can help regulate the formation of spinel inclusionsinthe steel.

关键词： MgO-C refractory SPHC steel Inclusion-Spinel Al-killed steel Interfacial reaction

Plasmon-enhanced ultra-high photoresponse of single-wall carbon nanotube/copper/silicon near-infrared photodetectors

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Nano Research 2024年第7期17卷 5930-5936页

作者： Yi-ming Zhao Xian-Gang Hu Chao Chen Zuo-hua wang An-Ping Wu Hong-wang Zhang Peng-Xiang Hou Chang Liu Hui-ming Cheng Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China National Engineering Research Center for Equipment and Technology of Cold Strip Rolling College of Mechanical EngineeringYanshan UniversityQinhuangdao 066004China Faculty of Materials Science and Engineering/Institute of Technology for Carbon Neutrality Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China

Single wall carbon nanotube(SWCNT)/Si heterojunction photodetectors have the advantages of high photoresponse ability and simple structure,however,their detection wavelength range are usually lower than 1100 nm,which limits their application in the infrared *** report a SWCNT/Cu/Si photodetector with both a high photoresponse and a detection range up to the infrared band by depositing a Cu nanoparticles(NPs)layer between a SWCNT film and a n-Si *** was found that the Cu NPs produce strong surface plasmon resonance(SPR)under laser irradiation,which breaks through the limitation of Si band gap and greatly improves the photoresponse of the SWCNT/Cu/Si photodetector in the near infrared *** responsivity(R)of the photodetector in the wavelength range of 1850–1200 nm reached 2.2–14.15 mA/W,which is the highest value in the reported plasmon enhanced n-Si based photodetectors,and about 20,000 times higher than that of a SWCNT/Si *** R value for 1550 nm wavelength used in optical communications reached~8.2 mA/W,which is 64%higher than the previously reported values of commonly used *** attribute the significant increase to the strong SPR and low Schottky barrier of Cu with n-Si,which facilitates the generation and transfer of the carriers.

关键词： single wall carbon nanotube photodetector silicon surface plasmon resonance copper

Triphenylphosphine as Reducing Agent for Copper(II)-catalyzed AGET ATRP

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Chinese Journal of Polymer Science 2015年第9期33卷 1260-1270页

作者：柏良久 Wen-xiang wang ming-hua wang Jin-ming Sun 陈厚 School of Chemistry and Materials Science Ludong University

Triphenylphosphine （TPP） was used as reducing agent to continuously generate the Cu（I） activator in copper（II）- catalyzed activators generated by electron transfer atom transfer radical polymerization （AGET ATRP）. For example, the polymers prepared with a molar ratio of [MMA]0/[EBiB]0/[CuC12]o/[PMDETA]0/[TPP]o = 500/1/0.1/0.5/0.5 had controlled molecular weights and low molecular weight distribution （Mw/Mn） values （-1.2）. TPP as a commercial reducing agent provides a convenient copper-catalyzed AGET ATRP procedure for the preparation of well-defined polymers.

关键词： ATRP AGET ATRP Reducing agent Triphenylphosphine (TPP).

Sequential enantioselective Ugi-4CR/post-Ugi transformation strategy:a precise construction of structurally diverse azaspiro polycyclic scaffolds

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Science China Chemistry 2024年第2期67卷 576-586页

作者： Xiao-Bao Wu Jun-Xiu Shi Yi-ming Ou hua-Jie Jiang Yi-Jun Fang Qi-ming wang Quan Gao Jie Yu Department of Applied Chemistry Anhui Province Engineering Laboratory for Green Pesticide Development and ApplicationAnhui Province Key Laboratory of Crop Integrated Pest ManagementAnhui Agricultural UniversityHefei230036China

A privileged strategy has been developed for the precise construction of enantioenriched azaspiro polycyclic *** diverse azaspiro polycycles bearing multiple contiguous stereocenters are obtained with excellent results(up to 99:1 e.r.,>95:5 d.r.) via sequential enantioselective four-component Ugi reactions/post-Ugi transformations with substrates containing prerequisite functional groups in the presence of anionic stereogenic-at-cobalt(Ⅲ) complexes.

关键词： asymmetric catalysis post-Ugi transformation anionic stereogenic-at-cobalt(Ⅲ)complex azaspiro polycyclic scaffold one-pot synthesis