MoSi2 laser cladding—a comparison between two experimental procedures: Mo–Si online combination and direct use of MoSi2

There are very strong interests in developing low density advanced material systems for service at temperatures up to 1300°C. These materials should mainly have moderate fracture toughness at low and intermediate temperatures and should exhibit oxidation resistant behaviour. The intermetallic compound, MoSi₂ has been considered to be an attractive candidate due to its melting point (2030°C) and excellent oxidation resistance at high temperatures. In this paper, we compare the results obtained with two different techniques for laser cladding, one using an online combination between Mo and Si powders, the second using direct injection of the MoSi₂ powder.     

CENTRAL LIMIT THEOREMS FOR A BRANCHING RANDOM WALK WITH A RANDOM ENVIRONMENT IN TIME

We consider a branching random walk with a random environment in time, in which the offspring distribution of a particle of generation n and the distribution of the displacements of its children depend on an environment indexed by the time n. The environment is supposed to be independent and identically distributed. For AR, let Zn(A) be the number of particles of generation n located in A. We show central limit theorems for the counting measure Zn(·) with appropriate normalization.     

Weighted moments for a supercritical branching process in a varying or random environment

Let W be the limit of the normalized population size of a supercritical branching process in a varying or random environment. By an elementary method, we find sufficient conditions under which W has finite weighted moments of the form EWpl(W), where p > 1, l 0 is a concave or slowly varying function.     

Velocity Distribution of the Powder Particles in Laser Cladding

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Velocity Distribution of the Powder Particles in Laser Cladding

The velocity distribution of powder particles in the laser cladding has an important influence on the motion of liquid in the laser molten pool. In this paper, considering the carrier gas leaving the nozzle to be a steady jet, the velocity distribution of the powder particles is obtained, which can be used as input data in the modelling of the laser cladding.     

单位圆内代数体函数的T半径

应用Ahlfors覆盖曲面的方法,在单位圆内构造了代数体函数的一个新的奇异半径(称为T半径),并应用无穷级的型函数推广了亚纯函数奇异方向的相关结论.