A new type additive was added to the non-self-fluxing copper powdered alloy, and the powder showed satisfactory performance of spraying and fusing, self-protecting, and self-fluxing in the oxygen-acetylene flame spray...A new type additive was added to the non-self-fluxing copper powdered alloy, and the powder showed satisfactory performance of spraying and fusing, self-protecting, and self-fluxing in the oxygen-acetylene flame spraying and fusing process. The additive was melted and could absorb copper oxide when spraying, then it created a layer of film to cover the copper liquid, which protected the copper liquid from oxidizing efficiently and promoted it wetting on iron surface. Thus it lead to real diffusion between Cu and Fe, which resolved the diffwulty of combining Cu with Fe and reduced the limitation of the powder, and it promoted the usage value of general powder. Through analysis of microstructures, it was found that the fastness and compactness of the combining interface was excellent as well as the diffusing of transition area, and the hardness was suitable, which meant that the performance could meet the needs of high quality valves completely.展开更多
In this article we are interested in the numerical computation of spectra of non-self adjoint quadratic operators,in two and three spatial dimensions.Indeed,in the multidimensional case very few results are known on t...In this article we are interested in the numerical computation of spectra of non-self adjoint quadratic operators,in two and three spatial dimensions.Indeed,in the multidimensional case very few results are known on the location of the eigenvalues.This leads to solve nonlinear eigenvalue problems.In introduction we begin with a review of theoretical results and numerical results obtained for the one dimensional case.Then we present the numerical methods developed to compute the spectra(finite difference discretization)for the two and three dimensional cases.The numerical results obtained are presented and analyzed.One difficulty here is that we have to compute eigenvalues of strongly non-self-adjoint operators which are unstable.This work is in continuity of a previous work in one spatial dimension[3].展开更多
文摘A new type additive was added to the non-self-fluxing copper powdered alloy, and the powder showed satisfactory performance of spraying and fusing, self-protecting, and self-fluxing in the oxygen-acetylene flame spraying and fusing process. The additive was melted and could absorb copper oxide when spraying, then it created a layer of film to cover the copper liquid, which protected the copper liquid from oxidizing efficiently and promoted it wetting on iron surface. Thus it lead to real diffusion between Cu and Fe, which resolved the diffwulty of combining Cu with Fe and reduced the limitation of the powder, and it promoted the usage value of general powder. Through analysis of microstructures, it was found that the fastness and compactness of the combining interface was excellent as well as the diffusing of transition area, and the hardness was suitable, which meant that the performance could meet the needs of high quality valves completely.
基金supported by the Fédération de Mathématiques des Pays de la Loire,CNRS FR 2962。
文摘In this article we are interested in the numerical computation of spectra of non-self adjoint quadratic operators,in two and three spatial dimensions.Indeed,in the multidimensional case very few results are known on the location of the eigenvalues.This leads to solve nonlinear eigenvalue problems.In introduction we begin with a review of theoretical results and numerical results obtained for the one dimensional case.Then we present the numerical methods developed to compute the spectra(finite difference discretization)for the two and three dimensional cases.The numerical results obtained are presented and analyzed.One difficulty here is that we have to compute eigenvalues of strongly non-self-adjoint operators which are unstable.This work is in continuity of a previous work in one spatial dimension[3].
