Three characteristic points in the deformation history of a fractured tensile specimen are selected tocalculate two values of n( n1 and n2 ) to represent the hardening ability of material during the homogeneous plas-t...Three characteristic points in the deformation history of a fractured tensile specimen are selected tocalculate two values of n( n1 and n2 ) to represent the hardening ability of material during the homogeneous plas-tic deformation and the following large plastic deformation. Experimental results obtained with mild streel andred copper show that n determined using the three-point method proposed is better to describe the hardening a-bility of material. It is therefore concluded that three-point method can be used to describe the hardening prop-erty of material during both homogeneous deformation and large plastic deformation.展开更多
We study the existence of positive solutions of the three-point boundary value problem u＂＋g（t）f（u）=0,t∈（0,1）,u′（0）=0,u（1）=αu（η）, where η∈（0, 1）, and α∈R with 0 〈α〈 1. The existence of posit...We study the existence of positive solutions of the three-point boundary value problem u＂＋g（t）f（u）=0,t∈（0,1）,u′（0）=0,u（1）=αu（η）, where η∈（0, 1）, and α∈R with 0 〈α〈 1. The existence of positive solutions is studied by means of fixed point index theory under some conditions concerning the first eigenvalue with respect to the relevant linear operator. The results, here essentially extend and improve the main result in [1].展开更多
文摘Three characteristic points in the deformation history of a fractured tensile specimen are selected tocalculate two values of n( n1 and n2 ) to represent the hardening ability of material during the homogeneous plas-tic deformation and the following large plastic deformation. Experimental results obtained with mild streel andred copper show that n determined using the three-point method proposed is better to describe the hardening a-bility of material. It is therefore concluded that three-point method can be used to describe the hardening prop-erty of material during both homogeneous deformation and large plastic deformation.
基金the Natural Science Foundation of Gansu Province(3ZS051-A25-016)NWNU-KJCXGCthe Spring-sun program(Z2004-1-62033).
文摘We study the existence of positive solutions of the three-point boundary value problem u＂＋g（t）f（u）=0,t∈（0,1）,u′（0）=0,u（1）=αu（η）, where η∈（0, 1）, and α∈R with 0 〈α〈 1. The existence of positive solutions is studied by means of fixed point index theory under some conditions concerning the first eigenvalue with respect to the relevant linear operator. The results, here essentially extend and improve the main result in [1].
