We investigate Besov spaces and their connection with trigonometric polynomial approximation in L_p[－π,π], algebraic polynomial approximation in L_p[-1,1], algebraic polynomial approximation in L_p(S), and entir...We investigate Besov spaces and their connection with trigonometric polynomial approximation in L_p[－π,π], algebraic polynomial approximation in L_p[-1,1], algebraic polynomial approximation in L_p(S), and entire function of exponential type approximation in Lp(R), and characterize K-functionals for certain pairs of function spaces including (Lp [-π,π], B_s~α (Lp[-π，π])), (L_p(R),B_s~α (Lp(R))), (Lp[-1,1],B_s~α (Lp[-1,1])), and (Lp(S),B_s~α (Lp(S))), where 0<s<, 0<p<1, S is a simple polytope and 0<α<r.展开更多
文摘本文研究了铸态、固溶态和时效过程的Mg-1.67at.%Zn-2.3at.%Dy与Mg-1.51at.%Zn-2.77at.%Er合金的微观结构变化及其力学性能的影响。微观分析结果表明,Mg-1.67at.%Zn-2.3at.%Dy与Mg-1.51at.%Zn-2.77at.%Er合金,在493 K温度下时效20 h硬度均达到峰值,峰值硬度分别为106.4 HV和98.7 HV。拉伸试验结果表明,固溶处理后,合金Mg-1.67at.%Zn-2.3at.%Dy与Mg-1.51at.%Zn-2.77at.%Er的抗拉强度均有明显的提高。合金Mg-1.67at.%Zn-2.3at.%Dy固溶后包含三个相,分别是α-Mg相,Mg8Zn Dy共晶相,Mg12Zn Dy LPSO相(包括14H型和18R型)。合金Mg-1.51at.%Zn-2.77at.%Er固溶后包含三个相,分别是α-Mg相,Mg3Zn3Er2共晶相,Mg12Zn Er LPSO相(包括14H型和18R型)。
基金This project is supported by the National Natural Science Foundation of China.
文摘We investigate Besov spaces and their connection with trigonometric polynomial approximation in L_p[－π,π], algebraic polynomial approximation in L_p[-1,1], algebraic polynomial approximation in L_p(S), and entire function of exponential type approximation in Lp(R), and characterize K-functionals for certain pairs of function spaces including (Lp [-π,π], B_s~α (Lp[-π，π])), (L_p(R),B_s~α (Lp(R))), (Lp[-1,1],B_s~α (Lp[-1,1])), and (Lp(S),B_s~α (Lp(S))), where 0<s<, 0<p<1, S is a simple polytope and 0<α<r.
