RT Journal T1 OPTIMAL BIRKHOFF INTERPOLATION AND BIRKHOFF NUMBERS IN SOME FUNCTION SPACES* A1 Guiqiao XU, Yongping Liu, Dandan GUO PB Acta mathematica scientia,Series B FD 2023-02-25 YR 2023 JF Acta mathematica scientia, Series B JO Acta mathematica scientia,Series B VO 43 IS 1 SP 125 DO 10.1007/s10473-023-0108-5 K1 optimal Birkhoff interpolation;Birkhoff number;Sobolev space;worst case setting LK {http://121.43.60.238/sxwlxbB/EN/article/article_16910.shtml}