To conduct this study, the literatures, questionnaires, interviews and other methods were used, the analysis of the present situation and health status of the students’ physical education in universities “special gr...To conduct this study, the literatures, questionnaires, interviews and other methods were used, the analysis of the present situation and health status of the students’ physical education in universities “special group”, and the nature of the course and teaching modes of thinking were also done in order to provide references to improve sports education in colleges and universities.展开更多
In this paper,we study the theory of complements,introduced by Shokurov,for Calabi-Yau type varieties with the coefficient set[0,1].We show that there exists afinite set of positive integers N,such that if a threefold p...In this paper,we study the theory of complements,introduced by Shokurov,for Calabi-Yau type varieties with the coefficient set[0,1].We show that there exists afinite set of positive integers N,such that if a threefold pair(X/Z∋z,B)has an R-complement which is klt over a neighborhood of z,then it has an n-complement for some n∈N.We also show the boundedness of complements for R-complementary surface pairs.展开更多
Let(X, ?) be a log pair over S, such that-(KX+ ?) is nef over S. It is conjectured that the intersection of the non-klt(non Kawamata log terminal) locus of(X, ?) with any fiber Xs has at most two connected components....Let(X, ?) be a log pair over S, such that-(KX+ ?) is nef over S. It is conjectured that the intersection of the non-klt(non Kawamata log terminal) locus of(X, ?) with any fiber Xs has at most two connected components. We prove this conjecture in dimension no greater than 4 and in arbitrary dimension assuming the termination of klt flips.展开更多
文摘To conduct this study, the literatures, questionnaires, interviews and other methods were used, the analysis of the present situation and health status of the students’ physical education in universities “special group”, and the nature of the course and teaching modes of thinking were also done in order to provide references to improve sports education in colleges and universities.
基金supported by the China Post-doctoral Science Foundation(Grant Nos.BX2021269 and 2021M702925)supported by National Key Research and Development Program of China(Grant No.2020YFA0713200)+1 种基金supported by NSF Research Grants(Nos.DMS-1801851 and DMS-1952522)by a grant from the Simons Foundation(Award Number:256202).
文摘In this paper,we study the theory of complements,introduced by Shokurov,for Calabi-Yau type varieties with the coefficient set[0,1].We show that there exists afinite set of positive integers N,such that if a threefold pair(X/Z∋z,B)has an R-complement which is klt over a neighborhood of z,then it has an n-complement for some n∈N.We also show the boundedness of complements for R-complementary surface pairs.
基金supported by National Science Foundation of USA (Grant Nos. DMS-1300750 and DMS-1265285)by a grant from the Simons Foundation (Grant No. 256202)
文摘Let(X, ?) be a log pair over S, such that-(KX+ ?) is nef over S. It is conjectured that the intersection of the non-klt(non Kawamata log terminal) locus of(X, ?) with any fiber Xs has at most two connected components. We prove this conjecture in dimension no greater than 4 and in arbitrary dimension assuming the termination of klt flips.
