为探究吕家坨井田地质构造格局,根据钻孔勘探资料,采用分形理论和趋势面分析方法,研究了井田7......

This study describes the characteristics of mineral wool and its applications, and also introduces the traditional proce......

Let RP(k) denote the k-dimensional real projective space. This article determines which cobordism classes are represente......

本文研究了底空间为实射影空间时上协边类纤维丛表示的若干性质。...

In this paper, a quasilinear elliptic system is investigated, which involves concave-convex nonlinearities and nonlinear......