Cahn—Hilliard方程的一类弱条件稳定的谱格式

研究一类非线性Ｃａｈｎ－Ｈｉｌｉａｒｄ方程的谱方法和拟谱方法，构造了一类弱条件稳定的全离散显式谱格式及拟谱格式．利用非线性函数有界延拓法和Ｓｏｂｏｌｅｖ不等式证明了格式的收敛性和稳定性．该拟谱格式为一显式，但具有隐格式的收敛精度与稳定性，容易在计算机上实现．最后给出数值结果．

Minimal Urysohn L fuzzy topological spaces and their properties

The concept of minimal Urysohn L fuzzy topological spaces is introduced and it is proved that an L fuzzy topological space is minimal Urysohn L fuzzy space if and only if it is Urysohn L fuzzy topological space and every Urysohn ideal base with and unique cluster point converges to that point by means of fuzzy Urysohn ideal base. Moreover it is proved that an minimal Urysohn L fuzzy topological space is not only an L fuzzy Urysohn closed space but also an L fuzzy semiregular space. The topological properties of minimal Urysohn L fuzzy topological spaces are investigated.