Hubl number

例句：

1. 1.Hubl number is a mathematical concept that has been studied for decades.
   胡贝尔数是一种被研究了几十年的数学概念。
2. 2. In mathematics, Hubl numbers are used to describe the behavior of certain types of functions.
   在数学中，胡贝尔数被用来描述某些函数的行为。
3. 3. The study of Hubl numbers has led to important discoveries in the field of physics.
   对胡贝尔数的研究在物理学领域导致了重要的发现。