| http://www.w3.org/ns/prov#value | - In the formula I, m is an integral number having a value of 8 or more, and n is an integral number having a value of 18 or more, and R1 and R2 are selected from the group consisting of a hydrogen atom and an alkyl-group, and a mol ratio of a:b equals to 2:1-1:2, preferably, 1:1.
|
