【简答题】In all forms of chromatography there is a mobile phase and a stationary phase. a) In thin layer chromatography what is the stationary phase? b) In thin layer chromatography what is the mobile phase?
【简答题】表达式 Not 13 Mod 3 = 1 Or 5 Mod 2 4的值是__________。
【判断题】The stationary phase of GC is solid.
【单选题】当x=8,m=-80时,表达式x/sqr(abs(x^2+m)的值是( ) 其中:sqr()为求平方根函数,abs()为求绝对值函数。例:sqr(9)=3,abs(-5)=5
【单选题】In normal phase partition chromatography, the stationary phase commonly used is ( )
【单选题】In HPLC, the principle for choosing the stationary phase is ( ).
A.
The difference in boiling point
B.
The difference in temperature
D.
The chemical stability
【单选题】表达式Int(2*sqr(36) +0.5)/3的值是( )。