Determination of volatile organic compounds in water with retention time locking in gas chromatograph;

RP-HPLC method for calibrating the error of retention time of MTX;

Experiments showed that retention time of aniline was shortened with the increase of the concentration of methanol and chromatogram was improved along with the change of pH by the choice of suitable separated conditions,the optimum concentration of methanol was 30% and the optimum pH was 4.

By using multiple linear regression (MLR) method,the correlation relationship between the boiling point and the retention time on column with different polarity are studied for the volatile organic reagents with diverse structural groups.

The low phase noise and fast frequency switch lock time are the most important target of FH frequency synthesizer.

This paper analyses and simulates the lock time of the PLL frequency synthesizer,and gives the solution for various approaches to frequency-switching.

The phase recursive equation of loop on the triple-order loop for the first time has gained,and simulation is made on locked time with respect to the signals of both constant frequency and stepped frequency.

In DPLL design,locked time and locked range is a pair of contradictory.

A new architecture of charge pump for lowing locking time of phase locked loop (PLL) is proposed.