- The accurate formula of wire-injection value hasn't been proposed and it is operated by empirical value.
- The detailed deducing and accurate formula of coordination transformation are presented, the result is analysed and compared also.
- By assuming the weak lens focal length expression to be the first term in a power series, a simple and accurate formula can be derived for the objective focal length of a magnetic electron lens.
- For the characteristic of eccentrically loaded reinforced concrete column of ring section with bars in circular array,there is no accurate formula to calculate the ductility coefficient.
- According to the results of calculation and analysis,Colebrook formula is considered as a accurate formula,and approximate formulae only can be made rough calculation and mathematical analysis.