The calculation and test of pH average value has paid more and more attention,and several calculation methods are pointed out.

Tests were made for the extractant dosage, phase ratio of organic phase to inorganic phase, extraction equilibrium pH value, extraction dynamics, extraction thermodynamics and stripping dynamics.

The annual average value and monthly mean value are obtained and compared to the concentrations of air ions outside the darkroom.

with the nature of the radial function of the hydrogen atom and the nature of the laguerre polynomials,the article deduced the formula that used to compute the average value of integer power (r~n) of the radial distance of the hydrogen atom-r.

Limitation and amelioration of the standard calculating method of pH average;

It adopts simple average PI regulator.

Describes the distributions, the average, the amplitude and time lags of indoor temperature measured from 144 living rooms or bedrooms of 98 households in Beijing during the summer of 1999.

The paper dealt with the defect of present value accounting,discussed the average value,distribution and marginal value of forest and pointed out the problems of ecological construction that should be paid attention to.