The wage-tenure profile of the employees in Chinese service industry is obtained by using quadratic regression.

Second,the investing resources curve of aerospace high.

This paper presents the concept to use productivity model to analyze acidizing effect and discusses a comprehensive evaluation method for acidizing effect which is integrated with operation curves,production history curves,well test interpretation and productivity model analysis.

Discussion on some problems of the applying work curves in laboratory test;

Drawing work curve, digesting time and turbidity compensated are tested as determining total amount of P in surface water by ammonium molybdate tetrahydrate spectrophotometry.

The correction coefficient needs to be adopted to calculate the determinated value of work curve,it simplifies the operation,reduces error and enhances the accuracy and precision.

By trial and research,a set of SAE1141 standard specimens were developed and a constant performance curve was given.

Through inspection service comparing with the similar equipments precision of overseas companies, such as Spectro and ARL ect, the results show that the performance curve of DF-100 direct-reading spectrometer satisfies long-term use and doesn t need to be re-draw.