We develop the conception of simple interest,compound interest and continuous compound interest,and prove that the continuous compound interest is maximum and the simple interest is minimum,real rate of interest is more than nominal interest rate,further,the range and quality of the continuous compound interest are developed.

This article analyzes some relative data about the deposit problem by means of the simple interest method and compound interest method resptectively so as to make an active significance for deposit in reality.

This paper discusses the problems of the students Bank Credit Loan from the point of the time value of money, and shows how to calculate students cash flow statement under the condition of the compound interest and simple interes

Based upon the economic concept of income to cost ratio Rn,the model for the analysis of economic profitability of multiple reuse of acidic bath for electroless Ni-P plating was established and interactions between the formulation of the plating, process and market factor were obtained.

Secondly, according to reuse experiment, deactivation and regeneration of caralyst were also studied.

A method of using vacuum characteristic of a nozzle to reuse the oil mist generated during machining operation was put forward.