Pointing to some irrational activities in assets appraisal of thermal power enterprises in China and combining with practice in assets appraisal form more than 10 years, the authors put forward to enhance the preparation of the early stage for the power assets appraisal to scientifically determine the economic life limit of power equipment.

Reasons of ionic membrane property degrading and analysis of its economic life;

Forecast of economic life of self-unloading truck used on construction site;

Analysis to economic life of marine diesels;

The algorithm of pumping unit's economical life is introduced systematically.

The paper expounded the calculative method and main indexes of economical life of the tractor.

To predict the economical life for pre-corrosion structures, the probabilistic fracture mechanics approach (PFMA) under pre-corrosion environment is presented.

Started with the conception of equipment renewal,several equipment renewal methods are introduced briefly,including lowest-fee method,MAPI method and economic lifetime method.

The best time limit of updating equipment is the economic lifetime of equipment.

By means of the breakeven principles of techno-economy,this paper makes a preliminary study on the method of determining economic lifetime of oil field s development projects It is hoped that this study will have certain guiding significance for correctly developing the techno-economic evaluation and decision-making work of such projects.

WT5BZ]The economic life span of air defence missile weapon and equipment has been analysed.

Under the hypotheses the model to calculate the economic life span of farm machines was established.

This text introduces the economic life span into the medical equipments management,and analyze the medical equipments relevant factors of the economic life span from two aspects,the analytical and economic life span settled in the medical equipments management.