Semi-colonialism and semi-feudalism is a multiple so cial and economic structure containing five economic sectors including foreign i nvestment,feudal landlord economy,private economy and the new democratic economy .

Compares low-temperature radiant floor heating systems with common radiator heating systems by economic cost analysis and exergy analysis.

As is shown in historical development,it is likely to have a unified viewpoint of righteousness and profit when diverse economic elements coexist.

Research on Economic Cost of Natural Resources Assets from the View of Rights and Interests Achievement of Different Objects;

The paper points out the present fixed exchange-rate system has alredy hindered the convey of policies and is not adaptable to the present macroeconomic situation after analyzing its economic cost and the effect of the macroecomic policies, and draws a conclusion according to the swan model that presently the truly managerial floating exchange-rate system is the optimal choice.

There is a defect in classical model,Geometric Brown Motion,in which random jump is not allowed in describing time varying stock price some random jump were added to Geometric Brown Motion and the effect of executive stock option on economic value of company economic cost as well as executive,s economic value were discussed.