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Abstract:The electricity industry is a basic industry of the national economy. It has experienced several large-scale power shortages, hard power shortage and soft power shortage, which have brought a great threat to China's sustainable economic development. To solve this problem better, it is necessary to make a quantitative assessment of the economic impacts of power shortage. The CGE model is commonly used for simulating economic shocks and policy effects. It describes supply, demand and equilibrium in different markets by simulating the economic mechanism through a set of equations. Once changed, the exogenous variables will affect a certain part of the system and then the whole system, leading to changes in quantities and prices. The equilibrium state will also change from one to another. A static CGE model is built in this paper, and the Social Accounting Matrix (SAM) of eight sectors of China in 2007 is compiled, in order to simulate the economic impacts of hard power shortage and soft power shortage. Simulation results show that the negative effects of power shortage on economic development are very significant, and the effects vary in different sectors. Especially, under the background of hard power shortage, the industrial sector suffers most. The economic cost of power shortage is considerable, and the main reason for it is the specific administrative pricing system in China. The low electricity price in the long term will lead to insufficient construction and hard power shortage; moreover, that in the short run would result in soft power shortage. In order to solve the problem of power shortage completely, power system reform is inevitable.

In this study, residual stress distributions and fatigue performances of electromagnetic driving dynamic cold expansion (DCE) open-holed sheets were investigated. Fatigue behaviors were tested, and residual stress fields were obtained experimentally and numerically. Furthermore, a fatigue life prediction method based on three-dimensional stress distribution was proposed. Results showed that DCE method extended higher fatigue life and produced more uniform residual stress along hole axial direction than static cold expansion (SCE) method. The stress distribution differences led to different fatigue crack initiation and propagation modes of DCE and SCE specimens. Uniform stress distributions along axial direction in DCE specimens contributed to random initiations and horizontal propagations of fatigue cracks, while the fatigue cracks in SCE specimens usually initiated at the mandrel entrance layer and propagated to the mandrel exit layer. Moreover, the predicted fatigue life results agreed well with experimental data.

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