With the popularity of electric vehicles, a large number of charging stations connected to the grid, will bring about tremendous influence on the power, voltage and current of grid. This paper briefly introduces several common types of charging mode, and analyzes the characteristics of them. According to statistics, a resistive model of charging stations, simulating the regional power grid with a IEEE34 node model, has been established to forecast the daily load curve, using Monte Carlo simulation. An analysis is performed for a power grid to demonstrate the impacts of the daily load curve considering different power of charging stations, which are under coordinated charging conditions, to indicate the harm of uncoordinated charging and put forward solutions.

Effect of multi-section linear non-uniform heat transfer coefficient on quenching residual stress distribution in 27mm-thick Al-Zn-Mg-Cu aluminum alloy plate was simulation studied by using the finite element method, and the surface quenching residual stress distribution was measured by the X-ray diffraction method and hole-drilling method. The results show that the surface quenching residual stress represents the same distribution with non-uniform heat transfer coefficient in the transverse direction and the stress level maintains initial stress level of the heat transfer coefficient at each location. The distribution of the quenching residual stress in the center of the plate is approximately uniform and the stress level is approximately equal to average of maximum and minimum initial stress level. The measured surface quenching residual stress shows a wavy distribution in the transverse direction, which is similar to the simulated surface stress distribution without considering the stress level. The measurement results can be explained by the multi-section linear non-uniform quenching model.

We investigate the gas transport enhancement through nanotubes, relative to the prediction by the prevailing century-old Knudsen diffusion model. This enhancement is usually attributed to the partly specular molecular reflections at the smooth nanotube surface, which break the model assumption of completely diffusive reflections. However, an oversighted cause of the discrepancy between the measurement and theory that we found is that even for the gas transport with completely diffusive reflections, the Knudsen diffusion model based on Fick's first law is accurate only for long nanotubes. Additionally, for smooth nanotubes with partly specular reflections, the Knudsen diffusion model is also invalid even if the diffusion coefficient is corrected to account for the atomic-scale surface smoothness. On the other hand, the Knudsen diffusion model might be used for interpretations instead of predictions, and then the diffusion coefficient inferred from the measured mass flow rate could be completely different from the actual value. All those discrepancies and confusions stem from the implementation of Fick's first law can be avoided by using the molecular transmission probability obtained by the kinetic theory to quantify the flow rate of the Knudsen diffusion process. This work provides the correction to the Knudsen diffusion model for accurate predictions of gas diffusion through nanotubes and better interpretations of experimental measurements.

With the development of economy, steel structure is more and more widely applied in China. With the deepening of sustainable development, the industrialization of construction become more and more hot in construction industry. Steel Structure is expected to be an important building material of industrialization. Obviously steel structure has been a main forms using in China. According to the characteristics of steel structure, smart material of BIM and RFID can be chosen as a new integration. This smart material can be used to solve the key technology of lifecycle management and information is shared, exchange with each other between participants during each stage.

An innovative spray deposition technique has been applied to produce in situ TiB2/Zn-30Al-1Cu composites. The microstructures of the spray-deposited composite were studied using scanning electron microscopy, transmission electron microscope and X-ray diffraction. The results have shown that the TiB2particulates are formed in the microstructure. It was found that the TiB2particles were distributed in Zn-30Al-1Cu matrix uniformly, and the TiB2particles are about 2μm in size.