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Room temperature liquid metals (LM) such as gallium (Ga) own the potential to react with specific materials which would incubate new application categories. Here, diverse self-organized ring patterns due to nonequilibrium reaction-diffusion and spreading-limitation of Ga-based LM clusters on gold (Au) film are reported, among which diffusion is the controlling step and the self-limiting oxide layer plays the role of kinetic barrier. Such phenomena, classically known as the Liesegang rings, mainly occurred in electrolyte media. Unlike existing systems, the present periodic crystallization mechanism enables highly symmetric spatiotemporal periodic Liesegang rings on a smaller scale under ambient conditions. Typically, the Ga-Au and eutectic gallium-indium alloy (EGaIn)-Au reaction-diffusion-spreading systems are constructed, obtaining the revert type and hybrid type concentric Liesegang patterns, respectively. Competitive patterning behavior of the intermediate phase products AuGa

In order to investigate the influence of different deformation routes of equal channel angular pressing (ECAP) on mechanical properties and microstructure of AA6063 alloy at room temperature. The specimens were processed with angle of 120°regarding processing routes A, BA, BC, BC-UD2 and C. Then the macro morphology of specimens was analyzed, the strength and hardness were measured, and the microstructure was observed by SEM. The results show that, after four passes, the deformation of route A is the most inhomogeneity, while route BC-UD2 is the most homogeneity. Route BC deformation is relatively uniform and not easy to generate cracks on up-surface. The increase of tensile strength of route BC and route C is the most. The ductility of route BA and route BC keep best. Route BC can not only improve the strength of the material, but also maintain the plasticity of the material. The hardness improvement and the deformation uniformity show negative correlation under in all routes. The hardness improvement is most obvious after route BA, and the deformation is most homogeneous after route BC-UD2. The microstructure of route C and route BC is equiaxed grain. The average grain size of specimens is smaller after route C.

Equal channel angular pressing (ECAP) is one of the methods to prepare ultrafine-grained materials by sever plastic deformation. The materials with large grain size can be extruded at room temperature. The present work investigates the influence of different deformation routes on microstructure evolution and electrical conductivity at room temperature of ECAP processed AA6063 sample. Samples were processed with four different routes (A, BA, BC and C) in the ECAP die. The microstructure and electrical conductivity of the specimen after ECAP were measured. The results show that with the increase of extrusion passes, ECAP can fragment the large AlFeSi phase to small particles (length (1−3)μm) and homogenize the small particles. After four passes of ECAP, the grain of the sample is refined, and the grain size is about 0.55μm. The order of average grain size from small to large is C BC > C.

In the present work, the gas flow pressure drop and gas–solid heat transfer characteristics in sinter bed layer of vertical tank were studied experimentally on the basis of the homemade experimental setup. The gas flow pressure drop through the sinter bed layer was measured with different gas velocity and particle diameters, as well as the sinter and air temperatures. The influences of gas superficial velocity and particle diameter on the gas flow pressure drop and gas solid heat transfer in sinter bed layer were analyzed in detail. The revised Ergun’s correlation and gas solid heat transfer correlation were obtained according to the regression analysis of experimental data. It is found that, the pressure drop of unit bed layer height gradually increases as a quadratic relationship with increasing the gas superficial velocity, and decreases as an exponential relationship with the increase of sinter particle diameter. For a given sinter temperature, the heat transfer coefficient in sinter bed layer increases with increasing the gas superficial velocity, and increases with decreasing the sinter particle diameter. In addition, the heat transfer coefficient also gradually increases with increasing the sinter temperature at the same gas superficial velocity and sinter particle diameter. The mean deviations between the experimental data obtained from this work and the values calculated by the revised Ergun’s correlation and the experimental heat transfer correlation are 7.22% and 4.22% respectively, showing good prediction.

In the real world, various applications can be modeled as large-scale label graphs, which labels can be represented the feature of nodes. Subgraph query is a problem of finding isomorphism subgraphs that satisfy the query conditions, which has attracted much attention in recent years. Therefore, a subgraph query method based on adjacent node features on large-scale label graphs with fewer label categories was proposed in this paper. The method consists of two phases, which are offline index creation and online query. Firstly, we introduce a data structure to describe the information of nodes by scalar features. Secondly, we propose a three-level star structure features index include adjacent nodes’ label category, the degree of star-centered and the number of each label, which is named adjacent node scalar features index (ANSF index). After that, according to the structure of query graph is star structure or not, we proposed two different processing strategies on the phase of online query. Experimental results show the efficiency and the effectiveness of the proposed method in index creation time, space usage and subgraph query.

The examination of exergy transfer characteristics caused by gas-solid heat transfer through sinter bed layer in vertical tank has been presented. Correlations involving relevant variables to predict the mean exergy transfer coefficient, the mean exergy transfer Nusselt number and the non-dimensional exergy flux have been derived by applying the second law of thermodynamics and non-equilibrium thermodynamics theory. The relationships of mean exergy transfer Nusselt number with the heat transfer Nusselt number, Reynolds number, the non-dimensional heat flux and the non-dimensional pressure drop are determined. The experimental results of exergy transfer characteristics in sinter bed layer with different gas superficial velocity, sinter particle diameter and bed layer height are obtained from homemade gas-solid heat transfer setup, and the effects of air outlet temperature, non-dimensional temperature and Reynolds number on the exergy transfer characteristics are analyzed. The research results show that for a given experimental condition, the mean exergy transfer Nusselt number gradually decreases with the increase of Reynolds number and sinter bed layer height. The mean exergy transfer Nusselt number would be less than zero for a lower air outlet temperature, which is pointless for gas-solid heat transfer process in sinter bed layer.

In the present paper, a three-dimensional mathematical model is established on the basis of the porous media theory and the local thermal non-equilibrium model, to investigate the gas solid heat transfer in sinter bed layer of vertical tank. The reliability of mathematical model is verified through the comparison of calculated results with the experimental results according to the homemade experimental setup. Numerical simulations are conducted to examine the influences of different structural and operating parameters on the air and sinter temperatures in sinter bed layer. Furthermore, an optimal combination of each parameter is determined through the orthogonal experiment for improving the outlet exergy of cooling air. The results show that the outlet air and sinter temperatures decrease with the air flow rate increasing. Decreasing the inner diameter and height of cooling section, or increasing the particle diameter, the outlet air temperature decreases and the outlet sinter temperature increases. Based on the sinter annual output of 3,900,000 tons for 360 m2 sintering machine, the suitable structural and operating parameters of vertical tank are 150 kg/s for the air flow rate, 0.015 m for the sinter particle diameter, 10 m for the inner diameter of cooling section and 8 m for the height of cooling section.

This work experimentally investigates the gas–solid heat transfer behavior in vertical tank for sinter waste heat recovery. With the purpose of predicting the heat transfer Nusselt number, a homemade experimental setup is built to obtain the temperatures of cooling air and sinter particles over time. Sinter particles of average diameter d = 18, 27 and 36 mm with a range of sphericity of 0.68 ≤ Φ ≤ 0.89 are used in the experiments. The experiments are performed in the range of gas superficial velocity of 1.04~1.75 m/s and the sinter temperature in bed layer from 100 to 750 °C. The influences of gas superficial velocity and sinter particle diameter on the gas–solid overall heat transfer coefficient are analyzed in detail for the covered test cases. The heat transfer Nusselt number is obtained according to the regression analysis of experimental data, and the reliability of the heat transfer Nusselt number is also verified. It is found that the gas–solid overall heat transfer coefficient increases with the increase of gas superficial velocity, and decreases with increasing sinter particle diameter. A small increase in gas–solid overall heat transfer coefficient with the temperature of sinter particles is also observed in the experiments. Compared with the previous literature correlations, the experimental correlation for gas–solid heat transfer in the form of Nusselt number best fits the experimental data. The mean deviation between the experimental data of Nusselt number obtained from this work and the values calculated by the experimental heat transfer correlation is 4.37%, showing good prediction.

In the present study, the dimensionless method of Ergun's correlation is used to investigate the flow regimes and the pressure drop characteristics in the packed beds with non-spherical sinter particles. The sinter particles of average diameter d = 6, 14, 24 and 35 mm, with a range of sphericity, 0.63≤ Φ ≤ 0.89 are used in random packing with the range of bed layer voidage, 0.423≤ e ≤ 0.53. The pressure drop of unit bed layer height in the packed bed is measured with particle Reynolds number (Re p ) ranging from 96 to 6888. The influences of gas superficial velocity and particle diameter on the pressure drop are analyzed in detail for the covered test cases. The critical Reynolds numbers marking transition among flow regimes and the revised Ergun's correlation are obtained according to the slope change of the f p – Re p curve and the regression analysis of experimental data. The reliability of the revised Ergun's correlation is also verified. It is found that, the pressure drop of unit bed layer height gradually increases as a quadratic relationship with increasing gas superficial velocity for a given particle diameter. The pressure drop of unit bed layer height decreases as exponential relationship with the increase of particle diameter for a given gas superficial velocity. The air flow in vertical tank with sinter particles is under non-Darcy flow area for the actual condition and the critical Reynolds number marking transition from Forchheimer flow to turbulent flow in sinter bed layer increases as a third order relationship with increasing particle equivalent diameter. Compared with the previous Ergun's correlations, the revised Ergun's correlation is able to fit the whole experimental data best, and the mean deviation between the experimental data and the values calculated by the revised Ergun's correlation is 7.22%, showing good prediction.