Deciphering the Metal-Support Interaction of Au/ZnO Catalyst Induced by H2 and O2 Pretreatment.

Metal-support interaction (MSI) provides great possibilities to tune the activity, selectivity, and stability of heterogeneous catalysts. Herein, the Au/ZnO catalyst is prepared by commercial ZnO and chloroauric acid, and the structure evolution of the catalyst pretreated by H2 and O2 gas at varied temperature is investigated to provide mechanistic insights of MSI. It is found that the H2 treatment at 300 °C and above can induce the formation of both the ZnOx overlayer and bulk Au-Zn alloy. In contrast, the O2 treatment can form the ZnOx overlayer at 500 °C and above without the formation of Au-Zn alloy. It is also revealed that the ZnOx overlayer is dynamically stable (permeable), which can provide access for reactant molecules during the reaction process. And, the Au-Zn alloy can recover to Au and ZnO under the CO oxidation reaction condition, which can be deemed as a re-activation process that endows H2 -treated samples with the superior activity and stability.

Temperature Field in the Heat Transfer Process of PEEK Thermoplastic Composite Fiber Placement.

Under the effect of different process parameters, the temperature field inside the thermoplastic fiber is very complex and directly affects the fusion quality between the resins. Considering the heat transfer behavior of thermoplastic fiber polyether ether ketone (PEEK) as the research object, a mathematical model of heat transfer in the thermoplastic composite fiber placement with the relevant boundary conditions was established. Ansys Parametric Design Language (APDL) was used to generate the finite element model and simulate the transient process, not only to explore the influence of various process parameters on the temperature field, but also to build an online temperature field measurement system. The influence rules of placement process parameters and mold initial temperature with respect to the temperature field in the first layer were obtained. Combining the relationship between heating temperature and placement speed, when the first layer was laid, the placement process temperature could be quickly reached by low speed and high temperature. The temperature data were collected by the online detection system. Compared with the temperature data from the simulation, the error was below 8%, which verified the correctness of the heat transfer model. The academic research results will lay a theoretical foundation for the thermoplastic fiber placement.

Mechanical Simulation of Thermoplastic Composite Fiber Variable-Angle Laminates.

By changing the placement angle of the placement path, the fiber direction can be controlled and adjusted to change the load distribution in the laminate, and the stress and natural frequency performances of the laminate can then be altered to finally obtain laminates with desired mechanical properties. In this paper, the finite element analysis model of variable-stiffness laminates is established based on the fiber placement reference path defined by the Bezier curve method. Based on the analysis of the mechanical properties of the thermoplastic fiber variable-angle laminates obtained by variable-angle trajectory planning, the changes in the stress and deformation of the thermoplastic fiber variable-angle laminate with the connection point parameter ß under a compressive load are analyzed. The influence of the parameter ß on the static performances of the variable-angle laminates is studied. The simulation results indicate that the maximum stress of the laminate increases first and then decreases as the parameter ß increases and reaches the maximum value when the parameter ß is 0.5. The minimum stress also shows the same trend as that of the maximum stress and reaches the minimum value when the connection point parameter ß is 0.3. The deformation of the variable-angle laminates varies with the change of the connection point parameter ß. The maximum deformation increases at first and then decreases for the laminate with the parameter ß increasing and reaches the maximum value when the parameter ß is 0.8. The minimum deformation of the laminate decreases initially and then increases as the connection point parameter ß increases and reaches the minimum value when the parameter ß is 0.6. The deformation gradually decreases from the upper and lower ends to the middle, and the deformation area has a symmetrical form. The initial regular rectangular area gradually changes to an elliptical distribution and the area of maximum deformation gradually decreases.

Asymmetrical Induced Charge Electroosmotic Flow on a Herringbone Floating Electrode and Its Application in a Micromixer.

Enhancing mixing is of significant importance in microfluidic devices characterized by laminar flows and low Reynolds numbers. An asymmetrical induced charge electroosmotic (ICEO) vortex pair generated on the herringbone floating electrode can disturb the interface of two-phase fluids and deliver the fluid transversely, which could be exploited to accomplish fluid mixing between two neighbouring fluids in a microscale system. Herein we present a micromixer based on an asymmetrical ICEO flow induced above the herringbone floating electrode array surface. We investigate the average transverse ICEO slip velocity on the Ridge/Vee/herringbone floating electrode and find that the microvortex generated on the herringbone electrode surface has good potential for mixing the miscible liquids in microfluidic systems. In addition, we explore the effect of applied frequencies and bulk conductivity on the slip velocity above the herringbone floating electrode surface. The high dependence of mixing performance on the floating electrode pair numbers is analysed simultaneously. Finally, we investigate systematically voltage intensity, applied frequencies, inlet fluid velocity and liquid conductivity on the mixing performance of the proposed device. The microfluidic micromixer put forward herein offers great opportunity for fluid mixing in the field of micro total analysis systems.

Detecting the location and significance of Ezrin protein expression in hepatocellular carcinoma.

To explore the characteristics of localization and prognostic implication of Ezrin expression in HCC, 92 cases of HCC meeting strict follow-up criteria were selected for immunohistochemical staining of Ezrin protein. Correlations between Ezrin expression and clinicopathological features of HCC were evaluated using Chi-square tests, survival rates were calculated using the Kaplan-Meier method, and the relationship between prognostic factors and patient overallsurvival was analyzed using Cox proportional hazard analysis. In results, Ezrin protein was mainly expressed in the inner side of the cell membrane of the adjacent non tumor tissues, and diffusely expressed in cytoplasm of HCC tissues. There was an obviously difference between the benign and malignant tissues about the location of Ezrin expression. Ezrin strong-expression rates were significantly higher in HCC samples compared with the adjacent non tumor tissues (P<0.05). The Ezrin strong-expression rate was closely related with the differentiation (P<0.01), AJCC stage and metastasis of HCC (P<0.05, respectively). Therefore, the sub-cellular localization of Ezrin protein in the liver cells will be changed in the process of the transformation from the benign to malignant, and Ezrin plays an important role in the progression of HCC.