Anchored periplasmic expression (APEx) technology aims to express and localize proteins or peptides in the Escherichia coli periplasm. Some reports have suggested that transmembrane segments of integral membrane prote...
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Anchored periplasmic expression (APEx) technology aims to express and localize proteins or peptides in the Escherichia coli periplasm. Some reports have suggested that transmembrane segments of integral membrane proteins can be used as membrane anchors in the APEx system. In this study, a series of hydrophobic anchors derived from the first putative transmembrane helix of a Bacillus subtilis integral membrane protein, MrpF, and its truncated forms were investigated for anchored periplasmic expression of alkaline phosphatase (PhoA) in E. coli. Anchoring efficiency of hydrophobic anchors was evaluated by monitoring the expression and activity of anchored PhoA. The length of hydrophobic anchors was found to be critical for anchoring proteins to cell membranes. This study may open new avenues for applying transmembrane segments derived from native membrane proteins as membrane anchors in the APEx system.
Two types of Mg-Cu composition system graded density impactors used for complex loading （shock loading and quasi-isentropic compression） are designed by the elastic-plastic hydrodynamic method in this paper. Mixture...
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Two types of Mg-Cu composition system graded density impactors used for complex loading （shock loading and quasi-isentropic compression） are designed by the elastic-plastic hydrodynamic method in this paper. Mixtures of metal powders in the Mg-Cu system are cast into a series of 17 and 25 uniform compositions ranging from 100% Mg to 100% Cu. The graded den- sity impactors are launched to the stationary 10 Ixm aluminum film and 12 mm LiF window targets by a two-stage light-gas gun in the National keylaboratory for Shock Wave and Detonation Physics Research, Institute of Fluid Physics, CAEP, and the resulting wave profiles are measured with the DISAR system. Hydrodynamic simulation results are perfectly consistent with the experiments. Our work in this paper will set up a foundation for further research of controllable loading/releasing routes and rate experiments in the future.
A high effective non-consumable double electrode GMAW (Gas Metal Arc Welding) method is presented. A dynamic mathematics model for decoupling welding arc was developed adopting the method of equivalent current path ac...
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A high effective non-consumable double electrode GMAW (Gas Metal Arc Welding) method is presented. A dynamic mathematics model for decoupling welding arc was developed adopting the method of equivalent current path according to the arc dynamic characteristics of non-consumable DE-GMAW process. Then the process of non-consumable DE-GMAW process was simulated and analyzed by MATLAB/Simulink. The results show that the developed mathematics model can reflect the DE-GMAW process well, and higher efficiency than conventional GMAW and lower spatter can also be ensured.
Nb-Si system in-situ composites with nominal composition of Nb-21Ti-16Si-7Cr-3Al-2Hf（mole fraction,%） were prepared by directional solidification technology in an optical floating zone furnace at the growth rates of...
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Nb-Si system in-situ composites with nominal composition of Nb-21Ti-16Si-7Cr-3Al-2Hf（mole fraction,%） were prepared by directional solidification technology in an optical floating zone furnace at the growth rates of 3,5,8 and 12 mm/*** microstructures and mechanical properties were investigated as a function of the growth *** results show that the solidification microstructures consist of Nb solid solution（Nbss）,α-Nb5Si3andβ-*** with high aspect ratio grow continuously and straightly when the growth rate is 5mm/h;lower or higher growth rates are disadvantageous for the formation of favorable directional *** compressive strength at 1 250℃and room-temperature fracture toughness of the specimen with the growth rate of 5 mm/h that exhibits excellent mechanical properties are 415 MPa and 22.4 MPa·m1/2,respectively.
The fabrication of well defined hierarchical structures of anatase TiO_(2) with a high percentage of reactive facets is of great importance and *** flower-like TiO_(2) superstructures(HFTS)self-assembled from anatase ...
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The fabrication of well defined hierarchical structures of anatase TiO_(2) with a high percentage of reactive facets is of great importance and *** flower-like TiO_(2) superstructures(HFTS)self-assembled from anatase TiO_(2) nanosheets with exposed{001}facets(up to 87%)were synthesized by a simple alcohothermal strategy in a HF-H_(2)O-C_(2)H_(5)OH mixed solution using titanate nanotubes as *** samples were characterized by X-ray diffraction,scanning electron microscopy,transmission electron microscopy,and N2 adsorption-desorption *** photocatalytic activity was evaluated by the photocatalytic oxidation decomposition of acetone in air and methyl orange in aqueous solution under UV *** photocatalytic activity of HFTS was much higher than that of commercial Degussa P25 and tabular-shaped anatase TiO_(2) obtained using pure water as the synthesis *** enhancement in photocatalytic activity was related to several factors,including the hierarchically porous structure,exposed{001}facets,and increased light harvesting *** HFTS was also of interest for use in solar cells,photocatalytic H_(2) production,optoelectronic devices,sensors,and catalysis.
The equilibrium of the solid-liquid interface in pressurized solidification process of binary alloys was studied using the Gibbs theory, and the stability of the solid-liquid interface was discussed based on the consi...
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The equilibrium of the solid-liquid interface in pressurized solidification process of binary alloys was studied using the Gibbs theory, and the stability of the solid-liquid interface was discussed based on the consideration of the effects of pressure on the diffusion coefficient, the interface growth rate and tile equilibrium liquid composition. A mathematical description of the equi- librium status, the relationship of temperature, pressure, composition and interfacial tension was obtained, and further, a mathematical representation of the curvature radius of solid-liquid interface was developed, which facilitates a thorough understanding of the controlled variables of the interfacial stability.
Aimed at GMAW-P welding process instability and weld bead appearance poor problems caused by welding arc load nonlinear and strong time-varying, a mathematical model of GMAW-P between wire speed, welding current and a...
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Aimed at GMAW-P welding process instability and weld bead appearance poor problems caused by welding arc load nonlinear and strong time-varying, a mathematical model of GMAW-P between wire speed, welding current and arc length had been set up. A controller based on D-FNN algorithm had been designed. Simulation of arc length dynamic varying was studied using this controller after changing the wire speed and welding average current. The result of simulation indicated that the D-FNN controller can control the arc length change. Also this controller has fast response speed and robustness, can meet the welding process stability of arc length of real-time control request. For controlling GMAW-P welding arc stability provides a new method.
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