Highly-dispersed ZrO2 nanoparticles (NPs) were successfully synthesized via sol-gel and supercritical fluid drying (SCFD) method with zirconium oxychloride as the source. The as-synthesized ZrO2 was characterized by X...
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Highly-dispersed ZrO2 nanoparticles (NPs) were successfully synthesized via sol-gel and supercritical fluid drying (SCFD) method with zirconium oxychloride as the source. The as-synthesized ZrO2 was characterized by X-ray diffraction (XRD), high resolution transmission electron microscope (HRTEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetary (CV). The results indicate that the nearly spherical ZrO2 three-dimensional network NPs possess diameters of about 10nm, and the pure ZrO2 after SCFD treatment maintains uniform crystal structure while the 3Y-ZrO2 have many crystal defects. The electrochemical performance of ZrO2 NPs showed that the pure ZrO2 NPs after SCFD treatment have very small electrochemical impedance and well-performance of cyclical stability, which provide a new orient of lithium batteries materials.
This paper systematically investigates the surface reconstruction processes and patterns on stishovite SiO2, HfO2 and rutile TiO2 （001） by using classical molecular dynamics. It is found that these three surfaces re...
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This paper systematically investigates the surface reconstruction processes and patterns on stishovite SiO2, HfO2 and rutile TiO2 （001） by using classical molecular dynamics. It is found that these three surfaces relax instead of reconstruction at 0 K, and have little possibility to reconstruct below 40 K. Above 40 K, surface reconstructions take place as collective atomic motion which can be speeded by higher temperature or compressed strain. Several reconstruction patterns with approximate surface energies are found, and electrostatic potentials on them are also provided in comparison with possible microscopic results.
The photocatalytic degradation of *** membrane cell by ZnO nanowires was studied using field-emission scanning electron microscope（FE-SEM）,fluorescence microscopy,and Attenuated total reflection fourier transform in...
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The photocatalytic degradation of *** membrane cell by ZnO nanowires was studied using field-emission scanning electron microscope（FE-SEM）,fluorescence microscopy,and Attenuated total reflection fourier transform infrared（ATR-FTIR）.The outer membrane of *** was removed completely in the presence of ZnO nanowires under UV irradiation,and the cells became twisted shapes without a mechanically strong *** ZnO nanowires photocatalysis,the permeability of the treated cells increased to some degree that could be confirmed by quantum dots labeling *** changes in the cell wall membrane were revealed by the decay of the characteristic groups bands in ATR-FTIR spectra.
Dominant heat-carrying modes in skutterudites are associated with vibrations of the pnicogen rings. Apart from filling the structural cages with foreign species, disrupting the pnicogen ring structure by substitutiona...
Dominant heat-carrying modes in skutterudites are associated with vibrations of the pnicogen rings. Apart from filling the structural cages with foreign species, disrupting the pnicogen ring structure by substitutional alloying should be an effective approach to reduce thermal conductivity. In this paper we explore alloying configurations of pnicogen rings (Sb rings in the case of CoSb3) that yield particularly low values of the thermal conductivity. We find that IV-VI double substitution (replacing two Sb atoms with one atom each from the column IV and column VI elements to achieve an average charge of two Sb atoms) is a very effective approach. Our ab initio calculations, in combination with a cluster expansion, have allowed us to identify stable alloy configurations on the Sb rings. Subsequent molecular and lattice dynamics simulations on low energy configurations establish the range of atomic displacement parameters and values of the thermal conductivity. Theoretical results are in good agreement with our experimental thermal conductivity values. Combining both approaches of compensated double substitution and filling of structural cages should be an effective way of improving the thermoelectric figure of merit of skutterudites.
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.
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