The energy transfer (ET) between f-f transition is achieved by rare earth ions (RE 3+ ) doped grain boundaries of transparent ceramics, which enhances the fluorescence thermometry performance and enables multiple fluo...
The energy transfer (ET) between f-f transition is achieved by rare earth ions (RE 3+ ) doped grain boundaries of transparent ceramics, which enhances the fluorescence thermometry performance and enables multiple fluorescence thermometry modes of transparent ceramics. In this work, MgAlON:Dy 3+ transparent ceramics were prepared and segregation of Dy 3+ in grain boundaries was realized. With excellent absolute and relative sensitivities (2.447 μs/K and 2.09%/K), the fluorescence lifetime (FL) signals of MgAlON:Dy 3+ exceeds most of RE 3+ doped phosphors. The ET between closely segregated Dy 3+ in grain boundaries modifies the distribution of electron on 4 I 15/2 level, and induces temperature-dependent FL to the phosphors. This work reveals the influence of grain boundary segregation on ET between Dy 3+ for improving the fluorescence thermometry performance of phosphors.
The misfolding of amyloid-β(Aβ) peptides from the natural unfolded state to β-sheet structure is a critical step, leading to abnormal fibrillation and formation of endogenous Aβ plaques in Alzheimer's diseas...
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The misfolding of amyloid-β(Aβ) peptides from the natural unfolded state to β-sheet structure is a critical step, leading to abnormal fibrillation and formation of endogenous Aβ plaques in Alzheimer's disease(AD). Previous studies have reported inhibition of Aβ fibrillation or disassembly of exogenous Aβ fibrils in vitro. However, soluble Aβ oligomers have been reported with increased cytotoxicity; this might partly explain why current clinical trials targeting disassembly of Aβ fibrils by anti-Aβ antibodies have failed so *** we show that Au23(CR)14(a new Au nanocluster modified by Cys-Arg(CR) dipeptide) is able to completely dissolve exogenous mature Aβ fibrils into monomers and restore the natural unfolded state of Aβ peptides from misfolded β-sheets. Furthermore, the cytotoxicity of Aβ40fibrils when dissolved by Au23(CR)14is fully abolished. More importantly, Au23(CR)14is able to completely dissolve endogenous Aβ plaques in brain slices from transgenic AD model mice. In addition, Au23(CR)14has good biocompatibility and infiltration ability across the blood–brain barrier. Taken together, this work presents a promising therapeutics candidate for AD treatment, and manifests the potential of nanotechnological approaches in the development of nanomedicines.
Shock responses of Mg-Al-Zn alloy are investigated by the molecular dynamics(MD)*** wave propagation,plastic deformation behavior and failure mechanism along the[0001]and[1010]orientations are *** both orientations,si...
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Shock responses of Mg-Al-Zn alloy are investigated by the molecular dynamics(MD)*** wave propagation,plastic deformation behavior and failure mechanism along the[0001]and[1010]orientations are *** both orientations,simulation results show that the shock wave has an obvious double-wave structure(plastic-elastic)under a piston velocity of 1200 m/s.A higher Hugoniot elastic limit(HEL)is observed for[0001]-oriented *** the shock pressure is along the[1010]direction,the distance between plastic and elastic waves is closer,and higher dislocation density and more twins are ***,the spall strength for[1010]-oriented shock is predicted to be *** addition,the wave interactions,HEL and spall strength predicted for Mg-Al-Zn alloy are compared with the experimental results and MD simulation results of Mg single crystal in the *** is concluded that the shock performance of Mg-Al-Zn is better than that of Mg single crystal.
The present work proposes a novel strategy to fabricate an integrated architecture of gel polymer electrolyte (GPE)-nanoarray cathode for lithium-O2 batteries (LOBs). As a proof-of-concept experiment, the photo-in...
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The present work proposes a novel strategy to fabricate an integrated architecture of gel polymer electrolyte (GPE)-nanoarray cathode for lithium-O2 batteries (LOBs). As a proof-of-concept experiment, the photo-initiated in situ polymerization of GPE was carried out via incorporating the precursor solution in advance into a self- standing binder-free oxygen electrode of Co3O4 nanosheets array grown on carbon cloth (Co3O4@CC), forming an integrated GPE-Co3O4@CC architecture. The performance of the solid-state LOBs using the GPE-Co3O4@CC assembly is greatly enhanced compared to the counterparts with a traditional cell structure, in which GPE was sandwiched by a lithium metal and a cathode. The enhanced performance is ascribed to the combination of the in situ polymerization of GPE and the versatile structure of nanoarray electrode, which results in abundant interfacial contacts between GPE and electrode. This work presents an alternative way to develop high-performance solid-state LOBs by combining the advantages of both gel polymer electrolytes and nanoarray electrodes.
The structure and properties of Mg-doped SrBi4Ti4O15(SBT) were dicussed. Mg substitution into SBT had two possibilities states with the dopant amount variety. Mg cation substituted mostly into Sr^2+ and the amount ...
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The structure and properties of Mg-doped SrBi4Ti4O15(SBT) were dicussed. Mg substitution into SBT had two possibilities states with the dopant amount variety. Mg cation substituted mostly into Sr^2+ and the amount proportion was 68.11%.Mg ion will substitute into Ti ion site in perovskite layer when the doping amount increases. Polarization increases sharply when x=0.1 and then decreases becauses of the domain pinning. The Curie temperature of Mg-doped SBT is about 300 ℃ and there is a broad diffuse phase transition near Tc with a flat peak near the Ta of SBT.
Combustion synthesis of titanium diboride(TiB2) from titanium(Ti) and boron(B) powders was studied by theoretical calculation and experimental analysis. In high temperature range or in low temperature range, the calcu...
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Combustion synthesis of titanium diboride(TiB2) from titanium(Ti) and boron(B) powders was studied by theoretical calculation and experimental analysis. In high temperature range or in low temperature range, the calculated activation energies are 140KJ/mol or 355KJ/mol respectively, which is described by a change from dissolution-precipitation controlled process to diffusion-controlled process. With the increase of particle size of the raw materials, combustion temperature and propagating rate will both reduce. The propagating rate decreases with the addition of diluents. Further increase of diluents may result in a stop of the combustion wave halfway or even a failure of ignition.
The aim of this work was to prepare MgF2 translucent ceramic by using nanopowders as raw materials and to study its *** MgF2 nanopowders were prepared using chemical precipitation and the translucent ceramics were fab...
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The aim of this work was to prepare MgF2 translucent ceramic by using nanopowders as raw materials and to study its *** MgF2 nanopowders were prepared using chemical precipitation and the translucent ceramics were fabricated by hot-pressing sintering in a vacuum environment. X-ray diffraction analysis showed that the powders were homogeneous with an average particles size about 13 nm. By comparing the results of transmission electron microscopy, it could be concluded that the porous structure of precursor powders could be improved by calcination. The SEM images of MgF2 indicated that the as-prepared ceramics were well densified at 900 ℃. The photo of the ceramic sample showed that high translucence is a main breakthrough in the field of MgF2 materials preparation. For the translucent ceramic sample sintered at 900 ℃, the Viekers hardness and density were 5.55 GPa and 98.74%, respectively, and its highest transmittance with thickness of lmm reached 87% in the wavelength from 2.5 lain to 10 btm, all which made it advantageous to be a kind of infrared windows and dome materials.
Two kinds of azo polysemicarbazides were prepared based on 3,3'-azobis(benzoylhydrazide)(ABH) and two kinds of diisocyanates via solution *** structures were characterized by Fourier-transform infrared(FT-IR) t...
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Two kinds of azo polysemicarbazides were prepared based on 3,3'-azobis(benzoylhydrazide)(ABH) and two kinds of diisocyanates via solution *** structures were characterized by Fourier-transform infrared(FT-IR) technique and elemental *** viscosities of the polymers were 0.32 and 0.29 dL/g and both could be dissolved in H2SO4 and polar organic *** gravimetric analysis(TGA) presented a multi-step degradation and a decomposition temperature range of 230-280 ℃.And photoisomerization of the azo polymers in solvent of N,N-dimethyl acetamide(DMAc) was confirmed by Ultraviolet-visible spectroscopy(UV-Vis),suggested the isomerization appearing under the ultraviolet irradiation at 365 nm and recovering completely by visible light irradiation or kept in the *** electron microscopy(TEM) of polysemicarbazides before and after soaking in bovine serum albumin(BSA) solution confirmed the biocompatibility of azo polymers.
TiAIN solar selective absorbing coatings which were deposited on 304L stainless steel using cathodic arc evaporation method were annealed under non-vacuum at different temperatures with different times. The optical pr...
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TiAIN solar selective absorbing coatings which were deposited on 304L stainless steel using cathodic arc evaporation method were annealed under non-vacuum at different temperatures with different times. The optical properties (absorptance and emittance) of the coatings were measured by a spectrophotometer. It was found that, after being annealed for 2 hours at different temperatures, the absorptance of the coatings reached the highest value of 0.92 at 700 ℃ while the emittance got the lowest value of 0.38 at 800 ℃. When the coatings were annealed at 600 ℃ for 24 hours, the optical properties changed to 0.92/0.44 (absorptance/ emittance). By measuring the structure, morphology, elements and surface roughness of the coatings, it was found that both the elemental composition and the surface roughness of the coatings changed as a result of annealing, and these changes caused the change of the optical properties of the coatings.
Infrared radiant powder was synthesized by conventional ceramic processing techniques by using Fe2 O3, MnO2, CuO, Co2 O3 and kaolin as raw materials. A novel infrared radant glaze was developed by introducing the infr...
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Infrared radiant powder was synthesized by conventional ceramic processing techniques by using Fe2 O3, MnO2, CuO, Co2 O3 and kaolin as raw materials. A novel infrared radant glaze was developed by introducing the infrared radiant powder into glazing as a functional additive. Infrared radiant characteristics of the powder and the glaze were investigated. The optimum content of infrared radiant powder in glazing was ascertained to be 5% . The infrared radiant glaze exhibits significant antibacterial and antifungal Junctions due to the thermal effect of infrared radiation. Antibacterial percentages of the glaze reach 91% - 100% when Escherichia coli, Staphylococcus aureus and Bacillus subtilis are used as model bacterium respectively, while antifungal percentage of the glaze exceeds 95% when Penicillum citrinum is used as model fungus.
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