摘要 :
Microring resonators (MRRs) with ultracompact footprints are preferred for enhancing the light-matter interactions to benefit various applications. Here,ultracompact titanium dioxide (TiO2) MRRs with sub-10-μm radii are experimen...
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Microring resonators (MRRs) with ultracompact footprints are preferred for enhancing the light-matter interactions to benefit various applications. Here,ultracompact titanium dioxide (TiO2) MRRs with sub-10-μm radii are experimentally demonstrated. Thanks to the large refractive index of TiO_(2),the quality factors up to -7.9×10^(4) and -4.4×10^(4)are achieved for TiO_(2) MRRs with radii of 10μm and 6μm,respectively,which result in large nonlinear power enhancement factors (>113) and large Purcell factors (>56). The four-wave mixing(FWM) measurements indicate that,compared to the large MRR,the FWM conversion efficiency of the ultracompact TiO2 MRRs can be greatly improved (e.g.,-25 dB versus-31 dB),a harbinger of significant superiorities. Demonstrations in this work provide more arguments for the TiO_(2) waveguides as a promising platform for various on-chip photonic devices.
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摘要 :
An electrochemical method for the direct reduction of solid TiO2 was introduced,in which the oxygen is ionized,dissolved in the molten salt and discharged at the anode,leaving pure titanium at the cathode. Titanium was prepared fr...
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An electrochemical method for the direct reduction of solid TiO2 was introduced,in which the oxygen is ionized,dissolved in the molten salt and discharged at the anode,leaving pure titanium at the cathode. Titanium was prepared from TiO2 via molten salt electrolysis,and experimental process was studied in detail. The reductive products of TiO2 were analyzed through XRD,SEM,XPS and so on. The results indicate that titanium with high purity is obtained by the electrochemical reduction. Through thermogravimetric analysis of molten CaCl2,it is shown that the dehydration of CaCl2 has to be strictly controlled to eliminate hydrolysis. The cyclic voltammetry studies on the TiO2 cathode electrochemical system show that the reduction of TiO2 is conducted step by step,from exterior to interior and from high-valence to low-valence. The conclusions were also confirmed by study on thermodynamics analysis. The current efficiency can be improved by loading different voltages in different stages.
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Photocatalytic reduction of CO2 to organic compounds was reduction in semiconductor suspension system under simulated solar in laboratory. TiO2 load catalysts were prepared in different ways, and they were used in photocatalytic r...
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Photocatalytic reduction of CO2 to organic compounds was reduction in semiconductor suspension system under simulated solar in laboratory. TiO2 load catalysts were prepared in different ways, and they were used in photocatalytic reduction of CO2 . Experimental results show that the photocatalytic activity can be improve by dressing Pd, Ru on TiO2 Surface and is obvious different when catalysts were prepared in different ways. The photocatalytic mechanism of dressing Pd on TiO2 Surface; dressing Pd and Ru on TiO2 Surface were also discussed in this paper.
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This paper describes a new process for producing titanium aluminides, in particular TiAl, from TiO2 raw material. On the basis of obtained results, the non-completed reaction of TiO2 with Al and Ca in a special reaction vessel res...
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This paper describes a new process for producing titanium aluminides, in particular TiAl, from TiO2 raw material. On the basis of obtained results, the non-completed reaction of TiO2 with Al and Ca in a special reaction vessel results in the production of granulates of titanium aluminides especially Ti3Al and other TiAl phases as the metallic product and Ca12Al14O33 as the non-metallic product. By adding KClO4 in the mixture, a nearly completed reaction can be carried out. The products of this reaction are titanium aluminide particularly TiAl as the metallic part and CaAl4O7 (grossite) as the non-metallic slag part. Both product and slag are produced in a separated form. This process, called KRH-method is described in this article.The scanning electron microscopic microstructure of metallic part of the product shows different phases: the matrix phase is TiAl, where the needle form precipitation is TiAl2 and the plate form precipitation includes TiAl and Ti3Al phases. The microstructure of the remelted metallic part indicates dendritic phase with a lamellar structure comprising of TiAl and Ti3Al phases. The interdendritic phase of TiAl is also seen.
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摘要 :
A wide variety of processes are being pursued by researchers for cost effective extraction of titanium metal. Electrochemical processes are promising due to simplicity and being less capital intensive. Some of the promising electr...
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A wide variety of processes are being pursued by researchers for cost effective extraction of titanium metal. Electrochemical processes are promising due to simplicity and being less capital intensive. Some of the promising electrochemical processes of titanium extraction were reviewed and the results of laboratory scale experiments on electrochemical reduction of TiO2 granules were brought out. Some of the kinetic parameters of the reduction process were discussed while presenting the quality improvements achieved in the experimentation.
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C60 carboxylic acid derivatives can be readily adsorbed on the surface of nanocrystalline TiO2 films act as charge-transfer sensitizer. The electron transport from TiO2 to the C60 derivatives results in the generation of the catho...
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C60 carboxylic acid derivatives can be readily adsorbed on the surface of nanocrystalline TiO2 films act as charge-transfer sensitizer. The electron transport from TiO2 to the C60 derivatives results in the generation of the cathodic photocurrent. The short-circuit photocurrent of a C60 tetracarboxylic acid is 0.45 μA/cm2 under 464 um light illumination. The photoelectric behaviour of ITO electrodes modified by the same C60 carboxylic acids is different from that of the modified TiO2 electrodes, and shows anodic photocurrent.
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摘要 :
Nano-sized Ni particles on TiO2-SiO2 were synthesized by the two methods of photo-assisted deposition(PAD) and impregnation.H2,which is a promising energy carrier,with a low CO concentration was produced by the photocatalytic refo...
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Nano-sized Ni particles on TiO2-SiO2 were synthesized by the two methods of photo-assisted deposition(PAD) and impregnation.H2,which is a promising energy carrier,with a low CO concentration was produced by the photocatalytic reforming of glucose(a model biomass) on the Ni/TiO2-SiO2 catalyst.The supported Ni enhanced the rate of H2 production while it suppressed CO selectivity.The catalysts were characterized by X-ray diffraction,X-ray absorption fine structure,transmission electron microscope,and nitrogen adsorption analysis.Both H2 production and CO selectivity were strongly dependent on the preparation method,and PAD-Ni/TiO2-SiO2 was the better catalyst for H2 production with the lowest CO concentration.
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