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排序方式: 共有2378条查询结果,搜索用时 15 毫秒
1.
《Ceramics International》2022,48(12):16808-16812
Flash sintering has been reported in various ceramics. Nevertheless, anion and cation conductors exhibit different flash-sintering behaviors, and the interaction mechanism between the conductive species and the sintering environment has remained unclear. Herein, we report the flash-sintering phenomena of a typical cation conductor, Na3Zr2(SiO4)2(PO4) with anode region surrounded by air and NaNO3 environments. The results prove that the ionic behavior and joule heating distribution can be controlled by changing the electrode environment. Four possible scenarios describing the ion migration behavior and interaction with the environment are proposed for providing a guidance for controlling the ion interaction behavior during flash sintering. 相似文献
2.
Oxide-based near infrared (IR)-shielding coatings consisting of quarter‐wave stacks of oxygen-deficient tantalum oxide (Ta2O5?x) and silicon oxide (SiO2) multilayers and tin-doped indium oxide (In2O3) (ITO) films with the thicknesses of 200–600 nm can block the passage of IR-A (wavelength: 760–1400 nm) and IR-B (wavelength: 1400–3000 nm) radiation, respectively. In this study, the optical properties and microstructure of these oxide-based IR-shielding coatings were investigated. Transmission electron microscopy images indicated that amorphous Ta2O5?x/amorphous SiO2 multilayers were uniform and dense. ITO films were found to be highly crystalline and show carrier concentrations of up to 7.1 × 1020 cm?3, resulting in the strong IR-B optical absorption due to the plasma excitation of the free carriers. Oxide-based IR-shielding coatings with an ITO thickness of 420 nm were found to have near-IR shielding rates of >90% and an average visible light transmittance of >70%. The effects of IR on human keratinocytes were studied to evaluate the IR-induced photoaging in human skin. It was found that the downregulation of cellular proliferation and the enhancement of senescence-associated β-galactosidase activity induced by IR irradiation were significantly inhibited by oxide-based IR-shielding coatings. Thus, this study provides a facile method for the development of coatings for smart windows with high IR-shielding ability and high visible light transmittance. 相似文献
3.
《Ceramics International》2022,48(16):23504-23509
KTaO3 and KTa0.9M0.1O3-α (M = Ti, Hf, Zr) were prepared by solid state reaction at 1330 °C for 2 h and characterized by x-ray diffraction. The AC impedance technique was used to analyze the sintered solid electrolytes in 1%H2/Ar and dry air atmosphere. Among KTa0.9M0.1O3-α (M = Ti, Hf, Zr), KTa0.9Zr0.1O3-α displays the highest conductivity in 1%H2/Ar atmosphere. The carriers transport numbers of solid electrolytes were measured by concentration cell method. The results show KTa0.9Zr0.1O3-α is a pure proton conductor below 525 °C. Stability tests show that KTa0.9Zr0.1O3-α has good chemical stability against CO2 and H2O. 相似文献
4.
The slight-alkalization of generator internal cooling water (GICW) is widely used to inhibit the corrosion of hollow copper conductor and thereby ensure the safe operation of the generator. CO2 inleakage is increasingly identified as a potential security risk for GICW system. In this paper, the influence of CO2 inleakage on the slight-alkalization of GICW was theoretically discussed. Based on the equilibriums of the CO2-NaOH-H2O system, CO2 inleakage saturation was derived to quantify the amount of the dissolved CO2 in GICW. This parameter can be directly calculated with the measured conductivity and the [Na+] of GICW. The influence of CO2 inleakage on the slight-alkalization conditioning of GICW and the measurement of its water quality parameters were then analyzed. The more severe the inleakage, the narrower the water quality operation ranges of GICW, resulting in the more difficult the slight-alkalization conditioning of GICW. The temperature calibrations of the conductivity and the pH value of GICW show non-linear correlations with the amount of CO2 inleakage and the NaOH dosage. This study provides insights into the influence of CO2 inleakage on the slight-alkalization of GICW, which can serve as the theoretical basis for the actual slight-alkalization when CO2 inleakage occurs. 相似文献
5.
《Journal of the European Ceramic Society》2019,39(16):5292-5297
Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF), which exhibits a high mixed oxide ionic-electronic conduction, was used for the fabrication of an oxygen separation membrane. An asymmetric structure, which was a thin and dense BSCF membrane layer supported on a porous BSCF substrate, was fabricated by the electrophoretic deposition method (EPD). Porous BSCF supports were prepared by the uniaxial pressing method using a powder mixture with BSCF and starch as the pore-forming agent (0–50 wt.%). The sintering behaviors of the porous support and the thin layer were separately characterized by dilatometry to determine the co-fired temperature at which cracking did not occur. A crack-free and thin dense membrane layer, which had about a 15 μm thickness and >95% relative density, was obtained after optimizing the processes of EPD and sintering. The dense/porous interface was well-bonded and the oxygen permeation flux was 2.5 ml (STP) min−1 cm-2 at 850 °C. 相似文献
6.
Li Lei Limin Li Shasha Wang Gaoyang Zhao Yoshifumi Oshima Yang Ren Lei Zhao Lihua Jin Yao Wang Chengshan Li Pingxiang Zhang 《Journal of the European Ceramic Society》2018,38(14):4694-4700
Highly (100)-oriented Ce1-x(Y0.2Zr0.8)xOδ (CYZO) films were prepared on biaxially textured NiW substrates by a chemical solution deposition approach using metal inorganic salts as starting materials. It has been found that both the preferential orientation and surface roughness of CYZO films decrease gradually with increasing of the doping percentage of Y3+ and Zr4+ ions. The epitaxial growth relationship of (220)CYZO//(200)NiW and [00?l]CYZO//[001]NiW was demonstrated by XRD texture measurement as well as atomic resolution STEM observation. XRD, Raman and XPS spectra results indicate that Y3+ and Zr4+ ions were indeed introduced into CeO2 lattice to substitute Ce4+ ions and form cubic fluorite CYZO solid solution. Moreover, CeO2 buffer layer can be endowed a strong enough capability to prevent element diffusion through co-doping of yttrium and zirconium, provided that an optimal doping ratio of them is adopted. This will provide a new approach to fabricating strong-barrier single buffer layer for coated conductor. 相似文献
7.
董祥国 《机械制造与自动化》2002,(6):17-19
根据三角旋转活塞发动机运动几何原理 ,详细分析了缸体型线。缸体的实际型线是双弧外摆线的等距曲线 ,并由此导出其数学表达式。本文进一步说明了两种几何运动实现方式 ,分析了参数的几何意义 ,并给出其表达式。 相似文献
8.
Organic conductor is a kind of organic compound which has special electronic and magnetic properties. The research of the organic compounds has received considerable attention because of their potential applications in many areas. The molecular conductive units are theoretically investigated as well as their energy gap and charge distribution. The relationship of conductivity and micro-mechanism is discussed. 相似文献
9.
C. Athanassiou G. Pekridis N. Kaklidis K. Kalimeri S. Vartzoka G. Marnellos 《International Journal of Hydrogen Energy》2007
In the present work, the prospects and trends of solid electrolyte membrane reactors (SEMRs) towards hydrogen production, are discussed. Initially, an overview of the principles, the properties and the techniques related to the usage of the SEMRs, are presented. In the following, a literature survey covering earlier and recent developments of the various methods (e.g. reforming or partial oxidation or dehydrogenation of hydrocarbons, steam electrolysis) employed in the SEMRs for the production of hydrogen, is performed. Finally, the current status of this research field is analyzed and future research topics are proposed. 相似文献
10.
将空气中烧成的镍导体用于散热制冷片制作工艺中,可降低成本,提高合格率。通过实验得到的最佳值为:镍导体中4号玻璃(SiO2>30,B2O3>10,PbO<55,TiO2少许)的含量4.5%,化学镀镍时间50min,方阻47.5mΩ/□,附着力8.1N/mm2。 相似文献