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排序方式: 共有1332条查询结果,搜索用时 15 毫秒
1.
Xianwei Su Xiaojia Shang Yusi Che Shaolong Li Jianxun Song Jilin He 《Ceramics International》2021,47(15):21459-21465
Homogenous ZrCxOy powders have been successfully synthesized by in-situ electro-reduction of solid ZrO2–C composite precursors in molten CaCl2. The effect of applied cell voltage and molar ratio of ZrO2 to C on preparation of ZrCxOy were investigated. The reduction pathway of the composite electrode was studied based on the analysis of intermediate products using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that ZrO2 is firstly converted to CaZrO3. The resulting CaZrO3 is then reduced to ZrCxOy. The ZrCxOy formation is dramatically influenced by electrolysis voltage and molar ratio of ZrO2 to C: a higher cell voltage and lower molar ratio of the ZrO2 to C are more preferable for the formation of ZrCxOy powder. Homogenous ZrCxOy powders with particle size of ~100 nm are synthesized by ZrO2/C starting elemental powders in CaCl2 molten salt at 1123 K for more than 3 h, when the cell voltage is 3.0 V and the molar ratio of the ZrO2 to carbon starting materials is 1:1.0. 相似文献
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Jialiang Pan Ziying Guo Zhenpeng Zhu Zishan Sun Tingting Zhang Jilin Zhang Xinguo Zhang 《Ceramics International》2018,44(17):20732-20738
High-efficient Ce3+/Tb3+ co-doped Ba3Y2B6O15 phosphors with multi color-emitting were firstly prepared, and their structural and luminescent properties were studied by XRD Rietveld refinement, emission/excitation spectra, fluorescence lifetimes as well as temperature-variable emission spectra. Upon 365?nm excitation, the characteristic blue Ce3+ band along with green Tb3+ peaks were simultaneously found in the emission spectra. Moreover, by increasing concentration of Tb3+, a blue-to-green tunable emitting color could be realized by effective Ce3+→Tb3+ energy transfer. Furthermore, all Ba3Y2B6O15: Ce3+, Tb3+ phosphors exhibit high internal quantum efficiency of ~?90%, while the temperature-variable emission spectra reveal that the phosphors possess impressive color stability as well as good thermal stability (T50 =?~?120?°C). The results indicate that these efficient color-tuning Ba3Y2B6O15: Ce3+, Tb3+ might be candidate as converted phosphor for UV-excited light-emitting diodes. 相似文献
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The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless person- 相似文献
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Jilin Zhang 《Journal of Adhesion Science and Technology》2014,28(8-9):751-768
Superhydrophilic surfaces have recently received some attention due, in large part to the intense interest on the antonymous field of superhydrophobicity. Imparting superhydrophilicity onto surfaces through coatings, texturing, or choice of materials appears to hold significant commercial promise for the protection for optical devices (e.g. anti-fogging), self-cleaning, and stain resistant paints and flooring and use in the area of ‘intelligent’ coatings. In this review, the fabrication and application of artificial superhydrophilic surfaces are discussed. The focus is on results reported over the past decade for these materials. The contents of this review are written to provide an introductory yet comprehensive overview of this emerging field. 相似文献
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通过实验研究颗粒在不同椭圆滚筒内的运动情况,分析了不同填充率、不同转速和不同颗粒粒径对其的影响。由实验得出:颗粒在椭圆不同位置的运动情况并不一致,随着长短轴之比变大,运动趋于平缓;填充率降低会引起颗粒运动模式过渡区间变大,进入小瀑布模式所需转速增加;颗粒粒径增大,颗粒在筒内受重力、摩擦力的影响变得更加明显,在长轴垂直水平位置,所受惯性影响更加显著,并出现明显的多种模式相结合的运动形式。 相似文献
8.
Yani He Jilin Zhang Wenli Zhou Jin Han Zhongxian Qiu Liping Yu Chunying Rong Shixun Lian 《Journal of the American Ceramic Society》2014,97(5):1517-1522
A single‐phase multicolor emitting phosphor, Ca3Al2O6:Ce3+,Li+, was prepared by a solid‐state reaction. When the Ce3+ concentration is lower than 0.030 (molar ratio in Ca3Al2O6), yellow and greenish blue emissions can be observed under the excitation by a blue and a near UV light, respectively. The yellow‐emitting phosphor possesses an internal quantum efficiency of 89%. Additional purplish blue emission turns up when Ce3+ concentrations are higher than 0.040. Tunable emission bands are originated from Ce3+ ions on different Ca sites in Ca3Al2O6. Although the emission band of purplish blue or greenish blue overlaps the excitation band of yellow emission, and the distances between the unlike Ce3+ ions are in the range of electric dipole–dipole interaction, no energy transfer is observed. Furthermore, emission wavelengths for the yellow, greenish blue, and purplish blue emission show little change upon increasing Ce3+ concentrations. 相似文献
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通过断口(宏观)形貌分析、微观组织分析、化学成分检测以及硬度测试等手段对SCM435钢发动机缸盖螺栓的疲劳断裂进行失效分析。结果表明,失效SCM435钢缸盖螺栓的化学成分和显微组织合格,硬度符合技术要求。失效样件1的断裂原因为表面脱碳引起的脆性断裂,螺栓断裂部位的表面脱碳层宽为120μm;失效样件2主要是非金属夹杂物所引起的疲劳断裂,近球状的CaS-CaO-Al2O3-MgO复合型冶金夹杂物造成了沿晶裂纹。对材料的塑韧性、表面脱碳及非金属夹杂物等指标,提出了改善建议。 相似文献