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排序方式: 共有848条查询结果,搜索用时 15 毫秒
1.
Ondrej Hanzel Meinam Annebushan Singh Deepak Marla Richard Sedlák Pavol Šajgalík 《Journal of the European Ceramic Society》2019,39(8):2626-2633
SiC based composites filled with graphene nano-platelets (GNPs) or graphene oxide (GO) prepared by rapid hot-pressing exhibit sufficient electrical conductivity for their machinability by wire electro-discharge machining (WEDM). Composites microstructure anisotropy caused by graphene alignment as a consequence of rapid hot pressing was confirmed by measuring of electrical conductivity and thermal diffusivity. Electrical conductivity increased significantly with increased weight fraction of graphene in both measured directions. Highest value of 2031 S/m was obtained for composites with 15 wt. % of GNPs in parallel direction and only 1246 S/m in perpendicular direction to aligned GNPs. Thermal diffusivity is 63.3 mm2/s in parallel and only 23.3 mm2/s in perpendicular direction. The increase of the electrical conductivity has resulted in successful WEDM. The MRR was almost doubled when the filler concentration increased from 5 wt. % GNPs/GO to 15 wt. % GNPs. At the same time, the surface roughness decreased. 相似文献
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Silicon - The original version of this paper was unfortunately published with an error in the order of authors and their corresponding affiliations. The correct data is shown above. 相似文献
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Silicon - Silicon carbide piezoresistive pressure sensor is more suitable for harsh environment due to its wide bandgap, corrosion tolerance, excellent chemical inertness, high Young’s... 相似文献
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Deepak Kumar Shefali Verma Kartikey Verma Sudipta Som Vijay Kumar Hendrik C. Swart 《Ceramics International》2018,44(12):13649-13653
Herein, nanocrystals of Er3+ and Er3+, Yb3+ co-doped NaYF4 upconversion (UC) phosphor were prepared via the reverse-microemulsion method. The impact of different concentrations of Er3+ ions on the UC emission intensity after 980?nm diode laser excitation is discussed. The structure, morphology and composition of the nanophosphors were confirmed by X-ray diffraction, transmission electron microscopy, scanning electron microscopy and the results showed the presence of NaYF4 nanocrystals with hexagonal phases of NaYF4. The UC spectra revealed two emission bands including a green and a red emission band and the CIE coordinate for the samples were estimated. The present research revealed that the reverse-microemulsion approach will be suitable for the synthesis of efficient upconversion nanophosphors. 相似文献
6.
Ram Gopal Ankit Goyal Ajay Saini Meena Nagar Nikita Sharma Deepak Kumar Gupta Veena Dhayal 《Ceramics International》2018,44(16):19099-19105
Synthesis of mono-crystalline Ga2O3 Nanorods was done by sol-gel transformation of gallium(III) isopropoxide (Ga(OPri)3). XRD studies were done to determine the planes and crystal structure of synthesized nanorods that showed the synthesis of β-Ga2O3(a). TEM studies of synthesized Ga2O3 confirmed the synthesis of monocrystalline β-Ga2O3 nanorods. To study the effect of precursor chemistry and to determine role of precursor structures on the crystal structure, phase and morphology of the Ga2O3, a new modified precursor complex was synthesized. The reaction of Ga(OPri)3 with N-phenylsalicylaldimine, [C6H4(OH)CH=N(C6H5)] in 1:1?M ratio yielded [{(H5C6)N?=?CH-C6H4O}Ga(OPri)2]. The newly synthesized complex was characterized by elemental analyses, molecular weight measurement, FT-IR and NMR (1H and 13C) spectral studies. Spectral studies of the modified complex suggest the presence of bi-dentate mode of attachment of Schiff's base in the solution state. Sol-gel transformations of [{(H5C6)N?=?CH-C6H4O}Ga(OPri)2] in organic medium, yielded γ-Ga2O3(b), as found by XRD studies. TEM image of the sample (a) revealed the formation of nano-rods of oxide with average diameter of ~100?nm whereas the TEM image of sample (b) showed presence of nano-sized particles of oxide with average particle size of 10?nm. Morphological and compositional studies of synthesized samples (a) and (b) were carried out using SEM and EDX. The method provides a possibility of large scale synthesis of dissimilar shaped and pure Ga2O3 nanoparticles. 相似文献
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Hemavathi N. Sriranjani R. Arulmozhi Parvathy Meenalochani M. Deepak R. U. 《Wireless Personal Communications》2022,122(2):931-946
Wireless Personal Communications - Breast cancer is one of the rapid spreading diseases resulting in the death of younger age group of women. Unfortunately, as the detection of cancer is at later... 相似文献
10.
Influence of fine ceramic aggregates on the residual properties of concrete subjected to elevated temperature 下载免费PDF全文
Deepak Rajawat Salman Siddique Sandeep Shrivastava Sandeep Chaudhary Trilok Gupta 《火与材料》2018,42(7):834-842
The residual properties of concrete subjected to elevated temperature are of importance to assess the stability of the structure. This paper investigates the performance of concrete containing white ware ceramic sand exposed to elevated temperature. Concrete mixes containing 0%, 50%, and 100% ceramic sand were prepared. The specimen were exposed to elevated temperatures of 200°C, 500°C, and 800°C for a duration of 60 minutes. Their residual mechanical properties (compressive strength, split tensile strength), ultra sonic pulse velocity, and mass change for different cooling regimes were investigated and compared among specimen. The results showed that incorporation of ceramic sand in concrete mixes improved the resistance against elevated temperature of hardened concrete. 相似文献