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Thin film deposition processes emit large amounts of NF3 and by-product particles, which are of great concerns in the semiconductor industry, from the environmental and economic points of view. With an objective to overcome these concerns, plasmas are generated from a cylindrical reactor placed before a vacuum pump. The discharge stability is evaluated by monitoring the changes in the plasma images with the pressure. By using a particle sampler and a particle trap, the size and quantity of the by-product particles are compared during plasma-on and plasma-off. The effects of adding O2 and H2O to the by-products of the NF3 abatement process are investigated by analyzing the spectra obtained with a Fourier transform infrared spectroscopy. Further, the H2O flow rate is optimized for the highest destruction and removal efficiency of NF3. Finally, the applicability of our device to the after-treatment equipment is discussed. 相似文献
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In this note, we construct generalized Shioda-Inose structures on K3 surfaces using cyclic covers and almost functoriality of Shioda-Inose structures with respect to normal subgroups of a given group of symplectic automorphisms. 相似文献
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A Highly Stable and Magnetically Recyclable Nanocatalyst System: Mesoporous Silica Spheres Embedded with FeCo/Graphitic Shell Magnetic Nanoparticles and Pt Nanocatalysts
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Da Jeong Kim Dr. Yan Li Yun Jin Kim Prof. Nam Hwi Hur Prof. Won Seok Seo 《化学:亚洲杂志》2015,10(12):2755-2761
We have developed a highly stable and magnetically recyclable nanocatalyst system for alkene hydrogenation. The materials are composed of mesoporous silica spheres (MSS) embedded with FeCo/graphitic shell (FeCo/GC) magnetic nanoparticles and Pt nanocatalysts (Pt‐FeCo/GC@MSS). The Pt‐FeCo/GC@MSS have superparamagnetism at room temperature and show type IV isotherm typical for mesoporous silica, thereby ensuring a large enough inner space (surface area of 235.3 m2 g?1, pore volume of 0.165 cm3 g?1, and pore diameter of 2.8 nm) to undergo catalytic reactions. We have shown that the Pt‐FeCo/GC@MSS system readily converts cyclohexene into cyclohexane, which is the only product isolated and Pt‐FeCo/GC@MSS can be seperated very quickly by an external magnetic field after the catalytic reaction is finished. We have demonstrated that the recycled Pt‐FeCo/GC@MSS can be reused further for the same hydrogenation reaction at least four times without loss in the initial catalytic activity. 相似文献
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The crystal structures and the magnetic properties of three new binary rare-earth intermetallic phases are reported. alpha-Sm3Ge5 and beta-Sm3Ge5 and Gd3Ge5 have been prepared from the corresponding elements through high-temperature reactions using the flux-growth method. The structures of the three compounds have been established using single-crystal X-ray diffraction: alpha-Sm3Ge5 crystallizes with its own type in the hexagonal space group P2c (No. 190) with cell parameters a = 6.9238(11) A, c = 8.491(3) A, and Z = 2, whereas beta-Sm3Ge5 adopts the face-centered orthorhombic Y3Ge5 type with space group Fdd2 (No. 43) and with cell parameters a = 5.8281(6) A, b = 17.476(2) A, c = 13.785(2) A, and Z = 8. The orthorhombic Gd3Ge5 with cell parameters a = 5.784(2) A, b = 17.355(6) A, and c = 13.785(5) A is isostructural with beta-Sm3Ge5. The structures of the title compounds can be described as AlB(2) and alpha-ThSi2 derivatives with long-range ordering of the germanium vacancies. Temperature-dependent DC magnetization (5-300 K) measurements show evidence of antiferromagnetic ordering below ca. 30 and 10 K for alpha-Sm3Ge5 and beta-Sm3Ge5, respectively. Gd3Ge5 undergoes two successive magnetic transitions below ca. 15 and 11 K. The temperature dependence of the resistivity and heat capacity of Gd3Ge5 are discussed as well. 相似文献
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Hur SG Kim TW Hwang SJ Hwang SH Yang JH Choy JH 《The journal of physical chemistry. B》2006,110(4):1599-1604
We have synthesized heterostructured zinc oxide-aluminosilicate nanohybrids through a hydrothermal reaction between the colloidal suspension of exfoliated montmorillonite nanosheets and the sol solution of zinc acetate. According to X-ray diffraction, N2 adsorption-desorption isotherm, and field emission-scanning electron microscopic analyses, it was found that the intercalation of zinc oxide nanoparticles expands the basal spacing of the host montmorillonite clay, and the crystallites of the nanohybrids are assembled to form a house-of-cards structure. From UV-vis spectroscopic investigation, it becomes certain that calcined nanohybrid contains two kinds of the zinc oxide species in the interlayer space of host lattice and in mesopores formed by the house-of-cards type stacking of the crystallites. Zn K-edge X-ray absorption near-edge structure/extended X-ray absorption fine structure analyses clearly demonstrate that guest species in the nanohybrids exist as nanocrystalline zinc oxides with wurzite-type structure. 相似文献
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Kim WK Sul OJ Kwak JS Hur HY Latour AM Koller BH Kwon BS Jeong CS 《Experimental & molecular medicine》2010,42(12):805-810
Tumor necrosis factor receptor-related 2 (TR2, HVEM or TNFRSF-14) plays an important role in immune responses, however, the mechanisms regulating its expression are unclear. To understand the control of TR2 gene expression, we studied the upstream region of the gene. Gel supershift assays revealed inducible binding of nuclear factor of activated T cells (NFAT) to a putative NFAT site within the TR2 promoter. Furthermore, cotransfection of a dominant negative NFAT construct, or siRNA for NFAT, resulted in increased expression of a TR2 reporter gene. Our findings demonstrate that NFAT negatively regulates TR2 expression in activated T cells. 相似文献
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