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排序方式: 共有1178条查询结果,搜索用时 15 毫秒
991.
992.
Rina Fujiwara-Tani Ayaka Okamoto Hiroyuki Katsuragawa Hitoshi Ohmori Kiyomu Fujii Shiori Mori Shingo Kishi Takamitsu Sasaki Chie Nakashima Isao Kawahara Yudai Hojo Yukiko Nishiguchi Takuya Mori Takeshi Mizumoto Kenta Nagai Yi Luo Hiroki Kuniyasu 《International journal of molecular sciences》2021,22(23)
993.
Macrolayer thicknesses in transition boiling were determined from the energy balance relation qtr = ρlHfgδl·f , based on measurements of qtr (the time-averaged heat flux in transition boiling) and f (the detachment frequency of vapor masses) for water and ethanol boiling on vertical and horizontal 15-mm-diameter surfaces under atmospheric pressure. The macrolayer thickness for the vertical surface, designed to prevent liquid contact with the periphery of the surface during the vapor mass hovering, agreed well with the correlation proposed previously by the present authors, when the heat flux at macrolayer formation is obtained from a nucleate boiling curve extrapolated to the superheat of transition boiling. The macrolayer on the horizontal surface was apparently thickened due to the inflow of bulk liquid beneath the growing vapor masses. © 1999 Scripta Technica, Heat Trans Jpn Res, 27(8): 568–583, 1998 相似文献
994.
995.
Plasma polymerization of trimethylsilane (TMS) in cascade arc discharge was experimentally investigated. It was found that the deposition rates of methane and TMS plasma polymer were dependent on plasma parameters, and the surface characteristics of plasma polymer were also dependent on plasma variables. The following plasma variables were studied: arc current, argon flow rate, TMS flow rate, chamber pressure, substrate axial, and radial positions. Carbon, silicon, and oxygen were the main elements observed in TMS polymer films obtained by x-ray photoelectron spectroscopy (XPS). Powder-like TMS polymer films were observed by scanning electron microscopy (SEM). The size distribution of the powder-like particles was strongly dependent on deposition parameters. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 1653–1665, 1997 相似文献
996.
Randomly and preferentially oriented thin films of yttria stabilized zirconia (YSZ) have been prepared on fused quartz substrates by ultrasonic spray pyrolysis using zirconium octylate and yttrium octylate as metallo-organic precursors at a substrate temperature of 873–1023 K. The as-deposited films composed of fine columnar grains were found to be crystalline and transparent with a cubic fluorite structure. With increasing substrate temperature the growth rate and diameter of the columnar grains increased and the crystal habit showed a preferential orientation at the (111) plane. 相似文献
997.
M Yabuki S Kariya R Ishisaka T Yasuda T Yoshioka AA Horton K Utsumi 《Canadian Metallurgical Quarterly》1999,26(3-4):325-332
Nitric oxide (NO) released from (Z)-1-[N-(2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1- ium-1,2-diolate (DETA/NO or NOC-18) induces apoptosis in human leukemia HL-60 cells. In this study, we isolated a HL-60 variant cell line, HL-NR6, that is resistant to DETA/NO toxicity as assessed by DNA fragmentation, morphology, and colony forming ability. The variant cells also showed resistance to reactive oxygen species (ROS) such as superoxide and hydrogen peroxide as well as NO donors, but not to anti-tumor drugs. We found that HL-NR6 cells when compared with HL-60 cells possessed twice the activities of Cu,Zn-superoxide dismutase (Cu,Zn-SOD) and catalase, but no change in Mn-SOD nor in glutathione peroxidase. Immunoblotting confirmed the high levels of both enzymes in the variant cell. We also observed that ROS generation following DETA/NO exposure was substantially higher in HL-60 cells than in HL-NR6 cells, using the 2',7'-dichlorofluorescein fluorometric method. Moreover, the SOD mimetic Mn(III) tetrakis(1-methyl-4-pyridyl) porphyrin and exogenous catalase effectively attenuated DETA/NO-elicited DNA fragmentation in HL-60 cells. Taken together, these data suggested that the NO resistance in HL-NR6 cells is associated with the increased Cu,Zn-SOD/catalase and that NO-mediated apoptosis in HL-60 cells is correlated with the generation of ROS and derived molecules like peroxynitrite. 相似文献
998.
The effects of the liquid–coating interface and coating–metal interfaces on corrosion protection of a coated aluminum sheet (Alclad 7075-T6) were investigated using electrochemical impedance spectroscopy (EIS) of selected model systems. Parylene C was deposited on a solvent-cleaned aluminum sheet to prepare the coated aluminum sheet. Parylene C does not adhere well to most smooth surfaces: a freestanding film can easily be peeled off the substrate, although it does not peel off by itself during EIS measurements. When an ultra-thin layer of plasma polymer (ca. 50 nm) is deposited on the substrate, however, Parylene C adheres very strongly to the sheet. The top surface of Parylene C coating was modified via deposition of an ultra-thin layer of either a very hydrophobic or a very hydrophilic plasma polymer. The EIS Bode plot for the first run showed a typical good barrier coating regardless of the nature of the two interfaces under consideration. However, it was found that the impedance value in the lower frequency region decreases with increased immersion time, and the time-dependent change is greatly influenced by the nature of the two interfaces. A hydrophilic top surface increased the rate of time-dependent change, while good adhesion of Parylene C to the metal decreased the extent of time-dependent change. With a hydrophobic top surface and good adhesion to the substrate, EIS characteristics of a Parylene C coated sheet remained unaffected for 18 days (the longest time employed in this study). The decrease in impedance in the low frequency region converges to the Bode plot for a freestanding Parylene C film. The early decline of EIS characteristics can be correlated to the (pre-corrosion) micro-delamination of the coating. 相似文献
999.
1000.
Sara Yoshio Junichi Tatami Tomohiro Yamakawa Toru Wakihara Katsutoshi Komeya Takeshi Meguro Kenji Aramaki Kouichi Yasuda 《Carbon》2011,(13):4131-4137
Carbon nanotubes (CNTs) were dispersed in ethanol by bead milling to form a CNT suspension. The size and shape of the CNTs were not changed after bead milling. The Brownian motion of the CNTs was observed by an optical microscope. It was shown by analysis off the trajectory of individual CNTs that the diffusion coefficient of their translational Brownian motion was 4.5 × 10−13 m2 s−1. The ratio of the particle mobilities due to drift flow and diffusion flow was 2.4, which is almost the same as for a high-molecular-weight protein. Shear thinning occurred in the CNT suspension, which means that the CNTs were oriented in the suspension under a high shear rate at low viscosity. The intrinsic viscosity for shear rates of 0 and ∞ agreed with those calculated using Simha’s equation and Leal and Hinch’s equation, respectively. Based on the experimental results, the CNTs were found to be well dispersed as isolated and nanosized rod-like particles in the suspension. CNT-dispersed Si3N4 ceramics were fabricated using the CNT suspensions. As a result, the bead milling improved the bend strength of the CNT Si3N4 ceramics compared with the wet ball milling because granules of CNTs were eliminated by the bead milling. 相似文献