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81.
Low-resistivity indium tin oxide [ITO] film was successfully deposited on oxygen plasma-treated polyethylene terephthalate [PET] surfaces at room temperature. X-ray diffraction [XRD] measurements demonstrated that the film deposited on the PET surface that had not been treated with oxygen plasma had an amorphous structure. In contrast, after the low-power oxygen plasma treatment of the PET surface, the ITO film deposited on the PET surface had a poly-crystalline structure due to interactions between electric dipoles on the PET surface and electric dipoles in the ITO film. The minimum resistivity of the poly-crystalline ITO was about 3.6 times lower than that of the amorphous ITO film. In addition, we found that the resistivity of ITO film is proportional to the intensity of the (400) line in the film's XRD spectra. 相似文献
82.
Giuseppe Pezzotti Hans-Joachim Kleebe Kazuhiro Okamoto Ken'ichi Ota 《Journal of the American Ceramic Society》2000,83(10):2549-2555
Three high-purity SiAlON materials (Si6− z Al z O z N8− z , z = 1, 2, 3) were characterized with respect to both structure and viscous behavior of internal grain boundaries. Internal friction experiments provided a direct measure of the intrinsic viscosity of grain boundaries and concurrently revealed the occurrence of a grain-boundary interlocking mechanism that suppressed sliding. A residual glass phase (consisting of aluminum-rich SiO2 ) and nanometer-sized mullite residues were found at glassy triple-grain junctions of the z = 1 SiAlON. A low-melting intergranular phase dominated the high-temperature behavior of this material and caused grain-boundary sliding at temperatures as low as 1100°C. A quantitative analysis of the grain-boundary internal friction peak as a function of oscillation frequency indicated an intergranular film viscosity of log η∼ 7.5 Pa · s at 1100°C. Glass-free grain boundaries were a characteristic of SiAlON materials with z ≥ 2, which yielded a significant improvement in refractoriness as compared to the z = 1 SiAlON material. In these materials, relaxation resulting from grain-boundary sliding was suppressed, and the internal friction curve simply experienced an exponential-like increase. 相似文献
83.
Yoshikazu Suzuki Héctor A. Calderón Naoki Kondo Tatsuki Ohji 《Journal of the American Ceramic Society》2000,83(6):1346-1350
The in situ formation of magnetoplumbite-type (M-type) hexaferrites within a 3Y-TZP matrix was examined for the La2 O3 –ZnO–Fe2 O3 and BaO–Fe2 O3 systems. The formation of barium hexaferrite (Ba-M) was rapid enough at a temperature of 1300°C for 2 h to result in a uniform dispersion of fine Ba-M particles in a tetragonal zirconia polycrystal (TZP) matrix. However, the formation of lanthanum-substituted hexaferrite (La-M) was rather sluggish, despite the existence of a charge-compensating divalent oxide. The 3Y-TZP/20-wt%-BaFe12 O19 in situ composite possessed good magnetic properties, as well as moderately good mechanical properties. 相似文献
84.
Porous Titania Ceramic Prepared by Mimicking Silicified Wood 总被引:6,自引:0,他引:6
Toshitaka Ota Masaki Imaeda Haruyuki Takase Mikihiro Kobayashi Noboru Kinoshita Tunehisa Hirashita Hidetoshi Miyazaki Yasuo Hikichi 《Journal of the American Ceramic Society》2000,83(6):1521-1523
A porous titania ceramic with a woodlike microstructure that was analogous to silicified wood was prepared. The production of "titanified wood" was performed using the following process: (i) introduction of titanium tetraisopropoxide into wood materials via vacuum infiltration, (ii) hydrolysis of the titanium tetraisopropoxide in the cell structure to form a titania gel, and (iii) firing at a temperature of 600°–1400°C in air. The resulting titania ceramic had the same external and internal forms of the original wood. 相似文献
85.
Minako Nagamori Taro Shimonosono Soichiro Sameshima Yoshihiro Hirata Naoki Matsunaga Yoshio Sakka 《Journal of the American Ceramic Society》2009,92(S1):S117-S121
A thin film (60 μm thick) of a gadolinium-doped ceria (GDC) electrolyte was prepared by the doctor blade method. This film was laminated with freeze-dried 42 vol% NiO–58 vol% GDC mixed powder and pressed uniaxially or isostatically under a pressure of 294 MPa. This laminate was cosintered at 1100 °–1500 °C in air for 4–12 h. The laminate warped because of the difference in the shrinkage of the electrolyte and electrode during the sintering. A higher shrinkage was measured for the electrode at 1100 °–1200 °C and for the electrolyte at 1300 °–1500 °C. The increase of the thickness of anode was effective in decreasing the warp and in increasing the density of the laminated composite. The maximum electric power density with a SrRuO3 cathode using 3 vol% H2 O-containing H2 fuel was 100 mW/cm2 at 600 °C and 380 mW/cm2 at 800 °C, respectively, for the anode-supported GDC electrolyte with 30 μm thickness. 相似文献
86.
Tomoko Uchiyama Hiroyo Ota Chiho Ohbayashi Shin Takasawa 《International journal of molecular sciences》2021,22(23)
Sleep apnea syndrome (SAS) is a prevalent disorder characterized by recurrent apnea or hypoxia episodes leading to intermittent hypoxia (IH) and arousals during sleep. Currently, the relationship between SAS and metabolic diseases is being actively analyzed, and SAS is considered to be an independent risk factor for the development and progression of insulin resistance/type 2 diabetes (T2DM). Accumulating evidence suggests that the short cycles of decreased oxygen saturation and rapid reoxygenation, a typical feature of SAS, contribute to the development of glucose intolerance and insulin resistance. In addition to IH, several pathological conditions may also contribute to insulin resistance, including sympathetic nervous system hyperactivity, oxidative stress, vascular endothelial dysfunction, and the activation of inflammatory cytokines. However, the detailed mechanism by which IH induces insulin resistance in SAS patients has not been fully revealed. We have previously reported that IH stress may exacerbate insulin resistance/T2DM, especially in hepatocytes, adipocytes, and skeletal muscle cells, by causing abnormal cytokine expression/secretion from each cell. Adipose tissues, skeletal muscle, and the liver are the main endocrine organs producing hepatokines, adipokines, and myokines, respectively. In this review, we focus on the effect of IH on hepatokine, adipokine, and myokine expression. 相似文献
87.
In Situ Measurement of Bridging Stresses in Toughened Silicon Nitride Using Raman Microprobe Spectroscopy 总被引:1,自引:0,他引:1
Giuseppe Pezzotti Naoki Muraki Naoki Maeda Kouji Satou Toshihiko Nishida 《Journal of the American Ceramic Society》1999,82(5):1249-1256
Bridging stresses that result both from elastic tractions and frictional interlocking in the wake of an advancing crack have been evaluated quantitatively via in situ Raman microprobe spectroscopy in a toughened Si3 N4 polycrystal. Crack opening displacement (COD) profiles of bridged cracks also have been measured quantitatively via scanning electron microscopy to substantiate the piezospectroscopic determination of microscopic stresses via Raman spectroscopy. The highest spatial resolution of the stress measurement in the Raman apparatus was 1 µm, as dictated by the optical lens that was used to focus the laser on the sample. Measurements of the bridging stresses were performed both at fixed sites (as a function of the applied load) and along the profile behind the crack tip (under a constant load). Rather high stress values (i.e., 0.4-1.1 GPa) were measured that corresponded with unbroken ligaments that bridged the crack faces in elastic fashion, whereas frictional sites were typically under a lower tensile stress (0.1-0.5 GPa). Mapping the near-tip COD profile and the bridging stresses at the (normal) critical load for catastrophic fracture enabled us to calculate the crack-tip toughness and to explain the rising R -curve behavior of the material. From a comparison with conventional fracture-mechanics data, a self-consistent view of the mechanics that govern the toughening behavior of the Si3 N4 polycrystal could be obtained. In particular, crack bridging is proven to be, by far, the most important mechanism that contributes to the toughening of polycrystalline Si3 N4 materials. 相似文献
88.
A new electrochemical heat pump using a combination of an electrolytic reaction at lower temperature to absorb low grade thermal energy and a thermochemical reaction at higher temperature to produce more efficient thermal energy is proposed. At a lower temperature, an endothermic reaction which cannot occur thermochemically proceeds with electrolysis. At a higher temperature, an exothermic reaction which is the reverse of the electrolysis reaction occurs thermochemically to produce high grade thermal energy. The water gas shift reaction, CO2(g) + H2(g) CO(g) + H2O(g), in molten carbonate is one possible candidate for the new electrochemical heat pump and can lead to an increase in the temperature of the thermal energy from 1100 to 1200K. A heat pump system using the shift reaction is also considered theoretically. 相似文献
89.
Polystyrene–clay hybrids (PSCHs) were prepared by melt blending a styrene vinyloxazoline copolymer with organophilic clay. In the PSCHs, the silicate layers of the clay were delaminated and dispersed homogeneously to the nanometer level. The moduli of the PSCHs were higher than that of the PS copolymer. For example, the tensile modulus of the PSCH with 5 wt % clay was 1.4 times higher compared to that of the PS copolymer. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 3359–3364, 1999 相似文献
90.
Naoki Dohi Yukimasa Matsuda Norihiro Itano Kazuhiro Shimizu Kimio Mineka Wa Yoshinorika Wase 《加拿大化工杂志》1999,77(5):786-792
Mixing in a boil-off mechanically stirred tank reactor with multiple impellers was examined. Power consumption and gas hold-up were measured in boiling water in a 0.2 m i.d. stirred tank reactor with three four-pitched blade downflow disk turbines. Vapour was generated from both the immersed ring heater and the impellers. At low vapour generation rates, vapour was mainly generated from the impellers rather than from the heater, whereas nucleation occurred at the heater instead of the impeller at higher vapour generation rates. The mechanical power consumption decreased due to vapour generation. The change in boiling-to-non-boiling mechanical power ratio with varying impeller rotational speed and boiling rate was complicated and not monotonous except at higher impeller speeds and boiling rates. The gas hold-ups increased with increasing vapour generation rate but were rather small as compared to those in cold gas dispersing systems. Empirical correlations for power consumption and gas hold-up in boiling liquids were developed using the present experimental data. 相似文献