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101.
Chie Ando Toshimasa Suzuki Youichi Mizuno Hiroshi Kishi Sayuri Nakayama Mamoru Senna 《Journal of Materials Science》2008,43(18):6182-6192
In an attempt to obtain finest possible microparticles of BaTiO3 (BT) with highest possible tetragonality via a solid state route, starting mixtures comprising BaCO3 and TiO2 were subjected to various pretreatments including addition of glycine and mechanical activation. Reaction processes were
monitored by the changes in the weight, crystallinity, and morphology in detail. While mechanical activation with glycine
significantly increased the rate of reaction and homogeneity of the particle size of the product, BT, simultaneous particle
growth of BT was intolerably acute for micro-electronic devices. The fast particle coarsening was predominated by the coalescence
of BT tiny particles formed around titania. A mixture with higher homogeneity was attained by using finer starting materials
under wet mixing, avoiding significant mechanical stressing. Particle growth of BT was suppressed to ca. 100 nm to obtain
fully crystallized BT particles without significant loss of tetragonality and, hence, close to meet our requirements for MLCCs. 相似文献
102.
Some tetracycline (TC) antibiotics, including TC and anhydrotetracycline, have been found to enhance specific binding of low
density lipoprotein (LDL) to both LDL receptor-positive and-negative cells at relatively higher concentrations. When incubated
at 37°C, the ability of LDL receptor-negative human fibroblasts to bind 125I-LDL was increased from<2 to 45 ng/mg by 170 μM TC. In normal human fibroblasts and Hep G2 cells, 125I-LDL binding was elevated 1.4- to 2-fold by 113 μM TC. The 125I-LDL binding in the presence of TC was diminished by both heparin and EDTA. The enhancement by TC was not observed when 125I-LDL binding was assayed at 4°C. TC enhanced LDL binding to paraformaldehyde-fixed Hep G2 cells, excluding LDL receptor induction
in the mechanism. These results demonstrated that TC enhanced cellular LDL binding through a process not involving functional
LDL receptors. 相似文献
103.
104.
Conditions for synthesizing acicular fine particles of goethite with high aspect ratio were devised by oxidizing mixed slurry
comprising ferrous carbonate and hydroxide after neutralizing by alkali carbonate. By bubbling N2 after neutralization into the slurry containing FeCO3 and Fe(OH)2, dissolved CO2 is ejected. As a consequence, the relative concentration of CO32− decreases and that of hydroxide increases. These favor the increase of the aspect ratio of the goethite particles via two
factors, i.e., (1) decrease in the critical size of the nuclei and (2) suppression of growth inhibition at the tip of needle-like
particles due to CO32− adsorption. We propose a reaction scheme for the entire processing. 相似文献
105.
Preloading clayey deposit by vacuum pressure with cap-drain: Analyses versus performance 总被引:4,自引:0,他引:4
A method of improving soft clayey deposit by combining cap-drain (CPVD) with vacuum pressure is described. The method uses a surface or subsurface soil layer as a sealing layer with no need to place an air-tightening sheet on the ground surface. It is explained that the method has advantages for the following situations: (a) a higher air/water permeability layer at ground surface and (b) combining vacuum pressure with embankment load. A case history of consolidating a reclaimed clayey deposit by combining CPVD with vacuum pressure is analyzed and discussed. The site was in an under-consolidated state before starting the project. It is shown that the method is effective, and the method proposed by Chai et al. [Ground deformation induced by vacuum consolidation. Journal of Geotechnical and Geoenvironmental Engineering, ASCE 131(12), 1552–1561] for calculating the vacuum-pressure-induced ground deformation is useful for the design of the vacuum consolidation project. The back-calculation shows that for this under-consolidated deposit, vacuum pressure caused plane strain type isotropic deformation near the ground surface. 相似文献
106.
Kuwatsuka H. Mikawa T. Miura S. Yasuoka N. Tanahashi T. Wada O. 《Photonics Technology Letters, IEEE》1990,2(1):54-55
An AlxGa1-xSb avalanche photodiode (APD) with an Al composition of 0.05 has been fabricated and tested. The measured gain-bandwidth (GB) product of the highly doped diode is 90 GHz. Such a large GB product has never been previously achieved by any APD materials sensitive in the long-wavelength region. This suggests the advantage of the AlxGa1-xSb material system for very high-speed operation 相似文献
107.
Suzuki E. Miura K. Hayasi Y. Tsay R.-P. Schroder D.K. 《Electron Devices, IEEE Transactions on》1989,36(6):1145-1149
The carrier transport properties in metal-oxide (top oxide) nitride-oxide (tunnel oxide) silicon (MONOS) memory structures have been investigated in steady-state conditions under negative gate bias voltage. Carriers were separated into holes and electrons utilizing an induced junction of the p-channel MONOS transistors. Two-carrier transport is confirmed in the structure at negative gate polarity. It is found that the relatively thick top oxide acts as a potential barrier to the holes injected from the Si into the thin nitride. It is also found that a portion of the electrons injected from the gate at negative gate polarity recombine with the holes injected from the Si even in such a thin nitride and/or at the top-oxide/nitride interface 相似文献
108.
J. Enrique Juli Yang Liu Sidharth Paranjape Mamoru Ishii 《Nuclear Engineering and Design》2008,238(1):156-169
Traditionally, the flow regimes in two-phase flow are considered in a global sense. However, a local flow regime is required to understand and model the interfacial structures present in the flow. In this work, a new approach has been used to identify both global and local flow regimes in a two-phase upward flow in a 50.8 mm internal diameter pipe under adiabatic conditions. In the present method, the bubble chord length distributions, which are measured simultaneously with three double-sensor conductivity probes, have been used to feed a self-organized neural network. The global flow regime identification results show a reasonable agreement with the visual observation for all the flow conditions. Nonetheless, only the local flow regimes measured at the center of the pipe agree with the global ones. The local flow regime combinations found are analyzed using the flow map information, cross-correlations between the probe signals, and previous correlations. In this way, it is possible to identify eight different global flow regime configurations. 相似文献
109.
1,3-Dipalmitoyl-2-oleoyl-sn-glycerol (POP) and 1,2-dioleoyl-3-palmitoyl-rac-glycerol (OOP) are two major molecular species that account for roughly half of the total triacylglycerols in palm oil. The
binary phase behavior of a POP/OOP mixture plays an important role in the crystallization of palm oil. We conducted thermodynamic
and kinetic studies of OOP and its mixtures with POP using differential scanning calorimetry and X-ray diffraction with a
conventional generator and synchrotron radiation. We found that OOP has two polymorphs, α as a metastable form and β′ as the
most stable form, and that the two forms are stacked in a triple-chain-length structure. The POP/OOP mixtures exhibited immiscible
eutectic natures in both their metastable and their most stable states, in contrast to POP/1,2-dipalmitoyl-3-oleoyl-rac-glycerol and POP/1,3-dioleoyl-2-palmitoyl-sn-glycerol mixtures, in which molecular compounds of a double-chain-length structure were formed. A time-resolved synchrotron
radiation X-ray diffraction study undertaken during the cooling and heating processes indicated that the α and β′ forms of
the POP and OOP fractions crystallized and melted in separate manners, and that crystallization of the β′ form and the polymorphic
transformation from α to β′ of POP and OOP are promoted in the presence of another component. The absence of molecular compound
crystals in the binary mixtures of POP/OOP is explained by taking into account the molecular interactions of acyl chain packing,
glycerol conformation, and methyl end stacking, among which glycerol conformation appeared to be most influential. 相似文献
110.
Hiroyuki Yoshida Takeshi Kataoka Mamoru Nango Shozo Ohta Nobuhiko Kuroki Masako Maekawa 《应用聚合物科学杂志》1986,32(3):4185-4196
The dyeing process for a cellulose membrane–direct dye system is analyzed based on a parallel transport mechanism of surface and pore diffusion with Freundlich isotherm. Numerical solutions were obtained in order to clarify how the surface and pore diffusion resistances affect the uptake curve. The numerical solutions were also compared with an analytical solution for surface diffusion control to establish the range where the analytical solution can be considered as an acceptable approximation. The uptake curves in the cellulose membrane-chromophore (C.I. Direct Yellow 12) system in the presence of inorganic electrolyte were measured. The rate of adsorption and the maximum amount of adsorption increased with an increase in the concentration of those electrolytes. The rate of adsorption was approximately controlled by the surface diffusion rather than by pore diffusion. The surface diffusivities of the dye were little affected by either the concentration and or nature of the electrolyte. 相似文献