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101.
Masato Tazawa Kazuki Yoshimura Kazuo Igarashi Sakae Tanemura 《Solar Energy Materials & Solar Cells》1997,48(1-4)
For full understanding of the optical properties of alumina ceramics which are used as a substrate of thin film c-Si solar cells, we carried out computer simulations of diffuse reflectance and measurements of angle-resolved reflectance. As the result of the computer simulations, we obtained a theoretical expression for the reflectance properties of alumina ceramics with flat surface. The expression can be applied for the measured reflectance of alumina ceramics with rough surface when an effect of surface condition was taken into account. 相似文献
102.
Shinsuke Kajioka Naoki Wakamiya Hiroki Satoh Kazuya Monden Masato Hayashi Susumu Matsui Masayuki Murata 《Ad hoc Networks》2011,9(5):911-927
To accommodate real-time multimedia application while satisfying application QoS requirements in a wireless ad-hoc network, we need QoS control mechanisms. In this paper, we propose a new routing mechanism to support real-time multimedia communication by efficiently utilize the limited wireless network capacity. Our mechanism considers a wireless ad-hoc network composed of nodes equipped with multiple network interfaces to each of which a different wireless channel can be assigned. By embedding information about channel usage in control messages of OLSRv2, each node obtains a view of topology and bandwidth information of the whole network. Based on the obtained information, a source node determines a logical path with the maximum available bandwidth to satisfy application QoS requirements. Through simulation experiments, we confirmed that our proposal effectively routed multimedia packets over a logical path avoiding congested links. As a result, the load on a network is well distributed and the network can accommodate more sessions than QOLSR. We also conducted practical experiments using wireless ad-hoc relay nodes with four network interfaces and verified the practicality of our proposal. 相似文献
103.
104.
Masato Tazawa Masahisa Okada Kazuki Yoshimura Shunjiro Ikezawa 《Solar Energy Materials & Solar Cells》2004,84(1-4):159
Some of the heat mirrors, which have high transmittance in the visible region and high reflectance in the infrared, consist of three thin titanium compound stacked films, TiO2/TiN/TiO2 on glass substrate. TiO2 is known to have excellent photo-catalytic properties and the top layer may be expected to work as a photo-catalyst as well as the anti-reflection coating. However, strong thickness dependence of the photo-catalytic properties has been reported and the optimum thickness of the top layer for the heat mirror was too thin for the photo-catalytic properties for decomposition of acetaldehyde gas. In this report, we show a possibility to realize a multi-functional heat mirror which shows the photo-catalytic and heat mirror effects simultaneously by optical calculation and preliminary experiments. We found top TiO2 thickness of 350–400 nm or about 1170 nm showed high heat mirror performance. This thickness was enough to show the photo-catalytic properties. 相似文献
105.
The rust particles of Zn-Al-Mg alloys were synthesized from aqueous solutions dissolving ZnCl2, AlCl3, and MgCl2 at different atomic ratios of the metal ions. The crystal phase and particle morphology of the products depended on the composition of the starting solutions. The compactness of the layers of the products was estimated by measuring their air permeability. The layer of mixed metal hydroxide chloride formed at Zn:Al:Mg = 1:1:1 showed a highest compactness, that was ascribed to the preferred orientation of the fine plate particles. The addition of Mg(II) made plate particles smaller to give more compact layers. 相似文献
106.
107.
A needle penetrometry was performed loading steady force in a range from 1×10−3 to 2 N to pelletized coal upon heating via a cylindrical needle. From the observed effects of shear rate on apparent viscosity of softening coal pellet, defined as the shear-rate to shear-stress ratio, it was found that the pellet behaved as a Newtonian fluid for shear rates lower than a critical one while as a pseudo-plastic fluid for higher shear rates. The penetrometry was also carried out varying the force with time. The variable force loading enabled to maintain the shear rate well below the critical one, and thereby to measure the apparent viscosity of coal pellets as Newtonian fluids over a temperature range from 600 to 800 K. Upon heating at 10 K min−1, the apparent viscosity of Goonyella coal pellet decreased from about 1010 Pa s at 640 K down to a minimum of about 104 Pa s at 755 K, and increased up to 109 Pa s at 800 K. In a course of heating as above, the viscosity of Blind Canyon coal pellet decreased above 600 K, underwent a minimum of about 106 Pa s at 715 K, and increased up to 1010 Pa s at 770 K. Decreasing the heating rate from 10 to 3 K min−1 caused the minimum viscosities of the pellets to increase by 1-2 orders of magnitude. 相似文献
108.
Wai-Yim Ching Shang-Di Mo Lizhi Ouyang Paul Rulis Isao Tanaka Masato Yoshiya 《Journal of the American Ceramic Society》2002,85(1):75-80
The structure and properties of cubic spinel nitrides were investigated based on first-principles theoretical calculations. The lattice constants, bulk moduli, band structures, electronic bonding, and lattice stability of thirty-nine single and double nitrides were studied. The single spinel nitrides of the form c -A3 N4 (where A is a Group IVA element), except c -Hf3 N4 , are all semiconductors with band gaps ranging from an indirect gap of 0.07 eV in c -Ti3 N4 to a direct gap of 3.45 eV in c -Si3 N4 . For double nitrides of the form c -AB2 N4 (where A and B are Group IVA (Ti, Zr, Hf) or IVB (C, Si, Ge, Sn) elements), both metallic and insulating band structures are possible. The stability of the double spinel nitrides, relative to single nitrides, is dependent on the optimal cation radii and polyhedral volumes at the tetrahedral A sites and the octahedral B sites. Of the thirty-two double nitrides, only nine are predicted to be energetically favorable. Among the potentially stable phases, the most interesting ones are c -CSi2 N4 (which has an exceptionally strong covalent bonding and large bulk modulus), c -SiGe2 N4 (which has an energetically favorable direct band gap of 1.85 eV), and c -SiTi2 N4 (which is metallic). 相似文献
109.
Various characteristics of γ′/γ phase equilibrium in ternary Ni−Al-X alloys are analyzed by the cluster variation method (CVM)
with the phenomenological Lennard-Jones pair potential. Among the eleven alloy elements studied, three types of substitution
behavior in γ′,i.e., the preferential substitution for Ni sites (Co and Cu), the almost entire substitution for Al sites (Ti, Nb, Mo, Hf, Ta,
and W), and the substitution for both (Cr, Mn, and Fe), are recognized depending upon the relative magnitude of the Ni−X and
Al−X interactions. In the last type, the substitution site appears to depend remarkably upon the Al and/or X concentrations
in γ′: while X atoms enter preferentially, the Al sublattice in the case that the sum of the two concentations is less than
the stoichiometry composition (0.25), they begin to enter the Ni sublattice as the sum exceeds it. The predicted substitution
behavior is in good agreement with direct and indirect experimental evidences thus far reported. The direction of γ′/γ equilibrium
phase boundaries, the equilibrium partition coefficient of X, and the effects of alloying upon the order-disorder transformation
temperature from metastable γ′ to γ all appear to be closely related to substitution behavior. Also, the variation of lattice
constants of γ′ and γ with the alloy element concentration may be better understood by collation with the substitution sites
or the short range order in each phase. 相似文献
110.
Polypyrrole–PMMA composite films have been prepared with the chemical oxidative polymerization by spreading the water-insoluble solvent solution of pyrrole and PMMA mixture on the surface of the aqueous solution containing K2S2O8, the oxidizing agent. The conductivity of the films increases rapidly, passes through a plateau, and then decreases gradually as the reaction time increases. The conductivity of the oxidized side of the film is higher by over 1 order of magnitude than that of the evaporated side. It is due to the fact that the former is rich in polypyrrole while the latter is rich in PMMA. The thickness of the films can be controlled by adjusting the PMMA concentration. However, the lower limit of the film thickness is practically in submicron order. The relationship between the transmittance and the logarithm of the conductivity of the films gives a straight line with a gradient, ca. −8. The conductivity of the films is stable on silicagels in a desiccator over 2000 h at 25°C. The conductivity of the film is, however, very sensitive to the moisture in atmosphere and gives rise to decrease with humidity. 相似文献