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111.
Ryuji Ukai Takuma Kuno Toshiteru Nakamura Masahito Uchiyama Satoshi Ouchi 《Journal of the Society for Information Display》2021,29(1):78-88
We have developed head‐mounted displays with high transmittance and luminance, which could be utilized outside safely without dimming glasses. We first specified required optical performance specifications by considering user's safety and usability. In order to ensure that the user is able to recognize both surrounding environment and the image of the head‐mounted display, we set the target specification that the transmittance is higher than or equal to 85%, and the luminance contrast ratio is larger than or equal to 1.15 with display image of white solid pattern. We then developed the beam‐splitter‐array waveguide to achieve the requirements. It has advantages in high efficiency and high see‐through property. In order to determine configuration of the waveguide, we have performed optical ray trace simulation. We also established versatile waveguide measurement method applicable to different‐type waveguides. By utilizing the waveguide we have developed, we made a prototype of a head‐mounted display (HMD) with high transmittance 94% and high luminance 4.8 × 103 cd/m2 and thus luminance contrast ratio 1.25 under the sun. With these advantages, our HMD is suitable for usage outside including applications of work support systems where dimming effect is not preferred, and the HMD is used under the sun. 相似文献
112.
K. Ouchi N. R. Stapleton B. C. Barber 《International journal of remote sensing》2013,34(18):3709-3718
During the joint U.K./U.S.A. experiment conducted in the Loch Linnhe, Scotland, U.K., in 1989, the Jet Propulsion Laboratory (JPL) multifrequency airborne synthetic aperture radar (SAR) was deployed to investigate the relation between the SAR images and ship-generated internal waves. One of the intriguing results, consistent throughout the experiment, was the striking difference in phase (position) between the images of internal wave wakes in the P-band ( 68cm) wavelength and those in L-band ( 24 cm) and C-band ( 6 cm) wavelengths. An explanation for this difference is found in the sensitivity of different radar wavelengths to oceanic surface waves in different ranges of wavelengths, that are perturbed by varying surface currents by different amounts and at different positions, depending on the wavelength of surface waves. 相似文献
113.
Takayuki Narushima Michihisa Kato Shin Murase Chiaki Ouchi Yasutaka Iguchi 《Journal of the American Ceramic Society》2002,85(8):2049-2055
The oxidation behavior of a silicon wafer, chemically vapor-deposited SiC, and single-crystal SiC was investigated in an oxygen—2%–7% ozone gas mixture at 973 K. The thickness of the oxide film that formed during oxidation was measured by ellipsometry. The oxidation rates in the ozone-containing atmosphere were much higher than those in a pure oxygen atmosphere. The parabolic oxidation kinetics were observed for both silicon and SiC. The parabolic rate constants varied linearly with the ozone-gas partial pressure. Inward diffusion of atomic oxygen formed by the dissociation of ozone gas through the SiO2 film apparently was the rate-controlling process. 相似文献
114.
Shigehiro?IshizukaEmail author Anas?Iswandi Yasuhiro?Nakajima Seiichirou?Yonemura Shigeto?Sudo Haruo?Tsuruta Daniel?Murdiyarso 《Nutrient Cycling in Agroecosystems》2005,71(1):17-32
We measured fluxes of three greenhouse gases (N2O, CO2O and CH4) from soils of six different land-use types at 27 temporary field sites in Jambi Province, Sumatra, Indonesia. Study sites included natural and logged-over forests; rubber plantation; oil palm plantation; cinnamon plantation; and grassland field. The ranges of N2O, CO2 and CH4 fluxes were 0.13–55.8 gN m-2h-1; 1.38–5.16 g C m-2d-1; –1.27–1.18 mg C m-2d-1, respectively. The averages of N2O, CO2 and CH4 fluxes at 27 sites were 9.4 gN m-2h-1,3.65 g C m-2d-1, –0.45 mg C m-2d-1, respectively. The values of CO2 and CH4 fluxes were comparable with those in the reports regarding other humid tropical forests, while the N2O flux was relatively lower than those of previous reports. The N2O fluxes in each soil type were correlated with the nitrification rates of soils of 0–5 cm depth. In Andisols, the ratio of the N2O emission rate to the nitrification rate was possibly smaller than that of the other soil types. There was no clear relationship between N2O flux and the soil water condition, such as water-filled pore space. Seventeen percent of CH4 fluxes were positive; according to these positive fluxes, we did not find a good correlation between CH4 uptake rate and soil properties. Although we performed a chronosequence analysis to produce some hypotheses about the effect of land-use change by a limited amount of sampling at one point in time, further tests are required for the future. 相似文献
115.
116.
Model organic compounds have been subject to hydrogenolysis reactions using CO and H2O under industrial conditions as used for lignite and residual oil. Twenty-eight compounds, including diphenylmethane, indane, tetralin, anthracene, diphenyl ether, indene, benzophenone and xanthene were used. The purpose is to study the hydrogenolysis behaviour of compounds with structures as found in coal and residual oil. Using a Co-Mo catalyst, scission of the CC chain connecting two aromatic rings is enhanced by increased chain length of the molecule. Ether bonds are broken more easily than CC bonds. With the exception of decalin, cyclic CC bonds are more resistant to cleavage than linear bonds. Alcohol hydroxyl, and carbonyl groups of stilbene are the easiest to reduce but phenolic hydroxyl groups are stable. The Co-Mo catalyst promoted hydrolysis of ether bonds as well as hydrogenolysis. The method of the study is considered to be more effective for hydrogenolysis of organic compounds than the reported use of alkali and tetralin because of milder reaction conditions which are required. 相似文献
117.
118.
Use of asphaltene instead of the parent coal as the starting material for hydrogenolysis makes it easier to discuss the reaction mechanism, because the mean chemical structures of both reactant and products can be deduced from structural analysis. In this study asphaltene from Japanese Akabira coal was hydrogenated at 400 or 370 °C under initial pressures of 9.8 or 10.4 MPa using red-mud and sulphur catalyst. The structures of the products (oil and remaining asphaltene) and of the original asphaltene were analysed statistically by n.m.r. data. Most of the conversion of asphaltene to oil was caused by saturation of aromatic rings, decomposition of naphthenic rings, dehydroxylation and the decrease of inert (O + N + S) elements resulting from the opening of hetero-rings; the splitting of linkages between unit structures did not contribute to the conversion. 相似文献
119.
Poly(vinylidene chloride) — PVDC — and poly(vinyl chloride) — PVC — reacted with pitches at elevated temperature with an increase in the yield of residual carbon; the greater the aromaticity and ‘fixed carbon’ of the pitch, the greater the increase. PVDC especially had a remarkable effect. This increase of residual carbon may be due to an increase in the molecular weight of pitch produced by its reaction with PVDC or PVC via dehydrochlorination. This tends to elevate the softening point and increase the insolubility in solvents. It is clearly indicated from i.r. spectra that reaction takes place mainly between aromatic hydrogen in the pitch and chlorine in PVDC. X-ray diffraction profiles of the reaction products show that the pitch forms hard (non-graphitizing) carbon as the PVDC content in the mixture increases. 相似文献
120.
Methanol was used as an in-situ hydrogen source, following its decomposition over ZnO-Cr2O3, for the hydrogenation of coal. The reaction was carried out in a high pressure autoclave at ≈400–440 °C, in the presence of different hydrogenation catalysts. Stabilized nickel, stabilized Co and Ni-Cr-Cu catalysts gave excellent results. The maximum conversion was 100% for pyridine, 94.4% for benzene and 66.2% for straight-chain hexane. 相似文献