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21.
Hirotaka SoHirofumi Watanabe Masayuki YahiroYu Yang Yuji OkiChihaya Adachi 《Optical Materials》2011,33(6):755-758
In this study, we synthesized the new spirobifluorene derivatives; hexylbiphenyl-spirobifluorene (HBP-Spiro) and triphenylamine-spirobifluorene (TPA-Spiro) and demonstrated the operation of a distributed-feedback polymer waveguide blue laser. In addition, we investigated the optical and lasing properties of spirobifluorene derivatives including photostability. The experimental slope efficiency and the energy threshold of a HBP-Spiro-doped waveguide laser were 3.6% and 1.9 μJ, respectively. An operation lifetime of 27,000 shots was obtained for a pump-pulse duration of 1.2 ns and energy of 3.0 μJ at a wavelength of 355 nm. 相似文献
22.
Seiji Kumagai Hirotaka Ishizawa Yuta Aoki Yasuhiro Toida 《Chemical engineering journal (Lausanne, Switzerland : 1996)》2010,156(2):270-277
A molded carbon/silica composite with high micro- and mesoporosity, as well as a high bulk density, was fabricated by activating a disk-molded precursor made from carbonized rice husk (RH) and beet sugar (BS) at 875 °C in CO2. The pore structure of the RH- and BS-based carbon/silica composite (RBC) was analysed in relation to the bulk density. An activation time of 2.0 h provided the largest BET specific surface area (1027 m2/g) and total pore volume (0.68 cm3/g) and a low bulk density (0.54 g/cm3). An RBC that was first activated for 1 h was immersed again in BS syrup and then activated in CO2 for 1 h. This two-step activation process provided both a high bulk density (0.69 g/cm3) and a highly textured structure (BET specific surface area, 943 m2/g; total pore volume, 0.56 cm3/g). The immersion in BS syrup was useful for improving the texture without reducing the bulk density, in comparison to one-step activation for 1.0 h. The suspension of the RBCs was basic because of the residual inorganic compounds of potassium and calcium. However, the basicity of the suspension was alleviated by washing the RBCs with water. 相似文献
23.
The thermo-emf ΔV of the touching p- and n-type Cu/Bi-Te/Cu composites with different thicknesses of t
Bi-Te and t
Cu was measured as a function of time by alternating the temperature difference ΔT at periods of T = 20, 60, 120, 240 and ∞ sec, where t
Bi-Te was varied from 0.1 to 2.0 mm and t
Cu from 0 to 4.0 mm. As a result, ΔV changes significantly with t
Bi-Te, t
Cu and T. The effective thermo-emf ΔV
eff increases significantly with an increase of 1/T and exhibited a local maximum at 1/T = 1/240 s−1. The resultant | α | and the effective temperature difference ΔT
eff were increased significantly by optimizing t
Bi-Te and t
Cu at 1/T = 1/240 s−1. The power generation ΔW
eff (= ΔV
eff2/4R
calc) estimated using the measured ΔV
eff and calculated R
calc also exhibited a local maximum at 1/240 s−1 for an optimum combination of t
Bi-Te = 0.1 mm and t
Cu = 2.0 mm, so that the maxima ΔW
eff at 1/T = 1/240 s−1 for the p- and n-type composites were 2.28 and 2.92 times higher than those obtained at 1/T = 0 s−1. This significant increase in ΔW
eff is owing to both the increase in ΔT
eff and the increase in ZT due to the increase in |α|. The power generation was thus found to be enhanced significantly by imposing the alternating
temperature gradients on touching Cu/Bi-Te/Cu composites. 相似文献
24.
Shoji Nagaoka Masanori Nagata Kenji Arinaga Kiyoshi Shigemori Makoto Takafuji Hirotaka Ihara 《Coloration Technology》2007,123(6):344-350
In order to develop environmentally friendly coloured materials, cellulose composite spherical microbeads hybridised with titanium dioxide (TiO2 ) particles and inorganic pigment were prepared by a phase-separation method using viscose and an aqueous solution containing sodium polyacrylate. Findings regarding the relationships between cellulose xanthate and the electronic characteristics of TiO2 particles used in the cellulose/inorganic material composite sphering process are also reported. These findings suggest that the location of TiO2 particles in cellulose microbeads is related to electrical repulsion between the xanthate (CSS− ) group and TiO2 . The use of TiO2 powder as colour pigment is limited, as its colour is white. The cellulose composite spherical microbeads covered with TiO2 and Fe2 O3 particles were developed by addition of iron oxide (Fe2 O3 ). Their surfaces were viewed by laser microscope and using SEM images. These composite microbeads retained the photocatalytic property of TiO2 . Cellulose/TiO2 /Fe2 O3 composite spherical microbeads with both colour function and photocatalytic properties were successfully prepared. 相似文献
25.
Microwave dielectric properties and crystal structures of Mg0.7Al2.2O4 and Mg0.4Al2.4O4 ceramics with defect structures 下载免费PDF全文
Susumu Takahashi Akinori Kan Hirotaka Ogawa 《Journal of the American Ceramic Society》2017,100(8):3497-3504
Mg0.7Al2.2O4 and Mg0.4Al2.4O4 ceramics with cation vacancies were synthesized using the molten salt method, and the relationships between the microwave dielectric properties and crystal structures of these materials were investigated. The 27Al NMR spectra of these ceramics indicate that the preferential occupation of tetrahedral sites by Al3+ cations was enhanced by the introduction of cation vacancies. The λ values of Mg0.7Al2.2O4 and Mg0.4Al2.4O4 ceramics fired at 1600°C, which correspond to the fraction of Al3+ cations in tetrahedral sites, were 0.37 and 0.60, respectively. Crystal structure refinements using the Rietveld method suggest that cation vacancies are preferentially located at octahedral sites in both ceramics. The εr and Q·f values of a Mg0.7Al2.2O4 ceramic fired at 1600°C were 7.7 and 201 111 GHz, respectively, while those of a Mg0.4Al2.4O4 ceramic fired at 1600°C were 7.5 and 232 301 GHz, respectively. These data demonstrate that the preferential occupation of tetrahedral sites by Al3+ cations following the introduction of cation vacancies enhances the Q·f value. 相似文献
26.
Akihiro Ishimi Kozo Katsuyama Koji Maeda Tsuyoshi Nagamine Takeo Asaga Hirotaka Furuya 《Journal of Nuclear Science and Technology》2013,50(12):1144-1155
The X-ray CT technology previously developed by JAEA was upgraded. The shape of the X-ray source beam was changed from a circular shape to an elliptical one and the collimator slit width was decreased from 0.3 to 0.1 mm. The X-ray detector was improved by changing a CdWO4 scintillator to a highly sensitive silicon semiconductor detector. The analysis code of X-ray CT image was revised with respect to the number of points by using two kinds of experimental results and taking into account the effects of crack existence and deviation of the central void position from the radial center of a fuel pellet. As a result, high resolution X-ray CT images could be obtained on the transverse cross section of irradiated fuel assemblies. The error of the dimensional measurement was improved from ±0.1 to ±0.03 mm by upgrading the instrument and revising the analysis code of X-ray CT image. The discriminating accuracy of density difference could be increased, and the low density region (undisturbed region) and high density region (equi-axial and columnar regions) in the X-ray CT image on the cross section of irradiated fuel could be discriminated from each other. The reliability of fuel performance analysis improves because a large number of PIE data can be collected, compared with the conventional destructive PIE. 相似文献
27.
Improved visible-light responsive photocatalytic activity of N and Si co-doped titanias 总被引:1,自引:0,他引:1
Thermal reaction of titanium tetraisopropoxide and tetraethyl orthosilicate in 1,4-butanediol afforded nanocrystalline silica-modified
titanias having large surface area and superior thermal stability. In this study, the thus-obtained silica-modified titanias
were treated in an NH3 flow at high temperatures, and their physical and photocatalytic properties were investigated. Compared with NH3-treated TiO2 without silica modification, the NH3-treated silica-modified titanias showed a stronger absorption in the visible region (400–500 nm) and had a larger peak at
396 eV in the N 1s XPS spectrum. These results indicate that a larger amount of nitrogen was stably doped in the silica-modified
titania. The obtained products exhibited a high photocatalytic activity for degradation of Rhodamine B and decomposition of
acetaldehyde under visible light irradiation.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
28.
Detection of Verotoxigenic Escherichia coli O157 and O26 in food by plating methods and LAMP method: a collaborative study 总被引:3,自引:0,他引:3
Hara-Kudo Y Konishi N Ohtsuka K Hiramatsu R Tanaka H Konuma H Takatori K 《International journal of food microbiology》2008,122(1-2):156-161
In order to establish a rapid and sensitive method for the detection of Verotoxigenic Escherichia coli O157 and O26, a collaborative study was conducted focusing on a comparison of the efficiency of loop-mediated amplification (LAMP) assay targeting the Verocytotoxin (also called Shiga toxin) gene, utilizing a direct plating method and a plating method with immunomagnetic separation (IMS-plating method) using various agar media. In combination with enrichment with the modified EC supplemented with novobiocin, E. coli O157 was detected in most samples of ground beef and alfalfa sprouts by LAMP assay, the direct plating method and the IMS-plating method. E. coli O26 was detected in approximately 100% of the food samples by LAMP assay. However, the IMS-plating and direct plating methods recovered 80 and 50% in ground beef samples, respectively. As a result, it was demonstrated the LAMP assay is superior to the IMS-plating method. Based on these results, it appears LAMP assay is effective as a screening assay to detect E. coli O157 and O26 from positive samples. 相似文献
29.
Kazuyuki Chihara Caroline F. Mellot Anthony K. Cheetham Shani Harms Hirotaka Mangyo Masaki Omote Ryuichi Kamiyama 《Korean Journal of Chemical Engineering》2000,17(6):649-651
Equilibrium and isosteric heat of adsorption for the system of chloroform and USY-type zeolite were studied. The USY-type zeolite (PQ Co., SiO2/Al2O3=70) was used both as a pure crystalline powder and as granulated particles with binder. Chloroform was reagent grade. The adsorption equilibria were measured using a gravimetric method and were expressed as isotherms. A chromatographic method (i.e. pulse response of chloroform through the USY column with helium carrier) was used to get the initial slope of the isotherms. In the simulation, the GCMC method was used to calculate amounts adsorbed for various conditions. FF parameters were confidently applied. And modified structure model was effective for simulation. This paper was presented at The 5th International Symposium on Separation Technology-Korea and Japan held at Seoul between August 19 and 21, 1999. 相似文献
30.
It is important to get a steady‐state operation of a power electronic circuit for its design. The shooting method, which is one of the steady‐state analysis methods, solves a boundary value condition which equates initial values to final values after one‐period transient. This paper proposes how to process the analysis in parallel by using a Parallel Virtual Machine (PVM3) system. In particular, the multiple shooting method (MSM) which divides the shooting time into subsections is suitable because it can parallel numerical processes for the divided shooting times by using multiple CPU units independently. This parallel method is applied to converter examples which are processes by PVM3. The computed results are investigated for their convergence and CPU times to check their parallel effects. According to the MSM algorithm, CPU times are reduced almost to one‐fifth by using five computer units from a PVM3 system example. © 2001 Scripta Technica, Electr Eng Jpn, 135(2): 69–76, 2001 相似文献