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31.
Yasushi Takeuchi Kohjiro Yanagisawa Yuhsuke Tanaka Noriyuki Tsuruoka 《Korean Journal of Chemical Engineering》1997,14(5):377-381
Fixation of nitrogen oxides (NOx) in air onto granular activated carbon impregnated with chemicals was attempted to improve removal efficiency of NOx by activated carbon adsorption. Nitric oxide (NO) and nitrogen dioxide (NO2), were tried to remove by a flow test. Fixed-bed adsorption breakthrough curves were obtained when some kinds of carbon were
used. The amount adsorbed of NO2 changed with the amount and kinds of metallic salts impregnated. Chemicals-impregnated carbons were prepared from a commercial
activated carbon. Among obtained carbons, the one which showed the highest selectivity for NOx was chosen, and its performance with the change in humidity was determined. Removal mechanism of NO2 was estimated, and the carbon impregnated with potassium hydroxide was found to be superior to any other carbon tested. The
amount of the adsorbed NO and that produced by the reduction of NO2 were determined from the breakthrough curves. 相似文献
32.
Masakazu Anpo Shinya Higashimoto Masaya Matsuoka Nurbosyn Zhanpeisov Yasushi Shioya Stanislaw Dzwigaj Michel Che 《Catalysis Today》2003,78(1-4):211-217
V-silicalite catalysts (VS-1 and VS-2) prepared by hydrothermal synthesis have been studied by ESR, XAFS (XANES and EXAFS) and photoluminescence spectroscopy. The in situ characterization of these V-silicalites shows that vanadium is present within the zeolitic framework as a highly dispersed tetrahedrally coordinated V-oxides, VO4 unit, having a short V=O bond length. Photoluminescence spectroscopy in static and dynamic mode, as well as XAFS studies allow to detect in the V-silicalites different V species than that present in V-HMS or V/SiO2, in terms of V=O bond length, vibrational energy,
bond angle and lifetime of the excited triplet state. It is suggested that the combined contribution of the neighboring Si---OH group attached to the VO4 unit and the zeolitic rigid framework structure of V-silicalites cause a more significant and pronounced effect on the chemical properties of the VO4 unit than the flexible structure of V-HMS or V/SiO2. Moreover, the dynamic quenching of the phosphorescence by the addition of reactant molecules such as NO or propane indicates that the V species in the excited triplet state can be expected to be the active sites for the photocatalytic reactions. 相似文献
33.
Kimihiro Yamashita Motohide Matsuda Yasushi Inda Takao Umegaki Masayuki Ito Toshinori Okura 《Journal of the American Ceramic Society》1997,80(7):1907-1909
Dielectric depression and dispersion were observed in BaTiO3 ceramic films fabricated by electrophoretic deposition followed by sintering. The dielectric constants were depressed down to 6800–4600 around the Curie point ( T C ). The dielectric dispersion occurred above T C . These dielectric properties are attributable to a surface layer formed during sintering. XRD analysis indicated that the surface layer was a hexagonal-like BaTiO3 phase. A mixed solvent of acetylacetone and alcohol employed in the present work may have been responsible for the formation of the surface layer. 相似文献
34.
Satoshi lio Masakazu Watanabe Masaru Matsubara Yasushi Matsuo 《Journal of the American Ceramic Society》1989,72(10):1880-1884
The improvement of mechanical properties of Al2 O3 /SiC whisker composites has been studied with emphasis on the effects of the whisker content and of the hot-pressing temperature. Mechanical properties such as fracture toughness and fracture strength increased with increasing whisker content up to 40 wt%. In the case of the high SiC whisker content of 40 wt%, fracture toughness of the sample hot-pressed at 1900° decreased significantly, in spite of densification, compared with one hot-pressed at 1850°. Fracture toughness strongly depended on the microstructure, especially the distribution of SiC whiskers rather than the grain size of the Al2 O3 matrix. 相似文献
35.
Koji Matsui Nobukatsu Ohmichi Michiharu Ohgai Naoya Enomoto Junichi Hojo 《Journal of the American Ceramic Society》2005,88(12):3346-3352
The sinterabilities of fine zirconia powders including 5 mass% Y2 O3 were investigated, with emphasis on the effect of Al2 O3 at the initial sintering stage. The shrinkage of powder compact was measured under constant rates of heating (CRH). The powder compact including a small amount of Al2 O3 increased the densification rate with elevating temperature. The activation energies at the initial stage of sintering were determined by analyzing the densification curves. The activation energy of powder compact including Al2 O3 was lower than that of a powder compact without Al2 O3 . The diffusion mechanisms at the initial sintering stage were determined using the new analytical equation applied for CRH techniques. This analysis exhibited that Al2 O3 included in a powder compact changed the diffusion mechanism from grain boundary to volume diffusions (VD). Therefore, it is concluded that the effect of Al2 O3 enhanced the densification rate because of decrease in the activation energy of VD at the initial sintering stage. 相似文献
36.
Amr Almaddah Sadi Vural Yasushi Mae Kenichi Ohara Tatsuo Arai 《Machine Vision and Applications》2014,25(4):845-857
As part of the face recognition task in a robust security system, we propose a novel approach for the illumination recovery of faces with cast shadows and specularities. Given a single 2D face image, we relight the face object by extracting the nine spherical harmonic bases and the face spherical illumination coefficients by using the face spherical spaces properties. First, an illumination training database is generated by computing the properties of the spherical spaces out of face albedo and normal values estimated from 2D training images. The training database is then discriminately divided into two directions in terms of the illumination quality and light direction of each image. Based on the generated multi-level illumination discriminative training space, we analyze the target face pixels and compare them with the appropriate training subspace using pre-generated tiles. When designing the framework, practical real-time processing speed and small image size were considered. In contrast to other approaches, our technique requires neither 3D face models nor restricted illumination conditions for the training process. Furthermore, the proposed approach uses one single face image to estimate the face albedo and face spherical spaces. In this work, we also provide the results of a series of experiments performed on publicly available databases to show the significant improvements in the face recognition rates. 相似文献
37.
The diffusion coefficient (D) values of tert‐butyloxycarbonyl‐glycine, tert‐butyloxycarbonyl‐L ‐tryptophan, tert‐butyloxycarbonyl‐L ‐phenylalanine (Boc‐Phe), and 9‐fluorenylmethoxycarbonyl‐L ‐phenylalanine in Merrifield polystyrene (MPS) gels, poly(ethylene glycol)‐grafted polystyrene (PEG–PS) gels, and crosslinked ethoxylate acrylate (CLEAR) gels, as used in solid‐phase peptide synthesis, were determined by the pulsed‐field‐gradient spin‐echo 1H‐NMR method. From these experimental results, it was found that the amino acids in MPS gels, PEG–PS gels, and CLEAR gels with N,N‐dimethylformamide‐d7 (DMF‐d7) as a solvent had multidiffusion components within a measurement timescale of 10 ms. The D value of Boc‐Phe in polystyrene gels (1% divinylbenzene crosslinked) with tetrahydrofuran‐d8 was much larger than that in the same gels with DMF‐d7. Furthermore, the required time in which an amino acid transferred from a reactive site to a reactive site was estimated, within which the solvents and amino acids in the polymer supports diffused in the swollen beads.© 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 413–421, 2003 相似文献
38.
A -conjugated polymer, poly(pyridine-2,5-diyl) (PPy) was investigated as a support for CuCl2 in the synthesis of dimethyl carbonate by oxidative carbonylation of methanol. The PPy–CuCl2 adduct had high catalytic activity which was comparable to that of the homogeneous CuCl2 catalyst. The adduct caused corrosion of stainless-steel vessels only to minor extent, compared with the homogeneous CuCl2 catalyst. This PPy–CuCl2 catalyst was easily recycled by filtration and showed a similar catalytic activity in the third time use. The presence of the -conjugated system in PPy, through which electrons can move, may bring about the high catalytic activity for the oxidative carbonylation of methanol, which involves Cu(II)/Cu(I) redox processes. 相似文献
39.
Masahiro Tajima Miki Niwa Yasushi Fujii Yutaka Koinuma Reiji Aizawa Satoshi Kushiyama Satoru Kobayashi Koichi Mizuno Hideo Ohuˆchi 《Applied catalysis. B, Environmental》1997,12(4):1418
The decomposition of chlorofluorocarbons (CFCs) in the presence of water was examined over a variety of solid acid catalysts. The TiO2ZrO2 catalyst was found to have the highest activity and longest life among the catalysts examined. The activity of the TiO2ZrO2 catalysts depended upon the content of TiO2. At the contents of TiO2 from 58 to 90 mole%, the TiO2ZrO2 catalysts exhibited high activity, and these catalysts were proven to contain TiZrO4 crystal. From the study of the XRD peak intensity of the TiZrO4 crystal, it was highest on the TZ-58 which contained 58 mole% of TiO2, and decreased with increasing the content of TiO2. Furthermore, the conversion of CFC113 measured at 673 K was highest at TZ-58, and decreased gradually with increasing TiO2 content. Therefore, the TiZrO4 crystal influences the activity of decomposition of CFC113. However, the TiO2ZrO2 catalyst was gradually deactivated during the reaction due to the elimination of titanium atoms. A good relationship was found between the activity on TiO2ZrO2 catalyst and bond energy of CCl in the compounds of chlorofluorocarbons and hydrochlorocarbons, suggesting that the rate controlling step was the cleavage of CCl bond. 相似文献
40.
Antioxidant effects of chlorophyll and pheophytin on the autoxidation of oils in the dark. I. Comparison of the inhibitory effects 总被引:1,自引:0,他引:1
Yasushi Endo Richiro Usuki Takashi Kaneda 《Journal of the American Oil Chemists' Society》1985,62(9):1375-1378
The effects of chlorophyll and pheophytin on the autoxidation of oils in the dark were investigated by oven tests. The results
indicated that both chlorophyll and pheophytin show antioxidant activity when methyl linoleate is used as substrate. Furthermore,
chlorophyll retarded the oxidative deterioration of triglycerides in rapeseed and soybean oils at 30 C. Among the four chlorophyll
derivatives (chlorophylls a and b and pheophytins a and b), chlorophyll a showed the strongest antioxidant activity. The antioxidant
effects of chlorophyll and pheophytin depended on the storage temperature and the kinds of oil used as substrate. 相似文献