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排序方式: 共有833条查询结果,搜索用时 15 毫秒
71.
In this study, we used the minute gas–liquid interfaces around CO2/NH3 microbubbles as new reaction fields where the crystal nucleation progresses and developed a crystallization technique to control the polymorphism of calcium carbonate (CaCO3). In the regions around the gas–liquid interfaces of CO2/NH3 microbubbles, Ca2+ and CO32− ion concentrations can be adjusted because of the characteristic of the electric charge on the bubble surface and the decrease in CO2 concentration based on unit bubble caused by minimization of bubble size, and because of the pH difference between local pH at the gas–liquid interface and overall pH in the bulk liquid caused by mixing of NH3 with CO2; hence, the polymorph change of CaCO3 is expected to occur. CaCO3 was crystallized at 298 K by a semi-batch type reaction in which CO2/NH3/N2 bubbles were continuously supplied to an aqueous Ca(NO3)2 solution using a self-supporting bubble generator. The solution pH during crystallization was maintained at a constant level of 6.9–12.0 by adding HNO3 and NH4OH solution. The average bubble size (dbbl) was varied in the range of 40–1000 μm by controlling the N2 flow rate, and the molar ratio of CO2/NH3 (αCO2/NH3) was set at a specified value of 0.20–1.00 at a constant CO2 flow rate. The following results were obtained by varying solution pH, dbbl, and αCO2/NH3: at a constant dbbl of 40 μm and αCO2/NH3 of 0.20, vaterite and calcite were major products at a solution pH lower than 9.0 and at a solution pH greater than 11.0, respectively, while aragonite was crystallized predominantly in the solution pH range of 9.7–10.5; at a constant solution pH of 9.7 the crystallization of aragonite was accelerated remarkably with a decrease in αCO2/NH3 and dbbl. 相似文献
72.
Miwa N Nishio T Arita Y Kawamori F Masuda T Akiyama M 《Shokuhin eiseigaku zasshi. Journal of the Food Hygienic Society of Japan》2003,44(6):289-293
Vibrio parahaemolyticus densities in spiked and naturally contaminated seafood samples were enumerated by the MPN method combined with a PCR procedure (MPN-PCR method) targeting the species-specific thermolabile hemolysin gene (tlh), and by the MPN method using subcultivation of alkaline-peptone-water (APW) enrichment culture on thiosulfate-citrate-bile-sucrose (TCBS) agar (MPN-TCBS method). In the samples spiked with both V. parahaemolyticus and V. alginolyticus, the numbers of V. parahaemolyticus enumerated by the MPN-PCR method were similar to, or higher than the numbers of spiked cells, whereas those enumerated by the MPN-TCBS method were below the numbers of spiked cells. In naturally contaminated seafood samples, the numbers of V. parahaemolyticus enumerated by the MPN-PCR method were higher than those by the MPN-TCBS method. In the case of the MPN-TCBS method, isolation of V. parahaemolyticus from some APW cultures was difficult because of the overgrowth of many colonies other than V. parahaemolyticus (e.g., V. alginolyticus) on TCBS agar. In contrast, the PCR technique could detect tlh from APW culture without isolation of V. parahaemolyticus, so the possibility of failing to obtain a positive result in APW culture by the MPN-PCR method was considered to be lower than that by the MPN-TCBS method. Furthermore, utilization of the PCR technique reduces the time and labor required for the biochemical identification tests used in the MPN-TCBS method. For the detection and enumeration of V. parahaemolyticus in seafood, especially for samples that show many colonies other than V. parahaemolyticus on TCBS agar, the MPN-PCR method may be more convenient and reliable than the MPN-TCBS method. 相似文献
73.
Tomohiro Itoh Kenji Ohguchi Chizuru Nakajima Masayoshi Oyama Munekazu Iinuma Yoshinori Nozawa Yukihiro Akao Masafumi Ito 《Food chemistry》2011
We found that two distinct flavonoid glycosides isolated from the peel of Japanese persimmon (Diospyros kaki Fuyu), isoquercitrin (Isq) and hyperin (Hyp), are capable of inhibiting antigen-stimulated degranulation in rat basophilic leukaemia RBL-2H3 cells. In order to elucidate the underlying mechanisms, we examined effects of Isq and Hyp on cellular responses induced by antigen stimulation. Treatment with both Isq and Hyp markedly inhibited antigen-stimulated elevation of intracellular free Ca2+ concentration and reactive oxygen species (ROS). Isq and Hyp did not affect NADPH oxidase (NOX) activity, but they possessed DPPH radical-scavenging activity similar to that of epigallocatechin gallate, a potent anti-oxidant, Finally, Isq and Hyp showed little or no effects on Ag-stimulated Syk activation or phosphorylation of signalling molecules. These results indicate that inhibition of antigen-stimulated degranulation by Isq and Hyp is mainly due to suppression of intracellular Ca2+ elevation, which is caused by direct scavenging of ROS that are generated by NOX. Our findings suggest that Isq and Hyp, isolated from the peel of persimmon, would be beneficial for alleviating symptoms of type I allergy. 相似文献
74.
Yosuke Higo Fusao Oka Tomohiro Sato Yoshiki Matsushima Sayuri Kimoto 《Soils and Foundations》2013,53(2):181-198
In this paper, localized deformation in partially saturated sand was investigated quantitatively using microfocus X-ray computed tomography (CT) and an image analysis of the CT images. Triaxial compression tests on a partially saturated dense Toyoura sand specimen were carried out under a low confining pressure and under drained conditions for both air and water. The development of localized deformation was observed macroscopically using microfocus X-ray CT, and the displacement field over the entire specimen was quantified by an image analysis of the CT images with the digital image correlation (DIC) technique. The progressive development of shear bands is discussed with reference to these images. In addition, the region of localization was observed microscopically by partial CT scanning on a micron scale with high spatial resolution. Changes in the particulate structures are also discussed herein. The DIC image analysis of the partial CT images provided a microscopic displacement field and indicated that very fine localized shear deformation developed before the shear bands had become visible in the macroscopic investigation. 相似文献
75.
Shun HiroiSou Hosokai Tomohiro Akiyama 《International Journal of Hydrogen Energy》2011,36(2):1442-1447
This paper describes the ultrasonic irradiation on the hydrolysis of magnesium hydride to enhance hydrogen generation; the effects of the ultrasonic frequency and the sample size on the hydrogen generation were mainly examined. In the experiments, three MgH2 particle and nanofiber samples were soaked in distilled water and ultrasonically irradiated at frequencies of 28, 45, and 100 kHz. Then, the amount of hydrogen generated was measured. We found that the low frequency of ultrasonic irradiation and the relatively small sample size accelerated the hydrolysis reaction MgH2 + 2H2O = Mg(OH)2 + 2H2 + 277 kJ. In particular, the MgH2 nanofibers exhibited the maximum hydrogen storage capacity of 14.4 mass% at room temperature at a frequency of 28 kHz (ultrasound irradiation). The results also experimentally validated that a combination of ultrasonic irradiation and MgH2 hydrolysis is considerably effective for efficiently generating hydrogen without heating and adding any agent. 相似文献
76.
Takashi Wakuda Kazuo Azuma Hiroyuki Saimoto Shinsuke Ifuku Minoru Morimoto Ichiro Arifuku Masahito Asaka Takeshi Tsuka Tomohiro Imagawa Yoshiharu Okamoto Tomohiro Osaki Saburo Minami 《Journal of Functional Foods》2013,5(1):516-523
The effects of pear vinegar (PV), which was specially brewed for enhanced galacturonic acid content, on the DSS-induced ulcerative colitis (UC) mouse model were evaluated. PV improved clinical symptoms, colon inflammation, and histological tissue injury in the DSS-induced acute UC mouse model. Moreover, PV suppressed inflammation due to acute UC by suppressing the myeloperoxidase (MPO)-mediated activation of inflammatory cells such as leukocytes and decreasing the serum concentration of IL-6. Our results demonstrated the protective action of PV in the DSS-induced acute UC mouse model. On the other hand, commercial apple vinegar did not show a protective effect in the DSS-induced acute UC mouse model. Our findings indicate that PV may act as a new functional food for inflammatory bowel disease patients. 相似文献
77.
Naoki Yashiro Tomohiro Usui Koichi Kikuta 《Journal of the European Ceramic Society》2010,30(10):2093-2098
The application of an inkjet printing process for fabricating solid oxide fuel cell (SOFC) cathodes was investigated. Stably-dispersed LSCF–GDC inks were prepared by ball milling, and the composition was easily controlled by the preparation process. Fabrication of an LSCF–GDC layer was successfully carried out by depositing dots and the thickness was easily controlled by repeating printing process. A planar SOFC single cell with a double-layered cathode (comprised of a paste painted cathode layer and an inkjet printed interlayer) achieved a maximum power density of 0.71 W/cm2 at 600 °C. This is the preliminary work for fabricating the cathode layer of a SOFC single cell via inkjet printing. 相似文献
78.
Tomohiro Isogai Kazuhiro Hirooka Tetsuro Tojo Hitoshi Takebayashi Morihiro Saito Minoru Inaba Akimasa Tasaka 《Electrochimica acta》2011,56(12):4425
Metal fluoride added carbon anodes treated by pre-electrolysis were investigated for electrolytic production of nitrogen trifluoride (NF3) in molten NH4F·KF·4HF at 100 °C. The conditions for pre-electrolysis were first optimized using a graphite sheet anode as a model anode. The formation of fluorine-graphite intercalation compounds (fluorine-GICs) with semi-covalent C–F bonds, (CxF)n, on the MgF2 and CaF2 added carbon anode surface was accelerated by pre-electrolysis at potentials less than 4.0 V. Critical current densities (CCD) on the MgF2 added carbon anodes pre-electrolyzed under various conditions were determined, and the highest CCD was 290 mA cm−2 obtained for that pre-electrolyzed at 3.5 V for 500 C cm−2. This anode was successfully used in the electrolysis at 100 mA cm−2 for 290 h and the maximum NF3 current efficiency was 55%. From these results, it was concluded that the metal fluoride added carbon anode treated by pre-electrolysis has a high potential for electrolytic production of NF3 at higher current density. 相似文献
79.
Lu Yang Tomohiro Yendo Mehrdad Panahpour Tehrani Toshiaki Fujii Masayuki Tanimoto 《Journal of Visual Communication and Image Representation》2010,21(5-6):542-560
In this paper, we present a new view synthesis method in multiview camera configurations of Free viewpoint TV (FTV) where potential depth errors are considered. The emphasis is on the artifacts eliminating for photorealistic synthesis especially near object boundaries. In contrast to conventional techniques which ignore geometry errors, we first categorize the artifact cases and depth modes. Furthermore, this paper infers the complementarity principle of the artifacts from left and right references. This complementarity guarantees the effectiveness of our reliability-based synthesis. The reliability reasoning is crucial for artifacts reduction. The reliable and unreliable areas from different views can be correctly labeled. Then artifacts caused by unreliable pixels from one reference can be replaced by the reliable pixels from the other reference. As a final result, artifacts of novel view are demonstrated to be significantly reduced on different multiview sequences. 相似文献
80.
Takehiko Watanabe Masataka ShirokiAtsushi Yanagisawa Tomohiro Sasaki 《Journal of Materials Processing Technology》2010,210(12):1646-1651
Authors investigated the effect of ultrasonic vibration on the solidification microstructure and mechanical properties of the weld metal of ferritic stainless steel by introducing directly ultrasonic vibration into the weld molten pool using ultrasonically vibrating filler metal. The main results obtained in this study are as follow. 相似文献