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排序方式: 共有191条查询结果,搜索用时 15 毫秒
51.
Hidenobu Sumitani Sachiko Suekane Aya Nakatani Kiyoaki Tatsuka 《Journal of the science of food and agriculture》1997,75(1):73-79
White peach (Prunus persica L cv Yamane) homogenates with sugar (20%), or with sugar (20%) and/or L -ascorbic acid (0·1%) and/or sodium chloride (0·5%), were packed in plastic bottles, pressurised (400 MPa, 20°C, 10 min), and then stored at 0 and 25°C for various periods. The headspace volatiles which were absorbed on Tenax TA using dynamic headspace sampling were heat desorbed and analysed by capillary gas chromatography mass spectrometry. Enzymatic formation of benzaldehyde during storage was observed in all samples. The homogenate with L -ascorbic acid showed the highest level of benzaldehyde formation. The flavour quality and colour of the pressurised homogenates with ascorbic acid stored at lower temperature were excellent. © 1997 SCI. 相似文献
52.
ABSTRACT: The morphological change of silicon macropore arrays formed by metal-assisted chemical etching using shape-controlled Au thin film arrays was investigated during anisotropic chemical etching in tetramethylammonium hydroxide (TMAH) aqueous solution. After the deposition of Au as the etching catalyst on (111) silicon through a honeycomb mask prepared by sphere lithography, the specimens were etched in a mixed solution of HF and H2O2 at room temperature, resulting in the formation of ordered macropores in silicon along the [111] direction, which is not achievable by conventional chemical etching without a catalyst. In the anisotropic etching in TMAH, the macropores changed from being circular to being hexagonal and finally to being triangular owing to the difference in etching rate between the crystal planes. 相似文献
53.
A microwave-hydrothermal treatment with 1 and 5N-NaOH solution was used at 150°C and 190°C to dissolve excess silica glass and thus make porous mullite ceramics from a fired New Zealand kaolin honeycomb. The effect of microwave-hydrothermal (M-H) treatment time on the dissolution of the glass was examined and compared to the result of conventional-hydrothermal (C-H) treatment. As expected, the rate of the dissolution of glass was faster with M-H treatment compared to C-H treatment. The dissolution of 40–43% glass was almost complete after M-H treatment in 1N-NaOH for 6 hrs at 150°C, in1N-NaOH for 3 hrs at 190°C, in5N-NaOH for 1.5 hrs at 150°C, and in 5N-NaOH for 35 minutes at 190°C. When the M-H treatment in 5N-NaOH solution at 190°C was more than 45 minutes, nonporous prismatic crystals were formed on the honeycomb and these crystals decreased the specific surface area. There were no changes in the morphology of mullite whiskers or in the structure of porous mullite body after M-H treatments in NaOH solutions compared to that of C-H treatment. The M-H treatment has been shown to be a rapid technique to prepare porous mullite ceramics from fired kaolin honey comb. 相似文献
54.
Sachiko Sakura 《Electrochimica acta》1992,37(15):2731-2735
Electrochemiluminescence (ECL) was used to detect tryptophan in aqueous solutions in the presence of a brominating agent. Using platinum and glassy carbon electrodes, the ECL mechanism of tryptophan was studied. Tryptophan was oxidized at 0.78 V vs. sce in 0.1 M NaOH aqueous solution to the excited intermediate at a platinum electrode (0.44 V at a glassy carbon electrode). The intermediate was further oxidized and emitted light. The ECL signal was clearly observed when the applied potential was enough to oxidize the tryptophan. The ECL spectrum was measured, showing maximum emission peaks at 544 nm, 434 nm and 404 nm. Above 1.0 V, the brominating agent was oxidized which results in suppression of the ECL signal. A weak ECL signal was observed at an applied potential below 0.5 V, which indicates that this reaction is chemiluminescence (CL), enhanced by the applied potential. This method cannot be used for routine analysis because of the high detection limit of tryptophan (1.0 μmol), but can be used to obtain emission mechanism information. 相似文献
55.
A diffusive badge sampler for volatile organic compounds in ambient air and determination using a thermal desorption-GC/MS system. 总被引:2,自引:0,他引:2
Noriko Yamamoto Tomoko Matsubasa Nami Kumagai Sachiko Mori Koji Suzuki 《Analytical chemistry》2002,74(2):484-487
A sensitive personal badge sampler packed with Carbopack B for ambient levels of volatile organic compounds and an analytical system using a thermal desorption-preconcentration-GC/MS have been developed. The capacity of the new sampler was sufficient for an 8-h sampling period, and the analytical method was sensitive enough for the measurement of sub-ppb levels for a 2-h sampling period. The samplers were compared to diffusive samplers (OVM 3500) for typical environmental concentrations. There was a good correlation between the results obtained with the new samplers and the OVM samplers. 相似文献
56.
Bonding in fabric-cement systems: Effects of fabrication methods 总被引:1,自引:0,他引:1
This paper compares the effects on the bond between fabric and cement matrix of three different processing methods: casting, pultrusion and vacuum condition. The fabrics included bonded glass mesh, woven polyvinylalcohol, and warp knitted weft insertion polypropylene. Pullout tests were performed to examine the bond between fabric and cement matrix. A microstructural analysis was conducted and correlated with pullout data. Improved bonding was obtained for fabric-cement composites produced with the pultrusion process, particularly for fabrics composed of multifilament yarns that have open junction points and no sizing to seal individual yarns. This improved bonding results from the impregnation of the fabric in the cement chamber during the pultrusion process, which filled the spaces between the filaments of the multifilament yarns. 相似文献
57.
Masaru Sato Hiroaki Tanaka Koji Inaka Shinichi Shinozaki Ari Yamanaka Sachiko Takahashi Mari Yamanaka Erika Hirota Shigeru Sugiyama Mitsuyasu Kato Chie Saito Satoshi Sano Moritoshi Motohara Tai Nakamura Tomoyuki Kobayashi Susumu Yoshitomi Tetsuo Tanaka 《Microgravity science and technology》2006,18(3-4):184-189
Since 2003, Japan Aerospace Exploration Agency (JAXA, former NASDA) has been conducting a project on a semi-annual basis (JAXA-GCF) to obtain high-quality protein crystals in the microgravity environment using the Russian transportation system. For this project, protein samples were mostly provided by Japanese users for whom JAXA provided technical and clerical support for crystallization experiments in microgravity. For the project, JAXA has constructed a user-friendly support service for microgravity experiments and provided regular and frequent flight opportunities. To simplify and improve technological matters, JAXA devised a gel-tube method crystallization device, which is effective both in space and on ground, based on the counter-diffusion technique. JAXA also provided ground-based techniques for efficient preliminary optimization of crystallization conditions using a 1-dimensional simulation and for harvesting and cryoprotecting crystals before X-ray diffraction experiments. These improvements have significantly increased the success rate of obtaining useful results. In conclusion, JAXA has developed technologies for growing, in microgravity, high-quality protein crystals, which may diffract up to atomic resolution, for a better understanding of 3-dimensional protein structures through X-ray diffraction experiments. 相似文献
58.
Hiromi Yoshida Junji Shigezaki Sachiko Takagi Goro Kajimoto 《Journal of the science of food and agriculture》1995,68(4):407-415
Seeds from various strains of cultivated Sesamum indicum Linn (colour of seeds: black, brown and white) were exposed to microwave roasting for 16 and 30min at a frequency of 2450 MHz and were studied not only for different acyl lipids and their fatty acid compositions, but also for the contribution of anti-oxidants to the oxidative stability of the oils. Lipids from all-seeded strains were comparable in their total fatty acid composition, with linoleic, oleic, stearic and palmitic acids as the major acids. The total lipids were isolated by thin-layer chromatography into the following five fractions: triacylglycerols (TAG), diacylglycerols, free fatty acids, polar lipids and steryl esters. The TAG were slightly and randomly hydrolysed by microwaves, but was still representing 900 g kg?1 of the total lipids at 30min of roasting. Although burning and bitter tastes occurred at the time, the tocopherols and lignans still amounted to over 80% of the original level. The results suggested that the oxidative stability of the oils would probably be due to the synergism between endogenous antioxidants and browning substances produced during microwave roasting. 相似文献
59.
60.
Distribution of storage proteins in low-glutelin rice seed determined using a fluorescent antibody 总被引:4,自引:0,他引:4
Furukawa S Mizuma T Kiyokawa Y Masumura T Tanaka K Wakai Y 《Journal of Bioscience and Bioengineering》2003,96(5):467-473
To compare the distribution of storage proteins in low-glutelin rice seed with that in other cultivars having normal protein compositions, immunofluorescence labeling with specific antibodies was applied to visualize the distribution of storage proteins in endosperm tissues. The endosperm tissues from five cultivars were reacted with anti-prolamin and anti-glutelin antibodies, and then observed by light microscopy and confocal laser scanning microscopy (CLSM). In low-glutelin rice, using microscopic analysis, a large proportion of storage proteins was observed in the endosperm tissue of 70% polished rice. To determine the localization of two types of protein bodies in endosperm tissues, images of the distribution of the type I protein body (PB-I) and the type II protein body (PB-II) were obtained by CLSM. The CLSM images showed that, in low-glutelin rice, prolamin which accumulates in PB-I remains in the center of 70% polished rice grains despite the elimination of 30% of the outer layer of brown rice grains. However, the other cultivars mostly contained glutelin which accumulates in PB-II and is distributed throughout the endosperm tissues. This shows that low-glutelin rice differs from the other cultivars not only in the major storage protein composition but also in the distribution of storage proteins in endosperm tissues. 相似文献