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排序方式: 共有626条查询结果,搜索用时 750 毫秒
51.
Yusuke Takeuchi Fangming Jin Kazuyuki Tohji Heiji Enomoto 《Journal of Materials Science》2008,43(7):2472-2475
Acidic hydrothermal degradation of glucose was examined in the presence of HCl, H2SO4, and H3PO4 with pH varying from 1.5 to 2.5 and reaction time varying from 1 to 10 min at 523 K, to investigate the effect of different
acid catalysts and acid concentration on the production of 5-hydroxymethyl-2-furaldehyde (HMF) and levulinic acid from glucose.
At lower acidities of pH 2.5, a considerably higher amount of HMF was produced. The increase in acid concentration accelerated
the conversion of HMF to levulinic acid. The order for the production of HMF using the three acids is in the sequence of H3PO4 > H2SO4 > HCl. On the contrary, the order for production of levulinic acid follows HCl > H2SO4 > H3PO4. In the experimental conditions used in this study, the highest yield of levulinic acid is about 55%, which was obtained
at pH 1.5 for 5 min in the case of HCl as an acid catalyst, and the total highest yields of HMF and levulinic acid are about
50%, which occurred at pH 2.0 for 5 min in the case of H3PO4 as an acid catalyst. 相似文献
52.
53.
54.
Kenji Shiota Masaki Takaoka Shuji Yamaguchi Kazuyuki Oshita 《Drying Technology》2015,33(11):1286-1294
Because fine particulate matter ≤2.5 µm in diameter (PM2.5) causes health problems, PM2.5 emissions are of concern. However, little research on stationary sources has been conducted. To determine the concentration and filtration behavior of PM2.5, dust was collected from five fluid-bed sewage sludge incinerators (SSIs) sorted by particle size using cascade impactors. The average PM2.5 concentration was 0.00014–4.8 mg/Nm3. The total estimated amount of PM2.5 emissions from the SSIs for all plants in Japan was 0.96–8.9 tons/year. Since the SSIs with dry Electrostatic Precipitators (EP) contributed 75–99% of the total emissions, replacing dry EPs with bag filters would significantly reduce the PM2.5 emissions from SSI. 相似文献
55.
Yuichi Shimauchi Sachiko Ode Tsutomu Yamazaki Yuta Matsushima Kazuyuki Maeda 《Journal of Porous Materials》2010,17(3):305-312
A new vapor phase transport (VPT) technique to prepare an inverse silica replica of an ordered mesoporous carbon was developed.
Tetraethyl orthosilicate (TEOS) was infiltrated in mesoporous carbon CMK-3 as the hard template at 180 °C for 48 h under an
autogenous pressure in an autoclave in the presence of water. The samples obtained by removal of CMK-3 retained structural
regularity of CMK-3 with little shrinkage of framework, which were characterized by SAXRD, N2 adsorption, TG-DTA, and SEM. Influence of preparation temperature on the loading amount of silica was investigated. The multi-step
replication process was monitored by characterizing the replicated materials as well as intermediate composites. 相似文献
56.
Effects of rice straw returning methods on N<Subscript>2</Subscript>O emission during wheat-growing season 总被引:1,自引:0,他引:1
Erdeng Ma Guangbin Zhang Jing Ma Hua Xu Zucong Cai Kazuyuki Yagi 《Nutrient Cycling in Agroecosystems》2010,88(3):463-469
A field experiment was conducted in Jurong of Nanjing, Jiangsu Province, China from 2006 to 2008 to investigate N2O emission during the wheat-growing season as affected by various rice straw returning methods prior to wheat cultivation.
The study was designed to have four treatments: no rice straw applied (CK), rice straw burnt in situ (RB), rice straw evenly
incorporated into the topsoil (RI), rice straw evenly spread over the field as mulch (RM). Results showed that N2O emission was decreased by 24–29% in Treatment RB and by 3–18% in Treatment RI, but increased by 15–39% in Treatment RM,
compared with that in Treatment CK. The contents of soil total C and N at wheat harvest were significantly increased by 7–13%
and by 8–12% in Treatment RI, respectively, compared with that in Treatment CK. The wheat grain yield in Treatment RI was
1.0–1.2 times that in the Treatment CK. Based on these results, the best management practice of returning rice straw to the
soil prior to wheat cultivation is evenly incorporating rice straw into the topsoil, as the method tended to reduce N2O emission during the wheat-growing season and increase wheat yield and soil fertility. 相似文献
57.
Minoru Mochihara Kazuyuki Hokamoto Masahiro Fujita 《Metals and Materials International》1998,4(4):911-914
A shearing process of a metal plate by an impulsive pressure generated by underwater explosion was numerically simulated, and the analytical result was compared with some experimental results. The features of the deformation and the shearing process were discussed by considering the fracture condition. 相似文献
58.
Takakuni Douseki Takeshi Yamada Junzo Yamada Kazuyuki Ito Kazuo Nishi 《Solar Energy Materials & Solar Cells》2001,67(1-4)
We have developed a mobile global positioning system (GPS) that operates on just photovoltaic (PV) cells. The system receives wireless signals from satellites and shows one's present location accurately on a map without the need for a battery. A PV display module, which combines a transparent LCD with a-Si PV cells and has a power generation function, is added to ordinary PV cells to increase the total amount of power generated. The PV display module enables 40% more power generation than a system without the module. 相似文献
59.
Takashi Funaki Masatoshi Yanagida Nobuko Onozawa-Komatsuzaki Yuji Kawanishi Kazuyuki Kasuga Hideki Sugihara 《Solar Energy Materials & Solar Cells》2009,93(6-7):729-732
Ruthenium(II) complexes by introducing phenylene–ethynylene subunit into a tpy (tpy=2,2′:6′,2″-terpyridine) ligand were newly synthesized, and their photophysical and photochemical properties were characterized. The molar extinction coefficients of these dyes were larger than that of black dye. The photovoltaic performances of the solar cells based on these synthesizing dyes were investigated under AM 1.5 irradiation (100 mW cm?2). The conversion efficiencies of 1a and 1b were 5.7% and 2.4%, respectively. 相似文献
60.
Atsushi Ohma Tetsuya Mashio Kazuyuki Sato Hiroshi Iden Yoshitaka Ono Kei Sakai Ken Akizuki Satoshi Takaichi Kazuhiko Shinohara 《Electrochimica acta》2011,(28):10832
The biggest issue that must be addressed in promoting widespread use of fuel cell vehicles (FCVs) is to reduce the cost of the fuel cell system. Especially, it is of vital importance to reduce platinum (Pt) loading of catalyst layers (CLs) in the membrane electrode assembly (MEA) of a proton exchange membrane fuel cell (PEMFC). In order to lower the Pt loading of the MEA, mass transport of reactants related to the performance in high current density should be enhanced significantly as well as kinetics of the catalyst, which can result in the better Pt utilization and effectiveness. In this study, we summarized our analytical approach and methods for reduction of Pt loading in CLs. Microstructure, mass transport properties of the reactants, and their relation in CLs were elucidated by applying experimental analyses and computational methods. A simple CL model for I–V performance prediction was then established, where experimentally elucidated parameters of the microstructure and the properties in CLs were taken into account. Finally, we revealed the impact of lowering the Pt loading on the transport properties, polarization, and the I–V performance. 相似文献