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141.
Low-velocity pneumatic conveying in horizontal pipe for coarse particles and fine powders 总被引:3,自引:0,他引:3
First,the characteristics of low-velocity conveying of particles having different hardness are experimentally investigated in a horizontal pipeline in terms of flow pattern and pressure drop to show that the slug flow can be classified into two types depending on the settling of particles along the pipeline,and the period is small for slug flow without the settled layer,which is called solitary slug flow.The pressure drop for soft particles is shown to be larger than that for hard particles.Then,experimental results are presented on horizontal fluidized-bed conveying of fine powders to show that air release from the top surface of the conveying channel is an important factor for high mass flow rate of particles. 相似文献
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Yoichi Tanaka Yuji Taniguchi Daisaku Tanaka Masatoshi Toyoda Hideshi Ishii Teruo Tanabe Yasuko Terada Shinjiro Hayakawa Jun Kawai 《Analytical sciences》2005,21(7):839-843
The Kosa (yellow sand) aerosol affects the global environment as well as human health because it migrates from the interior of China to other areas, absorbing various atmospheric elements. Investigation into individual Kosa aerosol particles, which are submicroscopic to several tens of micrometers in diameter, is required to resolving the issue. We installed a scanning electron microscope (SEM) equipped with an energy dispersive X-ray spectrometer (EDX) on a synchrotron radiation (SR) beam line and introduced the SR beam into the SEM chamber for combinatorial application of SEM-EDX and SR X-ray fluorescence (SR-XRF) spectrometry to individual particles. It should be noted that detailed topographic observation by SEM and sensitive elemental analysis by SR-XRF, both crucial for individual particle measurement but which previously had to be carried out separately, were jointly performed inside the SEM chamber in this setup. Here, we show that SR-XRF results, in conjunction with SEM images, contributed toward resolving individual particle dispositions. Atmospheric sulfur primarily adheres to calcium in the aerosol particles and the particle surface roughens as a consequence of the chemical reaction between the two elements. 相似文献
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Masafumi Yano Yorichika Okino Yuji Ichihara Masakazu Tatsumi Munetaka Oyama Kazunobu Sato Takeji Takui 《Polyhedron》2009,28(9-10):1764-1767
Three highly π-extended tetraaryl-1,3-phenylenediamines for charged high-spin molecular systems were successfully synthesized using Suzuki coupling. Their electrochemical and spectroscopic properties were also examined. They showed blue fluorescence. The dications derived from highly π-extended tetraaryl-1,3-phenylenediamines were generated and characterized by electron transfer stopped-flow method. 相似文献
147.
Takeshi Ishikawa Yuji Mochizuki Shinji Amari Tatsuya Nakano Shigenori Tanaka Kiyoshi Tanaka 《Chemical physics letters》2008,463(1-3):189-194
We have developed a method named ‘fragment interaction analysis based on local MP2’ (abbreviated as FILM). This method enables us to decompose the interaction energy associated with dispersion interactions into contributions of localized occupied orbitals. In this study, the basis set dependence of the results derived from FILM was examined. The results suggested that the individual ratio of pair correlation energies of selected orbital pairs to the total dispersion interaction was almost independent of the basis set size. As an illustrative example, detailed analysis was performed on the human immunodeficiency virus type 1 protease complexed with lopinavir molecule. 相似文献
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Kentaro Okuma Jun-ichi Sakata Yuji Tachibana Takumi Honda Hiroshi Ohta 《Tetrahedron letters》1987,28(52):6649-6652
Wittig reagents were successfully changed to symmetrical olefins when treated with elemental selenium. The reaction proceeds through a selenocarbonyl intermediate, which existence was confirmed by Diels-Alder reaction. 相似文献
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Ming Zhao Yuji Wang Caixia Huo Chunyu Li Xiaoyi Zhang Li Peng Shiqi Peng 《Tetrahedron: Asymmetry》2009,20(2):247-258
In lead detoxification, the α-anomer of N-glycocyl-l-amino acid is more potent than its β-anomer. Here a six-step-reaction route for stereoselectively preparing N-(α-l-arabinose-1-yl)-l-amino acids is reported. Treating l-arabinose with acetic anhydride and sodium acetate provided 1,2,3,5-tetra-O-acetyl-l-arabinofuranose in 90% yield. After removing the 1-acetyl group, the thus formed 2,3,5-tri-O-acetyl-l-arabinofuranose and N-(2-nitrophenylsulfonyl)-l-amino acid t-butylesters were treated with triphenylphosphine to perform Mitsunobu dehydration and form 2,3,5-tri-O-acetyl-l-arabinofuranosyl-l-[N-(2-nitrophenylsulfonyl)]amino acid t-butylesters 2a–f, and the ratios of their α- to β-anomer ranged from 8/1 to 9/1. Chromatographic separation provided epimerically pure 2a–f-α and 2a–f-β. In the presence of CF3CO2H, 2a–f-α and 2a–f-β were converted to α- and β-anomers of N-(2,3,5-tri-O-acetyl-l-arabinofuranosyl)-N-(2-nitrobenzenesulfonyl)-l-amino acids, 3a–f-α and 3a–f-β, in 87–92% yields. While in the presence of NaOCH3, 3a–f-α and 3a–f-β were converted to α- and β-anomers of N-(l-arabinofuranosyl)-N-(2-nitrobenzenesulfonyl)-l-amino acids, 4a–f-α and 4a–f-β, in 90–96% yields. Treating 4a–f-α and 4a–f-β with N-ethyldiisopropylamine (DIPEA) and thiophenol, their 2-nitrophenylsulfonyl groups were removed, and the α- and β-anomers of N-(l-arabinose-1-yl)-l-amino acids were formed in 70–79% yields. The bioassay confirmed that the lead detoxification activity of the α-anomer was significantly higher than that of the β-anomer. 相似文献