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91.
Hiromasa Kurosaki Rakesh K Sharma Masami Otsuka Masafumi Goto 《Analytical sciences》2003,19(4):647-648
The structure of 7,8-dihydroxy-4-methylcoumarin was determined by an X-ray diffraction method. The compound crystallized in the triclinic space group P1, Z = 2, with a = 7.631(2), b = 9.456(5), c = 7.075(3)A, alpha = 103.13(3), beta = 91.84(3), gamma= 68.21(3) degrees, and V= 460.9(3)A3. The X-ray crystal structure was also compared with those of 5,7-dihydroxy-4-methylcoumarin and 7-hydroxy-4-methylcoumarin. 相似文献
92.
The influence of a static magnetic field on the instability of plastic flow (the Portevin-Le Chatelier effect) is revealed in NaCl: Eu quenched crystals. It is found that, in an external magnetic field, the yield stress of the crystals is reduced, the probability of plastic strain jumps and their amplitude decrease, and the amplitude distribution of the plastic strain jumps becomes random. The number of shear bands formed on the surface of crystals strained in the magnetic field is halved as compared to that observed without a magnetic field. 相似文献
93.
Y. G. Zhu Z. Q. Li D. Zhang T. Tanimoto 《Journal of Polymer Science.Polymer Physics》2006,44(8):1161-1167
The mixed powders of poly(ethylene terephthalate) (PET) and SiO2 has been subjected to cryomilling. The evolution of microstructure with time was characterized using scanning electron microscope, transmission electron microscope, field emission scanning electron microscope, and laser diffraction particle size analyzer. It was shown that, upon cryomilling for 10 h, SiO2 nano particles were well deconglomerated into single particles (~30 nm) that get homogeneously dispersed in PET matrix. The resulted PET/SiO2 primary particles were flake‐shaped with a size of 400 nm. These primary composite particles agglomerated to form secondary composite particles with an average size about 7.6 μm. A three‐stage model was purposed for the formation mechanism of the nanocomposite structures induced by cryomilling. Our evidences suggest that cryomilling is a capable and promising technique for the production of polymer/inorganic nanocomposites. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1161–1167, 2006 相似文献
94.
O6-Methylguanosine derivative was treated with sodium nitrite or isoamylnitrite in the presence of carboxylic acid to give the purin-2-yl carboxylate, an unusual product bearing a carboxylic group at the 2-position of the purine moiety. 相似文献
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Shibukawa Masami Saito Masanori Kuroda Rokuro 《Analytical and bioanalytical chemistry》1984,319(4):410-414
Analytical and Bioanalytical Chemistry - The size-exclusion chromatographic behaviour of 8-hydroxyquinoline (abbreviated as HOx) and its metal(II, III) chelates on Fractogel PVA 2000 in p-dioxane... 相似文献
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