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排序方式: 共有248条查询结果,搜索用时 31 毫秒
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Y. Oura S. Enomoto H. Nakahara H. Matsue C. Yonezawa 《Journal of Radioanalytical and Nuclear Chemistry》2000,244(2):311-315
Prompt -ray analysis with the internal monostandard method was used to organs taken from rats. After B or Cd was administered, the B/H and Cd/H contents ratios were determined in the brain, kidney, and liver to study their distribution and metabolism. Boron was distributed in all organs but metabolized quickly. Cd was slowly accumulated in the liver and kidneys during the 65 hours studied but no Cd was detected in the brain. 相似文献
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H. Yonezawa C. Yonezawa T. Shigematsu 《Journal of Radioanalytical and Nuclear Chemistry》1995,198(1):125-134
Instrumental charged particle activation analysis (CPAA) for determining boron in a thin surface layer of silicon was developed. The nuclear reaction and incident energy were selected in order to minimize any interference from surface or bulk impurities. Thin boron film was used as a standard sample and its boron content was determined by neutron induced prompt -ray analysis. As a result, we were able to determine11B and10B at 1015 atoms/cm2 with an accuracy of better than 3% by 4 MeV proton and 7 MeV -bombardment, respectively. Each boron isotope could be determined down to 1013 atoms/cm2. Our CPAA was applied to determine boron in a boron implanted silicon wafer of a SIMS standard sample. 相似文献
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C. Yonezawa M. Magara H. Sawahata M. Hoshi Y. Ito E. Tachikawa 《Journal of Radioanalytical and Nuclear Chemistry》1995,196(1):171-178
The extraction behavior of uranium(VI), plutonium(IV) and some fission products like zirconium(IV), ruthenium(III) and europium(III) from 3.5M nitric acid with -irradiated organic phase pre-equilibratedn-dodecane solutions of dihexyl derivatives of hexanamide (DHHA), octanamide (DHOA) and decanamide (DHDA) has been investigated as a function of absorbed dose upto 184·104 Gy. The results indicate that the extraction of uranium(VI) decreases gradually with dose upto 72·104 Gy and becomes almost constant thereafter, while, the extraction of plutonium(IV) decreases upto a dose of 20·104 Gy and then increases rapidly up to a dose of 82·104 Gy indicating synergistic effects of radiolytic products formed at higher doses. Extraction of zirconium(IV) increases gradually upto a dose of 72·104 Gy. Europium(III) does not get extracted with any of these amides in the entire dose range (0–184·104 Gy) studied, however, ruthenium shows insignificant increase in extraction with dose. The decrease inD values noticed in the case of plutonium and zirconium after the dose of 72·104 Gy which was attributed to the third phase formation and emulsification. Infrared studies confirm the final products of radiolysis as the respective amines and carboxylic acids. The degraded amide contents have been estimated by quantitative IR spectrophotometric technique. Extraction data obtained for uranium(VI) and plutonium(IV) with TBP/n-dodecane system have also been compared under similar experimental conditions. 相似文献
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Masaki Hasegawa Kazuhiko Saigo Hirokazu Katsuki Noriyuki Yonezawa Toshio Kanoe 《Journal of polymer science. Part A, Polymer chemistry》1983,21(8):2345-2362
The ring-opening polyaddition reaction of anti and syn head-to-head Coumarin dimers with diamines and the photocleavage behavior of the resulting polyamides were investigated. Anti head-to-head Coumarin dimer successfully reacted with aliphatic and aromatic diamines in an aprotic polar solvent to give corresponding high molecular weight polyamides. The polyamides showed good film forming ability and exhibited solubility behavior typical of polyelectrolytes. Furthermore, these polyamides were found to undergo exclusively asymmetric photocleavage on the cyclobutane rings in the polymer main chain to give a fumaramide unit with elimination of 2,2′-dihydroxystilbene. On the other hand, syn head-to-head Coumarin dimer gave only low molecular weight polyamides. These polymerization and photocleavage behaviors were elucidated in comparison with those of model reactions. 相似文献
6.
Susumu Yonezawa Shiori Nishibu Masayuki Takashima 《Journal of fluorine chemistry》2007,128(4):438-447
The preparation of the rare earth containing oxide fluoride glasses LnF3 (Ln; Y through Lu)-BaF2-AlF3-GeO2 in which the nominal content of LnF3 reached 60 mol% in maximum and their basic properties such as density, refractive index and glass transition temperature were investigated and summarized in detail. Especially, in order to discuss the local structure around the rare earth ion in the glass, the Judd-Ofelt analysis (discussion with Ω parameters) of the HoF3-BaF2-AlF3-GeO2 glasses was carried out. The unique fluorescent behavior and the magnetic properties of LnF3-BaF2-AlF3-GeO2 glasses (Ln = Tb and/or Sm) were also studied. 相似文献
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A new force approach is reported in which we improve the wavefunction so that the Hellmann-Feynman theorem is satisfied. A sufficient condition for the Hellmann-Feynman theorem to be satisfied is that the basis set includes AO derivatives ?xr/?xrfor any basis xr. Here we test a procedure in which only the first derivative AOs are added to the “parent” AOs. The results are very encouraging. 相似文献