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281.
282.
Y. Furukawa Y. Nishisaka K. Kumagai P. Kögerler F. Borsa 《Hyperfine Interactions》2007,176(1-3):65-68
The magnetic properties of an s?=?1/2 Heisenberg triangular antiferromagnet V15 have been studied by proton nuclear magnetic resonance (NMR) at very low temperature down to 100 mK using a He3-He4 dilution refrigerator. In total spin S T?=?3/2 ground state above 2.7 Tesla, proton spin-lattice relaxation rate (1/T1) shows thermally activated behavior as a function of temperature. On the other hand, a temperature independent behavior of 1/T1 at very low temperatures is observed in frustrated S T?=?1/2 ground state below 2.7 Tesla. Possible origins for the peculiar behavior of 1/T1 will be discussed in terms of magnetic fluctuations due to spin frustration. 相似文献
283.
K. Daoudi T. Tsuchiya T. Kumagai 《Applied Physics A: Materials Science & Processing》2007,88(4):639-642
Thin films of La0.7Ca0.3MnO3 were successfully grown epitaxially on (100) single-crystal SrTiO3 substrates by excimer-laser assisted metal-organic deposition. Initial amorphous LCMO thin films were obtained by metal-organic
deposition at 500 °C. Crystallization and epitaxial growth of the films was achieved using a KrF pulsed laser irradiation
while the film/substrate samples were kept at 500 °C. High resolution transmission electron microscopy observations on cross-sections
demonstrate the formation mechanism of the epitaxial films. The crystallization process starts at the LCMO/STO interface and
grows by increasing the number of laser shots. A fully crystallized film was obtained after 5 min of irradiation. The film/substrate
interface was found to be sharp and abrupt. The temperature dependence of the resistance R(T) shows various behaviors, starting
from insulating to semiconducting and metal–insulator transition material during the formation of the manganite film. The
oxygen content was also improved by increasing the irradiation time. Promising values of the temperature coefficient of resistance
were obtained from these manganite films for prospect integration in silicon based microbolometric devices.
PACS 81.15.-z; 81.15.Np; 73.61.-r; 71.30.+h 相似文献
284.
The crystal structure of isostructural SrCuV(2)O(7) and BaCuV(2)O(7) consists of one-dimensional (1D) zigzag chains of Cu atoms with next-nearest-neighbor interaction. The main intrachain interaction was found to be ferromagnetic and estimated at 4.6 K (Hamiltonian H approximately -2J). SrCuV(2)O(7) and BaCuV(2)O(7) are new examples in the scanty family of 1D ferromagnets. Isothermal magnetization measurements at 0.08 K and specific heat data showed that MCuV(2)O(7) exhibits antiferromagnetic long-range ordering at T(N) = 1.36 K for SrCuV(2)O(7) and T(N) = 1.47 K for BaCuV(2)O(7). Spin-flop transitions were observed in the antiferromagnetic state at 0.08 K near 0.5 kOe in SrCuV(2)O(7) and 2 kOe in BaCuV(2)O(7). In air, SrCuV(2)O(7) and BaCuV(2)O(7) melted incongruently above 983 and 1018 K, respectively. 相似文献
285.
Masanori Kumagai Naganori Ohisa Toshio Amano Nobuaki Ogawa 《Analytical sciences》2003,19(11):1553-1555
Near-infrared analysis (NIRA) was applied to discriminate and determine the cadmium content levels of unpolished rice using canonical discriminant analysis (CDA). The overall correct classification rate was 85.2% for 318 NIR spectra, repeated three times for 106 samples. After a further improvement through decreased misclassification rates, NIRA could be useful as a rapid, nondestructive and convenient analytical method for primary screening and detecting of cadmium-polluted rice. 相似文献
286.
Junzo Nokami Toshiyuki Yamamoto Mikio Kawada Mari Izumi Nobuko Ochi Rokuro Okawara 《Tetrahedron letters》1979,20(12):1047-1048
Malonic acid derivatives(gem-dicarboxylic acids) were converted to the corresponding ketones by the electrolysis. The reaction was employed for the synthesis of jasmones. 相似文献
287.
Tsutomu Kumagai Kazuya Murakami Hajime Hotta Toshio Mukai 《Tetrahedron letters》1982,23(45):4705-4708
Upon irradiation, 5-dicyanomethylenebicyclo[2.2.2]octene () gives a highly strained compound, 2,2-dicyanotricyclo[4.2.1.01,3]nonene () in good yield. Of additional interest is the observation that the starting material can be quantitatively regenerated from the photo-product with release of 28.8 kcal/mol. 相似文献
288.
Mikio Niimura 《Israel Journal of Mathematics》1980,37(4):327-330
In this note we obtain the relationships in the large between cluster sets, asymptotic values, exceptional values of meromorphic
functions on hyperbolic Riemann surfaces. Some of these are generalizations of the boundary theorems given by E. F. Collingwood
and M. L. Cartwright. 相似文献
289.
290.
It was found by the Michelson interferometric method that an absorption of 10.6 μm laser pulse generates an acoustic wave transverse to the direction of laser propagation in SF6. 相似文献