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排序方式: 共有215条查询结果,搜索用时 15 毫秒
31.
32.
Optical crossbar switches were fabricated using multiwavelength vertical-cavity surface-emitting lasers and free-space microoptics. Four-channel optical switches with 10-nm wavelength intervals were successfully demonstrated. 相似文献
33.
S. Suga M. Taniguchi M. Seki H. Sakamoto H. Kanzaki M. Yamamoto A. Kurita Y. Kaneko T. Koda 《Solid State Communications》1984,49(11):1005-1008
Ultraviolet photoemission (UPS) and inner core reflectance spectra have been measured on SmSe(100) surface with synchrotron radiation. Besides the multiplet structures observed in UPS spectra for the Sm 4f, 5p and 5s excitations, the reflectance spectrum has revealed a multiplet structure associated with the Sm 4d→4f excitation. Each band of the UPS spectra has shown remarkably different hν dependence and the resonant behavior of the cross section. Sm 4f- and Se 4p-derived valence band features are unambiguously identified by the angle resolved UPS. 相似文献
34.
The scope of microwave-assisted coupling reaction of alkynylstibane and aryl iodides to form diarylalkynes is presented. Highly efficient reaction took place smoothly in dimethyl sulfoxide in the presence of cetyltrimethylammonium bromide with much shorter time (1 min) and lower catalyst loading (0.5 mol%) than the conventional method (heating for 24 h with 10 mol% catalyst). 相似文献
35.
Kimata M Terashima T Kurita N Satsukawa H Harada A Kodama K Sato A Imai M Kihou K Lee CH Kito H Eisaki H Iyo A Saito T Fukazawa H Kohori Y Harima H Uji S 《Physical review letters》2010,105(24):246403
We report the results of the angular-dependent magnetoresistance oscillations (AMROs), which can determine the shape of bulk Fermi surfaces (FSs) in quasi-two-dimensional (Q2D) systems, in a highly hole-doped Fe-based superconductor KFe2As2 with Tc ≈ 3.7 K. From the AMROs, we determined the two Q2D FSs with rounded-square cross sections, correspond to 12% and 17% of the first Brillouin zone. The rounded-squared shape of the FS cross section is also confirmed by the analyses of the interlayer transport under in-plane fields. From the obtained FS shape, we infer the character of the 3d orbitals that contribute to the FSs. 相似文献
36.
K. Kurita S. Miyazawa M. Asukabe E. Wada 《Journal of Macromolecular Science: Physics》2013,52(3):375-388
Abstract A new type of time-dependent and strain-history-dependent viscoelasticity was discovered in semidilute polymer solutions. Dynamic moduli G′ and G″ of 20% and 10% nitrile butadiene rubber (NBR) solutions were recorded as a function of time while oscillatory shear deformations were maintained. The moduli decrease with time was observed only at lower frequencies. The time dependence of G′ was more pronounced than that of G″. At a higher temperature, the time dependence was extended toward higher frequencies also, and the time dependence became stronger. Lowering the concentration of solution gave a similar effect as increasing temperature. After the cessation of oscillations, a slow recovery was observed. The recovery was somewhat faster at the higher temperature. The time-dependent moduli and their recovery were explained by the change and recovery of structures associated with long branches and gels in the NBR. The structure change occurred at higher frequencies also, but it was not observed during the application of oscillation. Only in subsequent measurements at lower frequencies could the structure change be detected. Thus, the change may be regarded as strain history dependent. The mechanism of the structural change was explained with either the entanglement or osmotic pressure models, depending on concentration. 相似文献
37.
S. Ota S. Shimoura H. Iwasaki M. Kurokawa S. Michimasa N. Aoi H. Baba K. Demichi Z. Elekes T. Fukuchi T. Gomi S. Kanno S. Kubono K. Kurita H. Hasegawa E. Ideguchi N. Iwasa Y.U. Matsuyama K.L. Yurkewicz T. Minemura T. Motobayashi T. Murakami M. Notani A. Odahara A. Saito H. Sakurai E. Takeshita S. Takeuchi M. Tamaki T. Teranishi Y. Yanagisawa K. Yamada M. Ishihara 《Physics letters. [Part B]》2008
38.
Ryuichi Wada Tomoki Nakayama Tetsuya Hiyama Yasushi Fujiyoshi Naoyuki Kurita 《Isotopes in environmental and health studies》2017,53(6):646-659
Isotope ratios of carbon dioxide and water vapour in the near-surface air were continuously measured for one month in an urban area of the city of Nagoya in central Japan in September 2010 using laser spectroscopic techniques. During the passages of a typhoon and a stationary front in the observation period, remarkable changes in the isotope ratios of CO2 and water vapour were observed. The isotope ratios of both CO2 and water vapour decreased during the typhoon passage. The decreases can be attributed to the air coming from an industrial area and the rainout effects of the typhoon, respectively. During the passage of the stationary front, δ13C–CO2 and δ18O–CO2 increased, while δ2H–H2Ov and δ18O–H2Ov decreased. These changes can be attributed to the air coming from rural areas and the air surrounding the observational site changing from a subtropical air mass to a subpolar air mass during the passage of the stationary front. A clear relationship was observed between the isotopic CO2 and water vapour and the meteorological phenomena. Therefore, isotopic information of CO2 and H2Ov could be used as a tracer of meteorological information. 相似文献
39.
The phenomenon of the diffusion of proton and deuteron in a single crystal of magnesium aluminate spinel was studied by infrared
absorption. The chemical diffusion coefficient of proton was determined by the relaxation time of the absorption intensity
upon the substitution of deuteron with proton. The temperature dependence of the chemical diffusion coefficient of proton
for was expressed as . The chemical diffusion coefficient of proton was found to be independent of the composition of spinel and of the atmosphere.
Paper presented at the 11th Euro Conference on the Science and Technology of Ionics, Batz-sur-Mer, Sept. 9–15 2007. 相似文献
40.
A simple copper- and base-free palladium-catalyzed Sonogashira-type cross-coupling by the use of triarylantimony dicarboxylates is described. Reaction of triarylantimony diacetates with terminal alkynes in the presence of 1 mol % of PdCl2(PPh3)2 catalyst led to the formation of cross-coupling products in good to excellent yields. The reaction proceeded effectively under an aerobic condition, in that two of the three aryl groups on antimony could be transferred to the coupling products, whereas only one of them was involved in the reaction in an argon atmosphere. The reaction is sensitive to the electronic nature of the diacetates, and those bearing an electron-withdrawing group on the aromatic ring showed higher reactivity than those having an electron-donating group. 相似文献