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61.
The coherent quantum transport properties through the spin-polarized polyphenoxyl radical molecule have been investigated, using the density-functional-derived tight-binding model and the Green's functions method. The majority and minority spin components exhibit considerably different transmission spectra in the vicinity of the Fermi level. Namely, each spin component carries a different amount of current when the bias voltage is applied between the two electrodes that sandwich the polyradical molecule. Therefore, if the magnetization axis of the polyradical is fixed by the external magnetic field, and if the spin flip does not occur during the transmission, the assumed molecular bridge is expected to work as a spin filter or a spin valve. Furthermore, as long as the bias voltage is weak, the total spin current is observed to be larger than the current through its reduced molecular form. It indicates that the adsorption of some chemical species on the radical sites can be sensed by the change in conductance of the molecular bridge. 相似文献
62.
A residual oil sample prepared from a crude oil is chromatographed on a column having a molecular-weight exclusion limit at about 5000. Three-dimensional chromatograms (absorbance/wavelength/time) are recorded with a u.v.-visible rapid-scanning detector. The elution profiles of vanadium- or nickel-containing species are obtained by applying atomic absorption spectrophotometry to fractions of the column effluents. Both vanadium- and nickel-containing species are detected over the whole molecular-weight range available with the column. The elution profiles of vanadium and nickel differ; the major elution peak for vanadium appears at a slightly lower molecular-weight region of the chromatogram than that for nickel. By reference to the real-time recorded absorption spectra of the effluents, it is suggested that at least some of the metals are present as metalloporphyrins. 相似文献
63.
Toyoshima Atsushi Mitsukai Akina Tsukada Kazuaki Ooe Kazuhiro Haba Hiromitsu Komori Yukiko Murakami Masashi Kaneya Yusuke Sato Daisuke Asai Masato Sato Tetsuya K. Nagame Yuichiro 《Journal of Radioanalytical and Nuclear Chemistry》2018,317(1):421-430
Journal of Radioanalytical and Nuclear Chemistry - We have studied extraction behavior of group-6 elements Mo and W to search for suitable conditions for an on-line extraction experiment of their... 相似文献
64.
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66.
M. A. Tarasov E. A. Stepantsov M. Naito A. Tsukada D. Winkler A. S. Kalabukhov M. Yu. Kupriyanov 《Journal of Experimental and Theoretical Physics》2007,105(3):636-641
The possibility of preparing bicrystalline Josephson junctions and bolometers based on superconducting MgB2 on specially prepared bicrystalline MgO substrates is investigated. Microbridges 0.85–6.00 μm in width, intersecting the bicrystalline interface, are formed in epitaxial bicrystalline MgB2 films grown on these substrates. It is found that annealing of bicrystalline samples in oxygen leads to a systematic decrease in the critical current, an increase in the temperature width of the superconducting transition region, and to an improvement of the current-voltage (IV) characteristic, which becomes close in shape to the IV characteristic of a Josephson junction. The response of such a junction to radiation at a frequency of 110 GHz with an amplitude attaining 0.5 mV is measured. 相似文献
67.
The characteristics of electron transmission through C70 molecule bridge in which two atomic chain leads are connected to long-axis carbon atoms are investigated theoretically by
using tight-binding approach based on the Green’s function with only one π orbital electron per carbon atom. Electron transmission
through C70 molecule from the input to the output terminal is obtained. From the spectrum, the switching feature of the electron transmission
through C70 is found, and the oscillation property based on the quantized level is explained. The quantum current distributions inside
C70 molecule bridge are calculated and simulated by the quantum current density theory based on Fisher-Lee formula at the energy
point E = −0.2 eV, where the transmission spectrum shows a peak. The maximum and the minimum bond quantum currents are presented,
and the reason why the currents are distributed nonuniformly is explained by the phase difference of the atomic orbits. The
result shows that the currents at each atomic site agree with Kirchhoff quantum current conservation law.
Supported by the National Key Basic Research Development Project (Grant No. 2003CB716204), the International Corporation Project
of the Education Department of China (Grant No. 20050360563), the Key Laboratory of Advanced Photonic and Electronic Materials
of Jiangsu (Grant No. BM2003202) and the State Key Laboratory of Solid State Microstructures of Nanjing University 相似文献
68.
Martensitic transformation is the phase transformation accompanying orderly shear deformation without atomic diffusion. The structures made by martensitic transformation are classified as thin plate, lens or lath in steels. The mechanism by which the hierarchic microstructure in the lath martensite phase forms has heretofore not been understood. We have made clear the mechanism by considering, independently, two plastic deformations using the slip deformation model proposed by Khachaturyan, and present herein a deformation matrix for each of the six crystallographic variants in a packet of the hierarchic structure. Our results are quantitatively consistent with experimental results for the Kurdjumov–Sachs (K-S) crystal orientation relationship and habit plane. Furthermore, the important points of our study are as follows: the origin of the sub-block structure and the specific combination of the sub-block structure are clarified; the laths existing in a block can be explained; and deviations between the directional parallel and plane parallel are obtained quantitatively, without any adjustable parameters. 相似文献
69.
Murayama H Shimizu K Tsukada N Shimada A Kodama T Kitayama Y 《Chemical communications (Cambridge, England)》2002,(22):2678-2679
A significant effect of clay host was observed on the photocatalytic activity of TiO2; TiO2-pillared fluorine mica exhibited two orders of magnitude higher activity than TiO2 and TiO2-pillared montmorillonite for the photocatalytic degradation of gamma-HCH. 相似文献
70.
T. Maruyama D. Kaji T. Kaneko S. Goto K. Tsukada H. Haba M. Asai S. Ichikawa Y. Nagame H. Kudo 《Journal of Radioanalytical and Nuclear Chemistry》2003,255(2):253-256
Rapid chemical separation of berkelium is essential in order to measure the unknown isotope 252Bk. An anion exchange system of mineral acid and methanol was examined. An elution curve of Bk was obtained using 250Bk produced by the 248Cm+18O system and the 251Bk activity could be measured in the preliminary experiments. The whole chemical separation was completed within 30 minutes. 相似文献