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91.
Jun Xiang Ge 《International Journal of Infrared and Millimeter Waves》1994,15(10):1681-1688
In 1991, we developed a new type of quasi-optical power combiner, called a compound quasi-optical power combiner, at Ka-band. In this paper, the circuit of such a compound quasi-optical power combiner is analysed. Its equivalent circuit model is proposed. The circuit equations, the balance condition, the injection locking and the stabilized condition of the compound quasi-optical power combiner are studed by the equivalent circuit model. As an example, a compound quasi-optical power combiner which consists of two single—cavity, two—device power combiners is analysed 相似文献
92.
R. Szymczak K. Zaveta H. Szymczak H. -Q. Guo H. Kronmü ller 《Journal of magnetism and magnetic materials》1994,130(1-3):363-366
The temperature dependence of magnetization of a nanocrystalline Fe60Co30Zr10 alloy annealed at various temperatures to varying crystal sizes was investigated down to 5 K in the field range up to 5 T. The fitting procedure gave T3/2 as the leading term irrespective of the crystal size. We suggest that the increase of the coefficient by this term for smaller crystals may be connected to an increased relative volume of their surface. 相似文献
93.
94.
Xia Yin Weiguang Zhang Qijiao Zhang Jun Fan Chian Sing Lai Edward R. T. Tiekink 《应用有机金属化学》2004,18(3):139-140
The centrosymmetric structure of {Cd[S2CN(CH2Ph)2]2}2 features both bridging and chelating dithiocarbamate ligands so that a square pyramidal S5 coordination geometry results. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
95.
饮食中微量元素砷的分布规律与人体健康关系 总被引:3,自引:1,他引:2
采用催化动力学光度法测定了六大类(共三十种)样品中的总砷含量,探讨了砷在食品中的分布规律,建立了砷在人体中的安全系效和积累系效的效学评价公式,用于评价砷与人体健康的关系,这对人们选择食物有一定的指导意义。 相似文献
96.
97.
Qixin Guo Mitsuhiro NishioHiroshi Ogawa Akira Yoshida 《Solid State Communications》2003,126(11):601-604
Temperature dependence of optical reflectance spectra in vacuum ultraviolet region for aluminum nitride has been measured on high-quality single crystal with synchrotron radiation. The dominant structure due to the interband transition is observed at photon energy around 7.7 eV. With decreasing temperature, the energy position of the dominant structure in the reflectance spectra shifts towards higher energy. The experimental data has been fitted to the Bose-Einstein expression and the obtained parameter related to the strength of the electron-phonon interactions is much smaller than that for the peak at 6.2 eV, suggesting that the higher-lying interband transition energy decreases more slowly with increasing temperature in aluminum nitride (AlN). 相似文献
98.
A polymerized quaternary ammonium salt polydiallyldimethylammonium chloride, exhibiting high stability to heat and base, was prepared and applied as phase-transfer catalyst (PTC) in halogen-exchange (Halex) fluorination of chloronitrobenzenes to give excellent yields of corresponding fluoronitrobenzenes. Dimethyl sulfoxide was found to be the best solvent when microwave was applied as heating resource. 相似文献
99.
Jun Jiao Lifeng Dong Sean Foxley Catherine L Mosher David W Tuggle 《Microscopy and microanalysis》2003,9(6):516-521
In this article, we report a technique for growing carbon nanotubes in a more controllable fashion, which enables us to synthesize nanotubes directly in various forms of designed patterns. This nanofabrication process is based on a combination of focused ion beam (FIB) and chemical vapor deposition (CVD) techniques. In this process, arrays of conductive patterns were first deposited on silicon substrates by directing a gaseous compound (C(9)H(16)Pt) via the capillary needle-sized nozzles within a FIB system. The substrates were then coated with catalyst and further modified by the FIB to localize the position of the catalyst. Finally, the growth of carbon nanotubes on the designed substrates was carried out by CVD of hydrocarbon gases. This fabrication technique has the advantage of positioning carbon nanotubes in selected locations. This may open up opportunities for the direct synthesis of carbon nanotubes onto almost any substrate material, thus allowing fabrication of carbon nanotube-based devices. 相似文献
100.
Y. Gu Igor L. Kuskovsky R.D. Robinson G.F. Neumark S.P. Guo M.C. Tamargo 《Solid State Communications》2005,134(10):677-681
The composition and size of optically active CdxZn1−xSe/ZnSe quantum dots are estimated with a previously developed method. The results are then compared with those obtained for CdxZn1−xSe/Zn0.97Be0.03Se QDs. We show that introducing Be into the barrier material enhances both Cd composition and quantum size effect of optically active quantum dots. 相似文献