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101.
ZrO2 nanoparticles was uniformly co-deposited into a nickel matrix by electroplating of nickel from a Watts bath containing particles in suspension which were monodispersed with dispersant under DC electrodeposition condition. It was found that morphology, orientation and hardness of the nanocomposite coatings with monodispersed ZrO2 nanoparticles had lots of difference from the nanocomposite coatings with agglomerated ZrO2 nanoparticles and pure nickel coatings. Especially, the result of hardness showed that only a very low volume percent (less than 1 wt.%) of monodispered ZrO2 nanoparticles in Ni-ZrO2 nanocomposite coatings would result in higher hardness of the coatings. The hardness of Ni-ZrO2 nanocomposite coatings with monodispersed and agglomerated ZrO2 nanoparticles were 529 and 393 HV, respectively. The hardness value of the former composite coatings was over 1.3 times higher than that of the later. All these composite coatings were two-three times higher than that of pure nickel plating (207 HV) prepared under the same condition. The strengthening mechanisms of the Ni-ZrO2 nanocomposite coatings based on a combination of grain refinement strengthening from nickel matrix grain refining and dispersion strengthening from dispersion state of ZrO2 nanoparticles in the coatings. 相似文献
102.
Tao Jin Feng-Xian Jiang Xiao-Li Li Fang Wang Xiao-Hua Shen Rui-Qiang Zhang Hai-Shun Wu 《Applied Surface Science》2006,253(5):2708-2712
CoPt/Ag and [C/CoPt]n/Ag thin films have been prepared onto the glass substrates by magnetron sputtering. We investigated the evolution of texture and magnetic properties of CoPt/Ag and [C/CoPt]n/Ag films. The results show that C-doping plays an important role in improving (0 0 1) texture, improving the order parameter S, reducing the intergrain interactions, and making the magnetization reversal mechanism more close to Stoner-Wolfarth rotational mechanism. The growth mechanism of (0 0 1) texture also seems to be related strongly to the films thickness. Our results show that the highly (0 0 1)-oriented films with ordered fct phase have a significant potential for the perpendicular media of extremely high-density recording. 相似文献
103.
The behavior of a two-level entangled atom in an optical field with circular polarization is studied in this paper. The interaction of an optical field and one of the entangled atoms is analyzed in detail. A general solution of the SchrAo¨Gdinger equation about the motion of the entangled atom is obtained. The properties of the action are dependent on the initial state of the atom. By detecting the entangled atom out of the field, we can obtain the state of the other atom moving in the field. It is shown that the state of the atom out of the field will influence the energies of the split-levels of the atom in the field. 相似文献
104.
105.
106.
利用Ditzian-Totik光滑模,研究了推广的Kantorovich算子在Ba空间中的逼近,得到逼近的正定理与等价定理.所得结果改进、推广和统一了一些作者的结果. 相似文献
107.
108.
Jiaqiang Wang Hua Fang Ying Li Junjie Li Zhiying Yan 《Journal of molecular catalysis. A, Chemical》2006,250(1-2):75-79
Cobalt-doped mesoporous titania with a crystalline framework synthesized by surfactant templating method presented highly selective (99%) and reasonable conversion rate (49%) of catalytic oxidation of para-chlorotoluene to para-chlorobenzaldehyde in acetic acid using aqueous hydrogen peroxide as oxidant for the first time. Recycling of the catalyst indicates that the catalyst can be used a number of times without losing its activity to a greater extent. By contrast, cobalt-doped mesoporous titania without a crystalline structure and cobalt doped the commercial titania, Degussa P25 prepared by impregnation method with the similar concentration of cobalt were found inactive. The effects of catalyst concentration, reaction time, reaction temperature, and solvents on the performance of the catalyst were also investigated. 相似文献
109.
Xiao-Hong Xu Xiao-Li Li Fang Wang Feng-Xian Jiang Hai-Shun Wu 《Applied Surface Science》2006,252(8):2910-2914
FexPt100−x(30 nm) and [FexPt100−x(3 nm)/ZrO2]10 (x = 37, 48, 57, 63, 69) films with different ZrO2 content were prepared by RF magnetron sputtering technique, then were annealed at 550 °C for 30 min. This work investigates the effect of ZrO2 doping on the microstructural evolution, magnetic properties, grain size, as well as the ordering kinetics of FePt alloy films. The as-deposited films behaved a disordered state, and the ordered L10 structure was obtained by post-annealing. The magnetic properties of the films are changed from soft magnetism to hard magnetism after annealing. The variation of the largest coercivities of [FexPt100−x/ZrO2]10 films with the Fe atomic percentage, x and differing amounts of ZrO2 content reveals that as we increase the ZrO2 content we must correspondingly increase the amount of Fe. This phenomenon suggests that the Zr or O atoms of ZrO2 preferentially react with the Fe atoms of FePt alloy to form compounds. In addition, introducing the nonmagnetic ZrO2 can reduce the intergrain exchange interactions of the FePt/ZrO2 films, and the interactions are decreased as the ZrO2 content increases, the dipole interactions are observed in FePt/ZrO2 films as the ZrO2 content is more than 15%. 相似文献
110.
On the third largest Laplacian eigenvalue of a graph 总被引:1,自引:0,他引:1
Ji-Ming Guo 《Linear and Multilinear Algebra》2007,55(1):93-102
In this article, a sharp lower bound for the third largest Laplacian eigenvalue of a graph is given in terms of the third largest degree of the graph. 相似文献