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81.
Because of package, a single FBG has dual Bragg wavelength. One is sensitive to stress and the other is sensitive to temperature. By using the special mechanism, the wavelengths can be tuned by stress and temperature respectively. 相似文献
82.
83.
Yingyu Hu Guoqiao Lai Yongjia Shen Yongfang Li 《Monatshefte für Chemie / Chemical Monthly》2004,33(2):1167-1172
Zinc(II) and magnesium(II) phthalocyanines bearing four substituted propylenedithiotetrathiafulvalene (PDT-TTF) units were synthesized and characterized by NMR, MS, EA, and UV/VIS spectra. The absorption peaks of two target molecules were hypsochromically shifted compared with the phthalocyanine parent compound. Studies using cyclic voltammetry indicated that introduction of Zn and Mg as central metals enhanced the electronwithdrawing between the phthalocyanine core and the PDT-TTF unit, thus losing one electron to form (PDT-TTF)+ becomes more difficult. 相似文献
84.
Hong-wei Zhang Shao-ying Zhang Bao-gen Shen Helmut Kronmüller 《Journal of magnetism and magnetic materials》2003,260(3):352-360
The magnetization behavior in nanocrystalline permanent magnets has been investigated using mean field Stoner–Wohlfarth model. The model is comparatively simple but allows the numerical treatment of extended nanostructures. The predominant intergrain exchange coupling is expressed by a mean field constant Nm in spite of no explicit relationship between Nm and the microstructure. By this model, the experimental phenomena, such as the remanence enhancement, the shape of demagnetization curve, the irreversible magnetization, the exchange bias field and their respective temperature dependence, can be well explained. The Nm dependence of magnetic properties has been extensively discussed in the present paper. 相似文献
85.
5‐Methylene‐2‐oxazolidinone (1) and 5‐methylene‐1,3‐thiazolidine‐2‐thione (4) react with various isocyanates to give the corresponding urethanes 3 and 5 in high yields in the presence of palladium(0) or palladium(II) catalyst under mild reaction conditions. A mechanism is proposed. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
86.
Spectral and Pseudospectral Approximations Using Hermite Functions: Application to the Dirac Equation 总被引:1,自引:0,他引:1
We consider in this paper spectral and pseudospectral approximations using Hermite functions for PDEs on the whole line. We first develop some basic approximation results associated with the projections and interpolations in the spaces spanned by Hermite functions. These results play important roles in the analysis of the related spectral and pseudospectral methods. We then consider, as an example of applications, spectral and pseudospectral approximations of the Dirac equation using Hermite functions. In particular, these schemes preserve the essential conservation property of the Dirac equation. We also present some numerical results which illustrate the effectiveness of these methods. 相似文献
87.
88.
Yu Zanping Zhou Zheyan School of Math.and Computer Science Fujian Normal University Fuzhou ) Shen Jianhe 《Annals of Differential Equations》2007,23(3):365-372
The paper aims to obtain existence and uniqueness of the solution as well as asymptotic estimate of the solution for singularly perturbed nonlinear third- order Robin boundary value problem with a turning point.In order to achieve this aim,existence and uniqueness of the solution for third-order nonlinear Robin boundary value problem is derived first based on the upper and lower solutions method under relatively weaker conditions.In this manner,the goal of this paper is gained by applying the existence and uniqueness results mentioned above. 相似文献
89.
用光栅衍射法测试液体表面张力 总被引:1,自引:0,他引:1
利用π型直线状振源,在待测液面产生正弦形表面驻波,将其作为一种理想的反射式光栅,通过对激光束的衍射,形成线阵衍射光斑.借助LCCD等硬件测试系统及相应的数据采集与处理系统,实时准确地测量液体表面张力。 相似文献
90.