| 1. |
- Cao, X., et al.
(författare)
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Comparative studies on annealed proton exchange waveguides in Y-cut MgO : LiNbO3 and Z-cut LiNbO3
- 2004
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Ingår i: Wuli xuebao. - : Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences. - 1000-3290. ; 53:11, s. 3786-3793
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Tidskriftsartikel (refereegranskat)abstract
- Proton exchange waveguides in MgO:LiNbO.3 and LiNbO.3 crystals were fabricated , and the diffusion coefficients for the proton exchange process are obtained. The evolution characteristics of the waveguide index profile in the annealing process are studied. The structural deformation of the proton exchange waveguides in Mg O:LiNbO.3 and LiNbO.3 and the restoration effect of annealing are also studied tho roughly by the x-ray diffraction method and the OH-infrared absorption method. The optical and structural characteristics of annealed proton exchange waveguides in MgO:LiNbO.3 and LiNbO.3 are analysed and compared with eath other.
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| 2. |
- Chen, L., et al.
(författare)
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Analysis for the propagation of evanescent waves and the photo tunneling effect in a multi-layered structure containing materials with negative refractive index
- 2003
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Ingår i: Wuli xuebao. - : Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences. - 1000-3290. ; 52:10, s. 2386-2392
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Tidskriftsartikel (refereegranskat)abstract
- The propagation properties of evanescent waves in a multi-layered structure containing materials with negative refractive index are analyzed. The decay or magnification of the amplitude of evanescent waves in different situations is explained analytically in detail. In particular, the influence of the dissipation of the negative refractive index medium on the photon tunneling effect is discussed. The propagation and energy storage of evanescent waves are shown clearly by using the incidence of a Gauss beam.
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| 3. |
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| 4. |
- Cheng, C., et al.
(författare)
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Optimization and elimination of black center of a large-bore copper vapor laser
- 2000
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Ingår i: Wuli xuebao. - : Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences. - 1000-3290. ; 49:7, s. 1267-1272
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Tidskriftsartikel (refereegranskat)abstract
- Applying a genetic algorithm and taking the maximum output as an objective funct ion, a copper vapor laser with about 100W output is optimized and designed for reducing the “black center” of the radial laser intensity. The “black center ”, which results from the skin effect of the continuing pulsed field, is reduce d and the output is increased significantly by optimizing the laser tube radius- length and the LC circuit parameters.
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| 8. |
- He, Sailing, et al.
(författare)
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Synchrotron radiation photoemission study of Yb2.75C60
- 2005
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Ingår i: Wuli xuebao. - : Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences. - 1000-3290. ; 54:3, s. 1400-1405
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Tidskriftsartikel (refereegranskat)abstract
- The Yb275C60 thin film was prepared and studied by using the synchrotron radiation ultraviolet photoemission spectroscopy(PES) in an ultrahighvacuum system. The spectral line obtained in the range between the Fermi level and ～5 eV binding energy consists of those lines from the valence band (the molecular orbital LUMO, HOMO and HOMO1 derived energy bands of C60) and core levels(Yb 4f7/2 and 4f5/2). Taking into account the variations of the photoinization cross sections of C 2p and Yb 4f with different photon energies, we have measured the photoemission spectra under the condition of varying photon energies, and carried out simulations to deduce the component contributions. The peak positions, widths and intensities for the components are obtained quantitatively. The results reveals that the photoemission of 4f electrons has a significant intensity with the photon energies larger than ～300 eV, and that the measured spectra depart drastically from the density of states of the valence band. To observe the valence band structure, one should carry out the PES measurements by using photons with energies less than 300 eV. The photoionization crosssection oscillation is also observed in Yb275C60 with almost the same oscillation period as that for pure C60 However, the oscillation amplitude is obviously smaller than that for pure C60, which reveals that the chemical environment of C60 in compounds has nonnegligible effects on the photoionization crosssection oscillation phenomenon.
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| 9. |
- Li, H. N., et al.
(författare)
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Valence band photoemission of Yb2.75C60
- 2004
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Ingår i: Wuli xuebao. - : Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences. - 1000-3290. ; 53:1, s. 244-247
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Tidskriftsartikel (refereegranskat)abstract
- Valence-band electronic density of states of Yb2.75C60 thin films was measured by the ultraviolet photoemission spectrum technique. The phase-pure Yb2.75C60 sample was characterized by the C 1s XPS measurements. The result indicates Yb2.75C60 has no Fermi edge and thus is semiconductor. The hybridization between 6s state of Yb and the LUMO band of C60 cannot be considered to be negligible. Some Yb 6s electrons occupy the Yb-C60 covalent band in Yb2.75C60.
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| 10. |
- Wang, Q., et al.
(författare)
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Simulation and comparison study of liquid crystal director distributions
- 2001
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Ingår i: Wuli xuebao. - : Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences. - 1000-3290. ; 50:5, s. 926-932
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Tidskriftsartikel (refereegranskat)abstract
- A new finite-difference iterative method is used to calculate the distribution of the liquid crystal directors under an applied voltage.Numerical results for twisted nematic,super twisted nematic,and hybrid nematic cells are given.In comparison with Newton's method and the relaxation method, it in shown that the new method is simpler,more stable to give accurate results for various types of liquid crystal cells.
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