| 1. |
- Wang, S. Y., et al.
(författare)
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High-spin level scheme of Cs-126
- 2004
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Ingår i: Gaoneng wuli yu he wuli. - 0254-3052. ; 28:5, s. 491-494
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Tidskriftsartikel (refereegranskat)abstract
- High-spin states of Cs-126 have been populated via the Cd-116(N-14, 4n) Cs-126 reaction. The experiment was performed at Niels Bohr Institute in Denmark in 1991. After careful data analysis, most of the previously-known bands have been pushed up to much higher spins and 3 new rotational sequences have been identified. Spin, parity and configuration assignments are tentatively proposed for all of the observed bands.
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| 2. |
- Liang, G-B, et al.
(författare)
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Modified regularization method applied to the inversion of particle size distribution from light scattering data
- 2006
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Ingår i: Guangdian Gongcheng. - 1003-501X. ; 33:12, s. 44-49
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Tidskriftsartikel (refereegranskat)abstract
- Laser particle size analyzer is one of the instruments for particle size analysis. Recent developments focus on various algorithms for particle size analysis via light energy distribution based on the Mie scattering theory in the laser analyzer. The determination of the particle size distribution (PSD) from the analyzer requires the inversion of the Fredholm integral equation of the first kind. This equation is an ill-posed one, which can be analyzed by effective algorithms. This paper presents a modified regularization method applied to the inversion of the PSD with the independent models. The Generalized Cross-Validation (GCV) method was used for the selection of a regularization parameter. The Successive Over-Relaxation (SOR) iterative method was applied to improve the exactness and stability of the convergent result. The simulation with the models was carried out. The simulated results are in a good agreement with the data measured from nine standard particulate samples as well as their mixtures. It is indicated that this method can be feasible and effective for the simulation of the PSD from the corresponding light scattering data.
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| 3. |
- 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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| 4. |
- Fan, Y., et al.
(författare)
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Mechanical preparation of nano titanium dioxide powder and its optical properties
- 2007
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Ingår i: Journal of the Chinese Ceramic Society. - 0454-5648. ; 35:7, s. 832-837
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Tidskriftsartikel (refereegranskat)abstract
- mechanical preparation of the nano-sized particles of TiO2 powder by a stirred bead mill was investigated. The particle sizes of the ground products were determined by the acoustic particle sizer, the nitrogen gas adsorption method and a scanning electron microscopy. The diameter of the nano-sized particles, which were obtained after milling for 7 h, is about 50 nm and the specific surface area is up to 70 m2/g. The surface and structure of the samples have been investigated with X-ray diffraction. It is indicated that an intense comminution in the mill leads to a progressive loss in crystallinity of TiO2. The catalytic degradation of methyl orange in water was also studied by a photometer. The results show that the nano-sized particles of TiO2 powder prepared by milling possess photocatalysis effect and are capable of absorption of ultraviolet radiation
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| 5. |
- 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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| 6. |
- Ma, Y., et al.
(författare)
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Theoretical studies on electronic transport properties of six-membered heterocyclic molecules
- 2006
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Ingår i: Wuli xuebao. - : Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences. - 1000-3290. ; 55:4, s. 1974-1978
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Tidskriftsartikel (refereegranskat)abstract
- By applying the elastic scattering Green's function theory in combination with the hybrid density function theory, the electronic transport properties of molecular junctions constructed by the six-membered heterocyclic molecules, pyridazine-2, 5-dithiol, pyrazine-2, 5-dithiol, and pyrimidine-2, 5-dithiol, have been studied. For the heterocyclic molecule pyridine, the influence of the terminal atoms on the current-voltage characteristics has also been obtained. We have accurately determined the coupling constant between the molecule and electrodes by using the frontier molecular orbital theory and the perturbation method. The numerical results show that pyridazine-2,5-dithiol has higher current and conductance, while the conductance of pyrimidine-2, 5-dithiol is very small when the bias voltage is lower than 4V. The conductivity of the molecule pyridine with selenium atom as the terminal atom is higher than that with oxygen atom or sulfur atom.
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| 7. |
- Shi, F., et al.
(författare)
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Synthesis and properties of a new donor model compound for PSII
- 2004
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Ingår i: Gaodeng xuéxiào huàxué xuébào. - 0251-0790. ; 25:9, s. 1666-1672
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Tidskriftsartikel (refereegranskat)abstract
- As a model compound for redox components on the donor side of photosystem II (PS II) in green plants, a supramolecular complex 2 was synthesized and characterized. In this complex, two {[(2-hydroxy-3-(morpholin-4-ylmethyl)-5-tert-butyl-benzyl)(pyridyl-2-methyl)amino]methyl} arms are linked to the ortho-positions of a phenol which is expected covalently to be linked to Ru(II) tris-bipyridine through an amide bond. The arms on the substituted-phenol can coordinate two Mn(III) ions. The structure of complex 2 was confirmed by electrospray ionization mass spectrometry (ESI-MS) and 2D-NMR (gCOSY, HSQC and HMBC). Its photochemical and electrochemical properties were studied. The results showed that the MLCT band of the compound was red-shifted compared to that of [Ru(byp)(3)](2+) and the luminescence quantum yield was enhanced. In addition, the oxidation potential of ruthenium was higher than the phenol(+)/phenol and Mn(III, IV)/Mn(III) which was consisted with the electron transfer sequence of the donor side of PS II in nature. All these showed that this compound was a good model to mimic the donor side of PS II.
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| 8. |
- Zhao, K., et al.
(författare)
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Studies on two-photon absorption cross-sections of 1,4-dimethoxy-2,5-divinyl-benzene derivatives
- 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. ; 54:6, s. 2662-2668
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Tidskriftsartikel (refereegranskat)abstract
- The one-photon and two-photon absorption properties of a series of 1, 4-dimethoxy-2, 5-divinyl-benzene derivatives are investigated by use of the analytic response theory at HF level. The one-photon and two-photon fluorescence spectra of E, E-2-5Bis[4'-(N, N-di-n-butylamino) styryl]-1 4-dimenthoxybenzene are measured. The numerical results show that these molecules have strong two-photon absorption cross sections. In the visible light region, the maximal one-photon absorption strengths of the molecules occur in the first excited state. Furthermore, the maximal two-photon absorption cross sections of the D-pi-A typed molecules still appear in the first state, but for D-pi-D typed molecules the second excited state has the maximal two-photon absorption cross-section. The optical properties of the molecules are closely related to the electric property of the donor and acceptor. The symmetrically substituted molecules can not be determined to have a larger two-photon absorption cross section than the asymmetrically substituted molecules for such a kind of pi-center. The charge-transfer process for the charge-transfer states is displayed, and then the mechanism of photopolymerization is discussed qualitatively.
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