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Your search keyword '"Zheng, W. M."' showing total 123 results
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123 results on '"Zheng, W. M."'

1. Finite temperature excitations of an inhomogneous trapped Bose gas with Feshbach resonances

Author

Yi, X. X., Zhou, D. L., Sun, C. P., and Zheng, W. M.

Subjects
Quantum Physics
Abstract

We derive and discuss the temperature dependance of the condensate and noncondensate density profile of a Bose-Einstein condensate gas with Feshbach resonance in a parabolic trap. These quantities are calculated self-consistently using the generalized Hartree-Fock-Bogoliubov (HFB) equations within the Bogoliubov approximation. At zero temperature, the HFB equation can be solved by means of a variation method that give the low excitation spectrum. Moreover, within the two-body collision theory, we estimate the relationship between the atom number and the external magnetic field $B$, it is in good agreement with the data in recent experiments., Comment: 9 pages, 3 figures

Published
2000
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3. Impedance matching system using triple liquid stub tuners for high-power ion cyclotron resonance heating in EAST tokamak

Author

Liu, L. N., primary, Wang, L., additional, Yuan, S., additional, Mao, Y. Z., additional, Saito, K., additional, Zhang, X. J., additional, Qin, C. M., additional, Liang, Q. C., additional, Long, X. Y., additional, Zhao, Y. P., additional, Cheng, Y., additional, Zhang, W., additional, Yang, H., additional, Zhu, G. H., additional, Zhang, K., additional, Ping, L. L., additional, Ai, L., additional, Guo, Y. Y., additional, Wang, G. X., additional, Zheng, W. M., additional, Gao, X., additional, Lin, X. D., additional, and Wu, M. Q., additional

Published
2022
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6. Ionospheric Response to the Total Solar Eclipse of 22 July 2009 as Deduced from VLBI and GPS Data

Author

Guo, L, Shu, F. C, Zheng, W. M, Kondo, T, Ichikawa, R, Hasegawa, S, and Sekido, M

Subjects
Geophysics
Abstract

A total solar eclipse occurred over China at latitudes of about 30 N on the morning of 22 July 2009, providing a unique opportunity to investigate the influence of the sun on the earth's upper ionosphere. GPS observations from Shanghai GPS Local Network and VLBI observations from stations Shanghai, Urumqi, and Kashima were used to observe the response of TEC to the total solar eclipse. From the GPS data reduction, the sudden decrease of TEC at the time of the eclipse, amounting to 2.8 TECU, and gradual increase of TEC after the eclipse were found by analyzing the diurnal variations. More distinctly, the variations of TEC were studied along individual satellite passes. The delay in reaching the minimum level of TEC with the maximum phase of eclipse was 5-10 min. Besides, we also compared the ionospheric activity derived from different VLBI stations with the GPS results and found a strong correlation between them.

Published
2010

8. Acceptor binding energy in δ-doped GaAs/AlAs multiple-quantum wells.

Author

Zheng, W. M., Halsall, M. P., Harmer, P., Harrison, P., and Steer, M. J.

Subjects
*BINDING energy, *PHOTOLUMINESCENCE
Abstract

A series of Be δ-doped GaAs/AlAs multiple-quantum wells with the doping at the well center were grown by molecular beam epitaxy. The photoluminescence spectra were measured at 4, 20, 40, 80, 120, and 200 K, respectively. The two-hole transitions of the acceptor-bound exciton from the ground state, 1 S[SUB3/2](Γ6), to the first-excited state, 2S[SUB3/2](Γ6), have been clearly observed and the acceptor binding energy measured. A variational calculation is presented to obtain the acceptor binding energy as a function of well width. Ir is found that the experimental results are in good agreement with the theory. [ABSTRACT FROM AUTHOR]

Published
2002
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9. The effect of interference on magneto-optics in magneto-optical layered structures.

Author

Wang, Y., Zheng, W. M., Zhou, S. M., Chen, L. Y., Zhu, W. R., Qian, D. L., Zheng, Y. X., Zhang, H. Y., and Huang, J.

Subjects
*MAGNETOOPTICS, *FARADAY effect
Abstract

In this article the magneto-optics of magneto-optical (M-O) layered structures have been studied theoretically and experimentally. For the air/M-O/air configuration, an analytic expression between the apparent complex Faraday rotation and the eigenvalue &φtilde;[sub F] = e[sub 1]&φtilde;'[sub F] can be obtained, when the M-O layers are semitransparent and weakly magnetic. The interference factor e[sub 1] is a function of the optical constants and the M-O layer thickness d, and the light wavelength. In these structures, the apparent Faraday rotation consists of two parts. One oscillates as a function of the M-O layer thickness and the other is proportional to the layer thickness. The oscillation period and the amplitude are determined by the optical constants of the M-O layers. For the air/M-O/reflector configuration, the Kerr rotation &φtilde;[sub k] oscillates as a function of the M-O layer thickness and approaches a constant as the thickness d → ∞. If the M-O layers are semitransparent and weakly magnetic, the apparent Kerr rotation can be expressed as &φtilde;[sub k] = e[sub 2] &φtilde;'[sub F]. For ultrathin metallic magnetic bilayered films the Kerr rotation is proportional to the M-O layer thickness and the enhancement factor is a function of the optical constants of the M-O layer and NM reflector. The magneto-optics of a Co spinel ferrite film, Co/Cu, Fe-Ni/Cu, and Co/Si structures have been studied experimentally. [ABSTRACT FROM AUTHOR]

Published
1997
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38. Localization of Immunoglobulin G γ-Chain mRNA-Expressing Cells in the Oviduct of Laying and Diethylstilbestrol-Treated Immature Hens

Author

Zheng, W. M., Izaki, J., Furusawa, S., and Yoshimura, Y.

Abstract

The purpose of this study was to determine the synthetic sites of IgG in the chicken oviduct by localizing IgG γ-chain mRNA (IgGγ mRNA)-expressing cells and the effects of estrogen on their population. Paraffin sections of oviducal tissues from laying hens (approximately 57 weeks old) and immature hens (approximately 16 weeks old) with or without diethylstilbestrol (DES) treatment were hybridized by digoxigenin-labeled IgG riboprobes or immunostained for IgG γ-chain (IgG). Immunoreactive IgG was present in some of the mucosal epithelial cells and the plasma cell-like cells in the stromal connective tissue in all segments of the oviduct. In contrast, IgGγ mRNA expression was observed only in the plasma cell-like cells in the stromal connective tissues, but not in the cells of mucosal epithelium. In laying hens, the lower end of the oviduct, namely the vagina and uterovaginal junction, contained more IgGγ mRNA-expressing cells than the other segments. Treatment of immature hens with DES for 3 or 6 days increased the population of both IgGγ mRNA-expressing cells and IgG-containing cells in the oviducal stroma. These results indicate that IgG is locally produced by plasma cell-like cells in the stroma, but not by the cells of the mucosal epithelium, and estrogen may stimulate the infiltration of IgG-producing plasma cell-like cells into the oviducal stroma.

Published
2000
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40. Isolation of microsatellite loci from expressed sequence tag library of Puccinia striiformis f. sp. tritici.

Author

CHEN, C. Q., ZHENG, W. M., BUCHENAUER, H., HUANG, L. L., LU, N. H., and KANG, Z. S.

Subjects
*PUCCINIA striiformis, *STRIPE rust, *FUNGAL diseases of plants, *MICROSATELLITE repeats, *GENES, *WHEAT diseases & pests
Abstract

We described twenty polymorphic microsatellite loci derived from the expressed sequence tags of Puccinia striiformis f. sp. tritici, which causes yellow rust disease on wheat. The numbers of alleles range from two to six and eight microsatellite loci show significant similarities to known genes. Observed and expected heterozygosities ranged from 0.12 to 0.78 and from 0.24 to 0.87, respectively. [ABSTRACT FROM AUTHOR]

Published
2009
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45. Exact results for the diffusion in a class of asymmetric bistable potentials

Author

Hongler, M. O. and Zheng, W. M.

Abstract

We solve the Fokker-Planck equations with drifts deriving from a class of asymmetric nonharmonic potentials which include bistable cases. An analytical expression for the probability current over the potential barrier is obtained. Finally, we compare our exact results with those obtained by Kramers' approximation. © 1983 American Institute of Physics.

46. Exact solution for the diffusion in bistable potentials

Author

Hongler, M. O. and Zheng, W. M.

Subjects
bistable potentials, Fokker-Planck equation, exactly solved models
Abstract

We solve analytically the Fokker-Planck equation for a one-parameter family of symmetric, attractive, nonharmonic potentials which include double-well situations. The exact knowledge of the eigenfunctions and eigenvalues allows us to fully discuss the transient behavior of the probability density. In particular, for the bistable potentials, we can give analytical expressions for the probability current over the working barrier and for the onset time which characterizes the transition from uni- to bimodal probability densities. © 1982 Plenum Publishing Corporation.

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