Time filter

Source Type

Tongren, China

Zhang J.-F.,Xiamen University | Zhang J.-F.,Tongren University | Lu J.-F.,Xiamen University
Astrophysical Journal

In order to understand the main observational characteristics of the Galactic X-ray binary Cygnus X-3, we propose a radiation model in which high-energy electrons accelerate in the dissipation zone of a jet and produce nonthermal broadband emissions. Broadband spectral energy distributions are computed to compare the AGILE and Fermi LAT data with the multi-band data during soft X-ray spectral states. By fitting observations at different locations of the jet, we find that the emission region is rather compact and should be located at a distance of about one orbital radius. Our results can explain the current multi-frequency observations and also predict the TeV band emission. The model could be tested by a polarization measurement at IR band, and/or by a correlation study between the GeV and TeV bands once very-high-energy observations are available. © 2015. The American Astronomical Society. All rights reserved. Source

She Y.,Xiangtan University | Zheng X.,Xiangtan University | Wang D.,Xiangtan University | Zhang W.,Tongren University
Optics Express

We consider the coupling effect between interdot tunneling coupling and external optical control field to study the linear optical property and the formation of temporal optical solitons in a quantum dot molecules system, analytically. The results show that the double tunneling induced transparency (TIT) windows are appeared in the absorption curve of probe field because of the formation of dynamic Stark splitting and quantum destructive interference effect from the two upper levels. Interestingly, the width of the TIT window becomes wider with the increasing intensity of the optical control field. We also find that the Kerr nonlinear effect of the probe field can be modulated effectively through coherent control both the control field and the interdot tunneling coupling in this system. Meanwhile, we demonstrate that the formation of dark or bright solitons can be practical regulated by varying the intensity of the optical control field. © 2013 Optical Society of America. Source

Zhang J.-F.,Tongren University | Xie F.-G.,Chinese Academy of Sciences
Monthly Notices of the Royal Astronomical Society

Under the framework of the magnetized accretion ejection structures, we analyse the energy balance properties, and study the spectral energy distributions (SEDs) of the jet-emitting disc (JED) model for black hole X-ray transients. Various radiative processes are considered, i.e. synchrotron, bremsstrahlung, and their Comptonizations, and external Comptonization of radiation from the outer thin disc. With these cooling terms taken into account, we solve the thermal equilibrium equation self-consistently and find three solutions, of which the cold and the hot solutions are stable. Subsequently, we investigate the theoretical SEDs for these two stable solutions. We find the hot JED model can naturally explain the spectra of the Galactic microquasars in their hard states. As an example, we apply this model to the case of XTE J1118+480. © 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. Source

Chen H.,Shanghai Nanotechnology Promotion Center | Leng S.,Tongren University
Ceramics International

Hollow nano-structured hydroxyapatite [Ca10(PO4)6(OH)2, HAp] microspheres were rapidly synthesized via microwave transformation of a sacrificial hard-template of similarly structured calcium carbonate (CaCO3) hollow microspheres in Na3PO4 aqueous solution. Results showed that the microwave process significantly increased transformation efficiency. Pure hollow HAp microspheres could be obtained within ultra-short-period of 30 min via the microwave transformation process, in comparison to over 48 h in the traditional hydrothermal transformation method. These studies suggest that the microwave assisted hard-template transformation process is an effective approach to synthesize HAp with high efficiency. The resulting hollow nano-structured HAp microspheres may have applications in drug-delivery and serve as materials for chemical and environmental applications. © 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved. Source

Wu S.-Z.,South China University of Technology | Wu S.-Z.,Tongren University | Li K.,South China University of Technology | Zhang W.-D.,South China University of Technology
Applied Surface Science

Heterostructured photocatalysts Ag3VO4/g-C3N4 were prepared by deposition-precipitation method in order to anchor Ag3VO4 on the surface of N-vacancy g-C3N4 (g-C3N4-VN). The photocatalytic activity of the samples was evaluated by degrading rhodamine B (RhB) in aqueous solution. Compared with the pure Ag3VO4 and g-C3N4-VN, the heterojuncted photocatalyst 65 wt% Ag3VO4/g-C3N4-VN exhibits the best activity under visible light irradiation. The photodegradation rate constant of 65 wt% Ag3VO4/g-C3N4-VN is 0.0556 min-1, which is 23.4, 5.8 and 6.4 times of that of pure Ag3VO4, pure g-C3N4-VN and P25, respectively. The excellent photocatalytic performance of the Ag3VO4/g-C3N4-VN catalysts can be ascribed to the matched band structures of Ag3VO4 and g-C3N4, which strengthened the formation of the heterojuncted photocatalyst. The unique heterostructured photocatalyst is favorable for retarding the recombination of photogenerated electrons and holes, thus the photocatalytic activity is significantly increased. Further experiment also reveals that the •O2 - and h+ are the major active species in the degradation of RhB. © 2014 Elsevier B.V. All rights reserved. Source

Discover hidden collaborations