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Zhang H.,Harbin Institute of Technology | Chen G.,Harbin Institute of Technology | He X.,Harbin Institute of Technology | Xu J.,Heilongjiang Institute of Technology
Journal of Alloys and Compounds | Year: 2012

Recently, ion-codoped semiconductor systems have been employed as photocatalysts with the objective of improving their photocatalytic activities under visible-light irradiation. In this paper, the effects of monovalence silver ion and trivalence lanthanum codoping into the photocatalytic activity of CaTiO 3 powder for overall water splitting were studied experimentally and theoretically. Pure and Ag-La codoped CaTiO 3 powder, prepared by sol-gel method which is assisted with ultrasonic technique for the first time, is further characterized by ultraviolet-visible (UV-vis) absorption spectroscopy. The UV-vis spectra indicate that the Ag +-La 3+ ions doping not only enhanced the photocatalytic activity under ultraviolet-visible (λ > 300 nm) light irradiation but also made the photocatalysts have visible light (λ > 400 nm) response. Photocatalytic activity of codoped CaTiO 3 powder for hydrogen evolution under UV light is increased dramatically than that of pure CaTiO 3 powder when the doping amount is 3 mol%. The electronic structures of pure and codoped CaTiO 3 were investigated using density functional theory (DFT). The results of DFT calculation illuminate that the visible-light absorption bands in the Ag-La codoped CaTiO 3 catalyst are attributed to the band transition from the Ag 4d5s to the O 2p + Ti 3d hybrid orbital. © 2011 Elsevier B.V. All rights reserved.

Yang C.,Heilongjiang Institute of Technology
Material Science and Environmental Engineering - Proceedings of the 3rd annual 2015 International Conference on Material Science and Environmental Engineering, ICMSEE 2015 | Year: 2016

Understanding pressure-driven flow into capillary is important in microcasting technology. We establish experimentally a certain liquid–solid system, or mercury–mica system. The contact angle formed by a drop of liquid on the solid surface is measured using the contact angle meter. It is found that the contact angle decreases by about 20o as the radius of droplet decreases from 0.325 mm to 0.03 mm. The theories for pressure-driven flow are generalized to a nonlinear second-order differential equation, which takes the effects of the external pressure force, the inertial force, and the contact angle into account. The critical external pressure difference is obtained via the differential equation. The influence of contact angle on the critical external pressure difference is significant due to the change of contact angle with drop size, and the difference between the theoretical result and the experimental result at r0 = 0.02 mm is up to 12.5 kPa. © 2016 Taylor and Francis Group, London.

Li X.,Heilongjiang Institute of Technology
Advanced Materials Research | Year: 2012

Based on dynamic data system(DDS) modeling methodology, after transformed a seasonal time series for total electron content(TEC) of the ionosphere into a stationary time series by differencing technique, stationary TEC values are modeled by the autoregressive(AR) model. In order to correct model's systematic errors, authors proposed that AR model is improved by non-parameters introduced to AR model and the ionospheric TEC is predicted using the improved AR model which is called semi-parametric AR model. Preliminary results show that the semi-parametric AR model has a good performance than one of the AR model for short-term TEC prediction while, for relatively long-term TEC prediction, the performance of the semi-parametric AR model is no less than one of AR model. © (2012) Trans Tech Publications.

Li Y.,Heilongjiang Institute of Technology
Lecture Notes in Electrical Engineering | Year: 2016

Traditional timing synchronization methods require the identification of the peak value of the timing metric to realize the synchronization estimation. The proposed method in this paper requires only finding the peak plateau of the time metric and the terminal edge of the peak plateau. Consequently, the time metric of the novel method proposed in this paper could have no sharp peak value. A threshold to process the symbol timing metric in the proposed method must be established, after which it is easy to find the terminal end edge of the peak plateau, thus making the proposed method less complex. © Springer-Verlag Berlin Heidelberg 2016.

Jiang P.,Harbin Institute of Technology | Jiang P.,Heilongjiang Institute of Technology | Kar S.,Harbin Institute of Technology | Zhou Y.,Harbin Institute of Technology
Physics of Plasmas | Year: 2013

The nonthermal effects on the doubly excited resonance states of the hydrogen negative ion and helium atom are investigated in Lorentzian astrophysical plasma environments using highly correlated Hylleraas-type wave functions in the framework of the stabilization method. Resonance parameters (resonance position and width) are reported for the first time as functions of the spectral index and plasma parameter. The screening effects are more pronounced in the stronger screening region. © 2013 American Institute of Physics.

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