Zhang W.,Nanjing Forest Police College |
Hou Z.F.,Xiamen University
Journal of Applied Physics | Year: 2014
The influence of gadolinium (Gd) doping on the oxygen vacancy (V O) in monoclinic HfO2 have been studied by the first-principles calculations within the spin-polarized generalized gradient approximation plus Hubbard U approach. It is found that the Gd dopant and V O show strong attractive interaction, resulting in a cooperative effect that the substitution of Gd for Hf (GdHf) would increase the probability of oxygen vacancies generation and vice versa. The GdHf is more energetically favorable to be next to the vacancy site of a three-coordinated oxygen (O3), forming a complex defect GdHf + V O. A single GdHf acts a hole donor and passivates the defect states of VO. Our results suggest that the decrease of the VO-related defect states observed in the photoluminescence spectra of Gd-HfO2 is because Gd doping passivates the defect states of V O, rather than caused by decrease of VO concentration. Our findings would clarify the debate about the influence of Gd doping on the oxygen vacancies in HfO2. © 2014 AIP Publishing LLC.
Wei Y.,Nanjing Forest Police College
Chemistry Letters | Year: 2014
Activated carbon microtubes (CMTs) have been prepared from poplar catkins by chemical activation with ZnCl2. The assynthesized porous CMTs have large inner tubes of several micrometers, large BrunauerEmmettTeller surface areas of up to 1400m2 g11, a complex porous structure with predominant micropores (280 vol%), and small amount of mesopores (-20 vol%). Two-electrode supercapacitor cells constructed with the activated CMTs yield a specific capacitance of 206 F g11 and an energy density of 7.5Wh kg11 with aqueous electrolyte, values that are much higher than those of an activated carbon (160 Fg11, 5.5Wh kg11). © 2014 The Chemical Society of Japan.
Chen M.,Nanjing University of Aeronautics and Astronautics |
Mei R.,Nanjing Forest Police College |
Jiang B.,Nanjing University of Aeronautics and Astronautics
Mathematical Problems in Engineering | Year: 2013
We propose a robust sliding mode control (SMC) scheme for a class of uncertain multi-input and multi-output (MIMO) nonlinear systems with the unknown external disturbance, the system uncertainty, and the backlash-like hysteresis. To tackle the continuous system uncertainty, the radial basis function (RBF) neural network is employed to approximate it. And then, combine the unknown external disturbance, and the unknown neural network approximation error with the affection caused by backlash-like hysteresis as a compounded disturbance which is estimated using the developed nonlinear disturbance observer. The robust sliding mode control based on the nonlinear disturbance observer and RBF neural network is presented to track the desired system output in the presence of the unknown system uncertainty, the external disturbance, and the backlash-like hysteresis. Finally, the designed robust sliding mode control strategy is applied to the near-space vehicle (NSV) attitude dynamics, and simulation results are given to illustrate the effectiveness of the proposed sliding mode control approach. © 2013 Mou Chen et al.
Liu Y.,Nanjing Forest Police College
International Journal of Simulation: Systems, Science and Technology | Year: 2015
Internet of things is known as the third wave of information industry after the computer and the Internet, but the study of the Internet of things is still in its infancy nowadays and there are still many challenges in the development and popularization of the Internet of things. It believes that massive data interaction mechanism of the Internet of things has a great significance to the development and popularization of the Internet of things. Under this assumption, the large data exchange based on the internet of things is studied in this paper. It describes the key technologies of the Internet of things in detail following a brief introduction of the development status quo and the existing problems of the Internet of things, then it presents the architecture of the Internet of things, conducts deep research regarding the mechanism of large data exchange, and finally it proposes the integrated design of data fast interactive platform. The experimental results prove the effectiveness of the model. Fast data exchange platform breaks through the traditional where the server acts as the center of data exchange mechanism. © 2015, UK Simulation Society. All right reserved.
Wu Y.,Nanjing Forest Police College
RISTI - Revista Iberica de Sistemas e Tecnologias de Informacao | Year: 2015
Objective: In order to strengthen the prevention and combating of network information crime. Method: Using the data traceability technology based on the trusted electronic forensics. Process: This paper introduced the application background and the importance of the role of electronic data forensics, elaborated the theoretical basis of the trusted forensic, studied the tracing technology of electronic data, displayed the data forensics technology and its workflow, and established the corresponding mathematical model. Result & Analysis: This paper studied the electronic data tracing system based on trusted forensics technology, analyzed the corresponding data of the system, and proofed out that the system can effectively carry on the trusted forensics to electronic data. Result: The electronic data tracing system in this paper can effectively carry on the recovery and tracing to electronic data, and promotes the social harmonious development.