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MWCNTs was oxidized by the oxidation system (V( H2SO4 : V( HNO3 = 3:1. In order to study the properties of re-adsorption, different reflux time was used to get different amounts of oxygen containing functional groups. The structure of the sample was characterized by Fourier transform infrared spectroscopy (FITR $, scanning electron microscope (SEM $ and BET nitrogen adsorption method. The results show that a large amount of reactive functional groups such as carboxyl was obtained on the surface of the MWCNTs. The pore structure and dispersity of the MWCNTs was changed after the oxidization. The most suitable oxidative reflux time was 1.5 h. And in this condition, the O-MWCNTs has the highest equilibrium re-adsorption water content (493% $ . The properties of re-adsorption and the amount of oxygen containing functional groups present certain positive correlation. So we realized that the oxygen containing functional group was very important to influence the properties of re-adsorption. [ABSTRACT FROM AUTHOR]

Based on B3LYP method of quantum chemistry methods, the optimized structure and frequency of the aromatic acid and single-molecule water system were calculated using the GAUSSIAN09 at B3LYP/6-311 + +G (d, p) level. Quantum chemical simulation was used to study the structure changes, charge distribution, frequency changes and the binding energy. AIM theory was used to study the electron density of the system topology. The results show that all the systems form two hydrogen bonds, the hydrogen 1 (the hydrogen atom in the carboxyl group as a proton donor) is stronger than the hydrogen 2 (the hydrogen atom in water as a proton donor) . The hydrogen 1 plays a leading role of affecting the binding energy. In the system of aromatic acid and single-molecule water, the binding energy is in the range of 38. 0-40. 0 kj/mol which decreases with the increase of aromatic ring. [ABSTRACT FROM AUTHOR]

In the modern power system, relay protection device is an important tool to ensure the safe operation of the power system and monitor the quality of electricity. Traditional microcomputer relay protection device has a low computing speed, and its protection principle is also imperfect. A device of relay protection based on dual cores TMS320F2808 + N78E366A is developed, the hardware of each module part is designed. The filtering performance of the full wave Fourier algorithm is compared with the differential full wave Fourier algorithm. Then the performance of the above two algorithms is verified through simulation, meanwhile the system algorithm and the sampling points are selected. Finally, the main program diagrams of system software have also been given. The device is fast, reliable, easy to maintain, strong anti-interference, cute size, and can been easily configured into various types protection and control according to users' needs. [ABSTRACT FROM AUTHOR]