Advanced Materials Research Vols. 512-515

Abstract: Hawking radiation of massive particles via tunneling from the stationary axial symmetric Einsein-Born-Infeld black hole is studied. The result shows that, when self-gravitation interaction is considered, the exact spectrum is not precisely thermal, but satisfies the unitary theory. In special case, we also reduce the result to obtain the Hawking effect via tunneling from the Schwarzschild, Kerr and Kerr-Newman black hole.

Abstract: A new method was used to synthesize the cathode material Li1+xV3O8, and it simplified the process of preparing and shortened the time of reaction in comparison with previous Sol-gel method with the citric acid. The characteristics of Li1+xV3O8 were investigated by X-ray diffraction, thermogravimetry and differential thermal analysis, and transmission electron microscopy, which showed the material Li_1+xV₃O₈ with a good thermal stability had been obtained via the new method. The electrochemical performance of Li_1+xV₃O₈ was measured, which indicated that the material obtained had a remarkable discharge capacity of 380mAh/g and a good cycle performance.

Abstract: The Jintan energy storage of salt rock in Jiangsu Province is a demonstration project; and the creep similar material is made up of fine iron, coarse salt rock, fine salt powder, epoxy rosin and ethylenediamine. According to the similarity theory and measured physical and mechanical parameters of salt rock from Jintan, the uniaxial compressive test, creep test, different material proportions are carried out on the similar material. And we found that the bulk density, Poisson’s ration, elastic modulus, compressive strength and deformation characters of the similar material are similarly with the Jintan salt rock. Especially, the creep behavior of similar materials can reflect the Jintan salt rock long-term creep with a relatively short time, which supplies reliable similitude model material for energy storage long-term creep test.

Abstract: Graphene oxide nanoplate-MnO₂ composites have been synthesized by oxidizing part of the carbon atoms in the framework of graphene oxide nanoplates at ambient temperature. The composites were characterized by scanning electron microscopy (SEM) and cyclic voltammetry (CV). Their microstructures and morphologies have affected their electrochemical properties. Compared with MnO₂ nanoparticles, the nanocomposite prepared reveals better electrochemical properties as a supercapacitor electrode material.

Abstract: The electrochemical performance of polyaniline (PANI)/stainless steel electrodes prepared in H₂SO₄ and p-toluene sulfonic acid (p-TSA) using potentiodynamic method were investigated in corresponding acids and three kinds of sodium salts, respectively, by cyclic voltammetry, galvanostatic charge-discharge cycling and electrochemical impedance spectroscopy (EIS). It is concluded that the counter anion of acid employed in the electropolymerization plays a key role in the free volume of PANI. The kinetic parameters of PANI are strongly influenced by the free volume both in acid and in salt solutions. In addition, the utilizing of salt solution is beneficial to the kinetic analysis of the energy-storage process of PANI, although the capacitance of PANI in salt solution decays on cycling due to the lack of protons.

Abstract: The multiple linear regression method is used, the method of calculating the active power flow and the unit output is discussed , a simple approximate expression is designed, and the corresponding error value is given. a simple calculation rules of congestion cost is given, calculation rules for the actual cost minus the theoretical costs and requirements of the actual costs is as low as possible to avoid blocking; Block can not be avoided, then try to avoid the wind up.

Abstract: In recent years, solid clathrate gas hydrates are considered to be promising materials for hydrogen storage because they can trap molecular hydrogen within their cages formed by a hydrogen-bond water network. In this paper, we firstly synthesized the nitrogen hydrates, and then used these hydrates for hydrogen storage. The H₂ storage potential in these hydrates is investigated by Raman spectrometry technique. The spectral properties show that the multiple H₂ occupancies of large cages of N₂ hydrates have been realized under mild condition (16 MPa and 255 K) when exposing N₂ hydrates in pressurized H2 gas. The results suggest that nitrogen clathrate hydrates are prospective media for H₂ storage and may help to design and produce new hydrogen storage materials.

Abstract: In order to store the solar energy efficiently, high temperature phase change material (HTPCM) through dispersion of nanoparticles is reported. Based on the enthalpy-porosity approach, the numerical model is first validated by comparing the results of the reference. Then the melting processes of HTPCM with different mass fraction nanoparticles in an enclosure are conducted. Results show that nanoparticles can greatly increase melting rate, compared with that of HTPCM, so nanoparticle-enhanced phase high temperature change material (NEHTPCM) has a promising application for solar energy storage.

Abstract: Finite element method has been used to analysis the stress of inner pipes of low temperature storage tank for LNG caused by temperature, pressure and weight. Filling liquid state, storing liquid state and unloading liquid state are considered in this paper. The results show that the stress of the top pipes would be the largest under filling liquid state which is only little larger than storing liquid state. The stress of the bottom pipes would be the largest under storing liquid state. The deformation of the inner container of the tank would influence the stress distribution. Choosing a flexible structure as designing the bottom pipes is reasonable.

Abstract: A method of conventional chemical reaction to prepare delithiated cathode materials of Li-ion battery has been introduced. The cathode material of Li-ion battery was mixed with oxidizing agent Na₂S₂O₈ in water, and the liquid was stirred continuously to make the chemical reaction proceed sufficiently, then the reaction product was filtered, finally the insoluble delithiated cathode material was obtained. A series of tests were conducted to verify the composition, crystal structure and electrochemical property of the delithiated cathode materials were all desirable. This method overcomes the shortcomings of battery charging preparation and chemical extraction preparation employing other oxidizing agents.