132 publications from this institution
A special method “conduit synthesis technology” has been utilized to produce spherical nickel hydroxide powders with different chemical compositions. Three kinds of powers A, B, C were prepared by chemically coprecipitating Ni, Co, Zn, Ca, Mg and Cu. It was found that powder B produced better performance than the others. The discharge capacities of powder B could achieve 280mAhg−1 for both 1C and 2C rates at 65°C, respectively. The cyclic voltammetry analysis showed that the difference between the oxidation potential and the oxygen evolution potential of powder B is 122mV. It indicated that Co could improve conductivity of electrons, restrict the oxygen evolution reaction and thus promote the high rate charge/discharge and high-temperature performance. Ca and Mg might effectively enhance the oxygen evolution potential in the charge process. Furthermore, the proper addition of Zn, Ca and Cu could lower the ionization energy and elevated the transition energy, and thus the transfer of electrons in electrode materials was accelerated and the electrochemical performance of nickel hydroxide electrode was improved. It was a promising way to improve the electrochemical performance of spherical nickel hydroxide for Ni–MH batteries.
Safety of cable net structures has been threatened due to rising conflicts and the possibility of exposure to blast load. Pre-tensioned cable nets are geometrically nonlinear problems and the nonlinearity can be addressed by using the linearized stiffness matrix method (LSM). On the other hand, the effect of negative phase pressure of blast wave is usually ignored in practice while the research indicates its significance on the dynamic response of the system. In this paper, LSM method is used to study the effect of negative phase pressure and other factors such as charge weight, standoff distance, pretension level, and modal frequency on cable net structures. The effect of glass panel failure on the system response is also studied by removing the corresponding wave pressure acting on the failed glass panels. Accuracy of the LSM method is evaluated through comparison between the proposed numerical and closed-form solution. The results indicate the significance of the effect of negative phase pressure on the system response, which is pronounced at lower TNT weights and more flexible structures. The major effect of negative phase pressure is on the outward displacements, which exhibits up to 25% more displacements for the studied cable net when the negative phase pressure is considered. Failure of glass panels and consequent pressure release in negative phase can cause increase in the subsequent displacements. LSM method can reliably predict the system response as far as displacements are not too large. However, at very large displacements, LSM method significantly overestimates the predicted displacements.
