An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
The audible noise generated by corona discharge has the N-type characteristic at the initial generation stage, and it is a typical shock wave. This shock wave usually only exists around the corona source with a tiny range, making it difficult to obtain its characteristics through experimental measurements. An electrosound-combined simulation of the corona discharge based on the shock wave theory was conducted, and the development process involving the corona discharge, shock wave, and sound wave was simulated. First, the corona was numerically simulated based on the 2D pin–plate axisymmetric hydrodynamic model. It was found that the plasma was mainly distributed near the axis of the corona field where the electric field changed violently, and the maximum value of the electric field appeared at the head of the discharge channel. Then, the plasma energy was equivalent to the explosive energy, and a plasma explosion shock model was established. It was found that the shock wave pressure had obvious positive and negative pressure zones, and the propagation velocity decays to the sound velocity gradually. Finally, the shock wave pressure derived by the explosion model was used as the acoustic source, and the acoustic wave propagation process was simulated. The simulated sound pressure waveform had the same characteristics as the relevant experimental measurement results, proving that the developed method possessed strong applicability and gave rise to a new angle for the simulation of corona-generated audible noise.
In order to solve the parameter optimization problem of traditional power system stabilizer, a novel power system stabilizer (PSS) design method is proposed based on synergy of bacterial forging and particle swarm optimization algorithm. Bacterial foraging algorithm may lead to delay in reaching global solution. Particle swarm optimization may lead to entrapment in local minimum solution and obtain imprecise search results. The new algorithm is proposed to combines both algorithms' advantages in order to get better optimization values. A coordinate optimization index based on multi-object and multiple operation conditions is presented so as to improve the damping ratios of electromechanical modes and increase the robustness of power system. In this paper, PSS design for single machine infinite bus is formulated as multi-objective and multi-operating conditions, and the hybrid approach involving bacterial foraging and particle swarm optimization algorithm is employed to solve this problem. The results of both eigenvalue analysis and nonlinear simulation show that the proposed PSS can damp the low-frequency oscillations effectively and work well with high control performance under different operating conditions. Compared with PSS which is design by genetic algorithm, the proposed PSS in this paper has better damping characteristics.
The development of Li7La3Zr2O12 solid state electrolyte is retarded by its low ionic conductivity and surface passivation. A few studies suggest those two hurdles can be solved together. Capitalizing on similar physical and chemical properties of Hf4+ and Zr4+, Hf4+ doped Li7La3Zr2-xHfxO12 (x = 0.3, 0.4, 0.5, and 0.6) is prepared and the influence of Hf4+ on the structure and electrochemical performance of LLZO is investigated systematically. LLZO with Hf4+ doping is transformed into cubic phase, and also reduces the secondary reaction between H2O, CO2 and LLZO, while increasing the ionic conductivity of the electrolyte to 2.01×10−4 S·cm−1. The electrochemical window between the LLZHO and lithium metal reaches 4.7 V, which is 0.8 V higher than that of LLZO. The specific capacity of the 1st discharge of the all-solid-state batteries assembled with the LiFePO4 cathode at 0.1 C reaches 110 mAh·g−1. The coulombic efficiency reaches 99.2 % after 100 cycles, and the cycle retention rate is 65.8 %.
'%3e%3cpath fill='%23012169' d='M0 0v30h60V0z'/%3e%3cpath stroke='%23fff' stroke-width='6' d='m0 0 60 30m0-30L0 30'/%3e%3cpath stroke='%23C8102E' stroke-width='4' d='m0 0 60 30m0-30L0 30' clip-path='url(%23b)'/%3e%3cpath stroke='%23fff' stroke-width='10' d='M30 0v30M0 15h60'/%3e%3cpath stroke='%23C8102E' stroke-width='6' d='M30 0v30M0 15h60'/%3e%3c/g%3e%3c/svg%3e)
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)