In situ ceramic fillers of electrospun thermoplastic polyurethane/poly(vinylidene fluoride) based gel polymer electrolytes for Li-ion batteries

Gel polymer electrolyte films based on thermoplastic polyurethane (TPU)/poly(vinylidene fluoride) (PVdF) with and without in situ ceramic fillers (SiO₂ and TiO₂) are prepared by electrospinning 9 wt% polymer solution at room temperature. The electrospun TPU-PVdF blending membrane with 3% in situ TiO₂ shows a highest ionic conductivity of 4.8 × 10⁻³ S cm⁻¹ with electrochemical stability up to 5.4 V versus Li⁺/Li at room temperature and has a high tensile strength (8.7 ± 0.3 MPa) and % elongation at break (110.3 ± 0.2). With the superior electrochemical and mechanical performance, it is very suitable for application in polymer lithium ion batteries.     

轮胎式起重机转台结构的数值分析

在分析DLQ25轮胎式起重机起升机构工作时转台结构受力情况的基础上,对转台结构在载荷作用下的工作应力分布情况进行数值分析.根据转台结构在起吊工况下的动力学特性,结合实际情况建立有限元动力学模拟的载荷模型.运用有限元法分别模拟承受静载和动载的转台结构的应力分布情况,重点研究旋转支承法兰与盖板焊缝处环形区域(30°＜θ＜150°)的应力分布.有限元分析结果表明, 结构的应力分布主要集中于旋转支承法兰与盖板焊缝处,呈现出典型的双峰特征;而随着循环次数的增加,最大变形有明显累积.     

基于BP神经网络预测的微网系统dq轴谐波阻抗的主动测量策略

随着分布式电源的大量接入,微网系统的谐波阻抗测量更具有动态性和不确定性,对系统谐波阻抗的主动测量是谐波分析、滤波器设计等的重要基础。当分析微网系统的稳定性时,其dq轴谐波阻抗参数的获得显得至关重要。文章中对微网系统诺顿等效电路的dq轴谐波阻抗进行了理论的推导,建立了RL系统谐波阻抗模型。为了提高预测精度,文章引入了BP神经网络预测模型,介绍了其核心算法梯度下降原理,并建立了基于系统dq轴谐波阻抗的预测模型。然后为了得到不相关的注入谐波电流矢量以求解系统谐波阻抗矩阵,文章中介绍了旋转电流相量法,主动获得系统dq轴谐波阻抗。对微网系统dq轴谐波阻抗的测量和预测进行了仿真验证,其仿真结果证明了文章中所提策略的有效性。     

Adakitic rocks and destruction of the North China Craton:Evidence from experimental petrology and geochemistry

The general temporal-spatial consistency for the formation of adakitic rocks and lithospheric thinning in northern China provide a window to examine the processes and mechanism for the destruction of the North China Craton.With experimental petrology data,this paper demonstrates that the adakitic rocks in northern China are the products of partial melting of middle-to high-potassic metabasalts at the base of the lower continent crust.Based on the TiO2 solubility model,many adakitic rocks in Dabie,Jiaodong a...