SVD-LMD联合降噪和TEO的滚动轴承故障诊断

针对随机噪声背景下滚动轴承局部损伤信息提取困难的问题，提出了一种奇异值分解（Singular value decomposition，SVD）和局部均值分解（Local mean decomposition，LMD）联合降噪，并结合Teager能量算子（Teager energy operator，TEO）的特征提取新方法。首先，利用SVD方法对滚动轴承故障振动信号进行处理，初步剔除背景噪声；然后，使用LMD方法分解降噪后的信号，依据相关系数指标筛分出敏感乘积函数（Product function，PF）并加以重构；最后，对重构的信号进行TEO解调分析，将解调谱中幅值突出的频率成分与故障特征频率理论值进行对比，提取故障信息。结果表明，该方法可有效提取轴承局部损伤的特征频率，最终实现故障诊断

Li ion intercalation charactersitic of gas coke

锂离子电池的研究与开发具有诱人的商业前景．以金属锂为负极的锂二次电池存在着充放电循环寿命短和使用安全性能差等诸多问题，解决的途径之一是采用嵌锂化合物替代金属锂作为负极材料．其中，以具有贮锂功能的碳素材料作为负极的锂离子电池，不仅具有较高的电容量和较长...A novel of carbon gas coke prepared from natural gas by thermoplasma technology has been studied. The cyclic voltametry and charge discharge test for the Li/gas coke cell demonstrated that this gas coke material has a good performance of the Li ion intercalation characteristic. X ray diffraction pattern of the gas cokeis showed that the structure of gas coke is similar to the graphite and collapsed from order to disorder during the charge discharge cycles. The gas coke electrode give rise to a new diffraction peak at a low angle after intercalating Li ion and a reversible capacity with 235 mAh/g is showed. The first charge discharge efficiency was about 58.3%.作者联系地址：中国科学院成都有机化学所Author's Address: Chengdu Institute of Organic Chem., Chinese Academy of Sciences,Chengdu 61004