以MOFs为模板制备TMO/C复合材料 在锂离子电池中的应用

商用负极材料石墨理论比容量较低,无法满足市场的需求,发展具有更高比容量的负极材料来替代石墨至关重要.介绍了过渡金属氧化物(TMO)和金属-有机框架(MOFs)的特点及锂离子电池负极材料性能改进的方法,综述了以MOFs为前驱体制备TMO/C复合材料作为锂离子电池负极的优点及研究进展,并对此类负极材料的发展趋势进行了总结与展望.     

Self-excited vibration problems of maglev vehicle-bridge interaction system

The self-excited vibration problems of maglev vehicle-bridge interaction system were addressed, which greatly degrades the stability of the levitation control, decreases the ride comfort, and restricts the cost of the whole system. Firstly, the coupled model containing the quintessential parts was built, and the mechanism of self-excited vibration was explained in terms of energy transmission from levitation system to bridge. Then, the influences of the parameters of the widely used integral-type proportion and derivation（PD） controller and the delay of signals on the stability of the interaction system were analyzed. The result shows that the integral-type PD control is a nonoptimal approach to solve the self-excited vibration completely. Furthermore, the differential-type PD controller can guarantee the passivity of levitation system at full band. However, the differentiation of levitation gap should be filtered by a low-pass filter due to noise of gap differentiation. The analysis indicates that a well tuned low-pass filter can still keep the coupled system stable.     

轮胎在侧向力、纵向力联合工况下的神经网络模型

建立了轮胎在侧向力、纵向力联合工况下的神经网络模型，分析了不同训练方法对模型精度的影响。通过对轮胎实测值与神经网络预测值的对比表明，轮胎神经网络模型的精度能满足工程要求，BP前馈神经网络可有效地应用于车辆轮胎特性的数学建模。     

基于Pro/E的远程零件参数化设计系统研究

提出了一种远程设计机械零部件的新方案.利用VC+ +对Pro/E进行二次开发,将开发的程序封装成COM组件,利用Pro/E进行参数化建模,通过ASP技术调用COM组件实现远程参数化设计.以斜齿圆柱齿轮为例说明机械零部件远程设计系统的实现过程.     

A practical robust nonlinear controller for maglev levitation system

In order to explore the precise dynamic response of the maglev train and verify the validity of proposed controller, a maglev guideway-electromagnet-air spring-cabin coupled model is developed in the first step. Based on the coupled model, the stresses of the modules are analyzed, and it is pointed out that the inherent nonlinearity, the inner coupling, misalignments between the sensors and actuators, and external disturbances are the main issues that should be considered for the maglev engineering. Furthermore, a feedback linearization controller based on the mathematical model of a maglev module is derived, in which the nonlinearity, coupling and misalignments are taken into account. Then, to attenuate the effect of external disturbances, a disturbance observer is proposed and the dynamics of the estimation error is analyzed using the input-to-state stability theory. It shows that the error is negligible under a low-frequency disturbance. However, at the high-frequency range, the error is unacceptable and the disturbances can not be compensated in time, which lead to over designed fluctuations of levitation gap, even a clash between the upper surface of electromagnet and lower surface of guideway. To solve this problem, a novel nonlinear acceleration feedback is put forward to enhancing the attenuation ability of fast varying disturbances. Finally, numerical comparisons show that the proposed controller outperforms the traditional feedback linearization controller and maintains good robustness under disturbances.     

废旧三元锂离子电池正极有价金属回收进展

随着锂离子电池在新能源汽车等多领域的广泛应用,废旧三元锂离子电池(LIBs)的数量不断增多,LIBs中有价金属的回收资源化成为了全球热点话题。综合阐述了近几年较为常用的LIBs回收方法,主要概括为火法冶金工艺、湿法回收工艺、火法-湿法联合浸出工艺。其中火法-湿法联合浸出工艺因其回收率高、过程简单、环境污染小、成本较低具有较大的工业发展前景。     

新型相变储能材料研究进展

介绍了相变材料的种类、特点以及储能机理,重点论述了新型相变材料的研究发展,对于复合相变材料和胶囊化相变材料做了较为详细的说明,概括了相变材料的主要研究方向.     

空调方案优化与CAD

本文对常用制冷和空调方式的几个主要因素进行量化，提出因素权重系数概念，以反映空调方案设计阶段的客观条件和主观设计思想。运用计算机辅助设计，所选方案可行、优越     

吡咯烷-2-酮化合物的合成

以常见的苯乙酮为起始原料，通过盐酸羟胺的加成形成肟，部分肟在钯碳/氢气的条件下直接还原以较好产率得到相应伯胺；另一部分难以直接还原的肟，通过二苯基氯化膦的修饰，随后用硼氢化钠还原、氯化氢脱保护可得到一系列相应的伯胺。最后伯胺在碱性条件下与4-氯丁酰氯进行环化反应，以良好产率得到广泛用于生物活性物质的N-(1′-芳基烷基)-2-吡咯烷酮化合物。目标产物结构通过¹HNMR、¹³CNMR、HRMS-ESI等方式表征。