Tungsten‐Based Materials for Lithium‐Ion Batteries

Lithium‐ion batteries are widely used as reliable electrochemical energy storage devices due to their high energy density and excellent cycling performance. The search for anode materials with excellent electrochemical performances remains critical to the further development of lithium‐ion batteries. Tungsten‐based materials are receiving considerable attention as promising anode materials for lithium‐ion batteries owing to their high intrinsic density and rich framework diversity. This review describes the advances of exploratory research on tungsten‐based materials (tungsten oxide, tungsten sulfide, tungsten diselenide, and their composites) in lithium‐ion batteries, including synthesis methods, microstructures, and electrochemical performance. Some personal prospects for the further development of this field are also proposed.     

新型捷联惯性测量装置标定测试系统的设计

为了提高捷联惯性测量装置(SIMU)的测量精度,在使用前必须对其进行标定,以确定SIMU模型方程的参数及其标定后的性能指标;为此设计了一种新型SIMU标定测试系统,使之可以对SIMU进行全温度范围内的标定与研究;在简要介绍了测试系统的组成、功能之后,详细叙述了SIMU标定测试单元的硬件设计与实现及速率试验时测量误差的修正方法;试验表明,该测试系统功能完善,运行稳定,操作方便,可维护性好,已成功地用于SIMU的标定与研究.     

页岩气旋转式井壁取心器转向机构设计与优化

转向机构作为页岩气旋转式井壁取心器的连接转向装置,其性能决定了取心器的过弯通过能力.鉴于此,设计了一种新型转向机构.该机构中心由一个胡克铰链连接,四周设置4组由移动副和弹簧连接的球面副;利用拆杆法建立了转向机构各零件的静力学平衡方程,确定了转向机构的工作空间,建立了取心器过弯能力与水平井曲率半径的函数关系;以通过能力最...     

过渡金属碳化物的催化研究进展

过渡金属碳化物作为一种催化新材料得到了人们广泛的关注,在催化加氢、脱氢、脱硫(HDS)、脱氮(HDN)和重整等方面,表现出优良的催化活性和选择性.综述了碳化钒、碳化钼、碳化钨、碳化铁、碳化钛等碳化物的催化性能和碳化物在各个反应中的催化机理的研究进展.     

AlGaN/GaN HEMT 小信号模型提取方法的改进

The accurate extraction of AlGaN/GaN HEMT small-signal models, which is an important step in largesignal modeling, can exactly reflect the microwave performance of the physical structure of the device. A new method of extracting the parasitic elements is presented, and an open dummy structure is introduced to obtain the parasitic capacitances. With a Schottky resistor in the gate, a new method is developed to extract Rg. In order to characterize the changes of the depletion region under various drain voltages, the drain delay factor is involved in the output conductance of the device. Compared to the traditional method, the fitting of S 11 and S 22 is improved, and fT and fmax can be better predicted. The validity of the proposed method is verified with excellent correlation between the measured and simulated S-parameters in the range of 0.1 to 26.1 GHz.     

记忆存储式汽车后视镜疲劳测试系统的设计

介绍了一种基于单片机的记忆存储式汽车后视镜疲劳测试系统的设计。利用C8051F340单片机作为数据采集和控制电路的主要部件,控制继电器驱动后视镜电机运动。采用异步串行通讯方式与上位机实现数据传输和控制,实现PC机与多台单片机通讯。介绍了测试系统的硬件设计并给出了单片机和上位机的软件设计。实验测试表明,该测试系统能满足长时间的疲劳测试工作,其稳定性、可靠性和测试效果能够满足后视镜质量检测对系统的要求。该测试系统已在汽车后视镜质量检测中心应用,运行良好,性能稳定可靠。     

提高本科毕业论文质量的途径探讨

毕业论文是大学课程设置中的重要组成部分,然而由于种种原因,我国高校的本科毕业论文质量存在不同程度的下降.面对这种状况,本文从日常科研训练和加强毕业论文全程监控等两个方面来阐述提高论文质量的各种途径.     

基于GSM模块的光线检测系统设计

开关量信号采样是工业过程领域中一种常见的数据采集技术。本系统由单片机控制系统、显示模块、发送模块和光线检测模块等组成,采用AT89S51单片机作为系统的控制器,实现对开关量信号的采集和处理,并通过TC35 GSM模块发送处理后的信息。系统工作正常,运行稳定。