井下电机车直流供电系统的技术改造

阐述了老矿山井下电机车直流供电系统的诸多弊病。及采取大容量整流设备、放射式集中供电的技改措施和取得的良好效果。     

智能气门电镦机人机交互及串行通讯程序

介绍了智能气门电镦机的数据显示和命令输入的人机界面(HMI)和实现电镦机实时控制功能的下位计算机之间利用RS232串行接口的通讯程序的编写，以及实现硬件定时的原理和方法．实践证明，该系统人机界面美观、实时性能可得到保证，符合气门电镦的工艺要求．     

地质勘探工程网络电测仪系统研究

使用SOC单片机Cygnal C8051和数控恒流源、LCD等组成系统主机，使用2051单片机和微型继电器组成电极工作分站，主机与电极工作分站之间使用高速RS-485连接。通过主机对电极工作分站的控制，实现电法勘探中电阻率法的二极、三极、四极、微分、偶极、复合多极等方法的任意时空组合的数据采集，为进行电阻率、激电值归位计算，反演地下电性层的构造形态提供充分的数据。     

应用微机绘制电位─pH图分析氯氧化铋精矿提纯工艺

应用微机绘制了Ｂｉ，Ｆｅ，Ａｓ，Ｓｂ，Ｐｂ等元素的Ｍｅ－Ｃｌ－Ｈ２Ｏ系和Ｍｅ－ＮＯ３－－Ｈ２Ｏ系的Ｅｈ－ｐＨ图．在对Ｅｈ－ｐＨ图分析的基础上，制定了提纯氯氧化铋精矿，制取药用次硝酸铋的新工艺．     

PHEV驱动系统结构分析与仿真研究

对插电式混合动力汽车(PHEV)的串、并联驱动系统结构进行分析.以中型SUV为例,确定了整车动力系统参数和控制策略;使用Advisor进行仿真.仿真结果表明:在控制策略和工况既定的前提下,当所用电池容量较小时,并联PHEV总体性能优于串联PHEV;电池容量增加后,串联PHEV表现出良好的适应性.     

静止条件下轨道炮电流分布特征仿真

目前电磁轨道炮研究的主要问题之一是发生在轨道和电枢之间的放电烧蚀。造成烧蚀的主要原因是轨道和电枢中电流分布的不均匀性。针对静止条件下5种典型的轨道-电枢结构,采用Ansoft12有限元分析软件,对比仿真分析了电流密度分布,结果表明:跑道截面轨道-马鞍体结构电枢的轨道炮具有最均匀的电流密度分布现像;矩形截面轨道-长方体结构电枢的轨道炮具有最大的不均匀电流分布特征。上述结论对抑制放电烧蚀、改善刨削和延长轨道使用寿命等方面有重要参考意义。     

Achieving both high electromechanical properties and temperature stability in textured PMN-PT ceramics

Textured piezoelectric ceramics, such as textured Pb(Mg_1/3Nb_2/3)O₃-PbTiO₃ (PMN-PT) ceramics, have attracted considerable attention from both academia and industry, as they possess crystal-like piezoelectric properties, high composition homogeneity, and low manufacturing cost. However, the main difficulty with the textured piezoelectric ceramics is the presence of BaTiO₃ (BT) templates, which greatly reduces their piezoelectricity and phase transition temperature. Thus, it is highly recommended to fabricate textured piezoelectric ceramics using as few templates as possible. Here, we successfully fabricated high-quality <001>-textured PMN-28PT ceramics (texturing degree of 99%) by using an extremely small amount of BT templates (1 vol.%) with the help of CuO/B₂O₃ sintering aids. The textured PMN-28PT ceramic exhibits 80% piezoelectric coefficient (d₃₃ ∼ 1200 pC/N), 96% electromechanical coefficient (k₃₃ ∼ 88%) and the same temperature stability (T_rt ∼ 100, T_c ∼ 150°C) when compared to its single crystal counterpart. In addition, by using an alternating current electric field poling (AC-poling), the piezoelectric coefficient d₃₃ and dielectric permittivity ε₃₃ of the textured PMN-28PT ceramics were further enhanced around 5–8%. It is believed that the advantages of high electromechanical properties, low cost, and easy mass production of textured PMN-28PT ceramic will make it a promising candidate for advanced electromechanical devices.     

电场对竖直微槽润湿及毛细流动特性影响

竖直微槽群毛细结构广泛应用在重力热管、蒸发器等散热设备内,但受重力等因素影响易达到毛细极限。引入电场的主动强化方式来提高竖直微槽的毛细极限,并通过实验和建立数学模型研究电场对竖直微槽内液体润湿及毛细流动特性的影响。结果表明,电场可以提高竖直微槽内液体润湿高度,当电场为5.0 kV时与无电场时相比,润湿高度强化比可达到30.0%。同时,电场作用下流体在微槽道内的毛细润湿流动呈分段效应：润湿流动初期,润湿高度与时间的1/2次方呈线性关系,即h-t^1/2,润湿速率与润湿高度的倒数呈线性关系,即v-1/h;润湿流动中后期,润湿高度与时间的1/3次方呈线性关系,即h-t^1/3,润湿速率与润湿高度平方的倒数呈线性关系,即v-1/h²,且润湿速率随时间呈下降趋势。     

High-strength Ti2AlN ceramics prepared by pulse electric current sintering based on powders synthesized by molten salt method

Ti₂AlN powders were synthesized through molten salt method and re-calcination process using TiH₂, Al and TiN powders as raw materials at 1100 ℃. The composition of final composite was directly influenced by the initial Al and TiH₂ content in the starting mixture. The purity of the synthesized Ti₂AlN powder could reach 97.1 wt% when the Al molar ratio was 1.05. Then high strength Ti₂AlN ceramics were successfully prepared in different modes, including two forms of pulse electric current sintering (PECS/SPS) and hot-pressing sintering (HP). A record-high flexural strength of 719 MPa was obtained for the PECS/SPS with an electrical insulating die (PECS/SPS II) sintered sample, based on the synthesized powder in which the initial molar ratio of Al was 1.1. The sintering behaviors in various modes were analyzed, confirming the shrinkage of particles starting at lower temperature in PECS/SPS II. The density, microstructure, Vickers hardness and elastic modulus of sintered ceramics were also investigated. Therefore, the present work provided the new methods about powder preparation and ceramic sintering of Ti₂AlN, making it possible to be used as high strength structural ceramics.     

[分布式驱动电动汽车动力学控制]基于多Agent的电动汽车底盘智能控制系统框架

To solve the problems that flexibility and scalability limitations of the traditional integrated chassis control frameworks and the traditional vehicles chassis control system was not suitable for distributed in-wheel motors drive electric vehicles, an intelligent chassis dynamic control system framework was proposed based on multi-Agent for four-wheel independent driving electric vehicles. And the functions and interrelations of layers were analyzed. Taking direct yaw-moment control Agent of underlying control layer as an example, the controller Agent model was designed. In the co-simulation environment including MATLAB/Simulink and Carsim, simulation tests were conducted with the conditions of front wheel steering angle step input. Simulation results show that the controller Agent model may achieve the desired objectives of dynamic control and improve the performances of lateral handling stability effectively, which lays the foundation for the proposed control framework.