频显式高频函数信号发生器的设计及其实现

文章介绍利用MAX038和运算放大器设计的函数信号发生器，它能够直接产生正弦波，三角波，方波，且波形失真小，稳定度比较好。     

3DS MAX课程改革的探讨

3DS MAX的应用非常广泛,但是学生的学习效果不是很好。本文通过教学内容、教学方式和考试环节三个方面对3DS MAX课程的改革进行了阐述,以期对今后该课程的讲授起到很好的帮助。     

正弦信号发生器的设计

设计的正弦信号发生器参加了2005年全国大学生电子设计大赛,获得吉林省级设计三等奖。该正弦信号发生器是通过凌阳公司生产的SPCE061A单片机对MAX038芯片的控制来实现的。正弦波输出频率范围为1kHz～10MHz;具有频率设置功能,且频率步进为100Hz;输出信号频率稳定度优于10-4;输出电压幅度在50Ω负载电阻上的电压峰-峰值Vopp≥1V;用示波器观察时无明显失真。     

船体三维模型数据的转换和处理技术

为了实现船体虚拟装配过程仿真,通过数据转换和处理技术,将TRIBON模型数据转换到虚拟仿真平台.论述了将TRIBON绘制的船体模型数据向3DS MAX工作环境转换的方法,着重介绍了在3DS MAX环境下对模型进行相应处理以及将模型数据导入VRPlatform仿真平台的方法.     

采用MAX038的信号发生器的设计

信号发生器在电路、电子实验和设备检测中具有十分广泛的用途。随着电子技术的迅速发展,新一代函数信号发生器MAX038能产生三角波、方波和正弦波,具有输出性能稳定,失真度小等特点。     

可编程单次脉冲发生器的教学实验

介绍了一个数字系统综合设计实验：可编程单次脉冲发生器的设计与实现。该脉冲发生器可在输入按键的控制下,产生单次的脉冲,脉冲的宽度可由8位的输入数据控制。实验以FPGA为硬件基础,以MAX＋plusⅡ为软件工具开发完成。实验不仅体现了数字系统设计实验课程的综合训练目标,要求学生能综合、灵活应用VerilogHDL语言,掌握多层次结构系统设计方法、Top_down设计思想和FPGA开发方法等理论知识,并且与工程实际结合紧密。所开发的系统具有很大的实用价值,是一个值得推广的典型教学实验。     

Density Functional Theory Study of Mn+1AXn Phases: A Review

M_n+1AX_n phases (MAX phases for short with M: transition metal, A: A group elements, X: C or N, and n = 1–3) have attracted considerable attention due to the unique combination of the ceramic- and metal-like properties. The density functional theory (DFT) has emerged as a powerful theoretical approach that complements experimental testing and serves as a predictive tool in the identification and characterization of MAX phases. After the beginning with a brief introduction of the MAX phase and DFT, we review the DFT study on this class of materials, including crystal structure, electronic structure, point defects, lattice dynamics, and related properties, phase stability, compressibility, and elastic properties. Comparison between the theoretical values and available experimental ones shows that they are in decent agreement for most part, especially in the lattice constants, elastic properties, and compressibility. This article is concluded with an outlook of future research on DFT study of MAX phases, major challenges to be met and possible solutions in some cases.     

固溶体MAX相(Ti0.5V0.5)3AlC2的制备及其对MgH2储氢性能的催化影响

通过无压烧结法制备了固溶体MAX相(Ti_(0.5)V_(0.5))_3AlC_2,研究了其添加对MgH_2储氢性能的影响。结果发现,固溶体MAX相(Ti_(0.5)V_(0.5))_3AlC_2中的Ti和V元素通过协同作用,呈现出更高的催化活性。添加质量分数10%(Ti_(0.5)V_(0.5))_3AlC_2的MgH_2样品的起始放氢温度为230℃,较原始MgH_2降低了60℃。在275℃下等温放氢,(Ti_(0.5)V_(0.5))_3AlC_2添加样品的放氢速率可达0.35%·min~(-1),是原始MgH_2样品的4倍左右。此外,完全放氢后的MgH_2-10%(Ti_(0.5)V_(0.5))_3AlC_2样品在150℃、5 MPa氢压下,可在60 s内吸收4.7%的氢。计算显示,MgH_2-10%(Ti_(0.5)V_(0.5))_3AlC_2样品的表观活化能为79.6 kJ·mol~(-1),较原始MgH_2(153.8 kJ·mol~(-1))降低了48%,这是MgH_2放氢性能得到改善的主要原因。     

无人机虚拟仿真三维交互控制模型的设计与实现

介绍了如何利用Pro/E、3DS MAX及Cult 3D软件设计制作无人机虚拟仿真三维交互控制模型,实现无人机的精确建模、动态模拟和交互控制.     

Microstructure and phase transformation of Ti3AC2 (A = Al,Si) in hydrofluoric acid solution

In this paper, Ti₃AC₂ (A = Al, Si) were prepared by pressureless argon shielding synthesis technique. The microstructure and phase transformation of as‐prepared Ti₃AC₂ (A = Al, Si) in hydrothermal hydrofluoric acid (HF) solution were investigated systematically. Results showed that the obtained Ti₃AlC₂ and Ti₃SiC₂ were closely aligned layered structure. In hydrothermal HF solution, Al or Si element was preferentially etched from the layered structure, inducing obvious transformation of microstructure and phase composition. For Ti₃AlC₂, Al atoms diffused out of the structure and reacted with HF to form AlF₃•H₂O, which induced the rearrangement of the Ti and C atoms, and finally resulted in the formation of TiC_x cubic phase. With the hydrothermal temperature and reaction time increasing, the TiC_x phase gradually disappeared and the grain size of AlF₃•H₂O gradually increased. When Ti₃SiC₂ was immersed in hydrothermal HF solution, the main products were TiC and SiC. Interestingly, with the hydrothermal treatment temperature and reaction time increasing, TiC gradually disappeared, while SiC nearly kept unchanged. This can be explained that SiC was covalently bonded carbide, while TiC was metallically bonded, having relatively weak bond energy and consequently being unstable in hydrothermal HF solution.