电子设计软件Altium Designer的多通道设计应用

学习好Altium Designer对于电子工程师的设计能力的提高有着十分重要的作用。本文介绍了Altium Designer多通道设计应用的背景、功能,以及在电路图和电路板设计中的实现方法,并给出了一个设计实例。

基于区块链技术的航班协同运行保障系统架构设计

在民航领域的航班协同运行保障过程中,传统的信息共享方式存在数据外泄、记录篡改、数据难追溯、数据难监管、隐私难保护等问题,提出一种由机场、航空公司、空管以及地服公司协同参与的区块链架构——航班信息共享链架构。根据航班运行过程中的实际流程与需求,从层次结构、网络结构、访问事件监管机制与多通道设计四个方面设计该架构,进而形成一种新型航班协同运行保障系统架构。实验结果表明,该架构不仅能够满足航班协同运行保障系统需求,还减少了单节点存储容量,更好地实现了航班协同保障参与方之间的动态信息共享。

具有无穷多共存类吸引子的保守混沌系统同步控制

提出了一个三维的保守混沌系统,在MATLAB中绘制它的类吸引子图、相图、Lyapunov指数图及分析它的动力学特性,可以验证该系统是一个保守混沌系统。之后对系统进行正弦项变换,得到了一个新的三维系统,对变换后的系统进行分析,可以验证其也是保守混沌系统,且具有无穷多共存类混沌吸引子。最后,构造了一种多通道误差系统及同步控制方案设计,以变换后的具有无穷多共存类吸引子的系统为研究对象进行误差及同步控制设计。仿真结果验证了多通道误差系统及同步控制方案的有效性。

Exergy Analysis of Single and Multi-Step Thermal Processes

The present paper introduces the concepts of exergy and treats it applications to analysis of the gain in exergy efficiency between one-step and multi-step thermal processes. The analysis, which is carried out with the Excel-based SEPE program, is exemplified with the comparison between single-step and two-steps heat pump setup for providing heat to a floor heating system and for domestic hot water. The paper discusses the use of the concept of exergy efficiency as a measure of success for design of a heat pump application and how the use of information on exergy destruction and temperature levels in different parts of the system add a new perspective to the analysis and the evaluation of the system performance. The paper shows how this information can be used to improve the system configuration and also the operation of the system for given boundary conditions. This is especially useful when the energy from the low temperature sources can be utilized at different temperature or quality levels such as for space heating and domestic hot water.

Design of 3D Active Multichannel Silicon Neural Microelectrode

To find a design method for 3D active multichannel silicon microelectrode, a microstructure of active neural recording system is presented, where two 2D probes, two integrated circuits and two spacers are microassembled on a 5 mm×7 mm silicon platform, and 32 sites neural signals can be operated simultaneously. A theoretical model for measuring the neural signal by the silicon microelectrode is proposed based on the structure and fabrication process of a single-shank probe. The method of determining the dimensional parameters of the probe shank is discussed in the following three aspects, i.e. the structures of pallium and endocranium, coupled interconnecters noise, and strength characteristic of neural probe. The design criterion is to minimize the size of the neural probe as well as that the probe has enough stiffness to pierce the endocranium. The on-chip unity-gain bandpass amplifier has an overall gain of 42 dB over a bandwidth from 60 Hz to 10 kHz; and the DC-baseline stability circuit is of high input resistance above 30 MΩ to guarantee a cutoff frequency below 100 Hz. The circuit works in stimulating or recording modes. The conversion of the modes depends on the stimulating control signal.

Design of Time-Domain Equalizer in Elastic Wave Earth Channel

In low-frequency elastic wave through-the-earth communication system,because of multipath transmission caused by characteristics of the layered earth,the time domain equalizer is different from other wireless communication systems.A modified LMS algorithm of variable step size is proposed based on improvement of traditional LMS.On the base of principle and simulation analysis,the improved Least Mean Square(LMS)algorithm is analyzed and the performances are compared between the improved LMS algorithm and traditional LMS algorithm.In the improved algorithm,the contradiction between convergence speed and the steady-state error is considered at the same time.Therefore,the improved algorithm has good convergence properties and channel-tracking performance.

Study on the Influence of Structural Parameters of Multi-channel Cylinder Dryer on Heat Transfer Performance

An approach to design multi-channel cylinder dryer was proposed. The heat transfer performance and flow characteristic under various structural parameters were analyzed. First, an experiment was designed and set up to measure the condensing heat transfer coefficient and the pressure drop in order to ,~erify the applicability of the Cavallini＇s correlation. Then, the relationship among the count of channels, aspect ratio, spacing ratio, width, height and hydraulic diameter of a channel was given. Finally, the correlation of condensing heat transfer and the homogeneous model was introduced in order to observe the heat transfer performance and flow characteristic of the multi-channel cylinder dryer affected by different structures. The study reveals that the structural parameters including count of channels, aspect ratio, spacing ratio of a channel dramatically influence the condensation heat transfer coefficient and frictional resistance of the steam. Based on the selected paper machine, it is suggested that the overall performance of the multi-channel cylinder dryer is best if the count of channels is 150-200, the aspect ratio is 1 ： 3 and the spacing ratio is 1 ： 1-1 ： 3.