Hierarchical Ni-BDC coated FeOOH nanosheets: A coordination tuning synergistic electrocatalyst with enhanced activity for water oxidation

Hierarchical composites represent a class of efficient electrocatalysts for renewable energy storage and conversion technologies owing to the porous structure and additional exposure of metal sites. Herein, a Ni-based metal organic frameworks (MOFs) (marked as Ni-BDC, BDC stands for 1,4-benzenedicarboxylic acid) nanosheet is successfully fabricated on hydroxyl iron oxide (FeOOH) array with carbon fiber cloth (CFC) as substrate. Benefit from the coordination tuning synergistic effect of the distinct chemical composition and the hierarchical structure for fast mass transportation, the as-obtained FeOOH@Ni-BDC illustrates excellent catalytic ability for electrochemical water oxidation with low overpotential of 270 mV to reach 10 mA/cm² current and good durability in alkaline electrolyte. The novelty of this work lies in the modulation of electronic structure of the FeOOH with Ni-BDC through coordination effect to enhance the activity of the hierarchical composite electrocatalyst. This work is expected to guide the preparation of efficient electrocatalyst for new type alternative energy sources exploitation in near future.     

Study on maximum power point tracking of photovoltaic array in irregular shadow

Traditional maximum power point tracking (MPPT) methods can hardly find global maximum power point (MPP) because output characteristics curve of photovoltaic (PV) array may have multi local maximum power points in irregular shadow, and thus easily fall into the local maximum power point. To address this drawback, Considering that sliding mode variable structure (SMVS) control strategy have such advantages as simple structure, fast response and strong robustness, and P&O method have the advantages of simple principle and convenient implementation, so a new algorithm combining SMVS control method and P&O method is proposed, besides, PI controller is applied to reduce system chattering caused by switching sliding surface. It is applied to MPPT control of PV array in irregular shadow to solve the problem of multi-peak optimization in partial shadow. In order to verity the rationality of the proposed algorithm, the experimental circuit is built, which achieves MPPT control by means of the proposed algorithm and P&O method. The experimental results show that compared with the traditional P&O algorithm, the proposed algorithm can fast track the global MPP, tracking speed increases by 60% and the relative error decreased by 20%. Moreover, the system becomes more stable near the MPP, the fluctuations of output power is greatly reduced, and thus make full use of solar energy.     

Covariance matrix adaptation evolution strategy based design of fixed structure robust H∞ loop shaping controller

This paper proposes the application of Covariance Matrix Adaptation Evolution Strategy (CMA-ES) in fixed structure H_∞ loop shaping controller design. Integral Time Absolute Error (ITAE) performance requirement is incorporated as a constraint with an objective of maximization of stability margin in the fixed structure H_∞ loop shaping controller design problem. Pneumatic servo system, separating tower process and F18 fighter aircraft system are considered as test systems. The CMA-ES designed fixed structure H_∞ loop-shaping controller is compared with the traditional H_∞ loop shaping controller, non-smooth optimization and Heuristic Kalman Algorithm (HKA) based fixed structure H_∞ loop shaping controllers in terms of stability margin. 20% perturbation in the nominal plant is used to validate the robustness of the CMA-ES designed H_∞ loop shaping controller. The effect of Finite Word Length (FWL) is considered to show the implementation difficulties of controller in digital processors. Simulation results demonstrated that CMA-ES based fixed structure H_∞ loop shaping controller is suitable for real time implementation with good robust stability and performance.     

气压仪器检定装置的升级改造

文章针对气压检定装置在使用中存在的一些问题,会同厂家对其进行了升级改造。介绍了改造后的气压检定装置的设计原理、软件和硬件设计以及技术指标等,新装置集成了目前先进的计量设备及技术,编写相应的程序软件升级改造而成。可广泛适用于气象部门空盒气压表、自动站气压传感器以及部分数字压力计的计量检定工作,实现气压检定工作的自动化,提高检定数据的准确性和可靠性,并有效提高检定的工作效率。     

基于ＰＩＤ控制算法的直流微网容错控制方法研究

构建直流微网容错控制对象模型，调节直流微电网的输出回路参数；以输出功率、直流微网的 参考电压、弱电网下系统惯性响应特征等为约束参量，构建直流微网容错控制目标函数，在不同电网强度下 进行直流微网容错控制的参数自整定性调节，采用无功环比例积分控制方法进行直流微网容错寻优分析， 建立模糊 ＰＩＤ控制模型，采用变结构的模糊 ＰＩＤ控制方法进行直流微网容错控制过程中的自适应加权学习 和误差反馈调节，实现直流微网容错控制改进设计。仿真结果表明，采用该方法进行直流微网控制的容错 性能较好，输出稳定性较强，具有较好的直流微网输出增益。     

浅谈焦炉煤气鼓风机高压变频调速控制系统的设计

本文对焦炉煤气加压控制系统进行了分析，在焦炉煤气加压机控制系统中运用变频调速技术对其进行改造，从而实现煤气加压机运转的自动调节，有效地稳定了焦炉煤气母管压力，保证了安全运行，并且达到节约能源的效果。解决了两台鼓风机并列运行，靠调节回流阀无法实现压力恒定这个始终困扰焦炉生产的难题。     

基于调谐频率与分频处理的高分辨率反演技术

讨论了基于调谐频率与分频处理的高分辨率反演技术，给出了方法的基本原理，即利用地震数据的调谐频率和分频处理分析，半定量地确定储层厚度，并将其作为地震反演的约束条件。方法的实现过程是：通过层状地质模型的地震正演模拟，建立不同主频子波时地层厚度与调谐频率的关系；利用地震资料时-频分析技术，实现地震资料分频处理；利用合成地震记录标定地震子波主频；利用分频处理结果，借助于调谐频率分析与调谐振幅分析，给出地震反演约束条件；利用反演算法消除地震子波影响，提高和拓展地震资料的频带范围，实现储层的高分辨率成像。普光地区的应用实例表明，调谐频率与分频处理的高分辨率反演方法无需对储层空间变化规律进行假设，适用于强非均质碳酸盐岩储层的高分辨率成像。     

包装件压力试验机计算机测控系统

针对YE-50包装件压力试验机落后的测控系统，提出一种基于压力和位移闭环控制的计算机测控系统。根据测得的压力、位移和设定值，通过模糊控制输出驱动伺服阀实现了压力试验时的恒速控制和堆码试验时的恒力控制。并实时显示力——位移及应力——应变曲线。文中还对模糊控制器的实验整定方法进行了探讨。     

基于MODBUS协议的激光雕刻切割系统HMI人机交互设备

近年来,国内激光雕刻切割控制器技术发展迅速,基于PC的传统控制器已相当成熟.为了显著提高工业生产效率,适应工业生产规模扩张的需要以及工业对系统稳定性要求的提高,目前国内几家专业运动控制器厂家已经实现了激光雕刻切割控制器的完全脱机运行.本文针对脱机控制器的需要设计一款人机交互设备,该设备采用AT89C55WD单片机为主控制器,采用标准的MODBUS协议实现HMI与脱机控制器的可靠通讯.     

浅谈在多节目码流复用与解复用中PID码的作用

文章简要阐述了PID码在多节目码流的复用与解复用中所起的作用。并运用PID码的原理来解释和解决在实际工作中碰到的PID码问题。