Geometrically Non-Linear Bending Analysis of Piezoelectric Fiber-Reinforced Composite (MFC/AFC) Cross-Ply Plate Under Hygrothermal Environment

A finite element formulation for geometrically non-linear bending behavior of smart structures integrated with piezoelectric fiber-reinforced composite (AFC/MFC) layer acting as distributed actuator is presented in this article. The formulation of this hygro-thermo-electro-mechanical coupled problem is based on the first-order shear deformation theory (FSDT) and the von Kármán type geometric non-linearity. Resulting non-linear algebraic governing equations are linearized by Newton–Raphson iterative method. A developed finite element formulation is initially solved for validation and comparison with existing results. A wide variety of numerical examples considering cross-ply laminated substrates subjected to combined mechanical, hygrothermal and electrical loads are presented. The effect of piezoelectric fiber orientation in an actuator to counteract non-linear deflections is analyzed.     

基于MFC和 UG的汽轮机叶片工装参数化设计系统的研究

通过对UG二次开发工具及其工作原理的研究和分析,以及对汽轮机叶片工装的三维模型进行参数化设计和研究,介绍了利用VC 操纵UG零件族进行零件参数化设计原理,给出了在VC 编译环境下使用MFC 开发UG 应用程序的方法、步骤及界面实现技术,并以某汽轮机叶片工装为例详细介绍了参数化设计中的关键技术.该三维参数化设计方法不仅可以应用于汽轮机叶片工装,也可以应用于其它一些典型非标准结构件的参数化设计,可大大提高产品设计品质与速度.     

用ObjectARX开发AutoCAD2004应用程序

与以前版本相比，AutoCAD2004在用户界面、性能、功能等各方面都有较大的改进和完善，从而使AutoCAD上升到一个新的台阶。本文介绍了AutoCAD2004的开发环境，0bjectARX开发工具的功能和特点，并给出了具体实例。     

UG软件二次开发中MFC调用方法研究

探讨了UG二次开发工具UG／OpenAPI和UG／OpenMenuScript,鉴于UG应用开发中存在的问题,提出了在UG／OpenAPI中使用MFC的实现方法,并通过一个完整的例子说明了利用UG／OpenAPI、MFC及MenuScript联合开发CAD系统的方法。     

微生物燃料电池阳极材料的修饰研究进展

简要介绍了微生物燃料电池以及微生物燃料电池阳极材料,分别从碳纳米管、导电聚合物、石墨烯、金属及金属离子、中介体以及复合材料等方面介绍了目前微生物燃料电池阳极材料修饰的研究进展,最后展望了微生物燃料电池的应用前景。     

面向结构形状控制的驱动器结构参数与控制电压协同优化设计

飞机翼面结构形状的控制设计是提高飞机性能的关键技术。本文以压电纤维复合薄膜（Microfiber Composite,MFC）为驱动器,研究了协同优化设计MFC驱动器结构参数与控制电压以使飞机翼面结构具有理想形状的方法。以MFC的电极宽度、电极指间距、MFC厚度、压电陶瓷体积分数等驱动器结构参数以及控制电压为设计变量,以控制偏差最小为优化目标,以驱动器的击穿电压为约束,建立了驱动器结构参数与控制电压协同优化设计的模型;通过分析MFC驱动器结构参数对驱动性能的影响,给出了最优的驱动器结构参数;针对类似机翼翼面形状的平板扭转型面,给出了驱动器结构参数与控制电压协同的最优控制设计。设计结果表明：对于扭转变形,多个不同控制电压控制的型面均方差是相同控制电压控制均方差的45%,分析结果验证了本文所建立的协同优化设计方法的有效性。     

基于 MFC 驱动器的飞机翼面结构参数控制设计

针对飞机翼面结构存在翼面回弹量小和翼面变形量大的问题,提出基于 MFC 驱动器的飞机翼面结构参数控制设计方法。首先,对 MFC 驱动器进行介绍,了解其运行原理,并在该驱动器的帮助下简化机翼整体参数计算量;其次,构建机翼的平面有限元模型,并将平面有限元模型进行拉伸,生成立体的机翼结构,实现飞机翼面结构参数控制。实验结果表明,所提方法的翼面回弹量大、翼面变形量小、参数控制效果好及控制误差较小。     

Application of iron-based cathode catalysts in a microbial fuel cell

Catalysts for the oxygen reduction reaction (ORR) in a microbial fuel cell (MFC) were prepared by the impregnation on carbon black of Fe^II acetate (FeAc), Cl–Fe^III tetramethoxyphenyl porphyrin (ClFeTMPP), and Fe^II phthalocyanine (FePc). These materials were subsequently pyrolyzed at a high temperature. The ORR activity of all Fe-based catalysts was measured at pH 7 with a rotating disk electrode (RDE) and their performance for electricity production was then verified in a continuous flow MFC. Catalysts prepared with FeAc and pyrolyzed in NH₃ showed poor activity in RDE tests as well as a poor performance in a MFC. The ORR activity and fuel cell performance for catalysts prepared with ClFeTMPP and FePc and pyrolyzed in Ar were significantly higher and comparable for both precursors. The iron loading was optimized for FePc-based catalysts. With a constant catalyst load of 2 mg cm⁻² in a MFC, the highest power output (550–590 mW/m²) was observed when the Fe content was 0.5–0.8 wt%, corresponding to only 0.01–016 mg Fe/cm². A similar power output was observed using a Pt-based carbon cloth cathode containing 0.5 mg Pt/cm². Long-term stability of the Fe-based cathode (0.5 wt% Fe) was confirmed over 20 days of MFC testing.     

Synergistic interaction of biocatalyst with bio-anode as a function of electrode materials

Comprehensive study was performed to understand the synergistic interaction between the biocatalyst and anode in terms of electron discharge (ED) pattern and microbial growth by varying electrode (bio-anode) materials viz., graphite, aluminum, brass, copper, nickel and stainless steel. Experiments were performed in bio-electrochemical cell consisting of three electrodes (bio-anode as working electrode, carbon rod as counter electrode and Ag/AgCl(S) as reference electrode) employing anaerobic mixed culture as anodic biocatalyst. Voltammetric and chronoamperometric analysis were used to enumerate the ED and redox reactions. Presence of higher microbial population and dominance of Gram positive bacteria with higher ED supported graphite function as a good bio-anode material. Nickel and stainless steel showed higher ED after graphite associated with dominance of Gram positive bacterial population. Although higher ED was noticed with brass, metal oxidation and decrement in ED with time doesn’t support its function as bio-anode. In spite of higher ED than nickel and stainless steel, aluminum and copper showed significant metal oxidation leading to change in both physical and electrochemical properties along with dominant growth of Gram negative bacteria. This study gives a comprehensive idea on biocatalyst interaction with anode in extracellular electron transfer which is important in improving the anode performance. Juxtaposing the results, it can be deduced that the outcome of the present study can be extended to all bio-electrochemical systems including microbial fuel cell (MFC).     

6kV厂用电源快切装置误动原因分析及处理

厂用电源的快速切换技术近年来在大型发电机组厂用电系统中运用日臻完善和成熟,显示出它对确保机组稳定运行的优越性,并已在生产实际中积累了丰富的运行经验。分析了平顶山某电厂应用的2种快速切换装置的原理和使用中出现的问题及解决方法,提出了解决的思路。