基于ANSYS有限元法的电导率传感器分析

提出了一种结构简单的新型非接触电导率传感器。从原理出发,采用ANSYS有限元方法,通过建立有限元模型、定义材料属性、网格划分、设置边界条件、加载和求解等,得到了溶液电导率分别与传感器电感和电容之间的关系。利用该传感器对几种已知电导率溶液进行了测试,结果显示其测量的最大相对误差为0.64%,从而证明所提出的传感器测量方法不仅测量精度可行,还提高了测量的冗余度和可靠性,具有很高的商业应用价值。     

平行梁式电容传感器力学性能的仿真与分析

针对S型平行梁式电容称重传感器参数结构设计问题,运用有限元软件ANSYS Workbench对平行梁式弹性体结构进行参数化模拟仿真,基于二次多项式曲面拟合建立其结构力学性能与主要结构参数的函数关系,并通过算例分析验证了拟合公式的有效性。研究表明,拟合公式对复杂仿真计算后的结果有很好的近似,能更好的反应实际情况,公式结构更加简洁,具有较快的收敛速度、较高的精度和较好的推广能力,有利于准确实现平行梁式电容称重传感器结构参数设计。     

电网电压不平衡且严重畸变时的软件锁相技术

针对传统软件锁相环（SPLL）在三相电压不平衡且严重畸变条件下不能准确跟踪电网电压的频率和相位的问题。本文提出了一种基于相序解耦（SDR）级联二阶广义积分（SOGI）的新型软件锁相模型,通过SDR和SOGI实现了正负序分离,电压基波提取,以及滤波功能,有效地消除了负序分量、谐波分量对准确获取频率和相位信息的影响。仿真结果表明在三相电压不平衡且严重畸变的条件下,该新型SPLL能够准确地锁定电网电压的频率和相位,从而有效性地验证了新方法的正确性。     

腈纶NaSCN一步法生产中调整喷丝头负拉伸率的研究

采用硫氰酸钠为溶剂,湿纺一步法工艺生产腈纶,探讨了喷丝头负拉伸率对纤维成形的影响。工业化试验表明:当喷丝头负拉伸率为-73％时,纤维可纺性达到最佳状态。     

Electrochemical capacitance of well-coated single-walled carbon nanotube with polyaniline composites

Well-coated single-walled carbon nanotube (SWNT) with polyaniline (PANI) composite electrodes with good uniformity for electrochemical capacitors are prepared by the polymerization of aniline containing well-dissolved SWNTs. The capacitance properties are investigated with cyclic voltammetry, charge-discharge tests and ac impedance spectroscopy. The composite electrode shows much higher specific capacitance, better power characteristics and is more promising for application in capacitor than pure PANI electrode. The effect and role of SWNT in the composite electrode are also discussed in detail.     

A novel high power symmetric ZnO/carbon aerogel composite electrode for electrochemical supercapacitor

We present, for the first time, a new material of symmetric electrochemical supercapacitor in which zinc oxide (ZnO) with carbon aerogel (CA) was used as active material. Physical properties of ZnO/CA composite were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). It was found that ZnO has single hexagonal structure and the grain size increases with increase of ZnO compository. The result of cyclic voltammetry indicates that the specific capacitance of ZnO/CA composite in 6 M KOH electrolyte was approximately 25 F/g at 10 mV/s for 2:1 composition. AC impedance analysis reveals that ZnO with carbon aerogel powder enhanced the conductivity by reducing the internal resistance. Galvanostatic charge/discharge measurements were done at various current densities, namely 25, 50, 75, and 100 mA/cm². It was found that the cells have excellent electrochemical reversibility and capacitive characteristics in KOH electrolyte. The maximum capacitance of the ZnO/CA supercapacitor was 500 F/g at 100 mA/cm². It has been observed that the specific capacitance is constant up to 500 cycles at all current densities, which implies that the dendrite formation was controlled.     

耐高负压聚四氟乙烯衬里设备、管道制作工艺

聚四氟乙烯衬里设备、管道，经常会因为内部负压产生内瘪，以至拉裂损坏。本文讲述了一种特殊制造工艺：将聚四氟乙烯衬里外表面处理后，采用特殊粘接剂，将其与钢外壳粘接起来，以防止负压，延长产品使用寿命。     

不同泊松比复合材料的裂纹尖端应力场

具有平面负泊松比的碳纤维/环氧树脂非平衡复合材料层板具有很高的断裂韧性和缺口断裂强度。本文用复变函数一变分方法计算了负泊比材料的裂纹尖端应力场，并与常规的平衡复合材料进行了比较。本文重点研究了主应力方向与纤维夹角的关系。结果表明：负泊松比材料独特的裂纹尖端应力场有利于提高缺口断裂强度。     

对于水泥物理性能检测问题的研究

具体分析了水泥的细度、凝结时间、胶砂强度等物理性能的检测过程,以供参考。     

Matching ratio between positive and negative electrodes for double-layer capacitors

For double-layer capacitors in alkaline electrolyte, the specific capacitance of the positive electrode is not equal to that of the negative one. Thus, capacitor performance cannot be optimal with a positive/negative electrode matching ratio of 1. In this study nanoporous glassy carbons (NPGCs) were employed as the electrodes of capacitors, and the influence of matching ratio between positive and negative electrode on capacitor performance was systematically investigated. In aqueous KOH, the specific capacitance of the positive electrode is lower than that of the negative electrode. The matching ratio at which a maximum capacitance is obtained is dependent on the values of the positive and negative electrode capacitance. At low current rate, the highest specific capacitance is achieved at a matching ratio slightly higher than 1. At high current rate, a capacitor has the highest specific capacitance with the lowest resistance at a matching ratio of 1.5. This indicates that an optimum matching relationship between positive and negative electrodes is attained.