杆塔垂直接地装置冲击特性的频域分析方法

杆塔接地装置对输电线路的的安全稳定运行起着至关重要的作用,其冲击特性是考量杆塔防雷效果的重要参数。笔者基于矩量法和电路理论,以接地体的漏电流为未知量,建立接地网数值计算模型对杆塔接地装置的冲击特性进行频域分析。通过CDEGS软件计算结果进行对比,验证算法的有效性;着重计算杆塔垂直接地装置的冲击阻抗,分析垂直接地极长度对接地装置冲击特性的影响。     

Preparation and properties of heterocyclically conjugated poly(3‐hexylthiophene)–clay nanocomposite materials

A series of heterocyclically conjugated polymer–clay nanocomposite (PCN) materials that consisted of organic poly(3‐hexylthiophene) (P3HT) and inorganic montmorillonite (MMT) clay platelets were prepared by in situ oxidative polymerization with FeCl₃ as an oxidant. The as‐synthesized PCN materials were characterized by Fourier transform infrared (FTIR) spectroscopy, wide‐angle powder X‐ray diffraction (WAXRD), and transmission electron microscopy (TEM). The effects of the material composition on the anticorrosion, gas barrier, thermal stability, flammability, mechanical strength, and electrical conductivity properties of the P3HT and PCN materials were studied by electrochemical corrosion measurements, gas‐permeability analysis (GPA), thermogrametric analysis (TGA), limiting oxygen index (LOI) measurements, dynamic mechanical analysis (DMA), and a four‐point probe technique, respectively. The molecular weights of extracted and bulk P3HT were determined by gel permeation chromatography (GPC) with THF as an eluant. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3438–3446, 2004     

自并励励磁系统优化改造探讨

乐滩水电厂励磁系统设备运行近十年,设备出现老化,存在安全隐患,对1、2号机励磁系统的优化改造(包括硬件设计和软件设计),完善了控制逻辑,解决了励磁原回路设计缺陷、非专用直流灭磁开关、氧化锌电阻等系统故障率高多项重大安全隐患问题。完成改造后,进行了励磁系统静态试验、动态特性试验、PSS试验、进相试验等,试验技术指标结果均符合国标、部标、行标的要求,开、停机逻辑符合乐滩水电厂需求,联锁条件及判据满足安全要求,达到了改造的预期目的。1、2号机组励磁系统改造运行到今,设备稳定,励磁系统缺陷及故障率为零,效果良好。     

靶向壳聚糖基因载体与水溶性量子点的自组装

将透明质酸(HA)接枝到四种不同分子量的壳聚糖(CS)上,获得了靶向壳聚糖基因载体。将CS及接枝CS分别与水溶性量子点(QDs)自组装,研究发现,相对于纯QDs,CS/QDs复合物及接枝CS/QDs复合物的荧光强度均明显增强,荧光发射峰位发生红移。复合物呈核/壳结构,QDs被包裹在核内。和CS/QDs复合物相比,接枝CS/QDs复合物的尺寸更小,分布更为均一。     

Mechanistic investigation of hydrogen-enhanced anodic dissolution of X-70 pipe steel and its implication on near-neutral pH SCC of pipelines

The effects of hydrogen-charging on anodic dissolution of pipe steel under near-neutral pH condition were studied by electrochemical techniques. Hydrogen-charging enhances the anodic dissolution rate of the steel. The hydrogen-enhanced dissolution increases with increasing charging current density. The hydrogen effect is attributed to the alteration of chemical potential and exchange current density of steel. Hydrogen-charging affects the corrosion process of the steel. In particular, at a high charging current density, a layer of corrosion product forms on the electrode surface to change corrosion potential and interfacial double-charge layer capacitance as well as charge-transfer resistance. The hydrogen effect factor for enhanced anodic dissolution of steel at an anodic potential of −0.4 V (SCE) is 1.53 only. Hydrogen-enhanced anodic dissolution of steel by itself may not be the major factor contributing to the high rate of crack growth in pipe steel in near-neutral pH electrolyte. A further investigation of the synergistic effect of hydrogen and stress on dissolution at the crack-tip is essential to determine the mechanism of near-neutral pH stress corrosion cracking of pipelines.     

塑料抗菌剂国内外开发现状及市场分析

阐述了抗菌剂的种类及其作用机理,详细介绍了塑料抗菌剂的国内外市场、开发现状及发展趋势,对今后国内市场进行了预测,并提出了我国塑料抗菌剂的发展建议。     

新显色剂2，6－二溴－4－乙氧基偶氮胂直接吸光光度法测定微量铋

新显色剂２，６－二溴－４－乙氧基偶氮肿在１．５ｍｏｌ·Ｌ－１ＨＣｌＯ４介质中，与Ｂｉ（Ⅲ）生成稳定的深色络合物，最大吸收波长为６３９ｕｍ，摩尔吸光系数为９．６７×１０４Ｌ·ｍｏｌ－１·ｃｍ－１，灵敏度高，常见离子允许量大。Ｂｉ（Ⅲ）在０～２５μｇ／２５ｍＬ范围内符合比耳定律。以试样空白为参比，直接吸光光度法测定铜及铜合金中的铋，方法简便，结果令人满意。     

发展节能省地型住宅积极开发节能利废优质墙材产品

此文是作者于2005年6月25日在粉煤灰综合利用网和《粉煤灰综合利用》杂志社在上海共同召开的“第二届国际粉煤灰综合利用墙材革新和建筑节能高级论坛”上的发言,本刊略作删节发表。     

石英砂的塑性机理研究

研究了石英砂的塑性并对其进行改善,得出石英砂颗粒大小、砖坯含水率、砖坯p H值和增塑剂含量对砖坯塑性的影响规律及机理,并且为利用石英砂而采用可塑成型去制备高性能的烧结砖探索出了合适的成型工艺条件:球磨时间24h、含水率为29%、坯料p H=9和增塑剂含量为5%。     

Diagnosis of lossy resonator filters with source–Load coupling using Y‐parameters

This article presents a novel approach to extract the coupling matrix (CM) of a lossy cross‐coupled resonator bandpass filter with source–load coupling using admittance parameters (also known as Y‐parameters). The Y‐parameters are calculated by characteristic polynomials corresponding to the measured S‐parameters. The unloaded quality factor of resonators and the CM can be extracted from the Y‐parameters. The method allows one to diagnose a filter with source–load coupling without necessity of dealing with the degenerate poles problem of the Y‐parameters and the measurement noise. The proposed diagnosis method can be used in a filter tuning and speeds up its physical realization. The method is verified by a fabricated fourth‐order bandpass filter and a simulated substrate integrated waveguide dual‐mode filter with source–load couplings. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:713–717, 2014.