固态去耦合器在解决阀室阴保漏电问题中的应用

干线埋地管道均为强制电流+外防腐层联合保护方式,这就要求被保护管道有良好的绝缘性能。阀室内管道与电气之间采用绝缘卡套进行绝缘,放空管与阀室内管道间也存在绝缘接头。基于电气安全考虑,阀室电气设备均有接地,如果管道与接地网搭接或绝缘失效,将会造成阀室管道电位偏正,阴保处于欠保护状态。因此针对运行的阀室,做好绝缘排查,消除阴保电流流失,确保阀室埋地管道处于良好的阴极保护状态尤为重要。本文通过对某输油线某阀室阴保漏电进行原因排查并采用了固态去耦合器解决了阀室阴极保护漏电,对解决阀室阴极保护漏电提供了一种全新的思路和方法。     

漏电导致阴极保护绝缘接头内腐蚀失效的有限元分析

对漏电导致阴极保护绝缘接头内腐蚀失效问题,建立了绝缘接头有限元计算模型,开展了绝缘接头漏电电流密度大小与分布数值计算,并讨论了管道绝缘接头两侧电位差,输送介质电阻率和绝缘接头内涂层缺陷对绝缘接头漏电电流密度大小与分布的影响规律.模拟计算结果与油田现场失效绝缘接头内腐蚀现象一致,并给出了相应的防护建议.     

埋地钢管阴极保护检测中的问题与对策

文章提出了阴极保护检测中电火花检漏盲区、漏点定性定量、阴极保护基准电位、IR降、深水层检测、牺牲阳极、管道交叉搭接漏电检测及检测速度与效益,检测项目与设备技术等问题,提出了解决上述问题的对策。     

浅析东临复线输油管道阴极保护距离缩短的原因

通过多种测试方法对东临复线输油管道阴极保护系统的检测,发现防腐层老化、漏电点多是该管线阴极保护距离缩短的主要原因.为此,提出了处理方法和预防措施,建议对管道腐蚀与防护系统的技术现状和管道整体安全性进行科学评价.     

嵌入电子防腐功能的太阳能控制系统设计

本文主要介绍了一款低成本、高稳定性的太阳能控制系统设计方案,该控制系统具有电子防腐保护、漏电检测保护、水温水位显示、自动上水、辅助电加热、管道防冻功能等。     

在役管道绝缘法兰绝缘性能检测与预防

为防止绝缘法兰绝缘性能变差,影响长输管道阴极保护系统的运行,有必要对绝缘法兰的绝缘性能进行检测。结合A站、B站及C站三座场站,利用通断电位法、漏电率检测等方法对在役长输管道绝缘法兰绝缘性能进行评价及分析,虽然绝缘法兰内侧电位因外侧电位的变化而有微弱的波动,通过测试A站、B站及C站的绝缘法兰漏电率,漏电率均在15%以下,分析内侧电位的波动主要是由于绝缘法兰外侧在通断过程中地电场的变化而引起的微弱变化,与绝缘法兰失效无关。A站、B站及C站三座场站绝缘法兰绝缘性能良好,同时提出了预防绝缘法兰失效的对策。     

漏电保护系统中计算机管理中心监控软件的设计

本文详细介绍了漏电保护系统中计算机管理中心监控软件的设计实现方法,该软件可以通过电话网或RS485接口环境完成与下位智能漏电保护装置的数据通信,并进一步通过通信转换器对管理漏电信息监测网络中的智能漏电保护装置进行管理,最终实现对农村或城市居民小区配电线路漏电流变化状况的远程监测和控制。     

谈谈高层建筑漏电火灾报警系统的设计

阐述了《高层民用建筑设计防火规范》中“漏电火灾报警系统”的组成及目前常用的漏电火灾报警产品的分类，并以施耐德公司的网络方案为例，详细介绍了高层建筑漏电火灾报警系统中的关键元件及其系统应用情况。     

铝电解槽漏电现象探讨

铝电解槽漏电会形成电流空耗，导致电流效率降低，还危及到人身安全。本文对漏电的形式及漏电原因结合实例加以分析，提出了解决漏电的一些措施。     

SB70变频器漏电流的抑制方法

漏电流包括对地漏电流和线间漏电流。为降低载波频率,所使用的电动机电缆要尽可能地短。介绍了在变频器系统和其它系统中,使用针对高谐波和浪涌漏电流而设计的漏电断路器,使用温度传感器直接监测电动机温度或使用变频器本身的电动机过载保护功能代替外部热继电器,在输出侧安装电抗器等变频器漏电流的抑制方法。     

脉冲电流对Zn-42%Al合金定向凝固行为的影响

采用Zn-42%Al合金作为试验材料,研究不同电流强度和脉冲频率下脉冲电流对合金定向凝固组织的影响.结果表明,随着脉冲电流强度的增大,组织得到更加明显的细化;脉冲电流细化组织的作用对脉冲频率存在一个极限响应,当脉冲振荡频率过高,脉冲电流的细化组织效果会被削弱.     

On Peculiarities of Welding and Destruction of the Surface of High-Current Layered Contacts by Pulsed Currents

Numerical modeling of the impact of short-duration pulsed currents on closed high-current copper- coated aluminum contacts is carried out. The modes of the current effects are studied which induce a significant contact area heating and cause melting and welding of the contacts. The influence of the copper coating thickness on the dynamics of the heating of the contacts is determined. In the course of the experimental study of the action of the shock short-circuit currents on the layered contacts, a comparative analysis was carried out of the resistance of the copper coating to such actions. The latter was manufactured using the sputtering and plating techniques. The heating levels of the contact surface, which cause its destruction during the breakup of the occurring thermal bonds, are determined. The destruction of the sputtered coating is observed to occur as soon as the stage of the diffusion welding begins, whereas the plated layers are not significantly damaged at the same current levels.     

甲状腺激素的非基因作用与心血管功能

甲状腺激素能通过基因作用及非基因作用对机体几乎所有组织产生生理调节作用,通常认为甲状腺激素发挥其生理作用是由核受体调节基因转录介导的,但越来越多的证据表明甲状腺激素亦可与细胞膜、胞浆或线粒体内受体结合触发非基因信号作用,快速调节心血管功能。长期以来甲状腺激素的非基因作用对心血管功能的影响极少有人涉及,本文综述甲状腺激素通过非核受体、第二信使及效应蛋白介导的非基因作用对心血管系统的影响,旨在为心血管疾病的有效治疗和药物开发提供新的途径或靶点。     

硝普钠对离体视上核神经元的抑制和兴奋作用1

目的 观察NO 供体硝普钠(SNP) 对视上核(SON) 神经元的影响, 以了解NO 对SON 细胞活动的调节作用。方法 对成年大鼠下丘脑切片SON神经元进行细胞内生物电记录, 测定细胞电生理参数。结果 在11 个安静的细胞灌流给药SNP(1 m mol·L^-1) 3 ~ 5 min, 使55 %的细胞发生去极化(P <0.05), 伴有膜电阻和时间常数减小, 而使45 %的细胞超极化(P <0.05) 。SNP 使73 %细胞的诱发动作电位的幅度和超射值减小、半幅时程增大(P <0.05), 并伴放电频率降低、电流_电压曲线斜率减小、AHP幅度增大(P <0.05);但在6 个有自发性放电的细胞, SNP使67 %细胞的自发性放电频率升高(P <0.05)。结论 SNP 能细胞类型和功能状态依赖性地对SON 神经元产生兴奋性或抑制性影响, 提示NO 对SON 细胞活动有不同的调节作用。     

The role of selective attention and action selection in the development of multiple action capabilities

In this paper we illustrate how the capacity to select the most appropriate actions when handling contexts affording multiple conflicting actions can be solved either through a selective attention strategy (in which the stimuli affording alternative actions are filtered out at the perceptual level through top-down regulation) or at later processing stages through an action selection strategy (through the suppression of the premotor information eliciting alternative actions). By carrying out a series of experiments in which a neuro-robot develops an ability to choose between conflicting actions, we were able to identify the conditions that lead to the development of solutions based on one strategy or another. Overall, the results indicate that the selective attention strategy constitutes the most simple and straightforward mechanism enabling the acquisition of such capacities. Moreover, the characteristics of the adaptive/learning process influence whether the adaptive robot converges towards a selective attention and/or action selection strategy.     

FeCrBSiNb粉芯丝材电弧喷涂的弧区动态行为

电弧喷涂粉芯丝材是由金属外皮包覆金属或非金属的复合粉末组成,喷涂过程中在弧区发生冶金反应并雾化成熔滴,大量熔滴沉积在基体表面最终形成涂层。粉芯丝材的电弧喷涂是一个高度动态的传热传质过程,采用高速摄像技术研究了喷涂过程中两根粉芯丝材交汇处的电弧、丝材熔化与熔滴形成等行为。另外,通过高速摄像试验分析了喷涂电流和电压对电弧形态及丝材熔化的影响规律。结果表明:喷涂时间歇出现燃弧、熄弧、再燃弧的循环变化;不同于实心丝材,粉芯丝材在阴阳极上的电弧都发散,这有利于丝材外皮和粉芯间的冶金反应;阴极丝材主要表现为抽吸作用下以细小熔滴或片状挤出物等形式形成熔滴,阳极丝材主要以片状液带的形式脱离并雾化成小熔滴。     

洛芬待因镇痛作用的组方分析

目的 观察洛芬待因(可待因+布洛芬)的镇痛作用及其组方分析。方法 采用小鼠扭体法、热板法、二甲苯所致小鼠耳廓肿胀法等毒理和药效试验,观察洛芬待因及其各组分的镇痛作用,用金氏法分析药物相互作用性质。结果 可待因和布洛芬按13∶200 配方其镇痛作用增强,同时也能增加布洛芬的抗炎作用,毒性下降。结论 洛芬待因的组方是合理的。     

中国加入WTO对钢管行业的影响

对中国加入WTO后钢管行业存在的有利因素和不利因素进行了分析,此外还分析了我国石油管及电站用高压锅炉管的生产现状,与国外产品的差距以及面临的挑战。指出了宝钢钢管分公司要盈利,在营销方面应采取缩短销售渠道,发展配送服务,推行电子商务等措施。     

The hydrogen permeation investigation of API X56 steel in sea mud

It was found that the corrosion rate of steel in the sea mud with sulfate‐reducing bacteria (SRB) could be as high as 10 times of that in the sea mud without SRB. And the hydrogen permeation reaction would occur when metals were corroded. So it is necessary to investigate the effect of living SRB on hydrogen permeation in the sea mud. Cathodic potential was often added to metals in order to protect them. But hydrogen permeation could be affected by the cathodic potential. So it is also necessary to study the effect of cathodic potential on hydrogen permeation. In this paper, the hydrogen permeation actions of API X56 steel in the sea mud with and without SRB at corrosion and cathodic potential were studied with an improved Devanathan‐Stachurski's electrolytic cell. Experimental results showed that during the growth of SRB, the current density curve of hydrogen permeation was accordant with the growth curve of SRB. But the hydrogen permeation current density of API X56 steel hardly changed in the sterilized sea mud. Compared with the hydrogen permeation current density of API X56 steel in the sterilized sea mud, the hydrogen permeation of API X56 steel in the sea mud could be accelerated by living SRB. Experimental results also showed that the hydrogen permeation current density increased rapidly when the cathodic potential was added to the three‐electrode system of the cathodic cell, and then the hydrogen permeation current density could obtain a stable value slowly. So the cathodic potential added to the cathodic cell could accelerate hydrogen permeation.     

埋地钢管腐蚀隐患检测及整改方案的制订

埋地管道腐蚀隐患整改措施应根据具体情况，进行经济技术比较后确定。本文结合深圳市燃气集团的实际工程，介绍了整改前应检测的内容和方法，及整改时应考虑的因素，对科学地制定整改方案具有借鉴意义。