模拟光耦SLC800在转台系统中的应用

在大功率转台控制系统中．存在着较大的电压干扰和电磁兼容问题。在转台的控制精度和驱动功率不断提高的情况下．本文使用模拟光耦隔离器件SLC800重新设计了转台中的某部分模拟电路．将功率放大电路和控制电路隔开，来增强系统的抗干扰能力和运行的可靠性。实验结果的分析和转台的运行表明：应用模拟光耦进行隔离，有效地消除了转台控制中的干扰和电磁兼容。     

基于Profibus-DP的西门子S7—300 PLC与ABB 800XA数据通信的实现

本文介绍基于Profibus—DP通信协议的西门子S7—300PLC与ABB 800XA系统之间的数据通信。详细描述了分别通过S7—300 PLC CPU的DP接口和CP342—5通信模块与ABB 800XA系统通信两种不同条件下的有关通信配置及实现数据通信的过程。     

高压直流偏磁对变压器的影响及抑制方法研究

宁东±660 kV直流输电工程在单极大地方式下会使接地极附近的变压器产生直流偏磁现象,直流偏磁是变压器的一种非正常工作状态,严重时可危及电网的安全运行.以串联电容法为技术基础的变压器中性点直流电流隔离接地装置的研制与开发,合理运用了氧化锌阀组和大容量快速开关作为电容器的双重保护,可以有效地阻断变压器中性点直流电流的流入,避免变压器直流偏磁显现的发生,保证了电网安全稳定运行.     

Incoloy 800H/20g复合板材料焊接技术探讨

研究Incoloy 800H／20g复合板焊接工艺，以解决以镍基合金复合板材为主体的设备在焊接过程中易产生裂纹、气孔及成分偏析等问题。焊接实验选择H1Cr16Ni21作为过渡填充金属，采用惰性气体保护焊和手丁电弧焊2种形式焊接。实验结果表明，选择H1Cr16Ni21作为过渡填充金属，采用小电流、多道次焊接工艺，可得到质量良好的焊缝，焊缝宽度、焊缝余高、咬边及焊接错边均符合JB4730-94标准要求；力学性能优于20g耐热钢。焊缝成分与Incoloy800H接近。成功地解决了成分差异较大的2种材料焊接时易出现裂纹和气孔的问题。     

国产800级碳纤维表面状态及其复合材料界面性能EI北大核心CSCD

通过扫描电子显微镜（SEM）、原子力显微镜（AFM）、X射线光电子能谱（XPS）、复丝拉伸法、单丝拉伸法及单丝断裂法对3种国产800-12K碳纤维表面状态及其复丝拉伸性能、单丝复合体系的界面性能进行系统分析与研究。结果表明：3种国产800级碳纤维表面均较为光滑,纤维的粗糙度为9-17nm,纤维表面含氧量较高且稳定,O/C在0.23~0.27之间;3种国产800级碳纤维复丝拉伸强度相当,质量控制稳定,断裂伸长率为1.9左右,纤维与树脂基体匹配性较好;3种国产800级碳纤维单丝拉伸强度不稳定,纤维的表面化学活性对纤维与树脂基体的界面结合强度影响显著。     

Carburization performance of Incoloy 800HT in CH4/H2 gas mixtures

Carburization performance of Incoloy 800HT has been studied after cyclic and isothermal exposures to CH₄/H₂ carburizing gas mixtures at high temperatures for 500 h. At 800 °C in 2% CH₄/H₂, Incoloy 800HT suffered external oxidation and carburization, the external continuous layer of reaction products consists primarily of Cr₇C₃, Mn_1.5Cr_1.5O₄, and FeCr₂O₄ with Fe(Cr, Al)₂O₄ as a minor phase. At 1100 °C in 10% CH₄/H₂, external carburization did not occur likely due to high carbon dissolution in the alloy substrate at this temperature. A thermodynamic analysis indicated that 1000 °C was an approximate critical temperature, below which the environment should result in mixed oxidizing/carburizing behavior, while above this temperature reducing carburizing behavior should occur. The experimental results approximately agree with the thermodynamic analysis. Metal dusting was not observed under highly carburizing conditions (a_C>1). The size and morphology of Cr-rich phases (or Cr-carbides) are both temperature- and time-dependent, while the external continuity is more temperature-dependent rather than time-dependent.     

±1100kV吉泉线雷击致灾因子权重分析及高风险杆塔筛选

目前已知输电线路雷击致灾因子主要包括雷电参数、地形地貌、绝缘配置、接地电阻等,但针对某条特定的线路,无法获得各因子对雷击风险的权重占比.以±1100 kV吉泉线为研究对象,深入挖掘该线路的雷击致灾因子,利用雷电灾害风险评估层次分析法,通过计算隶属度、构建判断矩阵对各致灾因子的权重占比进行分析.研究结果表明,该线路的沿线...     

海水环境下老化周期对T800碳纤维/环氧树脂复合材料的影响EI北大核心CSCD

研究T800碳纤维/环氧树脂基复合材料在海水环境中进行湿热腐蚀老化,将制备好的试件放置在人工制备70℃,3.5%NaCl溶液中腐蚀30,60,90 d,通过质量变化、老化前后表面形貌、红外光谱、动态力学性能、压缩实验和层间剪切实验分析材料的力学性能变化。结果表明:T800碳纤维/环氧树脂复合材料在3.5%NaCl溶液中吸湿率分别为0.39%,0.47%,0.53%;未老化试样纤维与基体之间黏结良好,在3.5%NaCl溶液老化后纤维与基体界面破坏随时间的增加老化更加严重;玻璃化转变温度T_(g)下降,分别在老化30,60,90 d后从189.16℃下降到177.54,171.88,168.06℃;经3.5%NaCl溶液老化后,老化30,60,90 d试样的最大破坏载荷分别降低3.2%,8.4%,15.3%,压缩强度分别降低3.0%,8.2%,15.9%;层间剪切最大破坏载荷分别降低3.0%,9.2%,14.9%,剪切强度分别降低3.0%,9.7%,16.4%。     

Experimental Investigation of the A-TIG Welding Process of Incoloy 800H

This work attempts to investigate the influence of different flux powders in the activated-TIG welding process of the Incoloy 800H super alloy. Three different fluxes (SiO₂, ZnO, and 50% ZnO +50% SiO₂) were used and welded under the same conditions and process parameters. The oxide fluxes used were in the form of nanoparticle powders. The metallurgical characteristics and mechanical properties were analyzed, and it was found that the SiO₂ flux could increase the depth of penetration whereas a ZnO flux was detrimental to this effect. Although a SiO₂ flux increased the depth of penetration, it led to a sensitization issue in the grain boundary. The combination of the fluxes 50% ZnO +50% SiO₂ produced a moderate increase in the depth of penetration compared to ZnO flux-coated weldments, but revealed a dendritic structure in the weld region.     

DSJ800可伸缩带式输送机技术改造

根据淄矿集团许厂煤矿和岱庄煤矿的生产准备要求,对DSJ800可伸缩带式输送机的机头部、驱动部、游动小车和机尾等进行技术改造。