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961.
介绍了目前国网电力系统的维护管理方法以及利用SCADA数据提高设备维护效率的方法。国网电力系统在SCADA数据的标准化建设方面投入了大量精力,使用SCADA数据进行分析,推动了电力标准化的需求。对电气开关设备、变压器寿命、运行中的设备和分接开关的运行进行了分析。分析了断路器和隔离开关在不同运行条件下的开关操作次数。据此得出,电气预防性维护应根据正常操作中的开关次数进行,对经常中断故障电流的断路器进行预防性维护。SCADA数据可用于设备的监测,从而为管理人员提供有价值的信息,并对电气设施的检修管理进行了分析。 相似文献
962.
为了分析石墨团聚的尺寸对焊接面粘合强度的影响,本文准备两种石墨团聚尺寸不同的AgWC(12)C(3)静银点,其中1号触点基材中石墨团聚尺寸约30-100μm,2号触点基材中石墨团聚约尺寸10-30μm,通过理化试验、钎焊高温验证以及界面微观扫描电镜等相关手段分析触点基材中石墨团聚的尺寸对基材与覆银层粘合强度的影响。最后得出结论,触点材料基材中的石墨分散度越低越不利于基材与覆银层有效的结合,从而使触点材料在焊接过程中由于界面结合力较弱导致覆银出现起泡现象,经过产品的电寿命和温升试验可以得出,在触点材料的基材中,分散度较好的石墨有利于焊接的钎着率,提高产品的电寿命。 相似文献
963.
964.
Silver‐coated copper nanowires (AgCuNWs) are prepared by chemical plating method with copper nanowires (CuNWs) and Ag‐amine reagent. The prepared AgCuNWs with silver content of 66.52 wt.%, diameter 28–33 nm exhibited improved anti‐oxidation behaviour. The silver coating on AgCuNWs can effectively reduce the formation of copper oxide under room temperature. The temperature at which nanowires begin to gain weight can be improved from 85 to 230°C and the maximum weight gain can be decreased from 20.3% to 3.2% by applying silver coating. The volume electrical resistivity of the AgCuNWs filled low‐density polyethylene nanocomposites is lower than that of the CuNWs filled low‐density polyethylene nanocomposites with same volume percentage of fillers because the silver content in the AgCuNWs is not oxidised during compression moulding. © 2012 Canadian Society for Chemical Engineering 相似文献
965.
Cocontinuous blends of 45/55 polypropylene (PP)/acrylonitrile‐butadiene‐styrene (ABS) with multiwall carbon nanotubes (MWNT) were prepared by melt‐mixing in a conical twin‐screw microcompounder. PP‐grafted‐maleic anhydride (PP‐g‐MA) and styrene MA were used as compatibilizers for PP/ABS blends. Scanning electron microscopic observations showed phase segregation of PP‐g‐MA in the blends. State of dispersion of MWNT in the presence or absence of the compatibilizers was assessed through AC electrical conductivity measurements and crystallization studies of the blends. An improvement in AC electrical conductivity was observed in blends in presence of either styrene MA or dual compatibilizers. The lowest electrical percolation threshold was achieved at 0.1 wt % of MWNT using sodium salt of 6‐amino hexanoic acid‐modified MWNT. Significant increase in crystallization temperature of PP phase of blends with MWNT was observed in the presence of compatibilizers as compared to blends without compatibilizers. An attempt has been made to address the complex issues of phase segregation, compatibilization, and dispersion of MWNT in cocontinuous blends of PP/ABS. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
966.
Velram Balaji Mohan Debes Bhattacharyya 《Polymer-Plastics Technology and Engineering》2020,59(7):780-796
ABSTRACTThe paper focuses on the investigation of the 3D printing of multi-functional composites using graphene nanoplatelets (GNP), polypyrrole (PPY) and linear low-density polyethylene (LLDPE). A holistic approach was performed and characterization methods to assess the properties of 3D printed composites and compared with those of compression molded composites and neat LLDPE to understand the factors affecting their performance. It has been noted that the 3D printed composites have superior mechanical and electrical properties than neat LLDPE, but slightly lower compared to those of compression molded composites having high packing density of fillers. The nominal increases were 13.2% (tensile strength), 31.9% (flexural strength), 29.4% (flexural modulus) and 24.7% (storage modulus). 相似文献
967.
为了解决传统高聚物减振复合材料的减振效果对温度的依赖性很大这个问题,根据压电导电原理研制了一种新型减振复合材料-压电导电型减振复合材料。本文概述了压电导电型减振复合材料的研究进展情况,归纳其优缺点,并预测其发展趋势和应用前景。 相似文献
968.
969.
970.
Masayuki Nagai Tatsuya Saeki Tadashi Nishino 《Journal of the American Ceramic Society》1990,73(5):1456-1460
Hydroxyapatite and Cl− -containing hydroxyapatite powders are prepared and characterized. Reversible substitution of CO2- 3 for OH− at the surface is presumed to be responsible for the sensor function. The role of Cl− , which is necessary to realize the sensor function and is incorporated during soaking treatment, is considered as follows. It may reduce the strain caused by the incorporation of CO2- 3 (which is larger than OH− ), and, hence, promote the reversible substitution reaction. This behavior is presumed because Cl− -containing hydroxyapatite samples exhibit sensor characteristics typical of CO2 without any treatment. 相似文献