对200 k V交联聚乙烯直流电缆进行了预鉴定试验,采用气相色谱-质谱法(GC-MS)和差示扫描量热法(DSC)分析了预鉴定试验前后交联聚乙烯主绝缘层内侧材料的理化特性,并在30~90℃下对主绝缘层内侧切片试样的极化电流以及去极化电流进行检测,...对200 k V交联聚乙烯直流电缆进行了预鉴定试验,采用气相色谱-质谱法(GC-MS)和差示扫描量热法(DSC)分析了预鉴定试验前后交联聚乙烯主绝缘层内侧材料的理化特性,并在30~90℃下对主绝缘层内侧切片试样的极化电流以及去极化电流进行检测,分析了预鉴定试验对交联聚乙烯电导特性的影响。结果表明:交联聚乙烯电缆绝缘层内侧材料中的主要交联副产物为甲基苯乙烯、苯乙酮和苯甲醇,经预鉴定试验中的冷、热循环老化后,3种主要交联副产物含量均明显下降,表明预鉴定试验可促进交联聚乙烯电缆绝缘层内侧交联副产物的脱离,从而使得电缆绝缘层内侧交联副产物含量下降;交联聚乙烯的电导特性与交联副产物含量密切相关,预鉴定试验后主要交联副产物的含量下降,减少了由副产物等杂质高电场解离形成的离子含量,从而有效降低了交联聚乙烯的电导率;电缆交联聚乙烯绝缘的结晶度在预鉴定试验后略有上升,对应的陷阱深度变浅,松弛过程变快;对去极化电流曲线使用三阶指数模型进行拟合,发现经预鉴定试验电缆的松弛时间常数均小于未试验电缆。受无定形区与晶区的界面极化以及交联副产物影响的松弛过程所对应的时间常数随着温度的上升呈先增大后减小的趋势。展开更多
Naval ship deperming is effective to reduce the potential damage from sea mines some of which sense magnetic field of the ship, and thus, is an important treatment of naval ships in the recent world. Large electric cu...Naval ship deperming is effective to reduce the potential damage from sea mines some of which sense magnetic field of the ship, and thus, is an important treatment of naval ships in the recent world. Large electric current is required to impose the magnetic field on the ship hull, which in turn means that the deperming coil needs to be wound on ship hull when the coil is composed of conventional conductive materials, such as copper. We considered a few HTS （high temperature superconducting） coil systems to deperm naval ships because we expect the shorter deperming time and lower manual workload for ship deperming operation, compared conventional conductor coil systems. We have in the past presented a solution using a fiat two-coil system arranged on seabed with tightly bound HTS conductor by analytical calculation of magnetic field on the conductor. By considering present and already developed technologies, a conductor with cylindrically wound on the core arranged as fiat multi-turn coils on seabed was designed using analytical methods.展开更多
Carbon films prepared from pyrolyzation of spin-casted polyacrylonitrile （PAN） thin films display high electrical conductivity （〉600 S/cm, at 1000 ℃ carbonization）, low sheet resistance （about 100 Y2/square at ...Carbon films prepared from pyrolyzation of spin-casted polyacrylonitrile （PAN） thin films display high electrical conductivity （〉600 S/cm, at 1000 ℃ carbonization）, low sheet resistance （about 100 Y2/square at the PAN film thickness of 70 nm） and partial transmittance. These pyrolyzed PAN （PPAN） films were patterned as bottom electrodes by photolithography, and utilized as drain and source electrodes to fabricate organic field-effect transistor （OFET） devices with a p-type semiconductor （P3HT） and an n-type semiconductor （DPP-containing quinoidal small molecule） through a spin-coating procedure. The results showed that the devices with the PAN electrodes exhibited almost the same excellent performance without any further modification compared to those devices with traditional Au electrodes. Since these PPAN films had the advantages of low-cost, high performance, easier for large-area fabrication, thermal and chemical stability, it should be a promising electrode material for organic electrodes.展开更多
This paper is concerned with the decay estimate of high-order energy for a class of special time-dependent structural damped systems represented by Fourier multipliers. This model is widely used in the fields of semic...This paper is concerned with the decay estimate of high-order energy for a class of special time-dependent structural damped systems represented by Fourier multipliers. This model is widely used in the fields of semiconductivity, superconductivity, electromagnetic waves, electrolyte and electrode materials, etc.展开更多
PbTiO_(3)-BiScO_(3) ceramics possess high piezoelectricity and high Curie temperature simultaneously,presenting a very promising candidate for high-temperature actuators and transducers.Figuring out the underlying pie...PbTiO_(3)-BiScO_(3) ceramics possess high piezoelectricity and high Curie temperature simultaneously,presenting a very promising candidate for high-temperature actuators and transducers.Figuring out the underlying piezoelectric mechanisms is of great importance for its application.Herein,we reveal the quantified intrinsic and extrinsic contributions to the high electrostrain of the morphotropic composition with phase coexistence by employing the advanced in situ electrical biasing high-energy synchrotron X-ray diffraction combined with the STRAP(strain,texture,and Rietveld analysis for piezoceramics from diffraction)methodology.An electric field-induced phase transformation is observed between the coexisting tetragonal and rhombohedral phases.It is found that the tetragonal phase contributes most of the domain switching strain,while the predominant lattice strain is from the rhombohedral phase.With phase fraction changes,the quantitative results demonstrate that the fieldinduced electrostrain is mainly contributed by the intrinsic lattice strain.In contrast,the high irreversible domain switching strain dominates the large remanent strain.It implies that transforming the large remanent strain into reversible strain would be a strategic direction to improve the piezoelectric response.The present results provide a further understanding of the high piezoelectricity and could help to advance the application of PbTiO_(3)-BiScO_(3).展开更多
文摘对200 k V交联聚乙烯直流电缆进行了预鉴定试验,采用气相色谱-质谱法(GC-MS)和差示扫描量热法(DSC)分析了预鉴定试验前后交联聚乙烯主绝缘层内侧材料的理化特性,并在30~90℃下对主绝缘层内侧切片试样的极化电流以及去极化电流进行检测,分析了预鉴定试验对交联聚乙烯电导特性的影响。结果表明:交联聚乙烯电缆绝缘层内侧材料中的主要交联副产物为甲基苯乙烯、苯乙酮和苯甲醇,经预鉴定试验中的冷、热循环老化后,3种主要交联副产物含量均明显下降,表明预鉴定试验可促进交联聚乙烯电缆绝缘层内侧交联副产物的脱离,从而使得电缆绝缘层内侧交联副产物含量下降;交联聚乙烯的电导特性与交联副产物含量密切相关,预鉴定试验后主要交联副产物的含量下降,减少了由副产物等杂质高电场解离形成的离子含量,从而有效降低了交联聚乙烯的电导率;电缆交联聚乙烯绝缘的结晶度在预鉴定试验后略有上升,对应的陷阱深度变浅,松弛过程变快;对去极化电流曲线使用三阶指数模型进行拟合,发现经预鉴定试验电缆的松弛时间常数均小于未试验电缆。受无定形区与晶区的界面极化以及交联副产物影响的松弛过程所对应的时间常数随着温度的上升呈先增大后减小的趋势。
文摘Naval ship deperming is effective to reduce the potential damage from sea mines some of which sense magnetic field of the ship, and thus, is an important treatment of naval ships in the recent world. Large electric current is required to impose the magnetic field on the ship hull, which in turn means that the deperming coil needs to be wound on ship hull when the coil is composed of conventional conductive materials, such as copper. We considered a few HTS （high temperature superconducting） coil systems to deperm naval ships because we expect the shorter deperming time and lower manual workload for ship deperming operation, compared conventional conductor coil systems. We have in the past presented a solution using a fiat two-coil system arranged on seabed with tightly bound HTS conductor by analytical calculation of magnetic field on the conductor. By considering present and already developed technologies, a conductor with cylindrically wound on the core arranged as fiat multi-turn coils on seabed was designed using analytical methods.
基金supported by the Chinese Ministryof Science and Technology (2013CB632506, 2011CB932304)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB12000000)the National Natural Science Foundation of China(21290191, 21333011)
文摘Carbon films prepared from pyrolyzation of spin-casted polyacrylonitrile （PAN） thin films display high electrical conductivity （〉600 S/cm, at 1000 ℃ carbonization）, low sheet resistance （about 100 Y2/square at the PAN film thickness of 70 nm） and partial transmittance. These pyrolyzed PAN （PPAN） films were patterned as bottom electrodes by photolithography, and utilized as drain and source electrodes to fabricate organic field-effect transistor （OFET） devices with a p-type semiconductor （P3HT） and an n-type semiconductor （DPP-containing quinoidal small molecule） through a spin-coating procedure. The results showed that the devices with the PAN electrodes exhibited almost the same excellent performance without any further modification compared to those devices with traditional Au electrodes. Since these PPAN films had the advantages of low-cost, high performance, easier for large-area fabrication, thermal and chemical stability, it should be a promising electrode material for organic electrodes.
基金supported by the National Natural Science Foundation of China (No.10871175)
文摘This paper is concerned with the decay estimate of high-order energy for a class of special time-dependent structural damped systems represented by Fourier multipliers. This model is widely used in the fields of semiconductivity, superconductivity, electromagnetic waves, electrolyte and electrode materials, etc.
基金supported by the National Natural Science Foundation of China(21825102,22075014 and 12004032)the Fundamental Research Funds for the Central Universities,China(06500162)+2 种基金the National Postdoctoral Program for Innovative Talents(BX20200044)German Research Society(DFG)(HI 1867/1-2)supported by the U.S.Department of Energy,Office of Science,Office of Basic Energy Sciences,under Contract No.DE-AC02-06CH11357.
文摘PbTiO_(3)-BiScO_(3) ceramics possess high piezoelectricity and high Curie temperature simultaneously,presenting a very promising candidate for high-temperature actuators and transducers.Figuring out the underlying piezoelectric mechanisms is of great importance for its application.Herein,we reveal the quantified intrinsic and extrinsic contributions to the high electrostrain of the morphotropic composition with phase coexistence by employing the advanced in situ electrical biasing high-energy synchrotron X-ray diffraction combined with the STRAP(strain,texture,and Rietveld analysis for piezoceramics from diffraction)methodology.An electric field-induced phase transformation is observed between the coexisting tetragonal and rhombohedral phases.It is found that the tetragonal phase contributes most of the domain switching strain,while the predominant lattice strain is from the rhombohedral phase.With phase fraction changes,the quantitative results demonstrate that the fieldinduced electrostrain is mainly contributed by the intrinsic lattice strain.In contrast,the high irreversible domain switching strain dominates the large remanent strain.It implies that transforming the large remanent strain into reversible strain would be a strategic direction to improve the piezoelectric response.The present results provide a further understanding of the high piezoelectricity and could help to advance the application of PbTiO_(3)-BiScO_(3).
