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本文首先分析电力电缆防火封堵的现状,对防火封堵系统基本情况进行介绍,并研究当前工程防火封堵的不足之处,以及对应的改善方法。之后,本文对电缆防火封堵验收指标进行探讨,并从电缆防火封堵验收要求出发,从工程角度出发,结合声发射和声成像技术,对开关柜电缆仓或电缆通道的防火封堵性能进行了测试和研究,给出了有效的评估和缺陷定位方法。在此过程中,本文对声发射技术与声学成像技术的基本内容进行分析,探讨工程检测应用重点,在电力电缆防火封堵中应用声发射技术与声学成像技术,测试结果显示通过应用该两项技术,能够根据幅值大小基本确定封堵缺陷情况。 相似文献
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石墨烯条带的电子结构与性质:电场及长度效应 总被引:1,自引:0,他引:1
在密度泛函理论(DFT)和含时密度泛函理论(TDDFT)的基础上对宽度上含有8个zigzag链的石墨烯条带(8-ZGNR)的基态和激发态的性质进行了理论研究,着重考察了条带长度及电场的影响.B3LYP杂化泛函的计算结果显示:在基态上,8-ZGNR的最低能量态并不具有磁性,随着长度的增加,才会显示出反铁磁的性质.静电场的加入使8-ZGNR显示出反铁磁性和半金属性.在激发态上,诱导电子会随着外激光脉冲的变化而发生移动和变化,但是相比而言,α自旋电子更容易被激发而产生较明显的诱导电子密度,而β自旋电子则更容易脱离外激光场的控制而产生非绝热现象. 相似文献
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The inelastic electron tunneling spectroscopy of edge-modified graphene nanoribbon-based molecular devices 下载免费PDF全文
The inelastic electron tunneling spectroscopy(IETS) of four edge-modified finite-size grapheme nanoribbon(GNR)-based molecular devices has been studied by using the density functional theory and Green's function method. The effects of atomic structures and connection types on inelastic transport properties of the junctions have been studied. The IETS is sensitive to the electrode connection types and modification types. Comparing with the pure hydrogen edge passivation systems, we conclude that the IETS for the lower energy region increases obviously when using donor–acceptor functional groups as the edge modification types of the central scattering area. When using donor–acceptor as the electrode connection groups, the intensity of IETS increases several orders of magnitude than that of the pure ones. The effects of temperature on the inelastic electron tunneling spectroscopy also have been discussed. The IETS curves show significant fine structures at lower temperatures. With the increasing of temperature, peak broadening covers many fine structures of the IETS curves.The changes of IETS in the low-frequency region are caused by the introduction of the donor–acceptor groups and the population distribution of thermal particles. The effect of Fermi distribution on the tunneling current is persistent. 相似文献
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本文简要介绍了激光表面处理技术在莱钢的应用情况及其效果,着重探讨了莱钢“激光加工处理中心”下一步的发展思路并提出一些具体措施。 相似文献
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