共查询到19条相似文献,搜索用时 93 毫秒
1.
2.
真空中陶瓷绝缘子的耐压能力严重受到其表面性能的制约,在远低于同尺寸的真空间隙的耐压强度和绝缘子体耐压水平的情况下,绝缘子就出现了击穿现象,即沿面闪络击穿。利用真空绝缘实验装置选用95氧化铝陶瓷和掺锰铬氧化铝陶瓷样品进行表面耐压试验,对不同组分的陶瓷样品的耐压性能比较,并探讨表面处理及测试法对绝缘子表面绝缘性能的影响。 相似文献
3.
EAST���ϲ��Ͼ�Ե����������Ԫ���� 总被引:3,自引:1,他引:3
用有限元法对EAST装置磁体系统的高性能氦气密复合材料绝缘子性能作了全面的分析.结果表明:绝缘子可满足承受EAST装置耐电压15kV的使用要求;热应力对绝缘子的绝缘层影响最大,外力对绝缘层应力的影响可忽略;EAST复合材料绝缘子具有优良的低温力学性能. 相似文献
4.
研究纳秒脉冲下的绝缘子沿面闪络影响因素对电磁脉冲模拟装置绝缘结构设计具有重要的借鉴意义。通过搭建绝缘子沿面闪络实验平台,实验研究了在0.5 MPa的SF6气体中,脉冲电压波形、绝缘材料和绝缘子沿面场强分布对绝缘子沿面闪络电压的影响。结果表明:绝缘子的闪络电压具有随着脉冲前沿时间减小而增加的趋势;相较于脉冲电压全波,绝缘子在脉冲电压前沿波形耐受下闪络电压较高;聚酰亚胺材料的绝缘性能最好;通过降低绝缘子沿面最大场强,改善电场分布可以有效地提高绝缘子的闪络电压。 相似文献
5.
绝缘子是电力系统中非常重要的一类电气设备,由于电、热、机械力、污秽的积累等环境因素的作用会使其绝缘性能出现劣化和下降,可能使得绝缘子的表面形成放电,甚至会发生沿面闪络,危害了电力系统的安全。在此基础上提出基于日盲紫外线精确测试紫外线强度的方法,研制了基于日盲紫外线检测技术的绝缘子电晕放电检测装置,通过不同劣化程度和不同污秽条件的盘行悬式瓷绝缘子的实际测试,验证了该装置通过日盲紫外线强度的监测能够定性判断绝缘子的劣化程度和污秽程度,为输电线路绝缘子实时状态监测提供依据。 相似文献
6.
7.
用有限元法对ITER装置磁体系统的高性能氦气密复合材料绝缘子的结构设计进行电场分析和力学性能分析。分析结果表明,绝缘子能够承受耐电压56kV、耐气压4MPa、耐拉力2000N、耐弯矩1000Nm、耐扭矩100Nm的技术参数要求;同时热应力分析结果表明,与外力作用的影响相比,热应力是影响绝缘子性能的关键因素;绝缘子在拉力、弯矩和扭矩受力下发生变形的是金属部分,外力对绝缘部分的影响不大。 相似文献
8.
用有限元法对ITER装置磁体系统的高性能氦气密复合材料绝缘子的结构设计进行电场分析和力学性能分析。分析结果表明,绝缘子能够承受耐电压56kV、耐气压4MPa、耐拉力2000N、耐弯矩1000Nm、耐扭矩100Nm的技术参数要求;同时热应力分析结果表明,与外力作用的影响相比,热应力是影响绝缘子性能的关键因素;绝缘子在拉力、弯矩和扭矩受力下发生变形的是金属部分,外力对绝缘部分的影响不大。 相似文献
9.
10.
目前,由于全球性淡水短缺,开发高效淡水制取技术迫在眉睫。热电空气制水因其小巧,性能可靠并且结构简单,而被应用于便携式野外生存制水。为进一步提升其制水能力,本文提出了一种新型回路热管辅助热电制水装置。基于传统热电制水装置,利用回路热管的高效换热性能对湿空气预冷,通过提升制冷量的方式提高其制水量。本文构建了新型装置的稳态仿真数学模型并与传统装置进行了对比分析。结果表明新型装置一天可以制取淡水2.12 L。与传统装置相比,新型装置的制冷量和制水量分别提高了16.22%和32.89%。此外,本文还研究了换热器热沉端的翅片数,进口湿空气的湿度以及质量流量对性能的影响。结果可为实际系统构建提供一定的理论指导。 相似文献
11.
Three-dimensional topological insulators are a new class of quantum matter which has interesting connections to nearly all main branches of condensed matter physics. In this article, we briefly review the advances in the field effect control of chemical potential in three-dimensional topological insulators. It is essential to the observation of many exotic quantum phenomena predicted to emerge from the topological insulators and their hybrid structures with other materials. We also describe various methods for probing the surface state transport. Some challenges in experimental study of electron transport in topological insulators will also be briefly discussed. 相似文献
12.
The recognition and localization of insulators is a crucial process of insulators’ failure detection. Aiming to identify insulators in test aerial image under the complicated background with no template and segmentation, a novel method of the recognition and localization of insulators based on SURF (Speeded Up Robust Features) and IFS (Intuitionistic Fuzzy Set) based on correlation coefficient is proposed as following: SURF is used to extract a set of feature points of the test aerial image. Then use IFS based on correlation coefficient to partition points into k classes. Find all the connected regions for each class, and calculate minimum circumscribed rectangle and shape characteristic value for each region to identify insulators, and localize them by rectangular boxes. Thus we can detect all the insulators from test aerial image correctly. Experimental results show that the proposed approach can obtain high precision in the recognition and localization of insulators. 相似文献
13.
ANSYS在低温压力容器应力分析与优化设计中的应用 总被引:7,自引:0,他引:7
介绍了大型有限元软件ANSYS在低温压力容器典型应力分析(不连续区局部应力分析、热应力分析、接触应力分析、复合材料应力分析)与优化设计中的应用,论证了ANSYS作为低温压力容器应力分析与优化设计有效手段的实用性和可靠性,为低温压力容器的应力分析和优化设计找到了一条新途径。 相似文献
14.
Experimental observation of pseudogap in a modulation-doped Mott insulator: Sn/Si(111)-(√30×√30)R30°
下载免费PDF全文
![点击此处可从《中国物理 B》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Yan-Ling Xiong 《中国物理 B》2022,31(6):67401-067401
Unusual quantum phenomena usually emerge upon doping Mott insulators. Using a molecular beam epitaxy system integrated with cryogenic scanning tunneling microscope, we investigate the electronic structure of a modulation-doped Mott insulator Sn/Si(111)-($\sqrt{3}\times \sqrt{3})R$30$^\circ$. In underdoped regions, we observe a universal pseudogap opening around the Fermi level, which changes little with the applied magnetic field and the occurrence of Sn vacancies. The pseudogap gets smeared out at elevated temperatures and alters in size with the spatial confinement of the Mott insulating phase. Our findings, along with the previously observed superconductivity at a higher doping level, are highly reminiscent of the electronic phase diagram in the doped copper oxide compounds. 相似文献
15.
Fu L 《Physical review letters》2011,106(10):106802
The recent discovery of topological insulators has revived interest in the band topology of insulators. In this Letter, we extend the topological classification of band structures to include certain crystal point group symmetry. We find a class of three-dimensional "topological crystalline insulators" which have metallic surface states with quadratic band degeneracy on high symmetry crystal surfaces. These topological crystalline insulators are the counterpart of topological insulators in materials without spin-orbit coupling. Their band structures are characterized by new topological invariants. We hope this work will enlarge the family of topological phases in band insulators and stimulate the search for them in real materials. 相似文献
16.
17.
18.
Rong Huang Donald H. Bilderback Kenneth Finkelstein 《Journal of synchrotron radiation》2014,21(2):366-375
Cornell energy‐recovery linac (ERL) beamlines will have higher power density and higher fractional coherence than those available at third‐generation sources; therefore the capability of a monochromator for ERL beamlines has to be studied. A cryogenic Si monochromator is considered in this paper because the perfect atomic structure of Si crystal is needed to deliver highly coherent radiation. Since neither the total heat load nor the power density alone can determine the severity of crystal deformation, a metric called modified linear power density is used to gauge the thermal deformation. For all ERL undulator beamlines, crystal thermal deformation profiles are simulated using the finite‐element analysis tool ANSYS, and wavefront propagations are simulated using Synchrotron Radiation Workshop. It is concluded that cryogenic Si monochromators will be suitable for ERL beamlines in general. 相似文献
19.
Martens HC 《Physical review letters》2006,96(7):076603
It is well known that even for minimal disorder one-dimensional wires are insulators: all 1D electron states are localized. Here, the influence of interwire coupling on delocalization of 1D states is examined. Based on perturbation theoretic arguments for the formation of 3D states in coupled wires and subsequent scaling analysis, practical expressions for the microscopic conditions of electronic delocalization and coherent conductivity of coupled 1D wires are obtained. The model quantitatively explains the temperature dependent dc conductivity in conducting polymers at both sides of the metal-insulator transition and links the experimental data to microscopic material parameters. 相似文献