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Effect of neutral polymeric bonding agent on tensile mechanical properties and damage evolution of NEPE propellant
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作者 M.Wubuliaisan Yanqing Wu +3 位作者 Xiao Hou Kun Yang Hongzheng Duan Xinmei Yin 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第2期357-367,共11页
Introducing Neutral Polymeric bonding agents(NPBA) into the Nitrate Ester Plasticized Polyether(NEPE)propellant could improve the adhesion between filler/matrix interface, thereby contributing to the development of ne... Introducing Neutral Polymeric bonding agents(NPBA) into the Nitrate Ester Plasticized Polyether(NEPE)propellant could improve the adhesion between filler/matrix interface, thereby contributing to the development of new generations of the NEPE propellant with better mechanical properties. Therefore,understanding the effects of NPBA on the deformation and damage evolution of the NEPE propellant is fundamental to material design and applications. This paper studies the uniaxial tensile and stress relaxation responses of the NEPE propellant with different amounts of NPBA. The damage evolution in terms of interface debonding is further investigated using a cohesive-zone model(CZM). Experimental results show that the initial modulus and strength of the NEPE propellant increase with the increasing amount of NPBA while the elongation decreases. Meanwhile, the relaxation rate slows down and a higher long-term equilibrium modulus is reached. Experimental and numerical analyses indicate that interface debonding and crack propagation along filler-matrix interface are the dominant damage mechanism for the samples with a low amount of NPBA, while damage localization and crack advancement through the matrix are predominant for the ones with a high amount of NPBA. Finally, crosslinking density tests and simulation results also show that the effect of the bonding agent is interfacial rather than due to the overall crosslinking density change of the binder. 展开更多
关键词 Solid propellant Bonding agent Mechanical properties Damage evolution Cohesive-zone model interface debonding
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Numerical Simulation of Particle/Matrix Interface Failure in Composite Propellant 被引量:6
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作者 常武军 鞠玉涛 +2 位作者 韩波 胡少青 王政时 《Defence Technology(防务技术)》 SCIE EI CAS 2012年第3期146-153,共8页
Interface debonding between particle and matrix in composite propellant influences its macroscopic mechanical properties greatly. For this, the laws of interface cohesive damage and failure were analyzed. Then, its mi... Interface debonding between particle and matrix in composite propellant influences its macroscopic mechanical properties greatly. For this, the laws of interface cohesive damage and failure were analyzed. Then, its microscopic computational model was established. The interface mechanical response was modeled by the bilinear cohesive zone model. The effects of interface properties and particle sizes on the macroscopic mechanical behavior were investigated. Numerical simulation of debonding damage evolution of composite propellant under finite deformation was carried out. The debonding damage nucleation, propagation mechanism and non-uniform distribution of microscopic stress-strain fields were discussed. The results show that the finite element simulation method based on microstructure model can effectively predict the trend of macroscopic mechanical behavior and particle/matrix debonding evolution process. It can be used for damage simulation and failure assessment of composite propellants. 展开更多
关键词 propulsion system of aviation and aerospace interface debonding cohesive zone model composite propellant cohesive element damage evolution
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Interface dipole induced by asymmetric exchange effect in Mott-insulator/Mott-insulator heterojunction
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作者 郝雷 汪军 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第11期4305-4311,共7页
We study theoretically the interracial electronic property of a heterojunction made from two Mott insulators (MI) with different magnetic structures. By means of unrestricted Hartree-Fock calculations in real space,... We study theoretically the interracial electronic property of a heterojunction made from two Mott insulators (MI) with different magnetic structures. By means of unrestricted Hartree-Fock calculations in real space, we find that a charge dipole can form spontaneously near the interface of the MI/MI heterojunction. The magnitude of this charge dipole depends strongly on the magnetic states of both sides of the heterojunction. Combining with the result from an exactly solvable two-site toy model, we argue that the interface dipole arises from exchange effects as well as its asymmetry intrinsic to the heterojunction near the interface. Our study may shed light on the fabrication of ultrathin ferroelectric and magnetoelectric devices. 展开更多
关键词 Mott insulator heterojunction interface dipole asymmetric exchange
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Magnetic Proximity Effect in an Antiferromagnetic Insulator/Topological Insulator Heterostructure with Sharp Interface
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作者 刘宇新 牛雪翻 +3 位作者 张仁聪 张庆华 滕静 李永庆 《Chinese Physics Letters》 SCIE CAS CSCD 2021年第5期84-88,共5页
We report an experimental study of electron transport properties of MnSe/(Bi,Sb)_2Te_3 heterostructures,in which MnSe is an antiferromagnetic insulator,and(Bi,Sb)_2Te_3 is a three-dimensional topological insulator(TI)... We report an experimental study of electron transport properties of MnSe/(Bi,Sb)_2Te_3 heterostructures,in which MnSe is an antiferromagnetic insulator,and(Bi,Sb)_2Te_3 is a three-dimensional topological insulator(TI).Strong magnetic proximity effect is manifested in the measurements of the Hall effect and longitudinal resistances.Our analysis shows that the gate voltage can substantially modify the anomalous Hall conductance,which exceeds 0.1 e^(2)/h at temperature T=1.6 K and magnetic field μ_0H=5 T,even though only the top TI surface is in proximity to MnSe.This work suggests that heterostructures based on antiferromagnetic insulators provide a promising platform for investigating a wide range of topological spintronic phenomena. 展开更多
关键词 DIRAC Magnetic Proximity Effect in an Antiferromagnetic insulator/Topological insulator Heterostructure with Sharp interface SHARP
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Assessment on gas-polyethylene terephthalate solid interface partial discharge properties of C4F7N/CO_(2)gas mixture for eco-friendly gas insulating transformer
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作者 Song Xiao Yifan Wang +6 位作者 Chenhua Ren Haoran Xia Yue Zhao Jingzi Qin Xiaoxing Zhang Yi Luo Yi Li 《High Voltage》 SCIE EI CSCD 2024年第1期35-45,共11页
The eco-friendly insulating gas perfluoroisobutyronitrile(C_(4)F_(7)N)is potentially used in gas-insulated transformers(GIT)to replace sulphur hexafluoride(SF_(6)).However,evaluation of the long-term insulation reliab... The eco-friendly insulating gas perfluoroisobutyronitrile(C_(4)F_(7)N)is potentially used in gas-insulated transformers(GIT)to replace sulphur hexafluoride(SF_(6)).However,evaluation of the long-term insulation reliability and gas–solid interface discharge decomposition characteristics of the gas–solid film insulation structure in GIT is indispensable.The authors simulated the gas–solid film insulation structure in GIT and explored the interface partial discharge(PD)characteristics of C4F7N/CO_(2)gas mixture with polyethylene terephthalate(PET).The effect of gas pressure,mixing ratio on gas–solid interface gas decomposition,PET degradation was investigated,and the interaction mechanism was analysed.It is found that the interface PD generated three degradation regions on a PET film.The gas–solid interface reaction in the electrode contact region and the discharge development trace was significantly higher than that of halation region.The content of gas decomposition products decreases with the increase of gas pressure and the PD intensity of SF6-PET is inferior to that of C_(4)F_(7)N/CO_(2)under the same condition.Relevant results provide reference for the development and application of C_(4)F_(7)N/CO_(2)based GIT. 展开更多
关键词 interface SOLID insulation
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Research on Effect of Adding Nanomaterial to Propellant on Gun Barrel 被引量:2
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作者 宋遒志 陈永才 《Defence Technology(防务技术)》 SCIE EI CAS 2010年第1期48-53,共6页
The barrel lifes of three small caliber rifles were tested by using the propellant with nanomaterial and the standard propellant respectively. The test results show that the service life increases observably due to ad... The barrel lifes of three small caliber rifles were tested by using the propellant with nanomaterial and the standard propellant respectively. The test results show that the service life increases observably due to adding nanomaterial to the propellant. Then, the influence of the nanomaterial on the tube was researched by splitting the two barrels tested and detecting their inner surfaces. It was found that the erosion of the barrel bore is reduced observably by using the propellant with nanomaterial. And it makes the volume and the size of the gun chamber change less. Therefore, the barrel life can be prolonged by adding the nanomaterial in the propellant. 展开更多
关键词 surface and interface of material barrel life NANOMATERIALS propellant EROSION
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Optimisation method for carbon black distribution of polypropylene-based semi-conductive screen materials and its effect on charge emission behaviour at screen/insulation interface 被引量:2
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作者 Jiaming Yang Rui Zhang +6 位作者 Xu Yang Zhi Sun Xindong Zhao Hong Zhao Xuan Wang Lin Li Heqian Liu 《High Voltage》 SCIE EI CSCD 2023年第2期239-250,共12页
The semi-conductive(SC)screen materials used in polypropylene(PP)-based cables are usually multi-component composites.Polypropylene shows poor compatibility with carbon black(CB),and CB particles tend to disperse in t... The semi-conductive(SC)screen materials used in polypropylene(PP)-based cables are usually multi-component composites.Polypropylene shows poor compatibility with carbon black(CB),and CB particles tend to disperse in the elastomer phase,which results in CB non-uniform dispersion in screen materials.The non-uniform distribution of CB will cause abnormal electric fields at the screen/insulation interface and affect insulation performance.This paper prepared modified PP grafted by molecule maleic anhydride,and four PP-based SC shielding materials were blended in combination with PP,PP-g-MAH,and thermoplastic elastomer(POE)as matrix resin.The CB distribution,electrical conductivity,and basic physical properties of the shielding material were characterised.Different screen materials were served as electrodes to test their effects on the space charge and conductivity characteristics of insulation.The relationship between the macroscopic properties and the distribution characteristics of CB was discussed.Results show that the selective dispersion of CB in screen material was improved by PPg-MAH and the surface electric potential distribution was homogenised.Charge emission at the screen/insulation interface and conductivity can be reduced by homogenising the CB distribution.CB/PP-g-MAH/POE prepared in this paper exhibits relatively uniform CB distribution,which can reduce the charge emission from the screen/insulation interface. 展开更多
关键词 insulation DISTRIBUTION interface
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Fibrous Aerogels with Tunable Superwettability for High-Performance Solar-Driven Interfacial Evaporation
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作者 Chengjian Xu Mengyue Gao +3 位作者 Xiaoxiao Yu Junyan Zhang Yanhua Cheng Meifang Zhu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2023年第5期51-68,共18页
Solar-driven interfacial evaporation is an emerging technology for water desalination.Generally,double-layered structure with separate surface wettability properties is usually employed for evaporator construction.How... Solar-driven interfacial evaporation is an emerging technology for water desalination.Generally,double-layered structure with separate surface wettability properties is usually employed for evaporator construction.However,creating materials with tunable properties is a great challenge because the wettability of existing materials is usually monotonous.Herein,we report vinyltrimethoxysilane as a single molecular unit to hybrid with bacterial cellulose(BC)fibrous network,which can be built into robust aerogel with entirely distinct wettability through controlling assembly pathways.Siloxane groups or carbon atoms are exposed on the surface of BC nanofibers,resulting in either superhydrophilic or superhydrophobic aerogels.With this special property,single component-modified aerogels could be integrated into a double-layered evaporator for water desalination.Under 1 sun,our evaporator achieves high water evaporation rates of 1.91 and 4.20 kg m^(-2)h^(-1)under laboratory and outdoor solar conditions,respectively.Moreover,this aerogel evaporator shows unprecedented lightweight,structural robustness,long-term stability under extreme conditions,and excellent salt-resistance,highlighting the advantages in synthesis of aerogel materials from the single molecular unit. 展开更多
关键词 Cellulose aerogel Tunable wettability Thermal insulation Robust interface Solar vapor generation
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天然酯绝缘油-纸界面的多分支流注放电仿真
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作者 陈刚 辛晓军 +2 位作者 宋普查 王开正 罗莉 《电力工程技术》 北大核心 2024年第4期245-252,共8页
油-纸界面的局部放电是油浸式变压器中油-纸绝缘失效的主要原因之一。文中在多分支流注放电数值模型的基础上进一步考虑油-纸界面的电荷输运特性,构建油-纸绝缘系统中的多分支流注放电模型,并利用有限元法分别对天然酯绝缘油和绝缘纸介... 油-纸界面的局部放电是油浸式变压器中油-纸绝缘失效的主要原因之一。文中在多分支流注放电数值模型的基础上进一步考虑油-纸界面的电荷输运特性,构建油-纸绝缘系统中的多分支流注放电模型,并利用有限元法分别对天然酯绝缘油和绝缘纸介电常数配比、针电极与纸板的间距影响下的沿面放电特性进行研究。结果表明,针电极与纸板的间距及绝缘油与绝缘纸的介电常数配比均会显著影响流注分支;针电极与纸板的间距越小,油-纸界面处的流注分支间的抑制越明显,油-纸界面的流注对z-轴流注的影响更显著;当绝缘油介电常数比纸板大时,流注在油中的发展和分支更为显著,反之则流注更易沿纸板表面发展及在油-纸界面聚集电荷。 展开更多
关键词 天然酯绝缘油 放电模型 流注放电 电场 空间电荷 油-纸界面
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PNIMMO与典型固体推进剂组分表界面作用研究
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作者 郑瑞雪 刘红妮 +4 位作者 周文静 鄂秀天凤 莫洪昌 朱勇 孟子晖 《兵器装备工程学报》 CAS CSCD 北大核心 2024年第1期230-234,共5页
为实现聚3-硝酸酯甲基-3-甲基氧杂环丁烷(PNIMMO)在推进剂配方中的进一步应用,研究了PNIMMO与4种典型固体推进剂组分(RDX、HMX、AP及Al)之间的表界面作用。利用接触角测量仪测定了各组分与不同溶剂的接触角,进而得到了各组分的表面张力... 为实现聚3-硝酸酯甲基-3-甲基氧杂环丁烷(PNIMMO)在推进剂配方中的进一步应用,研究了PNIMMO与4种典型固体推进剂组分(RDX、HMX、AP及Al)之间的表界面作用。利用接触角测量仪测定了各组分与不同溶剂的接触角,进而得到了各组分的表面张力,在此基础上计算了PNIMMO与典型固体推进剂组分的界面张力和黏附功,并推测了其作用机理。结果表明:PNIMMO的表面张力较小,易于在推进剂组分表面铺展。PNIMMO与推进剂组分间的界面张力大小顺序为:γ_(SL)(PNIMMO-AP)>γ_(SL)(PNIMMO-Al)>γ_(SL)(PNIMMO-RDX)>γ_(SL)(PNIMMO-HMX)。PNIMMO与推进剂组分间的黏附功大小顺序为:W_(a)(PNIMMO-AP)>W_(a)(PNIMMO-RDX)>W_(a)(PNIMMO-HMX)>W_(a)(PNIMMO-Al)。PNIMMO与HMX粘结作用最强,与Al粘结作用最弱。与传统粘合剂HTPB相比,PNIMMO有利于改善推进剂的力学性能和流变性能。 展开更多
关键词 物理化学 PNIMMO 推进剂组分 表界面 粘结作用
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10 kV电缆中间接头受潮XLPE-SiR绝缘界面放电演化分析
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作者 黄成龙 赵一枫 +2 位作者 胡冉 刘刚 唐文虎 《广东电力》 北大核心 2024年第6期120-128,共9页
10 kV电缆中间接头交联聚乙烯硅橡胶(XLPE-SiR)绝缘界面在受潮条件下的放电行为严重影响配电网的可靠性,鉴于对绝缘界面放电行为的发展和特征研究较少,分析在受潮条件下10 kV电缆中间接头XLPE-SiR绝缘界面的放电行为,从仿真和试验2个方... 10 kV电缆中间接头交联聚乙烯硅橡胶(XLPE-SiR)绝缘界面在受潮条件下的放电行为严重影响配电网的可靠性,鉴于对绝缘界面放电行为的发展和特征研究较少,分析在受潮条件下10 kV电缆中间接头XLPE-SiR绝缘界面的放电行为,从仿真和试验2个方面验证XLPE-SiR绝缘界面的击穿过程。结果表明:在水分的作用下,XLPE-SiR绝缘界面会出现局部放电,并逐步演变为电弧放电。放电会产生2个影响:一方面引起绝缘材料的热解,形成电痕;另一方面,放电产生的热量导致水蒸发,有效地阻止了绝缘界面处放电的继续。随后,在存在电痕的情况下,进一步研究XLPE-SiR绝缘界面的放电行为。结果表明,当XLPE-SiR绝缘界面存在电痕时,水分的存在会迅速导致绝缘界面击穿。10 kV电缆中间接头绝缘界面受潮直接决定了其绝缘界面放电—短路故障的发展过程,因此在实际电缆中间接头的生产及施工工艺中需要加强防水管控。 展开更多
关键词 电缆中间接头 受潮 XLPE-SiR绝缘界面 局部放电 绝缘界面击穿
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固体推进剂黏弹性参数的确定及细观损伤演化
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作者 乌布力艾散·麦麦提图尔荪 吴艳青 +2 位作者 侯晓 尹欣梅 张鑫 《兵工学报》 EI CAS CSCD 北大核心 2024年第4期1038-1046,共9页
固体推进剂力学模型参数的准确性对其宏观力学响应预测具有重要的意义,为解耦标定固体推进剂非线性黏弹性模型参数,提出一种基于台阶应力松弛试验的模型参数确定方法。通过台阶应力松弛平衡响应确定固体推进剂弹性部分参数,通过小变形... 固体推进剂力学模型参数的准确性对其宏观力学响应预测具有重要的意义,为解耦标定固体推进剂非线性黏弹性模型参数,提出一种基于台阶应力松弛试验的模型参数确定方法。通过台阶应力松弛平衡响应确定固体推进剂弹性部分参数,通过小变形下的应力松弛确定无量纲松弛模量,分析一种固体推进剂力学响应。研究结果表明:固体推进剂在台阶应力松弛及单轴拉伸条件下的力学性能预测结果与试验结果吻合,验证了所提方法的有效性;由于平衡响应包含损伤,采用该方法标定的参数可用于预测含损伤固体推进剂力学响应。在此基础上,提出一种基于推进剂模型参数标定等效黏合剂力学参数的方法,并通过引入基于黏弹性脱湿准则的相界面模型建立代表性体积单元计算模型,实现在宽应变(~100%)范围内推进剂脱湿损伤分析,为推进剂宏观力学性能预测及细观损伤演化分析提供了支撑。 展开更多
关键词 黏弹性模型 参数标定 台阶应力松弛 等效黏合剂 相界面模型 固体推进剂
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界面湿放电下护套ATH填料析出对绝缘子芯棒酥朽老化的影响
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作者 彭雅楠 李文栋 +3 位作者 曾世胤 张宇程 邓禹 张冠军 《高电压技术》 EI CAS CSCD 北大核心 2024年第4期1673-1683,共11页
复合绝缘子中玻璃钢芯棒的酥朽老化现象频繁出现,严重影响了输电线路可靠性。然而,酥朽老化与界面放电的关系尚无明确证据,界面放电下护套粉化对老化的影响仍不明确。文中以内击穿故障而退运绝缘子为参考,搭建了基于界面湿放电的人工加... 复合绝缘子中玻璃钢芯棒的酥朽老化现象频繁出现,严重影响了输电线路可靠性。然而,酥朽老化与界面放电的关系尚无明确证据,界面放电下护套粉化对老化的影响仍不明确。文中以内击穿故障而退运绝缘子为参考,搭建了基于界面湿放电的人工加速老化平台,还原了绝缘子的界面放电和芯棒酥朽老化的发生和发展,并模拟了护套ATH填料析出对于酥朽过程的影响。实验在高湿环境下通过界面放电提供酸性和高温条件,在1000 h的老化过程中,对芯棒样品的微观结构、物理化学性质和泄漏电流进行表征。实验结果表明,多因素环境下的复合绝缘子界面放电会引发芯棒中环氧树脂的分解,最终导致玻璃纤维暴露、断裂,形成酥朽老化。同时,由于界面放电导致的护套ATH填料析出行为虽然会加剧芯棒表面老化;但在长期老化过程中,ATH填料可以部分减缓酥朽老化的深入。硅橡胶护套的耐漏电起痕能力对于减缓芯棒酥朽依然有正向效果,使复合绝缘子拥有一定的自修复性。该研究提供了界面放电引发酥朽老化的实验室基础,有助于监测和理解芯棒老化的发展过程和机理,同时从预防和减缓酥朽老化的角度为护套填料配方提供参考。 展开更多
关键词 复合绝缘子 人工加速老化 芯棒酥朽 界面湿放电 护套填料析出
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绝热层对界面粘接性能影响研究
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作者 黄海龙 李凤宇 +5 位作者 程靖萱 李悦 李东峰 黄丹椿 肖平 尹文奇 《广东化工》 CAS 2024年第8期1-3,10,共4页
本文研究了丁腈橡胶(NBR)和三元乙丙橡胶(EPDM)两类绝热层的种类,以及绝热层的厚度、烘干条件等条件因素对端羟基聚丁二烯(HTPB)/异佛尔酮二异氰酸酯(IPDI)推进剂的界面粘接性能的影响。研究结果表明,NBR绝热层和EPDM绝热层对HTPB/IPDI... 本文研究了丁腈橡胶(NBR)和三元乙丙橡胶(EPDM)两类绝热层的种类,以及绝热层的厚度、烘干条件等条件因素对端羟基聚丁二烯(HTPB)/异佛尔酮二异氰酸酯(IPDI)推进剂的界面粘接性能的影响。研究结果表明,NBR绝热层和EPDM绝热层对HTPB/IPDI推进剂的界面粘接性能均有明显的弱化作用。相比于EPDM绝热层,NBR绝热层对粘接性能的影响更大。随着NBR绝热层厚度的增加,对推进剂界面粘接性能的弱化作用加剧。通过对NBR绝热层的烘干预处理可以减弱绝热层对推进剂界面粘接性能的不利影响。 展开更多
关键词 绝热层 丁腈 三元乙丙 界面粘接
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不同过热故障条件下呋喃分子在油-纸界面扩散行为的分子动力学研究
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作者 徐冉 朱庆东 +2 位作者 李健飞 李华强 王洋 《绝缘材料》 CAS 北大核心 2024年第2期121-128,共8页
呋喃分子是油浸式变压器局部热故障时绝缘纸裂解的重要特征产物之一,变压器油中呋喃分子含量的检测是评估变压器运行状态的重要离线检测手段。为了明确绝缘纸中呋喃分子向植物油中的扩散过程及其与局部过热故障温度标签的对应关系,采用... 呋喃分子是油浸式变压器局部热故障时绝缘纸裂解的重要特征产物之一,变压器油中呋喃分子含量的检测是评估变压器运行状态的重要离线检测手段。为了明确绝缘纸中呋喃分子向植物油中的扩散过程及其与局部过热故障温度标签的对应关系,采用分子动力学的方法,研究了纳米尺度油-纸界面模型在室温(300 K)、低温过热(500 K)、中温过热(750 K)和高温过热(1000 K)条件下呋喃分子从绝缘纸向植物油中的扩散过程。结果表明:随着温度升高,油-纸绝缘中呋喃分子的扩散系数逐渐增大,而且从绝缘纸中扩散到植物油中的呋喃分子数量与温度密切相关。在300 K与500 K的条件下,鲜有呋喃分子扩散到植物油中;而在750 K和1000 K的条件下,部分呋喃分子扩散入植物油中,且温度越高,扩散到植物油中的呋喃分子数越多。上述仿真结果与油浸式变压器中、高温局部过热故障条件下可检测出呋喃族化合物的经验依据一致。 展开更多
关键词 分子模拟 呋喃 油-纸绝缘 界面 扩散
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基于细观参数的HTPB推进剂粘接界面损伤演化数值模拟 被引量:1
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作者 裴书帝 强洪夫 +1 位作者 王学仁 王哲君 《含能材料》 EI CAS CSCD 北大核心 2024年第2期152-161,共10页
为了研究加载角度对三组元端羟基聚丁二烯(HTPB)推进剂粘接界面细观失效机理的影响,使用微CT对单轴拉伸过程中的粘接界面进行原位扫描与重构,表征其损伤演化过程,然后将细观结构参数与损伤变量引入内聚力模型,得到不同加载角度下粘接界... 为了研究加载角度对三组元端羟基聚丁二烯(HTPB)推进剂粘接界面细观失效机理的影响,使用微CT对单轴拉伸过程中的粘接界面进行原位扫描与重构,表征其损伤演化过程,然后将细观结构参数与损伤变量引入内聚力模型,得到不同加载角度下粘接界面的细观损伤演化过程。结果表明,粘接界面高氯酸铵(AP)颗粒的初始脱湿主要从靠近界面的弱界面层开始,方向沿界面的剪切分力方向。界面破坏形式与剪切角度有关,合力与界面的角度越小,裂纹越容易扩展至推进剂/衬层界面,反之裂纹扩展更容易发生在AP颗粒间。通过与CT试验结果对比,从失效模式与载荷位移关系验证了计算结果的准确性,揭示了不同加载角度下推进剂粘接界面结构的损伤演化规律。 展开更多
关键词 固体推进剂 粘接界面 多角度加载 微CT 细观形貌 损伤演化
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GIL支柱绝缘子嵌件-环氧界面缺陷演化过程与放电脆裂机制
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作者 刘智鹏 魏来 +2 位作者 李庆民 薛乃凡 胡琦 《高电压技术》 EI CAS CSCD 北大核心 2024年第1期359-369,共11页
交流GIS/GIL支柱绝缘子在生产、运行过程中其金属嵌件-环氧界面容易引入气隙缺陷,被认为是导致支柱绝缘子炸裂击穿故障的重要诱因。通过设计带有气隙缺陷的支柱绝缘子并搭建炸裂模拟实验平台,研究了绝缘子嵌件-环氧界面缺陷演化与炸裂... 交流GIS/GIL支柱绝缘子在生产、运行过程中其金属嵌件-环氧界面容易引入气隙缺陷,被认为是导致支柱绝缘子炸裂击穿故障的重要诱因。通过设计带有气隙缺陷的支柱绝缘子并搭建炸裂模拟实验平台,研究了绝缘子嵌件-环氧界面缺陷演化与炸裂过程。基于实验研究结果,将支柱绝缘子炸裂过程分为3个特征阶段:裂纹产生与扩展阶段、断裂阶段、炸裂阶段,气隙缺陷引发的局部放电会诱导裂纹的产生与劣化扩展,导致绝缘子在极短的时间内快速断裂并在多次高能电弧冲击下炸裂,呈现脆性断裂的特征。同时,通过实验分析了影响支柱绝缘子炸裂的关键因素,直流电压下绝缘子的炸裂概率比交流电压低10%~20%。进一步构建了电-机械耦合作用下的裂纹扩展相场仿真模型,分析了支柱绝缘子不同炸裂阶段的主导机制。在裂纹的产生与扩展阶段,电势能起到主要作用;在断裂阶段,电势能的作用逐渐减弱,机械势能逐渐增大并起到主导作用,当机械势能达到材料应力临界点时,绝缘子发生脆性炸裂。该研究成果初步揭示了支柱绝缘子气隙缺陷引发的放电脆裂机制,为支柱绝缘子的故障分析及优化设计提供理论基础。 展开更多
关键词 支柱绝缘子 放电脆裂 界面缺陷 缺陷演化 相场仿真
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Fermi level tuning in Sn_(1-x)Pb_(x)Te/Pb heterostructure via changing interface roughness
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作者 Tengteng Liu Zhaoxia Yi +8 位作者 Bangjin Xie Weiyan Zheng Dandan Guan Shiyong Wang Hao Zheng Canhua Liu Hao Yang Yaoyi Li Jinfeng Jia 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2024年第8期118-125,共8页
Superconducting SnTe-type topological crystalline insulators(TCIs)are predicted to host multiple Majorana zero modes(MZMs)which can coexist in a single vortex.Fermi level(FL)close to the Dirac points of topological su... Superconducting SnTe-type topological crystalline insulators(TCIs)are predicted to host multiple Majorana zero modes(MZMs)which can coexist in a single vortex.Fermi level(FL)close to the Dirac points of topological surface states is helpful for detecting MZMs.However,the TCI SnTe is a heavily p-type semiconductor which is very difficult to modify to n-type via doping or alloying.In this work,we fabricate the atomically flat Sn_(1-x)Pb_(x)Te/Pb heterostructure by molecular beam epitaxy,and make the p-type Sn_(1-x)Pb_(x)Te become n-type through changing the interface roughness.Using scanning tunnelling microscope,we find the Dirac points of Sn_(1-x)Pb_(x)Te/Pb heterostructure are always above the FL due to the Fermi level pinning(FLP)induced by topological surface states at atomically flat interface.After increasing the interface roughness,the FLP effect is suppressed and then the Dirac points of p-type Sn_(1-x)Pb_(x)Te can be tuned very close to or even below the FL.Our work provides a new method for tuning the FL of SnTe-type TCI which has potential application in novel topological superconductor device. 展开更多
关键词 topological crystalline insulator SUPERCONDUCTOR HETEROSTRUCTURE Fermi level pinning interface roughness
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Research of cycloaliphatic epoxy resin and silicone rubber composite insulator interface based on four-electrode system and temperature rise model 被引量:1
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作者 Yunsong Wang Yuhao Liu +2 位作者 Hongwei Mei Min Xie Liming Wang 《High Voltage》 SCIE EI CSCD 2023年第3期560-569,共10页
Interface degradation between mandrel and sheath can cause a decrease in insulation performance and mechanical strength of composite insulators.In this study,the interface ageing properties of cycloaliphatic epoxy res... Interface degradation between mandrel and sheath can cause a decrease in insulation performance and mechanical strength of composite insulators.In this study,the interface ageing properties of cycloaliphatic epoxy resin and silicone rubber composite insulator were compared.A water diffusion test was adopted to simulate the composite insulator ageing in a hot and humid environment.A four-electrode system was built to detect leakage current at different locations(mandrel,sheath and interface),which is an important basis for evaluating insulator performance.The ageing degree of insulator could be quantitatively characterised by leakage current change.It was found that the infiltrated moisture had a great effect on insulation performance.Based on the water absorption test result,the interface performance of two insulators was mainly influenced by their sheath sealing quality.As an auxiliary evaluation method,temperature rise during the test was recorded using an infrared camera.The experiment results showed that interface degradation was the main factor for the insulation performance decrease of silicone rubber composite insulators.However,insulation level reduction of the cycloaliphatic epoxy resin was caused by the wet sheath.In addition,a model for temperature rise of cycloaliphatic epoxy resin insulators was proposed based on good correspondence between sheath material and insulation.The model incorporated multiple processes such as ageing and heating of insulators,and it can predict the early temperature rise well. 展开更多
关键词 insulATOR COMPOSITE interface
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复合固体推进剂界面多尺度数值模拟研究进展
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作者 余天昊 闫亚宾 王晓媛 《含能材料》 EI CAS CSCD 北大核心 2024年第5期554-569,共16页
固体推进剂界面作为固体发动机结构中力学性质相对薄弱的部分之一,明确其物化性质、损伤演化模式以及脱湿对推进剂结构完整性的影响是极其重要的研究内容。与实验相比,利用数值模拟能够快速、高效地研究各种界面体系下的不同物化性质,... 固体推进剂界面作为固体发动机结构中力学性质相对薄弱的部分之一,明确其物化性质、损伤演化模式以及脱湿对推进剂结构完整性的影响是极其重要的研究内容。与实验相比,利用数值模拟能够快速、高效地研究各种界面体系下的不同物化性质,具有较好的应用前景。从微观尺度分子动力学、细观尺度有限元数值仿真与宏观数值模拟角度出发,综述了复合固体推进剂多种界面力学性质的研究进展,探讨了多尺度下复合固体推进剂界面数值模拟对固体推进剂工程设计的推动作用与目前存在的不足,并展望了未来的发展方向。 展开更多
关键词 固体推进剂 界面 多尺度 数值模拟
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