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Effects of the Thickness Ratio of CrN vs Cr_2O_3 Layer on the Properties of Double-layered CrN/Cr_2O_3 Coatings Deposited by Arc Ion Plating 被引量:2
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作者 Chang-Ming Shi Tie-Gang Wang +2 位作者 Zhi-Liang Pei Jun Gong Chao Sun 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2014年第5期473-479,共7页
In this study, CrN/Cr2O3 double-layered coatings with various thickness ratios of CrN vs Cr2O3 layer were prepared by arc ion plating technology. The influences of the thickness ratio of CrN vs Cr2O3 layer on the micr... In this study, CrN/Cr2O3 double-layered coatings with various thickness ratios of CrN vs Cr2O3 layer were prepared by arc ion plating technology. The influences of the thickness ratio of CrN vs Cr2O3 layer on the microstructural characteristics as well as the mechanical and tribological properties of the CrN/Cr2O3 doublelayered coatings were investigated. The corresponding mechanisms were also discussed. The results indicated that the insertion of CrN layer between the Cr2O3 layer and substrate can effectively decrease the internal stress level of the coating. With increasing the thickness ratio of CrN vs Cr2O3 layer, the surface roughness of double-layered coatings decreased gradually, which had a certain influence on the friction coefficient. In addition, the microhardness also declined gradually, the adhesive strength almost increased linearly, whereas the wear rate declined firstly and then increased slightly. As the thickness ratio was 2:1, the double-layered coating exhibited the best wear resistance. 展开更多
关键词 Cr2O3/CrN double-layered coating thickness ratio Arc ion plating Mechanical property Wear
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Diffusion Coefficient at Double Resonances in Frequency and Temperature, Applied to (n+/p/p+) Silicon Solar Cell Base Thickness Optimization under Long Wavelength Illumination
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作者 Gora Diop Ousmane Sow +6 位作者 Moustapha Thiame Richard Mane Ibrahima Diatta Khady Loum Sega Gueye Mamadou Wade Gregoire Sissoko 《Journal of Electromagnetic Analysis and Applications》 CAS 2022年第8期89-103,共15页
The diffusion coefficient of the minority charge carriers in the base of a silicon solar cell under temperature and subjected to a magnetic field, passes in reso-nance at temperature (T<sub>opt</sub>). For... The diffusion coefficient of the minority charge carriers in the base of a silicon solar cell under temperature and subjected to a magnetic field, passes in reso-nance at temperature (T<sub>opt</sub>). For this same magnetic field, the diffusion coeffi-cient of the photogenerated carriers by a monochromatic light in frequency modulation enters into resonance, at the frequency (ω<sub>c</sub>). Under this double resonance in temperature and frequency, the diffusion coefficient is used in the expression of the recombination velocity of the minority charge carriers on the back side of the base of the solar cell (n<sup>+</sup>/p/p<sup>+</sup>), to obtain, by a graphical method, the optimum thickness. A modeling of the results obtained shows a material saving (Si), in the development of the solar cell. 展开更多
关键词 Silicon Solar Cell-diffusion Coefficient Recombination Velocity Absorption Coefficient Magnetic Field-Temperature-thickness
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Association of Optic Radiation Integrity with Cortical Thickness in Children with Anisometropic Amblyopia 被引量:13
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作者 Shun Qi Yun-Feng Mu +7 位作者 Long-Biao Cui Rong Li Mei Shi Ying Liu Jun-Qing Xu Jian Zhang Jian Yang Hong Yin 《Neuroscience Bulletin》 SCIE CAS CSCD 2016年第1期51-60,共10页
Previous studies have indicated regional abnormalities of both gray and white matter in amblyopia. However, alterations of cortical thickness associated with changes in white matter integrity have rarely been reported... Previous studies have indicated regional abnormalities of both gray and white matter in amblyopia. However, alterations of cortical thickness associated with changes in white matter integrity have rarely been reported. In this study, structural magnetic resonance imaging and diffusion tensor imaging (DTI) data were obtained from 15 children with anisometropic amblyopia and 15 age- and gender-matched children with normal sight. Combining DTI and surface-based morphometry, we examined a potential linkage between disrupted white matter integrity and altered cortical thickness. The fractional anisotropy (FA) values in the optic radiations (ORs) of children with anisometropic amblyopia were lower than in controls (P 〈 0.05). The cortical thickness in amblyopic children was lower than controls in the following subregions: lin- gual cortex, lateral occipitotemporal gyrus, cuneus, occip- ital lobe, inferior parietal lobe, and temporal lobe (P 〈 0.05, corrected), but was higher in the calcarine gyrus (P 〈 0.05, corrected). Node-by-node correlation analysis of changes in cortical thickness revealed a significant association between a lower FA value in the OR and diminished cortical thickness in the following subregions: medial lingual cortex, lateral occipitotemporal gyrus, lat- eral, superior, and medial occipital cortex, and lunate cortex. We also found a relationship between changes of cortical thickness and white matter OR integrity in amblyopia. These findings indicate that developmental changes occur simultaneously in the OR and visual cortex in amblyopia, and provide key information on complex damage of brain networks in anisometropic amblyopia. Our results also support the hypothesis that the pathogenesis of anisometropic amblyopia is neurodevelopmental. 展开更多
关键词 Optic radiation - Cortical thickness diffusion tensor imaging Anisometropic amblyopiaChildren
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Effect of Deposition Time on Thickness and Corrosion Behavior of Zn-Fe Coating 被引量:4
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作者 LIU Li YU Sirong 《Journal of Shanghai Jiaotong university(Science)》 EI 2019年第3期395-401,共7页
Zn-Fe coatings on Q235 steel are prepared by pack cementation process at 390 ℃ for 2,4,6,8 and10 h to investigate the effects of the deposition time on the thickness and corrosion behavior of the Zn-Fe coatings.The t... Zn-Fe coatings on Q235 steel are prepared by pack cementation process at 390 ℃ for 2,4,6,8 and10 h to investigate the effects of the deposition time on the thickness and corrosion behavior of the Zn-Fe coatings.The thickness of the coating increases with the increase of the deposition time.The coating is composed of a thick outer layer and a thin inner layer.The formation of the coating depends on the inward diffusion of Zn atoms and the outward diffusion of Fe atoms.The outer layer is composed of Fe11 Zn40 and FeZn10 phases.The corrosion behavior of the Zn-Fe coatings is evaluated by immersion test and polarization test.The results show that the Zn-Fe coatings can effectively prevent the Q235 steel from corrosion.The corrosion resistance of the coating is proportional to the deposition time. 展开更多
关键词 ZN pack cementation thickness diffusION corrosion resistance
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Surface Recombination Concept as Applied to Determinate Silicon Solar Cell Base Optimum Thickness with Doping Level Effect 被引量:2
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作者 Masse Samba Diop Hamet Yoro Ba +6 位作者 Ndeye Thiam Ibrahima Diatta Youssou Traore Mamadou Lamine Ba El Hadji Sow Oulymata Mballo Grégoire Sissoko 《World Journal of Condensed Matter Physics》 2019年第4期102-111,共10页
New expressions of back surface recombination of excess minority carriers in the base of silicon solar are expressed dependent on both, the thickness and the diffusion coefficient which is in relationship with the dop... New expressions of back surface recombination of excess minority carriers in the base of silicon solar are expressed dependent on both, the thickness and the diffusion coefficient which is in relationship with the doping rate. The optimum thickness thus obtained from the base of the solar cell allows the saving of the amount of material needed in its manufacture without reducing its efficiency. 展开更多
关键词 Silicon Solar Cell Surface Recombination VELOCITY diffusION COEFFICIENT DOPING Rate BASE thickness
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Influence of Both Magnetic Field and Temperature on Silicon Solar Cell Base Optimum Thickness Determination 被引量:1
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作者 Nouh Mohamed Moctar Ould Mohamed Ousmane Sow +7 位作者 Sega Gueye Youssou Traore Ibrahima Diatta Amary Thiam Mamour Amadou Ba Richard Mane Ibrahima Ly Gregoire Sissoko 《Journal of Modern Physics》 2019年第13期1596-1605,共10页
The minority carrier’s recombination velocity at the junction and at the back surface is used for the modeling and determination of the optimum thickness of the base of a silicon solar cell in the static regime, unde... The minority carrier’s recombination velocity at the junction and at the back surface is used for the modeling and determination of the optimum thickness of the base of a silicon solar cell in the static regime, under magnetic field and temperature influence. This study takes into account the Umklapp process and the Lorentz effect on the minority carriers photogenerated in the base. 展开更多
关键词 Silicon Solar Cell diffusion COEFFICIENT Surface Recombination Velocity OPTIMUM BASE thickness LORENTZ and Umklapp Processes
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Electrochemical process of sulfur in carbon materials from electrode thickness to interlayer
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作者 Xiaonan Tang Zhenhua Sun +5 位作者 Huicong Yang Haitao Fang Fei Wei Hui-Ming Cheng Shuping Zhuo Feng Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2019年第4期119-124,共6页
Lots of efforts have been done on different porous carbon materials as cathode for Lithium–sulfur(Li–S)battery. However, seldom researches have been done on the relationship between cathode thickness and electrochem... Lots of efforts have been done on different porous carbon materials as cathode for Lithium–sulfur(Li–S)battery. However, seldom researches have been done on the relationship between cathode thickness and electrochemical performance. Our work investigates the relation between electrochemical performance and cathode thickness with typical porous carbon materials. We explain the phenomenon that only a modest cathode thickness can have the most adequate electrochemical reaction trend through the aspect of thermodynamics(chemical potential) so that the best electrochemical performance can be obtained.Besides, interlayer can remit the shuttle effect but hinder the lithium ion diffusion process simultaneously. And we verify the effect of interlayer thickness on the shuttle effect and lithium ion diffusion process. 展开更多
关键词 Lithium-sulfur battery ELECTROCHEMICAL reaction CATHODE thickness Chemical potential Ion diffusion
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Regulation of the Reacted Layer Thickness in a Gas-Solid Reacting System
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作者 Miguel A. Barron Dulce Y. Medina Gabriel Plascencia 《Intelligent Control and Automation》 2014年第3期91-96,共6页
A mathematical model for the analysis of a gas-solid reacting system is presented. This model is an alternative to the classical shrinking-core model. The model has a structure that can be easily transformed into a ca... A mathematical model for the analysis of a gas-solid reacting system is presented. This model is an alternative to the classical shrinking-core model. The model has a structure that can be easily transformed into a canonical control form, which is proper for controller synthesis. Analytical solution of the model to describe the open-loop behavior is expressed in terms of the Lambert function. The Lambert function is evaluated from aTaylorexpansion series. Besides, a controller is proposed to regulate the reacted layer thickness using initially the diffusion coefficient as control input. The control law is synthesized employing the feedback linearization technique. Main contributions of this work are the synthesis of the layer thickness controller, and the employment of the process temperature as substitute of the diffusion coefficient as the control input. 展开更多
关键词 diffusion COEFFICIENT FEEDBACK LINEARIZATION GAS-SOLID SYSTEM Lambert Function Reacted Layer thickness REGULATION
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Influences of diffusion bonding process parameters on bond characteristics of Mg-Cu dissimilar joints 被引量:12
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作者 G. MAHENDRAN V. BALASUBR AMANIAN T. SENTHILVELAN 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第6期997-1005,共9页
In many circumstances,dissimilar metals have to be bonded together and the resulting joint interfaces must typically sustain mechanical and/or electrical forces without failure,which is not possible by fusion welding ... In many circumstances,dissimilar metals have to be bonded together and the resulting joint interfaces must typically sustain mechanical and/or electrical forces without failure,which is not possible by fusion welding processes.The melting points of magnesium(Mg)and copper(Cu)have a significant difference(nearly 400℃)and this may lead to a large difference in the microstructure and joint performance of Mg-Cu joints.However,diffusion bonding can be used to join these alloys without much difficulty.This work analyses the effect of parameters on diffusion layer thickness,hardness and strength of magnesium-copper dissimilar joints.The experiments were conducted using three-factor,five-level,central composite rotatable design matrix.Empirical relationships were developed to predict diffusion layer thickness,hardness and strength using response surface methodology.It is found that bonding temperature has predominant effect on bond characteristics.Joints fabricated at a bonding temperature of 450℃, bonding pressure of 12 MPa and bonding time of 30 min exhibited maximum shear strength and bonding strength of 66 and 81 MPa, respectively. 展开更多
关键词 diffusion bonding magnesium alloy copper alloy shear strength bonding strength diffusion layer thickness interface hardness
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Influence of secondary lining thickness on mechanical behaviours of double-layer lining in large-diameter shield tunnels 被引量:2
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作者 Shimin Wang Xuhu He +3 位作者 Xiaoyu Peng Ya Wang Zhengxin Li Zihan 《Underground Space》 SCIE EI CSCD 2024年第5期130-150,共21页
In large-diameter shield tunnels,applying the double-layer lining structure can improve the load-bearing properties and maintain the stability of segmental lining.The secondary lining thickness is a key parameter in t... In large-diameter shield tunnels,applying the double-layer lining structure can improve the load-bearing properties and maintain the stability of segmental lining.The secondary lining thickness is a key parameter in the design of a double lining structure,which is worth being explored.Based on an actual large-diameter shield tunnel,loading model tests are carried out to investigate the effect of the secondary lining thickness on the mechanical behaviours of the double lining structure.The test results show that within the range of secondary lining thicknesses discussed,the load-bearing limit of the double-layer lining increases with growing secondary lining thickness.As a passive support,the secondary lining acts as an auxiliary load-bearing structure by contacting the segment.And changes in secondary lining thickness have a significant effect on the contact state between the segment and secondary lining,with both the contact pressure level and the contact area between the two varying.For double-layer lining structures in large-diameter shield tunnels,it is proposed that the stiffness of the secondary lining needs to be matched to the stiffness of the segment,as this allows them to have a coordinated deformation and a good joint load-bearing effect. 展开更多
关键词 Large-diameter shield tunnels double-layer lining structure Secondary lining thickness Stiffness matching Similar model test
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Effect of plastic deformation on diffusion-rolling bonding of steel sandwich plates 被引量:1
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作者 Hong Li Jingtao Han 《Journal of University of Science and Technology Beijing》 CSCD 2006年第6期532-537,共6页
Diffusion bonding is one of the most important techniques for composite materials, while bonding temperature, holding time,and rolling reduction are the key parameters that affect the bonding strength of sandwich plat... Diffusion bonding is one of the most important techniques for composite materials, while bonding temperature, holding time,and rolling reduction are the key parameters that affect the bonding strength of sandwich plates. To study the effect of plastic deformation on the bonding strength, laboratory experiments were carried on a Gleeble Thermal Simulator to imitate the diffusion-rolling bonding under different reductions for steel sandwich plates. The bonding strength and interlayer film thickness were measured, and the element diffusion was analyzed using line scanning. The relationship between the bonding strength and “diffused interlayer” thickness was investigated. It has been found that the bonding strength increases with reduction, whereas the interlayer film thickness decreases gradually as the reduction increases. The diffusion under plastic deformation is obviously enhanced in comparison with that of nil reduction. The mechanism of plastic deformation effect on the diffusion bonding and related models have been discussed. 展开更多
关键词 steel sandwich plate diffusion-bonding plastic deformation bonding strength interlayer film thickness diffusion mechanism models
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Influence of Alternative Magnetic Field on the Diffusion of Al and Mg
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作者 Xiaotao LIU, Jianzhong CUI, Yanhui GUO, Xiaoming WU and Jun ZHANGThe Key Laboratory of Electromagnetic Processing of Materials, Ministry of Education, Northeastern University, Shenyang 110004, China 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2004年第4期457-459,共3页
The influence of an alternative magnetic field on the diffusion of Al and Mg in AI-Mg diffusion couple is studied. The diffusion zone is composed of two intermediate phases, namelyβ and γ phase. Thickness of each in... The influence of an alternative magnetic field on the diffusion of Al and Mg in AI-Mg diffusion couple is studied. The diffusion zone is composed of two intermediate phases, namelyβ and γ phase. Thickness of each intermediate phase is examined. The results show that the alternative magnetic field increases the thicknesses of βand γ phase zone and the layer growth ofβ and γphase obeys the parabolic rate law. The growth rate of the β and γ phase are increased with the application of the alternative magnetic field. This change is manifested through a change in the frequency factor k0 and not through a change in the activation energy Q. The frequency factor k0 for intermediate phase growth with an alternative magnetic field is 39.95 cm2/s for 7 phase and 2.84×10-4 cm2/s for β phase compared with those without the magnetic field is 22.4 cm2/s for 7 phase and 1.53×10-4 cm2/s for β phase. 展开更多
关键词 Alternative magnetic field Al-Mg Couple Intermediate phase thickness diffusION
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Effect of alternative magnetic field on the diffusion layer growth in Al/Zn couple
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作者 LIUXiaotao CUIJianzhong WUXiaoming GUOYanhui ZHANGJun 《Rare Metals》 SCIE EI CAS CSCD 2004年第3期246-249,共4页
The influence of an alternative magnetic field on the growth of the diffusionlayer in Al-Zn diffusion couple was studied. The thickness of the diffusion layer was examined. Theresults show that the alternative magneti... The influence of an alternative magnetic field on the growth of the diffusionlayer in Al-Zn diffusion couple was studied. The thickness of the diffusion layer was examined. Theresults show that the alternative magnetic field increases the thickness of the diffusion layer andthe effect increases with the intensity and frequency of the alternative magnetic field increasing. The growth of the diffusion layer obeys the parabolic rate law and the growth rateincreases with the application of the alternative magnetic field. This growth rate change ismanifested through a change in the frequency factor k_0 and not through a change in the activationenergy Q. The frequency factor k_0 for the diffusion layer growth with the alternative magneticfield is 5.03 cm^2/s and the one without the magnetic field is 3.84 cm^2/s. 展开更多
关键词 alternative magnetic field Al-Zn couple diffusion zone thickness parabolic rate law
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酸碱溶液作用下膨胀土力学特性与微观机理研究
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作者 胡波 李伟 +3 位作者 马琨 袁瑞祥 王帅 孙慧 《长江科学院院报》 北大核心 2025年第7期199-206,213,共9页
为了研究酸碱赋存条件对膨胀土力学特性的影响,选取引江济淮工程C003标段膨胀土,通过自制的淋滤试验装置进行不同pH值酸碱溶液的膨胀土淋滤试验,基于界限含水率试验、三轴固结排水剪切试验探究膨胀土强度变化与溶液pH值的关系,并通过化... 为了研究酸碱赋存条件对膨胀土力学特性的影响,选取引江济淮工程C003标段膨胀土,通过自制的淋滤试验装置进行不同pH值酸碱溶液的膨胀土淋滤试验,基于界限含水率试验、三轴固结排水剪切试验探究膨胀土强度变化与溶液pH值的关系,并通过化学成分、X射线衍射分析物理力学特性变化的内在机理。结果表明:经酸性溶液淋滤后土体液塑限呈减小趋势,抗剪强度随pH值减小出现明显劣化;经碱性溶液淋滤后土体液塑限呈增大趋势,抗剪强度随pH值增大出现明显增强。微观试验发现,经酸性溶液作用后颗粒扩散层厚度变薄,胶结物遭到溶蚀,土体结构变差,因此,淋滤后试样表面存在孔洞,力学特性随pH值减小逐渐劣化;经碱性溶液作用后颗粒扩散层厚度变厚,土体体积出现膨胀,新生成的胶结物充填内部大小孔隙,土体结构变密实,因此,力学特性随pH值增大逐渐增强。 展开更多
关键词 膨胀土 淋滤 酸碱溶液 抗剪强度 扩散层厚度
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高温高压下石榴斜长角闪岩的热物理性质研究及其对岩石圈热结构的约束 被引量:1
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作者 马玮宇 易丽 +6 位作者 王多君 张瑞鑫 韩珂楠 张瑞 魏靓 薛攀明 唐学武 《地球物理学报》 北大核心 2025年第2期609-622,共14页
高温高压下矿物和岩石的热导率与热扩散系数可以为地质过程的热演化历史模拟提供数据支撑,同时也是建立稳定状态下的深部圈层热结构的必要参数.本文选取下地壳中具备较高代表性的石榴斜长角闪岩,利用基于六面顶压机上的瞬态平面热源法... 高温高压下矿物和岩石的热导率与热扩散系数可以为地质过程的热演化历史模拟提供数据支撑,同时也是建立稳定状态下的深部圈层热结构的必要参数.本文选取下地壳中具备较高代表性的石榴斜长角闪岩,利用基于六面顶压机上的瞬态平面热源法测试系统,测量了其在0.5~1.5 GPa、300~973 K下的热导率与热扩散系数,结果发现热导率和热扩散系数随温度增加而降低,随压力增加而升高,温度对热导率和热扩散系数的影响远大于压力的影响.在固定压力下,热导率和热扩散系数随温度的变化最大可达40%,在固定温度下,压力对热导率和热扩散系数的影响最大可达23%.利用实验获得的数据,结合前人的高温高压数据与热岩石圈模型参数,计算了不同地表热流下华北克拉通不同区域的热岩石圈厚度范围. 展开更多
关键词 高温高压 石榴斜长角闪岩 热导率 热扩散系数 热岩石圈厚度
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石墨烯厚膜热扩散系数与微观结构的关系
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作者 白天琦 黄坤 +5 位作者 刘法辰 时若晨 任文才 裴嵩峰 高鹏 刘忠范 《物理化学学报》 北大核心 2025年第3期85-93,共9页
电子元件集成度的快速提升对器件热管理提出了更高的要求。石墨烯凭借其出色的导热性能成为备受关注的材料之一。目前制备高热导率石墨烯厚膜的主流方法是将氧化石墨烯组装成膜再还原,尽管前人的研究取得了突出成效,但截止目前仍未能完... 电子元件集成度的快速提升对器件热管理提出了更高的要求。石墨烯凭借其出色的导热性能成为备受关注的材料之一。目前制备高热导率石墨烯厚膜的主流方法是将氧化石墨烯组装成膜再还原,尽管前人的研究取得了突出成效,但截止目前仍未能完全理解石墨烯膜内部缺陷结构对热导率的具体影响机制,这将限制热导率的进一步提升,达到或超过1500 W·m^(-1)·K^(-1)。在氧化石墨烯膜的热还原过程中,不可避免地会形成一些孔洞结构,通过降低整体密度的方式降低热导率。热扩散系数作为决定热导率大小的另一因素,孔洞对其影响因素却尚未被研究过。在这里,我们定义了包含孔洞的石墨烯膜材料特有的本征热扩散系数,并通过多种电子显微学方法、热扩散系数的测试和有限元模拟,详细研究了石墨烯厚膜的本征热扩散系数与微观结构之间的关联。我们旨在阐明孔洞对热扩散系数以及热导率的影响方式和作用机制。研究结果揭示了不同尺寸和数量的孔洞对热扩散系数的影响,发现密集小孔洞结构可使热扩散系数降低39.4%,而同等面积的单一大孔洞结构对热扩散系数的降低仅约16.1%。通过三维重构获得的统计结论也与计算结果完全匹配。其内在机制是密集小孔洞结构的存在对原有传热路径的破坏更为严重,而单一大孔洞结构的这一作用则相对较弱,只是降低了整体密度从而降低热导率。此外,研究发现面外结晶性对热扩散系数有显著影响,进一步增进了对影响热扩散系数的微观机理的认识。通过阐明这些机制,我们的研究加深了对石墨烯厚膜微观结构与热学性能关联的理解,为生产超高热导率的石墨烯厚膜提供了重要信息,也为下一代电子器件热管理解决方案提供了有效策略。 展开更多
关键词 石墨烯厚膜 本征热扩散系数 单一大孔洞 密集小孔洞 面外结晶性
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Sn-0.3Ag-0.7Cu合金焊膏瞬时液相扩散焊接铜接头的界面组织及剪切性能
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作者 孔子斌 张宁 +2 位作者 贺新语 夏晴 袁鑫 《机械工程材料》 北大核心 2025年第11期49-54,共6页
在两块紫铜基板之间均匀涂覆20μm厚度Sn-0.3Ag-0.7Cu合金焊膏,在不同回流温度(240,260,280℃)和不同回流时间(0,1,2,3,4,8 h)下进行瞬时液相扩散焊试验,研究了不同工艺接头的界面组织和剪切性能。结果表明:在回流温度240℃下随着回流... 在两块紫铜基板之间均匀涂覆20μm厚度Sn-0.3Ag-0.7Cu合金焊膏,在不同回流温度(240,260,280℃)和不同回流时间(0,1,2,3,4,8 h)下进行瞬时液相扩散焊试验,研究了不同工艺接头的界面组织和剪切性能。结果表明:在回流温度240℃下随着回流时间延长,接头界面的金属间化合物Cu_(6)Sn_(5)先增加后减少,形貌由扇贝状转变为层状;当回流时间为4 h时,焊缝中几乎填满Cu_(6)Sn_(5),焊缝与母材界面处形成Cu3Sn金属化合物薄层,当回流时间为8 h时焊缝中出现较大孔洞,Cu3Sn金属化合物层厚度增加。界面金属间化合物层的厚度随回流时间延长或回流温度升高先增大后减小,其生长符合体扩散特征,扩散系数随回流温度升高而增大。接头的剪切强度随回流时间延长先升后降,当回流时间为4 h时剪切强度最高;回流温度对剪切强度影响不大。 展开更多
关键词 Sn-0.3Ag-0.7Cu合金焊料 显微组织 金属间化合物层 扩散系数
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Estimating the thickness of diffusive solid electrolyte interface 被引量:1
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作者 XiaoHe Wang WenHao Shen +2 位作者 XianFu Huang JinLiang Zang YaPu Zhao 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2017年第6期61-68,共8页
electrolyte. The properties of lithium-ion (Li-ion) battery, such as cycle life, irreversible capacity loss, self-discharge rate, electrode corrosion and safety are usually ascribed to the quality of the SEI, which ar... electrolyte. The properties of lithium-ion (Li-ion) battery, such as cycle life, irreversible capacity loss, self-discharge rate, electrode corrosion and safety are usually ascribed to the quality of the SEI, which are highly dependent on the thickness. Thus, understanding the formation mechanism and the SEI thickness is of prime interest. First, we apply dimensional analysis to obtain an explicit relation between the thickness and the number density in this study. Then the SEI thickness in the initial charge-discharge cycle is analyzed and estimated for the first time using the Cahn-Hilliard phase-field model. In addition, the SEI thickness by molecular dynamics simulation validates the theoretical results. It has been shown that the established model and the simulation in this paper estimate the SEI thickness concisely within order-of-magnitude of nanometers. Our results may help in evaluating the performance of SEI and assist the future design of Li-ion battery. 展开更多
关键词 lithium-ion battery solid electrolyte interface diffusion model thickness estimation
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堆垛冷却方式对连铸特厚板坯氢去除的影响研究
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作者 王卫华 王凯凯 +1 位作者 刘洋 马长文 《轧钢》 北大核心 2025年第4期134-142,共9页
为了提高连铸特厚板坯探伤合格率,降低厚板生产成本和预防“白点”、“氢脆”、“点状偏析”等质量缺陷,克服传统实验手段检测特厚板坯氢扩散的难点,通过数值模拟的方法,研究了通过堆垛冷却方式使钢中氢浓度降低到安全范围的工艺,取得... 为了提高连铸特厚板坯探伤合格率,降低厚板生产成本和预防“白点”、“氢脆”、“点状偏析”等质量缺陷,克服传统实验手段检测特厚板坯氢扩散的难点,通过数值模拟的方法,研究了通过堆垛冷却方式使钢中氢浓度降低到安全范围的工艺,取得了良好的效果。由于连铸坯厚达400 mm,氢从其芯部扩散到表面所需时间较长,普通堆垛缓冷无法满足铸坯排氢的效果,采用缓冷坑以及缓冷坑加热方式进行堆垛缓冷,能进一步提升铸坯保温效果,从而使铸坯氢扩散更加充分。为此,建立了基于3种堆垛方式下的铸坯氢扩散数学模型,比较了普通堆垛、缓冷坑堆垛、缓冷坑加热3种堆垛冷却方式对铸坯氢扩散的影响,得到铸坯各位置处氢含量和除氢速率。普通堆垛、缓冷坑堆垛、缓冷坑加热3种堆垛形式下,底层铸坯的除氢率分别为58.93%、67.63%、71.98%。缓冷坑堆垛方式和缓冷坑加热方式不仅更有利于特厚板坯氢的扩散,而且可使特厚板坯上、下表面氢扩散更加均匀。 展开更多
关键词 堆垛方式 特厚板坯 缓冷坑 氢扩散 有限元 数值模拟 除氢速率
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防爆墙对某厂区LPG管网泄漏-爆炸事故后果的影响
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作者 王秋红 杜孙薇 +3 位作者 董国强 罗振敏 张明广 薛云帆 《西安科技大学学报》 北大核心 2025年第4期716-725,共10页
应用FLACS软件对陕西某石化厂区LPG管网泄漏引发的爆炸事故危害进行定量研究,通过在装置区与生活办公区之间增设防爆墙来减缓爆炸风险。通过防爆墙的位置D(指防爆墙与生活办公区最左侧边缘的间距)、高度H和厚度d来研究防爆墙的爆炸减缓... 应用FLACS软件对陕西某石化厂区LPG管网泄漏引发的爆炸事故危害进行定量研究,通过在装置区与生活办公区之间增设防爆墙来减缓爆炸风险。通过防爆墙的位置D(指防爆墙与生活办公区最左侧边缘的间距)、高度H和厚度d来研究防爆墙的爆炸减缓效果。结果表明:防爆墙离爆源越远,离生活办公区越近,对生活办公区的防护效果越好;对于该石化厂区生活办公区内的24 m建筑物,防爆墙距生活办公区域5 m、防爆墙高度分别是3 m和11 m时,对应的墙后爆炸超压降幅分别为52.20%和70.33%;防爆墙厚度d分别为0.1,0.3,0.5和0.7 m时,对应的墙后爆炸超压降幅分别为68.29%、67.44%、66.80%和66.41%。对于刚性结构防爆墙而言,防爆墙高度对墙后爆炸超压降低效果比防爆墙厚度更显著,防爆墙高度的设计对爆炸的防爆与防控更关键。模拟结果对该石化厂区事故的超前防护提供了方法。 展开更多
关键词 液化石油气 泄漏扩散 爆炸风险分析 防爆墙位置 防爆墙高度 防爆墙厚度
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