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Flexible and Robust Functionalized Boron Nitride/Poly(p‑Phenylene Benzobisoxazole)Nanocomposite Paper with High Thermal Conductivity and Outstanding Electrical Insulation 被引量:1
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作者 Lin Tang Kunpeng Ruan +3 位作者 Xi Liu Yusheng Tang Yali Zhang Junwei Gu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第2期423-437,共15页
With the rapid development of 5G information technology,thermal conductivity/dissipation problems of highly integrated electronic devices and electrical equipment are becoming prominent.In this work,“high-temperature... With the rapid development of 5G information technology,thermal conductivity/dissipation problems of highly integrated electronic devices and electrical equipment are becoming prominent.In this work,“high-temperature solid-phase&diazonium salt decomposition”method is carried out to prepare benzidine-functionalized boron nitride(m-BN).Subsequently,m-BN/poly(pphenylene benzobisoxazole)nanofiber(PNF)nanocomposite paper with nacremimetic layered structures is prepared via sol–gel film transformation approach.The obtained m-BN/PNF nanocomposite paper with 50 wt%m-BN presents excellent thermal conductivity,incredible electrical insulation,outstanding mechanical properties and thermal stability,due to the construction of extensive hydrogen bonds andπ–πinteractions between m-BN and PNF,and stable nacre-mimetic layered structures.Itsλ∥andλ_(⊥)are 9.68 and 0.84 W m^(-1)K^(-1),and the volume resistivity and breakdown strength are as high as 2.3×10^(15)Ωcm and 324.2 kV mm^(-1),respectively.Besides,it also presents extremely high tensile strength of 193.6 MPa and thermal decomposition temperature of 640°C,showing a broad application prospect in high-end thermal management fields such as electronic devices and electrical equipment. 展开更多
关键词 Poly(p-phenylene-2 6-benzobisoxazole)nanofiber Boron nitride thermal conductivity electrical insulation
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Electrospinning-hot pressing technique for the fabrication of thermal and electrical storage membranes and its applications
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作者 Panpan Che Baoshan Xie +7 位作者 Penghui Cao Youfu Lv Daifei Liu Huali Zhu Xianwen Wu Zhangxing He Jian Chen Chuanchang Li 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第9期1945-1964,共20页
The combination of electrospinning and hot pressing,namely the electrospinning-hot pressing technique(EHPT),is an efficient and convenient method for preparing nanofibrous composite materials with good energy storage ... The combination of electrospinning and hot pressing,namely the electrospinning-hot pressing technique(EHPT),is an efficient and convenient method for preparing nanofibrous composite materials with good energy storage performance.The emerging composite membrane prepared by EHPT,which exhibits the advantages of large surface area,controllable morphology,and compact structure,has attracted immense attention.In this paper,the conduction mechanism of composite membranes in thermal and electrical energy storage and the performance enhancement method based on the fabrication process of EHPT are systematically discussed.Moreover,the state-of-the-art applications of composite membranes in these two fields are introduced.In particular,in the field of thermal energy storage,EHPT-prepared membranes have longitudinal and transverse nanofibers,which generate unique thermal conductivity pathways;also,these nanofibers offer enough space for the filling of functional materials.Moreover,EHPT-prepared membranes are beneficial in thermal management systems,building energy conservation,and electrical energy storage,e.g.,improving the electrochemical properties of the separators as well as their mechanical and thermal stability.The application of electrospinning-hot pressing membranes on capacitors,lithium-ion batteries(LIBs),fuel cells,sodium-ion batteries(SIBs),and hydrogen bromine flow batteries(HBFBs)still requires examination.In the future,EHPT is expected to make the field more exciting through its own technological breakthroughs or be combined with other technologies to produce intelligent materials. 展开更多
关键词 electrospinning-hot pressing technique thermal storage electrical storage composite membranes NANOFIBER
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Thermal and Electrical Properties of Liquid Metal Gallium During Phase Transition
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作者 Xizu Wang Durga Venkata Maheswar Repaka +3 位作者 Ady Suwardi Qiang Zhu Jing Wu Jianwei Xu 《Transactions of Tianjin University》 EI CAS 2023年第3期209-215,共7页
Liquid metal gallium has been widely used in numerous fields, from nuclear engineering, catalysts, and energy storage to electronics owing to its remarkable thermal and electrical properties along with low viscosity a... Liquid metal gallium has been widely used in numerous fields, from nuclear engineering, catalysts, and energy storage to electronics owing to its remarkable thermal and electrical properties along with low viscosity and nontoxicity. Compared with high-temperature liquid metals, room-temperature liquid metals, such as gallium(Ga), are emerging as promising alternatives for fabricating advanced energy storage devices, such as phase change materials, by harvesting the advantageous properties of their liquid state maintained without external energy input. However, the thermal and electrical properties of liquid metals at the phase transition are rather poorly studied, limiting their practical applications. In this study, we reported on the physical properties of the solid–liquid phase transition of Ga using a custom-designed, solid–liquid electrical and thermal measurement system. We observed that the electrical conductivity of Ga progressively decreases with an increase in temperature. However, the Seebeck coefficient of Ga increases from 0.2 to 2.1 μV/K, and thermal conductivity from 7.6 to 33 W/(K·m). These electrical and thermal properties of Ga at solid–liquid phase transition would be useful for practical applications. 展开更多
关键词 Liquid metal GALLIUM electrical conductivity thermal conductivity Seebeck coefficients Phase transition
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Mechanical properties,electrical conductivity and microstructure of CuCrZr alloys treated with thermal stretch process 被引量:2
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作者 张蓓 张治国 李卫 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第7期2285-2292,共8页
CuCrZr alloys were treated with the thermal stretch process at various temperatures from 100 to 300℃.The results reveal that the thermal stretch process is successfully developed to manufacture the precipitation hard... CuCrZr alloys were treated with the thermal stretch process at various temperatures from 100 to 300℃.The results reveal that the thermal stretch process is successfully developed to manufacture the precipitation hardening CuCrZr alloys with a good combination of microhardness and electrical conductivity.By increasing the tensile elongations at each temperature from 100 to 300℃,the microhardness increases whereas the electrical conductivity decreases slightly.Cr-containing precipitate phases with a Nishiyama-Wasserman orientation relationship to the copper matrix were observed by TEM.The achievement of high micro-hardness and acceptable electrical conductivity in the thermal stretch treated alloys is ascribed to the interactions of the heteroatom solution,dislocation increment,grain refinement and dispersive precipitation effect. 展开更多
关键词 CuCrZr alloys thermal stretch treatment MICROHARDNESS electrical conductivity
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Effects of carbonaceous conductive fillers on electrical and thermal properties of asphalt-matrix conductive composites
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作者 周晓锋 张小松 周建成 《Journal of Southeast University(English Edition)》 EI CAS 2013年第1期88-91,共4页
The relationship between thermal/electrical conductivity enhancement in asphalt-matrix mixtures and the properties of filling conductive particles is studied. The thermal properties with filling the carbon fiber, grap... The relationship between thermal/electrical conductivity enhancement in asphalt-matrix mixtures and the properties of filling conductive particles is studied. The thermal properties with filling the carbon fiber, graphite conductive particles in asphalt-matrix mixtures are investigated. Based on the generalized effective medium theory ( EMT ), the effective thermal and electrical conductivity of carbon fiber/asphalt and graphite/asphalt composites are theoretically elucidated. The theoretical results are found to be in reasonably well agreement with the experimental data. Moreover, the theoretical and experimental results show that the large-aspect-ratio shape of particles can help to achieve a large enhancement of effective conductivity, and the use of disk-like high conductivity particles can limit the additive contents for preserving the volumetric properties and mechanical properties of asphalt composites. The generalized effective medium theory model can be used for predicting the thermal and electrical properties of asphaltmatrix composites, which is still available for most of the thermal/electrical modifications in two-phase composites. 展开更多
关键词 carbonaceous conductive fillers asphalt-matrix composites thermal conductivity electrical conductivity
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Enhanced thermal and electrical properties of poly (D,L-lactide)/ multi-walled carbon nanotubes composites by in-situ polymerization 被引量:5
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作者 李清华 周勤华 +4 位作者 邓丹 俞巧珍 谷俐 龚科达 徐科航 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第5期1421-1427,共7页
Biodegradable poly (D,L-lactide) (PLA)/carboxyl-functionalized multi-walled carbon nanotubes (c-MWCNTs) composites were achieved via in-situ polymerization. These as-prepared composite materials were characteriz... Biodegradable poly (D,L-lactide) (PLA)/carboxyl-functionalized multi-walled carbon nanotubes (c-MWCNTs) composites were achieved via in-situ polymerization. These as-prepared composite materials were characterized with FT-IR, XRD, TG, DSC, SEM, and high insulation resistance meter. The results demonstrate that the multi-walled carbon nanotube was carboxyl functionalized, which improved the collection between c-MWCNTs and PLA, and further realized the graft copolymerization of c-MWCNTs and PLA. There is a higher glass transition temperature and a lower pyrolysis temperature of PLA/c-MWCNTs composites than pure PLA. The c-MWCNTs gave a better dispersion than unmodified MWCNTs in the PLA matrix, and an even coating of PLA on the surface of c-MWCNTs was obtained, which increased the interfacial interaction. High insulation resistance analysis showed that the addition of c-MWCNTs increased the electric conductivity, and c-MWCNTs performed against the large dielectric coefficient and electrostatic state of PLA. These results demonstrated that c-MWCNTs modified PLA composites were beneficial for potential application in the development of heat-resisting and conductivity plastic engineering. 展开更多
关键词 in-situ polymerization multi-walled carbon nanotubes POLYLACTIDE thermal properties electrical conductivity
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Reinforcement Learning-Based Electric Vehicles Energy Management Strategy with Battery Thermal Model 被引量:1
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作者 黄淦 曹童杰 +2 位作者 韩俊华 赵萍 张光林 《Journal of Donghua University(English Edition)》 CAS 2023年第1期80-87,共8页
The promotion of electric vehicles(EVs)is restricted due to their short cruising range.It is desirable to design an effective energy management strategy to improve their energy efficiency.Most existing work concerning... The promotion of electric vehicles(EVs)is restricted due to their short cruising range.It is desirable to design an effective energy management strategy to improve their energy efficiency.Most existing work concerning energy management strategies focused on hybrids rather than the EVs.The work focusing on the energy management strategy for EVs mainly uses the traditional optimization strategies,thereby limiting the advantages of energy economy.To this end,a novel energy management strategy that considered the impact of battery thermal effects was proposed with the help of reinforcement learning.The main idea was to first analyze the energy flow path of EVs,further formulize the energy management as an optimization problem,and finally propose an online strategy based on reinforcement learning to obtain the optimal strategy.Additionally,extensive simulation results have demonstrated that our strategy reduces energy consumption by at least 27.4%compared to the existing methods. 展开更多
关键词 energy management electric vehicle(EV) reinforcement learning battery thermal management
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Preparation of Poly(p-phenylene sulfide)/Carbon Composites with Enhanced Thermal Conductivity and Electrical Insulativity via Hybrids of Boron Nitride and Carbon Fillers 被引量:2
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作者 吴介立 WANG Jinwen 陈枫 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2015年第3期562-567,共6页
The present work enhanced the thermal conductivity of poly(p-phenylene sulfide)/expanded graphites and poly(p-phenylene sulfide)/carbon nanotubes, by incorporating composites with hexagonal boron nitride, which si... The present work enhanced the thermal conductivity of poly(p-phenylene sulfide)/expanded graphites and poly(p-phenylene sulfide)/carbon nanotubes, by incorporating composites with hexagonal boron nitride, which simultaneously succeeded in raising the electrical conductivity of the systems. A two-step mechanical processing method which includes rotating solid-state premixing and inner mixing was adopted to improve dispersion of the hybrids, contributing to the formation of an interspered thermal conductive network. Similar synergic effect in thermal conductivity enhancement was discovered in the hybrid systems regardless of the dimension difference between the two carbon fillers. Such is postulated to be the one satisfying advantage generated by the afore-mentioned network; the other is the insulativity of the hybrid systems given by the effective blockage of hexagonal boron nitride as an insulating material in our network. 展开更多
关键词 hBN CNT EG rotating solid-state premixing thermal conductivity electrical insulativity dispersion
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Thermal stability and electrical properties of copper nitride with In or Ti 被引量:2
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作者 杜允 高磊 +1 位作者 李超荣 纪爱玲 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第6期494-499,共6页
Thin films of ternary compounds CuxlnyN and CuxTiyN were grown by magnetron sputtering to improve the thermal stability of Cu3N, a material that decomposes below 300 ℃, and thus promises many interesting applications... Thin films of ternary compounds CuxlnyN and CuxTiyN were grown by magnetron sputtering to improve the thermal stability of Cu3N, a material that decomposes below 300 ℃, and thus promises many interesting applications in directwriting. The effect of In or Ti incorporation in altering the structure and physical properties of copper nitride was evaluated by characterizing the film structure, surface morphology, and temperature dependence of electrical resistivity. More Ti than In can be accommodated by copper nitride without completely deteriorating the Cu3N lattice. A small amount of In or Ti can improve the crystallinity, and consequently the surface morphology. While the decomposition temperature is rarely influenced by In, the Ti-doped sample, Cu59.31Ti2.64N38.05, shows an X-ray diffraction pattern dominated by characteristic Cu3N peaks, even after annealing at 500 ℃. Both In and Ti reduce the bandgap of the original Cu3N phase, resulting in a smaller electrical resistivity at room temperature. The samples with more Ti content manifest metal-semiconductor transition when cooled from room temperature down to 50 K. These results can be useful in improving the applicability of copper-nitride-based thin films. 展开更多
关键词 ternary nitride thin film thermal stability electrical properties
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Electrical conductivity changes of bulk tin and Sn-3.0Ag-0.5Cu in bulk and in joints during isothermal aging 被引量:2
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作者 Bin Liu Fu Guo 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2010年第4期453-458,共6页
The changes of electrical conductivity (resistance) between Sn-3.0Ag-0.5Cu solder joints and printed circuit board (PCB) assembly during aging at 125℃ were investigated by the four-point probe technique. The micr... The changes of electrical conductivity (resistance) between Sn-3.0Ag-0.5Cu solder joints and printed circuit board (PCB) assembly during aging at 125℃ were investigated by the four-point probe technique. The microstructural characterizations of interfacial layers between the solder matrix and the substrate were examined by optical microscopy and scanning electronic microscopy. Different types of specimens were designed to consider several factors. The experimental results indicate that electrical conductivities (resistances) and residual shear strengths of the solder joint specimens significantly decrease after 1000 h during isothermal aging. Microcracks generate in the solder matrix at the first 250 h. Besides, the evolutions of microstructural characterizations at the interface and the matrix of solder joints were noted in this research. 展开更多
关键词 lead-free solder electrical conductivity isothermal aging microcrack thermal stress
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Effects of filler loading and surface modification on electrical and thermal properties of epoxy/montmorillonite composite 被引量:3
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作者 Zi-Rui Jia Zhen-Guo Gao +3 位作者 Di Lan Yong-Hong Cheng Guang-Lei Wu Hong-Jing Wu 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第11期332-339,共8页
Epoxy-based composites containing montmorillonite(MMT)modified by silylation reaction withγ-aminopropyltriethoxysilane(γ-APTES)and 3-(glycidyloxypropyl)trimethoxysilane(GPTMS)are successfully prepared.The effects of... Epoxy-based composites containing montmorillonite(MMT)modified by silylation reaction withγ-aminopropyltriethoxysilane(γ-APTES)and 3-(glycidyloxypropyl)trimethoxysilane(GPTMS)are successfully prepared.The effects of filler loading and surface modification on the electrical and thermal properties of the epoxy/MMT composites are investigated.Compared with the pure epoxy resin,the epoxy/MMT composite,whether MMT is surface-treated or not,shows low dielectric permittivity,low dielectric loss,and enhanced dielectric strength.The MMT in the epoxy/MMT composite also influences the thermal properties of the composite by improving the thermal conductivity and stability.Surface functionalization of MMT not only conduces to the better dispersion of the nanoparticles,but also significantly affects the electric and thermal properties of the hybrid by influencing the interfaces between MMT and epoxy resin.Improved interfaces are good for enhancing the electric and thermal properties of nanocomposites.What is more,the MMT modified with GPTMS rather thanγ-APTES is found to have greater influence on improving the interface between the MMT filler and polymer matrices,thus resulting in lower dielectric loss,lower electric conductivity,higher breakdown strength,lower thermal conductivity,and higher thermal stability. 展开更多
关键词 modified epoxy resin surface modification electric property thermal property
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Thermal spin molecular logic gates modulated by an electric field
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作者 谭兴毅 李强 任达华 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第5期591-595,共5页
Logic gates are fundamental structural components in all modern digital electronic devices. Here, nonequilibrium Green's functions are incorporated with the density functional theory to verify the thermal spin tra... Logic gates are fundamental structural components in all modern digital electronic devices. Here, nonequilibrium Green's functions are incorporated with the density functional theory to verify the thermal spin transport features of the single-molecule spintronic devices constructed by a single molecule in series or parallel connected with graphene nanoribbons electrodes. Our calculations demonstrate that the electric field can manipulate the spin-polarized current. Then, a complete set of thermal spin molecular logic gates are proposed, including AND, OR, and NOT gates. The mentioned logic gates enable different designs of complex thermal spin molecular logic functions and facilitate the electric field control of thermal spin molecular devices. 展开更多
关键词 thermal spin molecular logic gates electric field SINGLE-MOLECULE
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Electrical, Thermal, and Mechanical Properties of Cu/Ti3AlC2 Functional Gradient Materials Prepared by Low-temperature Spark Plasma Sintering 被引量:1
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作者 CHEN Yanlin WU Chonggang 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2019年第4期876-882,共7页
Cu/Ti3AlC2 composite and functional-gradient materials with excellent electrical conductivity and thermal conductivity as well as good flexural properties were prepared by low-temperature spark plasma sintering of Cu ... Cu/Ti3AlC2 composite and functional-gradient materials with excellent electrical conductivity and thermal conductivity as well as good flexural properties were prepared by low-temperature spark plasma sintering of Cu and Ti3AlC2 powder mixtures. The phase compositions of the materials were analyzed by X-ray diffraction, and their microstructure was characterized by scanning electron microscopy and energy dispersive X-ray spectroscopy. Further, the electrical conductivity, thermal conductivity, and flexural properties of the materials were tested. Results show that, for the composite materials, the resistivity rises from 0.75 × 10^-7 Ω·m only to 1.32 × 10^-7 Ω·m and the thermal diffusivity reduces from 82.5 mm^2/s simply to 39.8 mm^2/s, while the flexural strength improves from 412.9 MPa to 471.3 MPa, as the content of Ti3AlC2 is increased from 5 wt%to 25 wt%. Additionally, the functional-gradient materials sintered without interface between the layers exhibit good designability, and their overall electrical conductivity, thermal conductivity, and flexural strength are all higher than those of the corresponding uniform composite material. 展开更多
关键词 Cu/Ti3AlC2 FUNCTIONAL gradient material electrical CONDUCTIVITY thermal CONDUCTIVITY
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Effect of retained austenite and nonmetallic inclusions on the thermal/electrical properties and resistance spot welding nuggets of Si-containing TRIP steels 被引量:1
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作者 V.H.Vargas I.Mejía +1 位作者 V.H.Baltazar-Hernández C.Maldonado 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2019年第1期52-63,共12页
Five advanced high-strength transformation-induced plasticity(TRIP) steels with different chemical compositions were studied to correlate the retained austenite and nonmetallic inclusion content with their physical pr... Five advanced high-strength transformation-induced plasticity(TRIP) steels with different chemical compositions were studied to correlate the retained austenite and nonmetallic inclusion content with their physical properties and the characteristics of the resistance spot welding nuggets. Electrical and thermal properties and equilibrium phases of TRIP steels were predicted using the JMatPro? software. Retained austenite and nonmetallic inclusions were quantified by X-ray diffraction and saturation magnetization techniques. The nonmetallic inclusions were characterized by scanning electron microscopy. The results show that the contents of Si, C, Al, and Mn in TRIP steels increase both the retained austenite and the nonmetallic inclusion contents. We found that nonmetallic inclusions affect the thermal and electrical properties of the TRIP steels and that the differences between these properties tend to result in different cooling rates during the welding process. The results are discussed in terms of the electrical and thermal properties determined from the chemical composition and their impact on the resistance spot welding nuggets. 展开更多
关键词 transformation-induced plasticity steel RETAINED austenite non-metallic inclusions magnetic saturation electrical PROPERTIES thermal PROPERTIES resistance spot welding NUGGET
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Electrical,thermal and electrochemical properties of γ-ray-reduced graphene oxide 被引量:1
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作者 M.M.Atta H.A.Ashry +1 位作者 G.M.Nasr H.A.Abd El-Rehim 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2021年第10期1726-1734,共9页
The properties of γ-ray-reduced graphene oxide samples(GRGOs)were compared with those of hydrazine hydrate-reduced graphene oxide(HRGO).Fourier transform infrared spectroscopy,X-ray diffractometry,Raman spectroscopy,... The properties of γ-ray-reduced graphene oxide samples(GRGOs)were compared with those of hydrazine hydrate-reduced graphene oxide(HRGO).Fourier transform infrared spectroscopy,X-ray diffractometry,Raman spectroscopy,Brunauer-Emmett-Teller surface area analysis,thermogravimetric analysis,electrometry,and cyclic voltammetry were carried out to verify the reduction process,structural changes,and defects of the samples,as well as to measure their thermal,electrical,and electrochemical properties.Irradiation with γ-rays distorted the structure of GRGOs and generated massive defects through the extensive formation of new smaller sp^(2)-hybridized domains compared with those of HRGO.The thermal stability of GRGOs was higher than that of HRGO,indicating the highly efficient removal of thermally-labile oxygen species by γ-rays.RRGO prepared at 80 kGy showed a pseudocapacitive behavior comparable with the electrical double-layer capacitance behavior of HRGO.Interestingly,the specific capacitance of GRGO was enhanced by nearly three times compared with that of HRGO.These results reflect the advantages of radiation reduction in energy storage applications. 展开更多
关键词 GRAPHENE Γ-RAY electrical thermal electrOCHEMICAL
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Mechanical, electrical, and thermal expansion properties of carbon nanotube-based silver and silver–palladium alloy composites 被引量:3
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作者 Hemant Pal Vimal Sharma 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2014年第11期1132-1140,共9页
The mechanical, electrical, and thermal expansion properties of carbon nanotube(CNT)-based silver and silver–palladium(10:1, w/w) alloy nanocomposites are reported. To tailor the properties of silver, CNTs were ... The mechanical, electrical, and thermal expansion properties of carbon nanotube(CNT)-based silver and silver–palladium(10:1, w/w) alloy nanocomposites are reported. To tailor the properties of silver, CNTs were incorporated into a silver matrix by a modified molecular level-mixing process. CNTs interact weakly with silver because of their non-reactive nature and lack of mutual solubility. Therefore, palladium was utilized as an alloying element to improve interfacial adhesion. Comparative microstructural characterizations and property evaluations of the nanocomposites were performed. The structural characterizations revealed that decorated type-CNTs were dispersed, embedded, and anchored into the silver matrix. The experimental results indicated that the modification of the silver and silver–palladium nanocomposite with CNT resulted in increases in the hardness and Young's modulus along with concomitant decreases in the electrical conductivity and the coefficient of thermal expansion(CTE). The hardness and Young's modulus of the nanocomposites were increased by 30%?40% whereas the CTE was decreased to 50%-60% of the CTE of silver. The significantly improved CTE and the mechanical properties of the CNT-reinforced silver and silver–palladium nanocomposites are correlated with the intriguing properties of CNTs and with good interfacial adhesion between the CNTs and silver as a result of the fabrication process and the contact action of palladium as an alloying element. 展开更多
关键词 metal matrix composites carbon nanotubes mechanical properties coefficient of thermal expansion electrical conductivity
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Influence of heat loss through probe electrical leads on thermal conductivity measurement with TPS method 被引量:2
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作者 WANG Yu-wei LI Yan-ning 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2018年第1期9-15,共7页
The transient plane source(TPS)method is developed recently to measure the thermal conductivity of materials.In the measurement,the heating power is influenced by the heat which is transferred via the probe electrical... The transient plane source(TPS)method is developed recently to measure the thermal conductivity of materials.In the measurement,the heating power is influenced by the heat which is transferred via the probe electrical leads.This fact further influences the measurement accuracy of thermal conductivity.To solve this problem,the influence of heat loss through the electrical leads on the heating power is studied theoretically.The mathematical formula of heat loss is deduced,and the corresponding correction model is presented.A series of measurement experiments on different materials have been conducted by using the hot disk thermal constant analyzer.The results show that the influence of the heat loss on the measurement is sensitive to different test materials and probes with different sizes.When the thermal conductivity of the material is greater than 0.2 W/(m·K),the influence of the heat loss is less than 0.16%,which can be ignored.As to the lower thermal conductivity materials,it is necessary to compensate the heat loss through the electrical leads,and the accuracy of thermal conductivity measurement can be effectively improved. 展开更多
关键词 transient plane source(TPS)method thermal conductivity heat loss through electrical leads heating power
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On the Electrical and Thermal Conductivities of Cast A356/Al<sub>2</sub>O<sub>3</sub>Metal Matrix Nanocomposites 被引量:1
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作者 El-Sayed Youssef El-Kady Tamer Samir Mahmoud Ali Abdel-Aziz Ali 《Materials Sciences and Applications》 2011年第9期1180-1187,共8页
To assess the effect of the dispersion of Al2O3 nanoparticles into A356 Al alloy on both the electrical and thermal conductivities, A356/Al2O3 metal matrix nanocomposites (MMNCs) were fabricated using a combination of... To assess the effect of the dispersion of Al2O3 nanoparticles into A356 Al alloy on both the electrical and thermal conductivities, A356/Al2O3 metal matrix nanocomposites (MMNCs) were fabricated using a combination of rheocasting and squeeze casting techniques. Two different sizes of Al2O3 nanoparticles were dispersed into the A356 Al alloy, typically, 60 and 200 nm with volume fractions up to 5 vol%. The effect of the nanoparticles size and volume fraction on the electrical and thermal conductivities was evaluated. The results revealed that the A356 monolithic alloy exhibited better electrical and thermal conductivities than the MMNCs. Increasing the nanoparticles size and/or the volume fraction reduces both the thermal and electrical conductivities of the MMNCs. The maximum reduction percent in the thermal and electrical conductivities, according to the A356 monolithic alloy, were about 47% and 38%, respectively. Such percentages were exhibited by A356/Al2O3MMNCs containing 5 vol% of nanoparticles having 60 and 200 nm, respectively. 展开更多
关键词 NANOCOMPOSITES thermal CONDUCTIVITY electrical CONDUCTIVITY Aluminum Alloys
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Thermal Distortion Compensation for Improving Electrical Performance of Reflector Antennas 被引量:1
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作者 Jiamei Kang Wei Wang +2 位作者 Shuo Zhang Shaofan Lian Hong Bao 《Open Journal of Applied Sciences》 2021年第4期523-540,共18页
Aiming at the problem of the surface accuracy and electrical performance of the antenna in space environment are reduced due to thermal deformation caused by temperature load. This paper presents a method to compensat... Aiming at the problem of the surface accuracy and electrical performance of the antenna in space environment are reduced due to thermal deformation caused by temperature load. This paper presents a method to compensate the thermally induced shape distortion of antenna reflector by actively adjusting actuators in order to improve the electrical performance. The adjustment of each actuator is related to the local deformation of the panel. Then, taking a space deployable antenna with a diameter of 5 meters as an example, the finite element model is established. According to the range of the temperature variation in space (<span style="white-space:nowrap;">&#8722;</span>180<span style="white-space:nowrap;">&#176;</span>C - 200<span style="white-space:nowrap;">&#176;</span>C), different temperature loads are applied to the antenna. The variation of electrical properties and surface accuracy is analyzed and the worst working condition is determined, and the antenna is compensated based on this condition. Then, four different electrical performance parameters are used as the optimization objectives, and the electromechanical coupling optimization model is established, and the PSO algorithm is used to optimize the actuators adjustments. The results show that the method can effectively improve the electrical performance of the deformed reflector antenna. 展开更多
关键词 Space Reflector Antenna thermal Distortion Active Compensation electrical Performance PSO
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Concentration and Temperature Dependence of Electrical Conductivity in Thermally Stable Chromium Polyacrylate 被引量:2
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作者 S. U.Rehman M.Siddique and Farid A.Khwaja(Materials Research Laboratory, Dept. of Physics, Quaid-i-Azam University, Islamabad, Pakistan)M.S.Zafar(Dept. of Physics, University of the Punjab, Lahore, Pakistan) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1995年第6期443-446,共4页
Electrical conductivity of chromium polyacrylate with dopant concentration 30, 40 and 50 wt-% of chromium has been measured over a broad range of temperatures (303 K to 383 K).The electrical conductivity shows depende... Electrical conductivity of chromium polyacrylate with dopant concentration 30, 40 and 50 wt-% of chromium has been measured over a broad range of temperatures (303 K to 383 K).The electrical conductivity shows dependence on temperature, as well as, level of doping. The conductivity is considered to be due to thermal hopping motion of localized charge carriers,which are believed to be polarons, in the temperature range 303 K to 323 K and for T>343 K,whereas. it is metal-like in the temperature range 323 K to 343 K 展开更多
关键词 Concentration and Temperature Dependence of electrical Conductivity in thermally Stable Chromium Polyacrylate
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