期刊文献+

二次检索

题名
关键词
文摘
作者
第一作者
机构
刊名
分类号
参考文献
作者简介
基金资助
栏目信息
共找到538篇文章
< 1 2 27 >
每页显示 20 50 100
EFFECT OF DISPERSED PHASE PARTICLES ON ELECTRICAL CONDUCTION OF PEO-NaSCN
1
《Chemical Research in Chinese Universities》 SCIE CAS 1986年第1期97-101,共5页
Fast ionic conductors are one kind of solid state material with ionic conductivity as high as that of melten salts or liquid electrolytes.Ionic conductivity is one of the important parameters for characterizing a fast... Fast ionic conductors are one kind of solid state material with ionic conductivity as high as that of melten salts or liquid electrolytes.Ionic conductivity is one of the important parameters for characterizing a fast ionic conductor.For a long time materialists and chemists have made great efforts in search of new fast ionic conductors with high ionic conductivity.In view of structure,they have synthesised silver and copper fast ionic conductors with so called open structures.But it is not so successful for searching more applicable alkaline fast ionic conductors.Since polymer has flexibility for making thin film,it concentrates attention on the polymer-alkaline salt complex.Fenton et al.have first reported poly(ethylene oxide) (PEO)-alkaline salt complex.Later on Armard et al.have investigated the electrical property of PEO-NaSCN. 展开更多
关键词 OC PEO EFFECT OF DISPERSED PHASE PARTICLES ON electrical conduction OF PEO-NaSCN
下载PDF
Electrical Conduction in Deuterated Ammonium Dihydrogen Phosphate Crystals with Different Degrees of Deuteration
2
作者 朱丽丽 甘笑雨 +6 位作者 张清华 刘宝安 徐明霞 张立松 许心光 顾庆天 孙洵 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第5期107-110,共4页
Conductivity measurements of deuterated ammonium dihydrogen phosphate (DADP) crystals with different deuterated degrees are described. The conductivities increase with the deuterium content, and the value of the a-d... Conductivity measurements of deuterated ammonium dihydrogen phosphate (DADP) crystals with different deuterated degrees are described. The conductivities increase with the deuterium content, and the value of the a-direction is larger than that of the e-direction. Compared with DKDP crystals, DADP crystals have larger conductivities, which is partly due to the existence of A defects. The ac conductivity over the temperature range 25-170℃has shown a knee in the curve ofln(σT) versus T-1. The conductivity activation energy calculated by the slope of the high temperature region decreases with the deuterium content. The previously reported phase transition is not seen. 展开更多
关键词 electrical conduction in Deuterated Ammonium Dihydrogen Phosphate Crystals with Different Degrees of Deuteration ADP
下载PDF
A three-dimensional polycyclic aromatic hydrocarbon based covalent organic framework doped with iodine for electrical conduction
3
作者 Ruofan Li Guolong Xing +2 位作者 Hui Li Shen Li Long Chen 《Chinese Chemical Letters》 SCIE CAS CSCD 2023年第4期601-604,共4页
Covalent organic frameworks(COFs) are a class of crystalline porous organic materials with variable structures and fascinating properties. The intrinsic low conductivity impedes their widely application in optoelectro... Covalent organic frameworks(COFs) are a class of crystalline porous organic materials with variable structures and fascinating properties. The intrinsic low conductivity impedes their widely application in optoelectronic. Iodine doping is an effective way to enhance the electrical conductivity of COFs. Here, a novel 3D imine COF with lvt topology is synthesized from two different pentacene derivatives with the same core in the form of structural complementarity. DDHP-COF is a highly crystalline material featuring high surface area of 1679 m^(2)/g and excellent thermal stability up to 490 ℃. Upon doping with iodine, the electrical conductivity can reach as high as 1.5×10^(-2)S/m which is significantly enhanced over 6 orders of magnitude compared with the pristine COF. 展开更多
关键词 THREE-DIMENSIONAL Covalent organic frameworks Imine linkage Chemical doping electrical conduction
原文传递
Dielectric,electrical conduction and magnetic properties of multiferroic Bi_(0.8)Tb_(0.1)Ba_(0.1)Fe_(0.9)Ti_(0.1)O_(3)perovskite compound
4
作者 Poonam Kumari Radheshyam Rai +1 位作者 Seema Sharma M.A.Valente 《Journal of Advanced Dielectrics》 CAS 2017年第5期47-56,共10页
This work focuses on the structural,electrical and magnetic properties of Bi_(0.8)Tb_(0.1)Ba_(0.1)Fe_(0.9)Ti_(0.1)O_(3)ceramics,fabricated by solid state reaction procedure.XRD forms of the samples at RT exhibited per... This work focuses on the structural,electrical and magnetic properties of Bi_(0.8)Tb_(0.1)Ba_(0.1)Fe_(0.9)Ti_(0.1)O_(3)ceramics,fabricated by solid state reaction procedure.XRD forms of the samples at RT exhibited perovskite phase through the hexagonal structure at room temperature.Dielectric studies of the materials with frequency at different temperatures(25-400℃)exhibit two dielectric anomalies,first at 175℃(ferroelectric-ferroelectric transition)and second at around 320℃(ferroelectric-paraelectric transition).The Curie temperature moved towards the low side temperature with the increase in frequency.The less value of activation energy got for these samples could be attributed to the influence of electronic contribution to the conductivity.A significant change in the magnetic studies was observed for Bi_(0.8)Tb_(0.1)Ba_(0.1)Fe_(0.9)Ti_(0.1)O_(3) ceramic.The impedance analysis confirms the non-Debye type nature of the ceramic and relaxation frequency moved to a higher temperature.The Nyquist plot and conductivity studies showed the NTCR behavior of samples.The highest magnetization field was found at temperature-268.15℃. 展开更多
关键词 Lead-free ceramics X-ray difraction(XRD) phase transitions electrical conduction magnetic properties MULTIFERROICS
原文传递
Saturation Estimation with Complex Electrical Conductivity for Hydrate-Bearing Clayey Sediments:An Experimental Study 被引量:1
5
作者 XING Lanchang ZHANG Shuli +8 位作者 ZHANG Huanhuan WU Chenyutong WANG Bin LAO Liyun WEI Wei HAN Weifeng WEI Zhoutuo GE Xinmin DENG Shaogui 《Journal of Ocean University of China》 CAS CSCD 2024年第1期173-189,共17页
Clays have considerable influence on the electrical properties of hydrate-bearing sediments.It is desirable to understand the electrical properties of hydrate-bearing clayey sediments and to build hydrate saturation(S... Clays have considerable influence on the electrical properties of hydrate-bearing sediments.It is desirable to understand the electrical properties of hydrate-bearing clayey sediments and to build hydrate saturation(S_(h))models for reservoir evaluation and monitoring.The electrical properties of tetrahydrofuran-hydrate-bearing sediments with montmorillonite are characterized by complex conductivity at frequencies from 0.01 Hz to 1 kHz.The effects of clay and Sh on the complex conductivity were analyzed.A decrease and increase in electrical conductance result from the clay-swelling-induced blockage and ion migration in the electrical double layer(EDL),respectively.The quadrature conductivity increases with the clay content up to 10%because of the increased surface site density of counterions in EDL.Both the in-phase conductivity and quadrature conductivity decrease consistently with increasing Sh from 0.50 to 0.90.Three sets of models for Sh evaluation were developed.The model based on the Simandoux equation outperforms Archie’s formula,with a root-mean-square error(E_(RMS))of 1.8%and 3.9%,respectively,highlighting the clay effects on the in-phase conductivity.The fre-quency effect correlations based on in-phase and quadrature conductivities exhibit inferior performance(E_(RMS)=11.6%and 13.2%,re-spectively)due to the challenge of choosing an appropriate pair of frequencies and intrinsic uncertainties from two measurements.The second-order Cole-Cole formula can be used to fit the complex-conductivity spectra.One pair of inverted Cole-Cole parameters,i.e.,characteristic time and chargeability,is employed to predict S_(h) with an E_(RMS) of 5.05%and 9.05%,respectively. 展开更多
关键词 gas hydrate complex electrical conductivity hydrate-bearing clayey sediment hydrate saturation Simandoux equation frequency dispersion Cole-Cole formula
下载PDF
Electrical conduction properties of the BZT-BST ceramics
6
作者 Satyanarayan Patel Harekrishna Yadav 《Journal of Advanced Dielectrics》 CAS 2020年第6期1-13,共13页
0.5Ba(Zr_(0.2)Ti_(0.8))O3-0.5(Ba_(0.7)Sr_(0.3))TiO3(BZT-BST)has been explored in recent times for potential applications in energy harvesting,electrocaloric and energy storage.To this end,energy harvesting/conversion ... 0.5Ba(Zr_(0.2)Ti_(0.8))O3-0.5(Ba_(0.7)Sr_(0.3))TiO3(BZT-BST)has been explored in recent times for potential applications in energy harvesting,electrocaloric and energy storage.To this end,energy harvesting/conversion and storage applications require an understanding of the conduction and loss mechanisms.The conduction mechanism in BZT-BST ceramics is studied using impedance spectroscopy(IS)at 0.1 Hz−3 MHz and 100−600°C.Impedance study reveals the presence of two types of relaxation processes due to grain and grain boundary contributions.The relaxation time and dc conductivity activation energies are obtained as 1.12/1.3 eV and 1.05/1.2eV for bulk/grain boundary,respectively,and found that oxygen vacancies dominated electrical behavior.The relaxation mechanism follows non-Debye-type behavior.The high resistance of the grain(bulk)in the ferroelectric region does not contribute to the high losses;the losses probably result from the phase transition.Also,BZT-BST ceramics exhibit a negative temperature coefficient of resistance(NTCR)behaviour.From a practical application point of view in the temperature regime of 25-65°C,the loss’s contri-bution is low.The significant contributions of loss result from the response of phase-transition in this temperature range(25-65°C)。 展开更多
关键词 electrical conductivity impedance spectroscopy electric modulus lead-free.
原文传递
ELECTRONIC ENERGY BAND STRUCTURE OF MOLECULAR CRYSTALS MCI·(TCNQ)_2 AND ITS RELATIONSHIP WITH THE ELECTRICAL CONDUCTION
7
作者 张启元 严继民 《Science China Chemistry》 SCIE EI CAS 1990年第10期1163-1171,共9页
The structure of electronic energy bands, electric charge distribution and the amount of charge transfer of molecular crystals 1-MCI·(TCNQ)_2 (Ⅰ) and 2-MCI· (TCNQ)_2 (Ⅱ) have been studied. The results are... The structure of electronic energy bands, electric charge distribution and the amount of charge transfer of molecular crystals 1-MCI·(TCNQ)_2 (Ⅰ) and 2-MCI· (TCNQ)_2 (Ⅱ) have been studied. The results are: (ⅰ) The dominant contributions to the electrical conductivities for crystals Ⅰ and Ⅱ are from TCNQ molecular columns, and the charge carriers are electrons. (ⅱ) The electrical conduction is mainly due to the hopping of charge carriers between the seats of lattice. (ⅲ) The considerable difference of the electrical conductivities between crystals Ⅰ and Ⅱ is due to the differences between (a) the concentrations of charge carriers n_(AⅠ)~C= 0.9988-|e|/cell and n_(AⅡ)~C=0.0340-|e|/cell; (b) the widths of the energy bands △E_(AⅠ)^(LU)=0.88 eV and △E_(AⅡ)~LU=0.040 eV; (c) the first derivative of E with respect to k, (dE/dk)_(K_FAⅠ)^(LU)=0.27 eV· and (dE/dk)_(K_FAⅡ)~LU=0.0048 eV·; and (d) the difference of energy barriers for the hopping of charge carriers ∈_Ⅱ-∈Ⅰ=2.5-8.8 kJ/mol. 展开更多
关键词 structure of electronic energy bands energy bands and the electrical conductivities molecular crystal MIC·(TCNQ)_2
原文传递
STUDY ON THE STRUCTURE, ELECTRICAL PROPERTIES AND CONDUCTION MECHANISM 0F THE MULTICRYSTAL MULTIPHASE MATERIAL Li_2MO_2-xWxO_6
8
作者 崔万秋 沈志其 周德保 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 1990年第2期15-21,共7页
The conductivity of non-crystalline fast ionic conductor for B_2O_3-Li_2O-LiCl-Al_2O_3 system is studiedin this paper. The glass structure of this system is discussed by means of infrared spectrum and X-ray fluorescen... The conductivity of non-crystalline fast ionic conductor for B_2O_3-Li_2O-LiCl-Al_2O_3 system is studiedin this paper. The glass structure of this system is discussed by means of infrared spectrum and X-ray fluorescence analysis, and the effects of LiCl and A1_2O_3 on the conductivity of Li^+ in the system are studied as well. Adding Li_2O to the system gives rise to transfer from [BO_3] triangular units to [BO_4] tetrahedral. When Li_2O content exceeds 30mol%, the main group of the glass is the diborate group with more [BO_4] tetrahedra. The adding of LiCl has no obvious influence on the glass structure, and LiCl is under a state dissociated by network, but with the increase of LiCl, the increase of conductivity is obvious. By adding A1_2O_3, the glass can be formed when the room-temperature is cooling down,the conductivity decreases while the conductive activatory energy increases for the glass. The experiment shows that conductivity in the room-temperature is σ= 6.2×10^(-6)Ω^(-1)cm^(-1), when at 300℃, the σ=6.8×10^(-3)Ω^(-1)cm^(-1). The conductive activatory energy computed is 0.6~1.0eV. 展开更多
关键词 MO MO LI OC STUDY ON THE STRUCTURE electrical PROPERTIES AND conduction MECHANISM 0F THE MULTICRYSTAL MULTIPHASE MATERIAL Li2MO2-xWxO6 ESR
下载PDF
Influence of anisotropy on the electrical conductivity and diffusion coefficient of dry K-feldspar: Implications of the mechanism of conduction
9
作者 代立东 胡海英 +2 位作者 李和平 孙文清 蒋建军 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第2期630-639,共10页
The electrical conductivities of single-crystal K-feldspar along three different crystallographic directions are investigated by the Solartron-1260 Impedance/Gain-phase analyzer at 873 K–1223 K and 1.0 GPa–3.0 GPa i... The electrical conductivities of single-crystal K-feldspar along three different crystallographic directions are investigated by the Solartron-1260 Impedance/Gain-phase analyzer at 873 K–1223 K and 1.0 GPa–3.0 GPa in a frequency range of 10-1 Hz–106 Hz. The measured electrical conductivity along the ⊥ [001] axis direction decreases with increasing pressure, and the activation energy and activation volume of charge carriers are determined to be 1.04 ± 0.06 e V and 2.51 ± 0.19 cm~3/mole, respectively. The electrical conductivity of K-feldspar is highly anisotropic, and its value along the⊥ [001] axis is approximately three times higher than that along the ⊥ [100] axis. At 2.0 GPa, the diffusion coefficient of ionic potassium is obtained from the electrical conductivity data using the Nernst–Einstein equation. The measured electrical conductivity and calculated diffusion coefficient of potassium suggest that the main conduction mechanism is of ionic conduction, therefore the dominant charge carrier is transferred between normal lattice potassium positions and adjacent interstitial sites along the thermally activated electric field. 展开更多
关键词 electrical conductivity and diffusion coefficient K-feldspar anisotropy conduction mechanism
下载PDF
Hydro-mechanical-electrical simulations of synthetic faults in two orthogonal directions with shear-induced anisotropy
10
作者 Kazuki Sawayama Takuya Ishibashi +1 位作者 Fei Jiang Takeshi Tsuji 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第11期4428-4439,共12页
Fluid flow in fractures controls subsurface heat and mass transport,which is essential for developing enhanced geothermal systems and radioactive waste disposal.Fracture permeability is controlled by fracture microstr... Fluid flow in fractures controls subsurface heat and mass transport,which is essential for developing enhanced geothermal systems and radioactive waste disposal.Fracture permeability is controlled by fracture microstructure(e.g.aperture,roughness,and tortuosity),but in situ values and their anisotropy have not yet been estimated.Recent advances in geophysical techniques allow the detection of changes in electrical conductivity due to changes in crustal stress and these techniques can be used to predict subsurface fluid flow.However,the paucity of data on fractured rocks hinders the quantitative interpretation of geophysical monitoring data in the field.Therefore,considering different shear displacements and chemical erosions,an investigation was conducted into the hydraulic-electric relationship as an elevated stress change in fractures.The simulation of fracture flows was achieved using the lattice Boltzmann method,while the electrical properties were calculated through the finite element method,based on synthetic faults incorporating elastic-plastic deformation.Numerical results show that the hydraulic and electrical properties depend on the rock's geometric properties(i.e.fracture length,roughness,and shear displacement).The permeability anisotropy in the direction parallel or perpendicular to the shear displacement is also notable in high stress conditions.Conversely,the permeability econductivity(i.e.,formation factor)relationship is unique under all conditions and follows a linear trend in logarithmic coordinates.However,both matrix porosity and fracture spacing alter this relationship.Both increase the slope of the linear trend,thereby changing the sensitivity of electrical observations to permeability changes. 展开更多
关键词 Fracture flow Permeability electrical conductivity Lattice Boltzmann method ANISOTROPY Chemical erosion Enhanced geothermal system
下载PDF
Extrusion 3D printing of carbon nanotube-assembled carbon aerogel nanocomposites with high electrical conductivity
11
作者 Lukai Wang Jing Men +4 位作者 Junzong Feng Yonggang Jiang Liangjun Li Yijie Hu Jian Feng 《Nano Materials Science》 EI CAS CSCD 2024年第3期312-319,共8页
Carbon nanotubes(CNTs)with high aspect ratio and excellent electrical conduction offer huge functional improvements for current carbon aerogels.However,there remains a major challenge for achieving the on-demand shapi... Carbon nanotubes(CNTs)with high aspect ratio and excellent electrical conduction offer huge functional improvements for current carbon aerogels.However,there remains a major challenge for achieving the on-demand shaping of carbon aerogels with tailored micro-nano structural textures and geometric features.Herein,a facile extrusion 3D printing strategy has been proposed for fabricating CNT-assembled carbon(CNT/C)aerogel nanocomposites through the extrusion printing of pseudoplastic carbomer-based inks,in which the stable dispersion of CNT nanofibers has been achieved relying on the high viscosity of carbomer microgels.After extrusion printing,the chemical solidification through polymerizing RF sols enables 3D-printed aerogel nanocomposites to display high shape fidelity in macroscopic geometries.Benefiting from the micro-nano scale assembly of CNT nanofiber networks and carbon nanoparticle networks in composite phases,3D-printed CNT/C aerogels exhibit enhanced mechanical strength(fracture strength,0.79 MPa)and typical porous structure characteristics,including low density(0.220 g cm^(-3)),high surface area(298.4 m^(2)g^(-1)),and concentrated pore diameter distribution(~32.8nm).More importantly,CNT nanofibers provide an efficient electron transport pathway,imparting 3D-printed CNT/C aerogel composites with a high electrical conductivity of 1.49 S cm^(-1).Our work would offer feasible guidelines for the design and fabrication of shape-dominated functional materials by additive manufacturing. 展开更多
关键词 Carbon aerogel Extrusion 3D printing Carbon nanotube electrical conductivity RHEOLOGY
下载PDF
GLOBAL UNIQUE SOLUTIONS FOR THE INCOMPRESSIBLE MHD EQUATIONS WITH VARIABLE DENSITY AND ELECTRICAL CONDUCTIVITY
12
作者 Xueli KE 《Acta Mathematica Scientia》 SCIE CSCD 2024年第5期1747-1765,共19页
We study the global unique solutions to the 2-D inhomogeneous incompressible MHD equations,with the initial data(u0,B0)being located in the critical Besov space■and the initial densityρ0 being close to a positive co... We study the global unique solutions to the 2-D inhomogeneous incompressible MHD equations,with the initial data(u0,B0)being located in the critical Besov space■and the initial densityρ0 being close to a positive constant.By using weighted global estimates,maximal regularity estimates in the Lorentz space for the Stokes system,and the Lagrangian approach,we show that the 2-D MHD equations have a unique global solution. 展开更多
关键词 inhomogeneous MHD equations electrical conductivity global unique solutions
下载PDF
Fabrication of Graphene/Cu Composite by Chemical Vapor Deposition and Effects of Graphene Layers on Resultant Electrical Conductivity
13
作者 Xinyue Liu Yaling Huang +2 位作者 Yuyao Li Jie Liu Quanfang Chen 《Journal of Harbin Institute of Technology(New Series)》 CAS 2024年第1期16-25,共10页
Graphene(Gr)has unique properties including high electrical conductivity;Thus,graphene/copper(Gr/Cu)composites have attracted increasing attention to replace traditional Cu for electrical applications. However,the pro... Graphene(Gr)has unique properties including high electrical conductivity;Thus,graphene/copper(Gr/Cu)composites have attracted increasing attention to replace traditional Cu for electrical applications. However,the problem of how to control graphene to form desired Gr/Cu composite is not well solved. This paper aims at exploring the best parameters for preparing graphene with different layers on Cu foil by chemical vapor deposition(CVD)method and studying the effects of different layers graphene on Gr/Cu composite’s electrical conductivity. Graphene grown on single-sided and double-sided copper was prepared for Gr/Cu and Gr/Cu/Gr composites. The resultant electrical conductivity of Gr/Cu composites increased with decreasing graphene layers and increasing graphene volume fraction. The Gr/Cu/Gr composite with monolayer graphene owns volume fraction of less than 0.002%,producing the best electrical conductivity up to59.8 ×10^(6)S/m,equivalent to 104.5% IACS and 105.3% pure Cu foil. 展开更多
关键词 chemical vapor deposition(CVD) Gr/Cu Gr/Cu/Gr graphene layers graphene volume fraction electrical conductivity
下载PDF
Mechanical and Electrical Properties of Some Sn-Zn Based Lead-Free Quinary Alloys
14
作者 Shihab Uddin Md. Abdul Gafur +1 位作者 Suraya Sabrin Soshi Mohammad Obaidur Rahman 《Materials Sciences and Applications》 2024年第7期213-227,共15页
Although there are many lead-free soldering alloys on the market, none of them have ideal qualities. The researchers are combining binary alloys with a variety of additional materials to create the soldering alloys’ ... Although there are many lead-free soldering alloys on the market, none of them have ideal qualities. The researchers are combining binary alloys with a variety of additional materials to create the soldering alloys’ features. The eutectic Sn-9Zn alloy is among them. This paper investigated the mechanical and electrical properties of Sn-9Zn-x (Ag, Cu, Sb);{x = 0.2, 0.4, and 0.6} lead-free solder alloys. The mechanical properties such as elastic modulus, ultimate tensile strength (UTS), yield strength (YS), and ductility were examined at the strain rates in a range from 4.17 10−3 s−1 to 208.5 10−3 s−1 at room temperature. It is found that increasing the content of the alloying elements and strain rate increases the elastic modulus, ultimate tensile strength, and yield strength while the ductility decreases. The electrical conductivity of the alloys is found to be a little smaller than that of the Sn-9Zn eutectic alloy. 展开更多
关键词 Lead-Free Solder Strain Rate Ultimate Tensile Strength DUCTILITY electrical Conductivity
下载PDF
Effect of Zr and Sc on mechanical properties and electrical conductivities of Al wires 被引量:9
15
作者 钞润泽 管西花 +4 位作者 管仁国 铁镝 连超 王祥 张俭 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第10期3164-3169,共6页
In order to obtain the Al wires with good mechanical properties and high electrical conductivities, conductive wires of Al-0.16 Zr, Al-0.16 Sc, Al-0.12Sc-0.04Zr(mass fraction, %) and pure Al(99.996%) were produced... In order to obtain the Al wires with good mechanical properties and high electrical conductivities, conductive wires of Al-0.16 Zr, Al-0.16 Sc, Al-0.12Sc-0.04Zr(mass fraction, %) and pure Al(99.996%) were produced with the diameter of 9.5 mm by continuous rheo-extrusion technology, and the extruded materials were heat treated and analyzed. The results show that the separate additions of 0.16% Sc and 0.16% Zr to pure Al improve the ultimate tensile strength but reduce the electrical conductivity, and the similar trend is found in the Al-0.12Sc-0.04 Zr alloy. After the subsequent heat treatment, the wire with the optimum comprehensive properties is Al-0.12Sc-0.04 Zr alloy, of which the ultimate tensile strength and electrical conductivity reach 160 MPa and 64.03%(IACS), respectively. 展开更多
关键词 alloy composition Al wires mechanical properties electrical conductivity continuous rheo-extrusion
下载PDF
Electrical and mechanical properties of Cu-Cr-Zr alloy aged under imposed direct continuous current 被引量:6
16
作者 王志强 钟云波 +5 位作者 饶显君 汪超 王江 张增光 任维丽 任忠鸣 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第5期1106-1111,共6页
The Cu-Cr-Zr alloys were aged at different temperatures for different time with different current densities. The results show that both the electrical conductivity and hardness are greatly improved after being aged wi... The Cu-Cr-Zr alloys were aged at different temperatures for different time with different current densities. The results show that both the electrical conductivity and hardness are greatly improved after being aged with current at a proper temperature. The electrical conductivity increases approximately linearly with increasing current density while the hardness remains constant. The microstructure observation reveals that a much higher density of dislocations and nanosized Cr precipitates appear after the imposition of current, which contributes to the higher electrical conductivity and hardness. The mechanism is related with three factors: 1) Joule heating due to the current, 2) migration of mass electrons, 3) solute atoms, vacancies, and dislocations promoted by electron wind force. 展开更多
关键词 Cu-Cr-Zr alloy electrical conductivity HARDNESS current ageing PRECIPITATION
下载PDF
Enhanced thermal and electrical properties of poly (D,L-lactide)/ multi-walled carbon nanotubes composites by in-situ polymerization 被引量:5
17
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
下载PDF
Continuous changes in electrical conductivity of sodium aluminate solution in seeded precipitation 被引量:3
18
作者 刘桂华 李铮 +3 位作者 齐天贵 周秋生 彭志宏 李小斌 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第12期4160-4166,共7页
The mechanism of seeded precipitation of sodium aluminate solution was studied by measuring the seeded-precipitation rate and electrical conductivity online, as well as calculating the activity and fraction of ion pai... The mechanism of seeded precipitation of sodium aluminate solution was studied by measuring the seeded-precipitation rate and electrical conductivity online, as well as calculating the activity and fraction of ion pair. The results show that the electrical conductivity of sodium aluminate slurry linearly decreases with increasing aluminum hydroxide addition. Moreover, both the electrical conductivity of slurry and the difference in electrical conductivity between sodium aluminate solution and slurry remarkably decline in the first 60 min before gradually increasing in the preliminary 10 h and finally reaching almost the same level after 10 h. In low Na2 O concentration solution the activities of Na OH and Na Al(OH)4 in seeded precipitation are high, which can enlarge the difference in conductivity between slurry and solution. Additionally, more ion pairs exist in solution in preliminary seeded precipitation, and the adsorption of Na+Al(OH)4- on seed surface is likely to break the equilibrium of ion pair formation and to decrease the difference in conductivity in preliminary seeded precipitation. 展开更多
关键词 sodium aluminate solution seeded precipitation electrical conductivity activity coefficient ion pair
下载PDF
Electrical conductivity of NaF-AlF_3-CaF_2-Al_2O_3-ZrO_2 molten salts 被引量:3
19
作者 包莫日根高娃 王兆文 +3 位作者 高炳亮 石忠宁 胡宪伟 于江玉 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第12期3788-3792,共5页
The electrical conductivity of NaF-AlF3-CaF2-Al2O3-ZrO2 system was studied by a tube-type cell with fixed cell constant. The results show that the electrical conductivity of NaF-AlF3-3%Al2O3-3%CaF2-ZrO2 molten salt sy... The electrical conductivity of NaF-AlF3-CaF2-Al2O3-ZrO2 system was studied by a tube-type cell with fixed cell constant. The results show that the electrical conductivity of NaF-AlF3-3%Al2O3-3%CaF2-ZrO2 molten salt system decreases with increase of ZrO2 content in an interval of 0-5%. The increase of 1%ZrO2 results in a corresponding electrical conductivity decrease of 0.02 S/cm, and the equivalent conductivity increases with the increase of molar ratio of NaF to AlF3. When the temperature increases by 1 °C, the electrical conductivity increases by 0.004 S/cm. At last, the regression equations of electrical conductivity relative to temperature and ZrO2 are obtained by quadratic regression analysis. 展开更多
关键词 ZRO2 molten salt electrolysis electrical conductivity NAF ALF3 Al-Zr alloy
下载PDF
Mechanical properties,electrical conductivity and microstructure of CuCrZr alloys treated with thermal stretch process 被引量:3
20
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
下载PDF
上一页 1 2 27 下一页 到第
使用帮助 返回顶部