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“赝立方”微观结构助力设计新型热电化合物
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《传感器世界》 2014年第4期44-44,共1页
开发高性能热电转换材料、拓展热电转换技术的工业应用是目前热电科学与技术领域的首要任务。长期以来热电材料科学研究主要集中在高对称性立方结构材料。而在自然界中化合物主要以非立方结构为主,如何从众多的非立方结构化合物中筛选... 开发高性能热电转换材料、拓展热电转换技术的工业应用是目前热电科学与技术领域的首要任务。长期以来热电材料科学研究主要集中在高对称性立方结构材料。而在自然界中化合物主要以非立方结构为主,如何从众多的非立方结构化合物中筛选出新热电材料已成为热电材料研究的巨大挑战。 展开更多
关键词 热电化合物 立方结构 微观结构 设计 热电转换材料 热电转换技术 热电材料 科学与技术
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Nd_xCo_4Sb_(12)化合物的快速合成及其热电性能研究 被引量:3
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作者 张久兴 刘科高 +3 位作者 路清梅 张隆 周美玲 左铁镛 《中国稀土学报》 CAS CSCD 北大核心 2004年第3期341-344,共4页
采用机械合金化和放电等离子烧结 (MA SPS)技术成功合成了NdxCo4 Sb1 2 化合物热电材料。借助于先进的结构和性能表征手段 ,系统研究了NdxCo4 Sb1 2 化合物成相和热电性能。实验结果表明 ,NdxCo4 Sb1 2 化合物中稀土Nd的最佳添加量为x =... 采用机械合金化和放电等离子烧结 (MA SPS)技术成功合成了NdxCo4 Sb1 2 化合物热电材料。借助于先进的结构和性能表征手段 ,系统研究了NdxCo4 Sb1 2 化合物成相和热电性能。实验结果表明 ,NdxCo4 Sb1 2 化合物中稀土Nd的最佳添加量为x =1.0。Nd1 .0 Co4 Sb1 2 化合物具有较高的热电性能 ,其中在 40 0℃时具有最大ZT值 0 .2 65。 展开更多
关键词 热电化合物 ND 机械合金化 放电等离子烧结 稀土
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Yb掺杂对热电化合物Ca_(3-x)Yb_xCo_4O_(9+δ)电性能的影响 被引量:1
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作者 褚颖 王忠 蒋利军 《稀有金属》 EI CAS CSCD 北大核心 2010年第2期227-230,共4页
采用溶胶凝胶法合成Ca3-xYbxCo4O9+δ(x=0,0.15,0.30,0.45)化合物粉体,以粉体为原料结合放电等离子烧结(SparkPlasmaSinte-ring,SPS)制备出致密的块体材料。研究了Yb掺杂对热电化合物电传输特性的影响。结果表明:在300~850K温度范围内... 采用溶胶凝胶法合成Ca3-xYbxCo4O9+δ(x=0,0.15,0.30,0.45)化合物粉体,以粉体为原料结合放电等离子烧结(SparkPlasmaSinte-ring,SPS)制备出致密的块体材料。研究了Yb掺杂对热电化合物电传输特性的影响。结果表明:在300~850K温度范围内,每个样品的See-beck系数又随着温度的升高而单调增大,而Yb取代Ca可使材料的电阻率(ρ)和Seebeck系数同时增加,这是因为三价的Yb3+取代二价的Ca2+将使化合物的载流子浓度降低,当x=0.30时,材料的功率因子最佳,850K时达到0.32×10-3W.K-.2m-1。 展开更多
关键词 Yb掺杂 热电化合物 SEEBECK系数
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共溅镀法制造热电化合物Mg2Sn薄膜
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《金属功能材料》 CAS 2012年第2期30-30,共1页
法国亚原子物理学与宇宙学实验室H.LeQuoc等人,在室温下用等离子共溅镀法在硅基板和玻璃基板上沉积出掺Ag的MgzSn薄膜。
关键词 热电化合物 薄膜 溅镀 制造 原子物理学 玻璃基板 实验室 宇宙学
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用固相反应合成Mg_2Si_(1-x)Ge_x热电固溶体 被引量:4
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作者 姜洪义 张联盟 《硅酸盐通报》 CAS CSCD 2002年第2期12-15,共4页
利用二次固相反应合成的方法 ,在低温下首次合成了Mg2 Si1-xGex 系连续固溶体 ;所制得的产品呈单相特征 ,不含任何氧化物或碳化物 ,且颗粒粒径大幅度细化。对产物相组成以及固相反应过程中热量的变化 ,掺Ge对Mg2 Si1-xGex
关键词 固相反应 合成 Mg2Si1-xGex 热电固溶体 晶胞参数 热电化合物 热电半导体
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放电等离子烧结对Ba_8Si_(30)Ga_(16)晶体结构和热电性能的影响
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作者 栗峰 刘丽华 +2 位作者 邱红梅 曹国辉 李阳 《材料导报》 EI CAS CSCD 北大核心 2013年第24期12-17,共6页
采用电弧炉熔炼、球磨结合放电等离子烧结(SPS)的方法合成了系列第I类笼状化合物Ba8Si30Ga16,研究了样品的晶体结构和热电性能随SPS烧结温度的变化规律。研究结果表明,随着SPS烧结温度由800℃升高到1000℃,Ba8Si30Ga16样品的晶格常数由1... 采用电弧炉熔炼、球磨结合放电等离子烧结(SPS)的方法合成了系列第I类笼状化合物Ba8Si30Ga16,研究了样品的晶体结构和热电性能随SPS烧结温度的变化规律。研究结果表明,随着SPS烧结温度由800℃升高到1000℃,Ba8Si30Ga16样品的晶格常数由10.5435(4)减小到10.5274(2),Ba8Si30Ga16笼上Ga含量的降低可能是导致晶格常数减小的主要原因。样品的Seebeck系数、电导率、热导率、热电优值ZT均受SPS烧结温度的影响。其中,800℃SPS烧结样品的ZT值最大,这与其较低的热导率有关。 展开更多
关键词 第1类笼状化合物晶格常数热电性能
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Formation mechanisms of Ni-Al intermetallics during heat treatment of Ni coating on 6061 Al substrate 被引量:8
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作者 Mohsen ADABI Ahmad Ali AMADEH 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第12期3959-3966,共8页
The formation mechanisms and growth kinetics of Al3 Ni and Al3Ni2 in Ni-Al diffusion couple prepared by electrodeposition of Ni on Al substrate were investigated. The nickel coating with 20 μm thickness was applied o... The formation mechanisms and growth kinetics of Al3 Ni and Al3Ni2 in Ni-Al diffusion couple prepared by electrodeposition of Ni on Al substrate were investigated. The nickel coating with 20 μm thickness was applied on 6061 aluminum alloy by direct current electroplating. The samples were then heat-treated for different durations at 450, 500 and 550 °C under argon atmosphere. The intermetallic phases were identified by means of scanning electron microscopy(SEM), energy dispersive spectrometry(EDS) and X-ray diffraction(XRD). The results showed that the formation of intermetallic phases consisted of two important steps. The first step was the lateral growth of intermetallic phase from separate sites, resulting in the formation of a continuous layer. The second step was the growth of the continuous intermetallic layer in the direction perpendicular to the interface. However, excessive increase in thickness of intermetallic phases led to the detachment of reaction products, i.e., Al3 Ni and Al3Ni2, from the substrate. It was also observed that aluminum was the dominant diffusing element during Al3 Ni growth, while nickel diffusion was dominant during Al3Ni2 growth. The growth kinetics of both Al3 Ni and Al3Ni2 phases obeyed a parabolic law. 展开更多
关键词 Ni-Al intermetallics ELECTRODEPOSITION heat treatment formation mechanism growth kinetics
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Synthesis and characterization of Na0.44MnO2 nanorods/graphene composite as cathode materials for sodium-ion batteries 被引量:5
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作者 ZHANG Yue OUYANG Yan +4 位作者 LIU Li XIA Jing NIE Su LIU Wen WANG Xian-you 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第6期1510-1520,共11页
Na0.44MnO2 nanorods have been prepared by a hydrothermal method.The experimental parameters have been systematically investigated and optimized.The results show that Na0.44MnO2 nanorods obtained via the hydrothermal t... Na0.44MnO2 nanorods have been prepared by a hydrothermal method.The experimental parameters have been systematically investigated and optimized.The results show that Na0.44MnO2 nanorods obtained via the hydrothermal treatment at 200℃for 16 h show the best electrochemical properties,which deliver the high initial discharge capacity of 110.7 mA·h/g at 50 mA/g in potential window 2.0-4.0 V.To further improve their electrochemical properties,a ball milling process with graphene has been carried out to obtain Na0.44MnO2/graphene composite.The initial discharge capacity of Na0.44MnO2/graphene composite is 106.9 mA·h/g at a current density of 50 mA/g.After 100 cycles,the residual discharge capacity is 91.8 mA·h/g and the capacity retention rate is 85.9%,which is much higher than that of pristine Na0.44MnO2 nanorods(74.7%)at the same condition.What is more,when the current density reaches 500 and 1000 mA/g,the corresponding discharge capacities of Na0.44MnO2/graphene composite are about 89 and 78 mA·h/g,respectively,indicating outstanding rate capability. 展开更多
关键词 manganese-based compounds hydrothermal method sodium-ion batteries composite materials
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Structure and electrochemical properties of LiCoO_2 synthesized by microwave heating 被引量:1
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作者 胡国荣 廖刚 +3 位作者 彭忠东 肖劲 张新龙 禹筱元 《Journal of Central South University of Technology》 EI 2004年第3期261-264,共4页
Microwave synthesis method was applied to the fast preparation of LiCoO2. The structure of the synthesized oxides was analyzed by using X-ray diffraction. Only single-phase LiCoO2 was obtained. Electrochemical behavio... Microwave synthesis method was applied to the fast preparation of LiCoO2. The structure of the synthesized oxides was analyzed by using X-ray diffraction. Only single-phase LiCoO2 was obtained. Electrochemical behaviors of LiCoO2 were investigated by charge-discharge cycling properties in the voltage range of 3.004.35 V((vs Li).) The results show that the prepared LiCoO2 powders calcinated at 900 ℃ for 120 min exhibit an initial charge and discharge capacity of 168 and 162 mA·h·g-1 at 0.1C current rate, respectively, as compared to 159 and 154 (mA·h·g-1) of LiCoO2 synthesized by conventional means. In addition, more than 95% of the capacity is retained (even) after 10 cycles. But with the increase of calcinating time, its electrochemical properties deteriorate. Compared with the conventional method, the microwave heating method is simple, fast, and with high energy efficiency. 展开更多
关键词 microwave synthesis method Li-ion battery cathode material LiCoO_2
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Electrical resistance stability of high content carbon fiber reinforced cement composite 被引量:1
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作者 杨再富 《Journal of Chongqing University》 CAS 2005年第1期19-22,共4页
The influences of curing time, the content of free evaporable water in cement paste, environmental temperature, and alternative heating and cooling on the electrical resistance of high content carbon fiber reinforced ... The influences of curing time, the content of free evaporable water in cement paste, environmental temperature, and alternative heating and cooling on the electrical resistance of high content carbon fiber reinforced cement (CFRC) paste are studied by experiments with specimens of Portland cement 42.5 with 10 mm PAN-based carbon fiber and methylcellulose. Experimental results indicate that the electrical resistance of CFRC increases relatively by 24% within a hydration time of 90 d and almost keeps constant after 14 d, changes hardly with the mass loss of free evaporable water in the concrete dried at 50 °C, increases relatively by 4% when ambient temperature decreases from 15 °C to ?20 °C, and decreases relatively by 13% with temperature increasing by 88 °C. It is suggested that the electric resistance of the CFRC is stable, which is testified by the stable power output obtained by electrifying the CFRC slab with a given voltage. This implies that such kind of high content carbon fiber reinforced cement composite is potentially a desirable electrothermal material for airfield runways and road surfaces deicing. 展开更多
关键词 carbon fiber reinforced cement electrical resistance STABILITY ELECTROTHERMAL
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Formation and wear behaviors of in-situ Al3Ti/Al composites using aluminum and titanium fibers under electromagnetic induction heating 被引量:1
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作者 MA Jun NIU Li-bin +2 位作者 WU Hong GAO Chong AN Yu-jiao 《Journal of Central South University》 SCIE EI CAS CSCD 2020年第12期3594-3602,共9页
Under various electromagnetic induction heating powers,different Al3Ti/Al composites were fabricated by in-situ synthesis method from aluminum and titanium fibers.Microstructures and particles distribution of the comp... Under various electromagnetic induction heating powers,different Al3Ti/Al composites were fabricated by in-situ synthesis method from aluminum and titanium fibers.Microstructures and particles distribution of the composites were examined by XRD,SEM and EDS.The results show that no other intermetallic compounds beside Al3Ti can be in-situ synthesized.Around the titanium fibers,the reaction zones and diffusion zones can be obviously found.Due to the stirring of the electromagnetic function,the formation of the micro-cracks inside the reaction zone was conducive to the peeling off of the Al3Ti particles,and ensures the continuous reaction between liquid aluminum and titanium fibers,as well as the diffusion of Al3Ti particles.At the same time,there were secondary splits of Al3Ti particles located in diffusion zones.Two-body abrasion test shows that with the increase of induction heating power,the wear rates of the composites reduced and the number of grooves decreased. 展开更多
关键词 in-situ synthesis induction heating Al3Ti intermetallic particle distribution wear behaviors
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Heat and Radiation Generation during Hydrogenation of CH Compound
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作者 T. Mizuno 《Journal of Environmental Science and Engineering》 2011年第8期1017-1025,共9页
Securing new sources of energy has become a major concern, because fossil fuels are expected to be depleted within several decades. In some of the major wars of the 20th century, control of oil was either a proximate ... Securing new sources of energy has become a major concern, because fossil fuels are expected to be depleted within several decades. In some of the major wars of the 20th century, control of oil was either a proximate cause or a decisive factor in the outcome. Especially in Japan and Germany, a great deal of research was devoted to making liquid fuels from coal. In one such experiment, a large amount of excess heat was observed. The present study was devoted to replicating and controlling that excess heat effect. The reactant is phenanthrene, a heavy oil fraction, which is subjected to high pressure and high heat in the presence of a metal catalyst. This results in the production of excess heat and strong penetrating electromagnetic radiation. After the reaction, an analysis of residual gas reveals a variety of hydrocarbons, but it seems unlikely that these products can explain the excess heat. Most of them form endothermically, and furthermore heat production reached 60 W. Overall heat production exceeded any conceivable chemical reaction by two orders of magnitude. 展开更多
关键词 Heat generation HYDROGEN carbon catalyzer
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Two Anderson-based supramolecular compounds modified by 4,4'-dipyridy synthesized in one-pot
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作者 LI Tingting TIAN Aixiang YING Jun 《分子科学学报》 CAS 2024年第2期160-166,共7页
Using symmetrical rigid organic ligand 4,4'-dipyridy(4,4'-bipy),two new Anderson-based supramolecular compounds,namely,[H_(2)(4,4'-bipy)]_(3)·(TeMo_(6)O_(24))·(H_(2)Mo_(6)O_(19))(1)and{Cu_(2)[H(4... Using symmetrical rigid organic ligand 4,4'-dipyridy(4,4'-bipy),two new Anderson-based supramolecular compounds,namely,[H_(2)(4,4'-bipy)]_(3)·(TeMo_(6)O_(24))·(H_(2)Mo_(6)O_(19))(1)and{Cu_(2)[H(4,4'-bipy)]_(2)(H_(2)O)_(6)(TeMo_(6)O_(24))}·4H_(2)O(2),were synthesized in one-pot under hydrothermal conditions.The compounds 1 and 2 have been tested by IR spectra,elemental analyses and single-crystal X-ray diffraction.Compound 1 contains one discrete Anderson anion,one Lindqvist anion and three 4,4'-bipy organic ligands.The anions and 4,4'-bipy alternate with each other by hydrogen bonding,building a supramolecular 1D chain.Adjacent 1D chains are interlinked through hydrogen bonding interactions to further connect a supramolecular 2D layer.Compounds containing both Anderson and Lindqvist polyanions are not common in the crystal structure of POMs.Compound 2 contains one Anderson anion and two metal-organic subunits{Cu_(2)[H(4,4'-bipy)]_(2)(H_(2)O)_(6)}^(6+)as modifiers.The Anderson anions and{Cu_(2)[H(4,4'-bipy)]_(2)(H_(2)O)_(6)}^(6+)subunits are organized into alternating through hydrogen bonding interactions to construct a supramolecular 1D chain.Additionally,the electrochemical properties of compounds 1 and 2 as well as photocatalytic properties are investigated.Results show that compounds 1 and 2 have photocatalytic activity,which can photocatalyze the degradation of organic dyes MB and AF.Also,compounds 1 and 2 have good electrochemical properties for amperometric detection of NO2-and Cr(Ⅵ).Furthermore,Compound 2 can be used as materials of supercapacitor. 展开更多
关键词 Anderson POM hydrothermal syntheses supramolecular structure ELECTROCHEMISTRY PHOTOCATALYSIS
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Power generation and heat sink improvement characteristics of recooling cycle for thermal cracked hydrocarbon fueled scramjet 被引量:7
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作者 BAO Wen QIN Jiang +2 位作者 ZHOU WeiXing ZHANG Duo YU DaRen 《Science China(Technological Sciences)》 SCIE EI CAS 2011年第4期955-963,共9页
In order to further investigate how much fuel heat sink could be increased and how much power generation could be obtained by using recooling cycle for a regeneratively cooled scramjet,the energy conversion from heat ... In order to further investigate how much fuel heat sink could be increased and how much power generation could be obtained by using recooling cycle for a regeneratively cooled scramjet,the energy conversion from heat to electricity and the fuel heat sink increase in recooling cycle are experimentally investigated for fuel conversion rate and components of gas cracked fuel products at different fuel temperatures.The results indicate that the total fuel heat sink(i.e.,physical+chemical+recooling) of a recooling cycle is obviously higher than the heat sink of fuel itself,and the maximum heat sink increment is as high as 0.4 MJ/kg throughout the recooling cycle.Furthermore,the cracked fuel mixture has a significant capacity of doing work.The thermodynamic power generation scheme,which adopts the cracked fuel gas mixture as the working fluid,is a potential power generation cycle,and the maximum specific power generation is about 500 kW/kg.Turbine-pump scheme using cracked fuel gas mixture is also a potential fuel feeding cycle. 展开更多
关键词 recooling cycle SCRAMJET heat sink power generation thermal cracking
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Copper chalcogenide thermoelectric materials 被引量:5
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作者 Tian-Ran Wei Yuting Qin +6 位作者 Tingting Deng Qingfeng Song Binbin Jiang Ruiheng Liu Pengfei Qiu Xun Shi Lidong Chen 《Science China Materials》 SCIE EI CSCD 2019年第1期8-24,共17页
Cu-based chalcogenides have received increasing attention as promising thermoelectric materials due to their high efficiency,tunable transport properties,high elemental abundance and low toxicity.In this review,we sum... Cu-based chalcogenides have received increasing attention as promising thermoelectric materials due to their high efficiency,tunable transport properties,high elemental abundance and low toxicity.In this review,we summarize the recent research progress on this large family compounds covering diamond-like chalcogenides and liquid-like Cu2X (X=S,Se,Te)binary compounds as well as their multinary derivatives.These materials have the general features of two sublattices to decouple electron and phonon transport properties.On the one hand,the complex crystal structure and the disordered or even liquid-like sublattice bring about an intrinsically low lattice thermal conductivity.On the other hand, the rigid sublattice constitutes the charge-transport network, maintaining a decent electrical performance.For specific material systems,we demonstrate their unique structural features and outline the structure-performance correlation. Various design strategies including doping,alloying,band engineering and nanostructure architecture,covering nearly all the material scale,are also presented.Finally,the potential of the application of Cu-based chalcogenides as high-performance thermoelectric materials is briefly discussed from material design to device development. 展开更多
关键词 THERMOELECTRIC Cu-based chalcogenides SUBLATTICE transport properties
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Structural,electronic,and thermoelectric properties of La_2CuBiS_5 被引量:1
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作者 杨癸 姚艳红 马东伟 《Science China Materials》 SCIE EI CSCD 2017年第2期151-158,共8页
The basic physical properties of La_2CuBiS_5 are studied by the first-principle calculations and the semiclassical Boltzmann theory.Charge density difference calculations show that electrons accumulate between Bi-S at... The basic physical properties of La_2CuBiS_5 are studied by the first-principle calculations and the semiclassical Boltzmann theory.Charge density difference calculations show that electrons accumulate between Bi-S atoms,indicating considerable covalent bonding of Bi and S atoms.A similar charge density difference indicates that the Cu-S bonds also exhibit covalent character.The calculated minimum thermal conductivity of La_2CuBiS_5 is low,which is conducive to its use as a thermoelectric material.Owing to a bipolar effect,induced by thermal excitation,the material's Seebeck coefficient decreases sharply at T = 800 K.For the n-type and p-type doping conditions,the largest values of S^2σ/τ were calculated as-1.71×10^(11) and 1.837×10^(11) W K^(-2)ms^(-1),respectively.The combination of a large dispersion and a high band degeneracy along the Γ-Y direction in the band structure simultaneously induces the highest S_y value and a high σ/τ_y value.Thus,the thermoelectric performance of La_2CuBiS_5 is anisotropic and most favorable along the y direction. 展开更多
关键词 chemical bond electronic structure thermoelectric properties
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