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含锡AB_5型非化学计量贮氢合金Ⅰ.合金的结构 被引量:8
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作者 王志兴 李新海 +3 位作者 陈启元 郭炳昆 彭文杰 郭华军 《中国稀土学报》 CAS CSCD 北大核心 2000年第2期128-130,共3页
采用X射线衍射法研究了LaNi5 .1 5 ,La(NiSn) 5 .1 4 ,La(NiSnCo) 5 .1 2 ,La(NiSnMn) 5 .1 2 ,La(NiSnCoMnAl) 5 .1 0 5种AB5 型非化学计量贮氢合金的结构。发现主物相中并未产生第二物相 ,AB5 型贮氢合金中B原子数发生正偏移时 ,晶胞... 采用X射线衍射法研究了LaNi5 .1 5 ,La(NiSn) 5 .1 4 ,La(NiSnCo) 5 .1 2 ,La(NiSnMn) 5 .1 2 ,La(NiSnCoMnAl) 5 .1 0 5种AB5 型非化学计量贮氢合金的结构。发现主物相中并未产生第二物相 ,AB5 型贮氢合金中B原子数发生正偏移时 ,晶胞体积减小 ,当B侧含有取代元素时 ,这种变化更加明显。对于非化学计量贮氢合金而言 ,少量Sn取代Ni后 ,晶胞体积大大提高。Mn ,Co和Al的加入也会影响晶胞常数。Sn ,Co ,Mn ,Al均会降低贮氢合金放氢平台压力。 展开更多
关键词 稀土 贮氢合金 非化学计量 电池 结构 AB5型合金
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钛掺杂的非化学计量LiFePO_4的合成与电化学性能研究(英文) 被引量:11
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作者 孙玉恒 刘东强 +1 位作者 吁霁 刘兴泉 《无机化学学报》 SCIE CAS CSCD 北大核心 2006年第9期1711-1714,共4页
Ti-doped nonstoichiometric LiFePO4, i.e. Li0.95Fe0.95Ti0.05PO4 was synthesized by solid-state reaction method. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscope (SEM... Ti-doped nonstoichiometric LiFePO4, i.e. Li0.95Fe0.95Ti0.05PO4 was synthesized by solid-state reaction method. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscope (SEM) and electrochemical charge and discharge tests were used to characterize the as-prepared sample. The results indicate that Li0.95Fe0.95Ti0.05PO4 used as the cathode material for lithium-ion battery exhibits improved cyclic stability and rate capability than those of undoped LiFePO4. 150 mAh·g-1 of discharge capacity was achieved at 0.1 C (17 mA ·g-1) at room temperature. 展开更多
关键词 LIFEPO4 电化学性能 钛掺杂 非化学计量
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含锡AB_5型非化学计量贮氢合金Ⅱ.电化学性能 被引量:6
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作者 王志兴 李新海 +3 位作者 陈启元 郭炳昆 郭华军 彭文杰 《中国稀土学报》 CAS CSCD 北大核心 2000年第3期225-228,共4页
研究了几种AB5非化学计量贮氢合金的电化学性能 ,及在低电流密度与高电流密度放电下取代元素对放电比容量、活化性能及循环寿命的影响。Sn ,Co,Mn的加入有利于提高合金的电化学贮氢容量 ,La(NiSn) 5.14 ,La(NiSnCo) 5.12 和La(NiSnMn) 5... 研究了几种AB5非化学计量贮氢合金的电化学性能 ,及在低电流密度与高电流密度放电下取代元素对放电比容量、活化性能及循环寿命的影响。Sn ,Co,Mn的加入有利于提高合金的电化学贮氢容量 ,La(NiSn) 5.14 ,La(NiSnCo) 5.12 和La(NiSnMn) 5.12 具有相同的电化学贮氢容量与活化特性。尽管La(NiSn) 5.14 大电流放电性能优于La(NiSnCo) 5.12 和La(NiSnMn) 5.12 ,但其寿命短。Mn ,Co和Al可大大提高合金的使用寿命。La(NiSnCo) 5.12 被认为是一种理想的贮氢合金。 展开更多
关键词 稀土 贮氢合金 非化学计量 电化学性能 蓄电池
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Fabricationofcerium-dopednonstoichiometric(Ce,Lu,Gd)_(3+δ)(Ga,Al)_(5–δ)O_(12) transparent ceramics 被引量:4
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作者 陈先强 秦海明 +4 位作者 张烨 罗朝华 刘永福 蒋俊 江浩川 《Journal of Rare Earths》 SCIE EI CAS CSCD 2015年第8期863-866,共4页
Cerium-doped nonstoichiometric (Ce,Lu, Gd)3+δ,(Ga,A1)5-δO12 (LuGGAG) transparent garnet ceramic samples were fabricated via a solid state reaction method in this study. The ceramics were prepared via oxygen s... Cerium-doped nonstoichiometric (Ce,Lu, Gd)3+δ,(Ga,A1)5-δO12 (LuGGAG) transparent garnet ceramic samples were fabricated via a solid state reaction method in this study. The ceramics were prepared via oxygen sintering followed by hot isostatic pressing (HIP). The phase and microstructure of the samples were analyzed by X-ray diffraction and scanning electron microscopy (SEM), respectively. The excitation, emission and transmission spectra were also measured. The total optical transmittance of the annealed LuGGAG ceramics with thickness of 3 mm reached 47% at the emission wavelength of 555 nm. The decay time was about 60 ns. Compact microstructure of polycrystalline grains with scale around 5 μm were gained according to scanning electron microscopy characterization. The successful preparation of the bulk ceramic material and implementation of the combined oxygen sintering-hot isostatie pressing treatment process provided an important method for the exploration of nonstoichiometrie scintillator material. 展开更多
关键词 transparent ceramic nonstoichiometric microstructure optical properties rare earths
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UltrahighQ Sr_(1+x)Y_(2)O_(4+x)(x=0-0.04)microwave dielectric ceramics for temperature-stable millimeter-wave dielectric resonator antennas
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作者 Guoqiang He Yu Jiang +9 位作者 Kaixin Song Yanjun Liu Yuan Nie Wenjie Zhang Ziqi Zhao Yinghan He Xinyue Ma Xiuli Chen Xu Li Huanfu Zhou 《Journal of Advanced Ceramics》 SCIE EI CAS CSCD 2024年第2期155-165,共11页
Microwave dielectric ceramics should be improved to advance mobile communication technologies further.In this study,we prepared Sr_(1+x)Y_(2)O_(4+x)(x=0-0.04)ceramics with nonstoichiometric Sr^(2+)ratios based on our ... Microwave dielectric ceramics should be improved to advance mobile communication technologies further.In this study,we prepared Sr_(1+x)Y_(2)O_(4+x)(x=0-0.04)ceramics with nonstoichiometric Sr^(2+)ratios based on our previously reported SrY_(2)O_(4) microwave dielectric ceramic,which has a low dielectric constant and an ultrahigh quality factor(Q value).The ceramic exhibited a 33.6% higher Q-by-frequency(Q×f)value(Q≈12,500)at x=0.02 than SrY_(2)O_(4).All Sr_(1+x)Y_(2)O_(4+x)(x=0-0.04)ceramics exhibited pure phase structures,although variations in crystal-plane spacings were observed.The ceramics are mainly composed of Sr-O,Y1-O,and Y_(2)-O octahedra,with the temperature coefficient of the resonant frequency(τ_(f))of the ceramic increasing with Y_(2)-O octahedral distortion.The ceramic comprises uniform grains with a homogeneous elemental distribution,clear grain boundaries,and no obvious cavities at x=0.02.The Sr_(1+x)Y_(2)O_(4+x)(x=0-0.04)ceramics exhibited good microwave dielectric properties,with optimal performance observed at x=0.02(dielectric constant(εr)=15.41,Q×f=112,375 GHz,and τ_(f)=-17.44 ppm/℃).The τ_(f) value was reduced to meet the temperaturestability requirements of 5G/6G communication systems by adding CaTiO_(3),with Sr_(1.02)Y_(2)O_(4.02)+2wt% CaTiO_(3) exhibiting ε_(r)=16.14,Q×f=51,004 GHz,andτf=0 ppm/℃.A dielectric resonator antenna prepared using Sr_(1.02)Y_(2)O_(4.02)+2wt%CaTiO_(3) exhibited a central frequency of 26.6 GHz,with a corresponding gain and efficiency of 3.66 dBi and 83.14%,respectively.Consequently,Sr_(1.02)Y_(2)O_(4).02-based dielectric resonator antennas are suitable for use in 5G millimeter-wave band(24.5-27.5 GHz)applications. 展开更多
关键词 millimeter wave microwave dielectric ceramics dielectric resonator antenna nonstoichiometric ratio
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混合稀土贮氢合金(Ml)_x(Ni_(3.8)Co_(0.75)Mn_(0.4)Ti_(0.05))相结构与性能的研究 被引量:3
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作者 任可 雷永泉 +2 位作者 陈立新 张庆安 王启东 《稀有金属材料与工程》 SCIE EI CAS CSCD 北大核心 2000年第4期235-238,共4页
对 (Ml) x(Ni3.8Co0 .75Mn Ti0 .0 5)合金 (x =0 .90~ 1 .1 0 )的相结构 ,热力学性能及合金电极的充放电性能进行了研究。结果表明 :在 x <1 .0 0的成分范围内 ,合金保持单一的 La Ni5相 ;当 x≥ 1 .0 0时 ,合金中析出多种第二相 ,... 对 (Ml) x(Ni3.8Co0 .75Mn Ti0 .0 5)合金 (x =0 .90~ 1 .1 0 )的相结构 ,热力学性能及合金电极的充放电性能进行了研究。结果表明 :在 x <1 .0 0的成分范围内 ,合金保持单一的 La Ni5相 ;当 x≥ 1 .0 0时 ,合金中析出多种第二相 ,且总量随 x的增加而增多。随着 x的增加 ,合金的晶胞体积及氢化物生成焓 (-ΔH )增大 ,吸放氢平台压力降低 ,宽度增加。合金的最大放电容量在 x =1 .0 0 时达到最大值 (30 7.7m Ah/g)。x <1 .0 0 合金的循环稳定性优于 x≥ 1 .0 0 合金。 展开更多
关键词 混合稀土 贮氢合金 贮氢性能 相结构
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Homogenous coating of Li^(+)conductive Li_(5)AlO_(4)on single-crystalline nonstoichiometric Li_(1.04)Ni_(0.92)Al_(0.04)O_(2)for rechargeable lithium-ion batteries
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作者 Guoyu Ding Shizhou Wang +11 位作者 Jinhan Li Ziyan Wu Jiayu Chen Jiayong Du Xinhui Huang Kuiming Liu Yudong Zhang Zhonghan Wu Yiyang Peng Qiancheng Zhao Meng Yu Fangyi Cheng 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第8期651-659,I0014,共10页
Cobalt-free,nickel-rich LiNi_(1-x)Al_(x)O_(2)(x≤0.1)is an attractive cathode material because of high energy density and low cost but suffers from severe structural degradation and poor rate performance.In this study... Cobalt-free,nickel-rich LiNi_(1-x)Al_(x)O_(2)(x≤0.1)is an attractive cathode material because of high energy density and low cost but suffers from severe structural degradation and poor rate performance.In this study,we propose a molten salt-assisted synthesis in combination with a Li-refeeding induced aluminum segregation strategy to prepare Li_(5)AlO_(4)-coated single-crystalline slightly Li-rich Li_(1.04)Ni_(0.92)Al_(0.04)O_(2).The symbiotic formation of Li_(5)AlO_(4)from reaction between molten lithium hydroxide and doped aluminum in the bulk ensures a high lattice matching between the Ni-rich oxide and the homogenous conductive Li_(5)AlO_(4)that permits high Li^(+)conductivity.Benefiting from mitigated undesirable side reactions and phase evolution,the Li_(5)AlO_(4)-coated single-crystalline Li_(1.04)Ni_(0.92)Al_(0.04)O_(2)delivers a high specific capacity of220.2 mA h g^(-1)at 0.1 C and considerable rate capability(182.5 mA h g^(-1)at 10 C).Besides,superior capacity retention of 90.8%is obtained at 1/3 C after 100 cycles in a 498.1 mA h pouch full cell.Furthermore,the particulate morphology of Li_(1.04)Ni_(0.92)Al_(0.04)O_(2)remains intact after cycling at a cutoff voltage of 4.3 V,whereas slightly Li-deficient Li_(0.98)Ni_(0.97)Al_(0.05)O_(2)features intragranular cracks and irreversible lattice distortion.The results highlight the value of molten salt-assisted synthesis and Li-refeeding induced elemental segregation strategy to upgrade Ni-based layered oxide cathode materials for advanced Li-ion batteries. 展开更多
关键词 Aluminum segregation Surface coating nonstoichiometric oxides Molten synthesis Cathode materials
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非化学计量化合物与过渡族金属碳化物、氮化物研究进展 被引量:5
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作者 颜练武 吴恩熙 黄伯云 《硬质合金》 CAS 北大核心 2008年第4期261-263,共3页
本文介绍了非化学计量化合物的研究历史及研究内容,介绍了过渡族金属碳化物、氮化物的物理特性及应用领域。
关键词 非化学计量 过渡族 碳化物 氮化物
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Novel cemented carbide produced with TiN_(0.3) and high-entropy alloys 被引量:2
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作者 Zhan-Wen He Ming-Zhi Wang +2 位作者 Xue-Long Hao Qin Zou Yu-Cheng Zhao 《Rare Metals》 SCIE EI CAS CSCD 2017年第6期494-500,共7页
High-entropy alloys are suitable for use as a binder for cemented carbides duo to outstanding mechanical, oxidation and wear behavior. Therefore, high-entropy alloy was selected to replace Co and Ni metal bond in this... High-entropy alloys are suitable for use as a binder for cemented carbides duo to outstanding mechanical, oxidation and wear behavior. Therefore, high-entropy alloy was selected to replace Co and Ni metal bond in this study. The results of X-ray diffraction analysis show that CoCrNiCuMn high-entropy alloy is stabilized in the cemented carbide system. Scanning electron microscope(SEM) fractural morphologies of the cemented carbides added with CoCrNiCuMn show that CoCrNiCuMn distributes in grain boundaries, and the grains are bound tightly together. Furthermore, SEM fractural morphologies of the cemented carbides with 5 wt%, 7 wt%, and 10 wt% CoCrNiCuMn show that CoCrNiCuMn slows the growth of grains, which effectively binders the grains, prevents the generation and propagation of cracks, and finally, greatly improves the toughness of the cemented carbides.According to the results observed in the cemented carbides containing different amounts of CoCrNiCuMn, the hardness level gradually increases with the amount of CoCrNiCuMn; however, a reverse trend is seen in the toughness level. The cemented carbide with 10 wt% CoCrNiCuMn shows the highest toughness value of 7.05 MPa·m^1/2. 展开更多
关键词 High-entropy alloy Cemented carbide nonstoichiometric TiN0.3
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A-site defects in LaSrMnO_(3) perovskite-based catalyst promoting NOx storage and reduction for lean-burn exhausts 被引量:4
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作者 Dongyue Zhao Yuexi Yang +4 位作者 Zhongnan Gao Ye Tian Jing Zhang Zheng Jiang Xingang Li 《Journal of Rare Earths》 SCIE EI CAS CSCD 2021年第8期959-968,共10页
Herein,we report the high De-NOx performance of the A-site defective perovskite-based Pd/La_(0.5)Sr_(0.3)MnO_(3) catalyst.The formation of the defective perovskite structure can be proved by both the increased Mn^(4+)... Herein,we report the high De-NOx performance of the A-site defective perovskite-based Pd/La_(0.5)Sr_(0.3)MnO_(3) catalyst.The formation of the defective perovskite structure can be proved by both the increased Mn^(4+)/Mn^(3+) ratio and serious lattice contraction due to cationic nonstoichiometry.It promotes the Sr doping into perovskite lattice and reduces the formation of the SrCO_(3) phase.Our results demonstrate that below 300℃ the A-site defective perovskite can be more efficiently regenerated than the SrCO_(3) phase as NOx storage sites due to the latter’s stronger basicity,and also exhibits the higher NO oxidation ability than the A-site stoichiometric and excessive catalysts.Both factors promote the lowtemperature De-NOx activity of the Pd/La_(0.5)Sr_(0.3)MnO_(3) catalyst through improving its NOx trapping efficiency.Nevertheless,above 300℃,the NOx reduction becomes the determinant of the De-NOx activity of the perovskite-based catalysts.A-site defects can weaken the interactions between perovskite and Pd,inducing activation of Pd sites by in-situ transformation from PdO to metallic Pd in the alternative leanburn/fuel-rich atmospheric alternations,which boosts the De-NOx activity of the Pd/La_(0.5)Sr_(0.3)MnO_(3) catalyst.The Pd/L_(0.5)Sr_(0.3)MnO_(3) catalyst exhibits the high sulfur tolerance as well.These findings provide insight into optimizing the structural properties and catalytic activities of the perovskite-based catalysts via tuning formulation,and have potential to be applied for various related catalyst systems. 展开更多
关键词 Dc-NOx nonstoichiometric perovskite Pd NOx storage and reduction Lean-burn exhausts Rare earths
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Sr^(2+)掺杂及非化学计量LaFeO_3的溶剂热制备及光催化性能 被引量:3
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作者 孙凤霞 谢燊坤 +1 位作者 崔艳丽 周德凤 《复合材料学报》 EI CAS CSCD 北大核心 2016年第8期1755-1761,共7页
利用简单的溶剂热法制备LaFeO_3、La_(0.8)Sr_(0.2)FeO_(3-δ)以及非化学计量的La_(0.8)Sr_(0.2)FeO_(3-δ)(x=0.97,1.03)纳米颗粒。采用XRD、TEM、UV-Vis、XPS等手段对样品的形貌和结构进行表征,以孔雀石绿(MG)光降解为模型反应,在最... 利用简单的溶剂热法制备LaFeO_3、La_(0.8)Sr_(0.2)FeO_(3-δ)以及非化学计量的La_(0.8)Sr_(0.2)FeO_(3-δ)(x=0.97,1.03)纳米颗粒。采用XRD、TEM、UV-Vis、XPS等手段对样品的形貌和结构进行表征,以孔雀石绿(MG)光降解为模型反应,在最大吸收波长下(616.9nm)考察材料的光催化性能。结果表明:Sr^(2+)的掺入减小了晶粒尺寸,致使晶体产生晶格畸变并形成氧空位V··O,抑制电子-空穴重组,增大量子效率;掺入Sr^(2+)并改变非化学计量,使得催化剂在可见光区域有较强的光吸收,比表面积增大,其中(La_(0.8)Sr_(0.2))1.03FeO_(3-δ)的比表面积最大(20.164 4m2/g),可见光降解效率也最高(83.8%)。Sr^(2+)掺杂及非化学计量LaFeO_3的可见光催化活性均高于纯LaFeO_3。 展开更多
关键词 LAFEO3 掺杂 溶剂热 非化学计量 光催化活性
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Research on mechanical alloying and sintering of TiC/Ti powders
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作者 Sun Jinfeng,Li Xiaopu,Wang Mingzhi,Zhao Yucheng (State Key Laboratory of Metastable Materials Science & Technology,Yanshan University, Qinhuangdao 066004,Hebei,China) 《金刚石与磨料磨具工程》 CAS 北大核心 2008年第S1期168-171,共4页
In order to improve the sintering activity of TiC which was usually added into the binder of polycrystalline diamond(PCD) and polycrystalline cubic boron nitride(PCBN),the powders of TiC and Ti mixed as molar ratio of... In order to improve the sintering activity of TiC which was usually added into the binder of polycrystalline diamond(PCD) and polycrystalline cubic boron nitride(PCBN),the powders of TiC and Ti mixed as molar ratio of TiC:Ti = 1:0.3 were treated by mechanical alloying.The structure and the morphology of the milled powders were analyzed by X-ray diffraction(XRD) and scan electron microscope(SEM), respectively.The milled powders were sintered by cubic hinge press.The structure of the sintered sample was analyzed by X-ray diffraction and the hardness was tested.The results showed that the grain size of the TiC and the Ti powders were decreased,as the milling time increased,and the nonstoichiometric compound of TiC_x was formed.The sintering activity of the TiC/Ti powders treated by mechanical alloying increased greatly.The hardness of the sintered sample improved from 829.2 HV for the raw powders to 2587.37 HV for the powders mechanical alloyed 20 hours. 展开更多
关键词 BINDER TiC SINTERING nonstoichiometric compound HARDNESS
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Microstructure and electrochemical characteristics of nonstoichiometric La-rich AB_5-type alloy for Ni/MH battery electrode
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作者 MAZhihong QIUJufeng +1 位作者 CHENLixin LEIYongquan 《Rare Metals》 SCIE EI CAS CSCD 2005年第1期65-70,共6页
The nonstoichiometric La-rich mischmetal (designated by MI)-based hydrogen storage alloy with a composition of MI(Ni0.64Co0.2Mn0.12Al0.04)(4.76) was prepared by arc melting and annealed at 1173 K for 10 h to investiga... The nonstoichiometric La-rich mischmetal (designated by MI)-based hydrogen storage alloy with a composition of MI(Ni0.64Co0.2Mn0.12Al0.04)(4.76) was prepared by arc melting and annealed at 1173 K for 10 h to investigate the effect of annealing treatment on the microstructure and electrochemical characteristics of the alloy. X-ray diffraction analysis showed that annealing can cause a release of the crystal lattice strain and an increase in amounts of the La2Ni7-type second phase in MI(Ni0.64Co0.20Mn0.12Al0.04)(4.76) alloy. Scanning electron microscopy and electron probe microanalysis examinations indicated that annealing leads to disappearance of the dendrite structure in the as-cast alloy, growth of crystal grain, and decrease of composition segregation. The annealing at 1173 K for 10 h flattened and extended the potential plateau and increased the maximum discharge capacity to 328 mA center dot h/g from 310 mA center dot h/g and the cycling life. The mechanism of the improvement in electrochemical characteristics was discussed based on the alloy microstructure change induced by annealing. 展开更多
关键词 metal material MICROSTRUCTURE electrochemical characteristics ANNEALING nonstoichiometric LaNi5-type alloy Ni/MH battery electrode
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非化学计量比AgSbTe_(2+x)化合物制备及热电性能 被引量:2
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作者 杜保立 徐静静 +1 位作者 鄢永高 唐新峰 《物理学报》 SCIE EI CAS CSCD 北大核心 2011年第1期765-771,共7页
采用高纯元素直接熔融、淬火并结合放电等离子烧结方法制备了非化学计量比AgSbTe2+x(x=0—0.05)系列样品,研究了不同Te含量在300—600K范围内对样品热电性能的影响规律.结果表明:随着Te含量的增加,Ag+离子空位浓度增加,空穴浓度和电导... 采用高纯元素直接熔融、淬火并结合放电等离子烧结方法制备了非化学计量比AgSbTe2+x(x=0—0.05)系列样品,研究了不同Te含量在300—600K范围内对样品热电性能的影响规律.结果表明:随着Te含量的增加,Ag+离子空位浓度增加,空穴浓度和电导率大幅度提高,Seebeck系数减小.热导率随Te过量程度的增加略有增加,但所有Te过量样品的晶格热导率均介于0.32—0.49W/mK之间,低于化学计量比样品的值,接近理论最低晶格热导率.AgSbTe2.01(x=0.01)样品具有最佳的综合热电性能,其热电优值ZT在562K达到1.41,与AgSbTe2化合物相比增加了15%. 展开更多
关键词 AgSbTe2 非化学计量比 热电性能 热导率
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高压烧结对n型PbTe基材料热电性能的影响 被引量:2
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作者 陈波 孙振亚 +2 位作者 黎明发 王善禹 范端 《高压物理学报》 EI CAS CSCD 北大核心 2012年第2期121-126,共6页
采用高压烧结技术制备了按偏离化学计量比配制的PbTe基热电材料(Pb0.55Te0.45),重点研究了烧结压力对材料热电性能的影响。研究结果表明:高压烧结过程能有效降低材料中的晶格缺陷,从而显著改变样品中的载流子浓度及其迁移率。与未经烧... 采用高压烧结技术制备了按偏离化学计量比配制的PbTe基热电材料(Pb0.55Te0.45),重点研究了烧结压力对材料热电性能的影响。研究结果表明:高压烧结过程能有效降低材料中的晶格缺陷,从而显著改变样品中的载流子浓度及其迁移率。与未经烧结的常压熔融样品相比,高压烧结样品的Seebeck系数得到大幅提高,电导率略有降低,室温热导率降低了50%,所以高压烧结样品的品质因子得到较大提高。当烧结压力为2GPa时,所得样品在700K时其品质因子达到0.59,相比未经烧结的常压熔融样品提高了150%。 展开更多
关键词 高压烧结 偏离化学计量比 Pb0.55Te0.45 热电性能
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La_(0.6)Nd_(0.4)Ni_(4.8)Mn_(0.2)Cu_x(x=0~0.4)贮氢合金的晶体结构及热力学性能(英文) 被引量:2
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作者 李慎兰 程宏辉 +3 位作者 邓小霞 陈伟 陈德敏 杨柯 《稀有金属材料与工程》 SCIE EI CAS CSCD 北大核心 2008年第10期1696-1700,共5页
研究了Cu含量变化对La0.6Nd0.4Ni4.8Mn0.2Cux(x=0,0.1,0.2,0.3,0.4)合金系的晶胞参数、热力学性能以及贮氢性能的影响,讨论了晶胞参数与吸放氢平台压力以及吉布斯自由能之间的关系。研究结果表明,随着Cu含量的增加,晶胞参数a增加,c减小... 研究了Cu含量变化对La0.6Nd0.4Ni4.8Mn0.2Cux(x=0,0.1,0.2,0.3,0.4)合金系的晶胞参数、热力学性能以及贮氢性能的影响,讨论了晶胞参数与吸放氢平台压力以及吉布斯自由能之间的关系。研究结果表明,随着Cu含量的增加,晶胞参数a增加,c减小,晶胞体积先增大后减小;吸放氢平台压力随着晶胞参数a的增加呈线性降低;La0.6Nd0.4Ni4.8Mn0.2Cux合金的Seitz半径随着Cu含量的增加而减小,并且与△Sd/ △Hd之间呈现非常好的线性关系,与△Sa/ △Ha之间存在双曲线关系。 展开更多
关键词 贮氢合金 非化学计量比 平台压力 晶胞参数 热力学性能
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MgO·(Al_2O_3)_n尖晶石单晶体的制备及相关特性研究 被引量:2
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作者 李华彬 伍登学 +1 位作者 赵汇川 林理彬 《功能材料》 EI CAS CSCD 1993年第4期362-367,共6页
本文运用高温固相反应法和焰熔生长方法制备了非化学配比的MgO·(Al_2O_3)_n(其中n=1.0,1.3,1.5,2.0,2.3,2.5,2.7,3.0,4.5,5.0)尖晶石微粉及单晶体。并用XRD,SEM,TG/DTA,IR及常规测试手段分析了实验结果,认为尖晶石粉料具有高纯度... 本文运用高温固相反应法和焰熔生长方法制备了非化学配比的MgO·(Al_2O_3)_n(其中n=1.0,1.3,1.5,2.0,2.3,2.5,2.7,3.0,4.5,5.0)尖晶石微粉及单晶体。并用XRD,SEM,TG/DTA,IR及常规测试手段分析了实验结果,认为尖晶石粉料具有高纯度、粉粒细且均匀、分散性好,以及白度好等特点。选择适当的n值,晶体容易生长且有较好的光学质量。化学分析表明;尖晶石有较好的化学性能,机械性能也好。因此,非化学配比的尖晶石既是短波长激光基质材料、陶瓷材料,也是优良的宝石饰品材料,可制成闪光的钻石和美丽的月长石代用品。 展开更多
关键词 固相反应法 尖晶石单晶体 晶体
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一种非化学计量钛氧化物的制备和表征 被引量:1
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作者 张涛 吴介达 +1 位作者 牛明勤 范莹莹 《同济大学学报(自然科学版)》 EI CAS CSCD 北大核心 2003年第5期627-630,共4页
用钛粉和草酸反应制得前驱物 ,在氮气保护下 6 0 0℃热分解前驱物制备了一种非化学计量钛氧化物 .讨论了前驱物的组成和热分析结果 ,对其化学式进行了推断 ,并从组成、颜色、比表面积等方面对产物进行了表征 .认为前驱物的化学式可能是T... 用钛粉和草酸反应制得前驱物 ,在氮气保护下 6 0 0℃热分解前驱物制备了一种非化学计量钛氧化物 .讨论了前驱物的组成和热分析结果 ,对其化学式进行了推断 ,并从组成、颜色、比表面积等方面对产物进行了表征 .认为前驱物的化学式可能是TiC2 O4·2H2 O .热分析的结果表明前驱物的热分解可分为三个过程 ,并且将热分解温度控制在 6 0 0℃可以保证前驱物的完全分解 .X射线粉末衍射分析 (XRD)结果显示产物中包含Ti2 O和TiO2两相 .本法制得的产物比表面积大 ,黑色度高 。 展开更多
关键词 非化学计量 氧化钛 制备 热分解
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浅谈非整比化合物 被引量:1
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作者 提淑华 王丽君 《沈阳教育学院学报》 2000年第1期104-107,共4页
金属过量、金属短缺缺陷。
关键词 非整比化合物 晶体 金属过量 负离子空位数
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Enhanced dual plasmonic photocatalysis through plasmonic coupling in eccentric noble metal-nonstoichiometric copper chakogenide hetero-nanostructures
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作者 Mariia Ivanchenko Vida Nooshnab +3 位作者 Alline F.Myers Nicolas Large Andrew J.Evangelista Hao Jing 《Nano Research》 SCIE EI CSCD 2022年第2期1579-1586,共8页
The extension of plasmonics to materials beyond the conventional noble metals opens up a novel and exciting regime after the inspiring discovery of characteristic localized surface plasmon resonances(LSPRs)in doped se... The extension of plasmonics to materials beyond the conventional noble metals opens up a novel and exciting regime after the inspiring discovery of characteristic localized surface plasmon resonances(LSPRs)in doped semiconductor nanocrystals originating from the collective oscillations of free holes in the valence band.We herein prepare colloidal monodisperse eccentric dual plasmonic noble metal-nonstoichiometric copper chalcogenide(Au@Cu_(2-x)Se)hybrid hetero-nanostructures with precisely controlled semiconductor shell size and two tunable LSPRs in both visible(VIS)and near-infrared(NIR)regions associated with Au and Cu_(2-x)Se,respectively.Through systematic evaluations of the photocatalytic performance of Au@Cu_(2-x)Se upon sole NIR and dual VIS+NIR simultaneous excitations,we are capable of unambiguously elucidating the role of plasmonic coupling between two dissimilar building blocks on the accelerated photocatalytic reactions with greater rate constants from both experimental and computational perspectives.The significantly enhanced strength of the electromagnetic field arising from efficient plasmonic coupling under the excitation of two LSPRs results in the superior activities of dual plasmonic Au@Cu_(2-x)Se in photocatalysis.The new physical and chemical insights gained from this work provide the keystone for the rational design and construction of high-quality dual-or even multi-plasmonic nano-systems with optimized properties for widespread applications ranging from photocatalysis to molecular spectroscopies. 展开更多
关键词 dual plasmonic nonstoichiometric copper chalcogenides time-domain(FDTD) PHOTOCATALYSIS
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