检索结果-南通市图书馆

Structure and electrochemical properties of A_2B_7-Type La-Mg-Ni Hydrogen Storage Alloys

第五届中国有色合金及特种铸造国际会议

作者： M．Omidi A．Shafyei R．Ebrahimi-Kahrizsangi I．Maghsoudi Materials Engineering Department Islamic Azad University-Najafabad BranchIsfahanIran Materials Engineering Department Isfahan University of TechnologyIsfahanIran

＜正＞The presence of anode impurities in varied forms in the final product of aluminum alloys castings affects their physical,chemical and mechanical *** electrochemical properties of sacrificial anodes produced through casting are also affected by these *** investigate the effect of these oxide impurities on Al-Zn-In electrochemical properties,three methods of increasing the height of pouring,increasing retrogression,and stirring the melt were employed to determine and specify the amount of reduction in electrochemical properties（capacity current,potential and efficiency）by entering oxide impurities into the *** presence of oxide crusts resulting from the melt turbulence during pouring can encourage nucleation of blowholes by providing a non-wetted surface and have an extra effect on the capacity *** presence of floating oxides in the melt imprisoned in the piece after solidification is another factor in the reduction of the capacity *** investigate the effect of pouring height on the functioning of anode,a melt with a temperature of 750℃ was poured into the mold from the heights of 30,60,120,240,360, and,480 millimeters and after each stage a sample was taken for subsequent *** effect of retrogression was studied by employing the amounts of 15,30,45,and 60 percent by weight from the alloy *** stirring of the melt within 1,2,3,4,and 5 minutes while entering surface oxides into the melt was effective in the reduction of the electrochemical *** results showed that the three mentioned factors had negative effects on the electrochemical features of the anodes.

关键词： Aluminium Sacrificial Anode Efficiency Oxide Impurities electrochemical properties

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Journal of Rare Earths 2006年第5期24卷 625-625页

作者： Zhang Faliang Luo Yongchun Zhang Yongchao Deng Anqiang Kang Long Chen Jianhong State Key Laboratory of Gansu Advanced Non-Ferrous Metal Materials Lanzhou University of Technology Lanzhou 730050 China

Investigation of alloy structure shows that La2-xMgxNi7 （x = 0.3 - 0.8） alloys are mainly com- posed of Ce/Ni7-type, Gd2Co7-type and PuNi3-type phase. The influence of Mg content in alloys on the phase structure is great, resulting in a linear decrease of the unit cell parameters of main phases and increase of hydrogen absorption/desorption plateau as Mg content increases. electrochemical measurements show that as the Mg content increases, the discharge capacity of alloy electrodes first increases and then decreases. The cyclic stability presents a deteriorative trend. La1.4Mg0.6 Ni7 alloy electrode exhibits the maximum electrochemical discharge capacity （378 mAh·g^-1）, and the La1.6Mg0.4Ni7 alloy electrode shows the best cyclic stability （S270 = 81%）.

关键词： hydrogen storage alloy A2B7-type P-C-T isotherm electrochemical properties rare earths

Laser processing effects on Ti−45Nb alloy surface,corrosive and biocompatible properties

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2024年第8期34卷 2533-2551页

作者： I.CVIJOVIĆ-ALAGIĆ S.LAKETIĆ M.MOMČILOVIĆ J.CIGANOVIĆ Đ.VELJOVIĆ J.BAJAT V.KOJIĆ M.RAKIN Vinča Institute of Nuclear Sciences-National Institute of thеRepublic of Serbia University of BelgradeP.O.Box 52211001 BelgradeSerbia Faculty of Technology and Metallurgy University of BelgradeKarnegijeva 411120 BelgradeSerbia Oncology Institute of Vojvodina Faculty of MedicineUniversity of Novi SadPut Dr Goldmana 421204 Sremska KamenicaSerbia

The Ti−45Nb(wt.%)alloy properties were investigated in relation to its potential biomedical *** surface modification was utilized to improve its performance in biological *** a result of the laser treatment,(Ti,Nb)O scale was formed and various morphological features appeared on the alloy *** electrochemical behavior of Ti−45Nb alloy in simulated body conditions was evaluated and showed that the alloy was highly resistant to corrosion deterioration regardless of additional laser surface modification ***,the improved corrosion resistance after laser treatment was evident(the corrosion current density of the alloy before laser irradiation was 2.84×10^(−8)A/cm2,while that after laser treatment with 5 mJ was 0.65×10^(−8)A/cm2)and ascribed to the rapid formation of a complex and passivating bi-modal surface oxide *** cytotoxicity and effects of the Ti−45Nb alloy laser surface modification on the MRC-5 cell viability,morphology,and proliferation were also *** Ti−45Nb alloy showed no cytotoxic ***,cells showed improved viability and adherence to the alloy surface after the laser irradiation *** highest average cell viability of 115.37%was attained for the alloy laser-irradiated with 15 *** showed that the laser surface modification can be successfully utilized to significantly improve alloy performance in a biological environment.

关键词： Ti−45Nb alloy laser surface scanning electrochemical properties biocompatibility cell morphology

同方期刊数据库

Cation-doped LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) cathode with high rate performance

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第6期70卷 139-148页

作者： Long Zhang Dongsheng Yang Lilei Miao Chunmeng Zhang Jiexiang Li Jiawei Wen Chunxia Wang Tiantian Cao Guoyong Huang Shengming Xu College of New Energy and Materials China University of PetroleumBeijing 102249China State Key Laboratory of Heavy Oil Processing College of Chemical EngineeringChina University of PetroleumBeijing 102249China Beijing Spacecrafts Beijing 100094China SINOPEC Sales Co. Ltd.Beijing 100728China SINOPEC Research Institute of Petroleum Processing Co. LtdBeijing 100083China Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084China Beijing Key Laboratary of Fine Ceramics Tsinghua UniversityBeijing 100084China

The nickel-rich layered cathode material LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)has high energy density,lower cost and is a promising cathode material currently under ***,its electrochemical and structural stability is poor during *** the many modification methods,cation doping has been consistently proven to be an effective strategy for enhancing electrochemical ***,the NCM811 cathode material was modified by solid-phase reactions with Mg and Al *** addition,the corresponding mechanism of NCM811 cathode material-doped modification is explored by density functional theory(DFT)calculations,and we have extended this approach to other ternary cathode materials with different ratios and obtained universal *** with DFT calculations,the results show that Mg2+occupies the Li+site and reduces the degree of Li^(+)/Ni^(2+) mixture;Al^(3+) acts as a structural support during charging and discharging to prevent structural *** electrochemical properties were tested by an electrochemical workstation and the LAND system,and the results showed that the capacity retention rate increased to varying degrees from 63.66%to 69.87%and 89.05%for NCM811-Mg and NCM811-Al at room temperature after 300 cycles,*** study provides a theoretical basis and design strategy for commercializing cationic-doped modification of nickel-rich cathode materials.

关键词： Li-ion batteries Cathode materials Doped electrochemical properties DFT calculation

Copper-induced formation of heterostructured Co_(3)O_(4)/CuO hollow nanospheres towards greatly enhanced lithium storage performance

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第2期35卷 594-598页

作者： Junjun Zhang Huiying Lu Tianhao Yao Xin Ji Qingmiao Zhang Lingjie Meng Jianmin Feng Hongkang Wang College of Geography & Environment Xianyang Normal UniversityXianyang 712000China State Key Lab of Electrical Insulation and Power Equipment Center of Nanomaterials for Renewable Energy (CNRE)School of Electrical EngineeringXi'an Jiaotong UniversityXi'an 710049China School of Chemistry Xi'an Key Laboratory of Sustainable Energy Material Chemistryand Instrumental Analysis CenterXi'an Jiaotong UniversityXi'an 710049China

We report a facile template-free fabrication of heterostructured Co_(3)O_(4)/CuO hollow nanospheres using pre-synthesized Co/Cu-glycerate as conformal *** introduction of copper nitrate in the solvothermal reaction system of glycerol/isopropanol/cobalt nitrate readily induces the conversion from solid Co-glycerate to hollow Co/Cu-glycerate nanospheres,and the effect of the Co/Cu atomic ratio on the structure evolution of the metal glycerates as well as their corresponding oxides were *** examined as anode materials for lithium-ion batteries,the well-defined Co_(3)O_(4)/CuO hollow nanospheres with Co/Cu molar ratio of 2.0 demonstrate excellent lithium storage performance,delivering a high reversible capacity of 930 mAh/g after 300 cycles at a current density of 0.5 A/g and a stable capacity of 650 mAh/g after 500 cycles even at a higher current density of 2.0 A/g,which are much better than their counterparts of bare CuO and Co_(3)O_(4).The enhanced lithium storage performance can be attributed to the synergistic effect of the CuO and Co_(3)O_(4)heterostructure with hollow spherical morphology,which greatly enhances the charge/electrolyte transfer and effectively buffers the volume changes upon lithiation/delithiation cycling.

关键词： Lithium-ion batteries Co/Cu-glycerate Hollow nanospheres Co_(3)O_(4)/CuO heterostructure electrochemical properties

electrochemical Polymerization of Brilliant Cresyl Blue and properties of the Polymer

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2002年第6期20卷 583-590页

作者：杨一飞穆绍林 Department of Chemistry School of Science Yangzhou University Yangzhou Jiangsu 225002 China

The electrochemical polymerization of brilliant cresyl blue (BCB) has been carried out using cyclic voltammetry in the potential region between -0.20 V and 1.15 V (vs. Ag/AgCl with saturated KCl solution). The electrolytic solution consisted of BCB (0.1 mol/L) and Na 2HPO 4 (0.2 mol/L) with pH 2.1. BCB can not be polymerized at pHelectrochemical reversibility, fast charge transfer ability and stability in aqueous solutions with pH≤4.3. The visible spectrum, FTIR spectrum and Raman spectrum of poly(BCB) are different from those of BCB.

关键词： electrochemical polymerization poly(brilli^an^t cresyl blue) electrochemical properties visible spectra FTIR spectra Raman spectra

Effect of praseodymium substitution for lanthanum on structure and properties of La_(0.65-x)Pr_xNd_(0.12)Mg_(0.23)Ni_(3.4)Al_(0.1)(x=0.00–0.20) hydrogen storage alloys

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2009年第2期27卷 244-249页

作者：闫慧忠孔繁清熊玮李宝犬李金 Ruike National Engineering Research Center of RE Metallurgy & Functional Materials Baotou 014030China Baotou Research Institute of Rare Earth Baotou 014030China

In order to investigate the effect of substituting La with Pr on structural and hydrogen storage properties of La-Mg-Ni system （AB3.5-type） hydrogen storage alloys, a series of La0.65-xPrxNd0.12Mg0.23Ni3.4Al0.1（x=0, 0.10, 0.15, 0.2） hydrogen storage alloys were prepared. X-ray diffraction （XRD）, scanning electron microscopy （SEM） and energy dispersive spectrometer （EDS） analyses revealed that two alloys （x=0.0 and 0.10） were composed of （La,Mg）2（Ni,Al）7 phase, La（Ni,A1）5 phase and （La,Mg）Ni2 phase, while other alloys （x=0.15 and 0.20） consisted of （La,Mg）2（Ni,A1）7 phase, La（Ni,A1）5 phase, （La,Mg）Ni2 phase and （La,Mg）（Ni,A1）3 phase. All alloys showed, however, only one pressure plateau in P-C isotherms. The Pr/La ratio in alloy composition influenced hydrogen storage capacity and kinetics properties. electrochemical studies showed that the discharge capacity decreased from 360 mAh/g （x=-0.00） to 335 mAh/g （x=-0.20） as x increased. But the high-rate dischargeability （HRD） of alloy electrodes increased from 26% （x=0.00） to 56% （x=-0.20） at a discharge current density of Id=1800 mA/g. Anode polarization measurements were done to further understand the electrochemical kinetics properties after Pr substitution.

关键词： hydrogen storage alloy La-Mg-Ni system metal hydrides MH/Ni batteries electrochemical properties rare earths

Impedance and ferroelectric properties of Sr^(2+) modified PZT-PMN ceramics

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2014年第6期21卷 595-603页

作者： Arvind Kumar S.K.Mishra Research and Technology Development Centre Sharda University Dr. Harisingh Gour University

Sr^2＋ modified polycrystalline PZT-PMN ceramics were synthesized by a semi-wet route. Impedance spectroscopy studies indicate the bulk and grain boundary effects of PZT-PMN material along with the negative temperature coefficient of resistance. The bulk conductiv-ity exhibits an Arrhenius-type thermally activated hopping process which is supported by the AC conductivity behavior as a function of fre-quency and temperature. It is observed that the remnant polarization increases with an increase in the Sr2＋content in PZT-PMN.

关键词： piezoelectric ceramics ferroelectric materials ferroelectricity electrochemical properties strontium

Hydrogen storage properties of mechanically milled La_2Mg_(17-x)wt.%Ni(x=0,50,100,150 and 200) composites

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2013年第7期31卷 694-700页

作者：李霞赵栋梁张羊换许剑轶张国芳张胤 Department of Functional Material Research Central Iron and Steel Research Institute Inner Mongolia Key Laboratory for Utilization of Bayan Obo Multi-Metallic Resources:Elected State Key Laboratory Inner Mongolia University of Science and Technology School of Rare Earth Inner Mongolia University of Science and Technology

Melting method was used to obtain La2Mg17 alloy, and then Ni powder was added by mechanical alloying method. The kinetics of hydriding process and electrochemical properties of La2Mg17-X wt.%Ni （x=0, 50, 100, 150, 200） composites were investigated. X-ray diffraction （XRD） and scanning electron microscopy （SEM） analyses showed that the crystal structure of composite alloy gradually transformed into amorphous phase by the effect of ball milling and Ni powders. The research of hydrogen absorption properties found that La2Mg17-50 wt.%Ni reached the highest hydrogen absorption than other alloys with more addition of Ni content, reached to 5.796 wt.% at 3 MPa, and up to 5.229 wt.% merely in 2 min, which revealed that the amorphous phase reduced the H occupation of the lattice clearance, resulting in the decline of hydrogen absorption capacity. The electrochemical tests indicated that the maximum discharge capacity increased to 353.1 mAh/g at 30 ℃, however, the cycle stability decreased considerably./~ series of ki- netic measurements demonstrated that the controlling steps of electrochemical process of La2Mg17-x wt.%Ni alloys transferred from hydrogen diffusion on alloy bulk （x=50, 100） to hydrogen diffusion on both alloy bulk and surface （x=150, 200）.

关键词： hydrogen storage materials ball-milling electrochemical properties amorphous rare earths