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Rietveld法计算MH-Ni电池电极材料物相标准谱 被引量:8
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作者 王超群 王宁 李娜娜 《电源技术》 CAS CSCD 北大核心 2002年第6期445-447,共3页
用Rietveld分析法模拟计算MH Ni电池电极材料主要物相 [如 β Ni(OH) 2 ,γ NiOOH和LaNi5,La2 O3 与La(OH) 3等 ]标准X射线衍射谱 ,并根据多相体模型定量分析 (或称无标定量相分析法 )确定电极制备与充放电过程中少量第二相的含量。结... 用Rietveld分析法模拟计算MH Ni电池电极材料主要物相 [如 β Ni(OH) 2 ,γ NiOOH和LaNi5,La2 O3 与La(OH) 3等 ]标准X射线衍射谱 ,并根据多相体模型定量分析 (或称无标定量相分析法 )确定电极制备与充放电过程中少量第二相的含量。结果表明 :在峰形与峰宽参数选择合适以及无择优取向的条件下 ,模拟计算结果与参比强度法也即K值法[1]测算的结果相一致。该法的优点是可以给出全衍射谱的概念 。 展开更多
关键词 Rietveld法 计算 MH-NI电池 电极材料 物相标准谱 标准X射线衍射谱 定量相分析
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高能球磨法低温合成Mg_4Nb_2O_9纳米粉体 被引量:2
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作者 付志粉 马建立 +2 位作者 丁兰芳 吴怡 刘鹏 《陕西师范大学学报(自然科学版)》 CAS CSCD 北大核心 2009年第6期23-26,共4页
以MgO和Nb2O5为原料,用高能球磨法制备Mg4Nb2O9前驱体,前驱体经900℃热处理合成Mg4Nb2O9纳米粉体.采用X射线衍射和扫描电镜(Scanning Electron Microscopy,SEM)研究了粉体随合成温度、球磨时间、保温时间的微结构变化和物相转变过程.结... 以MgO和Nb2O5为原料,用高能球磨法制备Mg4Nb2O9前驱体,前驱体经900℃热处理合成Mg4Nb2O9纳米粉体.采用X射线衍射和扫描电镜(Scanning Electron Microscopy,SEM)研究了粉体随合成温度、球磨时间、保温时间的微结构变化和物相转变过程.结果表明,MgO-Nb2O5混合物经60 h高能球磨在900℃保温3 h合成出粒径为50~80 nm的Mg4Nb2O9纳米粉体.高能球磨法制备的粉体在1 200℃可烧结成致密的具有优异性能的Mg4Nb2O9陶瓷. 展开更多
关键词 高能球磨 纳米粉体 X射线衍射
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钢渣粉/聚酯纤维沥青混合料水稳定性研究 被引量:7
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作者 张抒幻 吴金荣 张涛 《科学技术与工程》 北大核心 2023年第2期785-793,共9页
为了实现钢渣粉在沥青路面中的可持续利用,同时结合河南省冬季冰雪天气下路面的除冰情况,研究了掺有聚酯纤维与钢渣粉沥青混合料的水稳定性。制备4种聚酯纤维掺量(0、0.3%、0.4%、0.5%)AC-13沥青混合料开展复盐(掺量配比为NaCl∶CaCl2∶... 为了实现钢渣粉在沥青路面中的可持续利用,同时结合河南省冬季冰雪天气下路面的除冰情况,研究了掺有聚酯纤维与钢渣粉沥青混合料的水稳定性。制备4种聚酯纤维掺量(0、0.3%、0.4%、0.5%)AC-13沥青混合料开展复盐(掺量配比为NaCl∶CaCl2∶CH2COONa=1∶1∶2)冻融循环劈裂试验,结果表明聚酯纤维掺量为0.4%时,沥青混合料水稳定最好;在最佳纤维掺量下制备5种替代率(0、25%、50%、75%、100%)钢渣粉沥青混合料,采用冻融劈裂抗拉强度比(freeze-thaw splitting tensile strength ratio,TSR)确定最佳钢渣粉替代率为75%,混合料水稳定性最佳;通过冻融腐蚀因子K评价沥青混合料的抗侵蚀性能,结果表明:聚酯纤维/钢渣粉沥青混合料的抗侵蚀性能最强,聚酯纤维沥青混合料次之,普通石灰岩沥青混合料最弱。通过电镜扫描(scanning electron microscope,SEM)、X射线衍射(X-ray diffraction,XRD)技术探索钢渣粉/聚酯纤维沥青混合料界面黏附作用的改性机理。微观分析表明:掺量为0.4%的聚酯纤维形成的纤维网状结构以及沥青、钢渣粉(75%的替代率)和矿粉三者存在界面能量作用可以很好地改善沥青混合料的水稳定性。 展开更多
关键词 聚酯纤维 钢渣粉 水稳定性 电镜扫描(scanning electron microscope SEM) X射线衍射(x-ray diffraction xrd)
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Electrochemical characterization of Ni-Co and Ni-Co-Fe for oxidation of methyl alcohol fuel with high energetic catalytic surface 被引量:4
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作者 Subir Paul Sk Naimuddin Asmita Ghosh 《燃料化学学报》 EI CAS CSCD 北大核心 2014年第1期87-95,共9页
Non Pt based metals and alloys as electrode materials for methyl alcohol fuel cells have been investigated w ith an aim of finding high electrocatalytic surface property for the faster electrode reactions.Electrodes w... Non Pt based metals and alloys as electrode materials for methyl alcohol fuel cells have been investigated w ith an aim of finding high electrocatalytic surface property for the faster electrode reactions.Electrodes w ere fabricated by electrodeposition on pure Al foil,from an electrolyte of Ni,Co,Fe salts.The optimum condition of electrodeposition w ere found out by a series of experiments,varying the chemistry of the electrolyte,pH valve,temperature,current and cell potential.Polarization study of the coated Ni-Co or Ni-CoFe alloy on pure Al w as found to exhibit high exchange current density,indicating an improved electro catalytic surface w ith faster charge-discharge reactions at anode and cathode and low overvoltage.Electrochemical impedance studies on coated and uncoated surface clearly show ed that the polarization resistance and impedance w ere decreased by Ni-Co or Ni-Co-Fe coating.X-ray diffraction(XRD),energy dispersive X-ray spectroscopy(EDX)and atomic absorption spectroscopy(AAS)studies confirmed the presence of alloying elements and constituents of the alloy.The morphology of the deposits from scanning electron microscope(SEM)images indicated that the electrode surface w as a three dimensional space w hich increased the effective surface area for the electrode reactions to take place. 展开更多
关键词 ELECTRODEPOSITION Ni-Co alloy ELECTROCATALYTIC exchange current density impedance x-ray diffraction(xrd) scanning electron microscope(SEM)
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Mechanism of cement-stabilized soil polluted by magnesium sulfate 被引量:3
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作者 韩鹏举 王帅 +1 位作者 陈幼佳 白晓红 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第5期1869-1877,共9页
In order to simulate and study the mechanism of cement stabilized soils polluted by different contents of magnesium sulfate(MS), a series of tests were conducted on the cemented soil samples, including unconfined comp... In order to simulate and study the mechanism of cement stabilized soils polluted by different contents of magnesium sulfate(MS), a series of tests were conducted on the cemented soil samples, including unconfined compression strength(UCS) tests of blocks, X-ray diffraction(XRD) phase analysis of powder samples, microstructure by scanning electronic microscopy(SEM),element composition by energy dispersive spectrometry(EDS), and pore distribution analysis by Image Processed Plus 6.0(IPP 6.0)software. The UCS test results show that UCS of cemented soils reaches the peak value when the MS content is 4.5 g/kg. While, the UCS for Sample MS4 having the MS content of 18.0 g/kg is the lowest among all tested samples. Based on the EDS analysis results,Sample MS4 has the greater contents for the three elements, oxygen(O), magnesium(Mg) and sulfur(S), than Sample MS1. From the XRD phase analysis, C-A-S-H(3Ca O·Al2O3·3Ca SO4·32H2O and 3Ca O·Al2O3·Ca SO4·18H2O), M-A-H(Mg O·Al2O3·H2O), M-S-H(Mg O·Si O2·H2O), Mg(OH)2 and Ca SO4 phase diffraction peaks are obviously intense due to the chemical action associated with the MS. The pore distribution analysis shows that the hydrated products change the distribution of cemented soil pores and the pores with average diameter(AD) of 2-50 μm play a key role in terms of the whole structure of cemented soil. The microscopic structure of the cemented soil with MS exhibits the intertwined and embedded characteristics between the cement and granular soils from the SEM images of cemented soils. The microstructure analysis shows that the magnesium sulfate acts as the additive, which is beneficial to the soil strength when the MS content is low(i.e., Sample MS2). However, higher MS amount involving a chemical action makes samples crystallize and expand, which is adverse to the UCS of cemented soils(i.e., Sample MS4). 展开更多
关键词 unconfined compression strength(UCS) magnesium sulphate(MS) x-ray diffraction(xrd) microstructure energy dispersive spectrometer(EDS)
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Mineralogy and Possible Sources of Dust Particles During One Asian Dust Episode
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作者 Longyi Shao,Weijun Li State Key Laboratory of Coal Resources and Safe Mining,Department of Resources and Earth Sciences,China University of Mining and Technology(Beijing),Beijing 100083,China. 《地学前缘》 EI CAS CSCD 北大核心 2009年第S1期108-108,共1页
A severe Asian Dust Storm(ADS)event occurred on April 16-17th,2006 in northem China.Mineral components of dust samples were analyzed using X-ray diffraction(XRD).The result indicates that dust particles were dominated... A severe Asian Dust Storm(ADS)event occurred on April 16-17th,2006 in northem China.Mineral components of dust samples were analyzed using X-ray diffraction(XRD).The result indicates that dust particles were dominated by quartz(37.4%)and clay (32.9%),followed by plagioclase(13.7%),with small amounts of calcite,K-feldspar,dolomite,homblende, and gypsum(all【10%).The clay fractions with diameter less than 2μm were separated from the 展开更多
关键词 ASIAN DUST Storm(ADS) MINERALOGY x-ray diffraction(xrd) clay MINERALS DUST aerosol mineral ratios
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