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Electrochemical hydrogen storage characteristics of nanocrystalline and amorphous Mg_2Ni-type alloys prepared by melt-spinning 被引量:4
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作者 张羊换 吕科 +3 位作者 赵栋梁 郭世海 祁焱 王新林 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第3期502-511,共10页
The nanocrystalline and amorphous Mg2Ni-type alloys with nominal compositions of Mg2Ni1-xMnx (x=0, 0.1, 0.2, 0.3, 0.4) were synthesized by melt-spinning technique. The spun alloy ribbons with a continuous length, a ... The nanocrystalline and amorphous Mg2Ni-type alloys with nominal compositions of Mg2Ni1-xMnx (x=0, 0.1, 0.2, 0.3, 0.4) were synthesized by melt-spinning technique. The spun alloy ribbons with a continuous length, a thickness of about 30 μm and a width of about 25 mm are obtained. The structures of the as-spun alloy ribbons were characterized by XRD and HRTEM. The electrochemical hydrogen storage characteristics of the as-spun alloy ribbons were measured by an automatic galvanostatic system. The electrochemical impedance spectrums (EIS) were plotted by an electrochemical workstation. The hydrogen diffusion coefficients (D) in the alloys were calculated by virtue of potential-step measurement. The results show that all the as-spun (x=0) alloys hold a typical nanocrystalline structure, whereas the as-spun (x=0.4) alloy displays a nanocrystalline and amorphous structure, confirming that the substitution of Mn for Ni facilitates the glass formation in the Mg2Ni-type alloy. The substitution of Mn for Ni significantly improves the electrochemical hydrogen storage performances of the alloys, involving the discharge capacity and the electrochemical cycle stability. With an increase in the amount of Mn substitution from 0 to 0.4, the discharge capacity of the as-spun (20 m/s) alloy increases from 96.5 to 265.3 mA·h/g, and its capacity retaining rate (S20) at the 20th cycle increases from 31.3% to 70.2%. Furthermore, the high rate dischargeability (HRD), electrochemical impedance spectrum and potential-step measurements all indicate that the electrochemical kinetics of the alloy electrodes first increases then decreases with raising the amount of Mn substitution. 展开更多
关键词 mg2ni-type alloy electrochemical hydrogen storage MELT-SPINNING substituting Ni with Mn
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Sn元素对均匀态Mg-6Zn-0.25Ca镁合金耐腐蚀性能的影响
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作者 郭树国 刘绪栋 +2 位作者 贾征 寇荣辉 刘全 《稀有金属材料与工程》 北大核心 2025年第9期2345-2351,共7页
研究了添加1wt%的Sn对均匀态Mg-6Zn-0.25Ca合金耐腐蚀性能的影响。通过OM、XRD、SEM、析氢、失重以及极化曲线实验来分析Mg-6Zn-Sn-0.25Ca以及Mg-6Zn-0.25Ca 2种合金的耐腐蚀性能。结果表明,Mg-6Zn-0.25Ca合金主要第二相是Mg_(2)Ca相,... 研究了添加1wt%的Sn对均匀态Mg-6Zn-0.25Ca合金耐腐蚀性能的影响。通过OM、XRD、SEM、析氢、失重以及极化曲线实验来分析Mg-6Zn-Sn-0.25Ca以及Mg-6Zn-0.25Ca 2种合金的耐腐蚀性能。结果表明,Mg-6Zn-0.25Ca合金主要第二相是Mg_(2)Ca相,再加入Sn元素后,Mg-6Zn-Sn-0.25Ca合金中第二相的主要存在方式为Mg_(2)Sn相、Mg_(2)Ca相和少量CaMgSn相。加入Sn元素后,合金第二相分布更加均匀;合金的平均晶粒尺寸由145.6μm下降到了114.2μm,因为高熔点的Mg_(2)Sn相可以作为α-Mg基体非自发结晶的异质形核核心,从而细化晶粒尺寸。在两者共同作用下,合金因腐蚀而产生的腐蚀产物氧化膜更加绵密,阻止了析氢反应的继续进行。此外,极化曲线表明,Mg-6Zn-0.25Ca合金的自腐蚀电位和自腐蚀电流密度分别为–1.729 V和2.106×10^(–5)A/cm^(2),添加1wt%Sn元素后,自腐蚀电位升高到–1.525 V,自腐蚀电流密度减小为8.561×10^(–6)A/cm^(2),增强了Mg-6Zn-Sn-0.25Ca合金的耐蚀能力。 展开更多
关键词 mg-6Zn-0.25Ca合金 mg-6Zn-Sn-0.25Ca合金 均匀化 mg2Sn相 耐蚀性能
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Y元素对均匀态Mg-6Zn-0.25Ca镁合金耐蚀性能的影响
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作者 郭树国 刘全 +2 位作者 贾征 寇荣辉 刘绪栋 《稀有金属材料与工程》 北大核心 2025年第8期2136-2141,共6页
研究了Y元素对均匀态Mg-6Zn-0.25Ca合金耐蚀性能的影响。通过XRD、OM、SEM、失重、析氢和极化曲线实验研究了均匀态Mg-6Zn-0.25Ca和Mg-6Zn-1Y-0.25Ca这2种合金的微观组织及耐蚀性能。研究表明,均匀态Mg-6Zn-0.25Ca合金的第二相是Mg_(2)... 研究了Y元素对均匀态Mg-6Zn-0.25Ca合金耐蚀性能的影响。通过XRD、OM、SEM、失重、析氢和极化曲线实验研究了均匀态Mg-6Zn-0.25Ca和Mg-6Zn-1Y-0.25Ca这2种合金的微观组织及耐蚀性能。研究表明,均匀态Mg-6Zn-0.25Ca合金的第二相是Mg_(2)Ca,加入Y元素后平均晶粒尺寸稍有变大,Mg_(2)Ca相减少,还生成新的第二相Mg_(12)ZnY、Mg_(3)Y_(2)Zn_(3),并且第二相体积分数增加且分布更加均匀,这使得在腐蚀试验中镁基体上形成更加致密的腐蚀膜,该腐蚀膜可以起到屏障作用,新生成的Mg_(12)ZnY、Mg_(3)Y_(2)Zn_(3)都分布在晶界附近或枝晶间,显著降低了合金在腐蚀液中的电化学活性。这些使得Mg-6Zn-0.25Ca合金在3.5wt%NaCl的溶液中氢气析出量减少,增加Y元素使Mg-6Zn-0.25Ca合金的自腐蚀电位提高,并且减小自腐蚀电流密度,即有效地增强了均匀态Mg-6Zn-0.25Ca合金的耐蚀性能。所以Mg-6Zn-1Y-0.25Ca合金的耐蚀性能远高于Mg-6Zn-0.25Ca合金。 展开更多
关键词 mg-6Zn-0.25Ca合金 mg-6Zn-1Y-0.25Ca合金 均匀化 耐蚀性能 mg_(2)Ca相
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利用盐湖镁资源制备Mg(OH)_(2)技术研究进展
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作者 宋学文 朱海斌 +3 位作者 唐紫薇 李明菲 穆思成 罗仙平 《环境化学》 北大核心 2025年第9期2350-2364,共15页
氢氧化镁具有许多优良和独特的物理化学性质,在工业生产领域得到了广泛的关注和应用.盐湖镁资源是制备高纯氢氧化镁产品的重要来源,利用盐湖镁资源制备高性能氢氧化镁产品在科学领域和实际应用领域都具有极大的意义.本文系统地综述了目... 氢氧化镁具有许多优良和独特的物理化学性质,在工业生产领域得到了广泛的关注和应用.盐湖镁资源是制备高纯氢氧化镁产品的重要来源,利用盐湖镁资源制备高性能氢氧化镁产品在科学领域和实际应用领域都具有极大的意义.本文系统地综述了目前利用盐湖镁资源生产氢氧化镁的制备方法、制备工艺以及制备工艺参数对氢氧化镁结晶和成核过程以及物理化学性能影响的研究进展.指出了每种制备方法的优缺点,各个制备工艺的优点及不足和制备工艺参数的主要作用及今后的研究和发展方向.总结了不同制备方法、制备工艺和工艺参数对氢氧化镁结晶过程的影响和作用机理,以及形成过程中的主要作用.氢氧化镁作为重要的无机功能材料,开展盐湖镁资源制备氢氧化镁的研究可以促使氢氧化镁大规模应用得到快速发展. 展开更多
关键词 盐湖镁资源 氢氧化镁 沉淀剂 制备方法 反应条件
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Mg掺杂对TiO_(2)薄膜光学性能影响
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作者 王玉新 张虹宇 +3 位作者 周正凯 张心怡 李燕鑫 宋欣 《辽宁师范大学学报(自然科学版)》 2025年第3期373-380,共8页
以无水乙醇作为溶剂采用溶胶-凝胶法(Sol-gel)制备了Mg掺杂浓度分别为0at%、1.50at%、2.00at%、2.50at%、3.00at%的TiO_(2)薄膜.并利用X射线衍射仪(XRD)、X射线光电子能谱仪(XPS)、扫描电子显微镜(SEM)、原子力显微镜(AFM)和紫外-可见... 以无水乙醇作为溶剂采用溶胶-凝胶法(Sol-gel)制备了Mg掺杂浓度分别为0at%、1.50at%、2.00at%、2.50at%、3.00at%的TiO_(2)薄膜.并利用X射线衍射仪(XRD)、X射线光电子能谱仪(XPS)、扫描电子显微镜(SEM)、原子力显微镜(AFM)和紫外-可见分光光度计(UV-Vis)对Mg掺杂的TiO_(2)薄膜的结构、形貌和光学性能进行研究.结果表明,Mg掺杂的TiO_(2)薄膜仍为锐钛矿相,并取(101)晶面择优生长.与未掺杂TiO_(2)薄膜相比平均晶粒尺寸明显降低,且在紫外区域薄膜吸光度有所提高.其中,当Mg掺杂量为2.00at%时,TiO_(2)薄膜结晶质量最佳,平均晶粒尺寸最小为23.5439nm,薄膜表面孔隙最少,表面致密光滑,吸光度最高且带隙值最小为3.06eV. 展开更多
关键词 TiO_(2)薄膜 溶胶-凝胶法 mg掺杂 光学性能 晶体结构
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^(99m)Tc-EC肾动态显像联合Um-Alb、Uβ_(2)-MG可有效诊断原发性干燥综合征肾损害
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作者 崔璨 温庆祥 +4 位作者 孟元 田蕾 路素言 顾文 石瑾 《分子影像学杂志》 2025年第6期678-683,共6页
目的探讨肾动态显像联合尿微量白蛋白(Um-Alb)、尿β_(2)-微球蛋白(Uβ_(2)-MG)诊断原发性干燥综合征(pSS)肾损害的价值。方法回顾性分析2019年1月~2023年12月于本院就诊的pSS患者52例,其中肾损害组33例,非肾损害组19例。收集患者的肾... 目的探讨肾动态显像联合尿微量白蛋白(Um-Alb)、尿β_(2)-微球蛋白(Uβ_(2)-MG)诊断原发性干燥综合征(pSS)肾损害的价值。方法回顾性分析2019年1月~2023年12月于本院就诊的pSS患者52例,其中肾损害组33例,非肾损害组19例。收集患者的肾功能曲线参数(达峰时间、半排时间及20 min残留率)、ERPF、Um-Alb、Uβ_(2)-MG并比较其在肾损害组和非肾损害组患者之间的差异,比较ERPF、Um-Alb和Uβ_(2)-MG及三者联合对pSS肾损害的诊断效能,构建最佳诊断效能的联合模型并用列线图可视化该模型。结果两组达峰时间均无明显延长,肾损害组半排时间及20 min残留率升高,其ERPF低于非肾损害组,Um-Alb和Uβ_(2)-MG均高于非肾损害组(P<0.05)。ERPF、Um-Alb和Uβ_(2)-MG对pSS肾损害的诊断效能较高,其曲线下面积分别为0.813、0.859和0.850,三者联合的曲线下面积达0.992。结论肾动态显像及ERPF联合Um-Alb、Uβ_(2)-MG能有效诊断pSS肾损害,临床医师可根据列线图模型预测pSS肾损害的风险并及早进行干预。 展开更多
关键词 原发性干燥综合征 肾动态显像 尿微量白蛋白 尿Β2-微球蛋白 诊断价值
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缺陷多级孔Mg-MOF-74的制备与CO_(2)吸附性能
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作者 白皓 刘奕杰 +1 位作者 安海飞 王刚 《工业加热》 2025年第5期1-5,15,共6页
在冶金工业烟气碳捕集、利用与封存(CCUS)技术领域,开发兼具高吸附容量和优异选择性的吸附材料是突破当前技术瓶颈的关键。Mg-MOF-74材料CO_(2)吸附容量大,在冶金煤气捕集方面具有巨大的应用潜力,但是其存在的孔道单一、传质阻力大等问... 在冶金工业烟气碳捕集、利用与封存(CCUS)技术领域,开发兼具高吸附容量和优异选择性的吸附材料是突破当前技术瓶颈的关键。Mg-MOF-74材料CO_(2)吸附容量大,在冶金煤气捕集方面具有巨大的应用潜力,但是其存在的孔道单一、传质阻力大等问题,因此创新性地提出利用氯离子的弱配位特性构建缺陷工程策略,利用Cl^(-)与Mg^(2+)的弱配位作用,造成有机配体缺失,从而在微孔骨架内部形成由缺陷位点贯通产生的介孔及大孔网络,构建起三维贯通的多级孔道体系。这种独特的孔结构进一步提高了Mg-MOF-74的CO_(2)吸附量与CO_(2)/N_(2)的选择吸附性,更加适用于冶金煤气的碳捕集。 展开更多
关键词 冶金煤气 CCUS CO_(2)吸附 选择性 mg-MOF-74
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一种对作物Mg^(2+)活体检测的全固态微针型传感器制备及应用 被引量:1
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作者 王志豪 樊成孝 +2 位作者 王焯 黄岚 王忠义 《农业工程学报》 北大核心 2025年第9期29-36,共8页
镁元素对作物的生长发育至关重要,通过监测作物体内镁离子的浓度变化,即可监测作物的生长状态。为实现作物茎杆Mg^(2+)快速准确原位活体检测,研制了一款微针型全固态离子选择性电极(all-solid-state ion-selective electrodes,ASS-ISEs... 镁元素对作物的生长发育至关重要,通过监测作物体内镁离子的浓度变化,即可监测作物的生长状态。为实现作物茎杆Mg^(2+)快速准确原位活体检测,研制了一款微针型全固态离子选择性电极(all-solid-state ion-selective electrodes,ASS-ISEs)。该传感器以不锈钢微针为导电基底材料,在其尖端构建石墨烯-聚(3,4-乙烯二氧噻吩)/聚(苯乙烯磺酸盐)(PEDOT)固态转接层,并在固态转接层表面涂附离子选择性敏感膜(ion selective membrane,ISM)。首先,对传感器进行电位校准;然后,通过扫描电子显微镜(scanning electron microscopy,SEM)测试、水层测试、电化学阻抗谱(electrochemical impedance spectroscopy,EIS)测试等传感器性能表征方法,对针-石墨烯-PEDOT-ISM型和针-ISM型两种传感器进行对比测试;最后,将传感器应用于小麦苗茎秆Mg^(2+)原位活体检测,并设置对照试验。结果表明,传感器响应时间为7.0 s,检测限低至1.0×10^(-7) mol/L、能斯特斜率为27.04 mV/dec,寿命可达30 d以上;两种传感器的水层测试及EIS测试结果表明,石墨烯-PEDOT固态转接层结构,可以显著增加离子选择性薄膜和不锈钢基底之间的低频电容,有效抑制水层的形成,降低传感器表面的电荷转移电阻,减少信号漂移,提高响应电位的稳定性。小麦苗茎杆Mg^(2+)原位活体检测结果及纯琼脂和去离子水对照试验结果表明,该传感器可以有效检测其茎杆中Mg^(2+)浓度变化,变化范围为10^(-3.42)~10^(-3.03) mol/L,检测结果可靠。综上所述,该传感器检测限低、电位响应稳定,可用于作物茎秆Mg^(2+)浓度变化原位活体检测,应用前景广泛。 展开更多
关键词 传感器 作物mg^(2+)检测 石墨烯 电位校准
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Mg改性CuZnAlY催化剂对CO_(2)加氢制甲醇性能影响
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作者 王雷 崔海涛 +4 位作者 李国强 李枫 李彪 刘刚 李磊 《洁净煤技术》 北大核心 2025年第3期72-82,共11页
CO_(2)加氢制备甲醇是实现“双碳”目标的重要途径,通过添加不同含量的Mg对CuZnAlY催化剂进行改性,并系统研究了其对CO_(2)加氢制甲醇性能的影响。通过XRD、TPR、TPD和XPS等表征手段对催化剂结构特征进行了系统分析。结果表明,Mg的添加... CO_(2)加氢制备甲醇是实现“双碳”目标的重要途径,通过添加不同含量的Mg对CuZnAlY催化剂进行改性,并系统研究了其对CO_(2)加氢制甲醇性能的影响。通过XRD、TPR、TPD和XPS等表征手段对催化剂结构特征进行了系统分析。结果表明,Mg的添加构筑了合适的碱性位点,增强了CO_(2)吸附能力,提升了CO_(2)转化率和甲醇选择性。其中CZAYM_(2.5)复合催化剂时空产率最高,在T=250℃,P=3.0 MPa,GHSV=4000 mL/(mL·h),反应气n(H2)∶n(CO_(2))=3∶1(物质的量比)条件下,CO_(2)转化率、甲醇选择性和甲醇时空产率分别达到了18.95%、51.49%和0.1549 g/(g·h)。在提高反应压力P=5.0 MPa条件下进行了720 h稳定性试验。结果表明:CO_(2)转化率达到了22.00%,CH_(3)OH选择性保持在63.00%左右,时空产率保持在0.2100 g/(g·h)左右,催化剂表现出良好的稳定性能。 展开更多
关键词 CO_(2)排放 CO_(2)加氢 甲醇 复合催化剂 mg改性
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Gaseous and Electrochemical Hydrogen Storage Kinetics of As-quenched Nanocrystalline and Amorphous Mg_2Ni-type Alloys 被引量:4
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作者 张羊换 YANG Tai +3 位作者 SHANG Hongwei ZHANG Guofang CAI Ying ZHAO Dongliang 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2013年第3期604-611,共8页
The nanocrystalline and amorphous Mg2Ni-type Mg2Ni1-xCox (x = 0, 0.1, 0.2, 0.3, 0.4) alloys were synthesized by melt quenching technology. The structures of the as-cast and quenched alloys were characterized by XRD,... The nanocrystalline and amorphous Mg2Ni-type Mg2Ni1-xCox (x = 0, 0.1, 0.2, 0.3, 0.4) alloys were synthesized by melt quenching technology. The structures of the as-cast and quenched alloys were characterized by XRD, SEM and HRTEM. The gaseous hydrogen storage kinetics of the alloys was measured using an automatically controlled Sieverts apparatus. The alloy electrodes were charged and discharged with a constant current density in order to investigate the electrochemical hydrogen storage kinetics of the alloys. The results demonstrate that the substitution of Co for Ni results in the formation of secondary phases MgCo2 and Mg instead of altering the major phase Mg2Ni. No amorphous phase is detected in the as-quenched Co- ffee alloy, however, a certain amount of amorphous phase is clearly found in the as-quenched alloys substituted by Co. Furthermore, both the rapid quenching and the Co substitution significantly improve the gaseous and electrochemical hydrogen storage kinetics of the alloys, for which the notable increase of the hydrogen diffusion coefficient (D) along with the limiting current density (IL) and the obvious decline of the electrochemical impedance generated by both the Co substitution and the rapid quenching are basically responsible. 展开更多
关键词 mg2ni-type alloy rapid quenching substituting Ni with Co hydrogen storage kinetics
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Influences of melt spinning on electrochemical hydrogen storage performance of nanocrystalline and amorphous Mg_2Ni-type alloys 被引量:4
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作者 张羊换 李保卫 +3 位作者 任慧平 侯忠辉 胡峰 王新林 《Journal of Central South University》 SCIE EI CAS 2011年第6期1825-1832,共8页
In order to improve the electrochemical hydrogen storage performance of the Mg2Ni-type electrode alloys, Mg in the alloy was partially substituted by La, and the nanocrystalline and amorphous Mg2Ni-type Mg20-xLaxNi10 ... In order to improve the electrochemical hydrogen storage performance of the Mg2Ni-type electrode alloys, Mg in the alloy was partially substituted by La, and the nanocrystalline and amorphous Mg2Ni-type Mg20-xLaxNi10 (x-=0, 2) alloys were synthesized by melt-spinning technique. The microstructures of the as-spun alloys were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The electrochemical hydrogen storage properties of the experimental alloys were tested. The results show that no amorphous phase is detected in the as-spun Mg20Ni10 alloy, but the as-spun Mg18La2Ni10 alloy holds a major amorphous phase. As La content increases from 0 to 2, the maximum discharge capacity of the as-spun (20 m/s) alloys rises from 96.5 to 387.1 mA.h/g, and the capacity retaining rate (S20) at the 20th cycle grows from 31.3% to 71.7%. Melt-spinning engenders an impactful effect on the electrochemical hydrogen storage performances of the alloys. With the increase in the spinning rate from 0 to 30 m/s, the maximum discharge capacity increases from 30.3 to 135.5 mA.h/g for the Mg20Ni10 alloy, and from 197.2 to 406.5 mA-h/g for the Mg18La2Ni10 alloy. The capacity retaining rate (S20) of the Mg2oNi10 alloy at the 20th cycle slightly falls from 36.7% to 27.1%, but it markedly mounts up from 37.3% to 78.3% for the Mg18La2Ni10 alloy. 展开更多
关键词 mg2ni-type hydrogen storage alloy MELT-SPINNING STRUCTURE electrochemical performance
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An investigation of hydrogen storage kinetics of melt-spun nanocrystalline and amorphous Mg_2Ni-type alloys 被引量:3
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作者 张羊换 祁焱 +3 位作者 赵栋梁 郭世海 马志鸿 王新林 《Journal of Rare Earths》 SCIE EI CAS CSCD 2011年第1期87-93,共7页
The nanocrystalline and amorphous Mg2Ni-type Mg2- xLaxNi (x=0, 0.2) hydrogen storage alloys were synthesized by melt-spinning technique. The as-spun alloy ribbons were obtained. The microstructures of the as-spun ri... The nanocrystalline and amorphous Mg2Ni-type Mg2- xLaxNi (x=0, 0.2) hydrogen storage alloys were synthesized by melt-spinning technique. The as-spun alloy ribbons were obtained. The microstructures of the as-spun ribbons were characterized by X-ray diffraction (XRD), high resolution transmission electronic microscopy (HRTEM) and electron diffraction (ED). The hydrogen absorption and desorption kinetics of the alloys were measured using an automatically controlled Sieverts apparatus, and their electrochemical kinetics were tested by an automatic galvanostatic system. The electrochemical impedance spectrums (EIS) were plotted by an electrochemical workstation (PARSTAT 2273). The hydrogen diffusion coefficients in the alloys were calculated by virtue of potential-step method. The obtained results showed that no amorphous phase was detected in the as-spun La-free alloy, but the as-spun alloys substituted by La held a major amorphous phase, con- firming that the substitution of La for Mg markedly intensified the glass forming ability of the Mg2Ni-type alloy. The substitution of La for Mg notably improved the electrochemical hydrogen storage kinetics of the Mg2Ni-type alloy. Furthermore, the hydrogen storage kinetics of the experimental alloys was evidently ameliorated with the spinning rate growing. 展开更多
关键词 mg2ni-type hydrogen storage alloy MELT-SPINNING substituting mg with La hydrogen storage kinetics rare earths
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Influence of substituting Ni with Co on hydriding and dehydriding kinetics of melt spun nanocrystalline and amorphous Mg_2Ni-type alloys 被引量:2
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作者 张羊换 赵栋梁 +3 位作者 李保卫 马志鸿 郭世海 王新林 《Journal of Central South University》 SCIE EI CAS 2011年第2期303-309,共7页
In order to improve the hydriding and dehydriding kinetics of the Mg2Ni-type alloys,Ni in the alloy is substituted by element Co. The nanocrystalline and amorphous Mg2Ni-type Mg2Ni1-xCox (x=0,0.1,0.2,0.3,0.4) alloys w... In order to improve the hydriding and dehydriding kinetics of the Mg2Ni-type alloys,Ni in the alloy is substituted by element Co. The nanocrystalline and amorphous Mg2Ni-type Mg2Ni1-xCox (x=0,0.1,0.2,0.3,0.4) alloys were synthesized by melt-spinning technique. The structures of the as-cast and spun alloys were studied with an X-ray diffractometer (XRD) and a high resolution transmission electronic microscope (HRTEM). An investigation on the thermal stability of the as-spun alloys was carried out with a differential scanning calorimeter (DSC). The hydrogen absorption and desorption kinetics of the alloys were measured with an automatically controlled Sieverts apparatus. The results demonstrate that the substitution of Co for Ni does not alter the major phase of Mg2Ni but results in the formation of secondary phase MgCo2. No amorphous phase is detected in the as-spun Co-free alloy,but a certain amount of amorphous phase is clearly found in the as-spun Co-containing alloys. The substitution of Co for Ni exerts a slight influence on the hydriding kinetics of the as-spun alloy. However,it dramatically enhances the dehydriding kinetics of the as-cast and spun alloys. As Co content (x) increases from 0 to 0.4,the hydrogen desorption capacity increases from 0.19% to 1.39% (mass fraction) in 20 min for the as-cast alloy,and from 0.89% to 2.18% (mass fraction) for the as-spun alloy (30 m/s). 展开更多
关键词 mg2ni-type alloy MELT-SPINNING substituting NI Co structure HYDRIDING dehydriding KINETICS
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Gaseous and electrochemical hydrogen storage behaviors of nanocrystalline and amorphous Nd-added Mg_2Ni-type alloys 被引量:2
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作者 Yang-Huan Zhang Sheng-Long Liu +3 位作者 Tai Yang Guo-Fang Zhang Xia Li Dong-Liang Zhao 《Rare Metals》 SCIE EI CAS CSCD 2015年第7期463-471,共9页
Melt spinning technology was used to prepare the Mg2Ni-type(Mg24Ni10Cu2)100-xNdx(x = 0, 5, 10, 15,20) alloys in order to obtain a nanocrystalline and amorphous structure.The effects of the spinning rate on the structu... Melt spinning technology was used to prepare the Mg2Ni-type(Mg24Ni10Cu2)100-xNdx(x = 0, 5, 10, 15,20) alloys in order to obtain a nanocrystalline and amorphous structure.The effects of the spinning rate on the structures and gaseous and electrochemical hydrogen storage behaviors of the alloys were investigated.The analysis of X-ray diffraction(XRD), transmission electron microscope(TEM), and scanning electron microscope(SEM) linked with energy-dispersive spectroscopy(EDS)reveals that all the as-cast alloys hold a multiphase structure, involving the main phase Mg2 Ni and some secondary phases such as Mg6 Ni, Nd5Mg41, and Nd Ni.The as-spun Nd-free alloy displays an entire nanocrystalline structure,whereas the as-spun Nd-added alloys hold a nanocrystalline and amorphous structure, and the amorphization degree visibly increases with the spinning rate increasing.The melt spinning ameliorates the hydrogen storage performances of the alloys dramatically.When the spinning rate rises from 0(the as-cast was defined as the spinning rate of 0 m s-1) to 40 m s-1, the discharge capacity increases from 86.4 to 452.8 m Ah g-1, the S20(the capacity maintain rate at 20 th cycle) value increases from53.2 % to 89.7 %, the hydrogen absorption saturation ratio(Ra5, a ratio of the hydrogen absorption quantity in 5 min to the saturated hydrogen absorption capacity) increases from36.9 % to 91.5 %, and the hydrogen desorption ratio(Rd10,a ratio of the hydrogen desorption quantity in 10 min to the saturated hydrogen absorption capacity) increases from16.4 % to 47.7 % for the(x = 10) alloy, respectively. 展开更多
关键词 mg2ni-type alloy Element addition Melt spinning NA
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Influence of rapid quenching on hydrogen storage characteristics of nanocrystalline Mg_2Ni-type alloys 被引量:2
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作者 张羊换 赵栋梁 +3 位作者 李保卫 郭世海 祁焱 王新林 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第8期1439-1446,共8页
Nanocrystalline Mg2Ni-type alloys with nominal compositions of Mg20Ni10–xCux(x=0,1,2,3,4,mass fraction,%) were synthesized by rapid quenching technique.The microstructures of the as-cast and quenched alloys were char... Nanocrystalline Mg2Ni-type alloys with nominal compositions of Mg20Ni10–xCux(x=0,1,2,3,4,mass fraction,%) were synthesized by rapid quenching technique.The microstructures of the as-cast and quenched alloys were characterized by XRD,SEM and HRTEM.The electrochemical hydrogen storage performances were tested by an automatic galvanostatic system.The hydriding and dehydriding kinetics of the alloys were measured using an automatically controlled Sieverts apparatus.The results show that all the as-quenched alloys hold the typical nanocrystalline structure and the rapid quenching does not change the major phase Mg2Ni.The rapid quenching significantly improves the electrochemical hydrogen storage capacity of the alloys,whereas it slightly impairs the cycling stability of the alloys.Additionally,the hydrogen absorption and desorption capacities of the alloys significantly increase with rising quenching rate. 展开更多
关键词 mg2ni-type alloy rapid quenching hydrogen storage characteristic
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Highly Improved Gaseous Hydrogen Storage Characteristics of the Nanocrystalline and Amorphous Nd-Cu-added Mg_2Ni-type Alloys by Melt Spinning 被引量:1
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作者 Yanghuan Zhang Tingting Zhai +3 位作者 Baowei Li Huiping Ren Wengang Bu Dongliang Zhao 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2014年第10期1020-1026,共7页
The nanocrystalline and amorphous Mg-Nd-Ni-Cu quaternary alloys with a composition of (Mg24Ni10Cu2)loo-xNdx (x = 0-20) were prepared by melt spinning. The X-ray diffraction and transmission electron microscopy ins... The nanocrystalline and amorphous Mg-Nd-Ni-Cu quaternary alloys with a composition of (Mg24Ni10Cu2)loo-xNdx (x = 0-20) were prepared by melt spinning. The X-ray diffraction and transmission electron microscopy inspections reveal that, by varying the spinning rate and the Nd content, different microstructures could be obtained by melt spinning. Particularly, the as-spun Nd-free alloy holds an entire nanocrystalline structure but the as-spun Nd-added alloy has a nanocrystalline and amorphous structure, which implies that the addition of Nd facilitates the glass forming in the Mg2Ni-type alloy. Also, the degree of the amorphization in the as-spun Nd-added alloys clearly increases with increasing the spinning rate and the Nd content. The H-storage capacity and the hydrogenation kinetics of amorphous, partially and completely nanocrystalline alloys were investigated and it was found that they are dependent on the microstructure and the phase composition of the alloys. Specially, enhancing the spinning rate from 0 (the as-cast was defined as the spinning rate of 0 m/s) to 40 m/s makes the hydrogen absorption saturation ratio (R5a) (a ratio of the hydrogen absorption quantity in 5 min to the saturated hydrogen absorption capacity) increase from 35.2% to 90.3% and the hydrogen desorption ratio (R10d) (a ratio of the hydrogen desorption quantity in 10 min to the saturated hydrogen absorption capacity) rise from 12.7% to 44.9% for the (x = 5) alloy. And the growing of the Nd content from 0 to 20 gives rise to the R5a and R10d values rising from 85.7% to 94.5% and from 36.7% to 54.8% for the as-spun (30 m/s) alloys, respectively. 展开更多
关键词 mg2ni-type alloy Nd addition Melt spinning STRUCTURES Hydrogen storage
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钪和镁复合合金化对Al-10Mg_(2)Si合金组织与力学性能的影响
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作者 赵英 程婷 +3 位作者 秦纪康 伍复发 张莉 武晓峰 《中国稀土学报》 北大核心 2025年第3期595-602,共8页
利用光学显微镜、扫描电镜、X射线衍射仪、室温拉伸试验机等研究了Sc和Mg复合合金化对Al-10Mg_(2)Si合金显微组织、拉伸性能和断裂行为的影响。结果表明,在Al-10Mg_(2)Si合金中添加0.25%Sc能够使初生α-Al晶体的形貌由粗树枝状转变为近... 利用光学显微镜、扫描电镜、X射线衍射仪、室温拉伸试验机等研究了Sc和Mg复合合金化对Al-10Mg_(2)Si合金显微组织、拉伸性能和断裂行为的影响。结果表明,在Al-10Mg_(2)Si合金中添加0.25%Sc能够使初生α-Al晶体的形貌由粗树枝状转变为近球状,同时其晶粒尺寸大大减小;在进一步添加2.8%Mg后,初生α-Al晶粒变得更细、更均匀。另外,0.25%Sc和2.8%Mg的共同添加明显细化了合金中共晶Mg_(2)Si相晶体的尺寸,并且其形貌也由粗大的汉字状转变为细条状、颗粒状或点状。Sc和Mg对α-Al和共晶Mg_(2)Si相的细化、变质作用使得合金的拉伸性能得以大幅提高。共同添加0.25%Sc和2.8%Mg合金的拉伸性能最好,其值分别为345 MPa,145 MPa和8.6%,比未添加合金分别提高48%,41%和231%。 展开更多
关键词 Al-mg_(2)Si合金 Sc和mg复合合金化 共晶mg_(2)Si相 初生Α-AL 拉伸性能
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拉曼光谱测定透闪石-铁阳起石中Mg^(2+)、Fe^(2+)比值
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作者 于露 陈天虎 +4 位作者 戴慧 曹素巧 王枫 郭连巧 左锐 《岩石矿物学杂志》 北大核心 2025年第3期727-736,共10页
角闪石是分布广泛的造岩矿物之一,Mg^(2+)、Fe^(2+)相对含量是透闪石-铁阳起石系列定名的依据,对矿物学、岩石学、宝玉石学研究具有重要意义。本文收集了8个产地不同成因的透闪石-铁阳起石系列样品,开展了系统的拉曼光谱和电子探针定量... 角闪石是分布广泛的造岩矿物之一,Mg^(2+)、Fe^(2+)相对含量是透闪石-铁阳起石系列定名的依据,对矿物学、岩石学、宝玉石学研究具有重要意义。本文收集了8个产地不同成因的透闪石-铁阳起石系列样品,开展了系统的拉曼光谱和电子探针定量分析研究,发现样品在3600~3700 cm^(-1)区间的拉曼谱峰发生规律变化,峰面积与电子探针分析获得的镁、铁含量具有良好线性相关性,归纳出了利用拉曼谱峰面积计算透闪石-铁阳起石系列矿物中Mg^(2+)、Fe^(2+)比值的方法,可应用于透闪石-铁阳起石系列矿物的快速、无损分析。 展开更多
关键词 透闪石-铁阳起石 mg^(2+)、Fe^(2+)比值 拉曼谱峰面积 电子探针
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油酸钠体系中Ca^(2+)和Mg^(2+)对黄铁矿浮选行为的影响
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作者 张永志 唐云 +2 位作者 邓政斌 杨勇 杨叶艳 《黄金科学技术》 北大核心 2025年第2期360-368,共9页
为了探究Ca^(2+)和Mg^(2+)对黄铁矿浮选行为的影响,采用单矿物试验、浮选溶液化学计算、接触角、SEM、FTIR和XPS分析等方法,考察了油酸钠体系中Ca^(2+)和Mg^(2+)对黄铁矿浮选的影响规律及机理。单矿物浮选试验结果表明:在油酸钠体系中,C... 为了探究Ca^(2+)和Mg^(2+)对黄铁矿浮选行为的影响,采用单矿物试验、浮选溶液化学计算、接触角、SEM、FTIR和XPS分析等方法,考察了油酸钠体系中Ca^(2+)和Mg^(2+)对黄铁矿浮选的影响规律及机理。单矿物浮选试验结果表明:在油酸钠体系中,Ca^(2+)和Mg^(2+)的存在对黄铁矿的浮选行为产生活化,改善其浮选效果,但是随着pH值的增大,离子对黄铁矿的活化效果不断减弱;pH值较低时,钙和镁主要以Ca^(2+)和Mg^(2+)的形式吸附在黄铁矿表面,增加了黄铁矿表面对溶液中油酸钠的吸附量,且Ca^(2+)和Mg^(2+)会与油酸钠发生化学反应,生成油酸钙和油酸镁吸附在黄铁矿表面,使黄铁矿表面接触角增大从而改变了其表面疏水性;随着pH值的不断增大,黄铁矿表面的Fe-S键会断裂生成Fe(OH)_(3),阻碍离子吸附,且Ca^(2+)和Mg^(2+)的形态随着pH值的增大发生变化,起活化作用的Ca^(2+)和Mg^(2+)浓度不断降低,离子活化效果减弱。研究结果对使用油酸钠反浮选分离卡林型金矿中的黄铁矿和碳酸盐矿物具有一定指导意义。 展开更多
关键词 浮选 黄铁矿 CA^(2+) mg^(2+) 油酸钠 离子活化 接触角
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固相还原法合成Mg(Ⅱ)-α-Fe_(2)O_(3)纳米颗粒及其光催化性能
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作者 张敏 韦菲菲 +2 位作者 邓殷文 董怡 任根宽 《现代化工》 北大核心 2025年第5期158-162,共5页
在利用FeS还原硫酸亚铁制备α-Fe_(2)O_(3)纳米材料过程中加入少量的MgSO_(4),合成纳米Mg(Ⅱ)-α-Fe_(2)O_(3)材料,然后用于光催化降解废水中甲基橙。用X射线衍射(XRD)、傅里叶红外光谱(FT-IR)、扫描电子显微镜(SEM)测试技术分析合成纳... 在利用FeS还原硫酸亚铁制备α-Fe_(2)O_(3)纳米材料过程中加入少量的MgSO_(4),合成纳米Mg(Ⅱ)-α-Fe_(2)O_(3)材料,然后用于光催化降解废水中甲基橙。用X射线衍射(XRD)、傅里叶红外光谱(FT-IR)、扫描电子显微镜(SEM)测试技术分析合成纳米材料结构性能。分析表明,固相还原法成功合成具有类球形结构纯相纳米Mg(Ⅱ)-α-Fe_(2)O_(3)材料,平均纳米粒径为56 nm。光催化降解实验表明,初始质量浓度为15 mg/L、固液比为2 g/L、光照射45 min甲基橙降解率接近于100%。 展开更多
关键词 硫酸亚铁 黄铁矿 纳米mg(Ⅱ)-α-Fe_(2)O_(3) 固相还原法
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