To further enhance the corrosion resistance of micro-arc oxidation (MAO) coatings on magnesium alloys, this study proposes a novel approach for in situ incorporating tantalum oxide into MAO coating by pre-sputtering pure tantalum layer on magnesium surface. The results show that the uniformly distributed tantalum oxide enhances the chemical stability of the MAO coating. Compared to the normal MAO coating, the tantalum oxide-containing MAO coating exhibits superior corrosion resistance, inhibiting localized corrosion of the substrate. Additionally, tantalum oxide-containing MAO coating also improved the hydrophilicity of magnesium alloy in simulated body fluid. This innovative method contributes to the long-term service reliability of magnesium alloys, highlighting its potential applications as orthopedic implants.

Mg 81 Ni 19 -8wt.% REO (oxides of Lanthanum and Cerium) alloys were successfully prepared using mechanical alloying method with Mg-Ni alloy and REO powder. Phase analysis, structural characterization, and microstructure imagine of the alloys were conducted using X-ray diffraction (XRD), metallurgical microscope, and transmission electron microscopy (TEM) methods. Multi-phase structures, including the primary phase of Mg 2 Ni and several secondary phases of Mg + Mg 2 Ni, MgNi-LaO, and MgNi-CeO, were found in in the as-cast Mg 81 Ni 19 -8wt.% REO alloys. XRD and TEM results showed that Ce exhibits variable valence behavior at various stages, and the addition of REO promotes the nanocrystalline of the alloy. The hydrogen absorption capacity of ball-milled Mg 81 Ni 19 and Mg 81 Ni 19 -8wt.%REO alloy for 2 h at 343 K is 1.34 wt.% and 1.83 wt.%, which are much larger than 0.94 wt.% of as-cast Mg 81 Ni 19 alloy. The addition of REO led to a decrease of the thermal decomposition temperature of the alloy hydride by approximately 20 K and a reduction of the activation energy of the hydrogen desorption reaction by 10% and 13%, respectively.

Mg77+xNi20−xLa3 (x = 0, 5, 10, 15) alloys were successfully prepared by the vacuum induction melting method. The structural characterizations of the alloys were performed by using X-ray diffraction and scanning electron microscope. The effects of nickel content on the microstructure and hydrogen storage kinetic of the as-cast alloys were investigated. The results showed that the alloys are composed of a primary phase of Mg2Ni, lamella eutectic composites of Mg + Mg2Ni, and some amount of LaMg12 and La2Mg17. Nickel addition significantly improved the hydrogen-absorption kinetic performance of the alloy. At 683 K, Mg77Ni20La3 alloy and Mg82Ni15La3 alloy underwent hydrogen absorption and desorption reactions for 2 h, respectively, and their hydrogen absorption and desorption capacities were 4.16 wt.% and 4.1 wt.%, and 4.92 wt.% and 4.69 wt.%, respectively. Using the Kissinger equation, it was calculated that the activation energy values of Mg77Ni20La3, Mg82Ni15La3, Mg87Ni10La3 and Mg92Ni5La3 alloys were in the range of 68.5~75.2 kJ/mol, much lower than 150~160 kJ/mol of MgH2.

To improve the reversible kinetics and electrochemical performance of a Nd-Mg-Ni-based alloy, NdMg11Ni + x wt% Ni (x = 100 or 200) samples were prepared through combining the addition of Ni element and ball-milling technology. Meanwhile, the effects of the addition of Ni element and the duration of milling on the NdMg11Ni samples were researched. The results indicate that the addition of Ni element has a beneficial effect on the dynamics of the samples. Meanwhile, the milling duration also has a beneficial effect on the high-rate discharging capabilities, the gaseous hydrogenation rate, and the dehydrogenation dynamics. When the ball-milling time is increased from 5 h to 60 h, the value of Rd20 (the ratio of the dehydrogenation capabilities within 20 min to the saturated hydrogenation capabilities) is raised from 62.20% to 71.59% for the x = 200 sample, and from 58.03% to 64.81% for the x = 100 sample; this is believed to be due to a decline in the activation energy resulting from an increase in the Ni content and ball-milling time. In addition, the E-a value of NdMg11Ni + 200 wt% Ni with a ball-milling time of 60 h is 55.7 kJ mol(-1).

Taking A2B7-type hydrogen storage alloy La0.75Mg0.25Ni3.3Co0.25 as an investigation object,the electrochemical properties of the alloy electrode treated by various reducers were studied.The results show that the treatment of reducing agent has an obvious effect on the activation property (the number of activation was only 2 time).Compared with untreated alloy,the surface treatment on reducing agent can greatly improve ~e mechanical properties of the alloys.S100 for treatment on KBH4,N2H4,NaH2PO2 are75.33％,78.70％ and 89.29％,respectively.The high rate discharge performance of hydride electrode was analyzed from the point of kinetic view.The results show that the exchange current density I0 and limiting current density h of hydride electrode handling for KBH4,N2H4,NaH2PO2 can be increased successively.The change in cyclic voltammograms oxidation peak area and electricity peaks of the alloy electrodes was similar for I0 and IL.All of the above indicate that the reduction treatment on the surface can effectively improve the kinetics performance of hydrogen absorbing and releasing processes of hydride electrode.The improvement of the high-rate discharge ability can be ascribed to the effect of the charge-transfer on the alloy surface and hydrogen diffusion rates in bulk of alloy.

利用高分子导电聚合物的聚合反应对镁系贮氢合金Mg1.8Nd0.2Ni进行表面处理,采用SEM对合金颗粒表面的微观结构进行观察,合金表面形成了一层聚苯胺导电高分子包覆层.研究了不同表面处理时间和处理方式对合金电化学性能的影响,实验表明表面处理能提高材料的抗氧化、抗腐蚀性能,改善电极电化学反应性能延长电极的使用寿命.表面处理提高了合金的活化性能与循环稳定性,容量保持率从77.82％提高到86.31％.EIS图表明包覆层增加了电极表面电荷转移阻抗.Tafel极化曲线中腐蚀电位明显右移,抗腐蚀性能提高,导电高分子层的网状结构加速了氢原子的传导并且阻止了合金表面氧的渗透.另外通过动电位极化曲线发现,表面处理工艺使合金的内部缺陷得到了优化,氢在体相内的扩散速率明显增加.

Hydrogen storage composites Nd2Mg17-50 wt.%Ni-x wt.%CeO2（x=0, 0.5, 1.0, 1.5, 2.0） were obtained by induction-ball milling method. The catalytic effect of CeO2 on hydriding kinetics of Nd2Mg17-50 wt.%Ni composite was investigated. X-ray diffraction（XRD） and high resolution transmission electron microscopy（HRTEM）, selected area electron diffraction（SAED） analyses showed that Nd2Mg17-50 wt.%Ni alloy had a multiphase structure, consisting of NdMg12, NdMg2Ni, Mg2Ni and Ni phases and the addition of catalyst CeO2 prompted the composites to be partly transformed into amorphous strucutre. The CeO2 improved the maximum hydrogen capacity of Nd2Mg17-50 wt.%Ni alloy from 3.192 wt.% to 3.376 wt.%（x=1.0）. What’s more, the increment of diffusion coefficient D led to the faster hydriding kinetics, which was calculated by Avrami-Erofeev equation. The dehydrogenation temperature reduced from 515.54 to 504.72 K was mainly caused by the decrease of activation energy from 93.28 to 69.36 kJ /mol, which was proved by the Kissinger equation.

随着水泥行业的快速发展,高品质石灰石成为日趋紧缺的资源,合理有效地利用高镁质石灰石原料煅烧水泥熟料又被赋予更加重要的资源综合利用的意义.本文借助化学分析、岩相分析、胶砂试验研究、XRD等检测方法等,探讨了不同掺量的SO3对高镁熟料中方镁石含量、C3S晶粒尺寸及晶型的影响.结果表明:适当的SO3掺加量能够有效减少高镁熟料中方镁石含量,有利于高镁熟料中氧化镁的固溶,促进C3S晶粒尺寸的增大,稳定熟料中M1型C3S,提高熟料的力学性能,在SO3掺量为1％时,得到的熟料力学性能最好,为高镁石灰石今后在水泥行业的利用提供一定理论和实验依据.

通过对出炉镁渣采取控制风速冷却法制备出三种冷却速率的镁渣,用以研究镁渣冷却速率对其物化性能的影响.借助化学分析,物理性能检测,XRD,SEM,压汞等方法对三种冷却速率镁渣对比分析研究的结果表明:冷却速率快可显著增大镁渣的水化活性,提高强度,减小镁渣自身的膨胀效果;研究还表明,随着冷却速率加快,镁渣水化试样由向外膨胀行为逐渐表现为内部的自密实过程,这种自密实过程表现在镁渣样孔尺寸的不断减小甚至完全消失.

通过正交实验对Mg2Ni合金铈转化处理工艺进行了研究,结合扫描电子显微镜(SEM)、能量散射光谱(EDS)法分析了膜层的表面形貌,并利用Tafel极化曲线、电化学阻抗谱(EIS)等分析手段对膜层性能进行了测试,获得了室温下(25±5)℃最佳的成膜条件:Ce(NO3)3浓度为0.05 rnol/L,pH值为4,镀膜时间为10 min,成膜促进剂的添加量为2mL/L.结果表明,采用以Ce(NO3)3为主要成分的酸性处理液,可以在Mg2Ni合金表面形成一层淡黄色的具有颗粒状突起的转化膜,膜层主要以Ce和O元素为主;经成膜溶液处理后,合金的自腐蚀电位由-943.419mV正移到了-934.545 mV,合金与溶液表面的电荷转移阻抗值从0.174 9 Ω提高到了0.187 3 Ω,经过20个放电循环,合金的放电保持率由12.9％提高到了70％,说明铈转化处理可提高Mg2Ni合金的耐腐蚀性能,较好地改善合金的循环稳定性.

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.

研究了球磨添加CeO2对La2Mg17-50％(质量分数,下同)Ni复合合金的相结构和储氢性能的影响,并对合金的形貌和吸放氢性能进行了检测.XRD结果表明,球磨加入CeO2后,在La2Mg17-50％ Ni合金中除了Mg2Ni和Ni相外,产生CeMg12相.SEM形貌图清晰地看见CeO2附在La2Mg17-50％Ni合金表面上呈白色小颗粒.吸氢动力学性能表明,加入CeO2后,使La2Mg17-50％ Ni合金的最大吸氢量从3.298％增加到3.594％.添加CeO2后合金的最佳饱和吸氢温度降为200℃(3 MPa),且吸氢动力学性能提高至1 min内的吸氢量达到3.382％,是其最大吸氢量的94％.然而,CeO2在放氢过程中的积极作用并不明显.

The as-cast La2Mg17 with different amount of Ni powders were mixed through ball milling to produce a new type of La2Mg17-x wt.% Ni (x = 50, 100, 150, 200) alloy. The microstructures of the alloys were characterized by XRD technique, the results show that the crystal structure transfers to amorphous one with the increasing amount of Ni powders. La2Mg17 50 wt.% Ni alloy reaches the highest hydrogen absorption capacity of 5.13 wt.% at 300 degrees C under 2 MPa hydrogen pressure due to its amorphous structure. Furthermore, La2Mg17-50 wt.% Ni alloy expresses fast hydriding kinetics and absorbs 4.99 wt.% hydrogen gas in 200 s. The hydrogen desorption ability described as discharge capacity during electrochemical reaction is fade next to La2Mg17-200 wt.% Ni alloy, attributed to the less Mg2NiH4 with lower enthalpies and easier to release H-2. The maximum discharge capacity of La2Mg17-200 wt.% Ni alloy reaches to exciting 980.90 mAh/g, while the La2Mg17 alloy is only 18.10 mAh/g with inconspicuous improvement of cycle stability. These dramatic difference in electrochemical performance reflect the consequence of sluggish dehydriding process of La2Mg17-50 and 100 wt.% Ni alloys again. whereas La2Mg17-200 wt.% Ni alloy has lower resistance both on alloy surface and in the bulk. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

(Ba0.85Ca0.15)1−xPrx(Zr0.1Ti0.9)O3 (where 0<x<0.01, abbreviated as BCZT:xPr) ceramics were fabricated by conventional solid-state reaction method. The influence of dopant concentration and microstructure on photoluminescence, ferroelectric, and piezoelectric properties was systematically investigated. The results showed that the photoluminescence spectra of the samples exhibited strong green (530nm) and red (602nm) emissions upon excitation of the 430nm to 500nm light, which couples well with to the emission band of the commercial blue light-emitting diodes chips. The emission intensities were strongly dependent on the dopant concentration and crystallite size, which reached the optimal value when the crystallite size and dopant concentration were 8μm and 0.002mol, respectively. Meanwhile, a large piezoelectric response with d33=325pC/N was obtained for BCZT:0.002Pr near the morphotropic phase boundary. Therefore, the Pr-doped BCZT materials, simultaneously exhibiting excellent luminescent properties and high piezoelectric properties, may have significant technological promise in novel multifunctional devices.

采用感应熔炼法制备La0.75Mg0.25Ni3.4-xAl0.1 Cox (x=0.0,0.5,1.0)贮氢合金,研究了合金元素Co对Ni部分替代对合金相结构及电化学性能的影响.结果表明,合金由La2Ni7相、LaNi5相及LaMg2Ni9相组成.随Co含量的增加,合金电极活化次数变化不大,最大放电容量、循环稳定性呈现先增后减的趋势.合金的最大放电容量和循环保持率分别由x=0时的316.92 mA.h/g和61.83％增加到x=0.5时的340.31 mA·h/g和75.21％,而后减少到x=1.0时的333.22mA·h/g和66.70％.而合金的高倍率放电性能降低,当放电电流密度为900mA/g时,其倍率放电性能由62.49％(x=0)减小到53.68％(x=1.0).合金电极的极限电流、贮氢合金电化学反应电阻逐渐增大,其高倍率放电性能的降低源于电极表面的电子迁移速率和氢在合金体相中扩散速率的共同作用.

The germanium in polymetallic ores was dissolved by HNO3 + HF+H2 SO4 + HClO4 and was measured by hydride generation-atomic fluorescence spectrometry(AFS).The effects of some parameters such as the H3 PO4 concentration and KBH4 concentration,working parameters of the AFS instrument on the determination were studied and optimized by experiments.The allowable quantities of the interference elements were also invested. The detection limit of this method was 0.024 μg/g,RSD was in the range of 4.79% to 5.53% and the recovery of standard addition was 93.5% to 107.3%.The method was validated by determination of Ge in National Standard Reference Materials and the results were in agreement with certified values.

The effects of ball-milling time and addition of CeO2 on microstructures and electrochemical properties of La2 Mg17 +200% Ni composite alloys were investigated.The XRD results indicate that Ni peak disappears completely after ball milled 100 h,the structure of the alloy changes to amorphous,however,the longer ball milling time lead to the agglomeration and recrystallization.Small amount of CeO2 contributes to formation of amorphous structure.The characterization of electrochemical properties show that with the ball milling time increase from 80 h to 100 h and 120 h,the discharge specific capacities of La2 Mg17 +200% composite alloy are 326.9,352.1 and 352.6 mAh/g,respectively.When adding CeO2 to composite alloy,the discharge specific capacities increase again to 373.5,398.8 and 409.8 mAh/g.But the addition of CeO2 to the composite alloy does not improve the cycling retention rate much.The electrochemical impedance spectroscopy(EIS) spectra demonstrates that the addition of CeO2 reduces the electrochemical reaction impedance of alloy surface effectively,which improves electrical catalytic activity of the hydrogen storage alloy,leads to the high discharge capacity.The open circuit potential also indicates that CeO2 ad verses to enhance alloy corrosion resistance.

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 °C, however, the cycle stability decreased considerably. A series of kinetic 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).

The electrochemical properties of A2B7-type hydrogen storage alloy La1.5Mg0.5Ni6.5Co0.5 with Ni-Co-P electroless-deposition by the different reaction temperatures and without it were studied. The results show that the microencapsulated hydrogen storage alloy electrodes lead to some increase in the activation number,high-rate discharge ability,exchange current density and limiting current density with increasing reaction temperature. The Ni-Co surface microencapsulation has a little effect on the cyclic stability. All of the above indicate that the Ni-Co-P electrochemical depositing method can effectively improve the electrochemical performance of hydrogen storage alloy electrodes.