Influence of zinc on electrochemical discharge activity of Mg-6%Al-5%Pb anode

Mg-6%Al-5%Pb (mass fraction) anodes with different contents of zinc were prepared by melting and casting. The electrochemical discharge behavior of these anodes in 3.5% NaCl solutions was investigated by galvanostatic test and electrochemical impedance spectroscopy (EIS). The microstructures and the corroded surfaces of these anodes were studied by scanning electron microscopy (SEM) and emission spectrum analysis (ESA). The phase structures and the corrosion products of the anodes were analyzed by X-ray diffraction (XRD). The results show that zinc promotes the grain refinement of Mg-6%Al-5%Pb anode and makes the average discharge potential of Mg-6%Al-5%Pb anode more negative during galvanostatic test. Mg-6%Al-5%Pb anode with the addition of 1% (mass fraction) zinc has the best electrochemical performance. The activation mechanism of zinc to Mg-6%Al-5%Pb anode is as follows: The hydrolyzation of dissolved Zn²⁺ ions reduces the pH value of the solution near the surface of the anode and accelerates the dissolution of Mg(OH)₂ film; The precipitated Zn(OH)₂ with similar structure as Mg(OH)₂ combines with Mg(OH)₂ film easily and makes it break down.     

苯的二级相干反斯托克斯喇曼散射

相干反斯托克斯喇曼散射(CARS)的特点在于它落在无萤光的很大的光谱区内,S/N比高,其强度比自发喇曼散射强几个数量级,而且有方向性。因此,这种技术引起激光喇曼光谱学的革命性变化。它可以被用于测量喇曼介质的非线性极化率,测量极低浓度的溶液或气体浓度以及含H_2火焰中的H_2浓度和温度。近几年来已引起物理、化学和生物学界很大的兴趣。 CARS过程有一共同点:要求既要实现共振(满足频率差ωp-ωs_1=△ω相当于一个     

喇曼与红外分子能量转移研究初探

在分子光谱领域,喇曼光谱与红外光谱是其研究的两种重要手段,它们相辅相成,相得益彰。迄今为止,这两种方法都是分开来研究的。喇曼光谱是一种光的非弹性散射现象,由感应偶极矩的变化引起,喇曼光谱接收在可见区,对光源强度要求较高,但一种频率的光源可以激发多条喇曼线;而红外光谱,它由固有偶极矩的变化引起,接收是在红外区,一般要有     

有机酸添加剂强化石灰石湿法烟气脱硫过程的实验研究

在湍球塔设备上进行了有机酸添加剂强化石灰石湿法烟气脱硫过程的实验研究,测定了进口SO2浓度、液气比、浆液pH及石灰石浆液浓度等对脱硫率的影响规律,以及不同有机酸作用下脱硫率、浆液pH等随时间的变化情况.实验结果表明,所选有机酸中己二酸的强化作用最强,柠檬酸的缓冲作用最强.     

苯的二级相干反斯托克斯喇曼散射(CARS)

设计了一套光路布置使用受激喇曼散射为相干光源,泵浦光子同受激光子之间混频,观测到苯的相干反斯托克斯喇曼散射共振现象,并获得很强的第二级相干反斯托克斯喇曼线.     

Influence of Mg21Ga5Hg3 compound on electrochemical properties of Mg-5%Hg-5%Ga alloy

The Mg-Hg-Ga alloys are widely used in high power the seawater batteries. Mg-5%Hg-5%Ga alloy was melted and heat treatments at 573-773 K were performed for different times. The electrochemical and corrosion behaviors of the Mg-5%Hg-5%Ga alloy were studied by means of potentiodynamic, galvanostatic and electrochemical impedance spectroscopy(EIS). Scanning electron microscopy(SEM), energy dispersive spectrometry(EDS) and X-ray diffractometry(XRD) were employed to characterize the microstructures of the alloy. The results demonstrate that the best electrochemical activity occurs in the Mg-5%Hg-5%Ga alloy with homogeneously dispersed Mg21Ga5Hg3 compound in α-Mg matrix. The most negative mean potential at 100 mA/cm2 polarization current density can reach -1.928 V. The largest corrosion current density 19.37 mA/cm2 of the Mg-5%Hg-5%Ga alloy appears in the Mg-5%Hg-5%Ga alloy with intergranular eutectic α-Mg and Mg21Ga5Hg3.     

GaP:N晶体中束缚激子的辐射跃迁及其能量转移

使用调QYAG:Nd激光器的三倍频脉冲光(λ=355nm)激发GaP:N晶体,测量了9.3～72.2K温度范围内样品的光致发光,研究了在10～250ns不同延迟时间的分辨光谱;借助瞬态谱仪和多道分析器测量了PL谱中NN_1、NN_2荧光强度衰减曲线。     

浅谈筛板对湍球塔脱硫性能的影响

在研究湍球塔中有机酸盐强化石灰石湿法烟气脱硫的过程中,讨论了支撑板对湍球塔性能的影响,考查了几种筛板的流体力学性能及其对脱硫率的影响。试验结果表明,随着喷淋密度的增加,膨胀床层高度和塔阻力都增加。在试验条件下,均匀开孔筛板的性能优于非均匀开孔筛板。     

Ce添加对AP65镁合金显微组织及电化学性能的影响

采用熔炼铸造法制备添加不同含量Ce的AP65镁合金。采用X射线衍射(XRD)、扫描电镜(SEM)和电子探针(EPMA)研究Ce对AP65镁合金显微组织的影响。采用恒电流放电、动电位极化扫描、化学浸泡研究不同Ce含量AP65镁合金的腐蚀电化学行为。结果表明:随Ce含量增加,合金中依次出现棒状或簇状的Al4Ce相和块状的Al2Ce相。Ce的添加导致AP65镁合金的电化学性能明显提高,添加0.6%(质量分数)的Ce使AP65镁合金的平均放电电位从-1.648 V(vs SCE)负移到-1.756 V(vs SCE);添加4%的Ce使AP65镁合金具有较小的腐蚀电流密度(19.66μA/cm2)和较高的阳极利用率(84.3%),与未添加Ce的AP65镁合金相比,阳极利用率提高16.6%。