Electrochemical Characteristics of Mg0.9Ti0.1-xZrxNi （x=0.02, 0.04, 0.06） Alloys

Mg-based hydrogen storage alloys Mg0.9Ti0.1-xZrxNi (x=0.02, 0.04, 0.06) were successfully prepared by means of mechanical alloying (MA). The effects of Zr addition on the discharge capacity and the cycle performance of the Mg-based electrodes were also studied. It was found that the discharge capacities were improved with addition of a small amount of Zr and the cycle performances of the alloy were stabilized with the addition of Ti. The effects of surface modification or coating on the properties of Mg0.9Ti0.06Zr0.04Ni were also studied. The results indicated that coating with graphite improved both the discharge capacity and cycle life of the amorphous Mg0.9Ti0.06Zr0.04Ni electrode.     

HDD工艺对NdFeB粘结磁体磁性能的影响

叙述了NdFeB合金成分、均匀化处理和HDD处理脱氢过程对磁性粉末及粘结磁体磁性能的影响。实验表明,HDD法制备的NdFeB磁性粉末及粘结磁体具有较好的温度稳定性和时间稳定性。     

四元Mg0.9Ti0.1Ni0.9X0.1(X=Mn,Zn,Co,Fe)系列合金的制备及性能研究

用机械合金化法合成了Mg0.9Ti0.1Ni0.9X0.1(X=Mn, Zn, Co, Fe)系列合金. X射线衍射(XRD)结构分析表明, 用X部分替代Ni后, 促进了Mg0.9Ti0.1Ni合金的非晶化过程. 用Co和Fe部分替代Ni提高了合金的放电容量, 但却降低了合金的循环稳定性. 用Zn和Mn部分替代Ni提高了合金电极的循环寿命, 尤其是Mg0.9Ti0.1Ni0.9Zn0.1合金电极经10个充放电循环后, 其放电容量仍可达到313.8 mA·h/g. 对添加Co后的合金进行p-c-T测试发现, Mg0.9Ti0.1Ni0.9Co0.1合金的吸放氢容量明显比Mg0.9Ti0.1Ni合金高, 这与电化学所测到的结果一致.     

α-Al2O3纳米粒子对Co-Ni合金异常共沉积电化学行为的影响

为了研究在电化学复合共沉积过程中,惰性纳米粒子和金属离子、电极表面的相互作用,以及由此产生的对合金电化学共沉积行为的影响.本文从两个吸附过程出发: 电解液中的金属离子和H＋在纳米粒子表面的吸附；纳米粒子迁移到阴极表面,在电极表面的吸附.采用Zeta电势和稳态极化以及电化学交流阻抗（EIS）研究了纳米Al2O3粒子和电解液中的金属离子，和电极表面的相互作用,进而分析了纳米粒子对Co2＋和Ni2＋还原沉积的影响规律.通过对阻抗数据的拟合,讨论了Al2O3纳米粒子对等效电路中各物理参数的影响.在H＋和不同金属离子在纳米粒子上发生竞争吸附的基础上,提出了纳米粒子和合金共沉积的可能反应历程.     

离子交换树脂负载Ni—B无定形合金催化剂的制备与性能

制备了一种新型离子交换树脂负载的Ｎｉ－Ｂ无定形合金催化剂．用３种树脂作为催化剂载体，即弱酸型阳离子树脂Ｄ１５２，强酸型阳离子树脂Ｄ７２及强碱型阴离子树脂Ｄ２６１．用ＸＰＳ、ＴＥＭ和ＩＣＰ等技术对催化剂进行了表征．结果表明，催化剂上镍与带有功能基的载体树脂之间有着很强的相互作用，但其强度与所带的功能基有关．３种催化剂Ｎｉ２ｐ３／２的ＸＰＳ谱图上，ＮｉＢ／Ｄ１５２催化剂的氧化态峰最小，而ＮｉＢ／Ｄ２６１的氧化态峰最大．异丙醇脱氢反应活性实验证实了这一结果．     

A Novel Carbon Nanotube-Supported NiP Amorphous Alloy Catalyst and Its Hydrogenation Activity

A carbon nanotube-supported NiP amorphous catalyst (NiP/CNT) was prepared by induced reduction. Benzene hydrogenation was used as a probe reaction for the study of catalytic activity. The effects of the support on the activity and thermal stability of the supported catalyst were discussed based on various characterizations, including XRD, TEM, ICP, XPS, H2-TPD, and DTA. In comparison with the NiP amorphous alloy, the benzene conversion on NiP/CNT catalyst was lower, but the specific activity of NiP/CNT was higher, which is attributed to the dispersion produced by the support, an electron-donating effect, and the hydrogen-storage ability of CNT. The NiP/CNT thermal stability was improved because of the dispersion and electronic effects and the good heat-conduction ability of the CNT support.     

纳米尺寸团簇NinZrn(n=3～5)的几何结构与成键规律研究

根据化学键理论与拓扑原理，设计了团簇NinZrn(n=3-5)的可能几何构型，并用从头算方法进行构型优化，结果表明，由NiZr组成的团簇原子间的Zr-Zr和Zr-Ni键明显较强，而Ni-Ni的成键较弱，并发与NinZrn(n=3-5)团簇电子性质与有机烯烃分子等瓣相似，原子之间的成键按照强弱相间的规则分布。     

柱前衍生-高效液相色谱法测定钢及合金中钨和钼

以tiron作为柱前衍生试剂,用含3mmol·L-1pH 3.8的HOAc-NaOAc,40mmol·L-1TBA-Br和2mmol·L-1tiron的甲醇-水溶液(53+47)作流动相,在C18柱上,于15min内实现了WO42-、MoO42-的分离测定。钨和钼的检出限分别为5.98和3.20ng·ml-1。方法快速,选择性好,用于钢及合金中高含量钨和钼的测定,结果与标准值相符。     

微量元素La对Al—Si合金凝固过程的影响

本文用差热分析法系统地研究了La掺杂对Al-Si共晶合金、亚共晶、超共晶的动态凝固过程的影响。结果表明,La促使α(Al)成核,使体系中初晶α(Al)的析出温度比AJ-Si二元合金中Al初晶的实际析出温度明显提高;La对初晶Si的成核和长大起抑制作用,使超共晶中初晶Si相析出温度较二元合金中的Si初晶的实际析出温度明显降低。