一维锰基氧化物/氧化石墨烯的晶相结构对氧还原性能的影响

基于氧化石墨烯(graphene oxide,GO),以不同的锰源为原料,采用一步水热法合成两种不同晶相的锰基氧化物与GO的复合材料。样品分别经XRD、Raman、SEM及TEM进行结构、形貌表征。XRD测试结果表明合成的锰基氧化物分别为β-MnO_2和γ-MnOOH。Raman结果证明样品中GO的存在。SEM和TEM结果显示氧化物均为棒状结构,与GO复合后,形成了β-MnO_2/GO,γ-MnOOH/GO异相结构。循环伏安和旋转圆盘电极测试结果表明β-MnO_2/GO具有更为优异的氧还原催化活性,起始电位为-0.10 V(vs Hg/Hg O)。比较两种复合物,在-0.3 V(Hg/Hg O)电位下,β-MnO_2/GO具有比γ-MnOOH/GO更高的电流密度,这归因于β-MnO_2特别的晶相结构对氧还原的催化活性以及β-MnO_2和GO间优异的协同作用。这种新型β-MnO_2/GO复合材料有望成为一种价格低廉且高效的非贵金属氧还原催化剂。     

一些组合、数论问题的新发现

本文发现了关于πn(n≥2),mn-m,LUCAS,xn yn=zn,(a-b)n,nx,prime的新算法.     

Stability of Novel Time-Sharing Dual Optical Tweezers Using a Rotating Tilt Glass Plate

A novel realization of time-sharing optical tweezers （TSOT） is demonstrated using a tilt glass plate. Objects are trapped in the time-sharing dual traps; each of them acts like a single beam gradient trap with an effective stiffness. The effective stiffness of TSOT is experimentally measured through analysis of dynamical images. In comparison, it is numerically calculated by adopting the Monte Carlo technique. Both simulation and experimental results agree well with each other and show a good linear relationship between the effective stiffness and trap switching frequency in the range from 5 Hz to 70 Hz.     

Fibonacci数列之新发现

通过爬楼梯模型本人获得几个广义Fibonacci数列的新性质 .