L-色氨酸在聚甲基红膜修饰电极上的电化学行为及其分析研究

用循环伏安法制备了聚甲基红膜修饰玻碳电极(PMRE/GCE)。研究了L-色氨酸(L-Trp)在该修饰电极上的电化学行为,探讨了不同缓冲溶液、pH以及扫描速率等的影响。实验表明:在pH=5.5的HAc-NaAc支持电解质中,L-Trp在PMRE/GCE上的电化学氧化反应是一不可逆过程,于0.783V(vs.SCE)处产生一灵敏的氧化峰,峰电流大大增加。氧化峰电流与L-Trp的浓度在2.0×10-6~1.0×10-3mol/L范围内呈良好的线性关系,检出限为8.0×10-7mol/L,样品检测平均回收率为100.16%。     

β-环糊精负载四甲基哌啶氮氧化物的合成及其在分子氧氧化醇反应中的催化性能

以乙烯基二胺为连接臂将四甲基哌啶氮氧化物(TEMPO)负载于β-环糊精(β-CD)上,得到负载型催化剂β-CD-TEMPO.采用~1H NMR、~(13)C NMR以及FT-IR等手段对β-CD-TEMPO进行了表征.将β-CD-TEMPO、CuBr_2以及K_2CO_3结合构成催化体系,用于分子氧为氧化剂的醇的选择性氧化反应,结果表明该体系对苄基以及烯丙基伯醇的氧化显示出良好的催化活性和选择性.在负载催化剂中,乙烯基二胺既作为连接臂又作为配体与铜离子配位,使氧化反应顺利进行.负载型催化剂β-CD-TEMPO与产物容易分离,能够循环使用.     

Fabrication of superconducting Nb N meander nanowires by nano-imprint lithography

Superconducting nanowire single photon detector(SNSPD), as a new type of superconducting single photon detector(SPD), has a broad application prospect in quantum communication and other fields. In order to prepare SNSPD with high performance, it is necessary to fabricate a large area of uniform meander nanowires, which is the core of the SNSPD. In this paper, we demonstrate a process of patterning ultra-thin Nb N films into meander-type nanowires by using the nanoimprint technology. In this process, a combination of hot embossing nano-imprint lithography(HE-NIL) and ultraviolet nano-imprint lithography(UV-NIL) is used to transfer the meander nanowire structure from the NIL Si hard mold to the Nb N film. We have successfully obtained a Nb N nanowire device with uniform line width. The critical temperature(Tc) of the superconducting Nb N meander nanowires is about 5 K and the critical current(Ic) is about 3.5 μA at 2.5 K.