Influence of heat treatment on spectroscopic properties of Er3+ in multicomponent ZrF4-ZnF2-AlF3-YF3-MF2 (M = Ca, Sr, Ba) based glass

Er3+ doped multicomponent fluoride based glass was prepared. These precursor fluoride glass samples were then heated using different schedules. Crystalline phase particles were successfully precipitated in the multicomponent fluoride glass samples after heat treatment. The influence of heat treatment on the spectroscopic properties of Er3+ in multicomponent fluoride based glass samples were discussed. Small changes of the Judd-Ofelt parameters Omega(i) (i = 2,4,6) were found in multicomponent fluoride glass samples before and after heat treatment compared to oxyfluoride telluride glass. Preparation conditions used to produce transparent multicomponent fluoride glass ceramics doped with rare-earth ions are discussed. (c) 2007 Elsevier B.V. All rights reserved.

马铃薯蛋白酶仰制ll的基因克隆及对烟草的转化

马铃薯蛋白酶抑制剂Ⅱ(PinⅡ）是一种丝氨酸蛋白酶抑制剂，能同时具有抑制胰凝乳蛋白酶及胰蛋白酶胰凝乳蛋白酶的作用位点，饲喂幼虫含PinⅡ的饲料及转基因植物叶子的实验显示了较强的杀虫能力。为了获得一个广谱的抗虫基因用于增强植物对虫害的抵抗力，本文用PCR程序从马铃薯基因组中克隆了Pin II的基因，并构建了以CaMV 35S启动子驱动的表达PinⅡ的双元表达载体质粒，将其转入农杆菌，通过农杆菌介导的途径转化烟草，已在卡那霉素培养基上筛选出Km抗性的植株。