Design and preparation of pH-responsive curdlan hydrogels as a novel protein delivery vector

New pH-responsive saccharide hydrogels were designed and prepared using curdlan derivatives(curdlan-Bochistidine, CUR-HIS). The CUR-HIS hydrogels possessed highly porous structures. The swelling ratios of CUR-HIS hydrogels increased with the degree of substitution of Boc-histidine groups. And the addition of 0.5 mol/L Na Cl provoked a sharp reduction of swelling ratio of CUR-HIS hydrogels. Bovine serum albumin(BSA) can be efficiently encapsulated into CUR-HIS hydrogels. Moreover, the release profiles of BSA at different p H values from CUR-HIS hydrogels were significantly different. These hydrogels showed good biocompatibility in the cytotoxicity assays. The CUR-HIS hydrogels are of great potential in biomedical applications such as protein delivery systems.     

Uniform light emission from electrically driven plasmonic grating using multilayer tunneling barriers

Light emission by inelastic tunneling(LEIT)from a metal-insulator-metal tunnel junction is an ultrafast emission process.It is a promising platform for ultrafast transduction from electrical signal to optical signal on integrated circuits.However,existing procedures of fabricating LEIT devices usually involve both top-down and bottom-up techniques,which reduces its compatibility with the modern microfabrication streamline and limits its potential applications in industrial scale-up.Here in this work,we lift these restrictions by using a multilayer insulator grown by atomic layer deposition as the tunnel barrier.For the first time,we fabricate an LEIT device fully by microfabrication techniques and show a stable performance under ambient conditions.Uniform electroluminescence is observed over the entire active region,with the emission spectrum shaped by metallic grating plasmons.The introduction of a multilayer insulator into the LEIT can provide an additional degree of freedom for engineering the energy band landscape of the tunnel barrier.The presented scheme of preparing a stable ultrathin tunnel barrier may also find some applications in a wide range of integrated optoelectronic devices.     

Nb：KTiOPO4晶体的生长和倍频性能

通过研究晶体生长工艺参数对Nb∶KTiOPO4(Nb∶KTP)晶体生长的影响,用熔盐顶部籽晶法获得尺寸为55mm×25mm×5mm的Nb∶KTP透明单晶.研究中发现熔体的温度梯度、籽晶和降温速率将严重影响Nb∶KTP晶体的生长.Nb离子的引入不利于Nb∶KTP晶体的生长,尤其是造成晶体易开裂,且沿a轴方向生长速度非常缓慢.同时,Nb的引入大大改变Nb∶KTP晶体的倍频性能.掺杂Nb浓度的摩尔分数为13%时,Nb∶KTP晶体的倍频的Ⅱ型相位匹配的截止波长缩短至937nm,且有效产生469nm倍频蓝光;掺杂Nb浓度的摩尔分数为3%时,Nb∶KTP晶体对Nd∶YAG的1.0642μm激光倍频的最佳相位匹配角为θ=88.32°,()=0°,非常接近90°非临界相位匹配方向.     

叔丁基联苯基苯基噁二唑作空穴限制层的掺杂聚合物蓝光发光二极管

叔丁基联苯基苯基噁二唑作空穴限制层的掺杂聚合物蓝光发光二极管马於光,吴军,薛善华,黄劲松,田文晶,刘式墉,沈家骢,刘晓冬（吉林大学分子光谱与分子结构开放实验室,集成光电子学国家重点实验室,长春,１３００２３）（白求恩医科大学基础部）关键词聚合物,发光...     

酸催化剂浓度对钌络合物/溶胶-凝胶薄膜的发光氧气传感性能的影响

以正硅酸乙酯（TEOS）为原料在乙醇共溶剂和不同盐酸催化剂浓度条件下，采用溶胶－凝胶法制得含钌络合物发光分子Ru(dpp)^2 3的硅氧烷预聚液，通过旋转涂敷以及凝胶陈化干燥处理制备了一系列氧气敏感的发光薄膜。通过凝胶载体中发光分子在不同氧浓度下的发光猝灭行为，探讨了盐酸催化剂浓度对载体微结构和发光分子微环境的影响，结果表明：随着盐酸催化剂减小，薄膜的猝灭响应（Q），Stern-Volmer系数（Ksv)以及响应时间（猝灭时间tQ和恢复时间tR)均得到极明显的改善。传感器性能的改善主要归因于随着盐酸催化剂浓度减小，凝胶载体倾向于形成敞开的大孔道结构。     

Effect of High Resistance Phases on Metal—Insulator Transition of La0.67Ca0.33MnO3

The temperature dependence of resistivity ρ of YSZ doping composite of (1-x) La0.67Ca0.33MnO3 xYSZ and Y2O3 doping composite of (1-y) La0.67MnO3 yY2O3 is investigated,respectively,in a temperature range 77-300K,where the YSZ represents yttria-stabilized zirconia(8mol%Y2O3 92mol% ZrO2).Experimental results show that the YSZ doping level has important effects on both the metal-insulator(M-I) transition temperatures and zero field resistivity of the composites of (1-x) La0.67Ca0.33MnO3 xYSZ.However,the Y2O3 doping level has little effect on the M-I transition temperatures and the zero field resistivity of (1-y)La0.67Ca0.33MnO3 yY2O3 only increases slightly.The difference between the two types of composites may mainly results from the different distribution of high resistance phases at the grain boundaries and /or surfaces of La0.67Ca0.33MnO3 grains rather than the substitution of La^3 ions with Y^3 ions.     

EuSr2Ru1-xTaxCu2O8中Ta替代效应

通过对EuSr2Ru1-xTaxCu2O8(x=0.0,0.1,0.2,0.5和1.0)体系的结构、电阻和磁化强度的观测,发现EuSr2RuCu2O8(x=0.0)样品在130.2K以下呈现铁磁有序,在35K时发生了超导转变,并呈现典型的欠掺杂高温超导体特征;随着Ta对Ru替代浓度x值的增加,铁磁相变温度和超导临界温度均下降.对该体系中的元素替代效应,及其磁有序和超导电性的共存进行了讨论.     

1-丁烯在MCM-22分子筛中的吸附与扩散：Monte Carlo与动力学模拟研究

采用巨正则Monte Carlo方法和分子动力学方法研究了1-丁烯在MCM-22分子筛中的吸附现象和扩散行为,得到了1-丁烯吸附在该分子筛孔道中的相互作用能和在不同孔道中的扩散轨迹和扩散系数.结果表明1-丁烯在MCM-22分子筛中主要存存两个相互作用能区间,1-丁烯优先吸附在十元环孔道中;1-丁烯的扩散和移动主要发生在十二元环超笼的中部,十元环孔道中的1-丁烯扩散速度明显小于十二元环超笼系统中的扩散速度.     

可溶性聚（2，5－二丁基氧基苯）薄膜荧光光谱的反常温度依赖特性

可溶性聚（２，５－二丁基氧基苯）薄膜荧光光谱的反常温度依赖特性马於光，吴英，张海峰，田文晶，沈家骢，刘式墉，孙猛（吉林大学分子光谱与分子结构开放实验室，集成光电子学国家实验室，长春，１３００２３）（复旦大学高分子科学系）关键词聚（２，５－二丁基氧基苯...     

间位聚苯及其衍生物的构象与电子结构的理论研究

用分子力学方法(MM)对间位聚苯(PMP)及其衍生物的势能随扭曲角(f)变化规律进行了研究.结果表明，势能曲线上出现四个能量最小值，分别对应于扭曲角f ≈－135°,－45°,45°,135°.进一步对以上构建的全部PMP及其衍生物用分子力场Drieding 2.11进行了分子力学能量优化.最终得到主要的四种构象，其中螺旋构象的能量最低，而且以螺旋构象为优势分布构象.在真实条件下，PMP及其衍生物长链可能采取以上四种构象的混合片段组成.用量子化学方法(GGA-DFT)研究了PMP及其衍生物的电子结构能隙随相邻苯环之间的扭曲角的变化趋势.用量子化学半经验方法(AM1)对四种构象分别进行几何优化，优化结果与分子力学优化结果基本一致，并运用混合密度泛函方法(DFT/B3LYP/6-31G)进一步对AM1优化的构象结构进行更精确的电子结构能隙计算.最终得出影响间位聚苯及其衍生物电子结构能隙的主要因素为连接苯环间扭曲角的大小.