The Preparation of Cu(II)- and Ag(I)-responsive Carbon Nanodots from the Right Amino-acid Carbon Source

Journal of Fluorescence - Carbon nanodots (CDs) have exhibited excellent sensing capability for various metal ions. However, it is difficult to determine the selectivity of CDs to metal ions. In...     

A New Quantum Payment Protocol Based on a Set of Local Indistinguishable Orthogonal Product States

International Journal of Theoretical Physics - In this paper, a quantum payment protocol based on a special set of local indistinguishable orthogonal product states (X-LIOP) is proposed. In the...     

激光二极管触发光导开关实验研究

介绍了利用大功率半导体激光二极管触发3 mm间隙GaAs光导开关、产生非线性电脉冲输出的实验,激光二极管输出功率为70 W,上升前沿约20 ns,脉冲半高宽（FWHM）约40 ns。随着开关两端偏置场强增加,输出电压也线性增加,当偏置场强超过一定阈值,增至约2.53 kV/mm时,经过一个较小的电压峰值和时间延迟后,输出电压急剧增加,产生雪崩现象。实验结果表明:GaAs开关非线性输出的产生与载流子聚集和碰撞电离有关,偏置电场的提高增加了开关芯片中载流子聚集数量,加剧了碰撞离化程度,从而使开关从线性模式进入雪崩模式。     

激光冲击波对5B05铝合金表面应力状态的调整

采用X射线衍射仪分别对光斑中心及其边界点冲击前后3个方向上的残余应力进行测量。根据主应力及其方向角的计算公式,计算出了各测试点冲击前后的主应力值和主应力方向角,分析了其分布特性。结果表明,激光冲击波不仅能调整5B05铝合金表面残余主应力值,还能调整其方向。最大主应力增幅最大点与最小主应力增幅最大点并不在同一点上。5B05铝合金经激光冲击波作用后,表面应力状态得到了改善,应力分布变得分散,应力域变大。     

ZnSe、ZnS量子点的可控合成与表征

采用改进后的合成方法,以Se和ZnO粉末为原料,在十六胺(HDA)、月桂酸(LA)和三辛基膦(TOP)有机溶剂体系中合成了胶体ZnSe和ZnS量子点。主要研究了溶剂配比、反应温度及生长时间对ZnSe量子点粒径和光学性质的影响。结果表明:制得的ZnSe和ZnS量子点均是纤锌矿型结构,且具有较好的尺寸均匀性、分散性及荧光特性。粒子直径可控制在4.5~8 nm范围内。采用参数n(ZnO) : n(HDA) : n(LA)=1 : 2.1 : 5.2,c(TOPSe)=1 mol/L,在280 ℃成核,240 ℃生长条件下合成的ZnSe量子点具有最佳的尺寸范围,并且随着生长时间的延长,粒径变大,荧光发射峰明显红移。     

中空纤维脂质体微筛选及其用于中药中香豆素类和木脂素类可透膜成分群的筛选和捕获

建立了中空纤维脂质体微筛选(Hollow fiber liposome microscreening,HFLMS)研究中药透膜化合物的方法。以中空纤维为脂质体载体,在模拟人体自然吸收的条件下,对中药提取液中可透膜化合物进行了筛选,并用HPLC进行分析。本研究在对空白和脂质体中空纤维表面性质表征的基础上,对中空纤维活性中心与目标物的非特异性结合和HFLMS方法的重现性进行了考察;将HFLMS与HPLC结合,分别对中药材蛇床子、补骨脂、羌活、独活提取液中透过脂质体的香豆素类成分群和五味子提取液中透过脂质体的木脂素类成分群进行了筛选和捕获;通过与对照品的色谱保留时间比对,对筛选出的与脂质体结合的部分化合物进行了结构鉴别。     

溶胶凝胶法合成LiCuVO4及其电化学性能研究

以CH3COOLi.2H2O、Cu(NO3)2.3H2O、V2O5和双氧水(30%)为原料,采用溶胶凝胶法合成了LiCuVO4,其结构、组成和形貌经XRD和SEM确认。结果表明,本文所合成的LiCuVO4具有隧道结构的形貌,颗粒粒径为0.2～6μm。将LiCuVO4作为锂离子电池正极材料,首次循环的放电比容量达到160mAh/g;而作为负极材料,其最大放电比容量达到481mAh/g。在两种电化学测试中,LiCuVO4都显示了良好的循环性能。     

β‐Diketiminatoytterbium aryloxides: synthesis,structural characterization,and catalytic activity for addition of amines to carbodiimides

The steric effect of an aryloxido group on the synthesis and molecular structures of ytterbium aryloxides supported by β‐diketiminato ligand L (L = [N(2,6‐Me₂C₆H₃)C(Me)]₂CH^?) is reported. Reactions of β‐diketiminatoytterbium dichloride, LYbCl₂(THF)₂, with NaOAr¹ in THF (Ar¹ = [2,6‐^tBu₂‐4‐MeC₆H₂], THF = tetrahydrofuran) at 60°C gave the corresponding ytterbium complexes LYb(OAr¹)Cl(THF) ( 1 ) and LYb(OAr¹)₂ (1), depending on the molar ratio of dichloride to sodium aryloxide, respectively, while the same reactions with NaOAr² and NaOAr³ (Ar² = [2,6‐ⁱPr₂C₆H₃], Ar³ = [2,6‐Me₂C₆H₃]) in 1:1 or 1:2 molar ratio in THF afforded only bisaryloxide complexes LYb(OAr²)₂(THF) (1) and LYb(OAr³)₂(THF) ( 4 ) in good yields, respectively. Complexes 1 , 2 , 3 , 4 were fully characterized, including X‐ray crystal structure analyses. All the complexes are efficient pre‐catalysts for the catalytic addition of amines to carbodiimides giving guanidines. Copyright © 2013 John Wiley & Sons, Ltd.