Luminescence of the compounds Y0.5-xLi1.5VO4 :(Dy3+,Eu3+)

In this paper for the first time the compounds Y0.5-xLi1.5VO4:(Dy3+, Eu3+),(YLV:Dy,Eu) (0.01

Luminescent self-assembled thin films based on rare earth-heteropolytungstate

earth (Eu3+, Dy3+)-heteropolytungstate thin films were fabricated by self-assembly method successfully. The thin films give off strong fluorescence, which can be observed by eyes upon UV irradiation. The characteristic emission behaviors of the rare earth ions in self-assembled thin film were investigated compared with those of the corresponding solids. It is noticed that the intensity ratio between D-5(0) --> F-7(2) and D-5(0) --> F-7(1) of Eu3+ and the intensity ratio between F-4(9/2) --> H-6(13/2) and F-4(9/2) --> H-6(15/2) of Dy3+ in the self-assembled films are different from those of the corresponding solids. Furthermore, the self-assembled films present shorter fluorescence lifetimes than the corresponding solids. The reasons for these results have been discussed.

Real-time analysis of the interaction between calmodulin and melittin by SPR spectroscopy

The dynamic interaction process of calmodulin with an immobilized peptide melittin was investigated in real time by surface plasmon resonance spectroscopy, and dissociation constant of the complex was calculated to be 3.37 x 10(-6) mol/L.

YAG∶Nd中Pr,Sm,Dy杂质对其光谱的影响

采用溶胶 -凝胶法合成了YAG∶Nd ,Re(Re =Pr,Sm ,Dy)系列化合物 ,研究了它们的光谱性质 .结果表明 :Pr3 + ,Sm3 + ,Dy3 + 对YAG基质中Nd3 + 的发光具有猝灭作用 ,属于有害杂质 ,在激光晶体原料中必须除去

镧对小鼠肝脏中几种酶活性的影响

分别从体内作用和体外作用两个方面研究了镧对鼠肝脏中的胆碱脂酶、异柠檬酸脱氢酶、谷丙转氨酶活性的影响 ,同时用电感耦合等离子质谱 (ICP -MS)研究了镧在肝脏中的累积情况 .结果表明 :经尾静脉注射后镧在肝脏中有明显的累积现象 ,其累积量随给药剂量的增大而增加 ;镧对上述三种酶的活性均表现出低剂量激活 ,高剂量抑制的Hormesis效应

用荧光光谱和紫外-可见差谱研究抗体-卟啉的相互作用

meso-四 (α,α,α,α-O-苯乙酰苯 )卟啉与其单克隆抗体 1 F2结合后 ,产生显著的增色效应 ,反映了卟啉与抗体之间刚性紧密的结合 ,在抗体中的抗原结合部位存在芳香族氨基酸 .用同步荧光光谱结合荧光猝灭法得到抗体抗原结合部位的芳香族氨基酸主要为色氨酸和酪氨酸 ,但酪氨酸的残基数要少于色氨酸 .卟啉与抗体的结合比为 1∶ 1 ,解离常数 (2 .0 84± 0 .2 46)× 1 0 - 1 0 mol/L,可见卟啉与 Mc Ab1 F2有很高的亲和力.

高分子化铁系烯烃聚合催化剂的合成及乙烯聚合

合成了含烯丙基不对称型的“茂后”催化剂[ArN=C（Me）][Ar’N=C（Me）]C5H3NFeCl2[Ar=2,6-（i-Pr）2C6H3,Ar’=4-烯丙基-2,6-（i-Pr）2C6H3],通过IR,1H NMR,EI-MS,EA对化合物进行表征.利用这个催化剂上的烯烃基团在自由基引发下与苯乙烯共聚,制备出高分子化的“茂后”催化剂.研究了高分子化前后催化剂催化乙烯聚合行为,高分子化的催化剂在常压13℃下催化乙烯聚合时,活性最高达到2.5×106g PE/mol Fe·h,高于未高分子化之前催化剂的活性.证明了高分子化是“茂后”催化剂理想的固载化方式.

环丙烷衍生物在D_2O离子体系中的H/D交换反应

在Ｄ_２Ｏ化学反应气条件下研究了环丙烷衍生物的Ｈ／Ｄ交换反应特性。发现了三种新的 产物离子［Ｍ＋１］~＋、［Ｍ＋２］~＋和［Ｍ＋３］~＋．应用碰撞诱导碎裂（ＣＩＤ）技术研究了这些离子的碎裂反应 特性。实验结果表明三种新的产物离子是由反应物与试剂离子之间发生Ｈ／Ｄ交换反应生成的。并 获得了环丙烷衍生物结构中活泼氢位置及其数量的信息。

Selective crystallization of BaF2 under a compressed Langmuir monolayer of behenic acid

Selective crystallization of BaF2 crystals under a compressed Langmuir monolayer of behenic acid [CH3(CH2)(20)COOH] has been studied by using X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and energy-dispersive X-ray analysis. It was found that, in the absence of a monolayer, three kinds of crystals (Ba2ClF3, BaClF, and BaF2) can be obtained by mixing BaCl2 with a NH4F solution. However, in the presence of the monolayer of behenic acid, only BaF2 crystals appear at the monolayer-subphase interface and crystals have a special crystal face (100). During this process of crystallization, the monolayer plays a very important role and acts as a template that can preferentially select a special crystal and a special crystal face. The above results can be explained in terms of a specific molecular interaction between ions and the headgroups of the monolayer and specific electrostatic, geometric, and stereochemical interactions at the organic-inorganic interface.

纳米发光材料研究的若干进展

本文综述了纳米发光材料的研究进展情况 ,着重总结了 (稀土 )掺杂型纳米发光材料的制备方法和表征手段 ,同时介绍了这些纳米发光材料的性质和应用 ,并对其未来发展趋势进行了展望。

聚合物电解质的玻璃化转变温度与离子解离的关系

采用动态力学和数学拟合相结合的方法 ,研究了聚环氧乙烷环氧丙烷—LiClO4 体系的离子解离与缔合。结果表明 :Tg的增加依赖于盐浓度和环氧乙烷 (EO)与环氧丙烷 (PO)的比例 ,并且玻璃化转变温度 (Tg)的增加可以用一个简单的溶解平衡解释 ,进而得出平衡常数K和离解度α

Synthesis and properties of cerium oxide nanometer powders by pyrolysis of amorphous citrate

CeO2 nanometer powders of different sizes were prepared at low temperature by pyrolysis of amorphous citrate. XRD patterns show that CeO2 is cubic in structure, space group O-h(5)-F-M3M. TEM indicates that the prepared CeO2 is spherical in shape, and the particle size distribution is in narrow range. It was found that calcination temperature is a more important factor affecting the crystallite size of CeO2 than calcining time, the smaller the particle, the bigger the crystal lattice distortion, the worse the crystal growth. Solubility test of CeO2 in nitric acid reveals that the surface activity of CeO2 decreases with the increasing particle sizes. IR spectra analysis shows that the absorption of Ce-O bond is shifted to higher energy with the decrease of CeO2 particle sizes.

PA1010结晶的异相成核作用研究

通过引入成核剂（Ｎｄ２Ｏ３）研究ＰＡ１０１０微晶结构的变化，以及对ＰＡ１０１０结晶行为的影响，也讨论了成核剂对结晶－非晶中间相的作用。利用ＷＡＸＤ，ＳＡＸＳ和ＤＳＣ手段，讨论了成核剂的异相成核作用。结果表明，成核剂明显改变了ＰＡ１０１０的微晶结构。

含对羟基苯甲酸、对苯二甲酸、间苯二酚、4,4′-二羟二苯酮共聚酯的流变行为研究

采用锥板流变仪研究了本实验室合成的含对羟基苯甲酸、对苯二甲酸、间苯二酚、４，４′－二羟二苯酮共聚酯的流变行为，结果表明，该共聚物具有典型的热致液晶性聚合物的流变特性。

希土与L-甲状腺素(T4)相互作用的研究

在二甲亚砜水混合溶剂中用ｐＨ电位法测定了Ｔ４的质子化常数以及与五种希土离子（Ｐｒ３＋、Ｅｕ３＋、Ｇｄ３＋、Ｔｂ３＋、Ｙｂ３＋）生成配合物的稳定常数。体系中主要生成１１０型配合物，紫外吸收光谱，ＨＮＭＲ表明，在较低ｐＨ值，Ｔ４通过羧基与希土配位，ｐＨ较高时，氨基也相继配位。配位键以离子性为主，荧光光谱表明，Ｔ４对中心希土离子的荧光有猝灭作用。