基于小波变换的多频静电力显微镜动态过程测量方法

静电力显微镜(electrostatic force microscopy,EFM)具有较高的灵敏度和空间分辨率,在新能源材料静电性质的测量中被广泛应用.时间分辨静电力显微镜技术主要用于材料的动态电学性质测量,该技术中常用的泵浦探测方法存在设备装置复杂、成本昂贵、测量存在不确定性等问题.本文采用直接时域测量方法,减小了测量的实现复杂度,通过应用多频激励或者激励悬臂高阶模态的方法实现了EFM多种参数同时测量和时间分辨率的提高,达到了微秒级的时间分辨率,并应用小波变换对测量得到的探针信号进行分析,实现了对材料动态电学性质的提取.通过应用该技术进行仿真实验,实现了对模拟样品电势衰减过程中的动态电势变化和模拟电池放电过程中的离子运动特征时间等性质的测量.     

Exogenous bridge and tautomer effects on magnetic interaction of binuclear copper(II) complexes of μ-phenolato Schiff bases

Four enol-form binuclear copper complexes with different exogenous bridges, [Cu2(L)(μ-Cl)] (1), [Cu(L)(μ-N3)]· DMF (2), [Cu2(L)(μ-OCH3)] (3) and [Cu2(L)(μ-C3H3N2)]· 1/2C2H5OH (4), where L is the trivalence anion of binucleating ligand 2,6-diformyl-4-methylphenol di(tenzoylhydrazone), have been synthesized and characterized. Crystal data for complex (3) are as follows: space group P1- , a=0.8294(1), 6=0.9333(3), c= 1.473 6(6) nm, α=79.51(3)°, β=80.93(2)°,γ=81.32(2)°, Z=1. The magnetic measurements indicated that the effect of exogenous bridging ligands on magnetic interaction is corresponding to that in spectrochemical series. The effect of enol- and keto-form tautomer on magnetic interaction was explained from the point of view of structural factors and electron effects by using molecular mechanks and quantum chemistry calculations.     

磷酸酯桥联和端基配位的双核铁(Ⅲ)配合物

为了模拟氧化型紫色酸性磷酸酶的活性中心 ,合成出一个分子式为 [Fe2 (HPTB) {μ O2 P(OPh) 2 }{O2 P(OPh) 2 }2 ](ClO4) 2 ,(HPTB =N ,N ,N′,N′ 四双 ( 2 苯并咪唑甲基 ) 2 羟基 1 ,3 二胺丙烷 )的双核铁的配合物 .晶体结构分析表明 ,配合物分子中双核铁 (Ⅲ )被一个来自配体的烷氧基和一个双齿配位的磷酸二苯酯桥联 ,同时2个单齿配位的磷酸二苯酯分别与一个铁离子配位 .2个铁离子均为六配位的畸变八面体几何构型 .晶体学数据 :三斜晶系 ,P1空间群 ,a =1 .5 1 2 1 3( 5 )nm ,b =1 5 91 1 9( 5 )nm ,c =1 .890 90 ( 5 )nm .α =6 9.92 5 ( 1 )° ,β =84.35 8( 1 )° ,γ =6 5 .71 2 ( 1 )°,Z =2 .研究了配合物的电子吸收光谱 ,1HNMR和磁性     

钆类造影剂的研究进展

从钆螯合物造影剂的原理、条件、研究进展、以及提高其弛豫效率的方法4个方面进行介绍与总结;在研究进展方面,着重介绍了荧光、生物敏感造影剂;并且从酶活性、金属离子活性、pH活性3个方面对生物敏感造影剂进行了论述。     

弹性约束边界条件下拉索结构横向振动特性分析

在拉索两端引入线性约束弹簧和扭转约束弹簧,通过对弹簧设置相应的刚度系数,得到弹性边界条件包括经典边界条件下的拉索横向振动模型.振动位移采用切比雪夫级数展开,使得横向位移在整个求解域内足够光滑.对不同边界条件下的拉索横向振动进行了研究,研究结果与参考结果的良好吻合验证了所构造模型的正确性;并进一步对线性约束弹簧刚度和扭转约束弹簧刚度对拉索横向振动特性的影响进行了分析.研究结果表明,边界条件对拉索振动固有频率的影响不可忽略.     

蜻蜓飞行姿态的实时模拟测量

作为昆虫自由飞行姿态实时测量的预研课题，本文利用投影栅线法对真实蜻蜓翅膀在适当频率摆动的机械驱动下模拟真实飞行时的三维形状变化进行了实时测量，由于在图像采集，预处理，位相提取，抑噪声去包络等环节采取了一系列措施，克服了由于蜻蜓翅膀透明度高，表面微观起伏变化剧烈所导致的栅线条纹图的平均灰度、对比度和信噪比都很低而给数据处理带来的困难，并最终得到了满意的结果。     

VISCOELASTIC CONSTITUTIVE MODEL RELATED TO DEFORMATION OF INSECT WING UNDER LOADING IN FLAPPING MOTION

Flexible insect wings deform passively under the periodic loading during napping flight. The wing flexibility is considered as one of the specific mechanisms on improving insect flight performance. The constitutive relation of the insect wing material plays a key role on the wing deformation, but has not been clearly understood yet. A viscoelastic constitutive relation model was established based on the stress relaxation experiment of a dragonfly wing (in vitro). This model was examined by the finite element analysis of the dynamic deformation response for a model insect wing under the action of the periodical inertial force in flapping. It is revealed that the viscoelastic constitutive relation is rational to characterize the biomaterial property of insect wings in contrast to the elastic one. The amplitude and form of the passive viscoelastic deformation of the wing is evidently dependent on the viscous parameters in the constitutive relation.     

氰根桥连的锰钴五核配合物的合成与晶体结构

Reaction of [Mn(bpm)₂]²⁺ with K₃[Co(CN)₅(NO)] produces a cyano-bridged bimetallic compound,{[Mn(bpm)₂]_1.5[Co(CN)₅(NO)]}·2H₂O (1), (bpm=bis(1-pyrazol)methane). Compound 1 crystallizes in the tetragonal space group P4₃2₁2 with a=1.305 08(8) nm, b=1.305 08(8) nm, c=4.386 7(5) nm, V=7.471 5(10) nm³, and Z=8. Complex 1 exhibited a structure of a pentanuclear cluster. The Mn²⁺ ions each are surrounded by bpm ligands, forming the [Mn(bpm)₂]²⁺ cation fragment. Three cation fragments are connected to the two anion fragments, [Co(CN)₅(NO)]^3-, by cyanide bridges. The five metal ions form a trigonal bipyramidal structure, where the Mn²⁺ ions are situated in the equatorial plane and the Co²⁺ ions are on both sides of the plane. As a semirigid ligand, bpm is more flexible than rigid 2,2′-bipydine, and it results in the two different configurations in the [Mn(bpm)₂]²⁺ cation fragment. CCDC: 635764.     

对化学的挑战——分子铁磁体的设计

寻求常温下的分子铁磁体是自然界向化学家挑战的一个热点课题.本文介绍了迄今美、俄、法、日等国家在该领域已取得的最新成果及已采用的几种设计与合成途径,即有机方法、金属有机方法、金属—自由基方法和无机方法等.其中通过无机方法制得的铜锰交替链状配合物的铁磁相转变温度(T_c)达到30K,这是目前通过各种方法制得的T_c最高的分子铁磁体。     

2, 6─二甲酸─4─取代苯酚双缩苯甲酰肼双核铜(Ⅱ)配合物的合成与磁性

本文合成并表征了两个新的双核铜（Ⅱ）配合物：［Ｃｕ２（Ｌ）（μ－Ｃｌ）Ｃｌ２］，配体Ｌ为２，６－二甲酰－４－基苯酚双缩苯甲酰肼，取代基分别为氯（Ｌ１）和叔丁基（Ｌ２）。配合物具有相同的组成和配位构型。变温磁化率测定结果表明，由于取代基不同，其磁交换参数分别为－４６．２ｃｍ＾－１（Ｌ１）和－５７．６ｃｍ＾－１（Ｌ２）。