CM⁃Phos配体在钯催化交叉偶联反应中的应用

本文综合评述了近年来2-[2-(二环己膦基)苯基]-1-甲基-1H-吲哚(CM-Phos)膦配体及其衍生物在钯催化的交叉偶联反应中的应用, 主要根据不同种类的交叉偶联反应进行系统性分述, 并对该领域的发展前景进行了展望.     

一种蓝光发射星型有机分子的合成及光电性质

采用分子设计的思想,通过多步反应合成了一种新型的以N原子为中心的蓝光发射星型有机小分子。用1H NMR,MS和元素分析进行了表征,研究了化合物的热稳定性和真空镀膜膜层的光致发光性质,用循环伏安法测定了其电化学性能。结果表明,这种合成的有机化合物光致发光性能优良(量子效率达到87%),热稳定性好,可作为制作有机电致发光器件的候选材料。     

Structural Tracking of a Bimolecular Reaction in Solution by Time‐Resolved X‐Ray Scattering

Molecular movies : Time‐resolved X‐ray scattering provides direct structural information on an electronically excited complex while it is formed in the bimolecular reaction between excited octahydrogen[tetrakis‐μ‐diphosphito‐1κP:2κP′‐diplatinate](4‐) (PtPOP*) and thallium ions. In the exciplex one thallium(I) and two platinum(II) ions are found to be collinear.

     

“绿色”液体激光介质的非线性光学特性研究

 利用氧化钕和盐酸为原料制得Nd(phen)2Cl3(三氯二邻菲罗啉合钕),测得其光谱特性并以稀土氧化钕、苯甲酸和邻菲罗啉为原料制得绿色液体激光介质钕离子的配合物——NdB3phen（三苯甲酸—邻菲罗啉合钕）.利用飞秒激光器,采用单光束Z-扫描法研究了NdB3phen的三阶非线性光学特性.结果表明:当入射飞秒激光脉冲波长为400 nm,峰值功率密度为2.94×1014 W/m2,脉宽为117 fs时,测得样品NdB3phen的非线性折射率为－2.84×10－18 cm2/W|NdB3phen在开孔条件下呈现反饱和吸收现象,测出双光子吸收系数的值为9.11×10－12 m/W.实验结果表明,NdB3phen的双光子吸收系数和非线性折射率随着光强的增强而增大.     

Generalised twists, , and the p-energy over a space of measure preserving maps

Let be a bounded Lipschitz domain and consider the energy functional

with p]1,∞[ over the space of measure preserving maps

In this paper we introduce a class of maps referred to as generalised twists and examine them in connection with the Euler–Lagrange equations associated with over . The main result is a surprising discrepancy between even and odd dimensions. Here we show that in even dimensions the latter system of equations admit infinitely many smooth solutions, modulo isometries, amongst such maps. In odd dimensions this number reduces to one. The result relies on a careful analysis of the full versus the restricted Euler–Lagrange equations where a key ingredient is a necessary and sufficient condition for an associated vector field to be a gradient.     

Using FTIR spectroscopy to detect sericin on historic silk

Silks represent some of the most precious ancient and historic textile artefacts in collections worldwide.Their optimum preservation demands an appreciation of their characteristics.One important concern,especially with regard to ancient Chinese silks,is whether the fabrics have been degummed.Silks with remnant sericin gum coating the fibroin fibres would require different conservation protocol.In previous research on aged silks,the presence of sericin has been inferred from amino acid analysis of hydrolysa...     

含钒(IV)和钒(V)的钨锗混合价杂多酸盐的合成及其结构表征

报道了含钒(IV)和钒(V)的钨锗混合价杂多酸盐的合成、电子吸收光谱及单电子还原态的ESR谱。α-和β-[HGeV^I^VV2^VW9O40]^7^-的溶液ESR谱是由40余条超精细线组成的, 表明在阴离子中3个VO6八面体是角顶共用, 且其中一个桥氧原子是质子化的。     

The invariants of the non-degenerate representations of the group of the pseudo-orthogonal matrices SO (p, 1)

The invariants of the non-degenerate representations of the group of pseudo-orthogonal matrices SO(p, 1) are constructed.     

一种新型高速电影经纬仪

112高速电影经纬仪是一种新型的高速光电跟踪测量设备,可用于快速飞行目标的轨迹测量和姿态记录,单台完成定位,并有实时输出的功能。该设备与传统的电影经纬仪相比,具有明显的特点,它采用双反射镜跟踪的结构方式,减少了运动部分的惯量,并提高同步数据采集处理速率到200次/秒和高速同步摄影频率到200f/s,有利于高速跟踪测量。该设备采用电视跟踪、计算机程序控制、单杆操纵等多种跟踪方式,可根据不同的目标特性方便地选用或组合使用,可靠地完成对目标的自动捕获和跟踪测量,最大跟踪速度为90°/秒,最大跟踪加速度为90°/秒²。本文还介绍了该设备在靶场使用情况。     

Structural and magnetic dynamics of a laser induced phase transition in FeRh

We use time-resolved x-ray diffraction and magneto-optical Kerr effect to study the laser-induced antiferromagnetic to ferromagnetic phase transition in FeRh. The structural response is given by the nucleation of independent ferromagnetic domains (τ(1)~30 ps). This is significantly faster than the magnetic response (τ(2)~60 ps) given by the subsequent domain realignment. X-ray diffraction shows that the two phases coexist on short time scales and that the phase transition is limited by the speed of sound. A nucleation model describing both the structural and magnetic dynamics is presented.