通过硼氢化-原位再结晶提高二异松莰烷基硼烷光学纯度的简便方法

本文叙述了由国产低光学纯(43.6%e e)(-)-α-蒎烯通过硼氢化-原位再结晶, 制备高光学纯(97.2%ee)(+)-二异松茨烷基硼烷(diisopinocampheylborane, Ipc2BH)的简便新方法。     

诺氟沙星–铜(Ⅱ)-吡啶衍生物配合物的合成、表征及生物活性

诺氟沙星(NFA)(图1)(1-乙基-6-氟-1,4-二氢-4-氧代-7-(1-哌嗪基)-3-喹啉羧酸)是一种典型的喹诺酮类抗菌化合物,主要通过抑制DNA旋转酶和拓扑异构酶Ⅱ使脱氧核糖核酸、核糖核酸及蛋白质的合成受到干扰,使细胞不能再进行分裂,而起杀菌作用,具有广谱抗菌性[1].     

动脉中非平稳流动壁面剪切力及其Hilbert-Huang变换

本文通过数值方法求解均匀动脉中的非平稳脉动流,给出了通过测量非平稳脉动血流量确定壁面切应力的方法.作为算例,采用实测的大鼠颈总动脉流量信号,求出了均匀动脉壁面切应力波形.进一步对求得的切应力波形进行经验模态分解(EMD),得到了切应力波形的各内在模态(IMF),以及Hilbert幅值谱.从切应力波形经Hilbert-Huang变换得到的IMF和Hilbert谱图可以明显地看出切应力各频率成分的物理意义.所得结果为进一步深入研究非平稳脉动切应力与血管重建的关系提供了一种方法学基础.     

电化学分析法在铬形态分析中应用进展

对近年来电化学分析法应用于铬的形态分析的现状和发展趋势进行了概述。     

Suzuki Reaction of Aryl Bromides Using a Phosphine-Free Magnetic Nanoparticle-Supported Palladium Catalyst

A palladium catalyst immobilized on superparaganetic nanoparticles was prepared with a palladium loading of 0.30 mmol/g. The catalyst was characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometry, thermogravimetric analysis, Fourier transform infrared, atomic absorption spectrophotometry, and nitrogen adsorption. The immobilized palladium catalyst was an efficient catalyst without added phosphine ligands for the Suzuki cross-coupling reaction of several aryl bromides with phenylboronic acid. The recovery of catalyst was simply by magnetic decantation in the presence of a magnet. The immobilized palladium catalyst can be reused many times without significant degradation in catalytic activity. No leaching of active palladium species into the reaction solution was detected.     

1,10-邻菲咯啉-铜(Ⅱ)-L-丝氨酸/L-酪氨酸配合物的合成、SOD活性及电化学性质

合成了两个新的配合物:[Cu(Phen)(L-Ser)(H2O)]Cl(1)和[Cu(Phen)(L-Tyr)(H2O)]Cl.2H2O(2)(Phen=1,10-邻菲咯啉、L-Ser=L-丝氨酸、-LTyr=L-酪氨酸).用元素分析、摩尔电导率、红外光谱、紫外-可见光谱对配合物进行了表征.分别采用NBT光还原法和循环伏安法测定了配合物的SOD活性及电化学性质.结果表明,这些配合物具有较高的SOD活性,配合物1、2催化O2-.歧化分解速率常数KQ值分别为3.16×107和1.54×107mol-1.L.s-1.     

水基切伦科夫μ子探测器的研究

利用高速带电粒子在透明介质中产生切伦科夫辐射的特性,以蒸馏水作为辐射介质,搭建了一个小尺寸(π×22.52cm2×45 cm)的切伦科夫探测器,对能量在GeV量级的μ子进行了相应的测量,考虑其他能量损耗、光传输和收集效率、阴极量子效率后,实验结果与理论估计值有比较高的相符度,可以初步断定仪器具备探测GeV量级μ子的能力.     

A NOTE ON SINGULAR INTEGRALS WITH DOMINATING MIXED SMOOTHNESS IN TRIEBEL-LIZORKIN SPACES

Let h be a measurable function defined on R+×R+. LetΩ∈ L(log L+)νq(Sn1-1×Sn2-1)(1 ≤νq≤ 2) be homogeneous of degree zero and satisfy certain cancellation conditions. We show that the singular integral T f(x1, x2) = p. v.∫ Rn1+n2Ω(y′1, y′2)h(|y1|, |y2|)|y1|n1|y2|n2f(x1- y1, x2- y2)dy1dy2maps from Sα1, α2p, q˙F(Rn1× Rn2) boundedly to itself for 1 p, q ∞, α1, α2 ∈ R.