Synthesis of New Chiral Phosphine Ligands and Their Application in Asymmetric Hydrogenation of Ketones

The design of new chiral ligands is the key in the development of transition metal catalyzed asymmetric synthesis. Many chiral diphosphine ligands have been prepared and applied in asymmetric catalytic reactions with excellent enantioselectivities. Among the chiral diphosphine ligands that have been reported, the atropisomeric C2-symmetric phosphines with a biaryl scaffold initiated by Noyori and co-workers with BINAP were found to have the widest application in the transition metal catalyze…     

一种含噻吩环酰腙及其Cu(Ⅱ)配合物的合成、晶体结构和抗氧化活性及量化计算

合成了一种酰腙类含硫Schiff碱4-(二乙胺基)水杨醛缩2-噻吩甲酰腙一水合物(H₂L·H₂O,1),采用扩散法制备了它的铜配合物[Cu(phen)L](2,phen=菲咯啉),通过元素分析、红外光谱、紫外光谱和X射线单晶衍射对它们进行了表征。1的晶体属正交晶系,P2₁2₁2空间群;2的晶体属单斜晶系,P2₁/c空间群。在2中H₂L以烯醇式脱除羟基质子与铜配位,中心离子的配位环境为畸变的四方锥构型。应用Gaussian 09程序,采用密度泛函方法(DFT),分别在B3LYP/6-31G(d)和UB3LYP/6-31G(d)水平对1和2进行了量化计算,对分子的前线分子轨道的能量和组成以及电子光谱进行了分析讨论。测试、分析了化合物的抗氧化活性。     

十二烷基磺酸钠微乳状液结构转变的电化学研究

制备了C12H25SO3Na-C4H9OH-C7H16-H2O四组分体系在km=W(C4H9OH)/W(C12H25SO3Na)=2时的拟三元相图。使用二茂铁和铁氰化钾作为电化学探针用循环伏安法测定了起始含油量为21％的无水混合物在滴加水过程中所形成的微太液的扩散系数。从扩散系数随含水量的变化确定微乳液的结构转变。含水量为20％－45％时生成油包水型微液;含水量大于65％时生成水包油型微乳液。当含水量在45％－65％之间时形成的是二连续型微乳液。电导率数据证实了循环伏安法的测定结果。     

Peak shape analysis of Ag 3d core‐level X‐ray photoelectron spectra of Au@Ag core‐shell nanoparticles using an asymmetric Gaussian–Lorentzian mixed function

This article reports on the peak shape analysis of X‐ray photoelectron spectra of gold‐silver core‐shell (Au@Ag) nanoparticles (NPs) using an asymmetric Gaussian–Lorentzian mixed function. Unlike Ag NPs, Au@Ag NPs have no oxide peak and show asymmetric line shape with a high energy tail in Ag 3d core‐level spectra. A monotonic increase in the Ag 3d binding energy and a decrease in the degree of asymmetry with increasing the Ag shell thickness were observed supporting the occurrence of charge transfer from Au core to Ag shell. Copyright © 2012 John Wiley & Sons, Ltd.     

基于高光谱反射率的冬小麦生长后期氮素丰度监测研究

生物量、氮素含量和LAI(leaf area index)是生态系统中表征作物长势最重要的参数,叶干重、叶片氮素含量和LAI实时动态监测对小麦氮素营养诊断和管理调控具有重要意义。选用了五个小麦品种和四个氮素水平的比较实验,研究不同处理冬小麦抽穗到黄熟期氮素丰度(NR)与光谱反射率差值(ΔR)的关系,建立冬小麦后期氮素丰度监测模型。结果表明,不同品种的冬小麦冠层叶片氮素丰度随生育进程推进而增加,不同氮素处理氮素丰度大小为N0N3N1N2,光谱参量TCARI和VD672与氮素丰度的相关性最好,相关系数(r)分别为0.870和0.855,其建立氮素丰度估测模型的决定系数分别为0.757和0.731,预测准确率达84.56%和80.13%。光谱参数TCARI和VD672可以有效地评价小麦后期冠层叶片氮素状况,可以对氮素丰度进行准确可靠的监测。     

Radiative leptonic decay B-c→τ-(v)τγ in the standard model and the two-Higgs-doublet model

We analyze the radiative leptonic Be decay B-→τ-(v)τγ in the Standard Model and the twoHiggs-doublet model using the non-relativistic constituent quark model.The results confirm that this channel is experimentally promising in view of the large number of Bc mesons which are expected to be produced at future hadron facilities.We also find that this decay is sensitive to the parameters of the two-Higgs-doublet model,and it can be tested in future experiments.     

丙三醇/水混合溶剂中CTAC/NaSal胶束体系粘度的研究

本文研究了丙三醇/水混合溶剂中十六烷基三甲基氯化铵(CTAC)溶液的粘度性质,考察了水杨酸钠(NaSal)浓度、CTAC浓度以及丙三醇体积分数等因素对CTAC胶束溶液粘度的影响,并与乙二醇/水混合溶剂中胶束的粘度进行比较。结果表明:在丙三醇/水混合溶剂中,当CTAC浓度一定时,CTAC溶液的相对粘度随着NaSal浓度的增大而增大;当NaSal浓度一定时,CTAC溶液的相对粘度随着CTAC浓度的增大出现最大值;CTAC溶液的相对粘度随着丙三醇体积分数的增大而下降。这种变化趋势与乙二醇/水混合溶剂中的粘度性质相类似。     

Microporous Zinc Formate for Efficient Separation of Acetylene over Carbon Dioxide

Separation of acetylene(C₂H₂) from carbon dioxide(CO₂) by adsorbents is very challenging owing to their high similarity on molecular shape and dimension. Exploring inexpensive and easily available porous materials is of importance to facilitate the practical implementation of the challenging but energy-efficient separation. Herein, we utilize an easily available porous material[Zn₃(HCOO)₆] for the selective separation of C₂H₂ over CO₂. Because of the pore confinement in[Zn₃(HCOO)₆](pore size of 0.47 nm) and accessible oxygen sites for preferential binding of C₂H₂, this material exhibits high low-pressure uptake for C₂H₂(63 cm³/cm³ at 10 kPa and 298 K) and high C₂H₂/CO₂ selectivity(7.4 under ambient conditions) that is comparable to those of out-performing porous materials. The efficient separation of[Zn₃(HCOO)₆] for C₂H₂/CO₂ mixture has also been confirmed by the breakthrough experiments.     

Chemical Constituents of the Leaves of Artocarpus integer

Chemistry of Natural Compounds -     

用于高性能锂硫电池的二维氮硫共掺杂多孔碳纳米片的快速合成

本工作基于工业炼油产品沥青,开发了一种无金属、氮和硫共掺杂多孔碳纳米片（NSPC）的合成方法。获得的多孔碳纳米片具有高比表面积（339 m²·g^-1）和优异的固硫能力。同时,高含量氮、硫共掺杂可以有效增强碳材料的导电性,同时促进多硫化物的高效催化转化。通过熔融法固硫后,制备得到的NSPC/S电极具有较高的比容量和优异的循环稳定性（在0.6C电流密度下,200次循环后容量为762 mAh·g^-1）,实现了高含量氮和硫共掺杂的二维多孔碳材料的快速批量生产并用于高性能锂硫电池正极材料。