A New Method to Investigate the Clustering Phenomena in Supercritical Fluids

EstimationoflocaldensityofsolventaboutthesoluteSolvatochromicbehaviorsofspectroscopicprobesarewidelyusedtoestimatethesol-ventstrengthofsupercriticalfluids(SCF,).i-3lnthiswork,thesolvatochrondcshiftofthen-n*transitionbandforacetone(O.o37mo1.L-')insupercrihcal(SC)CO2wasde-terminedbyUVspectroscopytostUdythesolvationeffect.TheMcRae-BaylissexpressionbasedonthedielectriccontinUUInmodelgivestherelahonshipbetWeenso1vatochromicshiftandpo1arizabilityofnonPolarsolvents4-5asfollows:wherevisthewave…     

特征线法在求解非线性液相吸附色谱模型中的应用

本文应用特征线法求解非线性液相吸附色谱分离过程模型，论述了特征线法的原理和步骤，讨论了时间步长和空间步长对模型数值解的影响，并用色谱分离甘露醇和山梨醇以及分离蔗糖和还原糖的实验进行验证，用特征线法计算的理论流出曲线与实验流出线吻合较好。本文还分折了模型中各个参数的灵敏度，结果表明：吸附等温方程Q＝Ci*／（ai＋biCi*）中参数ai比参数bi以及总传质系数ki有更高的灵敏度。     

Cover Picture: Highly Regioselective Sequential 1,1‐Dihydrosilylation of Terminal Aliphatic Alkynes with Primary Silanes (Chin. J. Chem. 5/2019)

The cover picture shows that sequential 1,1‐dihydrosilylation of terminal aliphatic alkynes with primary silanes enabled by one earth‐abundant cobalt catalyst has been developed. This protocol is operationally simple using readily available aliphatic alkynes, including simple acetylene and complex drug derivative, for efficient access to valuable gem‐bis(dihydrosilyl)alkanes in highly regioselective and atom‐economic manners. Corresponding asymmetric transformations are achieved with excellent enantioselectivities. More details are discussed in the article by Lu et al. on page 457–461.

     

The Reaction and Applied Study of the Amide and P_2S_5

It is usually reported that reaction between carbonyl and P2S5 produce thiono group compound. The Products from carbonyl after ammonolysis and hydrazinolysis have the very import applied value in the synthesize of heterocyclic compound. Sulfuration reation if a nucleophilic attack, SPS2 anionsid obtained from P2S5 in the organic sovent, rather easier than thereationsof scheeren’s reagent. The reation mechanism is as follows: The reation speed has something todo with the electronegative of…     

Simple and controllable synthesis of highly dispersed Pt-Ru/C catalysts by a two-step spray pyrolysis process

A carbon supported Pt-Ru catalyst with uniform distribution and small average size of the Pt-Ru particles was synthesized using a two-step spray pyrolysis (SP) method; the electrocatalytic activity of the prepared catalyst for methanol oxidation is better than that of the standard commercial catalyst.     

二吡啶四硝基酞菁钴的合成及光谱—电化学性质研究

本文报道了以钼酸铵为催化剂,将4—硝基邻苯二甲酸酐、脲和氯化铵混合,于220℃加热合成四硝基酞菁钴,将此配合物溶于吡啶,于115℃加热反应6天合成了二吡啶四硝基酞菁钻配合物。并对二吡啶四硝基酞菁钴的氧化还原半波电势、电解氧化还原产物的电子吸收光谱进行了研究。     

由NO分子从头计算结果和紫外光电子能谱确定NO的分子结构

对于NO分子轨道的能级次序现有两种不同的说法,不少人根据NO与O_2~+是等电子体,由O_2~+分子的能级次序确定NO分子组态。本文用NO和O_2~(+)从头计算结果以及NO的紫外光电子能谱相结合的方法说明NO的5σ轨道是弱成键轨道,5σ的轨道能稍高于1π轨道能,也就是说NO的能级次序是与N_2分子相同的;NO与O_2~+虽是等电子体,但是能级次序并不相同,因此由O_2~+的能级次序确定NO分子的电子组态是不妥的。     

Preparation of Co3O4 Nanofibers via an Electrospinning Technique

Thin PVA/cobalt acetate composite fibers were prepared by using sol-gel processing and electrospinning technique.After calcination of the above precursor fibers,Co3O4 nanofibers with a diameter of 50-150 nm could be successfully obtained.The fibers were characterized by SEM,FT-IR,WAXD,respectively.     

软刻蚀及其应用

软刻蚀是一类基于自组装和复制模塑等原理的非光刻微米和纳米加工方法。它为形成和制作微米、纳米图案提供了简便、有效、价廉的途径。在软刻蚀中，用一个表面带图案的弹性模板来实现图案的转移，其加工的分辨率可达30nm－100μm。软刻蚀是微接触印刷、复制模塑、转移微模塑、毛细微模塑、溶剂辅助微模塑等的总称。本文将简介软刻蚀的原理、方法以及它们在微米和纳米加工、微电子学、材料科学、光学、微电子机械系统、表面化学等方面的应用。     

改性环糊精气相色谱手性固定相拆分对映体的选择性及拆分机理的讨论

改性环糊精气相色谱手性固定相拆分对映体的选择性及拆分机理的讨论周昕，万宏，欧庆瑜（中国科学院兰州化学物理研究所兰州７３００００）１前言自１９８８年Ｋｏｎｉｇ￣［１］等人成功地将改性环糊精用于毛细管气相色谱固定相拆分对映体以来，环糊精衍生物以其高选择性...