Compressibility of a zinc single crystal under confining pressure

Abstract

In the present study, the two compressibility moduli of a zinc single crystal were measured at room temperature up to 18 GPa. The results are compared with those obtained by Bridgman from a different experimental method. This study required a gaseous hydrostatic confining pressure, and then it has been necessary to develop an original diamond anvil cell with a large optical aperture allowing the use of sophisticated video imaging and image analysis techniques. A model is proposed for the zinc volume-pressure relation.     

Synthesis of Carbohydrate Derived α-Methylene-γ-lactones by Diasterecseldctive,Low Temperature Reformatsky-Type Reactions

Hexopyranoside- and hexofuranose uloses with either ethyl 2-(branamethyl)acrylate in the presence of laminar Zn/Ag-graphite or ethyl 2-(trimethylsilylinethyl)acrylate/tetra-n-butylanrnonium fluoride undergo stereoselective branching, mainly with formation of spiro α-methylene-γ-lactones.     

Equilibrium Studies on Reactive Extraction of α-Cyclohexylmandelic Enantiomers Using Hydrophilic β-Cyclodextrin Derivatives Extractants

β‐Cyclodextrin (β‐CD) is negligibly soluble in organic liquids and can be modified to achieve a higher solubility in water. In this paper, racemic α‐cyclohexyl‐mandelic acid (α‐CHMA) was separated by chiral reactive extraction with aqueous β‐cyclodextrin derivatives. Hydroxypropyl‐β‐cyclodextrin (HP‐β‐CD), hydroxyethyl‐β‐cyclodextrin (HE‐β‐CD), and methyl‐β‐cyclodextrin (Me‐β‐CD) were selected as chiral selectors for reactive extraction of α‐CHMA enantiomers from organic phase to aqueous phase. Factors affecting the extraction efficiency were investigated, including the types of organic solvents and β‐CD derivatives, the concentrations of the chiral selector and α‐CHMA enantiomers, pH and temperature. The experimental results demonstrate that HP‐β‐CD, HE‐β‐CD, and Me‐β‐CD have stronger recognition abilities for S‐α‐CHMA than for R‐α‐CHMA. Among the three derivatives, HP‐β‐CD shows the strongest separation factor for α‐CHMA enantiomers. A high enantioseparation efficiency with a maximum separation factor (α) of 2.02 is observed at pH 2.5 and 5°C.     

Efficient aerobic oxidative dehydrogenation of dihydropyrimidinones and dihydropyrimidines

4-Substituted dihydropyrimidinones and dihydropyrimidines were first efficient aerobic oxidized to the corresponding pyrimidinones and pyrimidines, respectively, in high yields by molecular oxygen in the presence of catalytic amount of N-hydroxyphthalimide (NHPI) and Co(OAc)₂ in a mild and environmental benign condition.     

Facile fabrication of porous pure and Ag nanoparticle-doped poly(4-vinylpyridine) films at the liquid-liquid interfaces

We reported an interfacial self-assembly of regularly layered porous poly(4-vinylpyridine)(P4VP) films at the interfaces of water-chloroform or -dichloroethane.The porous diameters were in the range from hundred nanometers to several micrometers.It was revealed that formation of such kind of porous materials was solvent dependent.Moreover,cyclic Ag nanoparticles could be grown in the porous P4VP films to form Ag-P4VP nanohybrids under radiation.     

Ytterbium triflate hydrate catalyzed Michael addition and cyclocondensation of α,β-unsaturated ketones with active methylene compounds

Catalyzed by ytterbium（III） triflate hydrate [Yb（OTf）3.xH20], the Michael addition and cyclocondensation of α,β-unsaturated ketones with active methylene compounds to afford the 1,4-adducts and benzo[b]pyran derivatives, respectively were studied.     

0MATLAB在空间图形中的动态应用

学生空间思维的不足影响了学生对空间曲面的理解和重积分的学习。本文通过二个实例,重点讨论了用MATLAB动态生成空间图形的技巧。     

CID-ICP-AES用于高纯试样的分析性能

研究了CID-IP-AES用于测定高纯物质的分析性能。以高纯LiOH为对象，研究了低浓度范围内分析线的选择，标准曲线的特性，探讨了直接用于高纯物质分析的检测能力及可行性。