Hydroxyl-functionalized ionic liquid: a novel efficient catalyst for chemical fixation of CO2 to cyclic carbonate

A series of hydroxyl-functionalized ionic liquids (HFILs) were synthesized and characterized. They showed efficient reactivity and reusability toward the coupling of epoxide and CO₂ without any additional co-catalyst and organic solvent. Highest activity and selectivity were achieved in the presence of 1-(2-hydroxyl-ethyl)-3-methylimidazolium bromide (HEMIMB) in comparison with other similar catalysts investigated. The relationship between the higher catalytic reactivity and OH-functional group was proposed.     

On the Ising Model with Strongly Anisotropic External Field

In this paper we analyze the equilibrium phase diagram of the two-dimensional ferromagnetic n.n. Ising model when the external field takes alternating signs on different rows. We show that some of the zero-temperature coexistence lines disappear at every positive sufficiently small temperature, whereas one (and only one) of them persists for sufficiently low temperature.     

多元统计分析在医院管理中的应用

本文应用多元统计分析中的聚类分析和因子分析法 ,对辽宁省金秋医院内科循环病房 1997- 1999年的月报表进行了综合评价 ,借以说明多元统计分析用于医院管理的实用性与优越性     

Preparation and characterization of bilayer carbon/polymer membranes

The objective of the present research work was to develop a membrane with a high H₂O/alcohol selectivity for pervaporation and for use in direct alcohol fuel cells. Sulfonated poly (ether ether ketone) (SPEEK) was coated with a thin continuous carbon molecular sieve (CMS) layer. The membranes obtained had 180- and 400-nm thick CMS layers that led to a clear reduction of alcohol crossover. The water/alcohol selectivity increased with the size of the alcohol molecules as follows: methanol < ethanol < n-propanol < iso-propanol. A water/n-propanol selectivity of up to 34,000 was obtained, confirming the molecular sieving effect. The system was tested in a direct methanol fuel cell using standard electrodes, and demonstrated a better performance than with plain membranes. In a later stage Pt was introduced in the CMS layer during the preparation of the membrane electrode assemblies, this had the advantage that the CMS layer not only acted as an alcohol barrier but also as a catalyst support.     

n—型聚乙炔复合膜电极性能的研究

自MacDiarmid等将聚乙炔(PA)做为二次电池的电极材料以来,其电化学特性和行为引起了人们的极大兴趣.随后的研究表明,p-型PA[(CH)~(y )Ay~-]_x在电解液中不稳定,用ClO_4~-掺杂的PA充放循环时有降解发生.n-型PA[My~ (CH)~(y-)]_x(y≤0.10)在THF/LiClO_4电解质中较稳定,电化学还原完全可逆,目前已实现1100次充放循环.因此,它既可做电池的正极材料(碱金属为负极),又可做负极材料(TiS_2为正极).我们发现