Reorientational dynamics in a liquid organized system: Brillouin and depolarized Rayleigh scattering experiments in 1-octanol

Light scattering experiments, with dispersive and interferometric techniques, have been performed to study the orientational relaxation dynamics in 1-octanol, a structured liquid system having quite long living H-bonded clusters. Different temporal windows have been opened with these experiments to investigate the temporal events connected to the orientational relaxation dynamics of this molecular liquid. The present results have been compared with previous Monte Carlo MD simulations and experimental dielectric relaxation functions. They show that in the high frequency domain two additional very fast processes can be detected which have not been revealed by dielectric function relaxation.     

THE RESOLUTION OF CHLOROPHYLL a/b BINDING PROTEINS BY A PREPARATIVE METHOD BASED ON FLAT BED ISOELECTRIC FOCUSING

We describe a new fractionation method for intrinsic membrane proteins based on flat bed isoelectric focusing (IEF) in granulated gel. The characteristics of the separation in the presence of the non-ionic detergent dodecylmaltoside are considered. The method has been applied to the fractionation of chlorophyll a/b binding proteins from chloroplast grana membranes. Several Light Harvesting Complexes II (LHC II) have been resolved showing differences in their polypeptide composition. Probing with monoclonal and polyclonal antibodies showed that polypeptides belonging to different [EF fractions with the same mobility in denaturing sodium dodecyl sulphate polyacrylamide gel electrophoresis, are immunologically distinct polypeptides. This is the first report of the presence in the thylakoid membrane of a number of LHCII polypeptides that may reflect the genetic complexity of the Cab genes. Moreover preparative amounts have been obtained of the minor chlorophyll a/b proteins CP 29, CP 26 and CP 24 that have been recently described. The analysis of a currently used LHCII preparation by the present method shows that this fraction is actually contaminated by two minor chlorophyll a/b proteins.     

MgB2／Fe带材Jc的各向异性及MgB2芯织构和成分不均一性的研究

本文研究了在不同磁场方向和温度下非原位Fe包套MgB2单芯带Jc的各向异性，通过对各种工艺条件下带材中MgB2芯的X-ray衍射图进行拟合分析和计算，比较了MgB2芯在Fe-MgB2界面和中心处的织构度和成份不均一性．研究发现带材Jc的各向异性受初始粉末颗粒尺寸的影响．由于受套管材料强度和形变加工工艺的影响，MgB2芯在Fe-MgB2界面处比在中心处有较强的织构．在MgB2-Fe的界面处，700℃淬火样品的X-ray衍射图中发现了由中间相Fe23B6生成的金属间化合物Fe2B另外还研究了MgB4和MgO等主要杂质相的形成原因．