Synthesis of (R)-cyanohydrins by crude (R)-oxynitrilase-catalyzed reactions in micro-aqueous medium

In diisopropyl ether or ethyl acetate under micro-aqueous conditions, the enantioselective synthesis of (R)-cyanohydrins from aldehydes and methyl ketones was studied using crude (R)-oxynitrilase prepared from almonds. This reaction system performed well over the temperature range of 4°C to 30°C.     

火焰原子吸收光谱法测定爬地虎中6种微量元素

用湿法和干法分别对爬地虎进行处理,采用火焰原子吸收光谱(FAAS)法,利用标准曲线测定爬地虎中几种微量元素的浓度。在优化的仪器工作条件下,对爬地虎果中6种微量元素可进行分别测定,互不干扰,结果的相对标准偏差在0.70%~4.0%,加标回收率在90.0%~108%,方法简便、快速、准确。     

分光光度法在制备负载型多糖吸附污水中铅的应用

本文用不同活性炭制备了负载型多糖（活性炭改良）,多糖的负载率用硫酸苯酚法测定,标准曲线回归方程为Y=0.005906X+0.1234（ r=0.9998）,RSD为0.7%,线性范围为5~50.0mg/L,耶壳活性炭多糖负载率最高为65.71%。用自制负载型多糖清除污水中的铅,以甲基百里香酚蓝为显色剂,用光度法测定铅吸附率,测定条件为,室温、波长为610nm、甲醇为增敏剂、pH为6、显色剂用量为1.5mg/L,反应时间50min,方法的标准曲线回归方程为Y=0.0682X+0.1825（r=0.9999）,线性范围为0～8.0mg/L。平均6次的检出限为0.2mg/L,加标回收率在96.8%～102.3%,RSD为0.39%～3.2%,同时作了共存离子的干扰。结果不同负载型多糖对铅离子的吸附不同,其中椰壳活性炭负载多糖对铅的吸附最大为28.61%,比相应活性炭对铅的吸附高了16.08%。将多糖负载在活性炭上,可明显提高对铅离子的吸附,所以该研究为清除实际污水乃至土壤中的铅提供依据。     

ω-非常凸空间与ω-非常光滑空间

本文研究了ω-非常凸空间和ω-非常光滑空间的问题.利用局部自反原理和切片证明了ω-非常凸空间和ω-非常光滑空间的对偶关系,讨论了ω-非常凸空间和ω-非常光滑空间与其它凸性和光滑性的关系,给出了ω-非常凸空间与ω-非常光滑空间的若干特征刻画,所得结果完善了关于Banach空间凸性与光滑性理论的研究.     

Non-equilibrium electric surface phenomena

Non-equilibrium aspects of traditional electrokinetic phenomena (electrophoresis, electroosmosis, streaming potential, sedimentation potential), electrostatic interaction of particles and new electrokinetic phenomena are considered. The significance of non-equilibrium electric surface phenomena for many major areas of modern colloid science (characterization of colloids, membrane science, transport phenomena and separation, particle interaction and coagulation) is established.The study of non-equilibrium electric surface phenomena is connected with the validation of the standard electrokinetic model (SEM), the development of a non-standard model and the development of an extensive programme of disperse system characterization based on integrated electrokinetic investigations. Experimental and theoretical studies of systems with a smooth, non-porous impermeable surface (mica in Anderson's experiments, and quartz microcapillaries with a molecule-smooth surface in Churaev's experiments) have shown that usually there are no significant difficulties in interpreting electrokinetic investigations despite the possible anomaly in the water structure near the surface and the possibility of maximum shear stress (yield stress), i.e. the anomalous viscosity and decreased dissolving power with respect to ions. However, systems which do not satisfy the conditions of the SEM are widely distributed, owing to the porosity, roughness or permeability of the boundary layer of the surface of the solid body which simultaneously belongs to the solid and liquid phases. In this layer, enclosed between the outer Helmholtz plane and the slipping plane, the motion of the liquid strongly slows down and the tangential flow of ions is characterized purely by the mobility which is close to the normal. Thus, a general property of a non-standard electrokinetic model is the presence of an anomalous (additional) surface conductivity in excess of the surface conductivity determined according to Bikerman's equation based on the ζ -potential alone.Confidence in modelling the electrokinetic phenomena has grown with the development of methods for modifying the surface such that its properties approach those of the SEM (Bijsterbosch and co-workers; Saville and co-workers).Extension of the particle characterization concept requires the measurement of both the mobile charge and the electrokinetic charge and from this an estimate of the thickness of the additional conductivity zone can be made. With the additional measurement of a titratable charge, it is possible to estimate the ion distribution between the dense and diffuse parts of the double layer (DL) and to estimate the decreased mobility of ions in the Stern layer or in the immobilized part of the DL.Quantitative laws governing the interaction of particles and corresponding to the non-standard model substantially differ from the traditional laws described by the DVLO theory as applied to the SEM. This is also true for adsorption properties which are characterized without sufficient reason by means of the ζ-potential. Therefore both the development of models of interaction and adsorption of ions, allowing for the non-standard electrokinetic model, and the extension of the particle characterization programme to integrated investigations of electric surface phenomena are required.Further generalization of the theory of electrokinetic phenomena is achieved. In addition to the surface charge another variety of surface force can be the origin of the electrokinetic phenomena.     

Direct and roughness-induced indirect transitions in photoemission from silver films

One-photon and two-photon electron emission spectra from vapour deposited rough and smooth Ag films are compared. Photoemission from rough films is strongly enhanced due to the participation of localized surface plasmons (LSP). A theory is outlined that successfully estimates the enhancement and predicts that LSP-initiated photoemission would involve momentum non-conserving transitions.     

The Higgs model for anyons and Liouville action

We connect Liouville theory, anyons and Higgs model in a purely geometrical way.     

Ligand shift in mixed-cluster complexes: synthesis of alkyne-bridged Co2Mo2 clusters with two triply-bridging sulphur atoms: crystal structure of [Co2Mo2(η5-Cp)2(μ3-S)2(μ4-CF3C2Me)(CO)4]

Reaction of the complexes [(CO)₃Co(μ-RC₂R′)Co(CO)₃] (R = R′ = CF₃; R = Ph, CF₃ and R′ = H) with the MoMo dinuclear derivative [Mo₂Cp₂(μ-SMe)₂(CO)₂] leads to cleavage of both CS and CH bonds with the formation of closo-octahedral Mo₂CO₂C₂ clusters stabilised by a μ₄-η²-bound alkyne. An X-ray diffraction study has shown that the two Mo₂Co faces of the octahedron are capped by triply-bridging sulphur atoms.