Influence of ultrasonic field on microcystins produced by bloom-forming algae

Under the background of algae removal and growth inhibition by ultrasonic irradiation, the effects of ultrasonic irradiation on removal of Microcystis, the concentration variation of microcystins (MC) produced by Microcystis in Microcystis suspension, and sonochemical degradation of microcystins in water, were studied in the paper. The results showed that ultrasonic irradiation could efficiently inhibit the growth of Microcystis, and ultrasonic irradiation shorter than 5 min would not introduce the increase of microcystins dissolved in Microcystis suspension simultaneity. Also, microcystins dissolved in Microcystis suspension would not increase as ultrasonic power increasing. Further research showed that microcystins were effectively degraded in ultrasonic fields. After 20 min ultrasonic irradiation at 150 kHz and 30 W, the removal rate of microcystins reached 70%.     

Synthesis of Novel Benzo-15-Crown-5-Tethered β-Cyclodextrins and Their Enhanced Molecular Binding Abilities by Alkali Metal Cation Coordination

Two novel benzo-15-crown-5 tethered β-cyclodextrins 1 and 2have been synthesized by coupling substituted benzo-15-crown-5 with correspondingβ-cyclodextrin derivatives. Their inclusion complexation behavior withrepresentative guests, such as cyclohexanol, cyclohexane carboxylic acid, cyclohexaneacetic acid, sodium cyclohexane carboxylate, and potassium cyclohexane carboxylate,was investigated in aqueous solution by means of fluorescence spectrometry. As compared with parent β-cyclodextrin, benzo-15-crown-5 tethered β-cyclodextrins 1–2 display significantly enhanced molecular binding abilities and selectivities towards model substrates, especially towards substrates containing alkali-metal cations. These results indicate that, bearing two recognition sites in a single molecule, these supramolecular architectures can strongly enhance the molecular binding ability of parent β-cyclodextrin by the cooperative binding of the β-cyclodextrin cavity and the crown ether moiety. Possessing a shorter linker, crown ether-β-cyclodextrin 2 shows much higher binding affinity with guest molecules than crown ether-β-cyclodextrin 1, which may be attributed to the binding size and molecular multiple recognition behavior between host and guest.     

超临界流体干燥过程的分析

以ZrOCl2•8H2O为原料，采用超临界流体干燥（SCFD）法，在短时间内制备出大孔体积高比表面ZrO2气凝胶超细粉．该法具有良好的稳定性和可靠性．建立了醇凝胶中液相含水量的分析方法，为产品质量控制及确认体系是否处于超临界状态提供了依据．对抽提后的溶剂分析表明，SCFD过程是一物理过程．对水的抽提干燥过程亦进行了初步的理论探讨．     

The adsorption and dissociation of O2 on Cu low-index surfaces

The extended LEPS of O(2)-Cu single crystal plane systems is constructed by means of 5-MP (the 5-parameter Morse potential). Both the adsorption and dissociation of O(2) on Cu low-index surfaces are investigated with extended LEPS in detail. All critical characteristics of the system that we obtain, such as adsorption geometry, binding energy, eigenvalues for vibration, etc., are in good agreement with the experimental results. Our calculated results suggest there are many differences between O(2)-Cu (110) and O(2)-Pd (110) systems. On a Cu (110) surface, O(2) adsorbs in a tilted configuration and there are two lowest energy dissociation channels along the [001] and [10] directions, respectively. We speculate that the adsorption geometry of O(2) on the metal surfaces relates to the lattice constant of metal. Meanwhile, We use the concepts of the molecular dissociation limit and the surface dissociation distance to analyze again the dissociation mechanism of the O(2) on the low-index surfaces.     

Self-assembled multivalent vancomycin on cell surfaces against vancomycin-resistant enterococci (VRE)

A vancomycin (Van) derivative self-assembles in a phosphate buffer as a divalent Van and on cell surfaces as a multivalent Van, which offers potent activity against VRE.     

Refractive index measurements of films with biaxial symmetry. 2. Determination of film thickness and refractive indices using polarized transmission spectra in the transparent wavelength range

A technique is formulated to determine both thickness and refractive indices of free-standing films with biaxial symmetry from polarized transmission spectra. The films must be transparent and show little dispersion in refractive indices in the wavelength range where the transmission spectra are collected. Methods are proposed to correct the errors caused by imperfect polarization of incident radiation and thickness variation across the sampling area. Anisotropic refractive indices and thickness of poly(biphenyl dianhydride-p-phenylenediamine) films which exhibit uniaxial optical anisotropy are determined from polarized transmission spectra. The refractive index and thickness values compare well to those obtained from waveguide prism coupler and profilometer measurements.     

CuO-BaO/SiO2催化剂的结构表征

以XRD、XPS和EXAFS手段对CuO－BaO／Sic2催化剂及其还原态的结构进行了研究．结果表明，在CuO－BaO／SiO2体系中铜和钡都是以氧化态的形式存在，超细SiO2载体对所负载的CuO的结构有影响．随着样品负载量的逐渐降低，Cu－O和Cu－Cu睡的健长和配位数逐渐征小，而且低载量样品的健长和配位数减小的幅度最大．在总负载量＞13．39％的样品中，CuO以晶相的形式存在；总负载量＜13．39％的样品中，CUO呈现单层分布的高分出状态．还原态样品中钢以本价铜的形式存在，随负载量的降低，还原态Cu－Cu健的镇长和配位数也分别呈现出逐渐减小的趋势．还原态中心铜原子在催化剂表面的分布状态基本上保持了氧化态催化剂中CuO物相的分市状态．     

非缔合二元有机液体混合物过剩热容的测定与计算

溶液的过剩热容是热力学的重要函数，对其测定与研究具有理论与实际意义．过剩热容不仅可检验溶液中分子间的相互作用，并可利用其计算混合物的热容．本文报告了用微量热仪对环乙烷一本等七个二元物系全浓度范围内在29815K、常压下过剩热容CEp进行的测定工作，上述体系是由具有     

Ru-Catalyzed asymmetric hydrogenation of alpha-ketoesters with CeCl3.7H2O as additive

[reaction: see text] An efficient asymmetric hydrogenation of alpha-ketoesters is reported with use of a catalyst prepared from [Ru((S)-3)(benzene)Cl]Cl and CeCl(3).7H(2)O. Alpha-hydroxy esters are obtained in up to 96% ee. The addition of CeCl(3).7H(2)O not only improves the enantioselectivity, but also enhances the stability of the catalyst. As a result, the hydrogenation of methyl benzoylformate affords the product with 92% ee with a substrate/catalyst ratio of 10 000. Hydrolysis of 2 provides the final compound with 83% yield at 99% ee after a single recrystallization from 1,2-dichloroethylene.     

An approach for solving fuzzy multi-criteria decision problem under linguistic information

Fuzzy Optimization and Decision Making - Linguistic information processing exists in multi-criteria decision making, and linguistic truth-valued lattice implication algebra (LTV-LIA) has definite...