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%.     

C NMR spectra of cyclomercurated ferrocenylimines: Substituent effects and conformations in the ferrocenes

Three series of cyclomercurated ferrocenylimines (2-chloromercurio-ferrocenylimines) have been studied using ¹³C NMR spectroscopy. Good to excellent linear relationships have been found to exist between the chemical shifts of the carbon atoms in the ferrocenyl moiety and normal Hammett substituent constants σ_m and σ_p. The δ values of the iminyl carbon atoms show excellent linear correlations with the σ values. In three series of the ferrocenes, the sensitivity of the carbon atoms to the substituent effect is different, which is discussed in terms of the twist angle between the N-phenyl ring and the C---C=N---C plane. The relative sensitivity of the chemical shifts on different positions in ferrocenyl moiety to the substituent effect has also been presented.     

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．     

Loss and recovery in hydrophobicity of silicone rubber exposed to corona discharge

This paper describes the loss and recovery in the hydrophobicity of unfilled high temperature vulcanized silicone rubber (HTV-SR) resulting from corona discharge. In this study, HTV-SR specimens were exposed to corona stress generated by a parallel needle-plane electrode system, and physicochemical analyses on the surface layer of SR before and after corona discharge treatment were carried out by using Fourier transform infra-red (FTIR) spectroscopy, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). It is demonstrated that hydrophilic OH groups that are by-products of ageing can be formed instead of hydrophobic CH₃ groups on the surface of aged SR and the corona discharge plays an important role on the temporary loss of hydrophobicity. After a substantial period of ‘rest’, the hydrophobic recovery of SR results from the diffusion of low-molecular weight (LMW) silicone fluid from the bulk onto the aged layer.     

ortho-Mercuration of ferrocenylimines

The mercuration of a series of aryliminomethylferrocenes occurred predominantly in an ortho-position of the substituted ferrocenyl ring to yield 2-mercurated ferrocenylimines. The regiospecificity of this reaction suggests that the mercury is directed into the ortho-position by coordination of the mercury to imino nitrogen with subsequent electrophilic substitution. The chromatographic and spectral properties of the 2-mercurated products show the presence of an intramolecular N → Hg coordination via the five-membered ring in these molecules, which was further confirmed by the single-crystal structure analysis of 2-chloromercuro-1-[(4-methoxyphenylimino)methyl]ferrocene.     

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.     

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.     

A five-channel grating spectrometer for millimeter-waves

A five-channel grating spectrometer for use in millimeter wave band (25100GHz) is described with its design theory of optical path, and measured results of insertion loss and resolving power.