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31.
Hideko Koshima Teruo Matsuura 《Journal of photochemistry and photobiology. A, Chemistry》1996,100(1-3):85-91
This paper deals with the solid state bimolecular photoreactions occurring at the interface between crystallites of two different organic compounds prepared as a polycrystalline mixture by melting-resolidification. The photoreactions include the photoaddition of NH compounds to aromatic and olefinic double bonds, hydrogen abstraction, condensation reaction via photoelectron transfer and [2+2] photoaddition. Particular attention is focused on the characterization of the polycrystalline mixture, the selectivity of the photoreactions in the solid state compared with those in the solution phase and the factors controlling the photoreactions. 相似文献
32.
用内径为0.53mm的填充毛细管正相液相色谱为第一维,用4.6mm(i.d.)×50mmRP-18e整体柱反相色谱为第二维,建立了定量环一阀切换接口的全二维液相色谱系统(NPLC×RPLC).第一维色谱分离洗脱出的组分交替存储在十通阀上的两个定量环中,同时定量环中前一个组分被转移到第二维进行反相分离.因为第一维的流动相流量仅是第二维的1/500,自然解决了流动相兼容问题.采用芳香族化合物的混合物和中药丹参正己烷提取液对该全二维液相系统的分离能力进行了评价. 相似文献
33.
Roger Douillard 《Colloids and surfaces. B, Biointerfaces》1993,1(6):333-340
Knowledge of the equation of state of adsorbed or deposited layers of proteins at the air/water interface is of fundamental interest in the understanding of the surface activity of these molecules. Using scaling laws of current polymer theories, it has been shown that the equation of state of the interfacial layer in the semi-dilute regime should relate the surface pressure to the surface concentration through a power law. The exponent of this power law should reflect the quality of the solvent and the conformation of the adsorbed polypeptide chain. In the case of β-lactoglobulin layers, in the range of surface concentrations that should correspond to the semi-dilute regime, the relationship between surface pressure and surface concentration is expressed as a power law. The exponent of this power law is strongly influenced by the nature of the aqueous substrate and by the net charge of the protein molecule. The use of scaling laws gives a coherent view of the expansion of the polypeptide chain in the interfacial layer and of the relationship between surface concentration and surface pressure in the semi-dilute regime. This result favours a strong similarity between β-lactoglobulin and a polymer chain in the interfacial layer. It is concluded that current theories of polymer adsorption could be applied to interfacial protein layers. 相似文献
34.
Kwang-il ChungJung-Do Lee Eui-Jung KimWoo-Seong Kim Jung-Hwan ChoYong-Kook Choi 《Microchemical Journal》2003,75(2):71-77
Although a lithium metal anode has a high energy density compared with a carbon insertion anode, the poor rechargeability prevents the practical use of anode materials. A lithium electrode coated with Li2CO3 was prepared as a negative electrode to enhance cycleability through the control of the solid electrolyte interface (SEI) layer formation in Li secondary batteries. The electrochemical characteristics of the SEI layer were examined using chronopotentiometry (CP) and impedance spectroscopy. The Li2CO3-SEI layer prevents electrolyte decomposition reaction and has low interface resistance. In addition, the lithium ion diffusion in the SEI layer of the uncoated and the Li2CO3-coated electrode was evaluated using chronoamperometry (CA). 相似文献
35.
N. Muthukumar S. Maruthamuthu A. Ilangovan N. Palaniswamy 《Surface and interface analysis : SIA》2007,39(6):533-541
Biodegradation occurs in the diesel/water interface in petroleum product pipelines. The microbial contamination can result in inhibitor/fuel degradation, leading to unacceptable levels of turbidity, filter plugging, storage tank corrosion and stored product souring. Therefore, selection of the biocide/inhibitor plays an important role in the transportation of petroleum products through pipelines. Three biocides (cationic and nonionic) were employed to study the biodegradation in a diesel‐water interface. The biocidal efficiency against degradation of diesel was examined by employing Fourier‐transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy and gas chromatography mass spectrometry (GC‐MS) techniques. Bronopol (2‐bromo‐2‐nitro‐propane‐1, 3‐diol) was found to have higher bactericidal efficiency than N‐cetyl‐N,N, N‐trimethyl ammonium bromide (CTAB) and cetyl pyridinum bromide (CPB). But the cationic biocides (CTAB and CPB) showed good biocidal efficiency at the interface. The data are explained in terms of a model that postulates the formation of a ‘micelle’ at the diesel‐water interface. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
36.
R. Lalrempuia Patrick J. Carroll K.A. Kreisel 《Journal of organometallic chemistry》2005,690(17):3990-3996
The reactions of [(ind)Ru(PPh3)2CN] (ind = η5-C9H7) (1) and [CpRu(PPh3)2CN] (Cp = η5-C5H5) (2) with [(η6-p-cymene)Ru(bipy)Cl]Cl (bipy = 2,2′-bipyridine) (3) in the presence of AgNO3/NH4BF4 in methanol, respectively, yielded dicationic cyano-bridged complexes of the type [(ind)(PPh3)2Ru(μ-CN)Ru(bipy)(η6-p-cymene)](BF4)2 (4) and [Cp(PPh3)2Ru(μ-CN)Ru(bipy)(η6-p-cymene)](BF4)2 (5). The reaction of [CpRu(PPh3)2CN] (2), [CpOs(PPh3)2CN] (6) and [CpRu(dppe)CN] (7) with the corresponding halide complexes and [(η6-p-cymene)RuCl2]2 formed the monocationic cyano-bridge complexes [Cp(PPh3)2Ru(μ-CN)Os(PPh3)2Cp](BF4) (8), [Cp(PPh3)2Os(μ- CN)Ru(PPh3)2Cp](BF4) (9) and [Cp(dppe)Ru(μ-CN)Os(PPh3)2Cp](BF4) (10) along with the neutral complexes [Cp(PPh3)2Ru(μ-CN)Ru (η6-p-cymene)Cl2] (11), [Cp(PPh3)2Os(μ-CN)Ru(η6-p-cymene)Cl2] (12), and [Cp(dppe) Ru(μ-CN)Ru(η6-p-cymene)Cl2] (13). These complexes were characterized by FT IR, 1H NMR, 31P{1H} NMR spectroscopy and the molecular structures of complexes 4, 8 and 11 were solved by X-ray diffraction studies. 相似文献
37.
Rupert B. Hurley 《Journal of separation science》1980,3(3):147-148
This paper describes a design for an all-glass GC/MS interface. The design has advantages due to low dead volume, lack of column effluent adsorption and degradation, simple interface production and installation, and ease of column mounting/dismounting. 相似文献
38.
《Electroanalysis》2006,18(7):649-654
For the first time, the voltammetry of an ensemble of immobilized benzonitrile microdroplets containing 5,10,15,20‐tetraphenyl‐21H,23H‐porphine iron (III) chloride, TPPFeCl immobilized at platinum electrodes immersed in various aqueous electrolytes has been explored. The reduction of TPPFeCl was observed with the voltammetric response seen to be highly dependent on the nature of ions in the surrounding aqueous phase. Unlike voltammetry in purely homogeneous solution the nature of the aqueous electrolyte can influence the voltammetry in the droplet phase. The electrochemical reduction of TPPFeCl contained within tetrabutylammonium chloride (TBACl) supported benzonitrile (PhCN) microdroplets immersed into an aqueous solution of TBACl was first studied. During TPPFeCl reduction the resulting [TPPFeCl]? species is stabilized due to the excess of chloride anions inside the oil droplet. Voltammograms of homogeneous solutions of PhCN supported with TBACl show similar chemically reversible process which is also attributed to the stable [TPPFeCl]? species. This anion stabilization was not observed when the oil droplets were supported with tetrabutylammonium perchlorate (TBAP) or when the PhCN solution bathing the microdroplet ensemble was supported with TBAP resulting in a chemically irreversible process. The voltammetry of unsupported droplets immobilized on a platinum electrode immersed in different aqueous electrolytes was also explored and the fate of the [TPPFeCl]? species formed considered during the reduction sweep. Similarities and difference to voltammetry in purely homogeneous media are noted and the use of droplet voltammetry provides complimentary information. 相似文献
39.
A convenient synthetic approach is established to prepare a new class of 1-l-α-amino acid derivatives of phospholene oxides by amination of (±)-1-chloro-2-phospholene-1-oxides with several optically pure l-α-amino acid esters. All compounds obtained as a diastereomeric mixture in good to high yields. The two diastereomers were successfully separated by column chromatography and structurally identified by their spectral analyses. 相似文献
40.
《Surface and interface analysis : SIA》2005,37(10):773-781
The formation of a passivation film (solid electrolyte interphase, SEI) at the surface of the negative electrode of full LiCoO2/graphite lithium‐ion cells using LiPF6 (1M ) in carbonate solvents as electrolyte was investigated by means of x‐ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The analyses were carried out at different potentials of the first and the fifth cycles, showing the potential‐dependent character of the surface‐film species formation. These species were mainly identified as Li2CO3 up to 3.8 V and LiF up to 4.2 V. This study shows the formation of the SEI during charging and its partial dissolution during discharge. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献