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1.
Shufeng Zuo 《Applied Surface Science》2006,253(5):2508-2514
Al-pillared clays supported rare earths (RE/Al-PILC) are prepared and used as supports of palladium catalysts for deep oxidation of low concentrations of benzene (130-160 ppm). The supports and catalysts are characterized by X-ray powder diffraction (XRD), FT-IR, BET, transmission electron microscopy (TEM) and temperature-programmed reduction (H2-TPR). The results show that Al-pillaring results in a strong increase in the basal spacing (d0 0 1) from about 1.2 to 1.8 nm, and an increase in the BET surface area from 63.6 (±3.2) to 238.8 (±11.9) m2/g. Activity tests of deep oxidation of low concentration benzene show catalysts supported on Al-PILC and RE/Al-PILC are obviously more active than that on raw clay. Pd/6% Ce/Al-PILC, in particular, can catalyze the complete oxidation of low concentration benzene at a temperature as low as about 290 °C. 相似文献
2.
Zhaohui Wang 《Thermochimica Acta》2004,414(1):31-33
Microcalorimetric measurements of excess molar enthalpies, at 298.15 K, are reported for the four binary systems formed by mixing 1-hexene with the cycloalkanes: cyclohexane and methylcyclohexane, and with the aromatic hydrocarcons: benzene and toluene. Smooth Redlich-Kister representations of the results are presented. It was found that the Liebermann-Fried model also provided good representations of the results. 相似文献
3.
The sorption, diffusion, and pervaporation (PV) properties of benzene/cyclohexane (Bz/Cx) mixtures on cation-exchange membranes containing copper ions (Cu(II)) were investigated. The equilibrium sorption isotherms of pure vapors in the membranes and the partial solubility of binary solutions in the membranes were described using the UNIQUAC model. The τiM and τMi values were 0.978 and 0.591 for Bz, and 0.922 and 0.475 for Cx. The transient regimes of vapor sorption were employed to calculate the concentration-dependent diffusion coefficients. Long’s model sufficiently explained the diffusivity of Bz and Cx in the membranes. The pre-exponential factors were 3×10−13 m2/s and the plasticization factors were 3.0 and 3.6 for Bz and Cx, respectively. Excellent agreement was found with the experimental results applying the solubility and diffusivity data to simulate the pervaporation performance (flux and selectivity) using the modified Maxwell–Stefan equation. The membrane containing Cu(II) demonstrates better facilitating capability for Bz transport than that with Na(I), mainly due to its preferential sorption property toward Bz. Replacing Na(I) with Cu(II) into a Neosepta membrane resulted in better separation efficiency and higher Bz flux throughout the entire Bz concentration range. 相似文献
4.
BIOMARKERS INDICATING SEDIMENTARY PALEOENVIRONMENTS 总被引:3,自引:0,他引:3
Samples involved in this paper are 35 pieces of crude oils and 43 pieces of source rocks, from which a series of biomarkers, capable of indicating paleoecology and paleoenvironment. This will provide a scientific basis for tracing back to sedimenta-y paleoenvironment and paleoecology. 相似文献
5.
Titration calorimetry was used to construct the solid-liquid equilibrium line in ternary systems containing the solute and an aqueous mixed solvent by measuring the heat of dissolution of the solid solute during successive additions of the liquid solvent. The plot of cumulated heats versus the mole ratio, nsolvent/nsolute, yields two (almost) linear increases of different slopes. These two lines represent successively the enthalpy of dissolution then the enthalpy of dilution of the medium; their intersection gives the solubility and the enthalpy of dissolution of the solute. Phase diagrams have been established over the whole concentration range for o-anisaldehyde, 1,3,5-trimethoxybenzene and vanillin, in water + methanol, +ethanol, or +n-propanol at 303, 313 and 318 K. 相似文献
6.
7.
A. de la Hoz C. Pardo J. Elguero M. L. Jimeno 《Monatshefte für Chemie / Chemical Monthly》1992,123(1-2):99-104
Summary The reaction of tetracyanoethylene oxide on one hand and toluene, chlorobenzene, fluorobenzene, anisole, and nitrobenzene, on the other, has been studied. Toluene and the halogenobenzenes yield mixtures of monoadducts, anisole yieldp-methoxyphenylmalononitrile and its dimer and nitrobenzene does not react. These results are discussed with the help of a qualitative orbital model.1H-NMR analysis of some monoadducts has been carried out.
Der Benzolring als Dipolarophil: Reaktionen monosubstituierter Benzole mit Tetracyanoethylenoxid
Zusammenfassung Es wurden die Reaktionen von Tetracyanoethylenoxid mit Toluol, Chlorbenzol, Fluorbenzol, Anisol und Nitrobenzol untersucht. Toluol und die Halogenbenzole ergaben Mischungen von Monoaddukten, Anisol ergabp-Methoxyphenylmalononitril und sein Dimer, Nitrobenzol zeigte keine Reaktion. Diese Resultate werden mit Hilfe eines qualitativen Orbitalmodells diskutiert. Die Analyse einiger Monoaddukte erfolgte mittels1H-NMR-Analyse.相似文献
8.
Summary The interaction of some benzene and naphthalene derivatives with sodium dodecyl sulphate, hexadecyltrimethylmmonium bromide and polyoxyethylene [23] dodecanol micelles has been evaluated by high operformance liquid chromatography using micellar mobile phases. The micelle-solute association constants have been obtained for the compounds investigated. Good correlation between free energy of transfer for water-micelles and for octanol-water has been observed. 相似文献
9.
Structural characterization of lipopeptide biomarkers isolated from Bacillus globigii 总被引:2,自引:0,他引:2
Spectra obtained using matrix-assisted laser desorption/ionization (MALDI) mass spectrometry of Bacillus globigii (Bacillus subtilis niger) spores, vegetative cells and the culture supernatant show a cluster of biomarkers centered at a molecular mass of 1478 Da. Three biomarkers were isolated from the cell-free culture supernatant by solid-phase extraction and reversed-phase high-performance liquid chromatography, and characterized using various kinds of mass spectrometry. A Fourier transform mass spectrometer with a MALDI source was used to determine the monoisotopic protonated masses at 1463.8, 1477.8, and 1505.8 Da in order of elution. The mass differences of 14 and 28 Da suggest that they are homologous molecules. Alkaline hydrolysis of each species showed that it contained a lactone linkage. Strong acid hydrolysis released a fatty acid from an amide bond, consistent with a lipopeptide. A quadrupole time-of-flight instrument with a nanospray source was used to sequence the hydrolyzed forms of the three biomarkers. The cyclic lipopeptides were found to have amino acid sequences identical with those in fengycins and plipastatins, antimicrobial compounds with phospholipase inhibitor activity, previously identified in related species of Bacillus subtilis and Bacillus cereus. 相似文献
10.
口腔癌系头颈部癌,癌组织均位于口腔内,其非侵入性早期诊断是减少该病死亡的有效手段.唾液系口腔癌变相关物质首先释放进入的体液,取材方便,安全无创,是口腔癌普查筛选、早期诊断的首选指标.本文对唾液肿瘤生物标志物的种类、目前国内外常用的检测方法进行概述,重点阐述新型电化学生物传感方法在口腔癌相关唾液肿瘤生物标志物检测方面的相关应用及其最新研究进展.并对口腔癌相关唾液肿瘤生物标志物电化学传感技术的未来发展方向提出展望,拟为其深入研究与应用提供参考. 相似文献