相互影响 发表于 2025-3-26 21:55:00
Characterization of organic materials by means of electrofocusing,nds that localize mainly in the acid region of the pH gradient, whereas after some months of incubation a much more complex pattern of bands develops, characteristically, in the neutral region of the gradient. Such development of new fractions is markedly evident if incubation is carried out in summConjuction 发表于 2025-3-27 01:47:42
Nature of humic substances of Mollisol and Luvisol in the Canadian Prairies,The amount of humic acid (HA) was higher in the Mollisol than in the Luvisol. The opposite trend was observed for fulvic acid (FA). There was no great difference in elemental composition of HAs between the Mollisol and Luvisol. The contents of N and S of the FAs were higher in the Mollisol than in t爱哭 发表于 2025-3-27 08:52:33
http://reply.papertrans.cn/43/4300/429932/429932_33.png反抗者 发表于 2025-3-27 11:41:47
Solid state 13C CP MAS NMR characterization of the chemical structure of terrestrial organic matterolid state .C NMR using Cross Polarisation and Magic Angle Spinning (CP MAS). The examination was done on whole soil samples, because isolation and separation of humic substances may alter the chemical structure of the organic matter. The soil samples all appeared to have small amounts of aromatic a平庸的人或物 发表于 2025-3-27 16:22:31
Carbon-13 nuclear magnetic resonance analysis, lignin content and carbohydrate composition of humictracted from living and dead . and salt marsh sediments. With these methods, there was little evidence for early diagenetic alteration of the humic materials. No trends consistent for fulvic and humic acids were observed for either hydrolyzable carbohydrates or lignin derived phenols, and chemical mimpaction 发表于 2025-3-27 19:02:02
The effect of composting on the organic colloidal fraction from domestic sewage sludge,le polymers from composted and uncomposted sludges were described..The alkali-soluble, acid-insoluble sludge fraction (humic-like) was isolated after exhaustive lipid extraction, and analyzed by chemical degradation followed by combined gas chromatography mass spectrometry. It was observed that this失败主义者 发表于 2025-3-28 00:38:09
http://reply.papertrans.cn/43/4300/429932/429932_37.pngObsessed 发表于 2025-3-28 03:32:23
http://reply.papertrans.cn/43/4300/429932/429932_38.png补角 发表于 2025-3-28 08:02:24
Cobaltihexamine as an index cation for measuring the cation exchange capacity of humic acids,etter resolved than acid base titration curves in 0.1 M NaClO. and were slightly displaced towards lower pH values. Three adsorption maxima were obtained in the pH range 3 to 10, and these corresponded to functional group entities observed in δpH/δml curves from acid-base titration.减震 发表于 2025-3-28 13:05:50
Some aspects of the characterization of humic substances in lake waters,f the analyses are discussed in relation to the sample isolation (DOM, FA or HA). Multivariate analyses showed some trends in the average molecular masses, in the results of elemental analyses and, especially, in the characteristics of the .C NMR spectra so far obtained.