Degradation products formed during UV-irradiation of humic waters

Natural humic lake water and aqueous solutions of humic substances were treated with ultraviolet (UV) radiation (λ = 254 nm). The effects on the dissolved organic carbon content (DOC) and the absorbance at 254 nm (Abs254) and 460 nm (Abs460) were monitored and the identity and concentrations of gas chromatographable organic degradation products were determined. The DOC content and the (Abs254) of the humic solutions decreased continuously with increasing UV-dose. Several aromatic and aliphatic degradation products were identified and roughly quantified The concentrations of aromatic hydroxy carboxylic acids and hydroxy aldehydes increased when relatively low UV-doses were used, but declined following further irradiation. The concentrations of aliphatic dibasic acids increased over the full range of UV-doses

沙产业发展现状及前景展望

沙产业是开发利用沙区地下、地面和地上的多种资源 ,创建沙地农业型和非农业型产业 ,形成产品系列生产 ,以获取持续规模的效益。制约沙产业发展的瓶颈因素是水。我国对沙区资源的开发利用已扩大到多个领域 ,沙区用材林基地建设、泥炭资源开发利用、热管技术应用、石油天然气开采等都初具规模。 2 1世纪将是沙产业崛起的世纪 ,发展沙产业前景广阔。

Nitrogen-15 signals of leaf-litter-soil continuum as a possible indicator of ecosystem nitrogen saturation by forest succession and N loads

National Key Research and Development Program [2010CB833502]; National Natural Science Foundation of China [30600071, 40601097, 30590381]; Chinese Academy of Sciences [KZCX2-YW-432, O7V70080SZ, LENOM07LS-01]; GUCAS [O85101PM03]