ABSTRACT
An Fe-catalyzed unprotected hydroxylamine mediated Heck-type coupling between sulfinic acids and alkenes for the regioselective synthesis of (E)-vinyl sulfones has been developed. Mechanism studies indicated for the first time that a radical process may be involved and that hydroxylamines play multiple roles, including those of a mild oxidant and an in situ base. It was found for the first time that this transformation not only realizes C-S bond construction promoted by unprotected hydroxylamines, but also provides a practical and complementary method for the preparation of structurally important (E)-vinyl sulfones.
Subject(s)
Hydroxylamines , Iron , Hydroxylamines/chemistry , Iron/chemistry , Catalysis , Sulfones/chemistryABSTRACT
Based on the study of the content, forms, and spatial distribution of phosphorus (P) in the surface and columnar sediments of the Sihe River, the relationships between the total phosphorus (TP) and various forms of P and the basic physical and chemical properties of sediment and their ecological significance were deeply discussed. The forms of P in the sediment were defined including soluble and loosely bound P (S/L-P), Al-bound P (Al-P), Fe-bound P (Fe-P), reductant soluble P (RS-P), Ca-bound P (Ca-P), and residual P (RES-P) using the method of selectively sequential extraction. The results indicated that ω (TP) was 421.84-1188.65 mg·kg-1 in the surface sediment. Among the six forms of P, the content of Ca-P was the highest, accounting for more than 40% of TP, followed by the content of Fe-P, accounting for more than 20% of TP. The content of S/L-P was the lowest, which only accounted for approximately 0.4% of TP. The contents of TP and various forms of P in the surface sediments of the downstream area of the Sihe River were higher than those of the upstream area of the river, which was induced by the discharge of industrial wastewater and domestic sewage in the urban areas nearby the downstream portion of the Sihe River. The contents of TP in the upper samples of the two sediment profiles were obviously higher than those in the bottom samples, indicating that the P pollution in the water environment of the Sihe River has been intensifying in recent years. Among all forms of P in the sediment profiles, Ca-P accounted for the largest proportion, followed by Res-P. The correlation analysis results showed that significant correlations were observed between Fe and Fe-P, Al and Al-P, Ca and Ca-P, and TOC and RS-P in the surface sediments; the same correlations had not been found in the sediment profiles. The calculated results of Fe and TP molar ratio indicated that the sediments of the Sihe River could further accumulate P. The percentage of bioavailable P (BAP) in sediment was 25%-50%.
Subject(s)
Phosphorus , Water Pollutants, Chemical , Geologic Sediments/chemistry , Phosphorus/analysis , Rivers/chemistry , Wastewater/analysis , Water Pollutants, Chemical/analysisABSTRACT
The paper introduces professor GAO Shu-zhong's understanding on "seeking yin from yang needling method" and its clinical application on the basis of "qi street" and "four seas" theories. Through professor GAO's clinical practice for years, he integrates and extendes the theories of "seeking yin from yang", "qi street" and "four seas" in Huangdi Neijing (The Yellow Emperor's Inner Classic). In this specific acupuncture method, in reference with the theories of "qi street" and "four seas", acupuncture is exerted on yang part of body, e.g. the back and lumber region to treat the diseases of yin parts, e.g. the chest and abdomen, which is differentiated as yin-yang imbalance in pathogenesis. In order to fully explain the clinical curative effect of "seeking yin from yang needling method", the common diseases in clinic, e.g. the disorders of heart, spleen and stomach systems, as well as the gynecology are taken as examples in the paper.