The notion of a U-exact sequence is generalization the exact sequence. In this paper, we introduce rough in group an approximation space. Furthermore, provide properties group.

A newly synthesized alkyl phosphinic acid resin (APAR) was used for on-line preconcentration of trace rare earth elements (REES, lanthanides including yttrium) and then determined by inductively coupled plasma mass spectrometry. REEs in seawater could be on-line concentrated on the APAR packed column (4.6mm i.d.x50mm in length), and eluted from the column with 0.5mL 0.1molL(-1) nitric acid with...

Recently, the worldwide supply of rare earth element (REE) resources will be severely restricted. On the other hand, coal fly ash particles emitted from coal-fired electric power plants contain relatively high concentrations of REEs. The contents of REEs in coal fly ash are regularly several hundreds of ppmw. In order to extract and recover REEs from coal fly ash particles, as a first step, we ...

In the present study, bioaccumulation of REEs in Zea mays L. (corn plant) has been analyzed. The role of Rare Earth Element (REEs) in physiology and biochemistry of corn plant have been studied. Physiological characters like peroxidase (POD) and superoxide dismutase (SOD) activities, biochemical analysis of chlorophyll, carotenoids and phenol contents have also been carried out. The plant growt...