[Source Apportionment and Potential Ecological Risk Assessment of Soil Heavy Metals in Typical Industrial and Mining Towns in North China].

To understand the status of heavy metals in soils of typical industrial and mining towns and quantitatively analyze the potential sources, the contents of seven heavy metals (Cd, As, Pb, Cr, Cu, Ni, and Zn) in 150 surface soils in Xuanhua District, Zhangjiakou City, Hebei Province were collected and examined. The geoaccumulation index and potential ecological risk index methods were used to evaluate the heavy metal pollution status and potential ecological risk. Principal component analysis (PCA) and the positive matrix factorization (PMF) model were used to comprehensively analyze the pollution sources of seven heavy metals, and geostatistics was used to identify the high contribution areas of potential sources.

Nanofluidic diode based on branched alumina nanochannels with tunable ionic rectification.

In this work, the synthetic alumina nanochannels with bi-, tri-, and tetra-branched geometry structures exhibited ionic current rectifications with nonlinear I-V curves. Such diode performance of the branched alumina nanochannel is mainly dependent on the cooperative asymmetry of the branched structure and the surface-charge distribution on inner walls. By regulating the geometry, electrolyte pH, and solution concentration, the tunable ionic rectification properties are effectively obtained including both the rectification ratios and the rectifying direction that were deduced from the converted ion selectivity.

Synthesis, structure, and photoelectronic effects of a uranium-zinc-organic coordination polymer containing infinite metal oxide sheets.

The hydrothermal reaction of ZnUO2(OAc)4.7H2O with pyridine-2,3-dicarboxylic acid gives rise to a novel uranium-zinc-organic coordination polymer containing infinite U-O-Zn double sheets and organic ligands. Thermal and photoelectrochemical analyses indicate that the coordination polymeric compound not only has a high thermal stability but also exhibits interesting photoelectronic properties.