[Spatial Variation of Soil Heavy Metals in Lin'an City and Its Potential Risk Evaluation].

Urban soil is an important part of the urban ecosystem, which is strongly correlated with human health and life quality. In this study, Lin'an city was chosen as a typical small city to study the spatial variation and distribution of heavy metals in urban soils and their pollution characteristics using multivariate analysis, geostatistics, and GIS techniques. A total of 62 soil samples were collected from the study areas.

Silica hybrid particles with nanometre polymer shells and their influence on the toughening of polypropylene.

Colloidal silica particles were synthesized by the sol-gel process and then modified with 3-methacryloxypropyltrimethoxysilane (γ-MPS) to induce vinyl groups on the surface of the silica particles. By means of in situ emulsion copolymerization of methyl methacrylate (MMA) and butyl acrylate (BA), a series of core-shell silica hybrid particles with nanometre poly(MMA-co-BA) shells were fabricated, which were subsequently compounded with isotactic polypropylene (PP) in the molten state. Upon increasing the feed silica : monomer ratio from 1 : 1 to 4 : 1, the poly(MMA-co-BA) shell thickness on the silica core decreased from 50 nm to 10 nm.