The heterogeneous Fenton reaction can generate highly reactive hydroxyl radicals (UOH) from reactions between recyclable solid catalysts and H 2 O 2 at acidic or even circumneutral pH. Hence, it can effectively oxidize refractory organics in water or soils and has become a promising environmentally friendly treatment technology. Due to the complex reaction system, the mechanism behind heterogeneous Fenton reactions remains unresolved but fascinating, and is crucial for understanding Fenton chemistry and the development and

Summary Multi‐functional micro RNA s (mi RNA s) are emerging as key modulators of plant–pathogen interactions. Although the involvement of some mi RNA s in plant–insect interactions has been revealed, the underlying mechanisms are still elusive. The brown planthopper ( BPH ) is the most notorious rice ( Oryza sativa )‐specific insect that causes severe yield losses each year and requires urgent biological control. To reveal the mi RNA s involved in rice– BPH interactions, we performed mi RNA sequencing and identified BPH ‐responsive OsmiR396. Sequestering OsmiR396 by overexpressing target mimicry ( MIM 396) in three genetic backgrounds indicated that OsmiR396 negatively regulated BPH resistance. Overexpression of one BPH ‐responsive target gene of OsmiR396, growth regulating factor 8 ( Os GRF 8 ), showed resistance to BPH . Furthermore, the flavonoid contents increased in both the OsmiR396‐sequestered and the Os GRF 8 overexpressing plants. By analysing 39 natural rice varieties, the elevated flavonoid contents were found to correlate with enhanced BPH resistance. Artificial applications of flavonoids to wild type ( WT ) plants also increased resistance to BPH . A BPH ‐responsive flavanone 3‐hydroxylase ( OsF3H ) gene in the flavonoid biosynthetic pathway was proved to be directly regulated by Os GRF 8. A genetic functional analysis of OsF3H revealed its positive role in mediating both the flavonoid contents and BPH resistance. And analysis of the genetic correlation between OsmiR396 and OsF3H showed that down‐regulation of OsF3H complemented the BPH resistance characteristic and simultaneously decreased the flavonoid contents of the MIM 396 plants. Thus, we revealed a new BPH resistance mechanism mediated by the OsmiR396–Os GRF 8–OsF3H–flavonoid pathway. Our study suggests potential applications of mi RNA s in BPH resistance breeding.

The sorption of sodium silicate by synthetic magnetite (Fe 3 O 4 ) at different pH conditions (pH 7-11) and initial silicate concentrations (1 × 10 −3 and 10 × 10 −3 mol L −1 ) was studied using in situ attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. The analysis of infrared spectra of sodium silicate in solution as well as adsorbed on magnetite nano-particles clearly showed the evolution of different silicate species depending on pH and silica concentration. The silicate concentration studied (10 × 10 −3 mol L −1 ) contained polymeric or condensed silicate species at lower pH as well as monomers at high pH, as evident from infrared spectra. Condensation of monomers resulted in an increased intensity of absorptions in the high frequency part (>1050 cm −1 ) of the spectral region, which contains information about both silicate in solution and sorbed silicate viz. 1300 cm −1 -850 cm −1 . In the pH range studied, infrared spectra of sorbed silicate and sorbed silicate during desorption both indicated the presence of different types of surface complexes at the magnetite surface. The sorption mechanism proposed is in accordance with a ligand exchange reaction where both monodentate and bidentate complexes could exist at low surface loading level, the relative proportion of the complexes being due to both pH and concentration in solution. Oligomerization occurred on the magnetite surface at higher surface loading.