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A chemical dynamics simulation was performed to study collisions between neon (Ne) atoms and a liquid squalane (2,6,10,15,19,23-hexamethyltetracosane) surface. Ten thousand trajectories were calculated, with an incident energy of 10 kcal/mol, incident polar angle 45° with respect to the surface normal, and random azimuthal angle. The final energy distribution, angular distribution, and impact sites were determined and analyzed. The incident Ne atoms have short residence times on the surface with most atoms successfully scattering within 3−7 ps. Due to thermal fluctuations of the surface, the incident energy is dissipated efficiently, and more than 60% of the initial energy of the Ne atoms is transferred with three or more “kicks” on the surface. For in-plane scattered Ne atoms with a final polar angle of 45°, the energy transfer is 58% ± 8%, which is in good agreement with the experimental value of 60% (J. Chem. Phys. 1993 , 99, 7056). A bimodal energy distribution is observed for both in-plane and out-of-plane scattering, with a much larger Boltzmann component for out-of-plane scattering as compared to in-plane scattering. The incident Ne atoms are found to primarily impinge the terminal methyl groups of the squalane molecules, and such impact probability is correlated with the interfacial structure of the squalane surface. Comparison with previous study of Ne atom scattering off a H-terminated alkyl thiol self-assembled monolayer (H-SAM) surface shows that energy transfer to squalane is less efficient than to the H-SAM, because flexible intermolecular couplings of the alkyl thiol chains of the H-SAM provide efficient dissipation channels to accommodate the incident Ne atom’s energy.

A better understanding of biogeography of Glomeromycota is essential for the conservation of arbuscular mycorrhizal (AM) fungal species and the ecosystem services that they provide worldwide. We examined the spatial dynamics of AM fungi along two slopes (4149 m a.s.l. to the summit at 5033 m a.s.l.) of Mount Mila on the Tibetan Plateau. Our hypothesis was that AM fungal communities at higher elevation would show distinct assemblages with lower diversity in conditions of increasing environmental harshness. A total of 52 operational taxonomic units (OTUs) spanning all four orders were detected and some OTUs were habitat specific. Nearly 30% of the OTUs were new phylotypes, including two family-like clades. Distinct communities of AM fungi were found at the higher elevation, demonstrating potential niche differentiation along the elevation gradient. Elevation patterns of taxon richness/diversity differed between the two transects, decreasing with increasing elevation on the eastern slope and being unimodal (or lacking a pattern) on the western slope. Taken together, our findings provide evidence of a significant spatial structure of AM fungi across the elevation gradient, with the distribution patterns of these fungi regulated simultaneously by the plant communities, soil properties and climatic conditions in this plateau montane ecosystem.

Because of the rapid development of urbanization and industrialization and rise of economy, China has frequently experienced haze pollution. These haze pollution events profoundly affect human health, such as