Electronic Structure of AIB2-type U-Si Binary Intermetallic Compounds by Hybrid Density Functional Calculations

In this paper the electronic structure of A1B2-type USi2 has been explored using DFT, DFT＋U and hybrid functional （HSE） methods. It reveals that c/a has great effect on the electronic structure, particularly theforbitals, and there exists strong hybridization between the Si-p and U-d orbitals in A1B2-type USi2. These calculations uncover that there exists similarities on the crystal structure and the electronic structure between AIB2-type USi2 and UaSis. Present calculations provide a further insight on the U3Si5, a heavy-fermion system.

Experimental study of photooxidation products of ethylbenzene

Smog chamber experiments were performed to investigate the composition of products formed from photooxidation of aromatic hydrocarbon ethylbenzene. Vacuum ultraviolet photoionization mass spectrometer and aerosol time-of-flight mass spectrometer were used to measure the products in the gas and particle phases in real-time. Experimental results demonstrated that ethylphenol, methylglyoxal, phenol, benzaldehyde, and 2-ethylfurane were the predominant photooxidation products in both the gas and particle phases. However, there were some differences between detected gas phase products and those of particle phase, for example, 2-ethylfurane, ethylglyoxylic acid, nitroethylbenzene, 3,4-dioxopentanal and ethyl-nitrophenol were only existing in the particle-phase. The possible reaction mechanisms leading to these products were also discussed and proposed.

A VUV photoionization mass spectrometric study on the OH-initiated photooxidation of isoprene with synchrotron radiation

The gas-phase organic compounds resulting from OH-initiated photooxidation of isoprene have been investigated on-line by VUV photoiortization mass spectrometry based on synchrotron radiation for the first time. The photoionization efficiency curves of the corresponding gaseous products as well as the chosen standards have been deduced by gating the interested peaks in the photoionization mass spectra while scanning the photon energy simultaneously, which permits the identification of the pivotal gaseous products of the photooxidation of isoprene, such as formaldehyde （10.84 eV）, formic acid （11.38 eV）, acetone （9.68 eV）, glyoxal （9.84 eV）, acetic acid （10.75 eV）, methacrolein （9.91 eV）, and methyl vinyl ketone （9.66 eV）. Proposed reaction mechanisms leading to the formation of these key products were discussed, which were completely consistent with the previous works of different groups. The capability of synchrotron radiation photoionization mass spectrometry to directly identify the chemical composition of the gaseous products in a simulation chamber has been demonstrated, and its potential application in related studies of atmospheric oxidation of ambient volatile organic compounds is anticipated.