Ram-Chem (China)

• Obtained high-precision rate constants and branch ratios for the hydrogen abstraction reactions of methanol by amino radicals. • Found the strong high-frequency anharmonicity in the transition states and its major impact on the kinetics. • Evaluated the uncertainties of different kinetics effects in the reaction rates. The combustion of the ammonia/methanol blends has attracted much attention due to the potential to reduce carbon emissions. Some previous research had pointed out the importance of involving cross-reactions in the combustion simulation of the ammonia/methanol blends, especially the hydrogen abstraction reaction of amino (NH 2 ) radicals and methanol. Therefore, we carried out a detailed kinetics study of the reaction of NH 2 and methanol in a wide temperature range. The potential energy surface was calculated using the high-level W3X-L//M08-HX/MG3S method, and the specific-reaction-parameter (SRP) scaling factors of frequencies were calculated and used to correct the stronger high-frequency anharmonicity in the transition states than the reactants. The canonical variational transition state theory was used to calculate the rate constants over the temperature range of 200–2000 K, with multi-structural torsional anharmonicity correction and the small curvature tunneling approximation (MS-CVT/SCT). The results show that the stronger high-frequency anharmonicity of the transition states significantly affects the barrier height and thereby causes a deviation factor of 17.5 at 200 K and 1.8 at 2000 K in the prediction of the reaction rates on -OH site of CH 3 OH and a deviation factor of 7.5 at 200 K and 1.2 at 2000 K in the branching ratios on -CH 3 site of CH 3 OH in the reaction of CH 3 OH and NH 2 radicals. In addition, the variational effect and the multi-structural torsional anharmonicity cannot be ignored in the reaction of CH 3 OH and NH 2 radicals. These results can also provide references for evaluating the uncertainty in the reaction kinetics calculations of NH 2 radicals with other alcohol fuels.

Road traffic, railway and industrial noise sources are main challenges in maintaining satisfying acoustical environment for living habitat in Hong Kong. Ventilation-enabling sound insulation devices has been introduced to Hong Kong residential development in the aim of striking a good balance between indoor ventilation and sound insulation. In the form of windows and balconies, the sound insulation devices were applied to mitigate the potential road traffic, railway, and fixed noise impacts. The sound insulation performances of the devices were verified in a 1:1 mock-up test and indicated by in-out difference, which contributed from the outdoor and indoor noise levels. The in-out difference of the sound insulation devices varies with the adopted spectrum, depending on flat layout configurations. The enhancing performance of applied acoustic material to the sound insulation devices, and that of applied acoustic fin adjacent to the devices are also studied.

Abstract Designing and constructing novel topological all‐solid‐state polymer electrolyte (SPE) matrices can improve the ionic conducting ability of the prepared SPEs compared with the linear ones. Here, we construct a novel topological polymer electrolyte matrix using triphenylene as core and block poly(methyl methacrylate)‐poly(poly[ethylene glycol] methyl ether methacrylate) as arm. Specifically, the arm is attached onto the core via sequential atom transfer radical polymerization. The molecular weight of the polymers is well controlled via adjusting the inventory rating of monomers, the optimal SPE obtained via solution casting has an ambient temperature ionic conductivity of 3.69 × 10−5 S cm−1, which is higher than typical linear poly(ethylene oxide)‐based SPE (usually 10−6–10−8 S cm−1). The electrochemical performance is further improved through adding given contents of graphene‐oxide into the SPE. Thus, we believe, through molecular designing and the widely used composite tactics, new class of electrolytes with high‐electrochemical performance for all‐solid‐state Li‐ion batteries can be developed.