主  办：爆炸科学与技术国家重点实验室

      安全与防护协同创新中心
报告题目：Ultra-fast Chemical Reactions of Energetic Materials Explored by Ab Initio MD Simulations

报告人：魏冬青  教授

        上海交通大学

时间：2017年9月20日上午10:00

地点：爆炸科学与技术国家重点实验室二层会议室

个人简介：

魏冬青，上海交通大学长聘教授，交叉科学杂志主编。长期从事交叉科学领域的前沿研究，主要研究方向为生物信息学、计算生物物理学以及高压物理学。最重要的学术成就是首次从理论上证明了铁电液晶的存在和揭示了爆炸反应的微观机理两项成果，均发布在PRL之上。近年来利用经典和量子分子动力学手段对多个复杂分子体系开展了深入的科学研究，如简单炸药热分解分子机制与分子晶体压缩行为，跨膜蛋白小分子调控机制与抗衰老等药物发现，离子跨膜的分子机制以及蛋白质在膜环境下自组织现象，药物代谢酶代谢机理与个性化用药等。获得横山亮次奖，上海交大科学技术奖，上海市优博导师称号。至今发表SCI文章250多篇，主编专著9本。这些工作为国际同行所广泛引用和正面评述，经SCI检索，已累积超过5000次，最高单篇他引约300次， H因子约为47。

报告摘要：

The Car-Parrinello molecular dynamics simulations were employed to investigate thermal decomposition of the solid nitromethane. It is found that it undergoes chemical decomposition at about 2200 K under ambient pressure. The initiation of reactions involves both proton transfer and commonly known C–N bond cleavage. About 75 species and 100 elementary reactions were observed with the final products being H2O, CO2, N2, and CNCNC. It represents the first complete simulation of solid-phase explosive reactions reported to date, which is of far-reaching implication for design and development of new energetic materials.

Molecular dynamics simulations in conjunction with multiscale shock technique (MSST) are performed to study the initial chemical processes and the anisotropy of shock sensitivity of the condensed-phase HMX and RDX under shock loadings applied along the a, b, and c lattice vectors. A self-consistent charge density-unctional tight-binding (SCC-DFTB) method was employed.  the C−H bond dissociation is the primary pathway for HMX decomposition in early stages under high shock loading from various directions. Compared with the observation for shock velocities Vimp = 10 and 11 km/s, the homolytic cleavage of N−NO2 bond was obviously suppressed with increasing pressure.