RDX基PBX的模型、结构、能量及其与感度关系的分子动力学研究

以RDX（环三亚甲基三硝胺）为基、PS（聚苯乙烯）为粘结剂构成PBX（高聚物粘结炸药）的MD（分子动力学）模拟初始模型.比较分别以1根46链节和2根23链节PS置于RDX（001）晶面上的两种（PBX1和PBX2）模型下的MD模拟结果,发现二者的结构、相互作用能和力学性能均很接近.取PBX2进行5种温度（195,245,295,345和395 K）下的NPT系综、MD模拟系统研究,发现随温度依次升高,各体系中RDX引发键N NO2键的最大键长（Lmax）递增,N–N键连的N与N之间的双原子作用能（EN-N）和内聚能密度（CED）递减,与感度随温度升高而增大的实验事实相一致.综合已有工作,对高能复合材料（如PBX和固体推进剂等）的感度理论研究,建议关注其中易爆燃组分在外界刺激下的结构和能量变化,其引发键Lmax和作为引发键强度度量的双原子作用能（如EN-N）,可作为热和撞击感度相对大小的理论判据.     

环三甲撑三硝胺(RDX)结构和性质的DFT研究

环三甲撑三硝胺(RDX)是综合性能好、使用极广的高能炸药。本文用密度泛函理论(DFT)B3LYP方法,取6-31G*基组,求得其分子几何构型、电子结构、IR谱和热力学性质。全优化几何构型和电子结构均具有C3V对称性。在相邻原子之间以NNO2键的Mulliken集居数最小,表明其间电子分布较少,预示其为热解和起爆的引发键。IR谱与实验结果良好相符。计算所得298-1200K的热力学性质,对进一步深入研究RDX的反应和性质有助。     

Identification of Nitro Explosives by Direct Analysis in Real-Time Time-of-Flight Mass Spectrometry

Nitro compounds such as 2,4,6-trinitrotoluene, cyclotrimethylene trinitramine, and pentaerythritol tetranitrate are common ingredients of high explosives found in homeland security threats, minefields, and industrial materials. This study aims at developing a convenient surface analysis method for rapid identification of these compounds by direct analysis in real time coupled with time-of-flight mass spectrometry. The possible ionization mechanisms and fragmentation pathways using the direct analysis in real-time ionization source were developed for each compound based on the ions produced by in-source collision-induced dissociation and acquired by a time-of-flight mass spectrometer. These compounds release nitro groups and form nitroless characteristic fragments with other nitro adducts during in-source collision-induced dissociation processes. The characteristic ion [M?+?C₂H₄N₃O₂]^? produced by cyclotrimethylene trinitramine was observed for the first time to our best knowledge. Direct analysis in real-time time-of-flight mass spectrometry has provided rapid identification of residues from various samples from explosion scenes and, therefore, is a potential powerful screening tool for criminal evidence.     

RDX/AMMO推进剂的分子动力学

利用分子动力学方法研究了含能材料环三亚甲基三硝胺(RDX)、3-叠氮甲基-3-甲基氧丁环(AMMO)和RDX/AMMO推进剂. 结果表明AMMO与RDX(010)面分子之间相互作用最强,其次是(100)和(001)面．用相关函数g(r)描述了RDX和AMMO之间的相互作用．计算了RDX/AMMO推进剂的弹性系数、柯西压、泊松比 等性能．研究结果表明,AMMO的加入能够改善RDX的弹性力学性能,它们的相对改善效应为(100)>(010)>(001)．RDX/AMMO推进剂的能量性能显示,AMMO的加入降低了RDX的比冲,但其仍高于双基推进剂.