Optimization calculations of 209 polychlorinated biphenyls （PCBs） were carried out at the B3LYP/6-31G^＊ level. It was found that there is significant correlation between the Cl substitution position and some struct...Optimization calculations of 209 polychlorinated biphenyls （PCBs） were carried out at the B3LYP/6-31G^＊ level. It was found that there is significant correlation between the Cl substitution position and some structural parameters. Consequently, Cl substitution positions were taken as theoretical descriptors to establish a novel QSPR model for predicting –lgSw of all PCB congeners. The model achieved in this work contains four variables, of which r^2 = 0.9527, q^2 = 0.9490 and SD = 0.25 with large t values. In addition, the variation inflation factors （VIFs） of variables in this model are all less than 5.0, suggesting high accuracy of the –lgSw predicting model. And the results of cross-validation test and method validation also show that the model exhibits optimum stability and better predictive capability than that from the AM1 method.展开更多
采用溶剂-非溶剂的方法,通过加入不同的晶形控制剂制备超细CL-20,并对晶形控制剂的种类和用量、加料方式等因素进行了分析。结果表明,晶形控制剂的种类、用量及样品溶剂加料方式严重地影响着超细CL-20的晶形。对于2.0 g CL-20原料,采用3...采用溶剂-非溶剂的方法,通过加入不同的晶形控制剂制备超细CL-20,并对晶形控制剂的种类和用量、加料方式等因素进行了分析。结果表明,晶形控制剂的种类、用量及样品溶剂加料方式严重地影响着超细CL-20的晶形。对于2.0 g CL-20原料,采用3.5 mL质量浓度2%聚乙烯醇类化合物(PV)晶形控制剂,所得到的超细粉末晶形大多为块状,晶体粒径最小可达到1μm;采用6.5 mL质量浓度5%聚氧乙烯醚类化合物(PT)晶形控制剂,所得到的超细粉末晶形也大多为块状,晶体粒径最小可达到2μm。采用喷壶方式加料,使用6.5 mL质量浓度5%PT晶形控制剂可使晶形呈椭圆形,晶体粒径最小可达到1μm,细化后的CL-20热敏感性更高,晶型仍为ε型。展开更多
以ε-CL-20(六硝基六氮杂异伍兹烷)为主体炸药,三元乙丙橡胶(EPDM)为胶粘剂,采用喷雾干燥法制备了ε-CL-20基PBX(聚合物粘接炸药)。研究结果表明:通过喷雾干燥法可使EPDM成功包覆在CL-20晶体表面,制得的包覆产物为ε-CL-20/EPDM复合炸药...以ε-CL-20(六硝基六氮杂异伍兹烷)为主体炸药,三元乙丙橡胶(EPDM)为胶粘剂,采用喷雾干燥法制备了ε-CL-20基PBX(聚合物粘接炸药)。研究结果表明:通过喷雾干燥法可使EPDM成功包覆在CL-20晶体表面,制得的包覆产物为ε-CL-20/EPDM复合炸药;与细化CL-20相比,ε-CL-20/EPDM的撞击感度明显降低,包覆样品的特性落高(H50)值从25.12 cm升至41.36 cm,表观活化能由182.58 k J/mol增至230.24 k J/mol,热爆炸临界温度由244.18℃增至245.60℃,说明ε-CL-20/EPDM复合炸药的热稳定性更好。展开更多
基金This work was supported by the 973 National Basic Research Program of China (2003CB415002)the China Postdoctoral Science Foundation (No. 2003033486)
文摘Optimization calculations of 209 polychlorinated biphenyls （PCBs） were carried out at the B3LYP/6-31G^＊ level. It was found that there is significant correlation between the Cl substitution position and some structural parameters. Consequently, Cl substitution positions were taken as theoretical descriptors to establish a novel QSPR model for predicting –lgSw of all PCB congeners. The model achieved in this work contains four variables, of which r^2 = 0.9527, q^2 = 0.9490 and SD = 0.25 with large t values. In addition, the variation inflation factors （VIFs） of variables in this model are all less than 5.0, suggesting high accuracy of the –lgSw predicting model. And the results of cross-validation test and method validation also show that the model exhibits optimum stability and better predictive capability than that from the AM1 method.
文摘以ε-CL-20(六硝基六氮杂异伍兹烷)为主体炸药,三元乙丙橡胶(EPDM)为胶粘剂,采用喷雾干燥法制备了ε-CL-20基PBX(聚合物粘接炸药)。研究结果表明:通过喷雾干燥法可使EPDM成功包覆在CL-20晶体表面,制得的包覆产物为ε-CL-20/EPDM复合炸药;与细化CL-20相比,ε-CL-20/EPDM的撞击感度明显降低,包覆样品的特性落高(H50)值从25.12 cm升至41.36 cm,表观活化能由182.58 k J/mol增至230.24 k J/mol,热爆炸临界温度由244.18℃增至245.60℃,说明ε-CL-20/EPDM复合炸药的热稳定性更好。
