为研究靶板材料性能对爆炸成型弹丸(Explosively Formed Projectile,EFP)侵彻靶后破片特性的影响,开展EFP侵彻不同材料靶板(Q235钢、45号钢、装甲钢、2A12铝)后效破片特性试验,采用X光摄影方法观测靶后破片云形态及膨胀尺寸,通过布置多...为研究靶板材料性能对爆炸成型弹丸(Explosively Formed Projectile,EFP)侵彻靶后破片特性的影响,开展EFP侵彻不同材料靶板(Q235钢、45号钢、装甲钢、2A12铝)后效破片特性试验,采用X光摄影方法观测靶后破片云形态及膨胀尺寸,通过布置多层纤维板获得破片散布特性,并对靶后破片进行回收。研究结果表明:在靶板密度一定的情况下,靶板强度主要影响破片云轴向膨胀能力,对径向膨胀能力影响很小;靶后破片环形毁伤区的飞散角位于20°~25°范围内差别不大,但是靶板背面出口崩落会造成靶后破片飞散角出现极大值,随着钢靶强度的增大,靶后破片径向散布增强,破片总数减小,但是大质量段钢破片数量增多;不同强度钢靶产生的钢破片平均尺寸满足Kipp等提出的基于材料流动应力的碎片尺寸模型。展开更多
The structural and dynamical properties of hexafluoroacetylacetone(HFA) and acetylacetone(AA) at the water/supercritical CO2(Sc-CO2) interface at 20 MPa and 318.15 K are investigated by molecular dynamics simulations....The structural and dynamical properties of hexafluoroacetylacetone(HFA) and acetylacetone(AA) at the water/supercritical CO2(Sc-CO2) interface at 20 MPa and 318.15 K are investigated by molecular dynamics simulations.The TIP3P potential is used for water and the EPM2 model is for CO2.The water phase and SC-CO2 phase form a distinct immiscible liquid-liquid interface.The two chelating molecules show interfacial preference.Comparatively,the AA molecules show somewhat more preference for interfacial region,whereas the HFA molecules are preferably near the Sc-CO2 phase.The orientational distribution of the β-diketone molecules and the radial distribution functions between β-diketones and solvents are obtained in order to study the microscopic structural properties of the β-diketones at the water-SC-CO2 interface.It is found that the translational diffusion and rotational diffusion of HFA and AA are obviously anisotropic and decrease as the β-diketone molecules approach the interface.The anisotropic dynamic behavior for the solute molecules is related to the corresponding structural properties.展开更多
文摘为研究靶板材料性能对爆炸成型弹丸(Explosively Formed Projectile,EFP)侵彻靶后破片特性的影响,开展EFP侵彻不同材料靶板(Q235钢、45号钢、装甲钢、2A12铝)后效破片特性试验,采用X光摄影方法观测靶后破片云形态及膨胀尺寸,通过布置多层纤维板获得破片散布特性,并对靶后破片进行回收。研究结果表明:在靶板密度一定的情况下,靶板强度主要影响破片云轴向膨胀能力,对径向膨胀能力影响很小;靶后破片环形毁伤区的飞散角位于20°~25°范围内差别不大,但是靶板背面出口崩落会造成靶后破片飞散角出现极大值,随着钢靶强度的增大,靶后破片径向散布增强,破片总数减小,但是大质量段钢破片数量增多;不同强度钢靶产生的钢破片平均尺寸满足Kipp等提出的基于材料流动应力的碎片尺寸模型。
基金Supported by the National Natural Science Foundation of China (20776066, 20476044) and the Specialized Research Fund for the Doctoral Program of Higher Education of China (20060291002).
文摘The structural and dynamical properties of hexafluoroacetylacetone(HFA) and acetylacetone(AA) at the water/supercritical CO2(Sc-CO2) interface at 20 MPa and 318.15 K are investigated by molecular dynamics simulations.The TIP3P potential is used for water and the EPM2 model is for CO2.The water phase and SC-CO2 phase form a distinct immiscible liquid-liquid interface.The two chelating molecules show interfacial preference.Comparatively,the AA molecules show somewhat more preference for interfacial region,whereas the HFA molecules are preferably near the Sc-CO2 phase.The orientational distribution of the β-diketone molecules and the radial distribution functions between β-diketones and solvents are obtained in order to study the microscopic structural properties of the β-diketones at the water-SC-CO2 interface.It is found that the translational diffusion and rotational diffusion of HFA and AA are obviously anisotropic and decrease as the β-diketone molecules approach the interface.The anisotropic dynamic behavior for the solute molecules is related to the corresponding structural properties.