基于性能的抗震设计理论（Performance Based SeismicDesign，PBSD）将成为未来抗震设计发展的方向。本文详细阐述了基于性能的杭震设计理论的基本概念和发展过程，总结了其研究内容和设计方法，并据此提出了目前基于性能的抗震设计理...基于性能的抗震设计理论（Performance Based SeismicDesign，PBSD）将成为未来抗震设计发展的方向。本文详细阐述了基于性能的杭震设计理论的基本概念和发展过程，总结了其研究内容和设计方法，并据此提出了目前基于性能的抗震设计理论研究中存在的主要问题和进一步研究的方向。展开更多
Micro-alloying design of wrought magnesium(Mg) alloys is an important strategy to achieve high mechanical properties at a low cost. In the last two decades, significant progress has been made from both theory and expe...Micro-alloying design of wrought magnesium(Mg) alloys is an important strategy to achieve high mechanical properties at a low cost. In the last two decades, significant progress has been made from both theory and experiment. In the present review, we try to summarize recent advances in micro-alloying design of wrought Mg alloys from both theoretical and pragmatic perspectives, and provide fundamental data required for establishing the relationship between chemical composition and mechanical properties of Mg alloys. We start with theoretical attempts for understanding the mechanical properties of Mg alloys at different scales, by involving first principle calculations,molecular dynamics, cellular automata, and crystal plasticity. Then, the role of alloying elements is discussed for a series of promising Mg alloys such as Mg-Al, Mg-Zn, Mg-RE(rare-earth element), Mg-Sn, and Mg-Ca families.Potential challenges in the micro-alloying design of Mg alloys are highlighted at the end. The review is expected to provide helpful guidance for the intelligent design of novel wrought Mg alloys and inspire more innovative ideas in this field.展开更多
The insensitive property of explosives containing pyfidine is combined with the high energy of nitramine explosives, and the concept of new nitramine explosives containing pyridine is proposed, into which nitramine gr...The insensitive property of explosives containing pyfidine is combined with the high energy of nitramine explosives, and the concept of new nitramine explosives containing pyridine is proposed, into which nitramine group with N-N bonds is intro- duced as much as possible. Based on molecular structures of nitramine compounds containing pyridine, density functional the- ory （DFT） calculation method was applied to study designed molecules at B3LYP/6-31＋G（d） level. The geometric and elec- tronic structures, density, heats of formation （HOF）, detonation performance and bond dissociation energies （BDE） were investigated and comparable to 1,3,5-trinitro-l,3,5-triazinane （RDX） and 1,3,5,7-tetranitro-1,3,5,7-tetrazocane （HMX）. The simulation results reveal that molecules B and D perform similarly to traditionally used RDX. Molecule E outperform RDX, with performance that approach that of HMX and may be considered as potential candidate of high energy density compound （HEDC）. These results provide basic information for molecular design of novel high energetic density compounds.展开更多
基金the financial supports from the National Natural Science Foundation of China (Nos. U1764253, U2037601, 52001037, 51971044, 52101126)the National Defense Basic Scientific Research Program of China, China Postdoctoral Science Foundation (No. 2021M700566)+3 种基金the Natural Science Foundation of Chongqing, China (No. cstc2019jcyjmsxm X0234)Chongqing Science and Technology Commission, China (No. cstc2017zdcyzdzx X0006)Chongqing Scientific and Technological Talents Program, China (No. KJXX2017002)Qinghai Science and Technology Program, China (No. 2018-GX-A1)。
文摘Micro-alloying design of wrought magnesium(Mg) alloys is an important strategy to achieve high mechanical properties at a low cost. In the last two decades, significant progress has been made from both theory and experiment. In the present review, we try to summarize recent advances in micro-alloying design of wrought Mg alloys from both theoretical and pragmatic perspectives, and provide fundamental data required for establishing the relationship between chemical composition and mechanical properties of Mg alloys. We start with theoretical attempts for understanding the mechanical properties of Mg alloys at different scales, by involving first principle calculations,molecular dynamics, cellular automata, and crystal plasticity. Then, the role of alloying elements is discussed for a series of promising Mg alloys such as Mg-Al, Mg-Zn, Mg-RE(rare-earth element), Mg-Sn, and Mg-Ca families.Potential challenges in the micro-alloying design of Mg alloys are highlighted at the end. The review is expected to provide helpful guidance for the intelligent design of novel wrought Mg alloys and inspire more innovative ideas in this field.
基金supported by the NSAF Foundation of National Natural Science Foundation of China and China Academy of Engineering Physics(11076017)
文摘The insensitive property of explosives containing pyfidine is combined with the high energy of nitramine explosives, and the concept of new nitramine explosives containing pyridine is proposed, into which nitramine group with N-N bonds is intro- duced as much as possible. Based on molecular structures of nitramine compounds containing pyridine, density functional the- ory （DFT） calculation method was applied to study designed molecules at B3LYP/6-31＋G（d） level. The geometric and elec- tronic structures, density, heats of formation （HOF）, detonation performance and bond dissociation energies （BDE） were investigated and comparable to 1,3,5-trinitro-l,3,5-triazinane （RDX） and 1,3,5,7-tetranitro-1,3,5,7-tetrazocane （HMX）. The simulation results reveal that molecules B and D perform similarly to traditionally used RDX. Molecule E outperform RDX, with performance that approach that of HMX and may be considered as potential candidate of high energy density compound （HEDC）. These results provide basic information for molecular design of novel high energetic density compounds.
