炸药水中爆炸冲击因子的新型计算方法

针对水中爆炸冲击因子在近场范围内的一些不足,利用水中爆炸冲击波的最大峰值压力与正相冲量的乘积推导了冲击因子的表达式。通过水中爆炸实验,得到了几种典型炸药的冲击波参数及其相似方程。利用该公式计算了水中爆炸冲击因子及其装药指数,并与基于平面波的水下爆炸冲击因子进行了对比。结果表明：冲击因子中的装药指数n＝0.5不仅适合所有以TNT为基本组分的炸药,也适合于RDX、HMX基的炸药。在修正冲击波形状的基础上,由峰值压力与冲量的乘积推导的冲击因子计算公式,从冲击波的毁伤作用的角度表述了水中爆炸冲击因子的物理意义,在计算近场冲击因子时具有更高的准确性。

     

含铝炸药水下爆炸性能的实验研究

对RS211、HL-1、HL-2这3种含铝炸药和TNT炸药进行了水下爆炸实验,测量了4种炸药水下爆炸冲击波压力剖面和气泡脉动周期,获得了4种炸药水下爆炸冲击波的峰值超压、冲量、能量和气泡能。实验结果表明,在所研究的范围内,与TNT炸药相比,含铝炸药的冲击波能量有明显增加,约为TNT炸药的1.20～1.35倍,气泡能有显著增加,约为TNT炸药的1.50～2.30倍,表明在炸药中加入铝粉对于提高炸药水中爆炸威力是有益的。     

Non‐Isothermal Decomposition Kinetics,Specific Heat Capacity and Adiabatic Time‐to‐explosion of a Novel High Energy Material: 1‐Amino‐1‐Methylamino‐2,2‐Dinitroethylene (AMFOX‐7)

A novel high energy material, 1‐amino‐1‐methylamino‐2,2‐dinitroethlyene (AMFOX‐7), was synthesized by the reaction of 1,1‐diamino‐2,2‐dinitroethylene (FOX‐7) and methylamine aqueous solution in N‐methyl pyrrolidone at 80°C. The thermal behavior and non‐isothermal decomposition kinetics of AMFOX‐7 were studied with DSC and TG/DTG methods. The kinetic equation of thermal decomposition reaction can be expressed as: $ {\rm d\alpha /d}T = \frac{{10^{21.03}}}{{\rm \beta}}\frac{3}{2}\left({1 - {\rm \alpha}} \right)\left[{- 1{\rm n}\left({{\rm 1} - {\rm \alpha}} \right)} \right]^{\frac{1}{3}} \exp \left({- 2.292 \times 10^5 {\rm /}RT} \right) A novel high energy material, 1‐amino‐1‐methylamino‐2,2‐dinitroethlyene (AMFOX‐7), was synthesized by the reaction of 1,1‐diamino‐2,2‐dinitroethylene (FOX‐7) and methylamine aqueous solution in N‐methyl pyrrolidone at 80°C. The thermal behavior and non‐isothermal decomposition kinetics of AMFOX‐7 were studied with DSC and TG/DTG methods. The kinetic equation of thermal decomposition reaction can be expressed as: $ {\rm d\alpha /d}T = \frac{{10^{21.03}}}{{\rm \beta}}\frac{3}{2}\left({1 - {\rm \alpha}} \right)\left[{- 1{\rm n}\left({{\rm 1} - {\rm \alpha}} \right)} \right]^{\frac{1}{3}} \exp \left({- 2.292 \times 10^5 {\rm /}RT} \right) $. The critical temperature of thermal explosion of AMFOX‐7 is 244.89°C. The specific heat capacity of AMFOX‐7 was determined with micro‐DSC method and theoretical calculation method, and the standard molar specific heat capacity is 199.39 J·mol^?1·K^?1 at 298.15 K. Adiabatic time‐to‐explosion of AMFOX‐7 was also calculated to be 215.41 s. AMFOX‐7 has higher thermal stability than FOX‐7.     

梯度蜂窝夹芯板在爆炸荷载作用下的动力响应

利用弹道冲击摆锤系统对分层梯度蜂窝夹芯板在爆炸荷载下的动力响应进行了实验研究,分析了梯度蜂窝夹芯板在爆炸荷载作用下的变形失效模式,并与传统非梯度蜂窝夹芯板的抗爆性能做了对比。通过一维应力波理论,分析了应力波在梯度芯层中的传播规律。应力波透射系数在梯度试件中比非梯度芯层中小,而且相对密度递减的芯层组合有最小的应力波透射系数。综合考虑结构变形失效模式,后面板挠度,芯层压缩量以及应力波传播特点得到:分层梯度蜂窝夹芯板的抗爆性能明显优于传统的非梯度夹芯板,在所研究的荷载范围内,芯层相对密度从大到小排列试件的抗爆性能相对较好。     

国际地下实验室发展综述

地下实验室是开展粒子物理学、天体物理学及宇宙学等领域一些重大基础性前沿课题的重要研究场所和良好的低本底环境,建设和发展地下实验室对于一个国家的基础科学研究具有重要科学意义.目前,国际上许多国家都已经建立起地下实验室,而中国一直没有很好的地下实验室,特别是极深地下实验室.2009年,清华大学与二滩水电开发有限责任公司开展战略合作,利用锦屏山隧道建立中国首个世界最深的地下实验室--中国锦屏地下实验室(China Jinping Underground Laboratory,CJPL),并于2010年12月12日正式启用.中国锦屏地下实验室的建成,标志着中国已经具备开展物理学重大基础前沿科学研究的自主地下实验平台,对于推动我国相关领域的重大基础前沿课题的自主研究意义重大.文章对国际上一些重要地下实验室的情况进行了介绍,并对中国锦屏地下实验室的基本情况进行了介绍.     

沉积粉尘的激波点火

采用瞬态阴影技术及红外光电传感器技术实验研究了沉积玉米粉的激波点火过程，并对此进行了理论分析。实验与理论分析结果表明，激波掠射沉积粉尘床后，粉尘颗粒先上扬到一定高度后才点火，颗粒的点火延迟时间与激波波前马赫数、气相氧气含量等因素有关。另外，沉积粉尘的激波点火延迟时间比相同条件下的悬浮粉尘激波点火延迟时间长。     

飞秒强激光作用下Ar原子团簇离子能谱计算

研究了飞秒强激光与Ar原子团簇相互作用时的电离机制及库仑爆炸过程,建立了一个简化的模型计算相互作用产生的离子能谱,计算结果与实验结果较为吻合,可以较好地解释离子能谱高能端的主要特征。     

ELECTRON GUN FOR LARGE ORBIT GYROTRON (LOG) WITH DECREASED INFLUENCE OF CATHODE PLASMA ON ELECTRON BEAM PROPERTIES

High power Large Orbit Gyrotron (LOG) [1] is now under development at FIR FU. First version of this device was recently manufactured and then assembled with power supply ETIGO-IV [2]. Results of preliminary tests of electron-optic system are presented. The conditions when stableflat form of current pulse realized are discussed. Analytical estimations of cathode-anode distance to achieve small influence of cathode plasma during high voltage (HV) pulse are performed. Two new electron gun versions with decreased influence of the cathode plasma on its impedance and pulse form are suggested and optimized. New optimal magnetic field distributions are found. First gun has quiasi-flat cathode configuration near the anode diaphragm and provides operating current about 60 A. Second one uses blade cathode with operating current about 30 A. Beam quality for both guns is suitable for LOG operation.     

Nonstationary wave turbulence

Summary Nonstationary regimes of the wave turbulence evolution are considered in the framework of isotropic kinetic equation. It is predicted analytically and confirmed by numerical experiment that there is a class of wave systems in which any initial distribution of the turbulence energy ink-space comes into a universal, Kolmogorovtype spectrum in a finite time. Before and after the formation of the Kolmogorov spectrum, two different self-similar regimes of evolution occur: the first one is responsible for explosively forming the universal spectrum and the second one determines energy dissipation.     

岩石爆破的粉碎区及其空腔膨胀

本文根据爆炸冲击波的理论分析,讨论了柱形装药和球形装药的粉碎区半径、炮孔近区的压缩比、爆破空腔及其空腔的发展时间。通过分析,给出柱形装药的爆炸近区参数。计算结果表明:2号铵梯岩石炸药柱形装药在岩石介质中产生的粉碎区半径一般是炮孔半径的1.65～3.05倍,球装药在岩石介质中产生的粉碎区半径是球形装药半径的1.28～1.75倍;柱形装药在孔壁处的冲击波波长与炮孔半径属于同一量级;粉碎区内的平均压缩比为1.05～1.10。