Revisiting the theoretical prediction of the explosive performance found by the Trauzl test

The Trauzl lead block test allows the determination of the approximate performance of explosives in blasting applications by measuring the volume increase(expansion)that is produced by the detonation of an explosive charge in the cavity of a lead block.In this paper,we reconsider the possibility of interpreting the Trauzl test results in terms of detonation parameters or quantities.The detonation parameters used in the analysis are calculated using the thermochemical code EXPLO5,while the hydrocode AUTODYN is used to simulate the effect of explosive charge density and reaction rate on the results of the Trauzl test.The increase in the volume of the lead block cavity was found to correlate best with the product of the detonation heat and the root of the volume of detonation products.Hydrocode simulation showed that the density of explosive charge and the rate of explosive decomposition affect the dynamics of the interaction of the detonation product and the lead block,and consequently the lead block cavity volume increase.

Prediction of concentration of toxic gases produced by detonation of commercial explosives by thermochemical equilibrium calculations

An adverse effect resulting from explosive mine blasts is the production of toxic nitrogen oxides(NO and NO_(2)) and carbon monoxide(CO).The empirical measurements of the concentration of toxic gases showed that it depends not only on the composition of an explosive and properties of its ingredients but also on several other parameters,such as volume of blasting chamber,explosive charge mass and design,confinement characteristics,surrounding atmosphere,etc.That explains why measured concentrations of toxic gases reported in literature significantly differ.In this paper,we discuss the possibility of theoretical prediction of the concentration of toxic gases by thermochemical equilibrium calculation applying two models:ideal detonation model and deflagration model.It can be demonstrated that thermochemical calculations can provide a good estimation of the measured concentrations and reproduce experimentally obtained effects of additives on the production of toxic gases.It was also found that the ideal detonation model applies to heavily confined explosive charges,while the deflagration model is more suitable for low detonation velocity explosives with light confinement.

Numerical modelling of non-ideal detonation in ANFO explosives applying Wood-Kirkwood theory coupled with EXPLO5 thermochemical code

Ammonium nitrate and fuel oil(ANFO)based explosive is a classic example of non-ideal high explosives.Its detonation is characterized by a strong dependence of detonation parameters on explosive charge diameter,presence and characteristics of confinement,as well as incomplete consumption of explosive at the sonic point.In this work we propose a detonation model based on the Wood-Kirkwood(WK)theory coupled with the thermochemical code EXPLO5 and supplemented with reaction rate models.Our objective is to analyze the validity of the model for highly non-ideal ANFO explosives,with emphasis on effect of reaction rate models.It was found that both single-step and two-step pressure-based models can be calibrated to reproduce experimental detonation velocity-charge radius data of ANFO at radii significantly above the failure radius(i.e.for D/D_(id)>~0.6).Single-step pressure-based model,with the pressure exponent equal to 1.4,proved to be the most accurate,even in the vicinity of the failure radius.The impact of the rate models is most evident on temporal(and spatial)distribution of flow parameters in detonation driving zone,especially when it comes to the conversion and width of detonation driving zone.

SPACE CHEMISTRY RESEARCHES IN CHINA DURING 2000-2001

Over the past two years, significant progress in space chemistry has been made in China. The research fields include meteorites, pre-solar materials, science researches of the moon, effects of the space debris on space environment, and heterogeneity of the Earth. Chinese Lunar Exploration Project Some studies are also dedicated to one important space mission "Chinese Lunar Exploration Project". In this paper, the main achievements are outlined, and some concepts and hypotheses are briefly revised.

高能液固混合燃料配方优化及毁伤分析

为筛选优化高能燃料空气炸药(FAE)的配方组分,以石油醚、环氧丙烷和乙醚作为液体燃料,硝酸异丙酯和硝基甲烷作为液体敏化剂,金属铝粉作为固体组分,通过EXPLO5计算软件比较了不同配比FAE的爆炸压力和爆炸温度,并在无约束条件下进行了液体和液固FAE配方的云雾爆轰实验,对爆炸场、温度场等参数进行了毁伤效果分析,并量化评估了各体系的热毁伤、超压毁伤的效果。结果表明,石油醚、环氧丙烷与硝酸异丙酯混合的混合液体FAE,在石油醚质量占比55%~70%条件下,爆轰性能上表现较优。液固混合FAE中液固比例为1∶1条件下具有较良好的爆轰性能,并在无约束云雾分散实验中表现出最佳的云雾分散状态。两种体系的FAE配方在1 kg的二次起爆药量下云雾爆轰可以稳定反应,能达到爆轰状态,且在毁伤能力均具有较优效果。

试论文体革新的必然性

以20世纪80年代以来中国文体革新现象为切入点,以诗歌的文体变革和创新为侧重点,历览古今文体变革史,论述了文体的变革和创新,是我们时代最需要的文学创新意识和最重要的内驱力,是文学在新的时期不断创新和发展的必然趋势:文体总是从少到多,由简而繁,旧的文体不断变革,新的文体不断创造。

大跨度桥梁悬臂施工技术探究

大跨度桥梁的悬臂施工是一个复杂的施工过程,各施工阶段的结构受力会受其他条件的变化而发生变化,有很大的不确定性。本文对大跨度桥梁的悬臂施工技术进行了一些探究。

我国保障性住房制度建设探析

保障性住房不仅解决了城镇居民的住房问题还为中低收入的家庭提供了一定的住房机会。现如今我国的保障性住房建设进入到一个全新的发展时期，但是我国的保障性住房在建设的过程中还存在着很多的问题，我们需要一一地对其进行研究、改进。

H.S.E

On May 11th, 2007 explosion happened at the nitration section in the TDI(toluene diisocyanate) workshop of Cangzhou Dahua TDI Co. Ltd, a subsidiary of Cangzhou Dahua Co. Ltd. (Cangzhou Dahua, SH:600230) located in Dazidian, Cangzhou, Hebei province. The accident has caused 5 death and more than 80 injuries. Relevant oil tanks. pipelines and production facili-