膨化硝酸铵自敏化理论基础与实验研究

膨化硝酸铵自敏化理论是基于热点学说,在广泛研究敏化手段情况下,它是对国内外传统方法的突破,它把微气泡通过膨化技术植入膨化硝铵炸药中,达到自敏化创新设计。实验研究了膨化硝酸铵晶体、结构、微气泡分布等,对自敏化理论设计成功给予进一步证实。     

硝酸铵自敏化的基本原理和技术途径

低成本和优性能的无梯粉状硝铵炸药是工业炸药发展的趋势之一，其中硝酸铵自敏化是关键的技术途径。文中基于爆炸理论和化学原理，对硝酸铵自敏化的可能途径进行了分析和论述，主要有微气泡自敏化、晶格缺陷自敏化、晶变自敏化、晶体活化敏化和表面自敏化等。     

硝酸铵膨化技术及应用

硝酸铵膨化技术是一创新技术,创新设计的指导思想是硝酸铵自敏化,硝酸铵自敏化的提出是对国内外传统方法的突破。实施自敏化的技术途径是硝酸铵的膨化,其实质是表面活性技术在粉状炸药中的应用,是一个强制析晶的物理化学过程。文章重点讨论了硝酸铵膨化机理及膨化硝酸铵的技术特征,显示其独特的优点。硝酸铵膨化技术主要应用是岩石膨化硝铵炸药,给出了岩石膨化硝铵炸药的爆炸与物理特征数据,并与其它工业炸药做了比较。同时也推广应用在煤矿许用型炸药中。     

浅谈提高岩石膨化硝铵炸药密度的方法

由于膨化硝酸铵具有大量的敏化微气泡,使岩石膨化硝铵炸药的密度降低,相应的单位体积装药量少,炮孔的利用率低。文章从岩石膨化硝铵炸药的组成及生产工艺入手,对提高岩石膨化硝铵炸药密度的一些常见方法进行了探讨。添加的材料A具有原料来源广,价格与硝酸铵相当,加入工艺简单,可实现连续化生产,生产过程安全性好,能显著提高岩石膨化硝铵炸药密度等特点。     

膨化硝酸铵的微观结构研究

文章对膨化硝酸铵、普通硝酸铵进行晶形电镜扫描,研究了其孔径与孔容分布、粒径分布、比表面积测定及DSC实验,揭示了膨化硝酸铵的微观结构,说明了膨化硝酸铵具备自敏化的结构特征.     

膨化硝铵炸药中添加乳化基质的研究

通过表面活生剂对硝酸铵进行处理制得的自敏化膨化硝酸铵,应用这种膨化硝酸铵作氧化剂和敏化剂,再辅助以乳化基质制得的复配型炸药能进一步提高岩石膨化硝铵炸药的爆破效果。试验结果表明,这种炸药具有良好的使用性能。     

测试密度对膨化硝酸铵微观结构表征的影响

文章利用NOVA1000比表面积测试仪,测试了膨化硝酸铵在堆积密度和晶体密度下的孔径分布、累积孔面积和累积孔体积、比表面积以及孔容等微观结构参数,并比较了两种密度下表征膨化硝酸铵的微观结构参数的差异.结合理论分析和测试数据可知,利用硝酸铵的晶体密度进行测试可以更精确地表征膨化硝酸铵的微观结构,避免了因测试堆积密度而导致的测试误差,能够更好地理解硝酸铵的自敏化理论.     

文摘

具有高抗水性的炸药组成;多孔粒状硝酸铵和乙醇或甲醇混合物的爆炸特性值;爆破炸药及其制造;膨化硝酸铵自敏化理论基础与实验研究;LRH—A型乳化炸药中用的复合剂     

膨化硝铵炸药密度添加剂的研究

通过表面活性剂对硝酸铵进行处理,制取敏化膨化硝酸铵,存在装药密度偏低、威力相对减少的现象.添加密度添加剂能解决此问题,并能提高爆破使用效果.     

多元易发泡型复合乳化剂乳化炸药的制备

文章论述了一种多元易发泡型复合乳化剂,它含水溶性和油溶性两种类型的乳化剂,能将内相中硝酸铵溶液极个别硝酸铵分子外移至外相,与亚硝酸钠水溶液NO2相遇后,即产生气泡（N2）,使乳胶基质敏化成乳化炸药,消除了化学敏化中二元敏化、后效及混合不均匀的问题。     

基于多相流的LCM工艺气泡生成仿真

分析了液体模塑成型工艺（LCM）下织物预成型体中双尺度流动以及由此造成的空气裹入,进而产生细观及微观气泡的现象。基于多相流（VOF）方法建立了树脂空气两相流体在单胞内部流动的数学模型,并确定了该模型中多孔介质阻力源项和毛细力源项的具体形式。基于Fluent软件的UDF功能实现了上述两相流模型的数值求解,研究了平纹织物单胞中的两相流动以及2种气泡的生成过程。对Rovcloth 2454织物的气泡生成仿真结果显示,毛细数 Ca 对气泡的产生有决定性作用：当毛细数接近临界毛细数 Ca^c时,气泡产生量最低,而当Ca小于Ca^c时,容易产生细观气泡,反之容易产生微观气泡。通过与文献中的理论预测和实验数据对比,验证了本文算法的正确性。     

岩石膨化硝铵炸药研究

详文讨论了膨化到铵的膨化机理及其技术特征，给出了岩石膨化硝铵炸约的爆炸与物理我数据，并与其它主要工业炸药作了比较。由于该炸药具有突了的优点，膨化硝酸铵技术被很多工厂广泛应用。     

Two-phase bubbly flows in microgravity: Some open questions

Several studies on gas-liquid pipe flows in micro gravity have been performed. They were motivated by the technical problems arising in the design of the thermohydraulic loops for the space applications. Most of the studies were focused on the determination of the flow pattern, wall shear stress, heat transfer and phase fraction and provided many empirical correlations. Unfortunately some basic mechanism are not yet well understood in micro gravity. For example the transition from bubbly to slug flow is well predicted by a critical value of the void fraction depending on an Ohnesorge number, but the criteria of transition cannot take into account the pipe length and the bubble size at the pipe inlet. To improve this criteria, a physical model of bubble coalescence in turbulent flow is used to predict the bubble size evolution along the pipe in micro gravity, but it is still limited to bubble smaller than the pipe diameter and should be extended to larger bubbles to predict the transition to slug flow. Another example concerns the radial distribution of the bubbles in pipe flow, which control the wall heat and momentum transfers. This distribution is very sensitive to gravity. On earth it is mainly controlled by the action of the lift force due to the bubble drift velocity. In micro gravity in absence of bubble drift, the bubbles are dispersed by the turbulence of the liquid and the classical model fails in the prediction of the bubble distribution. The first results of experiments and numerical simulations on isolated bubbles in normal and micro gravity conditions are presented. They should allow in the future improving the modelling of the turbulent bubbly flow in micro gravity but also on earth.     

全自动粉状硝铵炸药生产技术的分析和设计

通过对硝酸铵敏化机理的研究,探求无梯硝铵炸药影响敏化的主要因素,以及无梯硝铵炸药选择硝铵改性进行敏化的可行路线,介绍了全自动粉状硝铵炸药自动化连续化工业生产的工艺过程。     

Breath Figures as a Dynamic Templating Method for Polymers and Nanomaterials

This review describes the use of breath figures as a templating method for the fabrication of self‐assembled polymeric‐ and nanoparticle‐based micro‐ and nanostructures. If moist air is blown over a solution of a polymer or stabilized nanoparticles in an organic solvent, such as carbon disulfide, benzene, or chloroform, evaporative cooling leads to the formation of water droplets on the liquid surface. The monodisperse droplets arrange into a hexagonal array and sink into the polymer solution. Removal of the solvent and the water leaves an imprint of the water droplets as a hollow, air‐filled, hexagonally ordered, polymeric bubble array. Progress in the field of breath‐figure formation is reviewed. The application of breath figures for the generation of functional structures in chemistry and materials science is discussed.     

Freezing of air-entrained cement-based materials and specific actions of air-entraining agents

The freeze–thaw resistance of all cement-based materials is improved by incorporating a fine air bubble system in them. For acceptable life expectancy, incorporated air bubble volume should be about 25% of the cement paste. The specific surface of the air bubble system need to be above 25 mm²/mm³ and a spacing factor below about 0.16 mm. Powers explained these on the basis of his saturated flow hydraulic pressure mechanism. According to Powers’ mechanism, the chemical nature of the air-entraining agent has no part in this improvement in performance.Helmuth, one of the principal co-workers of Powers, has questioned a number of assumptions of Powers’ mechanism. Most importantly, Helmuth showed that ice penetrates concrete as dendritic crystals. Furthermore, a number of workers have shown that the chemical nature of the air-entraining agent affects the freeze–thaw resistance of cement-based materials. Some air-entraining agents do not improve the freeze–thaw resistance even though they entrain air of the required characteristics.In this paper, a modified and expanded version of Helmuth’s model of ice penetration in concrete is utilised to explain the action of air bubbles. All air bubbles contain a layer of water on their inner surfaces. Surface tension spreads out water in the air bubbles as annular layers. Air-entraining agents may form or precipitate hydrophobic layers on air bubble surfaces. When an ice dendrite reaches an air bubble, the annular water layer freezes to an annular layer of ice. The hydrophobic layer on the air bubble surface reduces the ice–paste bond. Under this circumstance, the ice layer within the air bubble grows. During this growth, water is withdrawn from the surrounding by suction. A water movement under suction does not produce any expansive pressure. Withdrawal of water to the air bubbles explains the beneficial action of air entrainment. The specific efficiency of air-entraining agents is explained by the different degree of hydrophobicity produced by air-entraining agents.