Effect of RDX powders on detonation characteristics of emulsion explosives

ABSTRACT

To obtain an explosive suitable for the explosive welding of foils and produce a new way to reuse demilitarized explosives, RDX powders and high amounts of hollow glass microballoons (GMs) were introduced into an emulsion matrix to reduce detonation velocity and critical thickness. The effect of different percentages of RDX on the detonation performance of the mixtures was systematically investigated. The results showed that the critical thickness decreased significantly with increasing RDX contents, and the detonation velocity at the critical thickness was almost unchanged for the different RDX contents. Thus, the as-created mixtures were suitable for the explosive welding of foils due to their low detonation velocities and low critical thicknesses. The brisance test results indicated that the brisance of the composite explosives increased with increasing RDX contents, and this trend was more remarkable at low RDX contents. All the energy output parameters of the underwater explosions also increased with increasing RDX contents.     

Isothermal thermal decomposition of the HMX-based PBX explosive JOL-1

ABSTRACT

Isothermal thermal decomposition method was used to study the thermal behavior of the HMX-based PBX explosive JOL-1. The gas pressure versus time curves of the isothermal decomposition of JOL-1 were obtained within the temperature range of 90°C to 130°C. Kinetic parameters such as activation energy and frequency factor for the thermal decomposition of JOL-1 were obtained using the Arrhenius equation and model-fitting method. The model-fitting method further proved that the isothermal decomposition of JOL-1 at 90°C, 100°C, 110°C, 120°C, and 130°C is consistent with the No. 8 mechanism function, namely, the anti-Jander equation, controlled by 3D diffusion. The storage life of JOL-1 was estimated by the Semenov equation and the extent of reaction reached 0.1–0.4%. Results showed that the effective storage life of JOL-1 at 25°C, 40°C, and 60°C are 68 years, 10 years, 1 year, respectively, when the extent of reaction reached 0.1%.     

颗粒污染物对变压器油理化性能的影响

变压器油中存在颗粒污染物极易使油液劣化,影响设备的安全运行,从实验角度探讨了颗粒污染物对油液性能的影响规律。根据均匀设计法,配制了不同颗粒含量、不同污染度的含Cu、Fe颗粒油样和含Cu、Fe、SiO2颗粒的油样各24个,测试了油样的40℃运动黏度、击穿电压以及热氧化实验前后酸值,并比较了含和不含SiO2颗粒油样的这些理化性能变化的差别。结果表明,颗粒污染度对油液理化性能的影响较大。随着污染度的增加,含Cu、Fe、SiO2 3种颗粒油样的运动黏度呈下降趋势,其变化幅度为096 mm2/s;击穿电压呈下降趋势,其变化幅度为254 kV;油液热氧化后酸值升高,变化幅度为0073 mgKOH/g。含SiO2颗粒的油样的击穿电压和酸值的变化趋势与不含SiO2颗粒的油样的基本一致,含有SiO2颗粒的油样的击穿电压比不含SiO2颗粒的油样击穿电压要大,SiO2颗粒对油液热氧化前后酸值的影响不大。     

Effect of Pressure of the Casting Vessel on the Solidification Characteristics of a DNAN/RDX Melt-Cast Explosive

This study experimentally and numerically investigated the effect of pressure of the casting vessel on the solidification characteristics of a DNAN (2,4-dinitroanisole)/RDX(cyclotrimethylenetrinitramine) melt-cast explosive. The solidification and cooling time was recorded by a thermocouple, the distribution of the shrinkage porosity was observed and analyzed, and the density of the explosive charge was measured. The primary solidification characteristics were verified by numerical simulation achieved with ProCAST casting software, and results were in qualitative agreement with experimental results. Both the experimental and numerical results demonstrate that increasing pressure of the casting vessel can effectively diminish the shrinkage porosity, reduce the solidification time, and increase the relative density of the DNAN/RDX melt-cast explosive.     

Effect of Biological and Chemical Dispersants on Oil Spills

The aim of this work is to study the effect of different types of chemical and biological dispersants used for crude oil spill treatment. The dispersing efficiency of the different dispersants on the crude oil was determined for selecting the most effective one. The basic properties of crude oil participating in the efficiency of dispersion process as viscosity, pour point, wax content, asphaltene content, resin content, etc. were determined. Also the nature of the different dispersants on the dispersing process, studied by FT-IR analysis, showed the presence of the same effective functional groups but in different ratios. The hydrocarbons types distribution of crude oil undispersed and undispersed parts were used as a marker for the degree of dispersion and/or biodegradation. The lowest values of undispersed saturate indicate the highest degree of dispersion or biodegradation. The lower normal alkanes are much more dispersed than the higher ones. The enzyme showed a moderate efficiency for dispersing crude oil, and this efficiency increased by increasing the time of contact with oil which lead to the dispersion of higher molecular weight normal alkanes.     

Y分子筛化学脱铝对长链正构烷烃加氢异构的影响

研究了草酸脱铝对Ni/HY催化剂的结构及反应性能的影响。结果表明 ,随着脱铝量的增加 ,催化剂的比表面积和总酸量逐渐下降 ,硅铝比、介孔比例和Ni-Ni配位数增加。与未脱铝的Ni/HY催化剂相比 ,该催化剂在反应活性相同的条件下 ,对长链正构烷烃的加氢异构反应表现出较好的选择性。     

柴油碳烟对ZDDP摩擦反应膜的分布、成分及力学性能的影响

为研究柴油碳烟对ZDDP摩擦反应膜的分布、成分和力学性能的影响。采用HFRR摩擦磨损试验机进行了摩擦磨损试验。采用激光显微镜、SEM/EDS、拉曼光谱、XPS和纳米压痕仪对由ZDDP和碳烟摩擦磨损后的表面进行了分析。结果表明,碳烟会刮离ZDDP摩擦反应膜并嵌入磨损表面,导致膜厚减小和摩膜的不均匀分布。ZDDP摩擦膜中的磷酸盐结构由短链焦磷酸盐向长链偏磷酸盐转变,归于碳烟磨粒磨损引起的接触应力增加,促进了ZDDP的交联。磨损表面的硬度（H）和弹性模量（E）增加,而硬度与弹性模量的比值（H/E）降低,这表明碳烟导致耐磨性降低。     

Influence of Chemical Composition on the Physical Characteristics of Paving Asphalts

The simplest general compositional model considers asphalt to be made up of asphaltenes, heavy oils, and resins. In the present study the extent of similarity between the properties and composition of various types of asphalt obtained from different sources has been carefully explored. It shows how ductility, penetration, and softening point are related to the chemical nature of paving asphalts in the range 41-58 softening points. Asphalt properties are found to be a direct function of its chemical constituents. The relationship between softening point and asphaltene content was found to be linear while asphalts of the same softening point are easily distinguished by the content of the resins. Evaluation of the two asphalt indices—the asphaltene index (I_A) and the Gaestel index (I_C), reveals that they both vary linearly with the composition of asphaltenes and resins thus confirming their suitability in the characterization of asphalts. Comparison of the two indices shows that IC is more suitable in estimating the colloidal stability of different groups of asphalts. The observed correlations can be found useful in the areas of asphalt blending and rejuvenating through the appropriate selection of asphalt components.     

Influence of Chemical Composition on the Physical Characteristics of Paving Asphalts

Abstract

The simplest general compositional model considers asphalt to be made up of asphaltenes, heavy oils, and resins. In the present study the extent of similarity between the properties and composition of various types of asphalt obtained from different sources has been carefully explored. It shows how ductility, penetration, and softening point are related to the chemical nature of paving asphalts in the range 41–58 softening points. Asphalt properties are found to be a direct function of its chemical constituents. The relationship between softening point and asphaltene content was found to be linear while asphalts of the same softening point are easily distinguished by the content of the resins. Evaluation of the two asphalt indices—the asphaltene index (I _A ) and the Gaestel index (I _C ), reveals that they both vary linearly with the composition of asphaltenes and resins thus confirming their suitability in the characterization of asphalts. Comparison of the two indices shows that IC is more suitable in estimating the colloidal stability of different groups of asphalts. The observed correlations can be found useful in the areas of asphalt blending and rejuvenating through the appropriate selection of asphalt components.     

润滑油基础油组成结构与油泥沉积物之间的关系研究

借助低温油泥模拟试验机,考察了150～200粘度牌号的Ⅰ、Ⅱ、Ⅲ、Ⅳ类基础油的组成结构与油泥沉积物之间的关系,同时利用IR、MS、XPS等分析手段对基础油的烃类组成以及在低温油泥试验中产生的废油、油泥、漆膜的化学组成进行了分析,实验结果表明,该方法对传统基础油、加氢基础油和合成基础油的沉积物生成倾向有好的区分,基础油中的环烷烃、芳香烃和杂原子化合物是油泥、漆膜的主要来源。另外,还考察了基础油对分散剂的影响。     

乙烯氧氯化反应技术的研究Ⅰ．催化剂表面的物理结构及化学状态

借助现代检测设备，对目前工业上使用的乙烯氧氯化反应ＣｕＣｌ＿２／Ａｌ＿２Ｏ＿３催化剂表面的结构和化学状态进行测试分析结果表明，在正常反应条件下，活性组份ＣｕＣｌ＿２的流失并不严重，反应过程中反应气氛的不同主要是通过改变催化剂表面的Ｃｌ／Ｃｕ原子比来影响催化剂的化学活性；吸附在催化剂表面上的水，在２００℃以上的反应温度下已基本被脱除。同时，在反应过程中，催化剂表面活性组份Ｃｕ上进行的是氧化－还原反应，而且表面孔径会变大，比表面减小，机械强度也随之降低。     

道路石油沥青热稳定性能物化分析

通过对三种道路石油沥青老化前后试样进行元素分析、四组分分析、热重(TG)分析和红外光谱(FT-IR)分析,试验结果表明,沥青的热稳定性能主要体现在老化前后沥青中主要元素含量、组分组成及特征基团含量的变化,说明沥青的热稳定性能不仅与油源的资源属性密切相关,而且可通过干预沥青中主要元素的含量、化学组分的分布及特征基团的含量等生产出符合沥青宏观技术性能指标需求的合格产品.     

A New Family of Oil Spill Dispersants: Part 1. The Effect of Structural Variation on the Oil Spill Dispersant Efficiency

Abstract

New nonionic surfactants were synthesized through esterfication of a dicarboxylic acid (succinic or adipic acid) with fatty alcohols that have different molecular weight; namely, octyl, lauryl, and cetyl alcohol. The ester products were reacted with polyethylene glycols of different molecular weight (400, 600, and 1,000) to form compounds having different hydrophil-lipophil balances. The surface active properties of the prepared surfactants were evaluated, and the critical micelle concentrations were determined, so as to determine the Pc₂₀, effectiveness π_cmc, and maximum dispersion efficiency from the screening study.     

滑动弧光等离子体技术在化工中应用研究进展

滑动弧光等离子体综合了热平衡等离子体和非平衡等离子体的优点,是一种很有前景的等离子体技术。本文介绍了滑动弧光等离子体的产生过程及反应器结构,并对其在化工领域中的应用进行了综述。     

Experimental Investigation of Matricaria chamomilla Extract Effect on Oil-Water Interfacial Tension: Usable for Chemical Enhanced Oil Recovery

Recently, natural surfactants had been studied for chemical enhanced oil recovery as opposite to synthetic surfactants due to environmental problems associated with synthetic surfactants. In this study a new plant based natural surfactant, Matricaria chamomilla, is introduced. For this purpose, the interfacial tension values between natural surfactant solution and oil are measured by using the pendant drop method. The results show that Matricaria chamomilla decreased the oil-water interfacial tension values from 30.63 to 12.57 mN/m. Results confirm surface chemical activity of Matricaria chamomilla in comparison with other natural surfactants.     

地应力对爆炸压裂影响规律的数值模拟研究

为了揭示地应力场对井内爆炸压裂作用下裂缝形成及分布的影响规律,进行了井内爆炸压裂室内模拟试验。基于弹塑性损伤理论建立了井内爆炸压裂数值计算模型,在借助试验结果验证模型准确性的基础上,研究探讨了地应力场对爆炸压裂作用下裂缝扩展规律的影响。研究结果表明:试验条件下,炮眼内炸药爆炸后并未对炮眼造成粉碎性破坏,且裂缝沿曲线扩展;爆炸压裂作用下井壁围岩中将产生长而宽的主裂缝和短而细的次裂缝;主裂缝扩展方向受地应力场控制,垂直于最小水平地应力方向;不同地应力场条件下,裂缝扩展范围及密度亦随之发生改变。 研究表明,准确掌握地应力大小及方位,有利于控制主裂缝的扩展及分布形态。      

碱金属掺杂对NiFeAlO4载氧体结构及反应特性的影响

采用溶胶-凝胶法和浸渍法制备了碱金属掺杂的尖晶石结构NiFeAlO4载氧体,考察了制备方法、碱金属种类、碱金属掺杂比例对NiFeAlO4载氧体结构、煤化学链燃烧特性和循环稳定性的影响。结果表明,溶胶 凝胶法制备的钾掺杂NiFeAlO4载氧体具有更好的反应性,当载氧体与煤质量比为20∶1时,掺杂质量分数为5% K2CO3的NiFeAlO4载氧体与煤反应的碳转化率为99%,高于NiFeAlO4载氧体与煤反应时的碳转化率（87%）。与NiFeAlO4载氧体相比,掺杂质量分数为5% K2CO3的NiFeAlO4载氧体呈现出更好的循环稳定性,主要归因于碱金属K的掺杂改善了载氧体的反应活性,对载氧体的团聚有抑制作用,且反应前后载氧体晶相结构保持不变。     

渤海绥中36-1油田化学吞吐降粘技术初探

介绍化学吞吐工艺过程和作用原理,总结了A18井原油与化学吞吐剂的适应性评价过程,包括化学吞吐剂浓度的选择、不同油水比时的乳化降粘性能、乳化体系降粘率、油水界面张力的测量、润湿能力的定性考察和对原油破乳的影响等研究工作。在此基础上进行现场试验,对施工后的效果进行了分析,提出了存在的问题和建议。     

油田化学驱用部分水解聚丙烯酰胺环境基准值研究

为明确油田化学驱用聚合物是否会对矿区生态环境产生影响,依据国际构建环境基准所需最低毒性数据和实验选种准则,引入部分水解聚丙烯酰胺为环境本底引物,筛选出具有大港油田矿区特征的三门八科全覆盖的环境生物毒理受试物种,开展受试物种毒性实验,构建环境基准理论数值模型.结果表明,受试物种的环境生物急/慢性毒理值比为9.98,利用物...     

Effect of Chemical Nature on the Susceptibility of Asphalt to Aging

The knowledge of the factors affecting the susceptibility of asphalt to aging can be of help when selecting the asphalt binders for the construction of durable pavements. Investigated were the aging-induced changes in the chemical composition and colloidal nature of asphalts differing in origin and technology. It was shown that the course of the changes in the generic composition of asphalt upon aging under laboratory conditions depends on the chemical type of the feedstock from which the asphalt has been derived. During aging of the asphalts from the paraffin-naphthenic crudes, the resins undergo partial decomposition, which results in the increase of the cyclic fraction content. Although the increase of the asphaltene content in air-blown asphalts after the Thin Film Oven Test was found to be lower than that in the corresponding straight-run asphalts, the much higher value of the instability index and smaller size distribution of asphaltenes in the air-blown asphalts permit us to expect that their utilization as binders in pavement construction will lead to the reduction of pavement durability. It follows from the results of this study that not only the generic composition but also the structure of the fractions affect the resistance of asphalt to aging.