Seg—C型固态乳化复合粒状炸药的研制

文章阐述了Ｓｅｇ－Ｃ型固态乳化复合粒状炸药的配方与制备技术特点，给出了炸药性能、试验方法和井下小孔径炮孔爆破试验的结果。     

西德的胶质炸药与粉状炸药生产工艺

本文简要介绍西德工厂生产胶质炸药和粉状炸药所采用的现代工艺技术,其内容包括原料猛炸药的制备、生产工艺过程、设备类型、自控方式、技术安全设施等。     

含过期火药粉状工业炸药的研究

文章概要论述了一种新型民用炸药－含过期火药粉状工业炸药在配方、制造工艺等方面所进行的实验研究。结果表明，该炸药性能良好、制造技术安全可靠，值得推广。     

关于改变2号岩石硝铵炸药配方的初探

硝铵炸药大都是以硝酸铵、木粉、TNT为主要成分的混合炸药。近年来由于各种原材料的不断上涨,已给硝铵炸药生产带来了危机感,这也迫使生产厂家和科研单位不得不探索降低成本、提高效益的新路。笔者通过查阅有关资料,初步探讨了在炸药设计中改变2~＃岩石硝铵炸药配方,仅供参考。一、改变2~＃岩石硝铵炸药配方的设想煤炭是价格十分便宜的一种燃料,但也是作功的一种能源。煤在空气中燃烧时生成CO_2气体并放出大量的热。但由于其燃烧速度缓慢,故不能成为一种爆炸物质。据有关资料报道,1kg煤在燃烧时能产生的热量相当于1kg常用炸药的两倍以上,借助上述煤     

军工炸药边角余料利用的试验研究

军工生产弹类时产生的边角余料和废炸药,过去国内外作销毁处理,造成环境污染和经济损失。文中介绍了军工生产的边角余料TNT/RDX、TNT/Ba(NO_3)_2铸件炸药与NH_4NO_3配制各种民用混合炸药,TNT/RDX的再成型,TNT/Ba(NO_3)_2的分离以及废TNT提纯(分离或提纯后达到民用标准)的试验研究及生产应用。     

刚性被筒炸药的研究

刚性被筒炸药是一种以多种消焰剂为主要成分,由胶结剂粘合而成的刚性被筒,筒内装有2~#、3~#煤矿铵梯或孔化炸药等而成的一种抗井下瓦斯的高安全炸药。通过优选的刚性被筒壳可使该种炸药安全度显著提高,悬吊试验可通过300g。该种炸药的研究成功,为发展煤矿许用型炸药开辟了一条途径。     

瑞典BOFORS公司民用炸药主要测试方法简介

一、静电火花感度用于确定粉、粒状炸药对静电火花的感度。 1.实验装置主要有一个带圆形空穴(深2mm,直径12mm)的装样品容器,高压电流,充电电路,低损耗电子开关,电极组和静电电压计等。其中高压电源能以0～25KV的高压给电容器充电,充电电路由电容器和系列电阻     

如何控制煤矿硝铵炸药生产中食盐含量的升高

我厂在生产3~＃煤矿硝铵炸药的历史上,曾因检测终点控制不佳,造成食盐检测结果比投入量高。一般比淮北煤研所分析结果偏高2～3％;86年下半年得到纠正后,1988年又因食盐偏高超标而返工处理三批,1988年5月底以前又有两次食盐偏高返工处理。由于食盐偏高而影制硝酸铵含量偏低,往往造成食盐、硝酸铵两项指标不合格。从因食盐偏高超标返工处理的五个批来看,问题都发生在大扫除以后,重新投料生产的第一、二天以内。如附表所示。因此,可见这是客观环境的影响。在大扫除用水冲     

高聚物在混合炸药中的应用

综述了各类天然高聚物、热塑性聚合物、含氟聚合物、有机硅聚合物、橡胶弹性体、热固性树脂、环氧树脂及活性高聚物应用于混合炸药中所应满足的条件;对一些高聚物的合成、结构、性能以及在混合炸药中的作用、用途进行了讨论。     

粉状乳化炸药的研究

文中介绍的粉状乳化炸药，具有乳化体系的微观结构，克服了胶体乳化炸药的一系列缺点，具有乳化炸药的爆炸性能，抗水、贮存性能好，工艺简单，是发展乳化炸药的一种新技术途径。     

Effect of manufacturing process on the mechanisms and mechanical properties of fly ash-based geopolymer in ambient curing temperature

The manufacturing process of geopolymer cement generally uses alkaline solutions mixed with alumina-silicate prime materials to form a cement paste. Other factors may be set up for the designated experiment, e.g., material constituents, activator’s concentration and curing regimes. One of the latent factors influencing the properties of geopolymer, which has received less attention, is a mixing method. General mixing and separate mixing processes, which have been previously studied, were synthesized as controlled procedures and compared with another alternative new mixing method called the pre-dry mixing process. The results have shown that the pre-dry mixing process provided high potential heat liberation, which could prove beneficial for curing purposes. It is confirmed that the proper mixing order leads to better results, especially for any of the alkaline-activated cementitious binders. With more practicality in field application, by just adding water, this process could be developed and applied in ambient temperatures.     

Evolution of dispersion of carbon nanotubes in Polyamide 11 matrix composites as determined by DC conductivity

Double-walled Carbon NanoTubes (DWCNTs) have been dispersed in a Polyamide 11 (PA11) matrix by two routes: in the solvent way, Polyamide 11 was first dissolved in its solvent to ensure a liquid state dispersion of carbon nanotubes by ultrasonic way; in the melt mixing way, an optimization of the extrusion parameters, such as mixing time, mixing speed, mixing temperature and screw rotation direction allow to reach satisfactory dispersion. Dispersion and percolation threshold have been compared thanks to the evolution of DC conductivity with carbon nanotubes weight fraction in Polyamide 11.     

DEM simulation for optimal design of powder mixing in a ribbon mixer

A ribbon mixer is often employed in powder mixing in a wide range of engineering fields. The structure of the ribbon mixer is extremely complicated. This structure makes it difficult to understand the mixing mechanism by experimental approaches due to problems related to accurate sampling. At present, the mixing mechanism in the ribbon mixer is empirically identified as convection, despite a lack of precise assessment. Additionally, experimental investigations to find the optimal design of the ribbon mixer have not been sufficiently conducted because of its prohibitive cost. As such, there is a lack of sufficient discussion concerning the design for better mixing in the ribbon mixer. Numerical technologies represent a promising approach for solving the aforementioned problems. Significant improvements in computer hardware have enabled numerical models such as the discrete element method (DEM) to be positively employed in powder mixing. In the current study, an identification approach is developed for convective mixing, and besides, the study explores an effective parameter for better mixing in the ribbon mixer using the DEM. A swept volume measurement approach due to paddle movement is newly developed to identify the main mixing mechanism as convection. Sensitivity analyses are performed to find an effective parameter for better mixing. Through the sensitive analyses, the blade width is indicated as an important factor for achieving better mixing. Moreover, this study shows that the relationship between the swept volume and mixing index remains, even if the paddle width changes. Thus, the swept volume measurement method is revealed as useful for identifying the mechanism as convection in the ribbon mixer. Thus, not only novel finding regarding the blade width for better mixing but also the development of an approach for identifying convective mixing in the ribbon mixer is presented herein. Incidentally, convection being the dominant mechanism is consistent with the novel finding regarding blade width achieving better mixing.     

混合模激光的模式拟合

通过研究混合模激光的模式分布,提出模阶数之和（２ｐ＋ｌ＋１）相同的模在混合模中占相同比例的假设,用计算机模拟的方法实现了混合模的模拟,理论模拟结果与实验测量的混合模分布很好地吻合,由此方法可模拟估算出混合模中各高阶模的强度比例。     

橡胶连续混炼粉料混合均匀性仿真及实验研究

为了提高橡胶连续混炼中混炼胶质量稳定性,实现炭黑等粉体物料精确配比和均匀性混合问题,针对粉体物料在混合和输送过程存在复杂的物理性质,建立了炭黑等混合粉料的球体颗粒模型和Hertz接触力-位移模型,采用EDEM对典型粉体物料混合均匀性进行模拟仿真和粉体物料混合实验,对炭黑等粉体物料在橡胶连续混炼工艺中的混合均匀性进行分析,探求橡胶粉料连续混合和输送机理.研究发现:粉体物料混合仿真与实验测试结果具有较高的拟合性,表明在橡胶连续混炼工艺中可以在保证混合均匀性的前提下实现多粉体混合物的连续称量和输送,同时也验证了运用EDEM数据模拟仿真粉体物料混合的可行性.     

The mixing effects for real gases and their mixtures

The definitions of the adiabatic and isothermal mixing effects in the mixing processes of real gases were presented in this paper. Eight substances with boiling-point temperatures from cryogenic temperature to the ambient temperature were selected from the interest of low temperature refrigeration to study their binary and multicomponent mixing effects. Detailed analyses were made on the parameters of the mixing process to know their influences on mixing effects. Those parameters include the temperatures, pressures, and mole fraction ratios of pure substances before mixing. The results show that the maximum temperature variation occurs at the saturation state of each component in the mixing process. Those components with higher boiling-point temperatures have higher isothermal mixing effects. The maximum temperature variation which is defined as the adiabatic mixing effect can even reach up to 50 K, and the isothermal mixing effect can reach about 20 kJ/mol. The possible applications of the mixing cooling effect in both open cycle and closed cycle refrigeration systems were also discussed.     

On the magnitude and variability of the fatigue strength of acrylic bone cement

When used for the fixation of orthopaedic implants poly(methyl methacrylate) bone cement is prepared during surgery, and polymerises in situ. The technique for preparation of the bone cement involves mixing the liquid monomer and powder: two common mixing methods are hand mixing and vacuum mixing. Previous studies have shown that porosity depends on mixing technique. In this study, the fatigue strength of hand-mixed and vacuum-mixed cements is measured and correlated with the pore distribution resulting from each mixing technique. S–N curves show that vacuum mixing improves the fatigue strength by an order of magnitude. However, there is greater variability of fatigue strength associated with vacuum-mixed cement. This is correlated with the appearance of an occasional large pore in the vacuum-mixed cement. If the cross-sectional area is corrected to take account of porosity in vacuum-mixed cement, an 8% increase in the association of the data is found. Using a two-parameter Weibull model, it can be shown that the vacuum-mixed cement has a greater Weibull life at the 50% probability-of-survival level. However, if a probability-of-survival close to 100% is required (i.e. high reliability), the hand-mixed cement is found to have superior fatigue behaviour. The S–N curves can be explained by examination of the fracture surface features. The initiation stage of fatigue cracking is notably different for the two different mixing techniques. The lower fatigue strength of the hand-mixed cement can be explained by the interactions of pores on the fracture surface causing stress concentrations, whereas no such pore interactions occur in the vacuum-mixed cement.     

Experimental and modeling studies on mixing behavior of binary mixtures in a spout-fluid bed

Experimental and modeling studies have been performed to determine mixing characteristics of binary mixtures in a spout-fluid bed. Spherical glass beads of diameters (3.075, 1.7, 1.2, and 0.75?mm) and air as fluidizing medium have been used in the study. Effect of various system parameters, namely, initial static bed height, gas velocity, diameter ratio, mixture composition, and sampling time on mixing of binary particles has been experimentally investigated. A dimensionless correlation has been developed for mixing index. Mixing behavior has been modeled using artificial neural networks (ANNs). Training of ANN was performed using the Levenberg–Marquardt (LM) backpropagation algorithm to predict the mixing index. The predictions of the ANN were found to be in good agreement with the experimental results and predictions from developed correlations.     

Mechano-chemical aspects of the processing/property/structure interactions in a macro-defect-free cement

Relationships between mixing conditions, relaxation properties of the formed paste, and the morphology and flexural strength of hardened composites have been studied for a macro-defect-free cement (MDF). Torque and temperature were monitored in a Banbury-type mixer as a function of temperature and mixing rate. The behavior of the torque-time curves as well as activation energies derived from the temperature dependence of the mixing time suggest that a mechano-chemical crosslinking takes place between the polymer and cement phases during mixing. The viscoelastic relaxation characteristics of MDF pastes processed to varying degrees were determined using a biaxial squeeze flow device. Relaxation times and their trends with mixing are consistent with the formation of an increasingly dense network structure in the paste. Flexural strengths of the hardened material display a behavior with mixing conditions which suggests that an optimal structure forms during that portion of the mixing process preceding breakdown of the paste. This conclusion is supported by the evidence of scanning electron micrographs which show the structure formation for a given set of mixing conditions.