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61.
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Interaction of impact shock waves that could detonate an explosive (Composition B) confined in a thin-walled container impacted by a cone-nosed projectile is numerically studied, based on the Forest Fire explosive reaction rate model. The normal impact on the container by a small projectile with a conical nose is considered. Depending on the cone angle of the nose part of the projectile, the zone of interaction of initiating shock waves can be remote from the central axis of the impact. The off-the-central-axis detonation is interpreted from the viewpoint of different interaction modes in the explosive container, which are reflected from the cassette wall, change their directions, and superimpose onto each other, leading to explosive detonation. 相似文献
63.
Mechanical properties of high-strength concrete after fire 总被引:2,自引:0,他引:2
With compressive strength grade of C40, C60, and C70, respectively, normal-strength concrete (NSC) and high-strength concrete (HSC) were used to investigate compressive strength, splitting tensile strength, and bending strength after high temperature. The oil furnace is used in this study. Its temperature-time curve is close to standard curve, which conforms to Chinese standard GB/T 9978-1999. After being heated to temperatures of 200, 400, 600, 800, and 1000 °C, respectively, the mechanical properties of HSC were tested. The influence of temperature, water content, specimen size, strength grade, and temperature profiles on mechanical properties of HSC are discussed. 相似文献
64.
65.
Protective coatings from diethylphosphatoethyltriethoxysilane (DEPETS) have been deposited on different polymer substrates in a plasma discharge operated at atmospheric pressure. Plasma polymer chemistry and structure were characterized by means of Fourier transform infrared spectroscopy (FTIR), laser desorption ionization-mass spectrometry (LDI-MS), nuclear magnetic resonance (NMR) and scanning electron microscopy (SEM). A chemical structure of the plasma polymer has been proposed based on the coating molecular characterization. Coatings were deposited on polycarbonate (PC) and polyamide 6 (PA6) substrates. The flame retardant properties of coated substrate samples were assessed using cone calorimetry and compared to those of bare substrates. A significant increase in the time to ignition (TTI), up to +143%, was recorded after coating deposition due to the formation of a high-performance barrier layer at the surface of both polymer substrates. 相似文献
66.
氟碳表面活性剂因其高表面活性、高耐热稳定性、高化学稳定性以及带有氟元素的烃基同时具有憎水性和憎油性的特点在消防灭火领域广泛应用。对表面活性剂的结构、分类、特性、合成方法、在消防领域应用方面进行了系统阐述,最后进行了展望,以期对未来氟碳表面活性剂的研究有所帮助。 相似文献
67.
Superfine spherical hollow ammonium dihydrogen phosphate fire-extinguishing particles are prepared by spray drying and modified in situ with silicon oil emulsion. The results show that the amount of rough particles increased observably when the proportion of silicon oil emulsion is increased from 9 to 15 wt%, while no significant difference is detected when the proportion of silicon oil emulsion was varied from 0 to 9 wt%. The flowability of particles is improved with an increase in the proportion of silicon oil emulsion; 9.0 wt% is the optimal proportion of silicon oil emulsion for improving the hydrophobic performance of particles. Fire-extinguishing tests show that the fire-extinguishing capability of spray-dried superfine spherical hollow ammonium dihydrogen phosphate fire-extinguishing particles is much better than the two varieties of existing superfine dry chemical fire-extinguishing agents. 相似文献
68.
Multiple explosions occurred when five workers were acting on a footbridge structure at the top of crude olive pomace oil tanks. Welding on the tank roofs was performed without previously cleaning the tanks stopping their operation. First, one of the several ~ 650‐m3 reservoirs exploded, provoking a pool fire that spread throughout the tank farm. Roughly 1 h later, two other reservoirs exploded causing the launching of missiles to a distance of 60–80 m and a huge fire that extended throughout the entire tank farm. Four workers were killed instantaneously. The explosion was caused by the unusually high content of hexane in the crude olive pomace oil and, hence, by the inefficiency of the desolventization process which creates a flammable and explosive oil from a combustible one. 相似文献
69.
介绍了三氯氢硅的理化性质及生产原理,从电解、合成、贮罐等方面分析了三氯氢硅生产的火灾危险性,指出了防火防爆对策及泄漏处理和火灾扑救方法。 相似文献
70.