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排序方式: 共有3241条查询结果,搜索用时 15 毫秒
1.
The smoke suppression of rigid polyurethane foam (RPUF) modified by melamine was investigated based on three sections: the condensed phase, the carbon layer, and the gas phase. In the condensed phase, the results of thermogravimetry, X‐ray photoelectron spectroscopy (XPS) N1S spectrum, and Fourier transform infrared spectroscopy indicated that melamine could suppress the degradation of RPUF by reacting with the aromatic hydrocarbons. It also reduced the smoke generation because the volatilizable aromatic hydrocarbons were the principal smoke precursors in a fire. In the carbon layer, the decrease from 38.50% to 24.76% of the inner layer oxygen content identified by XPS full‐spectrum and C1S spectrum indicated that melamine could prevent oxygen from transferring into the inner foam by the formation of an enhanced surface carbon layer, and the enhanced carbon layer could also block the release of smoke precursors. In the gas phase, the content of total aromatic hydrocarbons declined to 59.12% according to pyrolysis gaseous chromatography mass spectroscopy and indicated that melamine could reduce the smoke precursors. The results of smoke density chamber and cone calorimeter tests revealed that the addition of the melamine could decrease the smoke density of burning RPUF. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
2.
Kevin Yale Teichman 《Indoor air》1994,4(3):202-211
Deciding between the different policy approaches available for reducing human exposures to indoor pollutants is an exceptionally complex task. These options can range from waiting until more definitive information is available to enacting regulatory standards, with many variations in between. This paper presents some of the factors policy-makers must consider in establishing indoor air quality policies, and the role researchers should play in ensuring that indoor air policies are based on the best available scientific information. 相似文献
3.
暖通空调工程设计常见问题 总被引:1,自引:0,他引:1
通过对施工图审查工作进行总结,指出了暖通空调和防火防排烟设计中存在的问题及防火规范本身的一些不足。 相似文献
4.
介绍了35t/h锅炉扩容改造为55t/h非标锅炉的技术成功经验。从增加锅炉的容积、受热面面积、燃烧器喷嘴改造三个方面介绍了对锅炉本体的改造,改造后实现了锅炉的水位、汽温及燃烧自动调节,提高了锅炉的热效率为以后的锅炉扩容改造提供了实践经验。 相似文献
5.
钼酸盐阻燃抑烟剂研发现状 总被引:2,自引:1,他引:1
简要地叙述了钼酸盐类阻燃抑烟剂 ,如八钼酸铵、钼酸锌、钼酸钙、钼酸钴和三氧化钼等阻燃抑烟剂的研发现状 相似文献
6.
A series of long-chain quaternary ammonium halogen esters (UKK-chemicals), quaternary dimethyl tallow epoxypropyl ammonium
halogens (EPK1), quaternary ditallow methyl epoxypropyl ammonium halogens (EPK2), and EPK2 oligomers (EPK2P) were synthesized.
At acidic, neutral, or slightly basic conditions, EPK1-, EPK2-, EPK2P-, and UKK-chemicals operate as cationic chemicals. They
can be used, for example, as stock sizings, surface sizings, or fixatives. Stock sizing, surface sizing, and fixative experiments
indicate that EPK1-, EPK2-, EPK2P-, and UKK-chemicals function at least as well as or better than the corresponding synthetic
chemicals used in papermaking. 相似文献
7.
8.
Simultaneous polymerization and doping of pyrrole have been carried out in the presence of a halogenic electron acceptor, bromine (Br2) or iodine (I2), in aqueous dispersion or in a two-phase solvent system. The morphology of the polypyrrole (PPY) so produced is granular and porous. The electrical conductivity of the PPY-I2 charge transfer (CT) complex is of the order of 101 ohm−1 cm−1 while that of the PPY-Br2 complex is about one order of magnitude less. Both complexes are stable in the atmosphere. The physicochemical properties of the PPY-I2 and PPY-Br2 CT complexes prepared under various experimental conditions are examined in detail. 相似文献
9.
DCS在采暖锅炉房中的应用 总被引:2,自引:1,他引:1
介绍了Jx—300X DCS系统的组成、功能、特点以及热水锅炉主要控制方案及其在锅炉测控方面的应用。 相似文献
10.
采用极限氧指数法、热重分析和烟密度测试法研究了氯氧镁水泥在不饱和树脂(UP)中的阻燃作用和阻燃机理。研究表明经偶联剂处理后的氯氧镁水泥对UP具有良好的阻燃抑烟效果,并通过增加UP在高温下的热稳定性和降低热失重速率等机理发挥阻燃作用:氯氧镁水泥含量在40%内对UP的力学性能影响较小,是一种新型的无机添加型阻燃剂。 相似文献