Mechanism of smoke suppression by melamine in rigid polyurethane foam

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.     

橙浊的生产及应用

阐述了橙浊珠生产及影响橙浊稳定性的主要因素，探讨了橙浊在饮料生产中的应用。     

The relationship between photo-catalytic performance and optical property over Si-incorporated TiO2

This study focuses on the relationship between photo-catalytic performance and optical property over Si-incorporated TiO₂. The Si-incorporated TiO₂ particles exhibited a pure structure of anatase having a particle size of less than 20 nm and surface area of more than 190 m²/g. The absorbance did not shift to a higher wavelength in spite of the incorporation of the Si ions, but the intensity of the photoluminescence (PL) curve was the smallest in the case of the 2.0 mol% Si-TiO₂, which was related to the recombination between the excited electrons and holes. Based on these results, the photodecomposition of methyl orange in the liquid reaction was enhanced over the 2.0 mol% Si-incorporated TiO₂ compared with that over pure TiO₂: Methyl orange at 10.0 ppm was completely decomposed after 100 min when 1.0 g of the 2.0 mol% Si-incorporated TiO₂ was used.     

Indoor Air Quality: Exploring Policy Options to Reduce Human Exposures

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.     

暖通空调工程设计常见问题

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。     

Photocatalytic degradation of methyl orange using heteropolytungstic acid-encapsulated TiSBA-15

Heteropolyphosphotungstic acid (H₃PW₁₂O₄₀) (HPA)-encapsulated titanium-supported SBA15 nanoporous materials (HPA-TiSBA-15) were synthesized as a new photocatalyst, and they were characterized by FT-IR and ³¹P NMR MAS spectroscopic methods. Their photocatalytic effects on degradation of methyl orange in water were investigated under natural conditions, and it was found that a 4-fold increase in the photodegradation rate is observed in the presence of HPA-TiSBA-15 as compared to the rate observed in the presence of titanium-supported SBA15 nanoporous materials (TiSBA-15) without HPA.     

55t/h锅炉技术改造成功经验

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。     

钼酸盐阻燃抑烟剂研发现状

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     

Photocatalytic properties of screen-printed titania

Nanocrystalline thin films of important surface roughness and complexity were prepared by screen-printing of commercial TiO₂ powder. The screen-printed titania films were tested in the photocatalytic decomposition reaction of methyl orange under UV light (350 nm). The photocatalytic activity strongly depends on the titania paste components and especially on the presence of a surface modifier (acetyl acetone) combined with a rheology controlling agent (ethyl cellulose). This results in improvement of the paste viscosity and optimization of the films morphology. Experiments under direct full sunlight illumination prove the importance of the screen-printed films for practical applications.     

抗红外成像制导技术浅析

红外成像制导导弹自诞生以来 ,经过数十年的发展 ,技术日臻完善 ,应用日趋广泛 ,研究和探讨对抗红外成像制导的技术和方法就显得尤为重要。介绍了红外成像制导的基本原理、发展和在战争中的重要作用 ,重点探讨了对抗红外成像制导的几种技术手段。