New fire‐protective intumescent coatings for wood

Polyurethane coatings are highly flammable, and because of their widespread applications on different substrates (wood, steel, and building materials), there is a need to increase their fire‐safety properties. Intumescent additives sharply suppress the flammability properties of polyurethane coatings. Two problems accompany intumescent additives: their high loading percentage and incompatibility with polyurethane coatings. In this research, we succeeded in increasing the compatibility by mixing intumescent additives with a butyl acrylate polymer and in lowering the flame‐retardant additive loading (up to 20%) by incorporating newly modified montmorillonite. The flammability properties of the new intumescent coatings were characterized with a cone calorimeter. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

氯氧镁水泥对不饱和树脂的阻燃性能与阻燃机理研究

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。     

导数火焰原子吸收法对调味品中锌的测定

将微量脉冲进样技术和导数火焰原子吸收法结合，建立了测定调味品中锌含量的新方法。该方法的检出限为0．013μg／mL，精密度4．46％，回收率96．67～113．33。     

有机纤维材料用软膜乳液阻燃剂的制备

采用甲醛、尿素、三聚氰胺、脒基脲磷酸盐为原料,以硼砂、硼酸、氨水为pH调节剂合成了保护胶;在保护胶存在下,以预乳化的丙烯酸酯混合单体于82-88℃共聚合成乳液,将其涂布于有机纤维材料,干燥后得软膜透明阻燃涂层。用其处理的涤棉布阻燃性能为:损毁长度68mm、续燃时间1s、阴燃时间3s、氧指数62、吸附干量287g/kg,处理的纸板的阻燃性能为:平均炭化长度77mm、平均续焰时间2s、平均续灼燃时间32s、吸附干量283g/kg。     

Experimental and numerical analyses of magnetic effect on OH radical distribution in a hydrogen-oxygen diffusion flame

The effect of magnetic field on OH radical distribution in a hydrogen-oxygen diffusion flame was experimentally and numerically investigated to explore the possibility of combustion control by magnetic force. In experiments, a coaxial type of burner was set between the magnet pieces. Two-dimensional (2D) cross-section distributions of OH* chemiluminescence intensity and OH fluorescence intensity were obtained with spectroscopic techniques using a CCD camera and a Planar Laser-Induced Fluorescence (PLIF) system, respectively. It was clearly seen that the high-density regions of OH* and OH radicals axisymmetrically migrated toward the central axis of the flame due to the influence of the magnetic field. In numerical simulations, such a phenomenon was qualitatively reproduced by solving the equations of reactive gas dynamics and magnetism. As a result, it was found that the magnetic force does not directly and selectively induce the diffusion velocity (the relative velocity) of OH itself. Alternatively, the magnetic force acting on O₂, whose mass density and magnetic susceptibility are much larger than those of other chemical species, causes the change in the mean velocity (the mass-average velocity) of mixture gas to transport the OH radical distribution indirectly and passively.     

基于物理模型的三维火焰实时渲染

火焰等无规则物体的模拟近年来成为计算机图形学中的一个研究热点。传统的基于粒子和纹理技术生成的火焰,并不能真实地反映物体的运动过程,生成的火焰效果图具有随机和生硬的特点。为了解决火焰模拟过程中难以实现的实时性和真实感的问题,文中采用一种基于物理模型的火焰实时渲染方法,应用有限差分法求解Navier-Stokes方程,采用半拉格朗日法求解平流项,扩散方程则利用隐式迭代方法进行求解,利用GPU强大的并行计算能力对求解过程进行加速,利用光线投射算法对火焰进行渲染,最后生成了逼真的火焰图像。实验结果表明该方法实现简单,渲染速度快,显示的效果真实。     

火焰动画快速模拟的新方法

针对火焰动画难以快速建模和绘制的问题,提出了完全利用GPU过程化生成火焰动画的高效算法。先用建模工具在预处理阶段构建一个由平面正方形组成的三维模型,在绘制阶段通过GPU编程对这些方形进行Billboard方式的变换,并用一些简单公式对他们的运动方式、大小和颜色来用过程化方式进行控制,最后通过alpha混合得到最终结果。算法完全在GPU里实现,能满足实时的绘制要求。     

基于北斗卫星的森林火灾监控终端设计

针对传统森林火灾监控方式存在的受地形限制,导致火灾发现不及时和定位难的缺陷,设计了基于北斗卫星的森林火灾监控系统,实现了火灾智能识别和预警,并且可以对火源、火场进行快速定位和信息通报;终端包括烟采集处理模块、图像采集模块、DSP处理模块、ARM主控模块和北斗卫星通信模块五部分,从烟和火焰两个方面对森林实时进行监控,分别采用离子烟雾传感器和DSP火焰识别混合算法,提取火焰图像差值和火焰图像边界参数的方法,提高了识别的准确率;试验证明,系统具有结构简单、使用方便和识别智能化的特点。     

阻燃型氢氧化镁制备及其影响因素探讨

以七水硫酸镁为原料、氨水为沉淀剂、选择适宜的表面活性剂。以样品XRD图中（001）面与（101）面衍射峰的相对强弱为考察指标，通过单因素实验，分别考察了反应温度、恒温反应时间、陈化时间、表面活性剂用量及氨镁摩尔比等因素对氢氧化镁样品XRD图中（001）面与（101）面衍射峰相对强弱的影响。实验结果表明，制备阻燃氩氧化镁较适宜的工艺条件为：反应温度40℃、恒温反应时间40min、陈化时间120min、表面活性剂A体积用量4ml、氨镁摩尔比6：1.     

Synergistic effects of organically modified montmorillonite in combination with metal oxides on the fire safety enhancement of intumescent flame-retarded epoxy resins

Synergistic effects of organically modified montmorillonite (OMMT) in combination with different metal oxides (Bi₂O₃, Sb₂O₃, and MoO₃) on the fire safety enhancement of the intumescent flame-retarded epoxy resins (EPs) were systematically evaluated. The results from X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses show that the OMMT and metal oxides acquire a uniform distribution in the EP matrix, and OMMT platelets exhibit a fully exfoliated state. The flammability and thermogravimetry (TG) tests show that the intumescent flame retardant (IFR)-OMMT-metal oxide ternary system can endow EPs with the higher synergistic efficiencies on the enhancement of flame retardancy, smoke suppression properties, and charring ability compared to those of IFR or IFR-OMMT system, and the synergistic efficiency is the following order: IFR/OMMT/Sb₂O₃ > IFR/OMMT/MoO₃ > IFR/OMMT/Bi₂O₃. In particular, the sample, filled with 1.5 wt% OMMT, 1.5 wt% Sb₂O₃, and 27 wt% IFR, passes the UL94 V-0 rating and acquires the highest limiting oxygen index value of 28.5% among the samples. The IFR-OMMT-metal oxide ternary system exerts a better synergistic effect on the generation of crosslinking and aromatic structures that supply the excellent charring effect and barrier effect for the EPs, and the synergistic efficiency of IFR-OMMT-metal oxide ternary system is varied with the types of metal oxides.