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41.
火灾烟雾的多波长衰减特性研究   总被引:2,自引:0,他引:2  
采用多波长激光同时与火灾烟雾与非火灾气溶胶相作用,研究了火灾烟雾对波长激光的衰减特性,得到了熏香烟雾和柴油明火烟雾等5种典型火灾烟雾和非火灾气溶胶的3对波长消光系数比的数值。结果表明,消光系数比反映了气溶胶粒子对两个波长激光衰减的相对程度,仅与气溶胶本质特征有关,不同烟雾气溶胶的消光系数比的数值有明显差别。  相似文献   
42.
Modelling of light extinction by soot particles   总被引:1,自引:0,他引:1  
A simplified model for the prediction of light extinction through combustion generated smoke is presented. The model builds upon existing theory and available experimental data to account for the principal factors that influence light extinction in participating media, including wavelength, primary particle size distribution and morphological structure of particle aggregation as well as multiple scattering among particles within a particle aggregation. Good agreement is demonstrated between the model predictions and experimental data in the visible and IR ranges. The model illustrates that as the mean particle size increases, the integral optical property of a soot cloud approaches that of monodisperse particles. It is postulated in the current study that the number of particles participating in multiple scattering is around 20 regardless of the real size of particle aggregation.  相似文献   
43.
Background and Aims: Smoke exposure of grapevines and development of smoke taint in wine are issues of increasing incidence and severity. There is limited understanding of the effect of phenological stage at the time of smoke exposure on taint development. The aim of this study was to demonstrate the variation in smoke uptake and taint development between and within seasons. Methods and Results: Smoke was applied to field‐grown Merlot grapevines at 12 stages of vine development over three growing seasons. Key periods of vine sensitivity to smoke taint in wine were (i) from shoots at 10 cm to full bloom (low levels of smoke taint); (ii) from berries at pea size to the onset of veraison (variable levels of smoke taint); and (iii) between 7 days post‐veraison and harvest (high levels of smoke taint). Conclusions: The severity of taint in wine varied depending on the phenological timing of grapevine smoke exposure. Taint was elevated when exposure occurred between 7 days post‐veraison and harvest. The carry‐over of smoke constituents the following season was not detectable in wine but yields were reduced. Significance of the Study: This is the first study to demonstrate the timing of smoke exposure to critically affect wine chemical and sensory characters. These effects were consistent and reproducible over three seasons.  相似文献   
44.
Background and Aims: Australian grape growers and winemakers have typically relied on guaiacol and 4‐methylguaiacol measurements to determine smoke exposure of grapes following bushfires or prescribed burns. However, the guaiacol and 4‐methylguaiacol content of grapes does not always correlate with the extent of taint in resultant wines. This study compared several methods for the analysis of smoke related phenols and their conjugates in grapes and wine, to determine their capacity as diagnostic assays for smoke exposure. Methods and Results: Smoke‐affected grapes were sourced from commercial vineyards exposed to bushfire smoke and from experimental field trials involving the application of smoke to grapevines, and small‐scale wines were made from a number of these samples. Several analytical methods were applied to grapes and wine to determine the concentration of smoke related phenols and their conjugates. Strong correlations were observed between the glycoconjugate content of smoke‐affected grapes and the concentration of guaiacol and 4‐methylguaiacol released following acid hydrolysis of juice. Conclusions: Where smoke‐affected grapes contain low or non‐detectable levels of guaiacol and 4‐methylguaiacol, analytical methods that quantify their glycoconjugate forms (either directly or indirectly) provide a better indication of the extent of smoke exposure. Significance of the Study: This is the first study to compare different methods for assessing smoke exposure in grapes and wine, through analysis of free and bound guaiacol and 4‐methylguaiacol. These methods will allow grape growers and winemakers to more reliably assess smoke exposure of grapes, enabling better informed decisions to be made with regards to harvesting and processing smoke‐affected grapes.  相似文献   
45.
光电成像末制导烟幕干扰效果评估研究   总被引:1,自引:0,他引:1  
建立了光电成像末制导烟幕干扰模型和干扰效果评估模型,利用仿真的方法研究了烟幕干扰对光电成像末制导武器关键制导参数和运动参数的影响,进行了光电成像末制导干扰效果评估研究。  相似文献   
46.
催化裂化烟机振动原因分析及应对措施   总被引:2,自引:2,他引:0  
通过对引起烟机振动值增加的因素进行分析,采取相应的措施,同时加强设备维护,减少工艺调整降低轴瓦振动,实现了机组长周期运行。  相似文献   
47.
多孔无机材料在卷烟减害降焦应用进展   总被引:1,自引:0,他引:1  
多孔材料添加剂因其具有大比表面积、高效吸附及表面化学可修饰性而越来越受到烟草科技工作者的青睐。总结了微孔活性炭、分子筛和介孔材料作为吸附剂和催化剂降低卷烟烟气中的有害成分,并提出了今后多孔材料在卷烟烟气减害降焦中的研究方向。  相似文献   
48.
卷烟主流烟气中主要酚类含量的分析研究   总被引:1,自引:0,他引:1  
采用高效液相色谱法对56种卷烟主流烟气中4种主要酚类化合物(对苯二酚、间苯二酚、邻苯二酚和苯酚)进行含量测定,结果表明,在卷烟主流烟气中:(1)对苯二酚、邻苯二酚和苯酚的含量随着卷烟档次的提高整体上均有升高的趋势,但苯酚含量波动较大;(2)间苯二酚的含量与卷烟档次无明显规律性,但是这4种酚类化合物总含量随着卷烟档次整体上有升高的趋势;(3)烤烟型卷烟中,对苯二酚、间苯二酚和邻苯二酚的含量整体上比在混合型中的高,但苯酚的含量整体上比在混合型中的略低;(4)国外混合型卷烟中,这4种酚类化合物的含量整体上均比在国内混合型卷烟中的高,而且苯酚高出了很多。  相似文献   
49.
介绍了高压电力电缆外护套材料的种类,从机械性能、电性能、阻燃性能等多方面分析了各种材料的优缺点,并希望用户在选型过程中,能够根据不同的使用环境采用性能最合适的非金属护套,以保证电缆在寿命期内安全运行。  相似文献   
50.
介绍了透射型太赫兹时域光谱系统实验装置和相关参数的提取方法,分别对绿色和黄色两种烟幕材料在太赫兹波段的光谱特性进行了实验研究,得到了这两种材料的折射率曲线和屏蔽效能曲线。实验表明,这两种材料对可见光和红外波段有较好的遮蔽特性,而对太赫兹辐射的屏蔽效能却较差,太赫兹侦察探测具有较强的抗干扰能力,能够弥补传统可见、红外探测系统的不足。  相似文献   
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