NH3 对二甲苯光氧化形成二次有机气溶胶的影响

二甲苯是一种重要的人为源 VOC, 也是城市地区 SOA 的重要前体物。二甲苯光氧化形成的 SOA 受多种环 境因素影响, 而 NH3 对该反应形成的 SOA 生成产率及反应机制的影响尚不清楚。基于室内烟雾箱模拟系统, 探讨了 NH3 对二甲苯光氧化形成 SOA 质量浓度、物理特性及化学组成的影响。研究表明, 在低浓度条件下, NH3 对二甲苯 光氧化生成 SOA 具有明显的促进作用, 结合气溶胶质谱结果发现 NH3 促进醛酮类物质进入颗粒相以及含氮有机物的 生成是导致 SOA 质量浓度增加的主要原因。此外, NH3 能够提高邻二甲苯生成 SOA 的吸光度, 但是对对二甲苯无明 显影响。分析表明, 相较于对二甲苯, 邻二甲苯光氧化会生成大量醛类物质, NH3 与醛类发生美拉德反应是导致 SOA 吸光性增加的主要原因。     

Comparing alternative cellulosic biomass biorefining systems: Centralized versus distributed processing systems

This study explores how two different cellulosic ethanol production system configurations (distributed versus centralized processing) affect some aspects of the economic and environmental performance of cellulosic ethanol, measured as minimum ethanol selling price (MESP) and various environmental impact categories. The eco-efficiency indicator, which simultaneously accounts for economic and environmental features, is also calculated. The centralized configuration offers better economic performance for small-scale biorefineries, while the distributed configuration is economically superior for large-scale biorefineries. The MESP of the centralized configuration declines with increased biorefinery size up to a point and then rises due to the cost of trucking biomass to the biorefinery. In contrast, the MESP in the distributed configuration continuously declines with increasing biorefinery size due to the lower costs of railroad transportation and the greater economies of scale achieved at much larger biorefinery sizes, including biorefineries that reach the size of an average oil refinery—about 30,000 tons per day of feedstock. The centralized system yields lower environmental impacts for most impact categories than does the distributed system regardless of the biorefinery size. Eco-efficiency analysis shows that the centralized configuration is more sustainable for small-scale biorefineries, while the distributed configuration with railroad transport is more sustainable for large-scale biorefineries. Compared with gasoline from petroleum, cellulosic ethanol fuel offers sustainability advantages for the following environmental impact categories: fossil energy consumption, global warming, human health impacts by particulate matter, ozone layer depletion, ecotoxicity, human health cancer, and human health non-cancer, depending somewhat on the biorefinery sizes and the system configurations.     

隧道火灾过程的动态数值模拟

为了解某特长隧道发生火灾后,隧道内烟雾及温度的分布情况,利用地下工程火灾原理建立了计算隧道内空气温度、壁面温度及火灾烟雾浓度的火灾模型,并编制了动态仿真程序.对隧道内不同位置发生火灾时,隧道内空气温度、壁面温及火灾烟雾浓度随时间、空间的分布情况进行了模拟计算,给出了隧道内不同位置发生火灾时不发生烟气回流的通风控制要求,并分析了火灾时高温烟气对风机损坏的情况.     

光化学烟雾及遥感技术在其监测中的应用

论述了光学烟雾的特征、形成条件、形成机理、危害、防治对策、以及遥感技术在大气污染监测中的应用。     

Image smog restoration using oblique gradient profile prior and energy minimization

Removing the smog from digital images is a challenging pre-processing tool in various imaging systems. Therefore, many smog removal (i.e., desmogging) models are proposed so far to remove the effect of smog from images. The desmogging models are based upon a physical model, it means it requires efficient estimation of transmission map and atmospheric veil from a single smoggy image. Therefore, many prior based restoration models are proposed in the literature to estimate the transmission map and an atmospheric veil. However, these models utilized computationally extensive minimization of an energy function. Also, the existing restoration models suffer from various issues such as distortion of texture, edges, and colors. Therefore, in this paper, a convolutional neural network (CNN) is used to estimate the physical attributes of smoggy images. Oblique gradient channel prior (OGCP) is utilized to restore the smoggy images. Initially, a dataset of smoggy and sunny images are obtained. Thereafter, we have trained CNN to estimate the smog gradient from smoggy images. Finally, based upon the computed smog gradient, OGCP is utilized to restore the still smoggy images. Performance analyses reveal that the proposed CNN-OGCP based desmogging model outperforms the existing desmogging models in terms of various performance metrics.     

食用油质量自动检测系统的设计与实现

介绍了一种基于单片机的食用油质量自动检测系统.烟点是食用油质量的标志,系统以AT89S51单片机为内核,利用油烟传感器和K型铠装热电耦分别检测油烟信号和温度信号,并采用4位数码管对烟点值进行锁存显示,从而实现对食用油质量的标定,具有测量精确度高、油烟浓度可调、成本低等优点,大大提高了检验效率.     

新型矿用便携式可组网烟气监测分析仪的研制

针对现有以电化学传感器为主的便携式烟气分析仪存在灵活性和普适性差,便携式光纤烟气分析仪无法实现数据远程传输和多传感器联合组网的问题,研制了一种新型矿用便携式可组网烟气监测分析仪。基于AvaSpec-2048设计了烟气监测分析电路以对烟气成分气体的体积分数进行高精度检测,采用嵌入式开发技术和ZigBee无线网络技术实现了分析仪的组网功能。测试应用结果表明,该分析仪工作稳定可靠,响应速度快,组网能力强,能很好地满足分布式多仪表联合监测的要求。     

氨法处理硫酸尾气蓝色烟雾的防治措施

介绍氨法处理硫酸尾气蓝色烟雾产生的原因和条件,分析影响蓝色烟雾形成的因素,并提出了一些防治措施。     

光化学烟雾物理模拟实验数据采集系统的研制

在光化学烟雾物理模拟的实验中,需要设计并建立一套可靠的数据采集系统,实现对实验数据的读取、分离、处理、显示、记录等操作。我们采用图形化编程语言LabVIEW编制的数据采集系统软件,能自动完成对光化学过程的反应条件和反应中各种物质浓度长时间连续采集,并能在线反映各种参数随时间的变化。本文介绍了系统的硬件组成和软件设计,以及保证系统稳定性方面采取的一些措施,并对其可用性进行检验。     

空空导弹激光引信抗云烟干扰技术研究

深入研究了某型空空导弹激光引信的抗云烟干扰性能;提出了三项有效抑制云烟干扰的措施：自动增益控制、脉冲形状识别、数字信号处理;并结合这三项技术,对该型导弹的激光引信进行了改进,设计出了一种多重处理、软硬结合的激光引信,它能较好地消除云烟的干扰、改善引战配合效率。