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181.
水罗兰对不同密度铜绿微囊藻抑制作用的研究 总被引:1,自引:0,他引:1
通过水罗兰与铜绿微囊藻共培养12 d,研究了水罗兰对低密度、高密度的铜绿微囊藻的抑制作用.结果表明,铜绿微囊藻初始光密度(OD680)分别为0.026、0.257时,水罗兰可显著抑制铜绿微囊藻的生长,使其OD680降低.水质检测结果显示,培养过程中共培养液营养盐浓度一直处于较高水平,铜绿微囊藻OD680降低及生长停滞并非因营养不足所引起.通过实验证实了水罗兰可作为铜绿微囊藻水华控制的生态修复物种. 相似文献
182.
Changsub Shim Qinbin Li Ming Luo Susan Kulawik Helen Worden John Worden Annmarie Eldering Glenn Diskin Glen Sachse Andy Weinheimer David Knapp Deedee Montzca Teresa Campos 《Atmospheric environment (Oxford, England : 1994)》2009,43(8):1540-1547
Concurrent tropospheric O3 and CO vertical profiles from the Tropospheric Emission Spectrometer (TES) during the MILAGRO/INTEX-B aircraft campaigns over the Mexico City Metropolitan Area (MCMA) and its surrounding regions were used to examine Mexico City pollution outflow on a regional scale. The pollution outflow from the MCMA occurred predominantly at 600–800 hPa as evident in O3, CO, and NOx enhancements in the in situ aircraft observations. TES O3 and CO are sensitive to the MCMA pollution outflow due to their relatively high sensitivities at 600–800 hPa. We examined O3, CO, and their correlation at 600–800 hPa from TES retrievals, aircraft measurements, and GEOS-Chem model results. TES captures much of the spatial and day-to-day variability of O3 seen in the in situ data. TES CO, however, shows much less spatial and day-to-day variability compared with the in situ observations. The ΔO3/ΔCO slope is significantly higher in the TES data (0.43) than the in situ data (0.28) due partly to the lack of variability in TES CO. Extraordinarily high ΔO3/ΔCO slope (0.81) from TES observations at 618 hPa over the Eastern U.S. was previously reported by Zhang et al. [Zhang, L., Jacob, D.J., Bowman, K.W., et al., 2006. Ozone–CO correlations determined by the TES satellite instrument in continental outflow regions. Geophys. Res. Lett. 33, L18804. 10.1029/2006GL026399.]. Thus the application of TES CO–O3 correlation to map continental pollution outflow needs further examination. 相似文献
183.
Jeremy E. Diem 《Atmospheric environment (Oxford, England : 1994)》2009,43(25):3902-3909
The purpose of this paper is to identify the atmospheric conditions associated with elevated ground-level ozone concentrations during June–August of 2000–2007 at 11 ozone-monitoring stations in the Atlanta, GA, USA metropolitan statistical area (MSA). Analyses were confined to high-ozone days (HODs), which had a daily maximum 8-h average ozone concentration in the 95th percentile of all June–August values. Therefore, each station had 36 HODs. The southeastern and far northern portions of the MSA had HODs with the highest and lowest ozone concentrations, respectively. HODs at nearly all Atlanta MSA ozone-monitoring stations were enabled by migratory anticyclones. HODs for most stations were hot, dry, and calm with low morning mixing heights and high afternoon mixing heights. All sets of HODs had daily mean relative humidities and afternoon mixing heights that, respectively, were significantly less than and significantly greater than mean values for the remaining days. Urbanized Atlanta typically was upwind of an ozone-monitoring station on its HODs; therefore, wind direction on HODs varied considerably among the stations. HODs may have been caused partially by NOx emissions from electric-utility power plants: HODs in the southern portion of the MSA were linked to air-parcel trajectories intersecting a power plant slightly northwest of Atlanta and plants in the Ohio River Valley, while HODs in the northern portion of the MSA were linked to air-parcel trajectories intersecting two large power plants slightly southeast of the Atlanta MSA. Results from this study suggest that future research in the Atlanta MSA should focus on power-plant contributions to ground-level ozone concentrations as well as the identification of non-monitored locations with potentially high ozone concentrations. 相似文献
184.
热-力耦合作用对建筑结构火灾安全的影响 总被引:4,自引:3,他引:1
结构火灾安全可以避免建筑物在火灾中坍塌.火灾热环境影响建筑结构的响应,传统的标准火灾环境有一定的局限性,不能完全适用于若干真实火灾场景.因此有必要开展真实火灾环境下建筑结构的热-力响应特性研究,发展有效的工程工具来设计经济安全的结构.近来,性能化的结构火灾安全设计评估方法和相应技术发展迅速,该文给出一种综合考虑热-力耦合作用的结构火灾安全设计评估方法及相应流程.首先通过建筑和燃料特性来预测可能的火灾热环境特性,然后再分析构件和结构的热响应和力学响应特性来判定结构是否会失效,以及可以降低热和力影响的预防失效措施.该文通过案例分析将该方法应用于某中庭钢结构屋顶的防火保护,得到经济合理的防火涂层设计,满足有关防火规范的安全等价要求. 相似文献
185.
186.
A comparison between superfine magnesium hydroxide powders and commercial dry powders on fire suppression effectiveness 总被引:1,自引:0,他引:1
Kaiqian Kuang Xin Huang Guangxuan Liao 《Process Safety and Environmental Protection》2008,86(3):182-188
The effectiveness of superfine magnesium hydroxide powders and commercial dry powder in fire suppression were compared in a laboratory-scale, immovable fire suppression apparatus. The investigation focused on their suppression effectiveness under various pressures. It likewise studied the relationship between the powders’ surface structures and their effectiveness on fire suppression. The microcosmic structure of the powders was observed by scanning electron microscope (SEM), while the Thermal Gravity Analysis (TGA) technique was used to analyze the thermal behavior of the superfine magnesium hydroxide powders. By analyzing the results, it could be concluded that the pressure, the particle size, and the microcosmic structure of the powders’ surface mainly decide the capability of the powders to extinguish the fire. Comparing this with commercial dry powders, superfine magnesium hydroxide powders extinguished the fire in less than 10 s. 相似文献
187.
188.
基于热重与因子分析的树叶试样燃烧性研究 总被引:1,自引:0,他引:1
为了研究防火树种树叶试样的热解过程,并且评价其燃烧特性,文章采用TG(Thermogravimetry)技术在空气气氛下对13种树种的树叶试样进行了实验研究,分析了其热解特征参数,并使用应用因子分析法对热解参数进行了统计分析。结果表明因子分析法用于评价防火树种的燃烧性具有较高的可靠性,燃烧性最好的树叶是交让木叶和茶叶叶,燃烧性最差的是火力楠叶、栗树叶和木荷叶。 相似文献
189.
190.