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401.
本文阐述了国家快速反应系统的概念及其作用。以建立资源与环境快速反应系统为例,说明建立系统的必要性、系统的内容、组成及技术指示。 相似文献
402.
以一起直接式原油加热炉炉管穿孔事故为例,介绍了事故处理程序,分析了炉管穿孔的原因是由于漏点腐蚀、坑点腐蚀以及炉管管卡损坏导致的,并提出了类似事故防范对策. 相似文献
403.
蒙城地震台地磁绝对观测数据主要通过手工方式计算处理,由于内容多而繁琐,很容易出现人为错误,而且工作效率不高。本文介绍了“蒙城地震台地磁绝对观测数据处理分析软件”,该软件将绝对观测日常数据处理工作有效整合,形成了流程,提高了数据处理效率。并能够对数据进行误差统计、趋势分析等,以了解观测资料的实际状况。 相似文献
404.
Chemical characterization of fine particles from on-road vehicles in the Wutong tunnel in Shenzhen, China 总被引:1,自引:0,他引:1
Vehicle populations in China have been increasing sharply since 1990s. Vehicle emissions including various gaseous pollutants and particulate matter cause deterioration of air quality. However, measurements of particulate mater from on-road vehicles in China are scarcely reported, and thus the chemical compositions of particles emitted from vehicles in China are unknown. In this research, tunnel experiments were performed to measure PM2.5 in the Wutong tunnel, Shenzhen, China. Detailed PM2.5 chemical compositions, with organic compounds determined by GC/MS, in the tunnel were presented. Elemental carbon and organic matter composed 63% and 34% of the total PM2.5 mass in the Wutong tunnel, respectively. Alkanes, PAHs, hopanes, fatty acids, and dicarboxylic acids were the major identified organic compounds, and their source profiles in the PM2.5 in the Wutong tunnel were characterized. The comparisons of our measurements with those in the literature were also made to demonstrate the characteristics of the vehicle source profiles in the Wutong tunnel. The experimental results in this paper can improve understanding of particulate matter emitted from vehicles in China. 相似文献
405.
Riboflavin (Vitamin B2) is a natural dye-sensitizer habitually present in natural waters. Effects of riboflavin as photosensitizer on the transformation of benzo[a]pyrene (BaP) (10 microM) in the aqueous-organic solvent (water/acetonitrile/methanol 50/40/10) were investigated in this study. The photolysis half life of BaP in solution containing 50 microM riboflavin was 5 min, compared to 98 min in the absence of riboflavin. The rate of phototransformation of BaP increased as the concentration of riboflavin was raised from 10 microM to 100 microM under both natural sunlight and UVA irradiation. The half life of BaP in the presence of 50 microM riboflavin was 10.6 min and 43.1 min when exposed to visible range of natural sunlight and UVA irradiation respectively. Riboflavin decomposes under natural sunlight. Lumichrome, a principal photoproduct of riboflavin, was shown to photosensitize BaP under natural sunlight after photolysis of riboflavin. Our study indicated that other photoproducts from riboflavin, such as lumiflavin, were also involved in the phototransformation of BaP under sunlight when riboflavin diminished. The major photoproducts in the photolysis of BaP were identified as 1,6-benzo[a]pyrene-dione, 3,6-benzo[a]pyrene-dione, 6,12-benzo[a]pyrene-dione by using high performance liquid chromatography (HPLC). All these products were detected in the samples which were irradiated under different light sources and in the presence or absence of riboflavin. The possible phototransformation mechanism was discussed. 相似文献
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为了研究新型溴代阻燃剂FM550的生态风险,以罗非鱼为模式生物,配制添加不同浓度FM550(0、10、100和400ng·g~(-1))的饲料,将罗非鱼暴露56 d后,研究不同暴露剂量条件下FM550对罗非鱼甲状腺激素以及血清生理生化指标的影响。研究表明,经不同浓度的FM550暴露56 d后,罗非鱼的基础生长数据并无显著变化,但罗非鱼的甲状腺激素水平发生改变,具体表现为高剂量的FM550暴露可以使罗非鱼血清中的三碘甲状腺原氨酸(T3)、游离三碘甲状腺原氨酸(FT3)含量降低,四碘甲状腺原氨酸(T4)、游离四碘甲状腺原氨酸(FT4)含量升高。同时,FM550的暴露还可以导致罗非鱼的脂代谢改变,具体变化为血清总胆固醇(TC)、甘油三酯(TG)含量降低,高密度脂蛋白(HDL-C)含量升高,低密度脂蛋白(LDL-C)含量降低。不同剂量的FM550暴露对罗非鱼的全血生化指标并无影响。 相似文献
410.
Zhu Jun Fu Qingling Qiu Guohong Liu Yurong Hu Hongqing Huang Qiaoyun Violante Antonio 《Environmental Chemistry Letters》2019,17(3):1271-1280
Environmental Chemistry Letters - The sorption of heavy metals by soil constituents reduces the absorption of these pollutants by crops and vegetables, and thus limit food contamination. Low... 相似文献