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141.
基于AGRI数据反演区域PM2.5浓度.利用6S辐射传输模式,分析气溶胶光学厚度AOD与能见度相关性,建立AOD、气溶胶标高和能见度模型;通过对大气柱AOD垂直订正,构建AOD与近地面PM2.5浓度关系的物理模型;同时引入了地面相对湿度数据.结果表明,FY-4A遥感的PM2.5浓度与地面空气质量监测站的PM2.5浓度变化趋势一致,算法计算效率较高.利用AGRI估算近地面PM2.5与地面观测网对比分析,其结果不亚于于MODIS以及VIIRS的对比结果,AGRI估算的均方根误差和相对误差较小.从季节分析,冬季近地面颗粒物浓度是影响整层大气柱AOD值的主要因素,AGRI反演结果精度较好,夏季相关系数相对于其他三个季节偏低.总体而言,采用FY-4A/AGRI反演颗粒物浓度精度可靠,有利于实现区域气溶胶全天候实时监测. 相似文献
142.
The carbendazim(MBC) hydrolyzing enzyme gene was cloned and heterologously expressed in Escherichia coli BL21(DE3) from a newly isolated MBC-degrading bacterium strain Microbacterium sp. strain djl-6F. High performance liquid chromatography-mass spectrometry(HPLC-MS)analysis revealed that purified MheI-6F protein catalyzes direct hydrolysis of MBC into2-aminobenzimidazole(2-AB) with a high turnover rate and moderate affinity(Kmof6.69 μmol/L and kcatof 160.88/min) without the need for any cofactors. The optimal catalytic condition of MheI-6F was identified as 45°C, pH 7.0. The enzymatic activity of MheI-6F was found to be diminished by metal ions, and strongly inhibited by sodium dodecyl sulfate(SDS).Through generating amino acid mutations in MheI-6F, Cys16 and Cys222 were identified as the catalytic groups that are essential for the hydrolysis of MBC. This is the first report on the biodegradation of MBC at the enzymatice level. 相似文献
143.
为实现重金属污染环境中Cr6+的生物可利用度评价,进而为Cr6+的污染治理提供可靠依据,本研究采用分子生物技术,以重金属广谱抗性菌株Cupriavidus metallidurans CH34的pMOL28质粒上铬抗性调控系统的启动子和调控蛋白基因为传感器调控元件,以北美萤火虫Photinus pyralis的萤火虫荧光素酶基因luc为报告基因构建了一种可对Cr6+生物可利用度进行检测的微生物全细胞传感器CB10,并探究了其在不同检测条下的响应特征.结果表明,微生物全细胞传感器CB10在30 min内即可响应一定浓度的Cr6+;其对Cr6+的检测最低限LOD为2μmol·L-1;当Cr6+的浓度为20~200μmol·L-1时,CB10的响应能力与Cr6+浓度线性相关,进而传感器CB10可对该范围内的Cr6+生物可利用度进行定量分析(R2=0.980 55);当重金属诱导浓度为10~50μmol·L-1时,CB10对Cr6+具有较强的响应特异性;本研究也发现,较高浓度的Pb2+、Mn2+和Sb2+也可以产生对CB10的诱导能力;诱导温度为30℃,pH为7时,CB10的响应效率最高;诱导温度为15~30℃,pH为4~7时,CB10响应能力表现稳定.CB10具备较强的响应速率、灵敏度、特异性和稳定性,具备对水体重金属进行快速检测和土壤重金属的生物可利用进行评价的潜力. 相似文献
144.
Martin J. Steinbauer Fredrik Östrand Tom E. Bellas Anna Nilson Fredrik Andersson Erik Hedenström Michael J. Lacey P. Florian Schiestl 《Chemoecology》2004,14(3-4):217-223
Summary. The autumn gum moth, Mnesampela privata
(Guenée) (Lepidoptera: Geometridae), is native to Australia
and can be a pest of plantation eucalypts. Field-collected
and laboratory-reared female autumn gum moths were
dissected to remove glands likely to contain components of
the sex pheromone. Using gas chromatography (GC) and
combined gas chromatography–mass spectrometry (GC-MS),
three compounds were identified from female extracts,
namely (3Z,6
Z,9
Z)-3,6,9-nonadecatriene, 1-hexadecanol
and 1-octadecanol (confirmed by comparison with synthetic
samples). Nonadecatriene elicited an antennal response in
male autumn gum moth during gas chromatographic
analyses combined with electroantennographic detection
(GC-EAD). In electroantennogram (EAG) recording male
M. privata antennae responded to the nonadecatriene. Nonadecatriene was synthesised via Kolbe electrolysis,
starting with (9Z,12Z,15Z)-octadeca-9,12,15-trienoic acid
(linolenic acid) and propanoic acid or via an alternative
four-step method also starting from linolenic acid. In field
trials (3Z,6Z,9Z)-3,6,9-nonadecatriene proved attractive
to male moths. Thus, we conclude that (3Z,6Z,9Z)-3,6,9-
nonadecatriene is a sex pheromone component of autumn
gum moth. This component has been identified in extracts
from other geometrids in the same subfamily, Ennominae.
However, to our knowledge this is the first example where
(3Z,6Z,9Z)-3,6,9-nonadecatriene has been found in females
and also proved attractive to male moths when presented on its
own. Our results are discussed in relation to other geometrid
pheromones. 相似文献
145.
Sulfur hexafluoride (SF6) is known as one of the most powerful greenhouse gases in the atmosphere. Reductive photodegradation of SF6 by styrene has been studied with the purpose of developing a novel remediation for sulfur hexafluoride pollution. Effects of reaction conditions on the destruction and removal efficiency (DRE) of SF6 are examined in this study. Both initial styrene-to-SF6 ratio and initial oxygen concentration exert a significant influence on DRE. SF6 removal efficiency reaches a maximum value at the initial styrene-to-SF6 ratio of 0.2. It is found that DRE increases with oxygen concentration over the range of 0 to 0.09 mol/m^3 and then decreases with increasing oxygen concentration. When water vapor is fed into the gas mixture, DRE is slightly enhanced over the whole studied time scale. The X-ray Photoelectron Spectroscopy (XPS) analysis, together with gas chromatography-mass spectrometry (GC-MS) and Fourier Transform Infrared spectroscopy (FT-IR) analysis, prove that nearly all the initial fluorine residing in the gas phase is in the form of SiF4, whereas, the initial sulfur is deposited in the form of elemental sulfur, after photodegradation. Free from toxic byproducts, photodegradation in the presence of styrene may serve as a promising technique for SF6 abatement. 相似文献
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148.
国华三河电厂烟塔SF6示踪扩散试验共确定5次试验气象窗口,每次气象窗口进行3次试验,共有12次试验取得有效数据,基本涵盖了大风、小风以及各种大气稳定度类型.不稳定条件下,风速较小时,单位源强产生的最大落地浓度大,距离近;中性条件下,风速较大时,单位源强产生的最大落地浓度居中,距离较远;稳定条件下,中等风速时,单位源强产生的最大落地浓度小,距离较远.这与模式模拟结果通常所表现的规律相一致.类推得出电厂NOx的最大落地浓度比标率〔《环境空气质量标准》(GB3095—1996)二级标准〕为6.97%,其环境影响可接受. 相似文献
149.
150.