Cytochrome P450 BM3 of Bacillus megaterium—A possible endosulfan biotransforming gene

Computing chemistry was applied to understand biotransforrnation mechanism of an organochlorine pesticide, endosulfan. The stereo specific metabolic activity of human CYP-2B6 （cytochrome P450） on endosulfan has been well demonstrated. Sequence and structural similarity search revealed that the bacterium Bacillus megaterium encodes CYP-BM3, which is similar to CYP-2B6. The functional similarity was studied at organism level by batch-scale studies and it was proved that B. megaterium could metabolize endosulfan to endosulfan sulfate, as CYP-2B6 does in human system. The gene expression analyses also confirmed the possible role of CYP-BM3 in endosulfan metabolism. Thus, our results show that the protein structure based in-silico approach can help us to understand and identify microbes for remediation strategy development. To the best of our knowledge this is the first report which has extrapolated the bacterial gene for endosulfan biotransformation through in silico prediction approach for metabolic gene identification.     

PA6/煤系高岭土复合材料的制备与性能

用不同硅烷类偶联剂和钛酸酯偶联剂处理煤系高岭土,研究了煤系高岭土活化指数的变化,制备了PA6／煤系高岭土复合材料,研究了材料的力学性能和结晶行为。结果表明：在PA6中填充用偶联剂处理的煤系高岭土,可起到增强作用,其中钛酸脂偶联剂NDZ101效果较好,其合适用量为1％,经偶联剂处理的煤系高岭土比未处理的煤系高岭土具有更好的增强效果;煤系高岭土使尼龙6的结晶温度升高,结晶速度加快。     

Identification, synthesis and activity of sex pheromone gland components of the autumn gum moth (Lepidoptera: Geometridae), a defoliator of Eucalyptus

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.     

Photoreductive degradation of sulfur hexafluoride in the presence of styrene

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.     

模拟矿井水中部分离子对蚕豆遗传性损伤的研究

用矿井水作蚕豆微核实验,讨论了F^-、Hg^2＋和Cr^6＋单一及复合污染对蚕豆微核的影响。结果表明,F^-、Hg^2＋和Cr^6＋单一污染均对微核产生显著影响,随着氟化物浓度和Cr6＋浓度的增加,微核率呈上升趋势;随着Hg^2＋和Cr^6＋浓度增加,微核率呈先上升后下降的趋势。两因子方差分析显示,F^-和Hg^2＋复合污染对蚕豆微核率有显著影响。     

烟塔合一排放的SF_6示踪扩散试验

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.     

碱消解法测定固体废物中六价铬的研究

用碱性消解液对固体废物进行预处理,所得消解溶液用火焰原子吸收光谱法进行测定。结果表明:该方法在0.00~8.00mg/L范围内呈良好线性关系,检出限为2.00mg/kg(样品以计2.5g计)。实际样品测定的RSD为1.37%~9.35%,加标回收率为85.5%~125%。消解溶液同时用二苯碳酰二肼分光光度法进行测定,结果显示,两种方法测定的结果没有显著差异,进一步说明了采用火焰原子吸收光谱法测定固体废物中Cr6+的准确性与可靠性。     

六车道高速公路交通噪声预测模型研究

在目前的公路交通噪声预测中,因道路类型不同和采用的预测模型不同,预测出来的结果会有所差异,长久以来以《公路建设项目环境影响评价规范(试行(JTJ 005-96)》的模型应用最多。对于六车道高速公路噪声的预测,考虑将六车道分成两个三车进行道叠加预测和把六车道作为一个整体进行预测这两种方式来进行,并与噪声实测值进行比较,可为今后高速公路六车道交通噪声的预测提供一定的参考依据。     

燃烧对SF6扩散影响的示踪试验研究

根据2010年9月,在北京某试验场开展的一系列SF6示踪扩散试验,以及获取的SF6浓度空间分布数据,以高斯模式和计算机拟合为基础,计算出SF6浓度分布在水平和垂直方向的扩散标准差、地面峰值浓度等参数,分析、总结出了在典型地理(山区和平原连接处)和边界层条件下燃烧对SF6扩散的影响。通过试验及分析可知,燃油对试验区域气流产生了明显扰动,但具体原理有待于进一步分析。     

“三门六科”水质基准最少毒性数据需求原则

MTDR(最少毒性数据需求)是水质基准推算中数据应用的重要原则. 以重金属Pb2+、Cd2+、Cu2+、Zn2+、Hg2+、Cr6+为例,在广泛搜集物种毒性数据的基础上,通过数据比较分析,初步研究了我国水生生物基准的MTDR. 结果表明:Hg2+、Pb2+和Cu2+基于“三门六科”推导的急性基准值与基于美国“三门八科”MTDR的推算结果相近,分别相差20.5%、25.2%和33.3%;Cd2+、Zn2+和Cr6+的计算结果差别较为明显,表明相对于美国“三门八科”MTDR,在我国生物毒性数据缺乏的情况下,“三门六科”MTDR对于部分污染物基本可行,但仍具有一定的不确定性. “三门六科”包括鲤科、除鲤科外的另一科鱼类(冷水鱼优先)、两栖类、浮游甲壳类、昆虫类和环节动物类.