数学模拟在污水处理厂节能减排中的应用和发展

在国内外节能减排的大背景下,污水处理厂面临着巨大的提标改造和节能减排压力。基于活性污泥数学模型的数学模拟技术在国内外许多污水处理厂的模拟仿真、运行诊断与工艺优化、升级评估、节能减排等方面得到广泛的应用,文章主要介绍了数学模拟技术在污水处理厂节能减排方面的发展和应用情况,并提出今后国内的主要研究方向。     

Cypermethrin has the potential to induce hepatic oxidative stress, DNA damage and apoptosis in adult zebrafish (Danio rerio)

Cypermethrin (CYP), a widely used Type II pyrethroid pesticide, is one of the most common contaminants in the freshwater aquatic system. We studied the effects of CYP exposure on the induction of hepatic oxidative stress, DNA damage and the alteration of gene expression related to apoptosis in adult zebrafish. Hepatic mRNA levels for the genes encoding antioxidant proteins, such as Cu/Zn-Sod, Mn-Sod, Cat, and Gpx, were significantly upregulated when zebrafish were exposed to various concentrations of CYP for 4 or 8 days. In addition, the main genes related to fatty acid β-oxidation and the mitochondrial genes related to respiration and ATP synthesis were also significantly upregulated after exposure to high concentrations (1 and 3 μg L⁻¹) of CYP for 4 or 8 days. Moreover, in a comet assay of zebrafish hepatocytes, tail DNA, tail length, tail moment and Olive tail moment increased in a concentration-dependent manner. The significant induction (p < 0.01) of all four parameters observed with CYP concentrations of 0.3 μg L⁻¹ or higher suggests that heavy DNA damage was induced even at low levels. Furthermore, several apoptosis- related genes, such as p53, Apaf1 and Cas3, were significantly upregulated after CYP exposure, and Bcl2/Bax expression ratio decreased, especially in groups treated with 1 and 3 μg L⁻¹ CYP for 8 days. Taken together, our results suggested that CYP has the potential to induce hepatic oxidative stress, DNA damage and apoptosis in zebrafish. This information will be helpful in fully understanding the mechanism of aquatic toxicology induced by CYP in fish.     

Estimation and characterization of PCDD/Fs, dl-PCBs, PCNs, HxCBz and PeCBz emissions from magnesium metallurgy facilities in China

Magnesium production is considered to be one potential source of unintentional persistent organic pollutants (unintentional POPs). However, studies on the emissions of unintentional POPs from magnesium metallurgy are still lacking. Emissions of unintentional POPs, such as polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), dioxin-like polychlorinated biphenyls (dl-PCBs), polychlorinated naphthalenes (PCNs), hexachlorobenzene (HxCBz) and pentachlorobenzene (PeCBz) are covered under the Stockholm Convention. In this study, these emissions were investigated through a magnesium smelting process. Stack gas and fly ash samples from a typical magnesium plant in China were collected and analyzed to estimate the emissions of unintentional POPs from magnesium metallurgy. Emissions factors of 412 ng TEQ t⁻¹ for PCDD/Fs, 18.6 ng TEQ t⁻¹ for dl-PCBs, 3329 μg t⁻¹ for PCNs, 820 μg t⁻¹ for HxCBz, and 1326 μg t⁻¹ for PeCBz were obtained in 2009. Annual emissions from magnesium metallurgy in China were estimated to be 0.46 g WHO-TEQ for PCDD/Fs and dl-PCBs, 1651 g for PCNs, 403 g for HxCBz and 653 g for PeCBz, respectively.     

基于ATG实报的空中颠簸预防管理系统设计

在对颠簸伤害事件原因分析的基础上,设计了基于ATG实报的空中颠簸预防管理系统,该系统设计主要包括:开发QAR计算EDR程序,通过EDR指标提高颠簸预报精度;开发颠簸管理平台,实现颠簸信息的有效传递;利用ATG技术使颠簸预报向颠簸实报提升,提高颠簸信息的实时性。该解决方案可实现空地高精度颠簸风险实时自动预警,有效降低颠簸伤害。     

Estimation of chlorophyll a content in inland turbidity waters using WorldView-2 imagery: a case study of the Guanting Reservoir,Beijing, China

Complex optical properties, such as non-pigment suspension and colored dissolved organic matter (CDOM), make it difficult to achieve accurate estimations of remotely sensed chlorophyll a (Chla) content of inland turbidity. Recent attempts have been made to estimate Chla based on red and near-infrared regions where non-pigment suspension and CDOM have little effect on water reflectance. The objective of this study is to validate the applicability of WV-2 imagery with existing effective estimation methods from MERIS when estimating Chla content in inland turbidity waters. The correlation analysis of measured Chla content and WV-2 imagery bands shows that the Chla sensitive bands of WV-2 are red edge, NIR 1, and NIR 2. The coastal band is designed for seawater Chla detection. However, the high correlation with turbidity data and low correlation with Chla made coastal band unsuitable for estimating Chla in inland waters. The high-resolution water body images were extracted by combining the spectral products (NDWI) with the spatial morphological products (sobel edge detection). The estimation results show that the accuracy of the single band and NDCI is not as good as the two-band method, three-band method, stepwise regression algorithm (SRA) and support vector machines (SVM). The SVM estimation accuracy was the highest with an R², RMSE, and URMSE of 0.8387, 0.4714, and 19.11%, respectively. This study demonstrates that the two-band and three-band methods are effective for estimating Chla in inland water for WV-2 imagery. As a high-precision estimation method, SVM has great potential for inland turbidity water Chla estimation.     

智能建筑控制系统安全体系研究

智能建筑控制系统在设计时为了满足可靠性、实时性和灵活性等性能需求,忽略了信息安全的考虑,随着越来越多的计算机技术和网络通信技术应用于智能建筑控制系统中,控制网络的安全问题凸现出来.在深入分析智能建筑控制系统所面临的各种安全威胁基础上,设计了一种智能建筑控制系统的安全体系,提出了针对建筑智能化系统面临的各种安全威胁所应采取的安全机制,确保智能建筑控制信息的机密性、系统的可用性和数据的完整性.     

火旋风模拟实验中热电偶测温辐射误差修正方法研究

辐射传热误差是浮力火羽流和火旋风热电偶温度测量中需要重点考虑的误差来源.该文利用火旋风模拟实验台开展火旋风温度测量实验并进行辐射误差分析,通过在同一测点布设多根不同直径热电偶,基于不同热电偶测温误差的对比,分析了几种多测量端温度误差修正方法,并通过两种粗细热电偶组合来检验不同修正方法的可靠性.     

宜兴市臭氧和挥发性有机物的浓度特征研究

于2016年对宜兴市大气挥发性有机物(VOCs)和臭氧(O_3)的变化特征进行了分析。结果表明,宜兴市O3年均值为62.92μg/m~3,其中冬季值最低(31.19μg/m~3),夏季值最高(94.96μg/m~3)。φ(VOCs)为(11.00~42.45)×10~(-9),其中丙酮(12.7%)、乙酸乙酯(8.8%)和丙烯(3.3%)等在VOCs中占比位于前3位。各站点φ(甲苯)/φ(苯)2,全年的φ(甲苯)/φ(苯)φ(乙苯)/φ(苯)φ(间、对二甲苯)/φ(苯)。指出VOCs主要来源为有机溶剂和道路交通,并受到一定的外来输送影响。各站点φ(VOCs)/φ(NOx)为0.94~2.44,O3处于VOCs敏感区。     

不同季节常州市气团来源差异性研究

利用NCEP全球再分析资料和HYSPLIT4模式,计算了2014年常州市不同季节的气流后向轨迹。结合聚类分析方法和常州市PM_(2.5)、PM_(10)、SO_2、NO_2和O_3监测数据,分析了各季节不同类型气团来源对各污染物浓度的影响。结果表明,常州市的气团来源具有明显的季节性特征,春季以东北偏东方向的气团为主,西南气流对应的PM_(2.5)和PM_(10)平均值较高,分别为93和157μg/m3;夏季受海洋型气团影响为主,东南气团对应的O_3平均值较高,为90μg/m3。秋季西北气流增多,其对应的PM_(2.5)和PM_(10)平均值较高,分别为71和107μg/m3,东南气团对应的SO_2和NO_2平均值较高,分别为40和43μg/m3;冬季受大陆型气团影响更显著,京津冀等北方气团和杭州湾方向的南面气团对应的PM_(2.5)和PM_(10)值较高,分别在100和150μg/m3以上。冬季随着空气污染加重,本地和本区域的气团逐渐占主导地位,说明加强长三角区域内的污染物协同管控,对于改善空气质量会具有明显的效果。     

TBT染毒导致的大鼠脂质过氧化与DNA损伤

采用连续灌胃的方式对SD大鼠进行三丁基锡(TBT)染毒,剂量为0、0.1、1.0、和10.0 mg·kg-1,分别在暴露的第4d、8d处死动物,取肝脏检测丙二醛(MDA)含量,取外周血检测淋巴细胞DNA损伤.结果表明,TBT暴露第4d时,淋巴细胞尾长和尾相显著升高(p＜0.001),而各浓度组的MDA含量与对照组相比都没有显著性差异;第8d时MDA含量随TBT暴露浓度的升高呈上升的趋势,高浓度组(10.0 mg·kg-1)和对照组相比有显著性差异(p＜0.05),淋巴细胞尾长和尾相在各浓度组与对照组相比都有显著性升高,但高浓度组升高的趋势稍下降.研究结果提示TBT染毒对大鼠有脂质过氧化和DNA损伤作用.