多孔球三相流化床冷态试验的研究

对多孔球为填料的三相流化床进行冷态试验研究,研究不同工况下气体空塔流速、填料静止高度、喷淋密度等因素对流化床阻力特性和脱硫效率的影响.试验表明,用多孔球替代空心球做填料,不仅可以消除空心球在流化过程中出现的问题,还可以适当提高脱硫效率.     

两个酸模种群对Cu2+积累和抗性的差异

利用盆培实验,对种子分别来源于污染区和非污染区的两个酸模种群在Cu2 胁迫下的抗性和生物蓄积性进行了比较研究。在Cu2 胁迫下,来源于污染区的酸模种群根长和生物量受到的抑制作用明显地低于非污染区种群。当Cu2 处理浓度≥250μmol·L-1时,污染区种群的抗性指数显著高于非污染区种群(P<0.01)。在Cu2 处理浓度为50、250、500μmol·L-1时,污染区种群地上部分的铜质量分数均显著低于同处理组中的非污染种群(P<0.05)。这些结果表明酸模的污染区种群较非污染区种群对铜有着更强的抗性,并且污染区种群存在限制Cu2 向地上部分运输的机制,而这种限制运输的机制可能对提高铜的抗性起到重要作用。     

电源变压器温升试验中（绕组法）的影响因素及不确定度的评估

本文中探讨的是根据绕组法计算电源变压器绕组温升的试验方法,以及对整个试验过程中环境、仪器设备、仪表、人为因素所引起的误差等对最终试验结果的影响,并对其测量不确定度进行评估。     

Antibiotic resistant bacteria/genes dissemination in lacustrine sediments highly increased following cultural eutrophication of Lake Geneva (Switzerland)

This study investigates faecal indicator bacteria (FIB), multiple antibiotic resistant (MAR), and antibiotic resistance genes (ARGs), of sediment profiles from different parts of Lake Geneva (Switzerland) over the last decades. MARs consist to expose culturable Escherichia coli (EC) and Enterococcus (ENT) to mixed five antibiotics including Ampicillin, Tetracycline, Amoxicillin, Chloramphenicol and Erythromycin. Culture-independent is performed to assess the distribution of ARGs responsible for, β-lactams (blaTEM; Amoxicillin/Ampicillin), Streptomycin/Spectinomycin (aadA), Tetracycline (tet) Chloramphenicol (cmlA) and Vancomycin (van). Bacterial cultures reveal that in the sediments deposited following eutrophication of Lake Geneva in the 1970s, the percentage of MARs to five antibiotics varied from 0.12% to 4.6% and 0.016% to 11.6% of total culturable EC and ENT, respectively. In these organic-rich bacteria-contaminated sediments, the blaTEM resistant of FIB varied from 22% to 48% and 16% to 37% for EC and ENT respectively, whereas the positive PCR assays responsible for tested ARGs were observed for EC, ENT, and total DNA from all samples. The aadA resistance gene was amplified for all the sediment samples, including those not influenced by WWTP effluent water. Our results demonstrate that bacteria MARs and ARGs highly increased in the sediments contaminated with WWTP effluent following the cultural eutrophication of Lake Geneva. Hence, the human-induced changing limnological conditions highly enhanced the sediment microbial activity, and therein the spreading of antibiotic resistant bacteria and genes in this aquatic environment used to supply drinking water in a highly populated area. Furthermore, the presence of the antibiotic resistance gene aadA in all the studied samples points out a regional dissemination of this emerging contaminant in freshwater sediments since at least the late nineteenth century.     

Gene expression profiles in the testis associated with testis-ova in adult Japanese medaka (Oryziaslatipes) exposed to 17α-ethinylestradiol

The occurrence of oocytes in the testis (testis-ova) of several fish species is often associated with exposure of estrogenic chemicals. However, induction mechanisms of the testis-ova remain to be elucidated. To develop marker genes for detecting testis-ova in the testis, adult male medaka were exposed to nominal concentration of 100 ng L⁻¹ of 17α-ethinylestradiol (EE2) for 3-5 weeks, and 800 ng estradiol benzoate (EB) for 3 weeks (experiment I), and a measured concentration of 20 ng L⁻¹ EE2 for 1-6 weeks (experiment II). Histological analysis was performed for the testis, and microarray analyses were performed for the testis, liver and brain. Microarray analysis in the estrogen-exposed medaka liver showed vitellogenin and choriogenin as estrogen responsive genes. Testis-ova were induced in the testis after 4 weeks of exposure to 100 ng L⁻¹ EE2, 3 weeks of exposure to 800 ng EB, and 6 weeks of exposure to 20 ng L⁻¹ EE2. Microarray analysis of estrogen-exposed testes revealed up-regulation of genes related to zona pellucida (ZP) and the oocytes marker gene, 42Sp50. Using quantitative RT-PCR we confirmed that Zpc5 gene can be used as a marker for the detection of testis-ova in male medaka.     

四环素抗生素对污泥中四环素抗性基因丰度和表达水平的作用影响

为研究四环素(TC)抗生素对其抗性基因(TC-ARGs)转录表达的作用影响,以从活性污泥中筛选获得的四环素抗性细菌(TRB)作为研究对象,采用荧光定量PCR和逆转录PCR方法检测了7种TC-ARGs,包括tet A、tet C、tet G、tet M、tet O、tet W和tet X基因的丰度和表达水平,并探讨了TC与TC-ARGs丰度及其表达水平之间的相关关系.结果表明,在整个培养周期内,tet A、tet G和tet W基因丰度随TC暴露浓度的增大总体呈现上升趋势,但其余TC-ARGs基因丰度整体波动较大. TC胁迫对不同TC-ARGs的转录表达水平作用影响差别较大,其中,tet A基因表达水平相对稳定,且随TC浓度的升高而上调,在TC浓度为100 mg·L^-1时,其上调倍数高达5. 3倍.在短期(1 d) TC胁迫下,TC-ARGs转录表达水平随TC浓度的升高整体呈现上调趋势.由相关性分析可知,tet A和tet W基因丰度与其转录表达水平之间存在显著的线性相关性,表明其基因丰度可在一定程度上衡量和评价其抗性表达水平,进而反映其功能活性和环境风险.     

雷管内部爆轰波压力测量技术

利用锰铜压阻法对雷管内部不同截面的爆压直接进行测量 ,通过实验实测 ,得到了 8#雷管内部 3个截面处的爆轰压力数据。最后对实验中出现的问题及误差产生的原因进行了较为详细的分析     

香根草人工湿地处理生活污水的试验研究

通过建立香根草人工湿地系统,研究该系统对生活污水的COD、TP、TN的处理效果以及系统的耐污性。在水力停留时间(HRT)为6h的条件下,COD、TP、TN的去除率分别为63.5%、88.3%、72.4%。研究表明,香根草人工湿地系统对城镇生活污水具有较好的净化效果,且系统在该试验条件下耐污性良好。     

基于SVM的矿井通风阻力系数影响因素分析与预测

矿井通风阻力系数是通风安全最重要的基础参数之一,为了实现矿井通风阻力系数简单准确地预测,提出了利用支持向量机（SVM）来预测矿井通风阻力系数的方法。通过分析影响因子与矿井通风阻力系数的相关性关系,并利用MATLAB逐步建立单影响因素与矿井通风阻力系数、多影响因素与矿井通风阻力系数之间的SVM预测模型,对比分析各预测模型的相对误差,确定最佳矿井通风阻力系数预测模型,即当输入模型影响因素为巷道断面积、周长和支护方式时,预测相对误差小于10%的样本数占测试样本的76%,相对误差小于20%的样本数占测试样本的90%。结果表明:该预测方法在矿井通风阻力系数预测中是可行的,并具较高的准确性。     

阴角邻面火灾作用下L型钢管混凝土柱耐火极限研究

运用有限元软件ABAQUS计算L形带肋钢管混凝土柱阴角相邻两面受火全过程下的耐火极限,分析了阴角邻面受火方式下构件内部温度场和应力场的变化规律,在此基础上分析荷载比、宽厚比、计算长度、加劲肋纵向间距、荷载偏心率、荷载角等参数对耐火极限的影响规律。数据表明:荷载比、计算长度对构件耐火极限影响较大,随着荷载比和计算长度的增大,耐火极限基本呈线性下降;加劲肋间距对构件耐火性能影响较小;由于L形柱的特殊形式,偏心荷载对耐火极限的影响规律较复杂,荷载作用点偏向低温区可以提高耐火极限。