Quantification of multi-antibiotic resistant opportunistic pathogenic bacteria in bioaerosols in and around a pharmaceutical wastewater treatment plant

Pharmaceutical wastewater treatment plants(WWTPs) are thought to be a "seedbed" and reservoirs for multi-antibiotic resistant pathogenic bacteria which can be transmitted to the air environment through aeration. We quantified airborne multi-antibiotic resistance in a full-scale plant to treat antibiotics-producing wastewater by collecting bioaerosol samples from December2014 to July 2015. Gram-negative opportunistic pathogenic bacteria(GNOPB) were isolated, and antibiotic susceptibility tests against 18 commonly used antibiotics, including 11 β-lactam antibiotics, 3 aminoglycosides, 2 fluoroquinolones, 1 furan and 1 sulfonamide, were conducted.More than 45% of airborne bacteria isolated from the pharmaceutical WWTP were resistant to three or more antibiotics, and some opportunistic pathogenic strains were resistant to 16 antibiotics, whereas 45.3% and 50.3% of the strains isolated from residential community and municipal WWTP showed resistance to three or more antibiotics. The calculation of the multiple antibiotic resistance(MAR) index demonstrated that the air environment in the pharmaceutical WWTP was highly impacted by antibiotic resistance, while the residential community and municipal WWTP was less impacted by antibiotic resistance. In addition, we determined that the dominant genera of opportunistic pathogenic bacteria isolated from all bioaerosol samples were Acinetobacter, Alcaligenes, Citrobacter, Enterobacter, Escherichia, Klebsiella, Pantoea, Pseudomonas and Sphingomonas. Collectively, these results indicate the proliferations and spread of antibiotic resistance through bioaerosols in WWTP treating cephalosporin-producing wastewater, which imposed a potential health risk for the staff and residents in the neighborhood, calling for administrative measures to minimize the air-transmission hazard.     

变电站常用金属的大气腐蚀行为及其防护

综述了变电站常用金属的腐蚀类型及研究现状。对于不锈钢、铝及铝合金,海洋大气中的Cl~-引起钝化膜破裂,当其浓度超过临界浓度[Cl~-]_(pit),发生点蚀。对于铜及铜合金,工业大气中的SO~2腐蚀作用极为明显。对于锌及锌合金,Cl~-增强表面薄液膜的导电性从而加剧其腐蚀。因此,高润湿时间和高Cl~-是滨海变电站大气腐蚀的主要原因。     

等离子喷涂 YSZ 涂层瞬态超高温冲蚀性能研究

目的研究等离子喷涂YSZ涂层的瞬态超高温烧蚀性能。方法借助超音速火焰喷涂设备实现超高温高速火焰,对等离子喷涂YSZ涂层进行瞬态冲蚀,通过火焰中加送氧化铝颗粒模拟对涂层的高温冲刷。采用常规手段评价涂层的抗瞬态超高温冲蚀性能,并对冲蚀部位进行微观观察,探讨涂层的失效机理。结果在3000 K、不添加砂粒的条件下,火焰冲击3 s后钢基体材料表面发生沸腾;喷涂0.6 mm YSZ的试样在火焰冲击60 s后涂层完好。在3000 K、添加砂粒的条件下,火焰冲击3 s后钢基体材料被冲刷出约1.0 mm深坑;喷涂0.6 mm YSZ试样的涂层被火焰冲刷剥落,但基体未受明显损伤;喷涂1 mm YSZ的试样,试验后仍保留部分涂层。结论在3000 K高温瞬态冲蚀条件下,热喷涂1 mm厚YSZ涂层可对材料表面形成有效防护。     

人工湿地去除畜禽养殖废水中磺胺类抗生素抗性基因研究

采用垂直潜流人工湿地研究了畜禽养殖废水中磺胺类抗生素抗性基因(ARGs)在人工湿地中的去除及累积情况.结果表明,畜禽养殖废水中的3种磺胺类ARGs(sul Ⅰ,sul Ⅱ及sul Ⅲ)的平均绝对含量分别为1.15×1010、7.51×1010及7.51×107 copies/L.通过湿地系统处理后sul Ⅰ、sul Ⅱ及sul Ⅲ的平均去除率分别为89％、88％及84％.在系统运行末期,湿地表层土壤和底层土壤中sul Ⅰ、sul Ⅱ及sul Ⅲ的绝对拷贝数和相对表达量均有明显的升高.结果表明,人工湿地系统可有效降低畜禽养殖废水中ARGs含量.     

含缺陷油套管的抗弯曲特性研究

本研究选用J55油套管，用人工缺陷法在外径为73mm的油套管外表面预制了缺陷，通过三点弯曲对称加载试验，研究了缺陷管的抗弯强度，对改进的NSC准则进行实验检验。结果表明，在缺陷角较小时，改进的NSC准则能给出与试验数据接近的预测结果，但对于在缺陷角较大的情形，预测结果却不理想。根据试验结果，本文进一步提出了一个含有缺陷几何参量的新公式。新公式能很好地预测含缺陷管的抗弯曲能力。     

国家地震紧急救援训练基地可控地震废墟设计(Ⅱ)——功能设计

地震往往给人类社会带来巨大的财产损失和人员伤亡，专业化的地震紧急救援能够及时应对地震灾害，最大限度减少人民生命财产损失，是防震减灾体系不可或缺的组成部分。国家紧急救援训练基地的建立就是为了训练具有专业水平的地震紧急救援队伍和人员。针对建筑物在地震中的破坏倒塌模式，借鉴国际先进地震搜索救援经验，进行了在各种地震废墟中紧急搜索和救援的方案设计以及国家地震紧急救援训练基地可控地震废墟部分的功能设计。     

现代城市抗震减灾的若干问题及其对策

针对我国城市抗震减灾工作的现状，指出了其中存在的一些主要问题，并提出了相应的建议和对策。同时，论述了当前抗震减灾工作所涉及的新形势、新概念和新内涵，阐明了做好防震减灾工作的重要性和紧迫性。     

国家地震紧急救援训练基地可控地震废墟设计(II)——功能设计

地震往往给人类社会带来巨大的财产损失和人员伤亡,专业化的地震紧急救援能够及时应对地震灾害,最大限度减少人民生命财产损失,是防震减灾体系不可或缺的组成部分。国家紧急救援训练基地的建立就是为了训练具有专业水平的地震紧急救援队伍和人员。针对建筑物在地震中的破坏倒塌模式,借鉴国际先进地震搜索救援经验,进行了在各种地震废墟中紧急搜索和救援的方案设计以及国家地震紧急救援训练基地可控地震废墟部分的功能设计。     

Laboratory Measurement of Dry Deposition of Ozone onto Northern Chinese Soil Samples

We used laboratory experiments to investigate surface resistance (R _c) to dry deposition of ozone (O₃) on different types of soil samples collected from the arid deserts and the Loess Plateau of northern China. Furthermore, we measured the factors that affected R _c, which depends on the physical and chemical interaction between trace constituents and the deposition surface, and evaluated deposition velocity (V _d). There was little influence of geometric surface area, soil weight, or O₃ concentration on V _d of O₃. The effect of relative humidity (RH) (i.e. moisture content of the soil) on O₃ uptake was in agreement with results reported in the literature: a distinct RH dependence of V _d and little uptake under water-saturated conditions were observed. R _c values for all the soil samples examined were in the range 0.21–3.3 s mm⁻¹ and were exponentially related to the surface area of the particles and the organic carbon content of each soil sample at RH of both <10 and 60%.     

Wet Strength and Water Resistance of Modified Soy Protein Adhesives and Effects of Drying Treatment

Soy protein isolate (SPI) was modified using sodium dodecyl sulfate (SDS) and guanidine hydrochloride (GuHCl). Adhesion performance of the modified SPI on fiberboard was studied. The Water-soluble mass of the modified SPI adhesives was examined following modified ASTM D5570. The SDS-modified SPI containing 91% protein had a water-soluble mass of 1.7%. To be considered a water-resistant adhesive, the water-soluble mass of adhesive should be less than 2%. The wet shear strength test showed 100% cohesive failure within fiberboard, indicating that the modified SPI has good water resistance. The effect of drying treatment on adhesion performance of the SDS-modified SPI on fiberboard was then investigated. Drying treatment significantly affected the final adhesion performance. Shear strength did not change much, but the percentage of cohesive failure within fiberboard increased markedly as drying temperature increased. All the unsoaked, soaked, and wet specimens glued by the adhesives treated at 70° or 90°C had 100% cohesive failure within fiberboard. Viscosity also increased greatly with an increase in drying temperature. This information will be useful in developing low-cost adhesive processing system in the future.