Spatial variability of metallic and organic contamination of anguilliform fish in New Caledonia

New Caledonia is one of the main hot spots of biodiversity on the planet. Large amounts of contaminants are discharged into the lagoon as a result of increasing anthropogenic activities such as intense mining, urbanization, and industrialization. Concentrations of 14 trace elements and 26 persistent organic pollutants (POPs: PCBs and pesticides) were measured in the muscles of two anguilliform fish species, over a coast to barrier reef gradient in two lagoon areas differently exposed to anthropic disturbances. This study emphasizes the high trace element contamination status of anguilliform fish and also highlights slight but perceptible organic pollution. The contamination extends throughout the lagoon, from coast to barrier reef, even in areas remote from emission points. High levels of trace elements, especially those linked to mining activities (i.e., Co, Cr, Fe, Mn, and Ni), were detected in coastal sites. Furthermore, the large dispersion of most POPs throughout the entire lagoon poses the question of their potential toxicity on marine organisms from numerous habitats. Our results underline the need for long-term monitoring of various contaminants over large spatial and time scales.     

Hydrodynamics and bed stability of open channel flows with submerged foliaged plants

In this work we investigate experimentally and numerically the flow structure around foliaged plants deployed in a channel with gravels on the bed under submerged and barely submerged conditions. Velocity and Reynolds stress were measured by using a NORTEK Vectrino profiler. Visual observation shows that the initial motion of gravels is easier to be triggered under the condition of flow with barely submerged vegetation. This is confirmed by the measured velocity, Reynolds stress and total kinetic energy (TKE) profiles. The velocity exhibits a speed up in the near-bed region, and the associated Reynolds stress and TKE increase there. A 3D numerical model is then verified against the experiments and used to investigate systematically the effect of degree of submergence of foliaged plants on the channel bed shear stress. The results show that the maximum bed shear stress occurs when the foliage is situated slightly below the water surface, which can enhance channel bed instability.     

用化工污泥制曝气生物滤池填料

用化工污泥制备了曝气生物滤池填料（简称填料），考察了制备条件对填料性能的影响，对填料的结构和形貌进行了SEM表征。实验结果表明，在m（干化污泥）∶m（页岩）=0.5、预热温度350 ℃、预热时间20 min、焙烧温度1 150 ℃、焙烧时间10 min的最佳制备条件下，填料的吸水率为7.14%，堆密度为785.2 kg/cm³。表征结果显示，填料的表面粗糙，内部含有丰富的孔隙结构，有利于微生物生长繁殖。填料的重金属浸出值和有机毒物浸出值远低于GB 5058.3—2007《危险废物鉴别标准-浸出毒性鉴别》中给出的含量限值。将填料用于模拟废水的处理，COD和NH₃-N的去除率分别达到92%和65%。用化工污泥制填料的成本低，仅为800 元/t。     

环境污染责任保险的发展及对策研究

本文从《中华人民共和国保险法》出发介绍了环境污染责任保险的特点,从环境权理论、无过错责任理论、侵权责任社会化理论和风险可保性理论四个方面,厘清了环境污染责任保险的理论基础;阐述了国外的发展历程以及国内的发展现状,分析了环境污染责任保险在我国发展存在的问题,提出了可以通过专项课题研究解决环境污染责任保险发展道路上的政策和技术难题,采取稳步推进、扩大承保面、政府支持和市场竞争等方式完善环境污染责任保险,为国内日益严重的企业环境风险问题提供绿色金融方面的解决方案,缓解社会矛盾,减轻政府的管理压力。     

三维混凝土Cap模型在OpenSees中的实现

综述了由Hofstetter G和Simon J C提出的经典三维混凝土非光滑多屈服面塑性本构模型,即Cap模型,详述了此模型的算法和流程,并将此模型在通用非线性有限元软件OpenSees中编程实现。对Cap模型上每个作用区域使用最近点投影法计算得到其应力,并计算得到此模型的一致切线模量。将Cap模型应用于一个二维混凝土重力坝非线性动力响应分析,验证了此模型的稳定性和工程实用性。Cap模型的实现,将OpenSees功能拓展到三维混凝土结构的数值分析中,拓展了OpenSees的计算能力和分析功能,使其可用于混凝土重力坝等大型水利工程结构的非线性动力计算分析。     

Production of anti-amoxicillin ScFv antibody and simulation studying its molecular recognition mechanism for penicillins

The molecular recognition mechanism of an antibody for its hapten is very interesting. The objective of this research was to study the intermolecular interactions of an anti-amoxicillin antibody with penicillin drugs. The single chain variable fragment (ScFv) antibody was generated from a hybridoma cell strain excreting the monoclonal antibody for amoxicillin. The recombinant ScFv antibody showed similar recognition ability for penicillins to its parental monoclonal antibody: simultaneous recognizing 11 penicillins with cross-reactivities of 18–107%. The three-dimensional structure of the ScFv antibody was simulated by using homology modeling, and its intermolecular interactions with 11 penicillins were studied by using molecular docking. Results showed that three CDRs are involved in antibody recognition; CDR L3 Arg 100, CDR H3 Tyr226, and CDR H3 Arg 228 were the key contact amino acid residues; hydrogen bonding was the main antibody–drug intermolecular force; and the core structure of penicillin drugs was the main antibody binding position. These results could explain the recognition mechanism of anti-amoxicillin antibody for amoxicillin and its analogs. This is the first study reporting the production of ScFv antibody for penicillins and stimulation studying its recognition mechanism.     

多管发酵法与其改进法检测水中粪大肠菌群的比较

粪大肠菌群是水体中粪便污染的重要指示菌，对于评价水质污染程度具有重要的卫生学意义。多管发酵法是传统的粪大肠菌群检测方法，但其步骤繁杂、周期长。目前，已有部分监测及科研人员对其进行了改进，笔者采用改进法与国标多管发酵法进行比较验证，认为Ec培养法可完全替代国标多管发酵法，纸片法亦可用于除酸性水样及菌量大的原污水外的其他环境水样中粪大肠菌群的检测。