Abundance and community of snow bacteria from three glaciers in the Tibetan Plateau

Bacterial abundance and diversity in snow of East Rongbuk,Laohugou and Hailuogou glaciers on the Tibetan Plateau were investigated through epifluorescence microscope and denaturing gradient gel electrophoresis.Cell abundance ranged from 4.0 × 10 3 to 290.2 × 10 3 cells/mL.The phylogenetic trees placed the 16S rRNA sequences in four major groups:Proteobacteria,Firmicutes,Actinobacteria and Bacteroidetes.Brevundimonas,Flavobacterium,Hymenobacter,Bacillus,Polaromonas,Rhodoferax and Streptomyces were widely distributed bacteria in glaciers from different cold regions.The remaining five genera of Hylemonella,Delftia,Zoogloea,Blastococcus and Rhodococcus were endemism,only recovered from our investigated glaciers.It is proposed that the three glaciers on the Tibetan Plateau provide a specific ecological niche for prolonging survival of diverse microbial lineages.     

中国水污染控制费用函数研究现状、问题与趋势

本研究对上个世纪八十年代起至今各个不同时期费用函数的研究内容、研究成果、研究目的进行全面梳理和分析,总结中国费用函数研究中六种费用函数模型,重点分析了费用-去除效率模型以及费用-规模、去除效率两种应用最为广泛的模型应用成果。在此基础上,分析中国费用函数研究中存在的五个方面主要问题。结合国家水专项项目费用函数研究目的,提出国家层面上开展费用函数研究的发展方向。     

Freshwater algae chemotaxonomy by high-performance liquid chromatographic (HPLC) analysis

The study of community composition of algae is essential for understanding the structure and dynamics of the aquatic ecosystem and for evaluating the eutrophic level of the water body. A high-performance liquid chromatographic (HPLC) method based on a reversephase C₁₈ nonpolar column was developed for the main algal taxa, which includes cyanophytes, bacillariophytes, euglenophytes, dinophytes, and chlorophytes. Based on the elution order using HPLC, 19 pigments were identified, and they were chlorophyllide a, 19′-butanoyloxyfucoxanthin, chlorophyll c ₁ + c ₂, phephorbides a, peridinin, methyl-chlorophyllide a, fucoxanthin, neoxanthin, violaxanthin, myxoxanthophyll, diadinoxanthin, diatoxanthin, lutein, zeaxanthin, chlorophyll b allomer, chlorophyll b, chlorophyll a allomer, chlorophyll a, and β,β-carotene. A comparison study of cell microscopic counts and accessory pigment analysis indicated that HPLC analysis could be a useful tool for monitoring phytoplankton communities and their abundance.     

内蒙古自治区实施排污权交易的探索

探索和建立排污权交易制度,实现稀缺环境资源的有偿使用,提高环境资源的配置效率,对于内蒙古自治区建立长效减排机制、改善环境质量有着非常现实的意义。本文在借鉴国内外排污权和碳交易理论和经验的基础上,分析内蒙古自治区排污权交易制度设计和实践特点,提出进一步完善和活跃内蒙古自治区排污权交易市场的对策建议。     

滨海化工区废水预处理去毒技术耦合工艺研究

化工产业是天津滨海新区重要的支柱产业,该行业废水是滨海污染物控制的主要威胁。针对常规单一方法存在的问题,试验选取滨海某化工区实际废水从内电解-Fenton、内电解-混凝、内电解-超声及微波强化氧化-光催化4种耦合去毒预处理工艺进行了研究。试验表明,与传统方法相比,内电解-Fenton法中H2O2的加入增加了污染物的降解途径,提高了对污染物的去除效率;内电解-混凝法对于制药废水的生物毒性有比较好的去除作用,不加PAM或Ca(OH)2的效果更佳;内电解-超声法对制药废水的生物毒性去除率可达92%,其可生化性提高45%;微波强化氧化-光催化法对大多数难降解物质有效,而对酚类物质降解效果不佳。     

The inactivation of bacteriophages MS2 and PhiX174 by nanoscale zero-valent iron: Resistance difference and mechanisms

• The resistance of phage PhiX174 to nZVI was much stronger than that of MS2. • The nZVI damaged the surface proteins of both bacteriophages. • The nZVI could destroy the nucleic acid of MS2, but not that of PhiX174. •The phage inactivation was mainly attributed to the damage of the nucleic acid. Pathogenic enteric viruses pose a significant risk to human health. Nanoscale zero-valent iron (nZVI), a novel material for environmental remediation, has been shown to be a promising tool for disinfection. However, the existing research has typically utilized MS2 or f2 bacteriophages to investigate the antimicrobial properties of nZVI, and the resistance difference between bacteriophages, which is important for the application of disinfection technologies, is not yet understood. Here, MS2 and PhiX174 containing RNA and DNA, respectively, were used as model viruses to investigate the resistances to nZVI. The bacteriophage inactivation mechanisms were also discussed using TEM images, protein, and nucleic acid analysis. The results showed that an initial concentration of 10⁶ PFU/mL of MS2 could be completely inactivated within 240 min by 40 mg/L nZVI at pH 7, whereas the complete inactivation of PhiX174 could not be achieved by extending the reaction time, increasing the nZVI dosage, or changing the dosing means. This indicates that the resistance of phage PhiX174 to nZVI was much stronger than that of MS2. TEM images indicated that the viral particle shape was distorted, and the capsid shell was ruptured by nZVI. The damage to viral surface proteins in both phages was examined by three-dimensional fluorescence spectrum and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). However, the nucleic acid analysis demonstrated that the nucleic acid of MS2, but not PhiX174, was destroyed. It indicated that bacteriophage inactivation was mainly attributed to the damage of nucleic acids.     

三唑酮对大型溞代际影响的转录组学分析

三唑酮是一种普遍使用的唑类杀菌剂,其对水生生物的危害已经引起广泛关注。为探讨三唑酮对无脊椎动物的毒性效应和致毒机理,以大型溞为模式生物,开展多代试验,评估不同浓度(5、12.5、25、50、100和200μg·L^(-1))的三唑酮对大型溞生长和繁殖以及每代时间间隔的影响。结果表明,暴露21 d后,200μg·L(-1))的三唑酮对大型溞生长和繁殖以及每代时间间隔的影响。结果表明,暴露21 d后,200μg·L^(-1)的三唑酮显著降低了大型溞的体长和繁殖能力。转录组分析发现,三唑酮暴露后,F1代和F2代的处理组与对照组的差异表达基因分别为376个和422个,而两代间的差异表达基因共2 604个。通过对差异表达基因的功能富集发现,三唑酮对大型溞F1代影响的主要通路有蛋白质吸收消化、视黄醇新陈代谢、氧化应激和甾类激素生物合成等,对F2代影响的主要通路有抗原处理和呈递、类固醇生物合成和谷胱甘肽代谢等。三唑酮对大型溞可能的毒性作用有氧化应激、内分泌干扰效应、神经毒性和免疫毒性,且可能会存在传代效应。     

压电智能骨料动态拉应力标定试验研究∗

为了监测混凝土内部受拉开裂损伤,提出了混凝土内部拉应力监测压电智能骨料,并对其进行了动态拉应力标定试验研究。首先,制备4个压电智能骨料受拉试件,建立拉应力监测系统;其次,对压电智能骨料施加往复拉应力,标定得到其灵敏度系数;然后,对压电智能骨料试件施加单调荷载直至其受拉破坏,得到其抗拉强度及输出的电压信号,对比了破坏过程的实际与监测荷载。结果表明,往复荷载作用下,SA输出与输入荷载呈良好的线性关系,SA的灵敏度系数一致性较好;单调荷载作用下,各SA抗拉强度均高于混凝土抗拉强度。综上,压电智能骨料有潜力应用于混凝土内部的拉应力监测。