中国环境治理:在“虎穴”与“狼窝”之间

<正>困境在对中国草原治理法律政策的研究中,内蒙古大学杨理教授对现行草原治理中的"围栏"思路进行了反思。他表达了这样一个迷惑:为什么我们刚刚逃离"公地的悲剧"虎口,又掉进了"围栏的陷阱"狼窝?如果一片草原是公共牧场,每个牧民都可以自由放牧,那么,他们每个个体的理性选择就是不停地增加     

西宁市城市植被生态系统服务功能价值研究

以西宁市为例,运用生态经济学原理和方法对城市植被生态系统服务功能进行评估,结果表明,2007年西宁市植被生态系统服务功能价值为2306．82×10^6元。西宁市不同类型植被生态系统的价值排序为：森林〉耕地〉草地〉园地,各项生态服务价值大小依次为：固碳释氧〉净化环境〉生物多样性保护〉调节气候〉涵养水源〉原材料生产〉保持土壤〉食物生产〉休闲娱乐,各植被类型生态服务价值的弹性系数都小于1,林地和园地的变化对生态服务价值变化起到放大作用。     

非质量氧同位素分馏效应研究进展

非质量氧同位素分馏效应(mass independent oxygenisotope fractionation)研究为一些重大地质科学问题的解释开辟了一条新途径。在简要介绍非质量分馏理论后,重点评述了非质量氧同位素分馏效应的研究进展,包括非质量同位素分馏效应的成因机制、氧同位素组成分析方法建立及其在环境地学领域的应用。并对非质量氧同位素分馏领域未来研究趋势作了进一步探讨。     

Greenhouse gas emissions from nitrogen fertilizer use in China

The use of synthetic nitrogen (N) fertilizers is an important driver of energy use and greenhouse gas (GHG) emissions in China. This paper develops a GHG emission factor for synthetic N fertilizer application in China. Using this emission factor, we estimate the scale of GHG emissions from synthetic nitrogen fertilizer use in Chinese agriculture and explore the potential for GHG emission reductions from efficiency improvements in N fertilizer production and use. The paper concludes with a discussion on costs and financing for a large-scale fertilizer efficiency improvement program in China, and how a GHG mitigation framework might contribute to program design.     

集成多种新技术提升广州水环境监测应急能力

多功能环境监测船是珠江流域第一艘集日常水环境监测、水环境应急监测和应急指挥功能于一体的专业监测船,具备水环境监测,环境污染应急指挥,污染事故处理和环保执法,以及珠江整治和科研考察等方面功能,为顺利开展环境应急监测、常规水体质量监测、环境保护执法以及珠江整治和科研考察提供安全、有效的科学工作平台,保证亚运会水体安全。     

碱渣废水的缓和湿式氧化处理分析

乙烯裂解过程中排放的碱渣废水,含有较高浓度的硫化物和有机物,本研究针对大庆石化总厂排放的乙烯裂解碱渣,采用缓和湿式氧化工艺,使处理后的废水硫化物小于2mg／L,并使COD去除率达到35％以上。     

萃取条件对支撑液膜法提取有机酸的影响

采用支撑液膜法分离提取混合液中的有机酸,通过萃取工艺条件优化,探讨支撑液膜法提取有机酸的可行性。由疏水微滤膜组件、载体、有机溶剂和反萃取剂组成的支撑液膜体系可以有效实现有机酸的分离提取。气相色谱分析表明,当提取时间为360min、给液相有机酸浓度为20g/L、载体体积浓度为10%及温度为30℃时,总有机酸提取率可达79.3%,较好实现了有机酸的同步提取和浓缩。     

基于Caco-2细胞单层模型的二硫化钨纳米材料肠毒性研究

二硫化钨纳米材料（WS₂）因其独特的晶体结构和机械柔韧性,在电子、能源和医药等领域应用前景广阔,但其毒性危害也受到广泛关注,本研究采用人结肠癌Caco-2细胞构建了体外肠道吸收模型,研究了WS₂纳米片对肠道细胞层结构和功能的毒性效应.结果表明,1~80 μg·mL^-1 WS₂未诱导Caco-2细胞内线粒体膜电位的改变,≥50 μg·mL^-1 WS₂增加了胞内氧化自由基含量,具有低细胞毒性.对于Caco-2细胞单层模型,2和20 μg·mL^-1 WS₂纳米片均不能改变其渗透性和完整性,未引起氧化应激相关基因表达的变化,但抑制了细胞膜ABC转运蛋白的活性.WS₂纳米片与镉、砷和苯并（a）芘等污染物共暴露于Caco-2细胞单层时,细胞膜损伤和细胞单层转运功能未被改变,但增加了镉对Caco-2细胞单层氧化应激相关基因GPx和OXSR1表达水平的影响.研究结果为WS₂纳米片的胃肠道毒性评估及健康风险评价提供了数据支撑.     

Fabrication and photocatalytic ability of an Au/TiO<Subscript>2</Subscript>/reduced graphene oxide nanocomposite

A new type of Au/TiO₂/reduced graphene oxide (RGO) nanocomposite was fabricated by the hydrothermal synthesis of TiO₂ on graphene oxide followed by the photodeposition of Au nanoparticles. Transmission electron microscopy images showed that Au nanoparticles were loaded onto the surface of both TiO₂ and RGO. Au/TiO₂/RGO had a better photocatalytic activity than Au/ TiO₂ for the degradation of phenol. Electrochemical measurements indicated that Au/TiO₂/RGO had an improved charge transfer capability. Meanwhile, chemiluminescent analysis and electron spin resonance spectroscopy revealed that Au/TiO₂/RGO displayed high production of hydrogen peroxide and hydroxyl radicals in the photocatalytic process. This high photocatalytic performance was achieved via the addition of RGO in Au/TiO₂/RGO, where RGO served not only as a catalyst support to provide more sites for the deposition of Au nanoparticles but also as a collector to accept electrons from TiO₂ to effectively reduce photogenerated charge recombination.

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Diversity and community composition of phosphorus accumulating organisms (PAOs) in the sediments of the Sanshiliujiao Lake reservoir北大核心CSCD

The diversity and community composition of phosphorus accumulating organisms (PAOs) in the sediments of the Sanshiliujiao Lake reservoir in Pingtan island, Fujian Province, were investigated by terminal restriction fragment length polymorphism (T-RFLP) methods combined with the construction of clone libraries. The diversity of PAOs in summer samples was significantly higher than that in winter. The dominant terminal restriction fragments (T-RFs) of PAOs were in the range of 200 to 300 bp in summer, while they were in the range of 150 to 200 bp in winter. Cloning sequencing and phylogenetic analysis showed that the main phyla of PAOs in the sediment of the Sanshiliujiao Lake reservoir were Proteobacteria, Actinobacteria, and Acidobacteria. Anaeromyxobacter, Azospirillum, Microlunatus phosphovorus, and Burkholderia were the dominant genera in the summer samples. Anaeromyxobacter, Methylobacterium, Solibacter, Azospirillum, and Microlunatus phosphovorus were the dominant genera in sediment samples in winter. The results of this study demonstrated that the diversity and community composition of PAOs in the sediments of the Sanshiliujiao Lake reservoir had specific seasonal characteristics. Various forms of phosphorus also showed their influence on the diversity of PAOs, especially Fe/Al-P. Our findings lays a scientific foundation for the future disclosure of microbial mechanisms involved in the phosphorus metabolic cycle in the sediments of reservoirs. © 2018 Science Press. All rights reserved.