Reproductive isolation between populations from Northern and Central Europe of the leaf beetle Chrysomela lapponica L.

Summary. Allopatric populations of the leaf beetle Chrysomela lapponica are known to feed upon either willow (Salicaceae) or birch (Betulaceae). This study aimed to elucidate the differentiation process of these allopatric populations. We investigated whether these allopatric populations specialized on different host plants are still able to produce fertile offspring when interbreeding. Individuals from a population in Finland (willow specialists) and one in the Czech Republic (birch specialists) were crossed in laboratory. Hybrid formation succeeded only between females from the Czech, birch specialized population and males from the Finnish, willow specialized population, while no eggs were produced by females of the willow specialists having mated males of the birch specialists. Behavioral, morphological, physiological, and chemical features of the F₁ hybrids were studied. The chemical composition of larval defensive secretion and feeding preferences of the resulting F₁ hybrids mainly showed similarities with the paternal phenotype, while the area of black coloring on the offspring’s elytra was intermediate between those of the parental elytra. F₁ hybrids did not accept the host plant (birch) of their mothers for feeding and only survived on willow. Thus, since mothers only lay eggs on birch, we found evidence for a postzygotic isolation mechanism between the individuals of the two investigated populations: when having been mated with willow specialized Finnish males, the birch specialized Czech mothers place the hybrid eggs on a plant species (birch), on which the hatching larvae cannot survive.     

土壤重金属污染现状与植物修复研究

概括了中国土壤重金属污染现状以及危害,总结了土壤重金属污染的植物修复类型和优缺点,超富集植物的研究进展重点阐述了植物对土壤重金属耐性和富集机制,以及超富集植物的种质资源,最后指出了植物修复未来的研究趋势。     

新时期环境执法和环境监测联动机制构建探索

如何使环境执法与环境监测有机融合、协同联动,促进环境管理工作高效开展,是现阶段生态环境部门急需解决的问题。通过分析环境执法与环境监测在实际工作中存在的问题及新时期环境执法和环境监测融合发展的意义,提出应积极构建二者协同联动机制,以解决新型生态环境问题。     

Adsorption mechanisms of PFOA onto activated carbon anchored with quaternary ammonium/epoxide-forming compounds: A combination of experiment and model studies

When wood-based activated carbon was tailored with quaternary ammonium/epoxide (QAE) forming compounds (QAE-AC), this tailoring dramatically improved the carbon's effectiveness for removing perfluorooctanoic acid (PFOA) from groundwater. With favorable tailoring, QAE-AC removed PFOA from groundwater for 118,000 bed volumes before half-breakthrough in rapid small scale column tests, while the influent PFOA concentration was 200 ng/L. The tailoring involved pre-dosing QAE at an array of proportions onto this carbon, and then monitoring bed life for PFOA removal. When pre-dosing with 1 mL QAE, this PFOA bed life reached an interim peak, whereas bed life was less following 3 mL QAE pre-dosing, then PFOA bed life exhibited a steady rise for yet subsequently higher QAE pre-dosing levels. Large-scale atomistic modelling was used herein to provide new insight into the mechanism of PFOA removal by QAE-AC. Based on experimental results and modelling, the authors perceived that the QAE's epoxide functionalities cross-linked with phenolics that were present along the activated carbon's graphene edge sites, in a manner that created mesopores within macroporous regions or created micropores within mesopores regions. Also, the QAE could react with hydroxyls outside of these pore, including the hydroxyls of both graphene edge sites and other QAE molecules. This latter reaction formed new pore-like structures that were external to the activated carbon grains. Adsorption of PFOA could occur via either charge balance between negatively charged PFOA with positively charged QAE, or by van der Waals forces between PFOA's fluoro-carbon tail and the graphene or QAE carbon surfaces.     

强电离放电脱除NO的化学反应动力学模拟

强电离放电脱除NO是集化学、物理学和环境工程学为一体的交叉学科,其脱除过程本质上是等离子体中进行的一系列微观过程,难以通过实验进行直接研究。故通过建立强电离放电脱除模拟烟气中NO的化学模型并运用MATLAB对其进行数值模拟以探讨NO的去除机理。数值模拟结果表明,在800 μs内产生大量·O和·OH,而仅产生少量·N,由此可知NO的去除主要是通过与·O和·OH的氧化反应生成HNO3实现的,在脱除过程中NO先被氧化成NO2,再进一步被转化成HNO3。同时,通过实验验证了所建立模型的合理性。实验结果表明：随着NO初始浓度的增加,NO脱除效率逐渐下降;随着含氧量的增加,NO脱除效率显著增大。     

厦门海域防控陆源污染的实践与经验

在分析厦门海域主要污染物来源的基础上,总结了厦门市针对不同来源的水污染物开展的治理措施,并重点介绍了厦门市关于化工废水、电镀废水、生活污水和养殖废水的处理与利用的4个典型实例.厦门市在防治陆源污染的实践中,逐渐形成并发挥重要作用的5项机制,即管理机制、组织协调机制、法规保障机制、科技进步机制、经济激励机制.     

Detection of fetal cells in maternal blood

We report the detection of fetal cells in the maternal circulation by enzymatic amplification of a single copy gene sequence that was fetal-specific. Fetal HLA-A2-positive cells were sorted from maternal HLA-A2-negative cells by flow cytometry and confirmed by demonstration of a fetal-specific HLA-DR4 sequence. However, this sequence could not be detected in unenriched maternal DNA prepared at 28 and 32 weeks' gestation. The sensitivity of detection was 1 HLA-DR4-positive cell in 10⁵ HLA-DR4-negative cells. We conclude that prenatal diagnosis of paternally inherited autosomal-dominant genetic defects may be possible by selective gene amplification of maternal peripheral blood. However, preliminary enrichment for fetal cells may be necessary.     

北京土地利用/覆盖变化机制研究

利用７０年代、８０年代和９０年代（ＳＰＯＴ）３个时段北京市土地利用资料进行土地利用／覆盖研究,分析其变化机制。北京土地利用变化的形式主要以轴向扩展、卫星城建设、工厂郊迁、郊区大型中价商城建设、郊外别墅区等为主,土地覆盖变化的主要形式有：①内城更新与改造;②商贸街的重建;③粗放型用地向集约型用地的转变。     

Cationic content effects of biodegradable amphoteric chitosan-based flocculants on the flocculation properties

A series of biodegradable amphoteric chitosan-based flocculants (3-chloro-2-hydroxypropyl trimethyl ammonium chloride (CTA) modified carboxymethyl chitosan, denoted as CMC-CTA) with different substitution degrees of CTA were prepared successfully. The content of carboxymethyl groups in each CMC-CTA sample was kept almost constant. The solubility of the various flocculants showed that, higher cationic content of flocculants caused a better solubility. The flocculation experiments using kaolin suspension as synthetic water at the laboratory scale indicated that the substitution degree of CTA was one of the key factors for the flocculation properties. With the increase of cationic content, the flocculants were demonstrated better flocculation performance and lower dosage requirement. Flocculation kinetics model of particles collisions combining zeta potential and turbidity measurements was employed to investigate the effects of the cationic content of the flocculants on the flocculation properties from the viewpoint of flocculation mechanism in detail. Furthermore, flocculation performance using raw water from Zhenjiang part of Yangtze River at the pilot scale showed the similar effects to those at the laboratory scale.     

锦标机制理论下企业低碳经济发展激励机制研究

按照企业发展与环境相容的原则,低碳经济是应对全球变暖的最佳经济模式,低碳经济以低能耗、低排放、低污染为基本特征,以应对碳基能源对于气候变暖影响为基本要求,以实现经济社会的可持续发展为基本目的.鉴于当前文献关于企业发展低碳经济的激励机制研究还略显不足,文章借鉴激励理论中的委托代理理论,根据Malcomson模型的研究方法,构建了包括1阶段合约和2阶段合约的企业发展低碳经济的激励机制框架,设立基于相对业绩的"锦标机制"模型并对模型进行系统分析,推导出政府在制定企业发展低碳经济激励政策时的注意事项,即中央政府要加大财政转移支付力度,支持地方发展低碳经济;地方政府要设立专门的低碳经济发展激励基金,并纳入财政预算管理;地方政府在激励企业发展低碳经济时,要有层次、有针对的对企业给予政策支持或财政补贴,形成阶梯式的支持结构,使有限财政资金得到合理配置;地方政府应该以区域内企业实施低碳经济活动的努力水平为评判标准对企业进行激励.