介质阻挡放电联合催化臭氧化降解甲苯

采用介质阻挡放电区后结合MnOx/Al2O3/发泡镍去除甲苯,考察甲苯进气方式、臭氧产生方法及湿度对甲苯与O3同时去除的影响。结果表明,O3是等离子体区后催化降解甲苯的主要物种,介质阻挡放电联合催化臭氧化可实现甲苯及O3的同时高效去除。输入电压为9.0 kV时,甲苯的去除效率达92.8%,在80 min内O3的去除效率维持在99%以上。水蒸气对催化剂催化分解臭氧的活性没有直接的影响,O3浓度较高时湿度对甲苯降解效率的影响很小。GC-MS分析结果表明,甲苯降解的主要气相副产物有烷烃、酸、酮和含苯环有机物,提出了甲苯的降解途径。     

云南兰花生物技术的商品化开发

云南是我国兰科植物资源最丰富的地区，云南兰花共１００属４７２种，中国传统的观赏兰花－兰属植物和具开发潜力的热带兰种类多、分布广，使云南成为天然的兰花资源基因 。近年来，采挖性的商品开发导致云南丰富的兰花资源遭到严重破坏。     

九峰山地区的生物资源及其保护

九峰山地区天然植被保存完整,动植物资源颇为丰富。该区有维管束植物82科302属596种;陆栖脊椎动物134种,其中兽类25种、鸟类100种(另有2亚种)、两栖和爬行类7种、鱼类2种。蒙古扁桃和黄芪为国家三类保护植物,青羊和雪豹为国家二类保护兽类,金雕等13种鸟为国家二类保护鸟类;另外还有其它用途的经济动、植物。     

论湘中城市群经济的融合耦动与可持续发展

本文以湘中（长株潭）城市群作为研究对象,概述了湘中城市群经济融合的总体特征,对其城市群空间生长演化过程中存在的问题和应采取的对策,经济如何实现可持续发展进行了探讨。     

流动注射分光光度法测定水中铝的含量

以桑色素作显色剂，采用流动注射分光光度法测定水中铝的含量。在桑色素质量浓度为0．8g／L、聚氧乙烯辛基苯基醚体积分数为1．0％、进样环体积为400μL、检测波长420nm的条件下，采用流动注射分光光度法对水中铝的含量进行测定，本方法的线性范围为2～300μg／L，检出限（信噪比为3）为0．124μg／L，相对标准偏差为2．9％，加标回收率为96．4％～101．8％。     

Fe^0-厌氧微生物体系处理活性艳红X-3B的试验研究

采用间歇式摇床试验，研究了葡萄糖共基质条件下Fe^0-厌氧微生物体系中Fe^0投加量、pH值、染料初始浓度对活性艳红X-3B模拟废水脱色率的影响，比较了Fe^0-厌氧微生物、纯厌氧微生物及纯Fe^0 3种体系中废水的脱色效果。结果表明：Fe^0-厌氧微生物体系中初始浓度（50～500mg／L）对活性艳红X-3B的脱色率影响不大；而Fe^0投加量、pH值存在一个最佳范围；当Fe^0投加量为260mg／L，pH值为6．0，污泥浓度为0．35gVSS／L，停留时间约为30h时，体系中活性艳红X-3B的脱色率可达90％左右，比相同试验条件下纯Fe^0、纯厌氧微生物体系达到此脱色率所需时间分别缩短了约1／2、7／10。在Fe^0-厌氧微生物体系中，由紫外可见分光光度分析可推测活性艳红X-3B的脱色机理主要是其偶氮键发生断裂，生成苯胺和萘类物质，而且苯胺和萘类物质能得到进一步降解。     

Accumulation and quantitative estimates of airborne lead for a wild plant (Aster subulatus)

Foliar uptake of airborne lead is one of the pathways for Pb accumulation in plant organs. However, the approximate contributions of airborne Pb to plant organs are still unclear. In the present study, aerosols (nine-stage size-segregated aerosols and total suspended particulates), a wild plant species (Aster subulatus) and the corresponding soils were collected and Pb contents and isotopic ratios in these samples were analyzed. Average concentration of Pb was 96.5 ± 63.5 ng m⁻³ in total suspended particulates (TSP) and 20.4 ± 5.5 ng m⁻³ in the fine fractions of size-segregated aerosols (SSA) (<2.1 μm), higher than that in the coarser fractions (>2.1 μm) (6.38 ± 3.71 ng m⁻³). Enrichment factors show that aerosols and soils suffered from anthropogenic inputs and the fine fractions of the size-segregated aerosols enriched more Pb than the coarse fractions. The order of Pb contents in A. subulatus was roots > leaves > stems. The linear relationship of Pb isotope ratios (²⁰⁶Pb/²⁰⁷Pb and ²⁰⁸Pb/²⁰⁶Pb) among soil, plant and aerosol samples were found. Based on the simple binary Pb isotopic model using the mean ²⁰⁶Pb/²⁰⁷Pb ratios in TSP and in SSA, the approximate contributions of airborne Pb into plant leaves were 72.2% and 65.1%, respectively, suggesting that airborne Pb is the most important source for the Pb accumulation in leaves. So the combination of Pb isotope tracing and the simple binary Pb isotope model can assess the contribution of airborne Pb into plant leaves and may be of interest for risk assessment of the exposure to airborne Pb contamination.     

The fungicide difenoconazole alters mRNA expression levels of human CYP3A4 in HepG2 cells

The fungicide difenoconazole has been frequently detected in agricultural products, soils and surface waters, causing increasingly public concern due to toxicological properties. Although systemic triazole fungicides can inhibit the enzymatic activity of many CYP450 isozymes, how difenoconazole affects the human CYP3A4 still remains largely unknown. We thus investigated the effect of difenoconazole on normal mRNA expression and protein expression of human CYP3A4 by real-time quantitative PCR and western blot, respectively. Results show that the exposure to difenoconazole from 0.01 to 0.5 μM for 24 h down-regulates mRNA expression levels of human CYP3A4 in HepG2 cells. We also found that difenoconazole could inhibit the enzymatic activity of human CYP3A4 in a concentration-dependent mode. The IC₅₀ of difenoconazole for inhibition of CYP3A4 activity is 0.41 µM, showing a stronger inhibitor in comparison with ketoconazole. Overall, our findings indicate the potential risk of difenoconazole for the disruption of human CYP3A4.     

Growth responses of the newly-discovered Cd-hyperaccumulator Rorippa globosa and its accumulation characteristics of Cd and As under joint stress of Cd and As

Rorippa globosa has been identified as a newly-found Cd-hyperaccumulating species. In the present study, growth responses of Rorippa globosa and its accumulation characteristics of Cd and As were examined under joint stress of Cd and As. The results showed that Cd and As had an antagonistic effect on enhancing the growth of Rorippa globosa plants and Cd uptake and accumulation under the low concentration Cd and As treatments. When the concentration of Cd in the soil was 10 mg/kg and the concentration of As was 50 mg/kg, the highest growing height of the plant was up to 35.9 cm and the dry weight of the shoots was up to 2.2 g/pot, respectively. Meanwhile, the accumulation of Cd in the leaves under the joint stress was higher than that at the same level under single Cd pollution. However, there were synergic adverse effects on plant growth and Cd uptake under the combined pollution from a high concentration of Cd and As. Meanwhile, the accumulation of As in the roots was greater than that in the shoots, the translocation factor (TF) was ?0.3 and the bioaccumulation factor (BF) was ?0.6, thus showing that Rorippa globosa had an excluding effect on As uptake. These results confirmed that Rorippa globosa had a strong tolerant ability to the joint stress of Cd and As, and the potential for phytoremediation of soils contaminated by Cd and As.     

水污染突发事件：演化模型与应急管理

概述了突发事件演化研究的现状，总结了现阶段中国水污染突发事件的典型案例，研究了事件的演化过程，提出把社会因素和全过程干预作为水污染突发事件演化动因的一个重要方面，并在此基础上分析了水污染突发事件演化的主要动力因素，运用灾害学、应急管理、环境科学等相关理论构建了事件演化的动力因素体系，最后从系统分析的角度构建了水污染突发事件演化模型。研究表明：社会因素和应急干预对水污染突发事件的演化具有推动作用；事件演化具有阶段性，不同阶段的动力因素存在差异；水污染突发事件应急管理具有多目标性，单一目标应急管理不能有效控制水污染突发事件演化。研究水污染突发事件演化机理可为政府有效地预警与事件初期的应急决策提供重要的理论依据。