江西省环境与经济耦合关系研究

根据江西省环境与经济的发展状况,综合运用熵值法和线性加权法对区域环境与经济发展水平作出评价,并利用协同论和容量耦合概念建立两种数学模型对江西省环境与经济耦合关系进行研究.结果表明:江西省经济实力在不断增强,环境质量先快速下降后略微上升,环境与经济的耦合关系在不断增强,15年内一直处于协调发展水平,且发展水平在不断提高.对比分析两种模型,发现两模型用于评价区域环境与经济耦合关系均具有一定的科学性和合理性,但基于协同论的协调度和协调发展度模型更能反映江西省环境与经济的耦合关系.     

沈阳市国三和国四排放标准不同车型柴油车PM2.5和PM10排放因子及碳组分源谱

柴油车是机动车排放的大气颗粒物的主要来源,为研究沈阳市柴油车PM_(2.5)和PM_(10)的排放因子及其碳组分排放特征,采用检车线车载测试方法采集了15辆国三和国四排放标准的小型、中型、大型载客和轻型、中型、重型载货柴油车尾气样品,并对其中的碳组分进行化学分析.结果表明,国三柴油车PM_(2.5)和PM_(10)的排放因子分别为(0. 193±0. 092) g·km-1和(0. 338±0. 305) g·km-1,国四柴油车PM_(2.5)和PM_(10)的排放因子分别为(0. 085±0. 038) g·km-1和(0. 100±0. 042) g·km-1,随排放标准的提升PM_(2.5)和PM_(10)排放因子显著下降.同一排放标准下,排放因子随车型的增大而增大. TC为柴油车的主要组分,国四柴油车中TC的质量分数(23%～48%)明显低于国三柴油车(29%～70%).各车型柴油车元素碳(EC)的质量分数均大于有机碳(OC),OC/EC为0. 70±0. 29,且国四柴油车OC/EC值低于国三柴油车.因载客汽车总行驶里程明显高于载货汽车导致油耗较高,相同排放标准载客汽车OC和EC的质量分数高于载货汽车.国三、国四柴油车质量分数最高的碳组分均为EC2,可将EC2作为柴油车的标识组分.     

基于模糊综合评价法的乐清湾湿地生态安全评价

基于湿地生态安全的相关理论,以2007年的Landsat TM遥感影像为基础,结合实地调查数据,采用模糊综合评价法和熵值赋权法,从结构功能、可持续利用能力和动态变化3方面着手,构建了湿地生态安全评价指标体系,探讨了一种定性与定量相结合的湿地生态安全评价方法,并对温州乐清湾湿地进行了评价。结果表明乐清湾湿地生态系统在整体上属于亚健康状态,分析其原因,主要表现在人口增长快、大面积围垦湿地、地质灾害频发及环境污染等方面。该项研究可为湿地资源的开发规划与管理提供参考。     

Influence of pesticides on activities of invertase,amylase and level of adenosine triphosphate in organic soil

Laboratory tests showed that none of the pesticide treatments inhibited invertase and amylase activities. With the exception of nitrapyrin at the low level, all treatments inhibited ATP in the soil for 1 day and then showed a rapid recovery.     

Effects of pesticides on activities of enzymes and microorganisms in a clay soil

Laboratory experiments were conducted to determine the effect of 32 pesticides applied at 2 levels on populations of microorganisms, activities of urease, dehydrogenase, phosphatase and nitrogenase in a clay loam incubated for 1 week. Results indicated that a decrease in bacterial number was observed with thiram for 2 days and stimulation with chlorpyrifos after 7 days. Some fungicides and fumigants inhibited fungal numbers for 2 days. The recovery was rapid and stimulatory effects on microbial numbers were evident in many samples. None of the pesticides inhibited soil urease drastically. Formazan formation was not suppressed vigorously by the treatments. With the exception of DD and Vorlex at a high level, none of the treatments inhibited phosphatase in the hydrolysis of p-nitrophenyl disodium orthophosphate. A temporary decrease in nitrogenase activity in acetylene (C2H2) reduction was observed with many pesticides. The low amount of pesticides applied to the clay loam is unlikely to have detrimental effects on soil microbes and the enzymes important to soil fertility.     

Efficient microwave-assisted photocatalytic degradation of endocrine disruptor dimethyl phthalate over composite catalyst ZrOx/ZnO

A highly active ZrOx/ZnO catalyst for microwave-assisted photocatalytic (MW/PC) degradation of endocrine disruptor dimethyl phthalate (DMP) has been prepared via cetyltrimethylammonium assisted hydrothermal method. The ZrOx/ZnO was characterized by XPS, XRD, UV-Vis, BET and SEM techniques. The XPS result showed that Zr oxides with different valences (+2, +3, +4) co-existed in ZrOx/ZnO. By using the ZrOx/ZnO (0.1 g), the TOC removal efficiency of DMP (100 mL of 50 mg/L) was 88% after 30 min reaction, which was about 15% higher than P25 TiO2. It was found that the removal process of DMP by MW/PC followed pseudo first-order kinetics in all cases, and ZrOx/ZnO significantly accelerated the degradation of DMP. The degradation half-life time of DMP was shortened 45% compared with P25 TiO2. A possible catalytic mechanism was proposed based on microwave response and interfacial charge transfer. ZrOx/ZnO could be reused for six times without obvious decrease in catalytic activity. The study offers new insights into designing highly efficient catalysts for MW/PC process and is applicable for MW/PC environmental remediation.     

额济纳天然胡杨林水分利用效率动态变化研究

黑河下游的额济纳绿洲是我国西北地区重要的生态屏障,也是当地人民赖以生存的自然资源,然而由于种种原因,这片绿洲正在衰败并且有消亡的危险.胡杨是典型的潜水旱中生植物,它虽然有较强的耐大气干旱、耐盐碱能力,其生长发育与水分条件的优劣有着十分密切的关系.本文通过研究额济纳天然胡杨的叶水势、蒸腾速率、光合速率的变化规律,综合分析其水分利用效率与叶水势的相关关系,了解胡杨树体内水分运移关系,为揭示胡杨生存现状和合理利用水资源提供理论依据,为合理保护额济纳绿洲胡杨林提供科学支持.     

Enantioselective separation and zebrafish embryo toxicity of insecticide beta-cypermethrin

Enantioselectivity of chiral pollutants is receiving growing concern due to the difference in toxicology and environment fate between enantiomers.In this study,enantiomers of insecticide beta-cypermethrin (beta-CP) were separated on selected chiral column by HPLC,and the toxicity of enantiomers was evaluated using the zebrafish embryo-larval assays.The enantiomers of beta-CP were baseline separated on Chiralcel OD and Chiralpak AD columns and detected by circular dichroism (CD) at 236 nm.Better separation could be achieved at lower temperature (e.g.,20°C) and with lower levels of polar modifiers.Pure enantiomers were obtained on Chiralcel OD.The CD spectra of enantiomers were recorded.By comparing the elution order with a previous similar study,the absolute configuration of beta-CP enantiomers was determined.The individual enantiomers were used in zebrafish embryo test,and the results showed that beta-CP enantioselectively induced yolk sac edema,pericardial edema and crooked body.The 1R-cis-αS and 1R-trans-αS enantiomers showed strong developmental toxicities at concentration of 0.1 mg/L,while the 1S-cis-αR and 1S-trans-αR induced no malformations at higher concentration (e.g.,0.3 mg/L).The results suggest that the enantioselective toxicological effects of beta-CP should be considered when evaluating its ecotoxicological effects.     

石生苔藓碳含量和碳同位素对城市地区人为二氧化碳和大气氮沉降变化的响应

对贵阳市区到农村地区4个方向的石生苔藓碳氮含量和同位素组成进行了分析.苔藓碳含量（34.47%～52.76%）从市区到农村随距离逐渐降低,并与氮含量（0.85%～2.97%）存在较好的正相关关系,表明大气氮沉降对苔藓的碳吸收能力具有促进作用,市区较高的大气氮输入或铵沉降增强了苔藓的光合作用和固碳能力,同时使碳同化过程发生较大的¹³C分馏.苔藓δ¹³C值（-30.69‰～-26.96‰）从市区往外逐渐升高,还与城市人为CO₂排放有关,主要机制在于人为成因的CO₂源本身富含¹²C并可能增加市区大气CO₂的浓度,从而导致市区苔藓δ¹³C值偏负.此外,根据苔藓碳含量和δ¹³C随距离的变化关系判断,贵阳城市人为来源的CO₂对植物的影响主要集中在20 km范围内.本研究重点探讨了控制苔藓碳含量和δ¹³C变化的因素及其与氮素的相互关系,揭示了苔藓碳和δ¹³C响应城市CO₂排放和大气氮沉降变化的规律,为城市大气污染的防治和周边生态系统的保护提供了新的地球化学证据.