我国4种重要海水经济鱼类热忍受研究

为了探明我国重要海水经济鱼类的热忍受能力,分别采用急性升温和缓慢升温两种方法对大黄鱼Pseudosciaena crocea、鲈鱼Lateolabrax joponicus、真鲷Pagrosomus major、黑鲷Sparus macrocephalus进行了室内热效应模拟实验.研究结果表明:在夏季自然起始水温为28.5℃条件下,大黄鱼,鲈鱼和黑鲷的急性升温半致死温度(LT50)分别为34.2,33.9和36.4℃;大黄鱼,鲈鱼,真鲷和黑鲷的临界热最大值(critical thermal maxima,CTmax)分别为35.0,34.7,32.7和36.8℃.     

最小二乘支持向量机在臭氧浓度时间序列预测中试应用

将基于统计学理论的最小二乘支持向量机(LSSVM)方法试用于臭氧浓度时间序列预测.首先利用臭氧浓度时间序列资料重构了该混沌动力系统的相空间,然后沿着系统演化的相轨道用最小二乘支持向量机建立了臭氧浓度短时预测模型,并用上海市淀山湖站的臭氧观测资料做了提前1～8 h和提前24 h预报试验,结果显示这一模式能够较好地模拟臭氧浓度演化轨迹,提前1～8 h的预测精度均超过90%,提前24 h预报精度亦都在68%以上,预报效果较好.     

Impacts of atmospheric pollution on the plant communities of British acid grasslands

Air pollutants are recognised as important agents of ecosystem change but few studies consider the effects of multiple pollutants and their interactions. Here we use ordination, constrained cluster analysis and indicator value analyses to identify potential environmental controls on species composition, ecological groupings and indicator species in a gradient study of UK acid grasslands. The community composition of these grasslands is related to climate, grazing, ozone exposure and nitrogen deposition, with evidence for an interaction between the ecological impacts of base cation and nitrogen deposition. Ozone is a key agent in species compositional change but is not associated with a reduction in species richness or diversity indices, showing the subtly different drivers on these two aspects of ecosystem degradation. Our results demonstrate the effects of multiple interacting pollutants, which may collectively have a greater impact than any individual agent.     

Removal of Alachlor from Water by Catalyzed Ozonation in the Presence of Fe2+, Mn2+, and Humic Substances

Abstract

The effects of Fe(II), Mn(II) and humic substances on the catalyzed ozonation of alachlor, an endocrine disruptor were investigated. Results revealed that small amounts of Fe(II), Mn(II), and humic substances could enhance the ozonation of alachlor, but larger amounts of them would retard the oxidation. These results were successfully identified by an electron paramagnetic resonance (EPR) spectroscopy/spin-trapping method that could quantify hydroxyl radicals. The production of hydroxyl radicals was obviously increased with the increasing of Fe(II) concentration, which contributed to enhance ozonation at low concentrations. But the excess Fe(II) consumed some of the radicals when it was added at a higher concentration (1.5 mg/L). However, no obvious radicals were observed when a different amount of Mn(II) was used, and the catalytic ozonation of alachlor by Mn(II) mainly followed the mechanism of “active sites created on the surface of MnO₂.” The radical pathway was followed when alachlor was ozonated with different concentrations of humic substances because of its radical initiating, promoting, and inhibiting effects.     

臭氧发生器应用技术现状

概述了臭氧在环境保护中的重要作用，介绍了臭氧发生器应用现状及其处理技术的进展，强调了高效臭氧发生器在废水处理中的现实意义。     

被动扩散技术在环境空气监测中的应用

被动扩散监测技术以其成本低、布点灵活、操作简单，易于掌握等特点在世界各地广泛应用于环境空气质量监测。辽宁省环保局通过欧盟项目引入，盘锦市试点表明SO2和NO2各月变化趋势和各功能区监测结果与我市自动站监测结果相一致。可以弥补自动监测点位不足和开展大范围多点位监测。     

The Role of Fungal Symbioses in the Adaptation of Plants to High Stress Environments

All plants studied in natural ecosystemsare symbiotic with fungi that either resideentirely (endophytes) or partially(mycorrhizae) within plants. Thesesymbioses appear to adapt to biotic andabiotic stresses and may be responsible forthe survival of both plant hosts and fungalsymbionts in high stress habitats. Here wedescribe the role of symbiotic fungi inplant stress tolerance and present astrategy based on adaptive symbiosis topotentially mitigate the impacts of globalchange on plant communities.     

Impacts of pollution heterogeneity on population exposure in dense urban areas using ultra-fine resolution air quality data

Traditional air quality data have a spatial resolution of 1 km or above, making it challenging to resolve detailed air pollution exposure in complex urban areas. Combining urban morphology, dynamic traffic emission, regional and local meteorology, physicochemical transformations in air quality models using big data fusion technology, an ultra-fine resolution modeling system was developed to provide air quality data down to street level. Based on one-year ultra-fine resolution data, this study investigated the effects of pollution heterogeneity on the individual and population exposure to particulate matter (PM_2.5 and PM₁₀), nitrogen dioxide (NO₂), and ozone (O₃) in Hong Kong, one of the most densely populated and urbanized cities. Sharp fine-scale variabilities in air pollution were revealed within individual city blocks. Using traditional 1 km average to represent individual exposure resulted in a positively skewed deviation of up to 200% for high-end exposure individuals. Citizens were disproportionally affected by air pollution, with annual pollutant concentrations varied by factors of 2 to 5 among 452 District Council Constituency Areas (DCCAs) in Hong Kong, indicating great environmental inequities among the population. Unfavorable city planning resulted in a positive spatial coincidence between pollution and population, which increased public exposure to air pollutants by as large as 46% among districts in Hong Kong. Our results highlight the importance of ultra-fine pollutant data in quantifying the heterogeneity in pollution exposure in the dense urban area and the critical role of smart urban planning in reducing exposure inequities.     

Formation control of bromate and trihalomethanes during ozonation of bromide-containing water with chemical addition: Hydrogen peroxide or ammonia?

To ensure the safety of drinking water, ozone (O₃) has been extensively applied in drinking water treatment plants to further remove natural organic matter (NOM). However, the surface water and groundwater near the coastal areas often contain high concentrations of bromide ion (Br^?). Considering the risk of bromate (BrO₃^?) formation in ozonation of the sand-filtered water, the inhibitory efficiencies of hydrogen peroxide (H₂O₂) and ammonia (NH₃) on BrO₃^? formation during ozonation process were compared. The addition of H₂O₂ effectively inhibited BrO₃^? formation at an initial Br^? concentration amended to 350 µg/L. The inhibition efficiencies reached 59.6 and 100% when the mass ratio of H₂O₂/O₃ was 0.25 and > 0.5, respectively. The UV₂₅₄ and total organic carbon (TOC) also decreased after adding H₂O₂, while the formation potential of trihalomethanes (THMsFP) increased especially in subsequent chlorination process at a low dose of H₂O₂. To control the formation of both BrO₃^? and THMs, a relatively large dose of O₃ and a high ratio of H₂O₂/O₃were generally needed. NH₃ addition inhibited BrO₃^? formation when the background ammonia nitrogen (NH₃N) concentration was low. There was no significant correlation between BrO₃^? inhibition efficiency and NH₃ dose, and a small amount of NH₃N (0.2 mg/L) could obviously inhibit BrO₃^? formation. The oxidation of NOM seemed unaffected by NH₃ addition, and the structure of NOM reflected by synchronous fluorescence (SF) scanning remained almost unchanged before and after adding NH₃. Considering the formation of BrO₃^? and THMs, the optimal dose of NH₃ was suggested to be 0.5 mg/L.     

截流法研究CS2和O3的反应

应用截流法研究了气相CS_2和O_3的反应。研究表明,CS_2和O_3的反应为表观二级反应,在干燥氮气和干燥空气条件下得到反应速率常数k_Ⅱ分别为5.47、5.28 L/(mol·s)。水汽明显加快反应速率。Co_3Ccs_2时,反应最终产物为CO_2、COS和SO_2。并讨论了反应机理。