2015年冬季苏州城市热岛特征研究

基于Landsat土地利用类型分类资料、夜间灯光影像资料、自动气象站资料以及大气边界层探测资料,划分出城市、郊区以及湖区代表站,分析了苏州2015年1月城市热岛日变化、昼夜差异特征以及城、湖温度差日变化特征,并对苏州城市热岛分布特征以及城、湖大气边界层结构差异进行分析。结果显示：(1)白天热岛强度小,09~17时热岛强度均小于1℃,最小值仅为02℃;夜间热岛强度大,19~05时热岛强度维持在12℃以上,最大值为17℃。(2)城、湖温差白天为正,夜间为负,市区变温速率比湖区快约02℃/h。(3) 苏州白天热中心形状不规则,范围大,城郊温差小,夜间形成单一封闭稳定热中心,热中心形状与市区有较好对应,城、郊温差维持在15℃左右。冬季地面盛行西北风,太湖湖陆风现象显著,湖陆风和盛行风向共同影响城市热羽向西南方向发展。（4）城、湖虚位温廓线在白天差异小,均有不稳定边界层形成,夜间市区仍维持不稳定边界层,而湖区有稳定边界层发展,近地层内干岛效应显著。(5)城市热岛影响范围有明显日变化特征,白天城市热岛影响范围小于40 m,夜间大于200 m。     

Land cover effects on water balance partitioning in the Colombian Andes: improved water availability in early stages of natural vegetation recovery

Regional Environmental Change - Vegetation actively affects different components of the water budget in multiple spatial and temporal scales. Changes in vegetation cover and structure—such as...     

Shared environment,diversity of pathways: dynamics of family farming in the Saïs Plain (Morocco)

Regional Environmental Change - The sustainability of family farming and its capacity to respond to global changes are widely debated. Based on a survey of 40 farms on the Saïs Plain in...     

The evolving local social contract for managing climate and disaster risk in Vietnam

How do disasters shape local government legitimacy in relation to managing climate‐ and disaster‐related risks? This paper looks at how local authorities in Central Vietnam perceive their social contract for risk reduction, including the partial merging of responsibilities for disaster risk management with new plans for and investments in climate change adaptation and broader socioeconomic development. The findings indicate that extreme floods and storms constitute critical junctures that stimulate genuine institutional change. Local officials are proud of their strengthened role in disaster response and they are eager to boost investment in infrastructure. They have struggled to reinforce their legitimacy among their constituents, but given the shifting roles of the state, private sector, and civil society, and the undiminished emphasis on high‐risk development models, their responsibilities for responding to emerging climate change scenarios are increasingly nebulous. The past basis for legitimacy is no longer valid, but tomorrow's social contract is not yet defined.     

Occurrence and human dietary assessment of sulfonamide antibiotics in cultured fish around Tai Lake,China

As the most important fishery medicines, sulfonamides are widely used to prevent diseases caused by pathogens in aquaculture. However, relatively little is known about the residues and dietary risks associated with cultured fish around Tai Lake. In the present study, a sampling strategy for a complete aquaculture period was conducted. Specifically, 12 selected sulfonamide antibiotics were measured among 116 fish samples recruited from four sampling periods, four species, four areas, and 18 fish ponds. All 12 antibiotics were detected at detection frequencies of 4.31–28.45%. Total sulfonamides were detected in 77.59% of the fish samples, with 57.76% of fish samples containing from 0.1 to 10 μg kg^?1. Sulfadiazine (SDZ), sulfamethoxazole (SMZ), sulfamethazine (SDD), and sulfamonomethoxine (SMM) were the main types of antibiotics used, and these were present at high concentrations (>100 μg kg^?1) with high occurrences, especially in the middle of the aquaculture season. Dietary assessment showed that residual antibiotics in all fish that were being sent to market were far below the maximum residue limit (MRL) of total sulfonamides and that there was almost no risk associated with fish consumption. The results of the present study will facilitate development of effective measures to produce safe aquatic products and meaningful suggestions for consuming aquatic products.     

Are children playgrounds safe play areas? Inorganic analysis and lead isotope ratios for contamination assessment in recreational (Brazilian) parks

Environmental Science and Pollution Research - In city playgrounds, there is a potential risk of harming children’s health by contamination coming from anthropogenic activities. With the aim...     

关于死海地区臭氧耗损现象(ODEs)的研究综述

自1997年在死海地区的大气边界层中观测到午间臭氧浓度迅速下降的现象后,研究学者们即对该地区的臭氧耗损现象(ozone depletion events,简称ODEs)展开了研究.而在此之前,大气边界层内的ODEs现象普遍被认为只会发生在极地地区的特殊大气现象.本文综述了关于死海地区ODEs研究的发展历史,主要展示了促...     

CuO/γ-Al_2O_3负载型催化剂催化燃烧处理油烟

采用等体积漫渍法制备不同CuO负载量的CuO/γ-Al2O3负载型催化剂,用X射线衍射仪、扫描电镜对该催化剂负载层活性组分的表面形态、晶相结构和颗粒大小进行表征,考察了该催化荆催化燃烧处理油烟的催化活性(以油烟净化效率表征).结果显示,催化活性随CuO负载量的增加.反应温度的升高而提高,但随烟气流量的增大而降低;在CuO负载量为20%(质量分数)、反应温度为350℃.烟气流量为5 L/min的最佳实验条件下,CuO/γ-Al2O3负载型催化剂的油烟净化效率最高.可达88.6%.该催化剂对油烟的催化燃烧具有较高的催化活性.     

Fenton氧化法降解丙烯酸废水的研究

利用废铁屑与H₂O₂形成的Fenton氧化反应来降解工业丙烯酸废水中的丙烯酸。在间歇反应器中,系统地考察了反应时间、H2O2浓度、液固比(废水质量∶固体质量)和反应温度对丙烯酸的降解率的影响,优选了工艺条件。在连续固定床反应器中进行了对比实验,以考察固液接触状态的影响及系统的稳定性。结果表明,废铁屑与H₂O₂构成的Fenton体系能有效地降解废水中的丙烯酸。在间歇工况下,适宜的条件为,液固比40∶1,温度20～25℃,H₂O₂浓度800 mg/L ,反应时间35 min,在此条件下,丙烯酸的降解率可达到95%以上。对比实验表明,固液接触状态对降解效果的影响不大,铁屑的性能稳定,在连续93 h的稳定性实验中,丙烯酸的降解率保持在90%左右。     

Heterogeneous reactivity of pyrene and 1-nitropyrene with NO2: Kinetics,product yields and mechanism

The heterogeneous reactivity of nitrogen dioxide with pyrene and 1-nitropyrene (1NP) adsorbed on silica particles has been investigated using a fast-flow-tube in the absence of light. Reactants and products were extracted from particles using pressurised fluid extraction (PFE) and concentration measurements were performed using gas chromatography/mass spectrometry (GC/MS). The pseudo-first order rate constants were obtained from the fit of the experimental decay of particulate polycyclic compound concentrations versus reaction time. Experiments were performed at three different NO₂ concentrations and second order rate constants were calculated considering the oxidant concentration. The following rate constant values were obtained at room temperature: k(NO₂ + pyrene) = (9.3 ± 2.3) × 10^?17 cm³ molecule^?1 s^?1 and k(NO₂ + 1NP) = (6.2 ± 1.5) × 10^?18 cm³ molecule^?1 s^?1, showing that the reactivity of 1NP was slower by a factor of 15 than that of pyrene. 1NP was identified as the only NO₂-initiated oxidation product of pyrene and all the three dinitropyrenes were identified in the case of the 1NP reaction. The product quantification allowed showing that the kinetics of oxidation product formation was equal to that measured for parent compounds degradation, within uncertainties, confirming the validity of the reaction kinetics measurements.