安徽省主要气象灾害趋势演变及其对粮食总产的影响

为了揭示安徽省主要气象灾害的现状和变化规律，保障粮食作物稳产高产。该文利用1986~2017年安徽省78个市、县的干旱、洪涝、风雹、低温冷冻害和雪灾等4类主要气象灾害的受灾、成灾率数据，采用气候倾向率、灰色关联度和R/S分析方法，分析了全省4类主要气象灾害的时空变化特征和未来发展趋势及其与粮食总产的关联度。结果表明：（1）全省4类气象灾害的受灾、成灾率均随年代呈下降趋势，近10年受灾、成灾率明显偏少；高值区多出现在淮北地区、皖南山区和大别山区，低值区大多出现在沿淮、江淮和沿江地区。（2）未来安徽省干旱受灾、成灾率将继续下降，洪涝将持续不明显的下降趋势，风雹、低温冷冻害和雪灾将由下降趋势转为平稳或略有上升的趋势。（3）4类气象灾害的受灾、成灾率与粮食总产量的关联度由高到低的排序均为: 洪涝、低温冷冻害和雪灾、干旱、风雹。由此说明洪涝是影响安徽省粮食生产最主要的气象灾害。     

Vaporization of heavy metals during thermal treatment of model solid waste in a fluidized bed incinerator

This paper investigated the volatilization behavior of heavy metals during thermal treatment of model solid waste in a fluidized bed reactor. Four metal chlorides (Cd, Pb, Cu and Zn) were chosen as metal sources. The influence of redox conditions, water and mineral matrice on heavy metal volatilization was investigated. In general, Cd shows significant vaporization especially when HCl was injected, while Cu and Pb vaporize moderately and Zn vaporization is negligible. Increasing oxygen concentration can lower heavy metal vaporization. Heavy metal interactions with the mineral matter can result in the formation of stable metallic species thus playing a negative effect on their behavior. However, HCl can promote the heavy metal release by preventing the formation of stable metallic species. The chemical sorption (either physical or chemical) inside the pores, coupled with the internal diffusion of gaseous metal species, may also control the vaporization process. With SO₂ injected, Cd and Pb show a higher volatility as a result of SO₂ reducing characteristics. From the analysis, the subsequent order of heavy metal volatility can be found: Cd > Cu ? Pb ? Zn.     

基于分子量分布的石化污水厂出水溶解性有机物性质研究

采用超滤膜法对某石化综合污水厂二级出水进行了分级,结合TOC、UV₂₅₄和三维荧光光谱分析,对不同分子量区间中的溶解性有机物的所占比例、物质特性和成分进行了研究。结果表明：污水厂二级出水中溶解性有机物分子量小于1 kDa的有机物所占比例最高,其DOC占原水DOC的92.7%。分子量为5和10 kDa的两种组分芳香构造化程度较高。三维荧光光谱分析表明,分子量大于1 kDa的溶解性有机物主要含有蛋白质类和腐殖质类物质,其中色氨酸类芳香族蛋白质所占比例较高。     

鸡蛋壳废料对水体中Cr(Ⅵ)的吸附特征与机理

利用鸡蛋壳废料对水中的Cr(Ⅵ)进行吸附处理,研究溶液pH、振荡时间、投加量和温度对鸡蛋壳废料吸附水体中Cr(Ⅵ)的特征和吸附机理。结果表明,在含有1 mg/L的Cr(Ⅵ)溶液的100 mL吸附体系中,鸡蛋壳废料可在30 min内完成吸附过程。溶液pH=2.5时,吸附量最大。鸡蛋壳投加量为1.0 g时,平衡吸附容量为0.0917 mg/g。利用鸡蛋壳去除水中Cr(Ⅵ)的最佳工艺参数为振荡时间30 min,初始pH为3.0,投加量2.0 g,体系温度35℃。鸡蛋壳对Cr(Ⅵ)的吸附过程用Langmiur和Freundlich方程能较好拟合,其中理论饱和吸附量在20℃、30℃和40℃时分别为0.1944、0.2034和0.2096 mg/g。吸附的焓变为8.76×10-3 kJ/mol,熵变为-45.96 J/(mol·K),吉布斯自由能变均为正值,变化范围是4.357~9.693 kJ/mol。鸡蛋壳对Cr(Ⅵ)的吸附过程主要为物理性的单分子层和多分子层吸附。     

Flow depth,velocity, and sediment motions in a straight widened channel with vegetated floodplains

Environmental Fluid Mechanics - Experiments were conducted in a straight channel that widens from a single channel to a compound channel based on a real navigation channel with a similar shape in a...     

湟水河流域气候变化特征及其影响

文章利用1961-2005湟水河流域9个气象台站气温、降水等地面观测资料,研究了湟水河流域气候变化及其对农业的影响。结果表明：湟水河流域2001—2005年比最冷的60年代四季平均气温分别偏高0．7-2．5℃,冬季增温比较显著;年降水量总体变化趋势是中游地区缓慢增加,而上游和下游地区则缓慢减少,流域内年平均降水量呈减少趋势;四季地表蒸发量均在增加,夏秋季大于其它季节;90年代湟水河流域秋季和春季降水的减少,使得秋季和春季发生中（重）干旱的频次明显增加。     

Effect of cadmium in the soil on growth,secondary metabolites and metal uptake in Salvia miltiorrhiza

We investigated the effect of Cd with different concentrations in soil (control, 0.5, 1.0, 1.5, and 2.0 mg kg^?1) on Salvia miltiorrhiza. The growth of S. miltiorrhiza was examined at 90 and 120 d, while active components were tested at 0, 30, 60, 90, and 120 d; Cd uptake was measured at days 0, 90, and 120. The biomass data indicated that high Cd concentration can stimulate the accumulation of biomass after a long treatment. The Cd content in the above- and below-ground parts strongly corresponds to the bioavailable Cd extracted by ethylene diamine tetraacetic acid (EDTA) and acetic acid. The Cd content in the below-ground parts of control approached the Cd standards given by World Health Organization after 120 d. The Cd content in the below-ground parts of S. miltiorrhiza at a Cd concentration of 0.5 mg kg^?1 exceeded the Cd standards after being grown for 90 and 120 days. The accumulation of hydrosoluble components in the above-ground parts appeared later than that in the below-ground parts. With longer treatment time, high Cd treatment promoted an accumulation of hydrosoluble and liposoluble components. The Cd content in the below-ground plant parts indicated that there was still a risk of exceeding the Cd limit for S. miltiorrhiza grown in the soil contaminated by low-concentration Cd after a long time.     

南水北调中线水源地汉江上游流域主要生态环境问题及对策

汉江上游是南水北调中线水源地,流域生态环境建设是保障水源地水质安全的关键.针对上游流域水环境污染、土地利用以及水土流失等重大生态环境问题,结合流域数字高程模型及水质调查对其进行了系统分析.结果表明:(1)丹江流域、库区流域及汉中盆地水质较差,COD<,Mn>和氨氮成为水源区主要污染物;(2)各子流域区植被覆盖占各自面积的71.2%～95.7%,表明流域植被覆盖较好,但沿河岸100 m范围内农业用地占29.2%～43.4%,且多为坡耕地;(3)流域水土流失严重,2000年左右流域侵蚀图显示汉江源头、秦岭南及大巴山北均出现了大片年均侵蚀模数>2 200 t/km2的区域,且有日益增强的趋势.提出加大水环境污染整治力度、加强农业用肥管理及河岸带建设、水土保持建设以及加强流域水环境及水土保持监测和科研工作等对策.     

基于循环经济的产品可持续发展研究

高新技术的迅速发展和市场环境的不断变化导致了产品更新换代速度的加快,加剧了资源消耗和环境污染。而基于循环经济的特征,开展产品可持续发展理论研究,可以指导产品自身的可持续协调发展,使产品由生产后的静态使用发展到性能或功能的可持续生长,可持续满足市场的全维需求。初步探讨了产品可持续发展的相关内涵、现状及其哲学意义,并分析了产品可持续发展的主要研究内容,对基于循环经济特点的产品可持续发展模式提出了初步讨论。     

苏州地区典型输变电工程电磁环境影响分析

结合电磁场的生态效应、输变电电磁辐射的环境影响分析度评价等，分析了苏州地区典型输变电工程电磁辐射的污染状况。说明220kV输变电工程电磁辐射没有超过居民区工频电场以度磁感应强度标准。