An examination of the effect of landscape pattern, land surface temperature, and socioeconomic conditions on WNV dissemination in Chicago

This paper developed an approach by the synthesis of remote sensing, landscape metrics, and statistical methods to examine the effects of landscape pattern, land surface temperature, and socioeconomic conditions on the spread of West Nile virus (WNV) caused by mosquitoes and animal hosts in Chicago, USA. Land use/land cover and land surface temperature images were derived from Terra’s Advanced Spaceborne Thermal Emission and Reflection Radiometer imagery. An analytical procedure using landscape metrics was developed, applying configuration analysis of landscape patterns in the study area. The positive reports of mosquitoes and animal hosts for WNV in fall, 2001–2006, were collected from the Cook County Public Health Department. Forty-nine municipalities were found to have WNV-positive records in mosquitoes and animal hosts in fall 2004. Socioeconomic data were obtained from the 2000 US Census. Statistical analysis was applied to WNV data in fall 2004 to identify the relationship between potential predictors and WNV spread. As a result, landscape factors, such as landscape aggregation index and the urban areas and areas of grass and water, showed strong correlations with the WNV-positive records. Socioeconomic conditions, such as the population over 65 years old, also showed a strong correlation with WNV-positive records. Thermal conditions of water showed a less but still considerable correlation to WNV-positive records. This research offers an opportunity to explore the effects of landscape pattern, land surface temperature, and socioeconomic conditions on the spread of WNV caused by mosquitoes and animal hosts. Results can contribute to public health and environmental management in the study area.     

The short-term effect of cadmium on low molecular weight organic acid and amino acid exudation from mangrove (Kandelia obovata (S., L.) Yong) roots

The aim of this study was to evaluate short-term concentration and time effects of cadmium on Kandelia obovata (S., L.) Yong root exudation, thereby evaluating and predicting the ecophysiological effects of mangrove to heavy metals at the root level. Mature K. obovata propagules were cultivated in a sandy medium for 3 months, and then six concentrations of Cd (0, 2.5, 5, 10, 20, and 40 mg L^?1) were applied. After exposure time of 24 h and 7 days, respectively, the root exudates of K. obovata were collected and low molecular weight organic acids (LMWOAs) and amino acids of which were analyzed. In addition, we measured glutathione, soluble protein content, and Cd concentration in the plant. We found 10 and 15 types of LMWOAs and amino acids in root exudates of K. obovata with total concentrations ranging from 29.54 to 43.08 mg g^?1 dry weight (DW) roots and from 737.35 to 1,452.46 ng g^?1 DW roots, respectively. Both of them varied in quality and quantity under different Cd treatment strengths and exposure times. Oxalic, acetic, l-malic, tartaric acid, tyrosine, methionine, cysteine, isoleucine, and arginine were dominant. Both LMWOAs and amino acids excreted from K. obovata roots play a key role in Cd toxicity resistance. The responsiveness of amino acids was less than that of LMWOAs. We suggest that the ecological effect of root-excreted free amino acids in the rhizosphere is mainly based on the role of nutrients, supplemented with detoxification to heavy metals.     

CS-Fe和CS-Fe/Ni的制备及其用于去除钴离子

以氯化铁为铁源,硼氢化钠为还原剂,壳聚糖为稳定剂,采用液相还原法制备壳聚糖稳定纳米铁（CS-Fe）;并以氯化铁为铁源,硫酸镍为镍源,硼氢化钠为还原剂,壳聚糖为稳定剂,采用液相还原共沉淀法制备壳聚糖稳定纳米铁镍（CS-Fe/Ni）。通过SEM、EDS、XRD、FT-IR等表征手段,对所制备的CS-Fe和CS-Fe/Ni的形貌及微观结构进行表征,并以Co²⁺为目标去除物评价CS-Fe和CS-Fe/Ni的反应活性。初步研究表明,制成的CS-Fe含有单质纳米铁,颗粒多数以30~90 nm球形颗粒为主;而CS-Fe/Ni材料中含有纳米铁镍,颗粒多数以30~60 nm球形颗粒为主;在相同的实验条件下,反应60 min,CS-Fe/Ni对Co²⁺的去除率高达100%,但是CS-Fe仅为88%,即CS-Fe/Ni对Co²⁺的去除率比CS-Fe高。     

Ti-天然沸石的钛掺杂取代法制备、表征和光催化性能

以酸处理脱铝后信阳天然斜发沸石为载体,硫酸钛、钛酸正丁酯和四氯化钛为钛源,分别采用浸渍法和气相法制备出钛掺杂沸石光催化剂。采用X-射线衍射和傅立叶红外光谱分析了沸石酸处理及钛取代前后结构。结果表明,80℃下,4 mol/L盐酸处理10 h后沸石结构发生了显著变化,但仍保持Al-O-Si骨架结构。红外光谱结果证明Ti4+与沸石形成稳定的Ti-O-Si键。在以300 W紫外灯为光源进行罗丹明B脱色反应,考察了含钛沸石的光催化活性。初始浓度为80 mg/L,光照1.5 h后罗丹明B的去除率为98.18%。     

Nocturnal NO3 radical chemistry in Houston,TX

Radical chemistry in the nocturnal urban boundary layer is dominated by the nitrate radical, NO₃, which oxidizes hydrocarbons and, through the aerosol uptake of N₂O₅, indirectly influences the nitrogen budget. The impact of NO₃ chemistry on polluted atmospheres and urban air quality is, however, not well understood, due to a lack of observations and the strong impact of vertical stability of the boundary layer, which makes nocturnal chemistry highly altitude dependent.Here we present long-path DOAS observations of the vertical distribution of the key nocturnal species O₃, NO₂, and NO₃ during the TRAMP experiment in Summer 2006 in Houston, TX. Our observations confirm the altitude dependence of nocturnal chemistry, which is reflected in the concentration profiles of all trace gases at night. In contrast to other study locations, NO₃ chemistry in Houston is dominated by industrial emissions of alkenes, in particular of isoprene, isobutene, and sporadically 1,3-butadiene, which are responsible for more than 70% of the nocturnal NO₃ loss. The nocturnally averaged loss of NO_x in the lowest 300 m of the Houston atmosphere is ～0.9 ppb h^?1, with little day-to-day variability. A comparison with the daytime NO_x loss shows that NO₃ chemistry is responsible for 16–50% of the NO_x loss in a 24-h period in the lowest 300 m of the atmosphere. The importance of the NO₃ + isoprene/1,3-butadiene reactions implies the efficient formation of organic nitrates and secondary organic aerosol at night in Houston.     

浙江省辐射环境监测现状及对策研究

辐射环境是生态环境的重要组成部分,核与辐射环境安全是国家环境安全的重要内容.详述了目前浙江省辐射环境监测网络的建设情况,以及对核设施、铀矿及伴生矿放射性污染源、核技术运用、电磁辐射环境、辐射应急等进行辐射环境监测的情况,分析了存在的主要问题,并提出了相应的对策,为浙江省辐射环境监管提供技术支撑和科学依据,同时也对全国辐射环境监测和管理具有积极的指导意义.     

Determination of polybrominated diphenyl ethers (PBDEs) in fish samples from rivers and estuaries in Taiwan

Polybrominated diphenyl ethers (PBDEs) have been used extensively over the past two decades as flame retardants in many types of polymers, and have been found to be a class of contaminants of concern. Measurements of PBDEs in various environmental matrices from Sweden, Holland, Japan, North America, and elsewhere have been reported. We report data of PBDEs in fish samples taken from six rivers and three estuaries in Taiwan. Seven PBDE congeners were observed in all sixty samples. BDE-47 was found to be the dominant congener in all waters, and BDE-154 contributed more than BDE-99 and BDE-100. Nonetheless, BDE-154 and BDE-183 were the predominant congeners in some species studied. These results are somewhat different from those from other countries, where the pattern is typically BDE-47 > 99 >100 >154, 153, and is postulated to be due to the extensive use of octa-BDE rather than penta-BDE in Taiwan. The average concentration distribution across all samples of the sum of PBDE congeners ranged from 30.6 ng/g lipid to 281 ng/g lipid. The concentrations of PBDEs in fishes reported here are higher than those reported from European countries, but lower than those from the United States.     

Copper uptake by four Elsholtzia ecotypes supplied with varying levels of copper in solution culture

The effects of copper (Cu) on the yield and Cu uptake of three ecotypes of Elsholtzia splendens and one of Elsholtzia argyi were studied using solution culture. Three Cu concentrations were compared: 0.31 (control), 50 and 100 micromol L(-1). Although E. argyi took up more Cu in the aboveground parts, typical visual symptoms of Cu toxicity appeared when the plants grew in 50 and 100 micromol Cu L(-1). In contrast, plants from all three populations of E. splendens showed high Cu tolerance and substantial shoot Cu accumulation of 58-144 mg kg(-1). Shoot Cu concentrations were about 16-27 times higher than root Cu concentrations. Root-to-shoot ratio of the E. argyi ecotype was halved when Cu was supplied at a level of 100 mg L(-1) compared to the control (0.31 mg L(-1)) but the ratio increased by 6-47% in the three E. splendens ecotypes. The increase in root-to-shoot ratio in E. splendens may be a mechanism by which the plants can tolerate high Cu concentrations. There were few differences in morphology among the three E. splendens ecotypes in response to added Cu. The results are discussed in relation to the possible use of E. splendens as a pioneer species in the phytostabilization of Cu-contaminated soils.     

中国水利水电工程开发与区域可持续发展

本文论述了中国水利水电工程开发与区域可持续发展的关系,并提出了中国实现可持续的水利水电工程开发的主要对策。     

活性炭纤维在机动车尾气净化中的研究与应用展望

机动车尾气净化控制的一个难点在于冷启动阶段,此时由于温度较低,催化剂尚未完全起作用,导致排出的污染物浓度较高。阐述了活性炭纤维的基本特性,特别是其低温吸附与催化性能对NO和CO的转化作用,讨论了活性炭纤维作为机动车尾气净化材料所需的改性及方法,并展望了其应用前景。