A Simulation of Temporal and Spatial Variations in Carbon at Landscape Level: A Case Study for Lake Abitibi Model Forest in Ontario,Canada

Using a case study of the Lake Abitibi Model Forest (LAMF), this study aims to assess the temporal and spatial variability in carbon storage during 1990–2000, and to present a comprehensive estimation of the carbon budget for LAMF's ecosystems. As well, it provided the information needed by local forest managers to develop ecological and carbon-based indicators and monitor the sustainability of forest ecosystems. Temporal and spatial carbon dynamics were simulated at the landscape level using ecosystem model TRIPLEX1.0 and Geographical Information System (GIS). The simulated net primary productivity (NPP) and carbon storage in forest biomass and soil were compared with field data and results from other studies for Canada's boreal forests. The results show that simulated NPP ranged from 3.26 to 3.34 tC ha⁻¹ yr⁻¹ in the 1990s and was consistent with the range measured during the Boreal Ecosystem-Atmosphere Studies (BOREAS) in central Canada. Modeled NPP was also compared with the estimation from remote sensing data. The density of total above-and belowground biomass was 125.3, 111.8, and 106.5 tC ha⁻¹ for black spruce, trembling aspen, and jack pine in the LAMF ecosystem, respectively. The total carbon density of forested land was estimated at 154.4 tC ha⁻¹ with the proportion of 4:6 for total biomass and soil. The analysis of net carbon balance of ecosystem suggested that the LAMF forest ecosystem was acting as a carbon sink with an allowable harvest in the 1990s.     

三价砷和五价砷对活性污泥几种酶活性的影响

应用静态试验,研究了As(Ⅲ),As(Ⅴ)对活性污泥脱氢酶活性、脲酶活性、蛋白酶活性的影响。其结果:抑制10%脱氢酶、脲酶、蛋白酶活性的As(Ⅲ)浓度分别为10.0mg/gMLSS,13.4mg/gMLSS,2.6mg/gMLSS;As(Ⅴ)的浓度则分别为552.6mg/gMLSS,464.4mg/gMLSS,193.7mg/gMLSS。As(Ⅲ)对活性污泥的毒性比As(Ⅴ)平均大53倍。     

武夷新区土地利用变化及景观格局研究

以2010年的LandsatTM遥感影像图和武夷新区总体规划中新区2030年土地利用规划图为基础数据,在RS和GIS技术支持下,结合马尔科夫模型和景观生态学方法分析了未来武夷新区的土地利用与案观格局变化。结果表明：在规划实施后,建设用地通过占用耕地和林地而大面积增加,使得林地和耕地相应减少,人类活动对景观的干扰强度增大,区域景观斑块形状趋于规则简单化,斑块总数有所减少,平均斑块面积增大,景观连接度增强,破碎化程度降低,景观多样性增加。     

杭州城区环境空气中二口恶英浓度状况研究

依据2009年7月至2012年2月连续3年对杭州城区环境空气中二英（PCDD/Fs）采样分析结果得知,杭州城区环境空气中二英毒性当量质量浓度变化范围为0.13～0.55 pg TEQ/m³,均值为0.34 pg TEQ/m³。城区环境空气中二英浓度季节变化不显著,夏季略低于冬季;城区范围内不同功能区之间二英浓度差别不显著;连续3年监测结果未显现二英年度变化趋势。沙尘暴天气环境空气中二英浓度显著增高,日常天气和烟花爆竹集中燃放天气环境空气中二英形态分布存在明显区别,烟花爆竹集中燃放期间八氯代二苯并-对-二英（OCDD）占总质量浓度比例显著提高。利用IBM SPSS Statistics 19.0统计软件对24个监测结果聚类分析发现,杭州城区环境空气中二英的同类物分布具有明显的“源”分布特征。     

浙江东阳市环境污染现状,趋势及其对策

随着东阳市经济的迅速发展．由于人口数量增加，对自然资源的需求量越来越大，环境保护意识薄弱等原因，导致生态系统遭到破坏，林相单一、水土流失严重、洪旱灾害频繁、环境污染严重等灾害。据此，本文提出保护东阳市环境的对策。     

活性炭纤维阴极产生H_2O_2的影响因素研究

考察了电流密度、pH值、曝气量、电解质Na_2SO_4浓度等工艺条件对活性炭纤维(ACF)阴极产生H_2O_2的影响规律。通过测定N_2吸附-脱附等温线和扫描电子显微镜(SEM)等手段观察了ACF的微观结构,从微观结构角度探讨了ACF阴极产生的优势与机理。结果表明,ACF孔隙结构丰富,比表面积大,有利于氧气分子在电极表面及孔道内的吸附-还原过程。当电流密度为5 m A/cm~2,pH=3,曝气量400 m L/min,电解质Na_2SO_4浓度为0.05 mol/L时,电解180 min还原产生H_2O_2的质量浓度高达27.86 mg/L。     

Haloacetic acids in swimming pool and spa water in the United States and China

The objective of this study is to investigate the occurrence of haloacetic acids （HAAs）, a group of disinfection byproducts, in swimming pool and spa water. The samples were collected from six indoor pools, six outdoor pools and three spas in Pennsylvania, the United States, and from five outdoor pools and nine indoor pools in Beijing, China. Five HAAs （HAA5）, including monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid, and dibromoacetic acid were analyzed. Total chlorine, pH and total organic carbon concentration were analyzed as well. Results indicated that the levels of HAA5 in swimming pools and spas in the United States ranged from 70 to 3980μg·L^-1, with an arithmetic average at 1440μg·L^-1 and a median level at 1150μg·L^-1. These levels are much higher than the levels reported in chlorinated drinking water and are likely due to organic matters released from swimmers＇ bodies. The levels of HAA5 in swimming pools in China ranged from 13 to 332μg·L^-1, with an arithmetic average at 117μg·L^-1 and a median level at 114μg·L^-1. The lower HAA levels in swimming pools in China were due to the lower chlorine residuals. Results from this study can help water professionals to better understand the formation and stability of HAAs in chlorinated water and assess risks associated with exposures to HAAs in swimming pools and spas.     

黑曲霉β-葡萄糖苷酶的筛选、克隆及表达

从曲霉属10株试验菌中筛选得到一株产β-葡萄糖苷酶活性较高的黑曲霉FTA-008.该菌株在适宜的培养条件下,β-葡萄糖苷酶的最高活性达2.89 U/mL,适宜产酶周期为3 d.通过设计特异引物,以该菌株的总RNA为模板,采用RT-PCR技术获得大小为2 511 bp的cDNA片段,该序列与GenBank中AJ132386的β-葡萄糖苷酶序列相比,氨基酸序列同源性达96.8%.经毕赤酵母表达,β-葡萄糖苷酶比活力达7.85 U/mg.图3表1参13     

Spatial and seasonal variations in bacterial communities of the Yellow Sea by T-RFLP analysis

Four typical coastal sites (rocky shore, sandy shore, mud flat shore, and artificial harbor) at the Yellow Sea were chosen to investigate the spatial and seasonal variations in bacterial communities. This was accomplished by using terminal restriction fragment length polymorphism (T-RFLP) analysis of PCR amplified 16S rDNA fragments. Two kinds of tetrameric restriction enzymes, HhaI and MspI, were used in the experiment to depict the bacterial community diversity in different marine environments. It was found that the community compositions digested by the two enzymes separately were different. However, the results of bacterial community diversity derived from them were similar. The MDA analysis results of T-RFLP profiles coming from HhaI and MspI both exhibited a significant seasonal community shift for bacteria and a relatively low spatial variation among the four locations. With HhaI as the sample, the pair wise T-tests also revealed that variations were minor between each pair of marine environments, with R ranging from 0.198 to 0.349. However, the bacterial community structure in the mud flat site depicted a larger difference than each of the other three sites (R ranging from 0.282 to 0.349).     

基于遥感的青岛市城市热岛时空变化特征

随着城市化进程的加快,城市热岛现象日渐突出,给人类生产生活带来很大影响,成为当今社会的热点问题。本文根据2001年1月—2012年12月共416幅8天合成地表温度产品MOD11A2遥感影像,以UHIER指数为划分标准,采用密度分割法对地表温度进行等级分类,并运用相关分析、空间叠加分析和景观格局指数分析等方法,分析了青岛市城市热岛在日、季节及年际等时间尺度的变化规律和空间分布特征。结果表明:(1)在时间变化特征方面,城市热岛具有昼弱夜强的日变化特征;季节尺度上,表现为冬强夏弱,高温区所占面积比例分别为8.66%和5.07%;年际尺度上,热岛范围呈现出逐年增大的特点,高温区面积以每年15%的速率增加。(2)在空间特征方面,城市热岛主要集中在青岛市区、即墨市南部、胶州市中部以及黄岛区东部;对城市热岛的景观格局分析发现,青岛市地表温度向高温化、集中化趋势发展。