天津市可吸入颗粒物及元素室内外相关性

选取天津市某社区作为采样点,于2009年8、9月(代表非采暖季)和11、12月(代表采暖季)采集了室内和室外可吸入颗粒物(PM10)样品,以研究天津市PM10及元素的室内外相关性.结果表明,采暖季PM10的室外平均浓度为198.88μg/m3.非采暖季和采暖季PM10的室内外浓度比(I/O比值)的变化范围分别为0.14~3.22和0.10~3.70,平均值分别为0.88和0.96,室内外相关系数(R2)分别为0.32和0.46.Al、Ca、Fe等元素的浓度均高于1μg/m3,V、Mn、Cu等元素浓度变化范围为0.01~1μg/m3;非采暖季和采暖季元素I/O比值的变化范围分别为0.62~1.04和0.41~0.92.以采暖季为例,使用PM10质量(元素)浓度的质量平衡模型计算的有效穿透因子(Finf)、贡献值、贡献率分别为0.26(0.39)、50.84μg/m3(78.69μg/m3)、43.97%(50.05%),两种结果存在差异的原因是2种模型对Finf的假设不同.     

胶州湾盐沼CH3I通量的季节特征及其影响因素

为了探究胶州湾盐沼碘甲烷(CH_3I)的排放通量、排放规律及其影响因素,在2016年7月—2017年5月期间,采用静态箱法-气相色谱法对CH_3I进行了观测.结果表明,胶州湾盐沼显示为CH_3I的排放源.互花米草湿地(S区)CH_3I通量均值为9.61 nmol·m~(-2)·d~(-1),光滩(M区)CH_3I通量均值为6.63 nmol·m~(-2)·d~(-1).CH_3I的排放通量在S区与M区之间存在明显区别,S区CH_3I通量在夏、秋季较高,最高值出现在夏季;而M区CH_3I通量在冬、春季较高,最高值出现在冬季.S区与M区各月CH_3I通量总体呈相反的变化趋势,且S区与M区CH_3I通量的最大值和最小值都出现在7月.胶州湾盐沼环境因素较为复杂,因此,CH_3I排放通量的影响因素并不单一.土壤TN、pH、温度及互花米草对CH_3I通量的影响较为显著,而含水量、盐度及其他养分状况等对CH_3I通量也有一定的作用.此外,冻融过程及潮汐作用的影响也不容忽视.     

典型山核桃产区土壤重金属空间异质性及其风险评价

山核桃(Carya cathayensis)是我国特有的高档干果和木本油料植物,目前关于山核桃林地土壤重金属污染研究鲜有报道.本研究以典型山核桃产区临安为研究区,系统采集了188个山核桃土壤样品,采用地统计学以及Moran's I等空间分析方法研究土壤重金属的空间异质性,并对山核桃林土壤重金属潜在生态风险进行评价.结果表明,重金属Cd、Cu、Zn、Pb、Ni、Cr平均含量分别为0.37、40.76、87.61、30.10、28.33、56.57 mg·kg-1,其中Cd、Cu平均值分别是背景值的1.33和2.87倍.单因子污染指数、内梅罗污染指数及潜在生态风险评价结果显示研究区土壤重金属均有样点超过土壤背景值,且Cd、Cu、Zn、Pb、Ni有部分样点超过土壤环境质量二级标准,表明研究区土壤已具有Cd、Cu、Zn、Pb、Ni、Cr不同程度的累积特征,局部土壤已受到Cd、Cu、Zn、Pb、Ni的污染,其中Cd最为严重,达到了强生态危害程度,Cu次之,总体上重金属呈中等生态危害程度.基于半方差函数分析得出,Cd、Cu、Pb、Ni、Cr具有强烈的空间自相关,而Zn属于中等空间相关性.Moran's I指数以及克里格插值结果揭示重金属Cd、Cu、Zn、Pb、Ni、Cr均存在明显的空间分布格局和局部空间聚集现象,高值主要集中在太阳、岛石、清凉峰、河桥以及湍口几个乡镇,且以重金属Cd、Cu污染风险概率较高.土壤Cd、Cu、Zn、Ni、Cr高值分布主要与矿区开采有关,而Pb与钾肥的施用密切相关.可见,研究区重金属空间分布特征受人为活动影响明显.     

土壤细菌荧光原位杂交对比染色技术的构建

荧光原位杂交技术(FISH)已经成为研究海洋、湖泊及河流沉积物微生物特征的重要手段,但对土壤的应用尚存在局限性。研究以土壤和堆肥为材料,筛选了FISH对比染色荧光剂,并对其染色条件进行了分析。研究结果表明,1/200稀释SYBR Green(ISGI)可用于FISH的对比染色。其染色时间为1 min,封片试剂为无荧光浸镜油。     

Urban afforestation and infant health: Evidence from MillionTreesNYC

This paper examines the impact of urban afforestation on infant health outcomes by exploiting a quasi-experimental setting where one million new trees were planted in New York City (NYC), but not in counties surrounding NYC over the same time period. Using a near-universal birth record of NYC and surrounding counties over 2004–2015 and employing both the synthetic control method and a difference-in-differences model, we find that an approximately 20% increase in urban forest cover decreased prematurity and low birth weight among mothers in NYC by 2.1 and 0.24 percentage points, respectively, relative to similar mothers outside of NYC. The low birth weight finding is equivalent to getting a mother smoking two cigarettes a day during pregnancy to quit. An internal validity test suggests that changes in the composition of NYC mothers cannot explain the observed effects. Additionally, we find evidence that declines in PM_2.5 concentrations and increases in outdoor walks are potential causal mechanisms. Results suggest that urban afforestation may be able to complement existing policies aimed at improving infant health.     

不同质量浓度黄莒蒲和狭叶香蒲对铜绿微囊藻的化感作用

分别采用黄菖蒲（IrispseudacorusL．）、狭叶香蒲（TyphaangustifoliaL．）和铜绿微囊藻（Microcystisaeruginosa）共生培养的实验方法研究了不同质量浓度黄菖蒲、狭叶香蒲对铜绿微囊藻的化感作用。结果表明,黄菖蒲在质量浓度大于10g／L时对初始密度为1．0×10^7ind／mL的铜绿微囊藻具有较好的抑制作用,表现为黄菖蒲质量浓度为10、20和40g／L时,第15天对铜绿微囊藻的抑制率分别为30．1％、51．8％和84．0％;狭叶香蒲在质量浓度大于20g／L时对铜绿微囊藻有明显的抑制作用,表现为狭叶香蒲质量浓度为20g／L和40g／L时,第15天对铜绿微囊藻的抑制率分别为34．2％和77．7％,实验过程中,铜绿微囊藻叶绿素a含量逐渐减少,而藻密度、SOD活性及MDA含量先增加后逐渐降低,表明经过一段时间持续地化感胁迫,黄菖蒲和狭叶香蒲可以诱导铜绿微囊藻产生氧化胁迫,导致细胞结构严重损伤和叶绿素大量分解,从而强烈抑制铜绿微囊藻的生长。     

Performance analysis of bioethanol (Water Hyacinth) on diesel engine

The increasing consumption and excessive extraction of conventional fuels is the matter of serious concern. Nowadays, world is looking for alternative sources of fuel which can partially replace conventional fuel dependence. The current investigation intends to provide evaluation of bio-ethanol preparation from Water Hyacinth (WH) and its influence on diesel engine performance under various operating conditions. This study explores the extraction of glucose from WH (Eichhornia crassipes) pretreated with sulfuric acid (H₂SO₄) for production of bio-ethanol. For the production of bio-ethanol different concentrations of H₂SO₄ acid hydrolysate (1%, 2%, 4%, 6%, 8%, and 10%) were prepared which was then followed by fermentation with cellulose fermenting yeasts. From results, it was observed that 4% H₂SO₄ acid hydrolysis produces higher concentrations of ethanol than other concentrations. Bio-ethanol extracted from WH was blended with diesel in different proportions (5%, 10%, 15%, 20%, and 25%) v/v and performance and emissions were experimentally investigated on single cylinder diesel engine under various load conditions. Experimental results show that 5 BED [5% bio-ethanol (WH + 95%diesel v/v) and 10BED (10% bio-ethanol (WH + 90%diesel v/v)] produces higher brake power, brake thermal efficiency and brake mean effective pressure with improved exhaust emission profiles than any other blend.     

环境一号卫星环境应用系统工程及其关键技术研究进展

简介长达11年的国家重点项目“环境一号卫星环境应用系统工程及其关键技术研究”的核心内容及其重要研究成果,对环境一号卫星系统需求分析、设计理论、研制发射和运行应用全过程进行了完整的研究与实践,为环境一号卫星系统的建设、应用和业务运行奠定了重要基础。     

Measured elemental transfer factors for boreal hunter/gatherer scenarios: fish, game and berries

The environmental assessment of long-term nuclear waste management requires data to estimate food chain transfers for radionuclides in various environmental settings. For key elements such as iodine (I) and chlorine (Cl), there is a paucity of transfer factor data, particularly outside of agricultural food chains. This study dealt with transfers of I, Cl and 28 other elements to foods that would be typical of boreal hunter/gatherer lifestyles, as well as being common foods for modern recreational and subsistence hunters. Food/substrate concentration ratios (CRs) and related transfer factors for eight species of widely distributed fish, whitetail deer (Odocoileus virginianus), Canada geese (Branta canadensis) and wild blueberries (Vaccinium myrtilloides) were measured and compared to the literature. Limited data were obtained for caribou (Rangifer tarandus), elk (Cervus elaphus) and moose (Alces americanus). Freshwater sediment Kd values and CRs for a ubiquitous freshwater macrophyte were also obtained. The CRs for I in fish were 29 L kg⁻¹ in edible muscle (fillets) of large-bodied species and 85 L kg⁻¹ for whole, small-bodied fish. The log CRs for fish and macrophytes were correlated across elements. For several elements, the Kds for sediments in deep water were ∼4-fold higher than for littoral samples. The elemental transfers to wild animals for some elements were notably different than the literature indicates for domestic animals. It is argued that the transfer data obtained using indigenous elements from real environmental settings, as opposed to contaminant elements in experimental or impacted environments, are especially relevant to assessment of long-term impacts.     

Evaluating Kriging as a Tool to Improve Moderate Resolution Maps of Forest Biomass

The USDA Forest Service, Forest Inventory and Analysis program (FIA) recently produced a nationwide map of forest biomass by modeling biomass collected on forest inventory plots as nonparametric functions of moderate resolution satellite data and other environmental variables using Cubist software. Efforts are underway to develop methods to enhance this initial map. We explored the possibility of modeling spatial structure to make such improvements. Spatial structure in the field biomass data as well as in residuals from the map was investigated across 18 ecological zones in the Interior Western U.S. Exploratory tools included directional graphs of summary statistics, three dimensional maps, Moran’s I correlograms, and variograms. Where spatial pattern was present, field and residual biomass were kriged, and predictions made for an independent test set were evaluated for improvement over predictions in the initial biomass map. While kriging has some potential benefit when analyzing the field data and exploring spatial structure, kriging residuals resulted in little or no improvement in the initial biomass map developed using Cubist software. Stationarity assumptions, variogram behavior, and appropriate model fitting strategies are discussed.