Electrocatalytic degradation of sulfamethylthiadiazole by GAC@Ni/Fe three-dimensional particle electrode

Environmental Science and Pollution Research - In this work, GAC@Ni/Fe particle electrodes were prepared and employed for the degradation of sulfamethylthiadiazole (SMT) by three-dimensional...     

Improved prediction for a spatio-temporal model

Environmental and Ecological Statistics - We investigate a framework for improving predictions from models for spatio-temporal data. The framework is based on minimising the mean squared prediction...     

Lead contamination in tea garden soils and factors affecting its bioavailability

The consumption of heavy metals is detrimental to human health and most countries restrict the concentration of metals such as lead (Pb) in food and beverages. Recent tests have detected high Pb concentrations in certain commercial brands of tea leaves and this finding has raised concerns for both producers and consumers. To investigate what factors may be contributing to the increase in Pb accumulation in the tea leaves we collected tea leaves and soils from tea producing areas and analyzed them for Pb concentration, pH and organic matter content. The result showed the Pb concentration of 47% investigated tea leaves samples was beyond 2 mg kg(-1), the permissible levels given by China. The total Pb concentration in the surface and subsurface soil layers averaged 36.4 and 32.2 mg kg(-1), respectively which fall below of the 60 mg kg(-1) limit provided for organic tea gardens in China. The pH of the tea garden soils was severely acidic with the lowest pH of 3.37. Soils under older tea gardens tended to have a lower pH and a higher Pb bioavailability which was defined as the amount of lead extracted by CaCl2 solution than those under younger tea gardens. We found that the concentration of bioavailable Pb and the percentage of bioavailable Pb (bioavailable Pb relative to total Pb concentration) were positively correlated with soil H+ activity and soil organic matter content, and the organic matter accumulation contribute more effects on Pb bioavailability in these two factors. We conclude that soil acidification and organic matter accumulation could contribute to increasing Pb bioavailability in soil and that these could increase Pb uptake and accumulation in the tea leaves.     

棉铃虫核多角体病毒基因组限制酶酶切分析及其多角体基因的定位

应用１１种限制性内酶ＢａｍＨⅠ、ＢｓｔＥⅡ、ＥｃｏＲⅠ、ＥｃｏＲⅤ、ＨｉｎｄⅢ、ＫｐｎⅠ、ＰｓｔⅠ、ＳａｌⅠ、ＳｓｔⅠ、ＸｂａⅠａⅠ和ＸⅠⅠ和ＸｈｏⅠ分别将中国棉铃虫核多角体病毒（单粒包埋ＨａＳＮＰＶ）湖北株基因组Ｄ组ＤＮＡ酶切为１０、１２、２２、２１、１３、６、６、４０、６、２１、６个片段，并求得基因组大小平均为１什什Ｍｒ≈７９．１×１０６．以家委核多角体病毒ＢｍＮＰＶ多角体基因为探针，利用Ｓｏｕｔｈｅｒｎ杂交技术将病毒多角体基因定位在ＳａｌⅠ４．２×１０３ｂ左右的片段上．与棉铃虫核多角体病毒其它株系酶切图谱比较结果表明，本株病毒与上海等株系及美洲棉铃虫核多角体病毒ＨａＳＮＰＶＥｌｋａｒ株系酶切图谱相似，它们之间的条带数和大小差异较小，而与已发现的所有多粒包埋型病毒ＨａＳＮＰＶ酶切图主谱差异较大．据此认为ＨａＳＮＰＶ和ＨａＭＮＰＶ属于基因型不同的两类病毒，而ＨａＳＮＰＶ不同分离株的同源性很高     

中国西北干旱区水资源利用及其生态环境问题

近５０年来,西北干旱区随水土资源开发利用规模的不断扩展,使区域内工农业与经济得以稳定持续发展。但同时,引起一系列生态环境变化。①大多数河流下游水量锐减,甚至断流,河道缩短,终端湖泊萎缩或干涸,水质咸化和污染趋势加剧；②土壤沙漠化和盐碱化,沙漠化土地面积达６７４９３×１０^４ｈｍ^２,盐碱化耕地面积逾１３５５６×１０^４ｈｍ^２；③植被退化,生物多样性减少,与５０年代初相比,天然森林面积减少４９％～５８％,草地面积减少１６％～９２％；④沙尘暴灾害发生频数增加,灾害程度加剧。节约与高效化利用水资源以及生态环境效益与经济效益间统一协调是西北干旱区可持续发展的根本途径     

"三S"技术应用与环境科技发展

叙述了遥感，全球定位系统和地理信息系统和环境科技发展的关系，以及在环境科技中的实际应用，提出了在大力开展集ＲＳ，ＧＰＳ，ＧＩＳ于一体，适合环境科学应用的，综合多功能的“三Ｓ”技术，以适应可持续发展的需要。     

两种垃圾处理设施挥发性恶臭气体的指纹谱

为研究垃圾转运、焚烧处理设施挥发性有机污染物排放现状,采用GC-MS(气相色谱质谱联用仪)方法分析了垃圾处理设施不同采样点臭气中物质组成及主要组分含量。在所采集的样品中定量分析了111种物质,从中筛选21种物质并根据其归一化浓度建立了各采样点的指纹谱图。结合物质嗅阈值和指纹谱分析,初步识别了不同处理设施采样点的典型恶臭污染物,其中垃圾转运站站内包括对二甲苯、间二甲苯、邻二甲苯、二甲基二硫醚,站外包括甲苯、乙苯、二硫化碳、甲硫醇;垃圾焚烧厂渣坑为甲硫醚,渗滤液为硫化氢。     

Atmospheric sulfur hexafluoride in-situ measurements at the Shangdianzi regional background station in China

We present in-situ measurements of atmospheric sulfur hexafluoride（SF6） conducted by an automated gas chromatograph–electron capture detector system and a gas chromatography/mass spectrometry system at a regional background site, Shangdianzi,in China, from June 2009 to May 2011, using the System for Observation of Greenhouse gases in Europe and Asia and Advanced Global Atmospheric Gases Experiment（AGAGE）techniques. The mean background and polluted mixing ratios for SF6 during the study period were 7.22 × 10-12（mol/mol, hereinafter） and 8.66 × 10-12, respectively. The averaged SF6 background mixing ratios at Shangdianzi were consistent with those obtained at other AGAGE stations located at similar latitudes（Trinidad Head and Mace Head）, but larger than AGAGE stations in the Southern Hemisphere（Cape Grim and Cape Matatula）. SF6 background mixing ratios increased rapidly during our study period, with a positive growth rate at 0.30 × 10-12year-1. The peak to peak amplitude of the seasonal cycle for SF6 background conditions was 0.07 × 10-12, while the seasonal fluctuation of polluted conditions was 2.16 × 10-12. During the study period, peak values of SF6 mixing ratios occurred in autumn when local surface horizontal winds originated from W/WSW/SW/SWS/S sectors, while lower levels of SF6 mixing ratios appeared as winds originated from N/NNE/NE/ENE/E sectors.