萍乡蔬菜种植区土壤中重金属含量及潜在生态危害研究

为了解萍乡蔬菜种植区土壤环境质量和污染状况,采用综合污染指数法和潜在生态危害指数法对采样区土壤的环境质量进行了评价.结果表明,所有重金属的均值均未超过土壤环境质量标准中的二级标准,其单项污染指数依次为Hg>Ni>Cd>Cu>Zn>Pb>As>Cr,其中Cd、Hg、Pb、Ni含量均高于对应元素的江西省土壤重金属背景值,但土壤的综合污染指数和潜在生态危害指数都较低.总的来说,萍乡蔬菜种植区土壤环境质量处于清洁和安全范围内,生态风险较低.     

三江平原湿地保护面临的问题及可持续发展战略研究

湿地是地球上最重要的生态系统类型之一,湿地保护工作的重要性已受到社会各界的高度重视.三江平原作为中国面积最大的淡水沼泽湿地分布区,其湿地保护工作尤为重要.目前,三江湿地的保护工作面临持续破坏、永续保护与经济发展之间矛盾突出及保护工作与时俱进有待提高等方面的问题.需继续坚持湿地保护与恢复重建,并在立法保护湿地、湿地生态补偿和加强湿地保护队伍建设等方面开展工作,实现湿地资源利用的可持续发展.     

Soil Carbon Sequestration Potential for “Grain for Green” Project in Loess Plateau,China

Conversion of cropland into perennial vegetation land can increase soil organic carbon (SOC) accumulation, which might be an important mitigation measure to sequester carbon dioxide from the atmosphere. The “Grain for Green” project, one of the most ambitious ecological programmes launched in modern China, aims at transforming the low-yield slope cropland into grassland and woodland. The Loess Plateau in China is the most important target of this project due to its serious soil erosion. The objectives of this study are to answer three questions: (1) what is the rate of the SOC accumulation for this “Grain for Green” project in Loess Plateau? (2) Is there a difference in SOC sequestration among different restoration types, including grassland, shrub and forest? (3) Is the effect of restoration types on SOC accumulation different among northern, middle and southern regions of the Loess Plateau? Based on analysis of the data collected from the literature conducted in the Loess Plateau, we found that SOC increased at a rate of 0.712 TgC/year in the top 20 cm soil layer for 60 years under this project across the entire Loess Plateau. This was a relatively reliable estimation based on current data, although there were some uncertainties. Compared to grassland, forest had a significantly greater effect on SOC accumulation in middle and southern Loess Plateau but had a weaker effect in the northern Loess Plateau. There were no differences found in SOC sequestration between shrub and grassland across the entire Loess Plateau. Grassland had a stronger effect on SOC sequestration in the northern Loess Plateau than in the middle and southern regions. In contrast, forest could increase more SOC in the middle and southern Loess Plateau than in the northern Loess Plateau, whereas shrub had a similar effect on SOC sequestration across the Loess Plateau. Our results suggest that the “Grain for Green” project can significantly increase the SOC storage in Loess Plateau, and it is recommended to expand grassland and shrub areas in the northern Loess Plateau and forest in the middle and southern Loess Plateau to enhance the SOC sequestration in this area.     

空间数据挖掘的应用技术

空间数据挖掘技术是数据挖掘技术与空间数据库技术的融合,在GIS遥感、图像数据库、医疗影像处理等领域具有广阔的应用前景。基于空间数据挖掘的特点,论述了其在GIS中的应用,指出了空间数据挖掘面临的问题,并阐述了空间数据挖掘的发展趋势。     

GB8965.1-2009《防护服装阻燃防护第一部分:阻燃服》新增项目的探讨

本文对GB8965.1-2009《防护服装阻燃防护第一部分:阻燃服》标准的特点、整体框架、新增项目的目的及内容进行具体阐述,并提出标准修订及实施的建议。     

苍耳子的化学成分

苍耳子(Fructus Xanthii)是常用中药,主要用于慢性鼻炎的治疗,有一定的毒性.为明确苍耳子产生生物活性的物质基础,通过溶剂萃取、正、反相反复硅胶柱色谱及MCI柱色谱等方法,对苍耳子80%甲醇提取物进行分离纯化,用质谱、核磁共振谱等方法进行结构鉴定.从正丁醇萃取物中分离鉴定7个化合物:阿魏酸(1)、咖啡酸(2)、绿原酸(3)、4-O-咖啡酰奎宁酸甲酯(4)、6,7-二甲基-1,4-二氢-2,3-喹喔啉二酮(5)、咖啡酸胆碱酯(6)和4′-O-二氢红花菜豆酸钠盐-β-D-葡萄糖苷(7).其中,化合物4~7为首次从该植物中分离得到.图1参10     

Transition to Lead-Free Products in the US Electronics Industry: A Model of Environmental,Technical, and Economic Preferences

The European Union’s Restriction on the Use of Certain Hazardous Substances (Directive 2002/95/EC) targeted at electronic products took effect in 2006. In contrast, the USA has no comparable national policy on these products. To understand corporate responses to policy differences across jurisdictions, we conducted a structured-questionnaire survey of individuals in 109 companies that are representative of the US electronics industry. The results reveal that 70% of these companies have already adopted lead-free solder for electronics with 49% of the total preferring the SnAgCu formulation, despite uncertainties associated with environmental impacts of this alternative alloy. We use a modified life cycle impact assessment method based on endpoint modeling approach to derive weighting factors that represent the respondents’ value system for tradeoffs among environmental impacts. We use a modified fuzzy Technique for Order Preference by Similarity to Ideal Solution approach to evaluate technical criteria dominance in declared preferences. A statistical model of corporate behavior is also presented. The results provide the first systematic framework that accounts for environmental impact, technological challenge, and business strategy concurrently toward formulating a comprehensive national policy for materials selection in electronic products.     

Distribution and health-risk of polycyclic aromatic hydrocarbons in soils at a coking plant

Nineteen soil samples were collected in and around Songshan coking plant in Guangdong province of China and analyzed for eighteen polycyclic aromatic hydrocarbons (PAHs) by gas chromatography-mass spectrometry (GC-MS). The total concentration of PAHs ranged from 2.36 to 1146.39 mg kg(-1) dry weight, varying significantly among the sampling sites, most individual PAHs were correlated with each other. A cluster analysis was performed to examine the correlation of PAH distribution, five groups were observed with sample types in the coking plant. 2-3 ring PAHs were predominant in group I and II, while 4-5 ring PAHs showed great abundance in group III, IV and V, which contributed to the distance from the emission sources in the coking plant and the behaviors of particle-bound and gaseous PAHs. The ratios of Flu?:?(Flu + Pyr), BaA?:?(BaA + Chr), InP?:?(InP + BgP) and Ant?:?(Ant + Phen) ratios were 0.51-0.87, 0.16-0.89, 0.47-0.68 and 0.03-0.60, respectively. The total index of all studied soils was > 6, indicating that the source of the PAHs in coking plant soils were from the pyrolysis processes. Health risk assessments were carried out by dermal PAH exposure data to quantify cancer risk. The resultant lifetime exposure levels due to TEQ(BaP) desorbed onto skin for workers ranged from 2.25 × 10(-7) to 7.86 × 10(-5) mg kg(-1) per day, and the estimated cancer risks were between 8.45 × 10(-6) and 2.94 × 10(-3), indicating that the dermal exposures of PAHs to coking workers might be acceptable in most soil sites.     

Polycyclic aromatic hydrocarbons with molecular weight 302 in PM 2.5 at two industrial sites in South China

Daytime and nighttime PM(2.5) samples were collected between August 5 and 16, 2009 and between January 24 and February 4, 2010 in an industrial complex site (site A) and an electronic waste recycling site (site B) to determine the seasonal and diurnal variations of 19 individual polycyclic aromatic hydrocarbons (PAHs) with molecular weight 302 (MW302) including four highly carcinogenic dibenzopyrene (DBP) isomers dibenzo[a,l]pyrene (DBalP), dibenzo[a,e]pyrene (DBaeP), dibenzo[a,i]pyrene (DBaiP), and dibenzo[a,h]pyrene (DBahP). This is the first report on DBP isomers in air particles from South China. The total concentration of PAH MW302 isomers ranged from 1.65 to 3.60 ng m(-3) in summer and 3.82 to 9.81 ng m(-3) in winter. The strongest peaks in the chromatograms of the MW302 isomers were naphtha[2,1-a]pyrene (N21aP), dibenzo[j,l]fluoranthene (DBjlF), naphtha[1,2-b]fluoranthene (N12bF), naphtha[1,2-k]fluoranthene (N12kF) and dibenzo[a,e]fluoranthene (DBaeF), constituting 52.0 to 55.4% of the total MW302 isomers. All the MW302 isomers showed notable seasonal variations. Most of the MW302 isomers in site B showed distinctive diurnal variations with higher concentrations occurring in the night. Taking into account both concentration and potency equivalence factors (PEFs), the strongest carcinogen in the analyzed samples was DBaiP, and the ratios of sum carcinogenic potency of four highly carcinogenic DBP isomers to benzo[a]pyrene (BaP) was about 0.94 in winter to 1.89 in summer, indicating the importance of DBP isomers for the risk assessment. Health risk assessment indicated that on average, 1 in 100 000 residents in the two industrial sites may have an increased risk of cancer due to PAH exposure.     

Geochemical characteristics of inorganic sulfur in Shijing River, South China

Different inorganic sulfur species distributed in overlying water, pore water and sediment in a heavily polluted river were determined. The concentrations of S(2-) and SO(4)(2-) in the overlying water were much more than those in the pore water. This result perhaps indicates the S(2-) was mainly from discharged wastewater, not from sediment resuspension. In the sediments, acid-volatile sulfide, chromium(ii)-reducible sulfide, and elemental sulfur were determined by a modified diffusion method. The results indicate that acid-volatile sulfide was the dominant component of the reduced inorganic sulfur, making up about 62% of the total reduced inorganic sulfur.