7 research outputs found
Size Distribution of Particle and Polycyclic Aromatic Hydrocarbons in Particle Emissions from Simulated Emission Sources
采用再悬浮箱模拟得到不同粒径的烹调油烟、生物质和塑料燃烧烟尘、汽车尾气和发电机烟气等颗粒,并用gC/MS对不同粒径颗粒中18种多环芳烃(PAHS)进行了分析.结果表明,烹调油烟中颗粒物存在0.44~1.0μM和2.5~10μM两个峰值,稻草和木材燃烧排放烟尘只有0.44~1.0μM一个峰值,塑料燃烧排放烟尘的峰值不明显,汽车尾气尘因含有大量的水汽导致其粒径峰值出现在2.5~10μM,而发电机排放的烟尘约93%集中在≤2.5μM的粒径范围.烹调油烟和汽车尾气尘中低环数PAHS在2.5~10μM范围内的峰值明显;随环数增加,0.44~1.0μM范围内的峰值变得明显;不同排放源亚微米颗粒中单一PAH占全部颗粒态中该PAH的比例都呈现随分子量的增大而增大的趋势.烹调油烟和燃烧排放颗粒中PAHS的组成以菲占主导,但汽车尾气和发电机烟尘中含量最高的PAHS分别是萘和苯并[g,H,I]苝.来源特征比值的比较显示,烹调油烟与生物质燃烧颗粒中PAHS的源特征较为接近,但两者都不同于汽车尾气和发电机烟尘.Particles from cooking lampblack,biomass and plastics burning smoke,gasoline vehicular exhausts and gasoline generator exhausts were prepared in a resuspension test chamber and collected using a cascade MOUDI impactor.A total of 18 polycyclic aromatic hydrocarbons( PAHs) associated with particles were analyzed by GC-MS.The results showed that there were two peaks in the range of 0.44-1.0 μm and 2.5-10 μm for cooking lampblack,and only one peak in the range of 0.44-1.0 μm for straw and wood burning smoke.But there were no clear peak for plastics burning smoke.The peak for gasoline vehicular exhausts was found in the range of 2.5-10 μm due to the influence of water vapor associated with particles,while the particles from gasoline generator exhausts were mainly in the range of ≤2.5 μm( accounting for 93% of the total mass).The peak in 2.5-10 μm was clear for cooking lampblack and gasoline vehicular exhausts.The peak in the range of 0.44-1.0 μm became more and more apparent with the increase of PAHs molecular weight.The fraction of PAH on particles less than 1.0 μm to that on the total particles increased along with PAH's molecular weight.Phenanthrene was the dominant compound for cooking lampblack and combustion smoke,while gasoline vehicular exhausts and generator exhausts were characterized with significantly high levels of naphthalene and benzo[g,h,i]perylene, respectively.The distribution of source characteristic ratios indicated that PAHs from cooking lampblack and biomass burning were close and they were different from those of vehicular exhausts and generator exhausts.国家自然科学基金项目(40971257;41171365); 环境保护公益性行业科研专项(201009004
新疆主要河流水文极值变化趋势
水文极值是工程水文计算的基础资料,实测样本资料的变化直接影响水文设计值。基于1956-2006年的实测洪峰、洪量、年最小流量、最枯月径流量等资料,分析了各水文要素的变化及其趋势。结果表明:20世纪80年代中期以来超标准洪峰、洪量的频次增加,大多数河流洪水峰、量都呈增大变化趋势,说明新疆洪水又进入活跃期,在工程水文设计洪水计算中要应尽可能搜集和利用近期暴雨和洪水资料,在洪水系列中增加更多大洪水信息,提高设计洪水计算成果的稳定性。年最小流量和最枯月径流量是维持河流生命和河道两岸自然生态的基础流量,基流量增大有利于对生态补给、水利发电,水库蓄水,径流年内分配趋于均匀有利于水量年内调节。但在枯水径流分析计算中应充分重视不同年份最枯水量出现时间有明显推迟的迹象
利用遥感技术对新疆耕地等级综合评价与分析
该研究是应用遥感技术从不同波段合成的卫星图像所反映的耕地资源影像特征中,分析提取影像耕地的相关信息,并利用GIS、ARC/View软件平台,建立了相关的数据库,采用的技术成熟、科学、适用。针对新疆耕地资源保护和利用中规模、类型和质量的动态监测的技术难题,首次在新疆建立了GIS软件支持下耕地资源本底信息库及动态管理系统,为新疆土地资源的科学化管理和动态跟踪监测,提供了科学、先进的管理平台;根据新疆的自然地理特征和农业发展状况,从科学性和可操作性的角度,通过分析确定新疆耕地主要障碍因素及影响程度,建立了适合于新疆耕地特点的TM遥感解译模式,为今后新疆耕地遥感调查工作打下了良好的基础
Emission of Fine Particles and Fine Particle-bound Polycycli Aromatic Hydrocarbons from Simulated Cooking Fume
采用在再悬浮箱内进行炒菜模拟,采集获得粒径小于2.5μm的细颗粒(PM2.5),并对PM2.5中的18种多环芳烃(PAHs)进行了分析.结果表明,不同食材组合下烹调油烟中PM2.5排放因子的组间差异高于PAHs,排放PAHs的组成以菲占主导(占总量37%~49%),其次为萘和荧蒽(两者合计占总量16%~21%).以食用油的人均年消耗量17kg为基准,计算人均餐饮活动排放PM2.5及PAHs分别为1.47kg和32.13mg.烹调油烟中PAHs的来源特征比值(茚并[1,2,3-cd]芘/(苯并[ghi]苝+茚并[1,2,3-cd]芘),荧蒽/(芘+荧蒽))接近木材和煤燃烧的比值范围,有别于汽车尾气.采用过量终生癌症风险方法估算得到家庭主妇因暴露于烹调油烟而患癌症的风险为6.15×10-6。Abstract:Fine particles(PM2.5),from cooking fumes,were prepared using a resuspension chamber and then were analyzed for 18 polycyclic aromatic hydrocarbons(PAHs).The results showed that the differences of PM2.5emission rate between different tests were greater than that of PAHs.The profiles of PAHs were dominated by phenanthrene(account for 37%-49%)followed by naphthalene and fluoranthrene(both together account for 16%-21%).Annual emission amount of PM2.5and PAHs per capita were estimated to be 1.47kg and 32.13mg,respectively,based on the annual consumption of 17kg plant oil in China.The distributions ofsource characteristics ratios of PAHs(indeo[1,2,3-cd]pyrene/(benzo[ghi]perylene+indeo[1,2,3-cd]pyrene),fluoranthene/(pyrene +fluoranthene))from simulated cooking fumes were close to that of grass/wood/coal combustion,but differed from that of vehicular exhausts.According to the oral cancer slope factor of benzo[a]pyrene,the average excess lifetime cancer risk of housewives was estimated to be 6.15×10-6.国家自然科学基金项目(40971257,41171365);公益性行业科研专项(201009004);厦门大学“大学生创新训练计划”项
35MeV/u~(36)Ar+~(112,124)Sn反应中中等质量碎片关联函数的入射道依赖
测量了35MeV/u36Ar+112,124Sn反应中小角关联出射的中等质量碎片(IMF)约化速度关联函数.结果表明36Ar+124Sn反应系统中的约化速度关联函数在小约化速度处的反关联程度比36Ar+112Sn反应系统中的强,表现出明显的入射道依赖性.考察出射粒子对的单核子总动量时,发现这种差异主要来自于高动量粒子对的贡献.用三体弹道理论模型MENEKA分别计算了两个系统的IMF发射时标,在36Ar+112Sn反应系统中约为150fm/c,而在36Ar+124Sn反应系统中,约为120fm/c.同位旋相关的量子分子动力学计算表明,36Ar+124Sn系统中IMF的发射时间谱比36Ar+112Sn系统略有前移,相应地,其中心密度从最高点随时间的下降亦比36Ar+112Sn系统略快
塔里木河流域适应气候变化的水热调节技术研究
本成果来自于国家科技支撑计划项目“全球环境变化应对技术研究与示范”之06课题“典型脆弱区域气候变化适应技术示范”之04专题“西北生态脆弱区适应气候变化技术示范”(2007BAC03A06-04)。课题于2007年11月立项,于2010年11月30日通过国家科技部的验收。针对塔里木河流域气候变化影响关键科学问题,建立了山区水库—平原水库联合调节、绿洲地表水—地下水联合开发、膜下滴灌的作物立体种植模式、下游生态恢复与洪水(融雪水)沙漠造林生物固碳等大型原位可控的技术示范基地;构建了区域气候变化优势适应技术筛选与评估流程,集成了塔里木河流域气候变化适应技术行动实施方案与功能区划图,首次提出了塔里木河..