Preliminary health risk assessment for polybrominated diphenyl ethers and polybrominated dibenzo-p-dioxins/furans in seafood from Guangzhou and Zhoushan, China

Dietary intake is one of the important routes of human exposure to brominated flame retardants (BFRs) such as polybrominated diphenyl ethers (PBDEs). The use of PBDEs may also result in exposure to polybrominated dibenzo-p-dioxins and dibenzofurans (PBDDs/DFs), as these compounds are impurities in technical mixtures of BFRs and can also be formed unintentionally by the same processes that generate chlorinated dioxins. This study determined the concentrations of polybrominated compounds in common seafood in Guangzhou and Zhoushan, and assessed the health risks of these chemicals via consumption of contaminated seafood. Seafood samples (fish, bivalves, shrimp, crab, and cephalopods) purchased from local markets in 2003 and 2004 were analyzed for PBDEs and PBDDs/DFs. The highest concentration of total PBDEs (46.3 ng g(-1) lipid wt.) was detected in fish from Guangzhou, in which BDEs 47 and 209 were the two predominant congeners. The total daily intakes of PBDEs, PBDDs, and PBDFs were, 946, 6.39, and 6.54 pg kg(-1) body weight (bw) in Guangzhou, and 489, 4.99, and 7.65 pg kg(-1) bw in Zhoushan, respectively. The hazard ratios for PBDDs and PBDFs were both greater than unity, indicating that these compounds may pose some health risks to the local population.     

珠江三角洲两工业区土壤环境磁学初步研究

对珠江三角洲东莞石龙、顺德容奇—桂洲两工业区的土壤磁性进行初步研究,获得两地区6个柱样及48个表层样品的磁化率（X）和天然剩余磁化强度（NRM）的结果,石龙地区的X,NRM的垂直变化平均值分别为10．86×10－6SI和6．73×10-6A·m－1,顺德容桂地区X,NRM的垂直变化平均值分别为96．84×10－6SI和31．49×10－6A·m－1,表层样容桂地区X和NRM值大于石龙地区,表明两地区土壤的磁载体存在明显的差异,磁记录大致能反映现代环境的信息。     

直读式流速仪升级的使用维修对策

通过对比、分析国产ＺＳＸ系列直读式流速仪Ⅰ和Ⅱ型显示器的不同之处,介绍它们的兼容方法,使之因仪器升级而被淘汰的流速仪资源被充分地利用。     

A study of pH effect on protease activity of larval and young porgy

ＡｓｔｕｄｙｏｆｐＨｅｆｆｅｃｔｏｎｐｒｏｔｅａｓｅａｃｔｉｖｉｔｙｏｆｌａｒｖａｌａｎｄｙｏｕｎｇｐｏｒｇｙＩＮＴＲＯＤＵＣＴＩＯＮＰｏｒｇｙ（Ｐａｒｇｒｏｓｏｍｕｓｍａｊｏｒ）ｉｓａｓｐｅｃｉｅｓｏｆｉｍｐｏｒｔａｎｔｃｏｍｍｅｒｃｉａｌｆｉｓｈ...     

Metasomatic origin of some of the eclogite-bearing carbonate rocks in the Dabie mountain region, China

Carbonate rocks are one of the major hosts to eclogite in the Mt. Dabie region. Eclogite bodies enclosed in the carbonate rocks occur mostly as knobs, ovoids and lenses measuring centimeters to tens of centimeters in size. The bodies have been intensely carbonatized and usually have transitional contacts with their carbonate hosts. The carbonate rocks have abundant relics of eclogite minerals and their retrogressive derivatives. The REE patterns of the carbonate rocks are characterized by the absence of negative Ce anomaly. These features suggest that a considerable portion of the eclogite-bearing carbonate rocks in the Mt. Dabie region was produced by carbonatization of eclogites and their retrogressive derivatives. These carbonate rocks suffered deformation and recrystallization after their formation. This research project was financially supported by the Ministry of Geology and Mineral Resources (Project No. 9501102-04-1).     

中国主要类型锑矿床硫同位素组成及地球化学特征

中国主要类型锑矿床的硫同位素组成范围变化很大,锑矿床中各种矿物（辉锑矿、黄铁矿、闪锌矿、雄黄、方铅矿、重晶石、毒砂、辰砂、脆硫锑铅矿）的δ３４Ｓ值从－３２．７‰变化到＋３４．８‰,极差值高达６７．５‰。各类锑矿床中矿物的硫同位素组成变化各异,说明锑矿床成因较复杂,硫的来源不仅有海水中沉淀的硫酸盐硫,而且还有生物、细菌形式的还原硫和深源硫（岩浆作用、喷流作用等）,从而形成不同类型或成因复杂的锑矿床     

磁黄铁矿在纳米碳管生长中的作用

本文采用天然磁黄铁矿矿物－六方磁黄铁矿和单斜磁黄铁矿分别作催化剂,引入电弧法生长纳米碳管,发现二者具有截然不同的催化效果。在此基础上,探讨了在合成纳米碳管实验中磁黄铁矿的催化作用及催化机理。     

灵台红粘土和黄土-古土壤序列的地球化学演化

沉积物的化学成分无疑取决于来源物质的成分和沉积后的化学作用。对来自于甘肃灵台7MaBP以来风成沉积序列的红粘土、黄土和古土壤样品的化学分析表明,风成沉积物化学成分的演化主要由沉积前所经历的各种地表作用(尤其是风化作用)所决定,当地成壤作用对化学成分的影响叠加在10⁶a演化趋势上5反映风化程度的化学指标Na／Al值和Fe²⁺／Fe³⁺值总体均呈逐步增加的趋势,基本一致于上新世以来全球气候变化的趋势,这可能与青藏高原隆升和北半球冰盖发育加速粉尘物质源区侵蚀同时降低化学风化程度有关。     

遥感模拟图像应用于不同传感器光谱性能分析

研究利用高光谱成像数据,用数字的方法定量模拟了SPOT－HRV、CBERS-CCD、Landsat5-TM和NOAA14-AVHRR类似波段的空中表面反射率及地面光谱反射率图像,并利用这些图像对上述传感器相应波段的光谱响应、大气影响特性用基于反射率和基于归一化植被指数（NDVI）的方法进行了定量的比较分析。研究表明,由于传感器类似波段的光谱响应不同,因而由其计算的反射率和NDVI之间均存在明显差异,这种差异是大气改正所无法完全消除的。多传感器定量分析时需要进行相应的辐射改正。     

中国大陆中尺度对流复合体的环境场演变特征

采用合成分析方法,将中国大陆中尺度对流复合体的生命史划分为７ 个子阶段,详细探讨ＭＣＣ演变过程中的能量生消特征。结果表明：在ＭＣＣ的持续阶段,５００ｈＰａ 以下始终有深厚不稳定层存在,不稳定度渐渐减小,水汽、热量从西南和偏南方进入ＭＣＣ,最大通量值出现在９００～５００ ｈＰａ 高度。高、低、中空环流配合对ＭＣＣ的启动和发展有重要意义。