过冷雨水低含量条件下冰雹形成和增长机制及其催化效果的数值模拟

利用中国科学院大气物理研究所开发的三维全弹性冰雹云模式,对美国对流降水协作试验（CCOPE）期间观测的1981年8月1日雹云进行模拟,讨论在过冷雨水低含量条件下冰雹形成和增长机制及其碘化银催化效果。结果表明:(1) 自然云的模拟与观测事实一致,如最大上升气流速度、云顶高度、流场结构以及雹胚组成等。(2) 雹胚以霰为主,霰主要来自冰雪晶与过冷小水滴的碰冻,其次来自雪的积聚转化;霰、冻滴和冰雹在形成后主要靠碰并过冷云水增长。(3)人工催化试验表明,碘化银主要以凝华核（包括凝结－冻结）的作用产生大量的人工冰晶,加速了过冷水向冰晶的转化,过冷云水因而大量减少;催化后霰和冻滴的数浓度增大,对过冷云水的竞争增强,其平均尺度减小导致转化成雹的数量减少;冰雹碰冻过冷云水的增长在催化后也被削弱,导致冰雹总质量进一步减少。此外,催化后降雨量也显著减少。     

The dissolved iodate and iodide distribution in the South Atlantic from the Weddell Sea to Brazil

Iodide and iodate concentrations are reported and discussed for the WOCE A23 transect from the Weddell Sea north to about 25°S. Iodide concentrations are very low in the surface waters of the Weddell Sea (20 nM) and increase steadily northwards to about 100 nM in the surface waters of the south Atlantic gyre. In deep waters iodide concentrations are low but detectable at 0.5–2 nM. There is no detectable total iodine depletion in the surface waters south of the polar front although there is a small depletion evident north of the front. The results are discussed in terms of the hydrography, nutrient concentrations and phytoplankton activity along the transect. In particular, a systematic change in the relationship between iodide and nitrate along the transect is discussed.     

离子色谱法测定碘在地甲病环境地质调研中的应用

收集了安徽省某地区地甲病流行患者的血、尿、发样，病区的饮水样、谷物、蔬菜样和环境地质样共计６９９个，同时收集了该地非病区水样和环境地质样２８２个。水样直接进样，其它样品经湿法分解后，用离子色谱法测定其中的碘和溴的含量。统计分析表明，病区地甲病患病率与饮水中碘的含量密切相关，也与环境地质如地貌、地质构造及水文地球化学等条件密切相关。碘含量低的石灰岩地区，地甲病患病率高。     

在线液-液萃取微型万用分相器的设计和应用 Ⅱ.流动注射溶剂萃取分光光度法测定微量碘的分析性能

设计了一种实用的玻璃重力分相器及相应的萃取流路系统,用于在线萃取分光光度测定微量碘,萃取时ｖ水∶ｖ有机＝３０∶１,线性范围在０～３０００ｍｇ／ＬＩ－效果良好。检出限为７０μｇ／ＬＩ－,测定１ｍｇ／ＬＩ－的精密度（ＲＳＤ,ｎ＝７）为２２％,测定频率为２５／ｈ。方法用于市售海带中Ｉ－的测定,加标回收率为９８％。     

Stepwise chemical degradation of immature S-rich kerogens from Vena del Gesso (Italy)

Stepwise chemical degradation involving cleavage of ester bonds (KOH/MeOH), sulfide and remaining ester bonds (Li/EtNH₂), ether bonds (HI/LiAlH₄) and sub-units linked to aromatic moieties (RuO₄) has been carried out on the kerogens of two immature sulfur-rich marls (IV-1.4 and 1.8, TOC ca. 1.5%) from evaporitic cycle IV of the Gesosso-solfifera Formation (Messinian, Vena del Gesso, Italy). Up to 80% of the organic matter was converted to solvent-soluble material, with the greatest proportion released by Li/EtNH₂. The majority by far of the extracts comprises polar macromolecular material which is thought to correspond to high molecular weight sub-units of the kerogen. Quantification of the small amounts (<1%) of the released GC-amenable components indicates that diagenetic sulfurization was more important in the case of kerogen IV-1.4 but that the extent of oxygen sequestration was similar in both cases; the distributions of biomarkers released by ether cleavage of the desulfurized residue and polar fraction showed differences which reveal heterogeneity in the building blocks making up different macromolecular fractions.     

The role of bromide and iodide ions in the salinization mapping of the aquifer of Glafkos River basin (northwest Achaia,Greece)

Seawater intrusion causes many problems for groundwater quality, whereas natural remediation is time consuming. However, in cases where groundwater replenishment is feasible, groundwater quality remediation is possible and rapid. The alluvial aquifer in the lowland of the Glafkos River basin, which extends south of Patras city, was for over 30 years the major water source supplying the broader area. Groundwater quality has been degraded due to seawater intrusion, caused by overpumping and generally by inappropriate groundwater management. During the last decade, groundwater quality has been remedied due to diminished groundwater abstractions. The remediation rate was further higher because of rapid discharge of the brackish groundwater, through wells with freely flowing water in the coastal area, where, however, groundwater quality remains low. This paper deals with the hydrogeochemical processes that take place in the area. It is ascertained that ion exchange and mineral dilution processes are dominant. The ion relations between chloride, bromide and iodide, as well as the distribution maps of their concentrations, were used to determine the spatial distribution of the seawater intrusion front. In the lower part of the area in a distance from 1000 and 1500 m from the coast, the rBr^?/rCl^? ratio showed low values (<2·5 × 10^?3) similar to those of seawater. The rI^?/rCl^? ratio also presented low values (<7 × 10^?5), with the lowest one (2·7 × 10^?5) detected along the coastline. In the upper part of the area, a gradual change of those ratios was observed upstream, until they receive values similar to those of the surface waters of Glafkos River. Copyright © 2007 John Wiley & Sons, Ltd.     

层状云系催化增雨的中尺度模拟研究

利用PSU/NCAR中尺度模式MM5研究层状云碘化银催化后的区域外效应.在MM5中双参数显式云物理方案基础上,采用显式方法加入碘化银粒子的成核机制,建立碘化银粒子比含水量和数浓度预报方程.通过增加催化过程的程序模块,建立起一个中尺度人工催化系统.采用三重嵌套到3.3 km格距模拟了一次层状云系大范围降水,此个例-5℃到-10℃上碘化银催化试验结果表明碘化银在高空风的作用下向下风方输送并影响云内的微物理过程,碘化银持续作用时间为3h.大多数碘化银主要起凝华核作用,催化后冰晶增加主要靠凝华过程.催化后3h内在下风方区域80 km到240 km有10％～30％的增雨,出现催化区域外效应.