西北某花岗岩型碱交代热液铀矿床蚀变带中重矿物的性状

花岗岩型碳酸钠质交代热液铀矿床蚀变带中的重矿物有明显的改造与叠加现象。随着矿物的解离,热液从围岩中获取了部分矿源。主要铀矿化是在热液连续活动的晚期,铀与金属硫化物共沉淀。本文就西北某花岗岩体在碳酸钠质热液作用下所发生的重矿物组合含量及主要重矿物性质的一系列变化,以及与此有关的铀的活化转移与沉淀阶段等问题进行讨论。     

Potential hyperaccumulation of Pb, Zn, Cu and Cd in endurant plants distributed in an old smeltery, northeast China

The absorption and accumulation of Pb, Zn, Cu and Cd in some endurant weed plant species that survived in an old smeltery in Liaoning, China, were systematically investigated. Potential hyperaccumulative characteristics of these species were also discussed. The results showed that metal accumulation in plants differed with species, tissues and metals. Endurant weed plants growing in this contaminated site exhibited high metal adaptability. Both the metal exclusion and detoxification tolerance strategies were involved in the species studied. Seven species for Pb and four species for Cd were satisfied for the concentration time level standard for hyperaccumulator. Considering translocation factor (TF) values, one species for Pb, seven species for Zn, two species for Cu and five species for Cd possessed the characteristic of hyperaccumulator. Particularly, Abutilon theophrasti Medic, exhibited strong accumulative ability to four heavy metals. Although enrichment coefficients of all samples were lesser than 1 and the absolute concentrations didn’t reach the standard, species mentioned above were primarily believed to be potential hyperaccumulators.     

Progress in isotope paleohydrology using lake sediment cellulose

Recent advances in sample preparation techniques and mass spectrometry have fostered more routine oxygen isotope analysis of aquatic cellulose in lake sediment cores, a proxy for lake water oxygen isotope history. These methodological developments have significantly increased the feasibility of incorporating this approach into high-resolution, multi-site, and multi-proxy studies, which are frequently necessary to answer complex hydrological, hydroecological and hydroclimatic questions requiring a paleoenvironmental perspective. Direct translation of lake sediment aquatic cellulose oxygen isotope composition into lake water oxygen isotope composition offers appreciable opportunity for quantitative paleohydrological reconstructions, as evidenced by studies conducted over the past 15 years that span Holocene and pre-historical timescales.     

An Experiment Using the High Resolution Eta and WRF Models to Forecast Heavy Precipitation over India

In the present study using the Weather Research and Forecasting (WRF) and Eta models, recent heavy rainfall events that occurred (i) over parts of Maharastra during 26 to 27 July, 2005, (ii) over coastal Tamilnadu and south coastal Andhra Pradesh during 24 to 28 October, 2005, and (iii) the tropical cyclone of 30 September to 3 October, 2004/Monsoon Depression of 2 to 5 October 2004, that developed during the withdrawal phase of the southwest monsoon season of 2004 have been investigated. Also sensitivity experiments have been conducted with the WRF model to test the impact of microphysical and cumulus parameterization schemes in capturing the extreme weather events. The results show that the WRF model with the microphysical process and cumulus parameterization schemes of Ferrier et al. and Betts-Miller-Janjic was able to capture the heavy rainfall events better than the other schemes. It is also observed that the WRF model was able to predict mesoscale rainfall more realistically in comparison to the Eta model of the same resolution.     

株州市土壤重金属污染的对应分析

株州市土壤重金属污染的主要原因是工厂排放有害气体，或是水体污染物随灌溉进入土壤。采用对应分析方法，将市区土壤重金属污染分析３种类型。靠近人业污染源附近，镉的含量及污染指数高；大部分土壤受多种重金属污染；水稻土主要表现为铅的污染。     

Heavy Metal Load of Sediments of the River Gurk (Carinthia/Austria) — Merits and Limitations of Sequential Leaching Schwermetallbelastung des Sediments der Gurk in Kärnten — Vorzüge und Einschränkungen sequentieller Löseverfahren

By means of the analysis of sediments cored in the small river Gurk (Carinthia/Austria), the input of Ag, Cd, Ce, Cr, Hg, La, Mo, Ni, V, and W from a chemical industrial plant could be detected. To estimate the actual load, and to obtain data for comparison with other sites, both unsieved fine sediments and sediments sieved to 20 μm were investigated from the same cores. Environmental mobilities of toxic heavy metals (Co, Cr, Cu, Ni, Zn) have been shown by sequential leaching following Tessier/Förstner. In the last step, HNO₃ leaches a purely geogenic fraction, which is fairly constant along the investigated river. Whereas the additional Cr from the input of the chemical plant is mainly found in the oxalate-leachable fraction, short-time-load to unpolluted sediments in the laboratory is found mainly in hydroxylamine/acetic acid. Both is due to the high affinity of Cr to Fe- and Mn-oxides. Adsorption/desorption experiments reveal that the low carbonate content of the Gurk sediments increases the importance of Fe/Mn-oxides for the sorption of Cr compared to other samples containing carbonate. The Ni-load was primarily found in weak-acid-leachable and oxalate-leachable fractions. Similarly, the oxalate-leachable fraction is dominant for adsorption of other metals and phosphorus. Other interelement relationships among the amounts leached, which are attributable partly to carbonate-, silicate-, organic or coating phases, have been found by means of factor analyses together with marker fractions for each type.     

Effects of Deicing-Salts on Heavy Metal Mobility Zum Einfluß von Streusalzen auf die Beweglichkeit von Schwermetallen

Heavy metal input into roadside soils and effects of deicing salts are often discussed as separate environmental problems. However, a relationship between salt input and heavy metal mobility has already been detected in laboratory tests. During a 2-year field study, the soil solution of a roadside soil was continuously sampled. The results of soil solution analysis not only showed a strong rise in deicing-salt related sodium, calcium and chloride concentrations, but also high zinc and cadmium values in winter and spring. Additional laboratory tests confirmed the mobilizing effects of salt solution which contained NaCl and CaCl₂. Cation exchange and the formation of chlorocomplexes are discussed as the responsible mechanisms.     

Use of Factor Analysis to Study the Distribution of Metalliferous Bauxitic Tailings in the Seabed of the Gulf of Corinth,Greece

In 1994, a detailed marine environmental survey was carried out in surface sediments of the northern flank (Antikyra Bay) and the basin floor of the Gulf of Corinth. Metalliferous tailings (red-mud slurry) of a bauxite processing plant are discharged through a pipeline at a water depth of 100 m, in the Antikyra Bay, covering an area of 16 km². The bauxitic tailings are detached from the main deposit at the outfalls, flow as turbidity currents downslope, and are redeposited on the basin floor of the Gulf of Corinth, where they cover an area of about 277 km². One hundred sediment samples, that were collected from red-mud deposits and the surrounding natural sediments, were analyzed for Ag, Al, Cd, Co, Cr, Cu, Fe, Hg, Mg, Mn, Ni, Pb, Si, Ti, V, and Zn concentrations. Statistical analysis of the heavy metals concentrations using factor analysis allowed (i) an examination of the interrelations among metals and (ii) distinguishing possible sample groups on the basis of metal concentrations in order to study the mechanisms of transport of the red mud and the degree of mixing with natural sediments. Factor 1 (Al, Cr, Ti, Fe, Co, Ni, Pb, Ag, Hg, V, Cd, and Cu) and the positive pole of Factor 2 (Cu, Ag, Cd, and Hg) are red-mud factors, reflecting different metal behaviors, which are related to processes that take place during the transport and redeposition of the red mud. The negative poles of Factors 2 and 3 and the positive pole of Factor 4 are related to natural sediment supply processes. Q-mode factor analysis identifies three distinct sediment groups located in different areas, on the base of the degree of mixing of red mud with natural sediments.     

天津地区一次局地大暴雨过程MCS传播发展机制

利用常规观测资料、卫星云图、雷达、风廓线组网资料对2017年8月8日-9日天津地区局部大暴雨天气进行分析,得到以下结论：A、B两个中尺度雨团先后影响天津,A雨团持续了4个小时,雨强相对较大；B雨团持续了3个小时,雨强相对较小；对应有两个MCS,强降水发生在TBB低值中心偏向温度梯度最大的区域；降水回波的移动路径和强度特征存在差异,A雨团回波为自西北向东南方向移动的带状的高质心降水回波；B雨团回波自西南向东北方向移动,为低质心降水回波带状回波,高质心降水回波雨强高于低质心降水回波。新型探测资料有助于分析中尺度影响系统,判断对流系统的移动方向。用风廓线组网资料对比两个阶段降水的中尺度系统,A雨团为上冷下暖的高低空配置,B雨团降水出现在整层西南气流中,引导风的不同,导致回波的移动方向、天气剧烈程度的不同；变压梯度、温度梯度等环境因素对判断局地对流暴雨发生的环境条件有一定指示性。     

一次滇西南秋季暴雨的中尺度分析与诊断

应用大尺度物理量场诊断分析和中尺度带通滤波处理技术,对2001年10月25日发生在云南西南部的一次暴雨过程机制进行了分析。结果表明,在副热带高压(下称副高)外围大尺度西南气流环境场中,中尺度系统是此次暴雨产生的直接原因;大尺度环境场为暴雨的发生提供了充沛的水汽来源,而中尺度系统则在水汽的强烈辐合、向上输送,使对流层中下层达到准饱和状态扮演了十分重要的角色。