Comparison of the Concentrations of Chemical Components in Cloudwater Samples Collected during Four Different Field Campaigns

In this study, the results of four different field experiments concerning the speciation of iron and the concentrations of some other chemical compounds in cloudwater samples are compared to one-another. Hydrogen peroxide concentrations were higher during campaigns, conducted at sites not much influenced by anthropogenic emissions as compared to those conducted at more polluted areas. In contrast, percentages of S(IV) in the cloudwater were lowest at the rural sites and highest at the sites polluted by human activities, indicating a consumption of hydrogen peroxide in the oxidation reaction with S(IV). The concentration of dissolved iron was observed to correlate with the percentage of S(IV), which may be an essential point for the reductive dissolution of oxidic iron compounds of the aerosol particles. As far as the speciation of the dissolved iron is concerned, it became obvious that the percentage of Fe(III) is anticorrelated to the concentration of dissolved iron. This clearly shows the important effect of the chemical and/or photo reductive ways of dissolving the iron(III)-compounds from the aerosol particles. However, a correlation between the pH-value and hydrogen peroxide was observed.     

Distribution of CO_2 in Soil Air Affected by Vegetation in the Shilin National Park

This paper studies the CO2 distribution of soil atmosphere in the Shilin National Park. The measurement sites were chosen according to different topographic features and different vegetations. Seven measurement sites on 3 cross sections were chosen to pass through 3 karstic depressions or on the slopes of depressions. All measurement results show soils with pH values lower than 7.0 (from 5.4 to 6.6). There are 2 cases for the pH values of soil in different topographic features: the pH values of 2 profiles on the ridges or upper slopes of depressions are lower than those in the depressions; and the pH values of 2 soil profiles on the slopes of depressions are higher than those in the depressions. Most samples show relatively low humidity and CO2 contents on the ridges or slopes of depressions compared with soil profiles in the depressions. High CO2 contents occur at depths from -40 to -80 cm and high and dense grassland shows high CO2 contents in the soil atmosphere. Grass roots may grow and are distribu     

云南保山西庄河流域森林土壤磷吸附特性

本实验测定了云南省保山地区西庄河流域几种森林土壤对磷的等温吸附。实验结果表明，供试土壤对磷的吸附很的拟合了Langmuir等温吸附曲线。土壤母质对磷的吸附影响很大，磷吸附量依次是页岩＞石灰岩＞砂岩。土壤中铁、铝含量是影响磷吸附量遥最重要和最直接的因素，其它土壤特性也通过影响铁、铝的含量或者铁铝氧化物的活性而间接影响土壤的磷吸附量。相关分析表明，供试土壤磷饱和吸附量与活性Fe^3 、Al^3 、全氧、有机质含量分别呈正相关，其相关系数分别是0．6215、0．6853、0．6855和0．6819；而与土壤pH、Ca62 含量、交换性盐基离子含量和直离子饱和度呈负相关，其相关系分别是－0．7366、－0．6802、－0．6383和－0．8730，都达到了1％的显著水平。     

OBSERVATION ON CHEMICAL COMPOSITION OF SUPERCOOLED CLOUD AND SNOW

The rime ice samples of seven cold-cloud events,including the snow samples of two events,were col-lected at Huangshan Mountain Summit (1840m in elevation) in the January of 1986 and 1987.The resultsof analyses of the chemical composition of the rime ice and the falling snow for the events showed that thecloud water under the prevailing wind of SW,W and NW had a less pH than 5.6 while the snow and the localclouds had a larger pH than 7.0.SO_4~(2-) was the dominant ion that influenced the cold-cloud events.The ma-ximum value of pH and the minimum value of [SO_4~(2-)] appeared at the middle part of the cold-clouds.Compar-ed with the cold-cloud water,the snow had a characteristic of larger pH and lower ion concentrations.Thevariation of the ion concentrations in precipitation may be partially due to higher percentage of the solid pre-cipitation.     

伊犁盆地南缘侏罗系沉积微相及铀矿控矿条件研究

伊犁盆地是一个中生代陆相盆地，其南缘下－中侏罗统含煤地层十分发育。水西沟群划分为八道湾组、三工河组和西山窑组，沉积相分属于冲积扇相、三角洲相和湖泊相。可地浸砂岩型铀矿主要赋存于冲积扇扇中辫状河道微相和三角洲平原分流河道及泥炭沼泽微相。其铀矿床的主要控制因素是：盆地基底及周边地层含铀性；盆地周边构造发育条件；岩相古地理；沉积微相；成岩作用；地下水作用和氧化－还原地球化学分带。     

Non-destructive assessing and monitoring of populations of Isoetes lacustris L

Extensive studies of Isoetes lacustris, performed throughout Europe, resulted in regressions between the number of leaves per rosette and (1) the number of spores per megasporangium, (2) length of seasonal growth, (3) Secchi depth and (4) water colour plus a relationship between pH and the number of spores per megasporangium. The evaluation of Isoetes populations requires measurements of the lake data Secchi depth, water colour, pH and conductivity, the establishment of climate data and leaf counts on 20–30 plants with the aid of SCUBA. The method may be applied to lakes in a range of situations, varying between lowland and highland, and between temperate and subarctic climate regions. The regressions are displayed graphically. The actual mean leaf number and corresponding megaspore number are compared with the numbers referred to in the environmental data. Consistent values point to the parameters which influence growth and vitality of the quillwort and to what extent, in a particular lake. Examples of evaluation and monitoring are given.     

Spatial dynamics of soil salinity under arid and semi-arid conditions: geological and environmental implications

Salinity is a highly important problem in arid and semi-arid regions. Consequently, the analysis of soil salinity plays a crucial role in environmental sciences. Environmental variables show spatial variability and statistical tools able to analyze and describe the spatial dependence and quantify the scale and intensity of the spatial variation are needed. Moreover, the spatial prediction has special importance for agricultural transformation of the land or for environmental restoration (selection of the most appropriate species adapted to soil salinity). In this paper we propose a methodological framework based on geostatistics to model the spatial dynamics of soil salinity measurements to further analyze the case of a region in southeastern Spain.     

Distribution and Autecology of Chrysophyte Cysts from High Arctic Svalbard Lakes: Preliminary Evidence of Recent Environmental Change

Chrysophycean stomatocyst assemblages were analysed from the sediments of 17 lakes and ponds from Svalbard as one component of a multi-proxy investigation of recent environmental change in the high Arctic. Sediment cores and water chemistry were collected from each of the study lakes, and chrysophyte stomatocysts were investigated from the top 0.25 cm of sediment (present-day) and bottom (i.e., bottom of short sediment core, pre-industrial) sediment samples. This study represents the first undertaking of chrysophyte cyst morphology and distribution on Svalbard. A total of 153 cyst morphotypes were described with light microscopy and/or scanning electron microscopy, of which 21 are new forms. Canonical correspondence analysis indicates that the present-day distribution of cysts is significantly related to pH (p= 0.02), altitude (p= 0.02), and Na⁺ (p= 0.04). Marked shifts in chrysophyte cyst assemblages were recorded between the top and bottom sediment samples of most lakes. A recent study has demonstrated that Svalbard lakes receive atmospheric contaminants from both local and remote sources. The observed assemblage shifts may be the result of the combined effects of these point sources and long-range pollutants, or the effects of recent climate change, or both.     

Dependence of reaction rate of pyrite oxidation on temperature, pH and oxidant concentration

Pyrite is a common sulfide mineral, particularly abundant in mining waste. It is a focus of mine envi-ronmental concern because the oxidation of exposed pyrite may lead to acid drainage and poisonous mate-rials (like As and heavy metals) release. In the United States, approximately $1000000 per day is spent in alleviating acid mine drainage[1], while the Canadian mining community has environmental liabilities that exceed $2 billion for disposal, management, and rec-lamation of mine waste[2]. …