辽宁小塔子沟金矿床矿脉地球化学特征及找矿标志

在小塔子沟金矿,Ba、As、Sb、Hg、Pb为前缘元素,Mo、Co、Ni为尾晕元素,Bi、Ag、Cu、Zn为主要伴生元素.随着矿脉深度的加深,Na₂O逐渐变大,TFeO逐渐变小,利用根据这种关系拟合成的线性方程可预测矿脉的深度.在有规模的矿脉中,石英流体包裹体的均一温度变化区间比较宽(160～400 ℃),流体的盐度变化范围大(0～9%);而在规模较小的矿脉中,温度比较高(280～400 ℃),盐度比较低(<5%).在矿脉的深部,成矿流体的温度比较高,盐度比较低,包裹体数量明显减少.根据上述找矿标志,1号脉19中段以下的深部出现有规模工业矿体的可能性不太大;2号脉的成矿前景可能好于5、6号脉;距北大山二长花岗岩南1～3 km范围是寻找新的平行富矿体的最有利地段.     

河南桐柏破山银矿床原生地球化学异常模式

破山银矿是典型的变质碎屑岩型层控特大型银矿床,位于南阳、吴城断陷盆地之间,它经历了长期、复杂的地质发展历史,其成生、演化具多阶段性。成矿作用是在沉积、成岩、变质的基础上,经后期热液作用叠加,主要成矿作用为加里东晚期地下热水溶滤富集。成矿物质来自上元古界歪头山组上、中部,主要成矿元素具有明显的分带现象——上部富银、下部富锌。矿体周围紧密伴有Ag、Pb、Zn、Cd、As、Cu、Mn、(Sb)等元素组合异常。在对矿床原生地球化学异常特征总结的基础上,建立原生地球化学异常模式和找矿评价的地球化学标志。     

青海德尔尼岩浆热液型铜矿区域地球化学异常特征和找矿标志

以我国青海德尔尼岩浆热液型铜矿床为目标,开展矿床区域地球化学特征和区域地球化学异常特征研究,在综合分析的基础上,结合地质条件提出了地质地球化学找矿标志。     

伊通河水环境容量与污染防治对策的研究

长春市唯一过境河流－伊通河是市区内工业废水和生活污水的主要受纳水体。依据各河段的区位、水力、污染、使用特征对伊通河环境进行功能区划分,然后按各功能区不同的控制标准计算了环境容量、污水允许排放量和污染物允许排放浓度,并与整体控制时的相应指标进行比较,最后提出分区控制的优越性和必要性及恢复伊通河水环境质量的减压增容措施,以确保地区的经济建设与环境保护协调发展。     

夏季南极普里兹湾碳的生物地球化学循环Ⅱ:POC的分布特征

在中国第 1 5次南极考察期间对普里兹湾的颗粒有机碳 (POC)进行了研究。结果表明 :夏季普里兹湾 POC表层含量在 94.2 0 - 1 1 2 4 .0 0μg/L ,平均 2 79.1 1μg/L ,POC含量由湾内向湾外递减。湾内平均含量 5 2 7.1 4μg/L,湾外平均含量 1 71 .72 μg/L,湾内 POC含量远远大于湾外。断面分布表明水体上层 POC含量高于底层含量 ,在 1 0 0 m附近含量达到最低 ,且变化显著。 POC与叶绿素 a的高度相关性 (r=0 .889,n=91 )表明普里兹湾 POC主要由 POCB组成即主要来自于浮游植物的贡献。 POC/chl a值为 1 1 0 .3 3与 Ross海相近 ,但高于太平洋等海域。 POC与DIN、PO4 3 - 之间均呈现良好的负相关 ,相关系数分别为 - 0 .6 0 7、- 0 .486 (n=86 )。     

Nutrient budget of a montane evergreen broad‐leaved forest at Ailao Mountain National Nature Reserve,Yunnan, southwest China

Hydrological fluxes and associated nutrient budget were studied during a 2 year period (1998–99) in a montane moist evergreen broad‐leaved forest at Ailao Mountain, Yunnan. Water samples of rainfall, throughfall, and stemflow, and of surface runoff, soil water, and stream flow were collected bimonthly to determine the concentration and fluxes of nutrients. Soil budgets were determined from the difference between precipitation input (including nutrient leaching from canopy) and output via runoff and drainage. The forest was characterized by low canopy interception and surface runoff, and high percolation and stream flow. Concentrations of nutrients were increased in throughfall and stemflow compared with precipitation. Surface runoff and drainage water had higher nutrient concentrations than precipitation and stream water. Total nitrogen and NH₄⁺‐N concentrations were higher in soil water than stream water, whereas K⁺, Ca²⁺, and Mg²⁺ concentrations were lower in the former than the latter. Annual nutrient fluxes decreased with soil depth following the pattern of water flux. Annual losses of most nutrient elements via stream flow were less than the corresponding inputs via throughfall and stemflow, except for calcium, for which solute loss was greater than the inputs via precipitation. Leaching losses of that element may be compensated by weathering. Losses of nitrogen, phosphorus, potassium, magnesium, sodium, and sulphur could be replaced through atmospheric inputs. Copyright © 2002 John Wiley & Sons, Ltd.     

湖泊营养分类的初步研究

本文应用模糊综合评判理论和方法,把正常湖泊分为五种营养类型,选用总氮、总磷、硅盐、浮游植物和浮游动物五个参数评介湖泊营养化程度。对湖泊营养类型分类进行了开拓性研究。     

The convergence domain of the Laplacian expansion of the disturbing function

A computer-assisted reformulation of Sundman's determination of the the domain of absolute convergence of the Laplacian expansion fo the disturbing function is given. Sundman's results are extended to the cases of librating perihelions and a convergence criterion is established for the case of mutually inclined orbits.     

A one‐year study of the Rostherne Mere ecosystem: seasonal dynamics of water chemistry,plankton, internal nutrient release,and implications for long‐term trophic status and overall functioning of the lake

A study of Rostherne Mere (Cheshire, UK) was undertaken to reveal relationships among various ecosystem components and assess the progress in lake recovery following sewage diversion. An intensive monitoring programme included measurements of dissolved oxygen, T, pH, electric conductivity, K, Mg, Ca, Si, N and P species, Secchi depth, suspended solids, chlorophyll‐a, phyto‐ and zooplankton counts. Recorded changes and the results of correlation analysis broadly confirmed to the classic limnoecological theory and allowed detailed interpretation of the dynamics observed. The Si level was used to estimate the amount of diatom detritus produced in spring. Chemical profiles were used to estimate the amount of nutrients accumulated in the hypolimnion during the stratified period. These estimates were compared with simulations made using the model of exponential decay, which showed a good performance in the case of Si but considerable underestimation in the case of P. The differences between the values simulated by the model and estimates based on field observations resulted from the additional P release from the sediments. This release could have been stimulated by a combination of factors, including the development of anoxic layers on the sediment–water interface and Si‐induced desorption from Fe, Al and Mn oxides. Internal P loading during the stratified period was thus estimated at about 4–9 g/m², suggesting that rapid changes in the lake's trophic status are at present unlikely. Certain aspects of this work (including interpretation of interrelationships between ecosystem components, estimation of the decomposition constant, analysis of factors controlling nutrient accumulation in the hypolimnion, and a low‐cost method to estimate internal P release) may be useful for studies of other aquatic systems and have, therefore, general limnological applicability. Copyright © 2001 John Wiley & Sons, Ltd.