大厂矿区尾矿稀散资源分布规律与潜力评价研究     

皮桥辉 《地质与勘探》2014,50(2):291-302

许多矿山开采和选矿排放的尾砂中蕴藏丰富的伴生金属资源,随着这类矿产资源价格上涨,尾砂伴生资源越来越受到人们的关注。本文对大厂矿集区茶山、车河、长坡和绿荫塘四个尾矿库中铟、镉、镓、锗等稀散元素分布特征与变化规律进行了调查,以期评价其潜在经济价值。调查结果表明,解放前修建的绿荫塘老尾矿库尾砂稀散元素铟、镉、锗均远超过工业品位,具有一定开采价值。70年代修建的长坡尾矿库铟、镉达到工业品位;90年代修建的车河、茶山尾砂库只有铟达到工业品位。四个尾矿库中稀散元素含量与尾砂来源和选矿水平密切相关,并发生次生淋滤富集作用。对环境有毒害的稀散元素镉尽管含量较高,但其主要赋存在闪锌矿中并没有释放到土壤环境中产生污染。这些调查研究结果将为政府部门和矿山企业决策提供依据。  相似文献   

Observational Investigation of the Statistical Properties of Surface-Layer Turbulence in a Suburban Area of São Paulo,Brazil: Objective Analysis of Scaling-Parameter Accuracy and Uncertainties     

da Silveira  Lucas Cardoso  de Oliveira  Amauri Pereira  Sánchez  Maciel Piñero  Codato  Georgia  Ferreira  Maurício Jonas  Marques Filho  Edson Pereira  Božnar  Marija Zlata  Mlakar  Primož 《Boundary-Layer Meteorology》2022,185(2):161-195

Boundary-Layer Meteorology - Statistical properties of turbulence, specifically variances of velocity components, temperature, water vapor, and carbon dioxide densities, are observationally...  相似文献   

Correlation between the Flux Density and Polarization for Flat Spectrum Radio Quasars     

Fei-Peng Pi  Yong-Xiang Wang  Jing Pan 《Journal of Astrophysics and Astronomy》2011,32(1-2):313-314

In this paper, using the preliminary database of the University of Michigan Radio Astronomy Observatory (UMRAO) at the radio frequencies, we calculated the weighted polarization at 8 GHz and investigated the correlation between the polarization and the flux density for 92 flat spectrum radio quasars (FSRQs). We found that the two observations are closely and positively correlated for FSRQs. This is perhaps from a relativistic beaming effect.  相似文献   

A methodological approach of fluvial dynamics oriented towards hydrosystem management: case study of the Loire and Allier rivers     

Emmanuèle Gautier  Hervé Piégay  Patrick Bertaina 《Geodinamica Acta》2013,26(1):29-43

Abstract

This study was conducted as part of the European LIFE Loire Nature program for the conservation and management of a 110-km-long section of the Loire and Allier rivers, an area renowned for its ecological richness. The methodological approach is based on statistical analysis (bivariate and multivariate analyses) of hydro-geomorphologic and biogeographical variables, complemented by reach typology and mapping. The main results show, on the one hand, the great spatial variability of fluvial mosaic complexity along the river continuum and on the other hand, some independence between the riparian forest characteristics and the channel forms. The fluvial pattern (e.g. anabranching) and the forest establishment along the Loire river register specific features. © 2000 Éditions scientifiques et médicales Elsevier SAS  相似文献   

Longitudinal and temporal thermal patterns of the French Rh?ne River using Landsat ETM+ thermal infrared images     

Vincent Wawrzyniak  Hervé Piégay  Alain Poirel 《Aquatic Sciences - Research Across Boundaries》2012,74(3):405-414

Understanding the thermal regime of rivers is a key issue for predicting ecosystem change in the context of global warming. However, water temperature is not only influenced by air temperature. To better highlight relative contribution of factors controlling water temperature, we used satellite thermal infrared (TIR) images from Landsat ETM+ to investigate longitudinal and temporal variations in thermal patterns of the French Rh?ne River. Because satellite TIR remote sensing is limited to large rivers, we used an automated water extraction technique to remove pixels contaminated by terrestrial surfaces. We calculated water surface temperatures of the 500?km long reach for 83 dates between 1999 and 2009. The average accuracy and uncertainty of our data, ±1.1 and ±0.4°C for reaches with more than 3?pixels across and ±1.4 and ±0.5°C for reaches with one to 3?pixels across, are comparable to other satellite TIR studies of rivers. Our results confirmed previous studies on the thermal impacts of tributaries and nuclear power plants on the Rh?ne, providing an understanding of their seasonal pattern and their longitudinal impact. We showed temperature differences of 0?C2°C within the largest hydroelectric bypass facilities between the bypass section and the canal, with Montélimar and Caderousse showing the most pronounced differences. Discussion points concern the potential impacts of tributaries and nuclear power plants on the spatio-temporal thermal patterns, as well as the factors responsible for thermal differences in the bypass facilities: length and minimum flow of the bypass section, and tributaries coming into this reach.  相似文献   

Adsorption of Phosphate by Biomass Char Deriving from Fast Pyrolysis of Biomass Waste     

Feng Peng  Pi‐Wen He  Yin Luo  Xiang Lu  Ying Liang  Jie Fu 《洁净——土壤、空气、水》2012,40(5):493-498

Biomass char (BC) deriving from fast pyrolysis of biomass was a potential adsorption material due to its relative high fixed‐carbon content and the inherent porous structures. Adsorption of phosphate from aqueous solution by BC was investigated in this paper. The results showed that the adsorption capacity of BC was dependent on pyrolysis conditions, such as temperature and holding time. The maximum adsorption capacity for phosphate was approximately 15.11 mg g^?1 at 298 K. The pseudo‐second order model of the adsorption kinetics indicated that the adsorption process was complex and several mechanisms were involved. Equilibrium isotherm was satisfactorily followed the Freundlich isotherm model. The K_F value in Freundlich equation gradually increased with elevating temperature. Moreover, the thermodynamic constants: ΔG⁰, ΔH⁰, and ΔS⁰ were evaluated as ?6.49 kJ mol^?1 (at 298 K), 13.41 kJ mol^?1, and 66.70 J mol^?1 K^?1, respectively. Phosphate adsorption onto BC was spontaneous and endothermic. As a waste, BC was a potentially attractive adsorbent for phosphate removal from aqueous solution with low cost and high capability.  相似文献   

Hydromorphological frameworks: emerging trajectories     

A. M. Gurnell  M. Rinaldi  A. D. Buijse  G. Brierley  H. Piégay 《Aquatic Sciences - Research Across Boundaries》2016,78(1):135-138

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广东始兴地区钨锡多金属矿找矿实践与探索     

肖惠良  陈乐柱  鲍晓明  范飞鹏  周延  姚正红  武玲  吴涵宇 《高校地质学报》2013,19(2):213

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Implementation and validation of video monitoring for wood budgeting in a wandering piedmont river,the Ain River (France)     

Bruce MacVicar  Hervé Piégay 《地球表面变化过程与地形》2012,37(12):1272-1289

The transport of wood in rivers during floods is an important process that underlies differences in habitat and morphology between water courses and regions. Quantitative data are needed to properly address management objectives and balance wood budgets. In this study we use a streamside video camera to detect wood passage and measure quasi‐instantaneous rates of wood transport in the Ain River, France. The objectives are to verify the procedure, describe the relation between wood transport and discharge, and construct and validate a wood budget for the reach upstream of the camera. Verification of the procedure includes tests of detection frequency, wood velocity, and piece size. A log base two transformation is proposed to classify wood by piece length. It was found that a wood transport threshold occurs at approximately two thirds of the bankfull discharge. Wood transport follows a positive linear relation with discharge up to the bankfull discharge but is both more variable and less sensitive to discharge when the floodplain is inundated. Transport rates are approximately four times higher on the rising limb of the hydrograph than on the falling limb. Wood transport estimates from a three‐stage rating curve are two to 10 times higher than those from a wood budget using local and aerial surveys of upstream dynamics. Future work should address uncertainties related to wood diameter measurements, sampling length and frequency, and antecedent floods. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

Mixed heavy metals tolerance and radial oxygen loss in mangrove seedlings   总被引：2，自引：0，他引：2  

Y. Liu  N.F.Y. Tam  J.X. Yang  N. Pi  M.H. Wong  Z.H. Ye 《Marine pollution bulletin》2009,(12):1843-1849

The effects of a mixture of heavy metals (Pb, Zn and Cu) on growth, radial oxygen loss (ROL) and the spatial pattern of ROL were investigated in mangrove seedlings of three species: Aegiceras corniculatum, Avicennia marina and Bruguiera gymnorrhiza. Heavy metals inhibited the growth of seedlings and led to decreased ROL and changes in the “tight” barrier spatial pattern of ROL. There was a significant positive correlation between the amount of ROL from the roots of seedlings and metal tolerance. The species with the highest ROL amount, B. gymnorrhiza, were also the most tolerant to heavy metals. The “tight” barrier spatial ROL pattern was also related to metal tolerance in the seedlings. Therefore, we conclude that both ROL amount and “tight” barrier spatial ROL pattern in the roots of the mangrove seedlings play an important role in resistance to heavy metal toxicity.  相似文献