Diurnal Variations of Atmospheric Hydrogen Peroxide Concentrations in Saxony (Germany)     

THOMAS GNAUK  WOLFGANG ROLLE†  GERALD SPINDLER 《Journal of Atmospheric Chemistry》1997,27(1):79-103

During a 3-year study, gaseous hydrogenperoxide (H₂O₂) concentrations were measuredas part of the SANA project at the Melpitz FieldResearch Station and in the city of Leipzig. Typicaldaily mean H₂O₂ mixing ratios on sunny dayswere 0.15 to 0.25 ppbv with maximum values of 0.3 to0.5 ppbv at Melpitz, and 0.3 to 0.6 ppbv with maximumvalues of 0.4 to 1.0 ppbv in Leipzig. Over the entireperiod of the project the maximum hourly mean valueswere 2.1 ppbv and 5.3 ppbv in Melpitz and Leipzig,respectively. The data were not complete enough to show a trend.Linear regression analysis shows, that ozone(O₃), temperature and solar radiation arepositively correlated with H₂O₂, whereasnitrogen oxides (NO_x), carbon monoxide (CO) andrelative humidity are negatively correlated. Negativecorrelation between H₂O₂ and CO is caused byjoint occurrence of CO with NO_x in exhaust gases.Negative correlation between H₂O₂ andrelative humidity is not necessarily in contradictionto the accelerating effect of water vapour onH₂O₂ formation. The strong positivecorrelation of H₂O₂ with the dew pointdifference however seems to better reflect theinfluence of water vapour. Multiple linear regression analysis (MLRA) of thecomponents measured, indicates the great influence of CO on the formation of H₂O₂ in the gasphase.  相似文献   

影响上海市地价空间分布的区位因子分析   总被引：28，自引：5，他引：28  

杜德斌  徐建刚 《地理学报》1997,52(5):403-411

本文采用ＧＩＳ技术和多元线性回归分析方法，以土地批租地块为样本，分析上海市地价与城市区位因子的线性关系。回归分析结果表明；南京路，市中心和淮海路是影响上海市寺价空间差异的主要区位因子，外滩，次级商业中心和交通结节点对地价的影响很小，表明上海市地价的空间分布具有很高的向心性。  相似文献   

脉金矿床控矿条件及源区性质刍议   总被引：2，自引：0，他引：2  

孙景贵  李德季 《世界地质》1997,16(1):43-48

目前对脉金矿床，特别是大型金矿床的形成研究已取得重要进展，它在时间和空间上具有明显的一致性表明：大型脉金矿床的形成与特定的地质背景有密切关系，矿源具有深源性质，而与探矿岩系金的丰度值基本无关。  相似文献   

浅谈环境地质与环境保护     

丁冰 《陕西地质》1997,(2)

环境问题已成为全世界共同关心的问题。地质环境是影响人类生存的重要因素。本文述及了因自然地质因素引起的地震灾害、火山灾害、滑坡灾害等，以及因人为地质因素引发的水污染灾害、水库失事灾害、水土流失、沙漠扩大灾害等诸方面内容，指出在今后应重视对地质灾害的监测和预防。  相似文献   

硫酸盐渍土膨胀规律的综合影响因素的试验研究   总被引：9，自引：3，他引：9  

高江平  邓友生 《冰川冻土》1996,18(2):170-177

对含氯化钠硫酸盐渍土的膨胀规律作了综合影响因素的研究，首次提出了５因素盐胀率的计算公式，并得出了盐胀率的单因素和交互作用影响的规律；另外找出了某些因素的定量指标。  相似文献   

北京西山地面塌陷的形成因素浅析     

单青生 《城市地质》1996,8(2):1-10

地下采矿是地面塌陷失决条件，自然重力及其他外界触发因素是其发展动因，地面塌陷受覆岩时代及岩性，采空区尺寸大小，煤层倾角，煤层厚度及开采深度，重复采动，水文条件变化，地形地势和松散盖层的影响。  相似文献   

斜坡稳定性分析的模糊综合评判应用初探   总被引：1，自引：0，他引：1       下载免费PDF全文

冉恒谦 《探矿工程》1996,(6):19-22

采用两级模糊综合评判方法，在对评判实例的稳定性因素的定性分析基础上，选取主要因素四类１４项作为稳定性评价指标并将其定量化，按稳定，较稳定，较不稳定和不稳定四个级别进行综合评判，评判结果与斜坡的实际情况有较好的一致性。  相似文献   

Site effects at a vertical accelerometer array near Paducah, Kentucky     

R. Street  Z. Wang  E. Woolery  J. Hunt  J. Harris 《Engineering Geology》1997,46(3-4):349-367

The downhole vertical accelerometer array VSAP near Paducah, KY, consists of three-component accelerometers at the surface, the top of the McNairy Formation (−41 m), and the top of the Paleozoic bedrock (—99 m). The array is at the northern end of the Mississippi Embayment, and it was installed to verify the ground-motion modeling for the site, assuming a significant earthquake in the New Madrid Seismic Zone. Accelerograms from 4.2 and 2.0 m_b earthquakes were used to check aspects of the modeling pertaining to linear behavior of the soil column, and to review the soil column models derived by drilling and geotechnical methods and through the use of high-resolution P- and SH-wave seismic refraction in reflection techniques. Results of the study indicate that for the linear case the soil column models derived by the two techniques are equivalent, and that the most important boundary in the soil column, with respect to amplification of the ground motions, is the interface between the limestone bedrock and soil.  相似文献   

地下水中氟形成的控制因素及其分布规律   总被引：11，自引：0，他引：11  

曾昭华 《吉林地质》1997,16(4):26-31

本文研究了地下水中氟元素形成的主要控制因素及其分布规律。结果表明，地下水氟的形成与断裂构造，地下水温度、气候条件、含水介质及其上覆土层中的氟含量，地下水的酸碱度与径流条件有密切的关系。深成断裂脉状地下水和萤石矿区的地下水氟含量高，不有作为生活饮用水源； 而浅层的地下水氟含量较低，大多数仍作为生活饮用水源。  相似文献   

Effects of geology and human activity on the dynamics of salt-water intrusion in three coastal aquifers in southern Spain   总被引：4，自引：0，他引：4  

M. L. Calvache  A. Pulido-Bosch 《Environmental Geology》1997,30(3-4):215-223

 Mathematical modelling of salt-water intrusion processes in three aquifers on the southern coast of Spain (Río Verde, Río Vélez and Castell de Ferro) reveals that, although all three systems are subject to the same climate and seasonal over-exploitation, geological and human factors have very different effects on the dynamics of contamination. In the Río Verde aquifer, the most important influence is the high volume of extractions occurring during the dry season; in Río Vélez, the intrusion is strongly controlled by infiltration of water from the river to the aquifer, and, in the Castell de Ferro system, an intensely karstified carbonate massif lying in contact with both the sea water and the detrital aquifer represents the main entrance point for influx of sea water and subsequent washing of the aquifer. We have undertaken a mathematical simulation of various possible measures to counteract intrusion, according to the specific characteristics of the process in each aquifer. These measures include artificial recharge, use of natural recharge from the river as a hydraulic barrier, and the construction of a low-permeability barrier. Received: 5 December 1995 · Accepted: 12 April 1996  相似文献