Influence of Decarbonisation and Phosphate Dosage on Copper Corrosion in Drinking Water Systems     

Jürgen Dartmann  Thore Alex  Thorsten Dorsch  Esther Schevalje  Klaus Johannsen 《洁净——土壤、空气、水》2004,32(1):25-32

The effect of softening/decarbonisation and dosage of orthophosphate on copper corrosion was studied in pipe rigs according to the German standard DIN 50931, part 1. A literature study with regard to the effects of phosphate dosing on copper corrosion has shown that on the one hand and in most of the cases a dosage of phosphate led to lower copper concentrations. On the other hand phosphate aggravated the copper corrosion in some cases. The mechanisms are not yet clear and the influence of phosphate on the corrosion of copper remains a question to be answered. Using standardised on‐site corrosion tests (DIN 50931‐1) with virgin copper pipes softening/decarbonisation has decreased the copper concentration. Two effects of phosphate on copper corrosion were noticed: Phosphate dosing decreased the copper oxidation and resulted in lower copper concentration in water. Likewise phosphate hindered the precipitation of cupric ions, which prolonged the existence of copper in water and resulted in a higher copper concentration. As a consequence, dosing phosphate can decrease or increase the copper corrosion, this depends on which effect is dominating.  相似文献   

淮北夹沟—桃山集地区推覆构造研究   总被引：1，自引：0，他引：1  

陈云棠  舒良树 《大地构造与成矿学》2000,24(3):208-217

本区存在大型中生代推覆构造,所有震旦纪—古生代的沉积岩层都卷入了褶皱和断裂,构造推覆发生在较高构造部位,属脆性变形域,以台阶状逆断层和断层相关褶皱为特征。区内存在若干推覆构造,每个岩片均可分为上盘、下盘和滑动层系三部分,共查明8个滑动岩系。是一种发生在早中生代的盖层推覆,无根褶皱,也是徐宿地区最重要的控煤构造。最后对推覆构造的地球动力学机制进行了讨论。  相似文献   

时间域航空电磁系统瞬变全时响应正演模拟   总被引：16，自引：10，他引：6       下载免费PDF全文

殷长春  黄威  贲放 《地球物理学报》2013,56(9):3153-3162

近年来很多专家学者致力于时间域航空系统正反演的研究.本文针对一维均匀层状介质和三维模型进行正演.不仅计算垂直方向上的电磁响应,还计算了同线方向上的电磁响应,为航空电磁多分量观测提供理论依据.通过比较航空电磁系统的脉冲响应和阶跃响应特征,发现脉冲响应在早期时间存在奇异性,造成计算不稳定.然而,阶跃响应在早期时间没有奇异性,因而利用系统的阶跃响应可得到一种计算时间域航空电磁系统全时响应的稳定算法.该算法具有较高的精度,并很好地保持了磁场强度B和磁感应dB/dt关系的一致性.该算法推广到三维地质体的时间域正演模拟亦取得很好的效果.  相似文献   

变电站接地电阻实例计算及降阻分析   总被引：2，自引：2，他引：0  

赵伟明  林铂岷 《气象研究与应用》2008,29(4):53-55

根据实际接地网所处环境因素的分析,对变电站所需的雷电系统的防护,依据国家制定的标准的要求,提出了具体解决方案。  相似文献   

STEP-POOL MORPHOLOGY IN HIGH-GRADIENT STREAMS   总被引：3，自引：0，他引：3  

A.R. MAXWELL  A.N. PAPANICOLAOU Research Assistant  Dept. of Civil  Envir. Engrg.  Washington State University  Pullman  WA -  Professor  Dept. of Civil  Envir. Engrg.  Washington State University  Pullman  WA - 《国际泥沙研究》2001,16(3)

l 1NTRODUCTIONGravel bed rivers are found in man parts of the worid, mpically in moUntainous regions with highgradients and seasonally high flows. These rivers are imPotalt in contrlling flood waters from sPringrunoff in regions such as the Pacific Northwest, Where heaVy snowfall can be followed by equally heaVyranfall. The combination of high stream gradient and high discharge causes significant erosion of thebed and bank of the strCam, in some cases moving large boulders with ease.It…  相似文献   

万全井水位阶变序列异常与地震关系初探   总被引：4，自引：0，他引：4  

曹新来 《中国地震》1993,9(4):320-326

本文研究了水位阶变异常与区域地震活动的关系。其思路是先把一系列水位阶变异常视为阶变序列异常，按阶变密集程序把序列异常分为几个子序列异常。然后分析各子序列异常的产生及其发展、演变过程与区域中强地震活动的关系，综合各子序列异常为序列异常，分析其与地震活动趋势的关系。应用上述方法，文章分析了万全井１９８１年以来记录到的一系更水位阶变异常与几次区域中强地震活动的关系。根据序列异常的阶变频次、幅度、方向变化  相似文献   

测试水井导水性能的简便试验          下载免费PDF全文

张昭栋  冯在成 《地震地质》1993,15(3):207-212

这种测试水井含水层导水系数的新方法是利用井口水面空气压力阶变试验,计算出聊城井含水层的导水系数为14.4m2/d,而通过抽水试验得出的导水系数为43.6m2/d,二者有相同的数量级,但新方法比抽水试验简单易行和经济快速,用它来解释地下水微动态更合理,容易推广应用  相似文献   

Bedload entrainment,travel lengths,step lengths,rest periods—studied with passive (iron,magnetic) and active (radio) tracer techniques     

Karl-Heinz Schmidt  Peter Ergenzinger 《地球表面变化过程与地形》1992,17(2):147-165

This paper reports results from bedload transport investigations with active (radio) and passive (iron, magnetic) tracers in the Lainbach, a step-pool mountain river, in Bavaria, Southern Germany. The spatial distributions of the iron tracers after flood events can be best described by exponential or Gamma distributions. There is some indication of a tendency of size-selective transport of the iron tracers, but there is also a considerable amount of scatter in the correlations between weight (size) and travel length owing to the masking influence of other variables, such as the shape of the particles and different positions in the river bed. The experiments with artificial magnetic tracers showed that elongated pebbles (rods) had the longest mean transport distance, platy ones (discs) remained relatively close to the starting points. The particles from the pool showed the greatest transport lengths and a 100 per cent chance of being eroded. The Pebble Transmitter System (PETSY) consists of transmitters implanted into individual pebbles, a computerized receiver, a stationary antenna system with an antenna switchboard, and a data logging system. The particles do not move continuously but in a series of transport steps and non-movement intervals. A single value for a given size-class is not adequate to describe the critical conditions of entrainment under natural circumstances. A probability approach is much more suitable. The critical unit discharges (total discharge divided by active channel width) along the measuring reach are dependent on river bed morphology. In the steps bedload needs higher unit discharges to be entrained. Once entrained, the transport of bedload is stochastic in nature and the single particle transport is controlled by the step lengths and the duration of rest periods. The distributions of both parameters can be approximated by exponential functions. Applying the stochastic concept proposed by Einstein the mean values of the random variables [step length] and [duration of rest period] measured with the PETSY technique were used for the simulation of spatial distributions of bedload particles from point sources. More field and laboratory data are needed to include varying flow and roughness conditions with tracers representing different particle characteristics.  相似文献   

一维声波方程联合反演的分步正则化法     

张文飞  李晓江 《CT理论与应用研究》1996,5(4):16-20

本文用一个纵波信息，对一维声波方程的速度和源函数进行联合反演，并考虑到声波方程的反问题是一个不适应问题，对源函数和波速分别和正则化法分步迭代求解，减少反问题的计算工作量，改善该问题的计算稳定性，为计算实际工程和岩性学问题供了一种方法。文中给出只用一个反问题补充条件同时进行多参数反演的公式，并对相应的数值算例进行分析和比较。  相似文献   

特大远震引起的形变观测变化图像   总被引：3，自引：0，他引：3  

孙毅  程万正 《内陆地震》2005,19(3):264-270

利用定点长水管倾斜仪、石英伸缩仪、金属摆倾斜仪、石英摆倾斜仪连续观测资料对特大远震引起的震时和震后形变效应进行了分析.分析结果表明定点连续形变观测台网能记录到不同方位地震的震时脉冲信号,其持续时间半小时到4小时;同时还能记录到一些地震的阶跃信号.水平摆倾斜仪（金属摆、石英摆）观测值的震后效应表现为大幅漂移,持续时间几天到一个月.对由特大远震引起的形变观测变化图像出现差异的原因进行了讨论.另外对震时阶跃变化图像、定点形变观测仪器长趋势的漂移项、观测台站所处的地质构造三者之间的关系进行了讨论.  相似文献