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Dong‐Chan Koh Ho‐Wan Chang Kwang‐Sik Lee Kyung‐Seok Ko Yongje Kim Won‐Bae Park 《水文研究》2005,19(11):2225-2245
Ground water from springs and public supply wells was investigated for hydrochemistry and environmental isotopes of 3H, 18O and D in Jeju volcanic island, Korea. The wells are completed in a basaltic aquifer and the upper part of hydrovolcanic sedimentary formation. Nitrate contamination is conspicuous in the coastal area where most of the samples have nitrate concentrations well above 1 mg NO3 N/l. Agricultural land use seems to have a strong influence on the distribution of nitrate in ground water. Comparison of stable isotopic compositions of precipitation and ground water show that ground water mostly originates from rainy season precipitation without significant secondary modification and that local recharge is dominant. 3H concentration of ground water ranged from nearly zero to 5 TU and is poorly correlated with vertical location of well screens. The occurrence of the 3H‐free, old ground water is due to the presence of low permeability layers near the boundary of the basaltic aquifer and the hydrovolcanic sedimentary formation, which significantly limits ground water flow from the upper basaltic aquifer. The old ground water exhibited background‐level nitrate concentrations despite high nitrate loadings, whereas young ground water had considerably higher nitrate concentrations. This correlation of 3H and nitrate concentration may be ascribed to the history of fertilizer use that has increased dramatically since the early 1960s in the island. This suggests that 3H can be used as a qualitative indicator for aquifer vulnerability to nitrate contamination. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
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An understanding of groundwater flow and chemistry is important to operate underground storage caverns. Groundwater flow is mainly affected by cavern operating conditions. Groundwater chemistry is modified by disinfection activities for removing possible biological clogging and by mixing with cement pore water. It is important to discern these two effects, because wells affected by the disinfection activities may have hydrological connections with water curtains used to inject the disinfectant. However, it is difficult to separate these two effects using graphical methods because of their similar chemical characteristics. Instead, multivariate statistical analysis, such as principal component analysis (PCA) and factor analysis (FA), can be used. Groundwater samples for chemical analysis were obtained from four surveys in 1999–2000. Based on the results from PCA and FA, it appears that there were temporal variations of seepage water into the propane area when the cavern operation fluctuated, but we could not observe such variation in the butane area. These changes may occur mainly at depth, where water flow is slow and water renewal in the cavern surrounding is limited. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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湖泊沉积物中蛋白质和氨基酸的动态变化 总被引:5,自引:0,他引:5
测定了阿哈湖和百花湖沉积物孔隙水中蛋白质和氨基酸的含量。蛋白质含量分别在0.32-1.71mg/ml和0.22-1.38mg/ml之间,氨基酸含量分别在1.15-5.01μg/ml(以含N量计)和1.41-4.16μg/ml之间。两湖沉积物氨基酸含量逐渐增高,表明扩散作用的存在。随着时间的推移,蛋白质在沉积物各层中得到了很好的保存,说明它的分解比较有限。沉积物孔隙水中氨基酸含量和微生物活动有关,氨基酸在27cm以后的阿哈湖沉积物中明显积累,可能指示微生物活动的减弱。 相似文献
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地震数据交换标准(SEED)是国际地震数据交换的一种标准格式。本文简要介绍了台站磁带的SEED格式,详细分析了带有可变头段节的数据记录的结构,并给出了从带有可变头段节的数据记录中提取地震数据的实例。 相似文献
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小麦作物光合生产模拟研究 总被引:14,自引:0,他引:14
以生物学原理为基础,建立了小麦干物质增长的动态模式。该模式考虑了小麦株型、群体光分布、群体光合作用、呼吸作用及同化物分配。输入简单易测的因子,可计算得到光合速率值、群体光分布特征值、群体光合量、呼吸作用速率以及分部位干物重量等,其计算值与这关测值较吻合。 相似文献
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本文通过对AutoCAD技术的二次开发,实现了市政工程系列图图形的直观显示、编码管理、快速成图等功能。 相似文献