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991.
992.
溪谷输变电站工程场地具有较复杂的双层地质结构.岩土体拉分变形明显.场地后缘及底部岩土体的主应力和剪应力集中明显,堆积体内部岩体处于拉分松弛状态.岩土体的潜在变形模式以蠕滑-拉裂为主.在水库蓄水与地震共同作用的极限工况下.场地处于潜在不稳定状态. 相似文献
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The Yitong(伊通) basin is a Late Mesozoic and Cenozoic continental sedimentary basin in Northeast China.On the basis of well tests and seismic data,we use the 2D modeling technique to rebuild the pressure evolution and hydrocarbon migration in the Moliqing(莫里青) fault depression of the Yitong basin.Based on the modeling results,four conclusions are drawn as follows.(1) The Eocene Shuangyang(双阳) Formation within the Moliqing fault depression had entirely undergone three epi-sodic cycles of pressure accumulation... 相似文献
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Source Apportionment of PAHs Using Two Mathematical Models for Mangrove Sediments in Shantou Coastal Zone,China 总被引:2,自引:0,他引:2
Thirty-five surface sediment samples collected from three mangroves in Shantou coastal zone, China in 2007 were analyzed for
a suite of polycyclic aromatic hydrocarbons (PAHs). Two mathematical models were used to determine the profiles and relative
contributions of PAH sources to the mangroves. The two models are principal component analyses (PCA) with multiple linear
regression analysis (MLR) and positive matrix factorization (PMF). Both models identified five factors and gave excellent
correlation coefficients between predicted and measured levels of 16 PAH compounds, but the results had some differences.
The PAH contribution rate attributed to vehicular emission sources identified by PCA-MLR was 37.20%, but the rate identified
by PMF was only 12.37%. The main sources identified by PCA-MLR were combination of biomass/coal combustion and vehicular emissions,
whereas the main source identified by PMF was only biomass/coal combustion. The PMF analysis was the preferred model for the
paper data set. 相似文献
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999.
Sorption and desorption behavior of lead on a Chinese kaolin 总被引:1,自引:0,他引:1
Shengli Wang Zhongren Nan Xinde Cao Qin Liao Jiao Liu Wenfei Wu Ting Zhou Cuicui Zhao Wangqiang Jin 《Environmental Earth Sciences》2011,63(1):145-149
The sorption and desorption of Pb on kaolin from Suzhou, China were investigated. The sorption experiment was conducted in
a 0.01 M NaNO3 aqueous solution with respect to the effects of initial Pb concentration, pH, solid/solution ratio, and temperature. Langmuir
and Freundlich models well described equilibrium isotherms of Pb sorption. Less than 5% of Pb sorbed was desorbed with 0.01 M
NaNO3 extraction, suggesting a dominant specific sorption of Pb. As the initial pH increased, the sorption of Pb on the kaolin
increased. More than 60% of Pb was sorbed at pH 2.69 far below the point of zero net charge of the kaolin at 4.2, indicating
a mechanism of Pb inner-sphere complex or by chemisorption. Lead sorption decreased with increasing temperature, indicating
a process of exothermic sorption. 相似文献
1000.
Sheng Kui Cao Qi Feng Yong Hong Su Zong Qiang Chang Hai Yang Xi 《Environmental Earth Sciences》2011,62(8):1597-1607
Seasonal variations in foliar stable carbon composition (δ13C) and nitrogen (N), phosphorus (P) and potassium (K) concentrations of Populus euphratica Olivier and Tamarix ramosissima Ledeb, as well as correlations between foliar δ13C values and N, P and K concentrations were studied in the Ejina oasis in the lower reaches of the Heihe River, northwestern
China. Foliar δ13C values, and P and K concentrations significantly differed between species. Foliar δ13C signatures in T. ramosissima were significantly more enriched than those in P. euphratica, but P and K concentrations of P. euphratica were higher. The seasonal variations and patterns of these were similar. The total foliar δ13C values and N, P and K concentrations in both P. euphratica and T. ramosissima showed a descending trend. There were significantly positive correlations between foliar δ13C values and N and P concentration of both P. euphratica and T. ramosissima. For the relationship between foliar δ13C and K concentration, there appeared oppositely positive and negative correlations in P. euphratica and T. ramosissima, respectively, but they were not significant. The simple positive correlations of δ13C–P% and δ13C–N% suggested that N and P in P. euphratica and T. ramosissima behave in a similar manner. This study also showed that there were nutrient deficiencies; N and P nutriments were the co-limiting
factors in P. euphratica, while it was P nutriment in T. ramosissima. 相似文献