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71.
Determination of cadmium(II), copper(II), manganese(II) and nickel(II) species in Antarctic seawater with complexing resins 总被引:1,自引:0,他引:1
Raffaela Biesuz Giancarla Alberti Girolamo D'Agostino Emanuele Magi Maria Pesavento 《Marine Chemistry》2006,101(3-4):180-189
The strong species of cadmium(II), copper(II), manganese(II) and nickel(II) in an Antarctic seawater sample are investigated by a method based on the sorption of metal ions on complexing resins. The resins compete with the ligands present in the sample to combine with the metal ions. Two resins with different adsorbing strengths were used. Very stable metal complexes were investigated with the strong sorbent Chelex 100 and weaker species with the less strong resin, Amberlite CG-50. Strong species were detected for three of the considered metal ions, but not for Mn(II). Cu(II) is completely linked to species with a side reaction coefficient as high as log αM(I) = 11.6 at pH = 7.3. The ligand concentration was found to be similar to that of the metal ion, and the conditional stability constant was around 1020 M− 1. In the considered sample, only a fraction of the metal ions Cd(II) and Ni(II) is bound to the strong ligands, with side reaction coefficients equal to log αM(I) = 5.5 and 6.5 at pH = 7.3 for Cd(II) and Ni(II), respectively. These findings were confirmed by the test with the weaker sorbent Amberlite CG-50. It can be calculated from the sorption equilibria that neither Mn(II) nor Ni(II) is adsorbed on Amberlite CG-50 under the considered conditions and, in fact, only a negligible fraction of Mn(II) and Ni(II) was adsorbed. A noticeable fraction of Cd(II) was adsorbed on Amberlite CG-50, meaning that cadmium(II) is partially linked to weak ligands, possibly chloride, while no copper(II) was adsorbed on this resin, confirming that copper(II) is only combined in strong species. These results are similar, but not identical, to those obtained for other seawater samples examined in previous investigations. 相似文献
72.
The relevant theory is presented and numerical results are compared with the analytical solution for the interaction of non-breaking waves with an array of vertical porous circular cylinders on a horizontal bed. The extension to the cases of unidirectional and multidirectional waves is obtained by means of a transfer function. The influence of the mechanical properties of porous structures and wave irregularity on wave transformation is analysed. Results for unidirectional and multidirectional wave spectra are compared to those obtained for regular waves. The model presented reproduces well the analytical results and provides a tool for analysing several engineering problems. 相似文献
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Most of the existing relevant materials have been obtained from experiments, in which evaluating the added mass at the resonant frequency corresponding to the peak of a frequency-response curve obtained from the “forced” vibration analysis is the most popular technique. In this paper, a simple experimental method was presented where the “free” vibration responses instead of the “forced” ones were used to determine the values of mah and Iap. The main part of the experimental system is composed of a floating body (model) and a spring–shaft shaker. The “free” vibration of this main part was induced by imposing on it an initial displacement (and/or an initial velocity), and from the time histories of displacements information such as the “damped” natural frequencies, damping ratios, sectional added mass coefficients (CV and CP) were obtained. Since the displacements of the spring–shaft shaker are “translational” and those of the floating body due to pitch motions are “angular”, a technique for the transformation between the associated parameters of the two components of the main part was presented. 相似文献
75.
柴达木盆地新构造运动主要特征与成因机制 总被引:10,自引:0,他引:10
杨明慧 《海洋地质与第四纪地质》1997,17(3):71-78
研究表明,在壳幔结构、地球物理背景、沉积物结构、多层关地幔和构造样式等方面,达木盆地与中国东部新生代裂谷类伸展盆地具有可比性,应该归属 展性盆 。盆地伸展和收缩作用相间进行,伸展起因于地幔底辟;而收缩受两人因素影响;(1)盆地伸展作用受相邻造山带反作用诱导的挤压应力;(2)板块碰撞传递的远程板内应力。在此基础邮新的构造期达木盆地演化的“双层模式”,即地幔上隆-地壳伸展;被动挤压+板内应力-地壳收缩 相似文献
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78.
对虾体内氯霉素含量测定方法的研究 总被引:1,自引:0,他引:1
应用HPLC技术建立常用药物氯霉素的虾体动力学研究方法。该方法的特点是:与微生物法、比色法、气相色谱法、荧光法及免疫法比较.测试准确、快速且灵敏度高。应用该方法可以从虾体内的血液、肌肉、肝胰脏、肠胃中分离出被虾吸收的氯霉素,并定量测定。在1—50μg/ml范围内线性关系相关系数为0.9995。 相似文献
79.
80.
为了实现现场测量地表水中矿物油含量的全光纤荧光计的研制。采用荧光光谱测量分析方法 ,于 1 999年 1 0月— 2 0 0 0年 5月 ,采集了国内外不同的地区原油和成品油共 2 3种 ,用1 4种不同波长的激发光激励 ,进行荧光光谱特性测量实验研究。同时 ,对不同浓度的矿物油、水混合液也进行了测量实验 ,得出其最低检测浓度为 0 .0 0 5mg/L ;测量了青岛近岸海域表层受油污染海水的含油量为 0 .0 1~ 0 .2 2mg/L ;此外对水中矿物油受激荧光发射原理也作了简述。并对水中矿物油荧光光谱特性、浓度与荧光强度的关系 ,以及为研制现场测量水中矿物油浓度的全光纤荧光计的可能性作出了结论性的意见 相似文献