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In order to characterize the trophic state of the southern coastal waters of the Caspian Sea, trophic index (TRIX) as well as numerical analysis using cluster and discriminant analysis were employed in this study. Chemical and biological parameters (NO3, NO2, NH4, PT, DO, and Chla) used in this study were collected seasonally from summer 1999 to spring 2000. A new trophic index developed by modification of TRIX indicated mesotrophic to eutrophic conditions for the Caspian Sea. Numerical analysis revealed three groups of the study area and it was found that the used methods are in good agreement. Both of them predicted poor to moderate conditions in the western part of the study area and the numerical classification predicted trophic conditions in the study area. However, TRIX was found to be a more accurate and suitable method. It performs more conservatively than the numerical classification and characterized lower classes of water quality for the stations in central and eastern parts of the study area. 相似文献
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Alireza Feizbakhsh Fatemeh Makavipour Elham Moniri Mahshid Nikpour Nezhati 《毒物与环境化学》2013,95(10):1650-1658
Utilization of Amberlite XAD-2 surface modified by covalent immobilization of brilliant green through an azo spacer for adsorptive enrichment of Sn(II) from environmental and biological samples was highlighted. The resulting resin was characterized by Fourier transform infrared spectroscopy, elemental analysis, thermogravimetric analysis, and scanning electron microscopy. The resin retained Sn(II) ions at an optimum pH of 9.5 with a sorption capacity of 40 mg g?1. The modified sorbent could be reused for 10 cycles without significant changes in sorption capacity. The recovery of Sn(II) was 98% when eluted with 0.1 mol L?1 ethylenediaminetetraacetic acid. Scatchard analysis revealed that binding sites in the modified resin were homogeneous. The equilibrium adsorption data were analyzed using the Langmuir, Freundlich, Temkin, and Redlich–Peterson isotherm models. The method was applied with satisfactory results for determination of Sn(II) ions in human plasma and sea water. 相似文献
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Hamid Reza Seifi Azad Mard Ali Estiri Parinaz Hadadi Mahshid Seifi Azad Mard 《International journal of occupational safety and ergonomics》2013,19(4):570-577
Occupational accidents in the construction industry are more common compared with other fields and these accidents are more severe compared with the global average in developing countries, especially in Iran. Studies which lead to the source of these accidents and suggest solutions for them are therefore valuable. In this study a combination of the failure mode and effects analysis method and fuzzy theory is used as a semi-qualitative–quantitative method for analyzing risks and failure modes. The main causes of occupational accidents in this field were identified and analyzed based on three factors; severity, detection and occurrence. Based on whether the risks are high or low priority, modifying actions were suggested to reduce the occupational risks. Finally, the results showed that high priority risks had a 40% decrease due to these actions. 相似文献
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Banavi Parvaneh Sadeghi Ehsan Garavand Farhad Heydari Mahshid Rouhi Milad 《Environmental science and pollution research international》2020,27(31):38591-38601
Environmental Science and Pollution Research - The copper pots with an inner coating layer of tin have been remarkably used in many countries for a long time. In this study, leaching of some metals... 相似文献
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