A laboratory study was conducted in order to explain successive extractions of reserved potassium by using concentrated HCI under reflux for 13 surface and sub-surface soil samples representing three chosen pedons of ...A laboratory study was conducted in order to explain successive extractions of reserved potassium by using concentrated HCI under reflux for 13 surface and sub-surface soil samples representing three chosen pedons of soil series （472 ECC Bashika, 463 EKC Rabeaa and 461 ECC Talafar） locations of Nineveh Province in Northern of Iraq. The aim is to investigate role of clay minerals on release of reserved potassium from soils. Results showed that dominated clay minerals were （smectite 〉 illite 〉 kaolinite 〉 chlorite） for both 472 ECC and 461 ECC soil series and were （illite 〉 smectite 〉 kaolinite 〉 chlorite） for 463 EKC soil series. Also results appeared that exchangeable K＋ released values were 2,483-4,575 mg/kg at 461 ECC and 463 EKC soil series, respectively; non-exchangeable phase ranged from 752-1,390 mg/kg at 461 ECC and 472 ECC soil series, respectively. Soil fertility was evaluated according to its K＋ mica release referring for high K＋ release content with range between 3,324-5,516 mg/kg at 461 ECC and 463 EKC soil series, but rate ofK~ released was very law according to parabolic diffusion me,del with range from 195-359 mg/kg at latter soil series respectively. Results reflect effect of clay minerals on potassium release as amount and rates in arid and semi-arid regions. It can be concluded the study soils have a high amount of potassium content with low rate release of it, in turn these soil need particular management.展开更多
In this paper, dynamic soil parameters derived from Dalian area seismic risk assessment reports are collected. In this study, the measurement data is divided into 7 types, i.e. silty clay, muddy silty clay, clay, medi...In this paper, dynamic soil parameters derived from Dalian area seismic risk assessment reports are collected. In this study, the measurement data is divided into 7 types, i.e. silty clay, muddy silty clay, clay, medium sand, rock fragments, backfill soil and fully-weathered slate. Statistics of the dynamic parameters of these soils are carried out to obtain the mean values of dynamic shear modulus ratio and damping ratio. Typical drill holes are selected to establish dynamic soil models to investigate the seismic response for various cases. The dynamic parameters of the models are taken from the statistical values of this study, the standard values of code 94 (i.e. the dynamic soil parameters for Dalian seismic microzonation), and the recommended values by Yuan Xiaoming et al. (2000) respectively. The calculated results of peak ground acceleration are compared with the response spectral characteristics. The results show that the statistical values are approximate to the values recommended by Yuan Xiaoming, et al. (2000), but different greatly with the standard values in code 94.展开更多
文摘A laboratory study was conducted in order to explain successive extractions of reserved potassium by using concentrated HCI under reflux for 13 surface and sub-surface soil samples representing three chosen pedons of soil series （472 ECC Bashika, 463 EKC Rabeaa and 461 ECC Talafar） locations of Nineveh Province in Northern of Iraq. The aim is to investigate role of clay minerals on release of reserved potassium from soils. Results showed that dominated clay minerals were （smectite 〉 illite 〉 kaolinite 〉 chlorite） for both 472 ECC and 461 ECC soil series and were （illite 〉 smectite 〉 kaolinite 〉 chlorite） for 463 EKC soil series. Also results appeared that exchangeable K＋ released values were 2,483-4,575 mg/kg at 461 ECC and 463 EKC soil series, respectively; non-exchangeable phase ranged from 752-1,390 mg/kg at 461 ECC and 472 ECC soil series, respectively. Soil fertility was evaluated according to its K＋ mica release referring for high K＋ release content with range between 3,324-5,516 mg/kg at 461 ECC and 463 EKC soil series, but rate ofK~ released was very law according to parabolic diffusion me,del with range from 195-359 mg/kg at latter soil series respectively. Results reflect effect of clay minerals on potassium release as amount and rates in arid and semi-arid regions. It can be concluded the study soils have a high amount of potassium content with low rate release of it, in turn these soil need particular management.
文摘In this paper, dynamic soil parameters derived from Dalian area seismic risk assessment reports are collected. In this study, the measurement data is divided into 7 types, i.e. silty clay, muddy silty clay, clay, medium sand, rock fragments, backfill soil and fully-weathered slate. Statistics of the dynamic parameters of these soils are carried out to obtain the mean values of dynamic shear modulus ratio and damping ratio. Typical drill holes are selected to establish dynamic soil models to investigate the seismic response for various cases. The dynamic parameters of the models are taken from the statistical values of this study, the standard values of code 94 (i.e. the dynamic soil parameters for Dalian seismic microzonation), and the recommended values by Yuan Xiaoming et al. (2000) respectively. The calculated results of peak ground acceleration are compared with the response spectral characteristics. The results show that the statistical values are approximate to the values recommended by Yuan Xiaoming, et al. (2000), but different greatly with the standard values in code 94.
