The environmental load chart is an important technical support required for the jack-up drilling platform to facilitate its adaptation to different operating waters and ensure the safety of operation.This chart is a c...The environmental load chart is an important technical support required for the jack-up drilling platform to facilitate its adaptation to different operating waters and ensure the safety of operation.This chart is a crucial part of the platform operation manual.The chart data are closely related to external factors such as water depth,wind,wave,and current conditions of the working water,as well as to the structural characteristics of the platform itself and the number of variable loads.This study examines the platform state under extreme wind,wave,and current conditions during preloading.In addition,this study focuses on the difference between the ultimate reaction force of the pile leg during preloading and the reaction force of the pile leg without considering any environmental load before preloading.Furthermore,the relationship between the difference and the new reaction force of the pile leg caused by the combination of different environmental conditions is established to facilitate the construction of a new form of environmental load chart.The newly formed chart is flexible and simple;thus,it can be used to evaluate the environmental adaptability of the platform in the target well location and provides the preloading target demand or variable load limit according to the given environmental constraints.Moreover,the platform can perform personalized preloading operations,thereby improving its capability to cope with complex geological conditions,such as reducing punch-through risks.This condition reduces the load on jacking system devices and increases its service life.展开更多
[Objectives] This study was conducted to optimize the extraction process of Sipunculus nudus polysaccharide. [Methods]S. nudus polysaccharide was extracted by ultrasonic water extraction,with the marine S. nudus as a ...[Objectives] This study was conducted to optimize the extraction process of Sipunculus nudus polysaccharide. [Methods]S. nudus polysaccharide was extracted by ultrasonic water extraction,with the marine S. nudus as a raw material from Sanya City,Hainan Province,by single factor variable method,to find the optimal extraction conditions including ultrasonic power,solid-liquid ratio,ultrasonic extraction temperature,ultrasonic extraction time,ultrasonic extraction times and lye concentration. The absorbance of the polysaccharide was determined by an ultraviolet spectrophotometer,and polysaccharide yield were calculated. The antioxidant activity of scavenging hydroxyl and DPPH radicals was measured at different concentrations. [Results]The optimal extraction conditions for S. nudus polysaccharide were as follows： solid-liquid ratio at 1∶11 mg/ml,extraction temperature at 60 ℃,three times of ultrasonic extraction,ultrasonic power of 960 W,extraction time of 1. 5 h,and lye concentration of 5%,under which the polysaccharide yield was 3. 21%. The scavenging rates of hydroxyl radical and DPPH radical were 12. 58% at the concentration of 0. 20 mg/ml. Moreover,the scavenging rates increased significantly with the increase of concentration. [Conclusions] This method is a new trial with satisfactory results.展开更多
The diffusion of potassium sorbate incorporated into gelatin based antimicrobial film was measured. Fick’s second law was applied to investigate the mechanism of potassium sorbate released from the films. The mathema...The diffusion of potassium sorbate incorporated into gelatin based antimicrobial film was measured. Fick’s second law was applied to investigate the mechanism of potassium sorbate released from the films. The mathematical model was established. The result showed that the diffusion coefficient D increased with the increase of potassium sorbate concentration. The effects of temperature 5?C, 25?C and 35?C on diffusion were investigated. The mechanisms of potassium sorbate diffusion through gelatin films were mainly Fickian and determined by the power law model M<sub>t</sub>/M<sub>∞</sub> = k × t<sup>n</sup>. A decrease in temperature from 35?C to 5?C resulted in a reduction of diffusion coefficients from 5.20 × 10<sup>?</sup><sup>12</sup> to 1.36 × 10<sup>?12 </sup>m<sup>2</sup>/s. The diffusion coefficient of potassium sorbate is influenced by receiving solution pH values.展开更多
基金Supported by the National Natural Science Foundation of China Youth Fund under Grant No.51909148the Doctoral Research Initiation Fund of Shandong Jiaotong University under Grant No.BS2018001。
文摘The environmental load chart is an important technical support required for the jack-up drilling platform to facilitate its adaptation to different operating waters and ensure the safety of operation.This chart is a crucial part of the platform operation manual.The chart data are closely related to external factors such as water depth,wind,wave,and current conditions of the working water,as well as to the structural characteristics of the platform itself and the number of variable loads.This study examines the platform state under extreme wind,wave,and current conditions during preloading.In addition,this study focuses on the difference between the ultimate reaction force of the pile leg during preloading and the reaction force of the pile leg without considering any environmental load before preloading.Furthermore,the relationship between the difference and the new reaction force of the pile leg caused by the combination of different environmental conditions is established to facilitate the construction of a new form of environmental load chart.The newly formed chart is flexible and simple;thus,it can be used to evaluate the environmental adaptability of the platform in the target well location and provides the preloading target demand or variable load limit according to the given environmental constraints.Moreover,the platform can perform personalized preloading operations,thereby improving its capability to cope with complex geological conditions,such as reducing punch-through risks.This condition reduces the load on jacking system devices and increases its service life.
基金Supported by National Natural Science Foundation of Hainan Province(217157)Fund for Construction of Provincial Key Discipline(thalassochemistry)in 2017
文摘[Objectives] This study was conducted to optimize the extraction process of Sipunculus nudus polysaccharide. [Methods]S. nudus polysaccharide was extracted by ultrasonic water extraction,with the marine S. nudus as a raw material from Sanya City,Hainan Province,by single factor variable method,to find the optimal extraction conditions including ultrasonic power,solid-liquid ratio,ultrasonic extraction temperature,ultrasonic extraction time,ultrasonic extraction times and lye concentration. The absorbance of the polysaccharide was determined by an ultraviolet spectrophotometer,and polysaccharide yield were calculated. The antioxidant activity of scavenging hydroxyl and DPPH radicals was measured at different concentrations. [Results]The optimal extraction conditions for S. nudus polysaccharide were as follows： solid-liquid ratio at 1∶11 mg/ml,extraction temperature at 60 ℃,three times of ultrasonic extraction,ultrasonic power of 960 W,extraction time of 1. 5 h,and lye concentration of 5%,under which the polysaccharide yield was 3. 21%. The scavenging rates of hydroxyl radical and DPPH radical were 12. 58% at the concentration of 0. 20 mg/ml. Moreover,the scavenging rates increased significantly with the increase of concentration. [Conclusions] This method is a new trial with satisfactory results.
文摘The diffusion of potassium sorbate incorporated into gelatin based antimicrobial film was measured. Fick’s second law was applied to investigate the mechanism of potassium sorbate released from the films. The mathematical model was established. The result showed that the diffusion coefficient D increased with the increase of potassium sorbate concentration. The effects of temperature 5?C, 25?C and 35?C on diffusion were investigated. The mechanisms of potassium sorbate diffusion through gelatin films were mainly Fickian and determined by the power law model M<sub>t</sub>/M<sub>∞</sub> = k × t<sup>n</sup>. A decrease in temperature from 35?C to 5?C resulted in a reduction of diffusion coefficients from 5.20 × 10<sup>?</sup><sup>12</sup> to 1.36 × 10<sup>?12 </sup>m<sup>2</sup>/s. The diffusion coefficient of potassium sorbate is influenced by receiving solution pH values.
