Heat source function method is adopted in the present paper to derive elementary solutions of coupled thermo-hydro-mechanical consolidation for saturated porous media under conjunct actions of instantaneous point heat...Heat source function method is adopted in the present paper to derive elementary solutions of coupled thermo-hydro-mechanical consolidation for saturated porous media under conjunct actions of instantaneous point heat source, instantaneous point fluid source and constant volume force. By using the so-called fictitious heat source method and images method, the solutions of a semi-infinite saturated porous medium subjected to a local heat source with time-varied intensity on its free surface are developed from elementary solutions. The numerical integral methods for calculating the unsteady temperature, pore pressure and displacement fields are given. The thermomechanical response are analyzed for the case of a circular planar heat source. Besides, the thermal consolidation characteristics of a saturated porous medium subjected to a harmonic thermal loading are also given, and the fluctuation processes of the field variables located below the center of heat source are analyzed.展开更多
In this paper, the saturated solution crystallization method is proposed to promote the formation of hydrate by means of the known similarities between the hydrate formation process and the crystallization process. In...In this paper, the saturated solution crystallization method is proposed to promote the formation of hydrate by means of the known similarities between the hydrate formation process and the crystallization process. In this method,adding the second phase crystals was used to replace the spontaneous formation of hydrate crystal nuclei to form hydrate.The effects of saturated Na_2SO_4, MgSO_4, NH_4HCO_3 and CuSO_4 solutions on the formation rates of natural gas hydrate and gas storage capacity were investigated. The results showed that the saturated solution had an influence on the hydrate formation process. Under the given experimental conditions, the saturated Na_2SO_4 solution showed a highest increase in the hydrate formation rate, and the average hydrate formation rate in its presence was 11.8 times higher than that obtained in the deionized water. Moreover, the largest formation rate of gas hydrates observed in the saturated Na_2SO_4 solution was 386 times bigger than that in the deionized water, and the gas storage capacity increased by 10 times. In addition, the average hydrate formation rate in the saturated Mg SO_4 solution was faster than that in water by 20 times. The largest formation rate of gas hydrates in the saturated MgSO_4 solution was 165 times faster than that obtained in the deionized water, and the gas storage capacity increased by 6.2 times. The saturated NH_4HCO_3 and saturated CuSO_4 solutions also influenced the formation process of hydrate. Therefore, the crystallization method of saturated solution can be used to achieve a highefficiency preparation of natural gas hydrates, which provides theoretical guidance for the storage of natural gas in the form of hydrate.展开更多
Since the separation of crystal of KCl saturated aqueous is similar to the crystallization of liquid metals, the melts nucleation can be simulated by the experiment of the crystal of salt aqueous solution. In this exp...Since the separation of crystal of KCl saturated aqueous is similar to the crystallization of liquid metals, the melts nucleation can be simulated by the experiment of the crystal of salt aqueous solution. In this experiment pulsation treatment was imposed on KCl saturated aqueous in order to study the effect of pulsation treatment on crystallization in the salt solution, and the influence of different pulsation treating time, super-heating and bine of prescription were investigated. The results show that it is possible to modify the crystallization over satured solution temperature and the degree of under-cooling for salt crystal separation was reduced by applying pulse treating on KCl saturated aqueous solution. In addition, this technology may generate embryos for nucleation even at the temperature over melting point or satured solubility.展开更多
In this work, the optimal clathration condition was investigated for the preparation of aspirin-β-cyclodextrin (Asp-β-CD) inclusion complex using design of experiment (DOE) methodology. A 3-level, 3-factor Box-B...In this work, the optimal clathration condition was investigated for the preparation of aspirin-β-cyclodextrin (Asp-β-CD) inclusion complex using design of experiment (DOE) methodology. A 3-level, 3-factor Box-Behnken design with a total of 17 experimental runs was used. The Asp-β-CD inclusion complex was prepared by saturated solution method. The influence on the embedding rate was investigated, including molar ratio of β-CD to Asp, clathration temperature and clathration time, and the optimum values of such three test variables were found to be 0.82, 49C and 2.0 h, respectively. The embedding rate could be up to 61.19%. The formation of the bonding between -COOH group of Asp and O-H group of β-CD might play an important role in the process of clathration according to FT-IR spectra. Release kinetics of Asp from inclusion complex was studied for the evaluation of drug release mechanism and diffusion coefficients. The results showed that the drug release from matrix occurred through Fickian diffusion mechanism. The cumulative release of Asp reached only 40% over 24 h, so the inclusion complex could potentially be applied as a long-acting delivery system.展开更多
基金The project supported by the National Natural Science Foundation of China (50578008) The English text was polished by Yunming Chen
文摘Heat source function method is adopted in the present paper to derive elementary solutions of coupled thermo-hydro-mechanical consolidation for saturated porous media under conjunct actions of instantaneous point heat source, instantaneous point fluid source and constant volume force. By using the so-called fictitious heat source method and images method, the solutions of a semi-infinite saturated porous medium subjected to a local heat source with time-varied intensity on its free surface are developed from elementary solutions. The numerical integral methods for calculating the unsteady temperature, pore pressure and displacement fields are given. The thermomechanical response are analyzed for the case of a circular planar heat source. Besides, the thermal consolidation characteristics of a saturated porous medium subjected to a harmonic thermal loading are also given, and the fluctuation processes of the field variables located below the center of heat source are analyzed.
基金the Program for Liaoning Excellent Talents in University (LJQ2014038)the Natural Science Foundation of Liaoning Province (201602470)
文摘In this paper, the saturated solution crystallization method is proposed to promote the formation of hydrate by means of the known similarities between the hydrate formation process and the crystallization process. In this method,adding the second phase crystals was used to replace the spontaneous formation of hydrate crystal nuclei to form hydrate.The effects of saturated Na_2SO_4, MgSO_4, NH_4HCO_3 and CuSO_4 solutions on the formation rates of natural gas hydrate and gas storage capacity were investigated. The results showed that the saturated solution had an influence on the hydrate formation process. Under the given experimental conditions, the saturated Na_2SO_4 solution showed a highest increase in the hydrate formation rate, and the average hydrate formation rate in its presence was 11.8 times higher than that obtained in the deionized water. Moreover, the largest formation rate of gas hydrates observed in the saturated Na_2SO_4 solution was 386 times bigger than that in the deionized water, and the gas storage capacity increased by 10 times. In addition, the average hydrate formation rate in the saturated Mg SO_4 solution was faster than that in water by 20 times. The largest formation rate of gas hydrates in the saturated MgSO_4 solution was 165 times faster than that obtained in the deionized water, and the gas storage capacity increased by 6.2 times. The saturated NH_4HCO_3 and saturated CuSO_4 solutions also influenced the formation process of hydrate. Therefore, the crystallization method of saturated solution can be used to achieve a highefficiency preparation of natural gas hydrates, which provides theoretical guidance for the storage of natural gas in the form of hydrate.
文摘Since the separation of crystal of KCl saturated aqueous is similar to the crystallization of liquid metals, the melts nucleation can be simulated by the experiment of the crystal of salt aqueous solution. In this experiment pulsation treatment was imposed on KCl saturated aqueous in order to study the effect of pulsation treatment on crystallization in the salt solution, and the influence of different pulsation treating time, super-heating and bine of prescription were investigated. The results show that it is possible to modify the crystallization over satured solution temperature and the degree of under-cooling for salt crystal separation was reduced by applying pulse treating on KCl saturated aqueous solution. In addition, this technology may generate embryos for nucleation even at the temperature over melting point or satured solubility.
文摘In this work, the optimal clathration condition was investigated for the preparation of aspirin-β-cyclodextrin (Asp-β-CD) inclusion complex using design of experiment (DOE) methodology. A 3-level, 3-factor Box-Behnken design with a total of 17 experimental runs was used. The Asp-β-CD inclusion complex was prepared by saturated solution method. The influence on the embedding rate was investigated, including molar ratio of β-CD to Asp, clathration temperature and clathration time, and the optimum values of such three test variables were found to be 0.82, 49C and 2.0 h, respectively. The embedding rate could be up to 61.19%. The formation of the bonding between -COOH group of Asp and O-H group of β-CD might play an important role in the process of clathration according to FT-IR spectra. Release kinetics of Asp from inclusion complex was studied for the evaluation of drug release mechanism and diffusion coefficients. The results showed that the drug release from matrix occurred through Fickian diffusion mechanism. The cumulative release of Asp reached only 40% over 24 h, so the inclusion complex could potentially be applied as a long-acting delivery system.