Matrix porosity calculations of fractured and vuggy reservoirs, such as volcanics and weathered dolomite, are one of the problems urgently needed to solve in well-log evaluation. In this paper, we first compare the an...Matrix porosity calculations of fractured and vuggy reservoirs, such as volcanics and weathered dolomite, are one of the problems urgently needed to solve in well-log evaluation. In this paper, we first compare the an empirical formula for porosity calculation from full diameter rhyolite core experiments with the matrix porosity formulas commonly used. We discuss the applicability of the empirical formula in fractured and vuggy reservoirs, such as intermediate-basic volcanics and weathered dolomite. Based on core analysis data, the error distribution of the calculated porosity of our empirical formula and the other porosity formulas in these reservoirs are given. The statistical error analysis indicates that the our empirical formula provides a higher precision than the other porosity formulas. When the porosity is between 1.5% and 15%, the acoustic experiment formula can be used not only for acidic volcanics but also in other fractured and vuggy reservoirs, such as intermediate-basic volcanics and weathered dolomite. Moreover, the formula can reduce the effects of borehole enlargement and rock alteration on porosity computation.展开更多
To master theoretical calculation for dust removal efficiency of high pressure atomization in an underground coal mine, the corresponding atomization characteristics and dust removal efficiency were both comprehensive...To master theoretical calculation for dust removal efficiency of high pressure atomization in an underground coal mine, the corresponding atomization characteristics and dust removal efficiency were both comprehensively studied in theory by virtue of related theories of hydromechanics and aerosol.According to actual measurements of flow coefficients and atomization angles of X-type swirl nozzle,computational formula was derived for atomized particle sizes of such a nozzle in conjunction with relevant empirical equation. Moreover, a mathematical model for applying high pressure atomization to dust removal in underground coal mine was also established to deduce theoretical computation formula of fractional efficiency. Then, Matlab was adopted to portray the relation curve between fractional efficiency and influence factors. In addition, a theoretical formula was also set up for removal efficiency of respirable dust and total coal dust based on dust size and frequency distribution equations. In the end,impacts of dust characteristic parameters on various dust removal efficiencies were analyzed.展开更多
When hitting underground structures directly or exploding in rock-soil media near underground structures, the conventional weapons with large charge weight will make underground structures be subjected to strong shock...When hitting underground structures directly or exploding in rock-soil media near underground structures, the conventional weapons with large charge weight will make underground structures be subjected to strong shock vibration and cause personal casualty and damage of precision electronic equipments. The shock vibration has become one of the cardinal killing means of weapons. However, the existing methods of predicting structure shock vibration are limited evidently. In this paper the coupling coefficient of acceleration in clayey soil is obtained firstly. Subsequently based on repeated experiments of chemical explosion, after dimension analysis and by using method of multivariate stepwise regression, the calculation formulae of shock vibration acceleration for the underground structure are obtained finally. The formulae consider top and side explosion respectively, taking into account the effects of penetration depth, charge weight, distance to explosion center, rock-soil media, size of structure and buried depth. They are easy to use with high practicability and degree of confidence, and can provide credible evidence for prediction of shock vibration and vibration isolating design of underground structure.展开更多
Emodin is a kind of anthraquiones with pharmaceutical activities.The solubilities of emodin in ethanol,1-octanol,and ethanol+1-octanol at different temperatures were measured using an analytical method.The solubility ...Emodin is a kind of anthraquiones with pharmaceutical activities.The solubilities of emodin in ethanol,1-octanol,and ethanol+1-octanol at different temperatures were measured using an analytical method.The solubility of emodin in these solvents increased with an increase in temperature.With the temperature deviating from room temperature,the dependence of the solubility of emodin on temperature became a lot more remarkable.The solubility of emodin in ethanol was more sensitive to temperature than that in 1-octanol.The solubility data of emodin in the same species of solvent at different temperatures was correlated with an empirical equation.The calculated results agreed with the experimental data well.展开更多
In order to minimize the harm caused by the instability of a planing craft, a motion prediction model is essential. This paper analyzed the feasibility of using an MGM（1,N） model in grey system theory to predict pla...In order to minimize the harm caused by the instability of a planing craft, a motion prediction model is essential. This paper analyzed the feasibility of using an MGM（1,N） model in grey system theory to predict planing craft motion and carried out the numerical simulation experiment. According to the characteristics of planing craft motion, a recurrence formula was proposed of the parameter matrix of an MGMfl,N） model. Using this formula, data can be updated in real-time without increasing computational complexity significantly. The results of numerical simulation show that using an MGM（1,N） model to predict planing motion is feasible and useful for prediction. So the method proposed in this study can reflect the planing craft motion mechanism successfully, and has rational and effective functions of forecasting and analyzing trends.展开更多
基金sponsored by the Science Research and Technology Development Project of Petrochina Company Limited "Well Logging Interpretation and Integrative Evaluation of the Complex Lithology"(Grant No.2008A-2705)
文摘Matrix porosity calculations of fractured and vuggy reservoirs, such as volcanics and weathered dolomite, are one of the problems urgently needed to solve in well-log evaluation. In this paper, we first compare the an empirical formula for porosity calculation from full diameter rhyolite core experiments with the matrix porosity formulas commonly used. We discuss the applicability of the empirical formula in fractured and vuggy reservoirs, such as intermediate-basic volcanics and weathered dolomite. Based on core analysis data, the error distribution of the calculated porosity of our empirical formula and the other porosity formulas in these reservoirs are given. The statistical error analysis indicates that the our empirical formula provides a higher precision than the other porosity formulas. When the porosity is between 1.5% and 15%, the acoustic experiment formula can be used not only for acidic volcanics but also in other fractured and vuggy reservoirs, such as intermediate-basic volcanics and weathered dolomite. Moreover, the formula can reduce the effects of borehole enlargement and rock alteration on porosity computation.
基金Financial provided by the National Natural Science Foundation of China (Nos. 51574123 and U1361118)the China Postdoctoral Science Foundation (No. 2015M 582118)
文摘To master theoretical calculation for dust removal efficiency of high pressure atomization in an underground coal mine, the corresponding atomization characteristics and dust removal efficiency were both comprehensively studied in theory by virtue of related theories of hydromechanics and aerosol.According to actual measurements of flow coefficients and atomization angles of X-type swirl nozzle,computational formula was derived for atomized particle sizes of such a nozzle in conjunction with relevant empirical equation. Moreover, a mathematical model for applying high pressure atomization to dust removal in underground coal mine was also established to deduce theoretical computation formula of fractional efficiency. Then, Matlab was adopted to portray the relation curve between fractional efficiency and influence factors. In addition, a theoretical formula was also set up for removal efficiency of respirable dust and total coal dust based on dust size and frequency distribution equations. In the end,impacts of dust characteristic parameters on various dust removal efficiencies were analyzed.
文摘When hitting underground structures directly or exploding in rock-soil media near underground structures, the conventional weapons with large charge weight will make underground structures be subjected to strong shock vibration and cause personal casualty and damage of precision electronic equipments. The shock vibration has become one of the cardinal killing means of weapons. However, the existing methods of predicting structure shock vibration are limited evidently. In this paper the coupling coefficient of acceleration in clayey soil is obtained firstly. Subsequently based on repeated experiments of chemical explosion, after dimension analysis and by using method of multivariate stepwise regression, the calculation formulae of shock vibration acceleration for the underground structure are obtained finally. The formulae consider top and side explosion respectively, taking into account the effects of penetration depth, charge weight, distance to explosion center, rock-soil media, size of structure and buried depth. They are easy to use with high practicability and degree of confidence, and can provide credible evidence for prediction of shock vibration and vibration isolating design of underground structure.
基金Supported by the National Natural Science Foundation of China （20406008）.
文摘Emodin is a kind of anthraquiones with pharmaceutical activities.The solubilities of emodin in ethanol,1-octanol,and ethanol+1-octanol at different temperatures were measured using an analytical method.The solubility of emodin in these solvents increased with an increase in temperature.With the temperature deviating from room temperature,the dependence of the solubility of emodin on temperature became a lot more remarkable.The solubility of emodin in ethanol was more sensitive to temperature than that in 1-octanol.The solubility data of emodin in the same species of solvent at different temperatures was correlated with an empirical equation.The calculated results agreed with the experimental data well.
基金Supported by the Foundation of State Key Laboratory of Autonomous Underwater Vehicle, Harbin Engineering Universitythe Fundamental Research Funds for the Central Universities (HEUCFL20101113)
文摘In order to minimize the harm caused by the instability of a planing craft, a motion prediction model is essential. This paper analyzed the feasibility of using an MGM（1,N） model in grey system theory to predict planing craft motion and carried out the numerical simulation experiment. According to the characteristics of planing craft motion, a recurrence formula was proposed of the parameter matrix of an MGMfl,N） model. Using this formula, data can be updated in real-time without increasing computational complexity significantly. The results of numerical simulation show that using an MGM（1,N） model to predict planing motion is feasible and useful for prediction. So the method proposed in this study can reflect the planing craft motion mechanism successfully, and has rational and effective functions of forecasting and analyzing trends.
