In order to apply physical simulation results to natural gas hydrate reservoir parameters to provide a theoretical framework for the design of a development plan,an analytical equation method was used to obtain the si...In order to apply physical simulation results to natural gas hydrate reservoir parameters to provide a theoretical framework for the design of a development plan,an analytical equation method was used to obtain the similarity criteria of natural gas hydrate reservoir development by physical simulation,based on a mathematical model of natural gas hydrate development.Given the approach of numerical simulation,a sensitivity analysis for all parameters was carried out,which specifically demonstrated that initial temperature is the most important parameter.Parameters of thermal conductivity coefficients are not necessary for conducting the NGH dissociation process,which will fundamentally simplify the design and establishment of the model.The analysis provides a sound theoretical basis and design principles for particular similarity.展开更多
Data envelopment analysis(DEA) model is widely used to evaluate the relative efficiency of producers. It is a kind of objective decision method with multiple indexes. However, the two basic models frequently used at p...Data envelopment analysis(DEA) model is widely used to evaluate the relative efficiency of producers. It is a kind of objective decision method with multiple indexes. However, the two basic models frequently used at present, the C2R model and the C2GS2 model have limitations when used alone,resulting in evaluations that are often unsatisfactory. In order to solve this problem, a mixed DEA model is built and is used to evaluate the validity of the business efficiency of listed companies. An explanation of how to use this mixed DEA model is offered and its feasibility is verified.展开更多
The noise level of coal face by full-mechanized coal winning technology was measured in a coal mine. And then it was analyzed and evaluated using environment science, ergonomics and fussy mathematics analysis. Basis o...The noise level of coal face by full-mechanized coal winning technology was measured in a coal mine. And then it was analyzed and evaluated using environment science, ergonomics and fussy mathematics analysis. Basis of the statistics and analysis of the measured noise level some measures, such as applying the new materials and improving the construction of the equipment, were carried out. The resuts show that they can reduce the noise level, improve the working environment and enhance the work efficiency.展开更多
In this paper, the vibration characteristics of the structure in the finite fluid domain are analyzed using a coupled finite element method. The added mass matrix is calculated with finite element method （FEM） by 8-...In this paper, the vibration characteristics of the structure in the finite fluid domain are analyzed using a coupled finite element method. The added mass matrix is calculated with finite element method （FEM） by 8-node acoustic fluid elements. The vibration characteristics of the structure in the finite fluid domain are calculated combining structure FEM mass matrix. By writing relevant programs, the numerical analysis on vibration characteristics of a submerged cantilever rectangular plate in finite fluid domain and loaded ship model is performed. A modal identification experiment for the loaded ship model in air and in water is conducted and the experiment results verify the reliability of the numerical analysis. The numerical method can be used for further research on vibration characteristics and acoustic radiation problems of the structure in the finite fluid domain.展开更多
基金supported by the China Petroleum and Chemical Corporation (No.P06070)the National Natural Science Foundation of China (No.50404003)
文摘In order to apply physical simulation results to natural gas hydrate reservoir parameters to provide a theoretical framework for the design of a development plan,an analytical equation method was used to obtain the similarity criteria of natural gas hydrate reservoir development by physical simulation,based on a mathematical model of natural gas hydrate development.Given the approach of numerical simulation,a sensitivity analysis for all parameters was carried out,which specifically demonstrated that initial temperature is the most important parameter.Parameters of thermal conductivity coefficients are not necessary for conducting the NGH dissociation process,which will fundamentally simplify the design and establishment of the model.The analysis provides a sound theoretical basis and design principles for particular similarity.
基金Supported by Commission of Science Technology and Industry for National Defense(No, C192005C001)
文摘Data envelopment analysis(DEA) model is widely used to evaluate the relative efficiency of producers. It is a kind of objective decision method with multiple indexes. However, the two basic models frequently used at present, the C2R model and the C2GS2 model have limitations when used alone,resulting in evaluations that are often unsatisfactory. In order to solve this problem, a mixed DEA model is built and is used to evaluate the validity of the business efficiency of listed companies. An explanation of how to use this mixed DEA model is offered and its feasibility is verified.
文摘The noise level of coal face by full-mechanized coal winning technology was measured in a coal mine. And then it was analyzed and evaluated using environment science, ergonomics and fussy mathematics analysis. Basis of the statistics and analysis of the measured noise level some measures, such as applying the new materials and improving the construction of the equipment, were carried out. The resuts show that they can reduce the noise level, improve the working environment and enhance the work efficiency.
基金Supported by the National Natural Science Foundation of China （No. 51079027）.
文摘In this paper, the vibration characteristics of the structure in the finite fluid domain are analyzed using a coupled finite element method. The added mass matrix is calculated with finite element method （FEM） by 8-node acoustic fluid elements. The vibration characteristics of the structure in the finite fluid domain are calculated combining structure FEM mass matrix. By writing relevant programs, the numerical analysis on vibration characteristics of a submerged cantilever rectangular plate in finite fluid domain and loaded ship model is performed. A modal identification experiment for the loaded ship model in air and in water is conducted and the experiment results verify the reliability of the numerical analysis. The numerical method can be used for further research on vibration characteristics and acoustic radiation problems of the structure in the finite fluid domain.
