Search

In order to explore the thermodynamic mechanism of multicomponent gas adsorption on coal, the Grand Canonical Monte Carlo simulation method was used to study the adsorption behavior of CH4, CO2 and N2 in the coal molecular model at different temperatures from the perspective of thermodynamics. The simu-lation results show that CH4 shows a dotted distribution, CO2 shows a cluster distribution, and N2 shows a strip distribution in the unit cell. The relationship between the adsorption capacity, adsorption heat and adsorption entropy of the three gases is CO2> CH4> N2. And the relationship between the adsorption potential of the three gases is CO2

To study the force characteristics of support boots of a shearer under the conditions of large span and over constraint,the static model of the shearer under 18 loads was established by considering the factors including the roll and pitch angles.Aiming at the uncertainty of model coefficient matrix,an improved aggregation function was proposed to deal with the absolute coefficient matrix of the shearer static equations,and the modified smooth nonlinear equations were obtained.The three-axis forces of the drum obtained by the cutting experiment were input into the static equations as the excitation,the Levenberg-Marguardt method was used to solve the equations,and the theoretical values of boots were calculated and compared with the actual measured values.According to the error range less than 10%,the correctness of the theoretical model was verified.By applying the control variable method,the roll and pitch angles of the shearer were changed respectively to research the force characteristics variation of the shearer boots.The results show that the influences of the roll angle variation to the lateral forces of the front and rear guiding sliding boots were bigger,and to the support forces of the front and rear sliding boots and the flat sliding boots were smaller.The forces of all boots were influenced by the shearer roll angle variation,and the force variations were approximately linear. [ABSTRACT FROM AUTHOR]

To study the mechanics and permeability characteristics of similar material of solid-gas coupling, orthogonal test is used to make up similar material which using river sand as aggregate, paraffin as cementing agent and hydraulic oil as regulator. Adopting range analysis and multivariate regression analysis, the influence of impact number, aggregate size, oil content and cement-sand ratio on the compressive strength, elasticity modulus, Poisson's ratio and permeability of similar material are investigated. The test results show that the size order that factors against compressive strength is oil content, impact number, aggregate size, and cement-sand ratio. The size order that factors against elasticity modulus is oil content,impact number, cement-sand ratio and aggregate size. The size order against permeability is impact number, cement-sand ratio, oil content and aggregate size.The factors have less influence on Poisson's ratio. The compressive strength and elasticity modulus of similar material is positively related to impact number and aggregate size, and is negatively related to oil content and cement-sand ratio. The permeability is negatively related to impact number, aggregate size, oil content, and is positively related to cement-sand ratio. Poisson's ratio has no obvious relationship with the factors. The comprehensive model of characteristic parameters of similar material is obtained under the influence of four factors in test. [ABSTRACT FROM AUTHOR]