This study, based on the physico\|chemistry principle, establishes the mathematics model of the genesis of plagioclase oscillatory zoning. Based on the crystal growth principle, the plagioclase crystallization velocit...This study, based on the physico\|chemistry principle, establishes the mathematics model of the genesis of plagioclase oscillatory zoning. Based on the crystal growth principle, the plagioclase crystallization velocity equation has been put forward. This equation has such a feedback character as \!supersaturation—nucleation—depletion cycle". Small\|scale oscillatory zoning is attributable to self\|organization, and has no bearing on environmental factors. Its genesis is corresponding to a relatively static environment.展开更多
Determination of probable mechanism function and kinetic parameters is important to hydrometallurgical kinetics.In this work,the most probable mechanism function and kinetic parameters of gibbsite dissolution in NaOH ...Determination of probable mechanism function and kinetic parameters is important to hydrometallurgical kinetics.In this work,the most probable mechanism function and kinetic parameters of gibbsite dissolution in NaOH solution are studied.The sample,the mixture of synthetic gibbsite and sodium hydroxide solution,was scanned in high-pressure differential scanning calorimetry(DSC) equipment with the heating rate of 10 K·min-1. Integral equation and differential equation of non-isothermal kinetics were solved to fit the data related to DSC curve.According to the calculation results,the most probable mechanism function for pure synthetic gibbsite dissolution in sodium hydroxide solution is presented based on the optimum procedure in the database of the mechanism function.The apparent activation energy obtained is(75±1) kJ·mol-1,the frequency factor is 10 8±1mol·s-1,and the reaction is a second order reaction.展开更多
The development of notions about the mechanism of the oxidative coupling of methane （OCM） over oxide catalysts and corresponding progress in its kinetic description are reviewed and discussed. The latter becomes ess...The development of notions about the mechanism of the oxidative coupling of methane （OCM） over oxide catalysts and corresponding progress in its kinetic description are reviewed and discussed. The latter becomes essential at the stage of scaling up and optimization of the process in pilot and industrial reactors. It is demonstrated that the main achievements in the development of kinetic models can be reached by combining the approaches conventionally used in homogeneous gas-phase kinetics and in heterogeneous catalysis. In particular, some important features of the OCM process can be described if several elementary reactions of free radical species （formation and transformation） with surface active sites are included into the detailed scheme of methane oxidation in gas. However, some important features, such as a non-additive character of the reciprocal influence of methane and ethane in the case of their simultaneous presence in the reaction mixture, cannot yet be described and comprehended in the framework of schemes developed so far. Possible ways towards an advanced kinetic model, accounting the main principles of catalyst functioning （redox nature of active sites） and pathways of product formation （via free radicals） are traced.展开更多
The study of physical systems endowed with a position-dependent mass (PDM) remains a fundamental issue of quantum mechanics. In this paper we use a new approach, recently developed by us for building the quantum kinet...The study of physical systems endowed with a position-dependent mass (PDM) remains a fundamental issue of quantum mechanics. In this paper we use a new approach, recently developed by us for building the quantum kinetic energy operator (KEO) within the Schrodinger equation, in order to construct a new class of exactly solvable models with a position varying mass, presenting a harmonic-oscillator-like spectrum. To do so we utilize the formalism of supersymmetric quantum mechanics (SUSY QM) along with the shape invariance condition. Recent outcomes of non-Hermitian quantum mechanics are also taken into account.展开更多
针对井下巷道支护人工打锚索安全性差且效率低的问题,锚杆钻机设计新增了锚杆机械臂。根据机械臂的实际尺寸建立了三维模型,并且以机器臂设计运动学理论为基础,推导出锚杆钻机机械臂动力学方程。由于锚杆钻机机械臂在实际运动下受力相...针对井下巷道支护人工打锚索安全性差且效率低的问题,锚杆钻机设计新增了锚杆机械臂。根据机械臂的实际尺寸建立了三维模型,并且以机器臂设计运动学理论为基础,推导出锚杆钻机机械臂动力学方程。由于锚杆钻机机械臂在实际运动下受力相对复杂,并且对整机稳定性有较大的影响,故将机器臂的虚拟样机模型导入多体动力学软件ADAMS中进行动力学仿真,观察钻架在恒定外负载作用下,通过调整两个油缸之间的行程是否能实现钻架在整个工作空间的所有工作位置,找到整机在不同姿态打锚索时的最恶劣工况,查看该工况下油缸受力变化及伸缩臂受力状况。在仿真时刻3s时,机械臂升降油缸受力超过该油缸的许用极限抗压力1.9×10~5 N,需要运用Ansys Work Bench对伸缩臂承受扭转力较大处进行扭转静强度校核,以保证机械臂的动力学需求,为日后"工业机械臂"动力学分析提供一定的理论基础和实践经验。展开更多
文摘This study, based on the physico\|chemistry principle, establishes the mathematics model of the genesis of plagioclase oscillatory zoning. Based on the crystal growth principle, the plagioclase crystallization velocity equation has been put forward. This equation has such a feedback character as \!supersaturation—nucleation—depletion cycle". Small\|scale oscillatory zoning is attributable to self\|organization, and has no bearing on environmental factors. Its genesis is corresponding to a relatively static environment.
基金Supported by the Research Fund for the Doctoral Program of Higher Education(20050145029)the Science and Technology Talents Fund for Excellent Youth of Liaoning Province(2005221012)
文摘Determination of probable mechanism function and kinetic parameters is important to hydrometallurgical kinetics.In this work,the most probable mechanism function and kinetic parameters of gibbsite dissolution in NaOH solution are studied.The sample,the mixture of synthetic gibbsite and sodium hydroxide solution,was scanned in high-pressure differential scanning calorimetry(DSC) equipment with the heating rate of 10 K·min-1. Integral equation and differential equation of non-isothermal kinetics were solved to fit the data related to DSC curve.According to the calculation results,the most probable mechanism function for pure synthetic gibbsite dissolution in sodium hydroxide solution is presented based on the optimum procedure in the database of the mechanism function.The apparent activation energy obtained is(75±1) kJ·mol-1,the frequency factor is 10 8±1mol·s-1,and the reaction is a second order reaction.
文摘The development of notions about the mechanism of the oxidative coupling of methane （OCM） over oxide catalysts and corresponding progress in its kinetic description are reviewed and discussed. The latter becomes essential at the stage of scaling up and optimization of the process in pilot and industrial reactors. It is demonstrated that the main achievements in the development of kinetic models can be reached by combining the approaches conventionally used in homogeneous gas-phase kinetics and in heterogeneous catalysis. In particular, some important features of the OCM process can be described if several elementary reactions of free radical species （formation and transformation） with surface active sites are included into the detailed scheme of methane oxidation in gas. However, some important features, such as a non-additive character of the reciprocal influence of methane and ethane in the case of their simultaneous presence in the reaction mixture, cannot yet be described and comprehended in the framework of schemes developed so far. Possible ways towards an advanced kinetic model, accounting the main principles of catalyst functioning （redox nature of active sites） and pathways of product formation （via free radicals） are traced.
基金The authors gratefully acknowledge Qassim University,represented by the Deanship of Scienti c Research,on the material support for this research under the number(1671-ALRASSCAC-2016-1-12-S)during the academic year 1437 AH/2016 AD.
文摘The study of physical systems endowed with a position-dependent mass (PDM) remains a fundamental issue of quantum mechanics. In this paper we use a new approach, recently developed by us for building the quantum kinetic energy operator (KEO) within the Schrodinger equation, in order to construct a new class of exactly solvable models with a position varying mass, presenting a harmonic-oscillator-like spectrum. To do so we utilize the formalism of supersymmetric quantum mechanics (SUSY QM) along with the shape invariance condition. Recent outcomes of non-Hermitian quantum mechanics are also taken into account.
文摘针对井下巷道支护人工打锚索安全性差且效率低的问题,锚杆钻机设计新增了锚杆机械臂。根据机械臂的实际尺寸建立了三维模型,并且以机器臂设计运动学理论为基础,推导出锚杆钻机机械臂动力学方程。由于锚杆钻机机械臂在实际运动下受力相对复杂,并且对整机稳定性有较大的影响,故将机器臂的虚拟样机模型导入多体动力学软件ADAMS中进行动力学仿真,观察钻架在恒定外负载作用下,通过调整两个油缸之间的行程是否能实现钻架在整个工作空间的所有工作位置,找到整机在不同姿态打锚索时的最恶劣工况,查看该工况下油缸受力变化及伸缩臂受力状况。在仿真时刻3s时,机械臂升降油缸受力超过该油缸的许用极限抗压力1.9×10~5 N,需要运用Ansys Work Bench对伸缩臂承受扭转力较大处进行扭转静强度校核,以保证机械臂的动力学需求,为日后"工业机械臂"动力学分析提供一定的理论基础和实践经验。
