A possibility of the efficient use of rotary percussive drilling to provide drilling smaller diameter holes(40–70 mm) both in mining and prospecting is disclosed herein. A new construction designed for the nipple thr...A possibility of the efficient use of rotary percussive drilling to provide drilling smaller diameter holes(40–70 mm) both in mining and prospecting is disclosed herein. A new construction designed for the nipple thread connection is described. The relative amplitude variation, change of power pulse time and energy in their propagation throughout the drilling tool are determined. A possibility of the efficient power pulse transfer along the drill string to the rock destruction tools with new nipple connections which allow automating the make-up and breakout system of drill pipe was supported by experiments.展开更多
A quantum dynamic calculation on a five-dimensional O2/LiF （001） model system is performed using themulti-configuration time-dependent Hartree method.The obtained results show that the mechanism of rotational anddif...A quantum dynamic calculation on a five-dimensional O2/LiF （001） model system is performed using themulti-configuration time-dependent Hartree method.The obtained results show that the mechanism of rotational anddiffractive excitation in details: Comparison with the rotational excited state, the initially non-rotational state is seento favor the inelastic scattering in the rotational excitation process.The surface corrugation can damp the quantuminterferences and produce a greater amount of rotational inelastic scattering at the expense of the elastic process inthe rotational excitation process.The diffraction process and the average energy transferred into the rotational anddiffractive mode are also discussed.展开更多
A general and efficient method is presented in this paper for studying the effects of unbalance on the breathing mechanism of crack.Based on 3D finite element models combined with a nonlinear contact approach for crac...A general and efficient method is presented in this paper for studying the effects of unbalance on the breathing mechanism of crack.Based on 3D finite element models combined with a nonlinear contact approach for crack modeling, the method is free from theassumption of weight-dominance and can be used to gain deep insights into the breathing mechanism of crack. In order to greatlyreduce the computational time, a complex free-interface component mode synthesis (CMS) method is employed to reduce theorder of the model. Based on the proposed method, the effects of unbalance on the breathing mechanism of crack are discussed.Numerical results show that the unbalance can lead to significant changes in the breathing of crack, even when the unbalance force is about an order of magnitude smaller than the self-weight. Moreover, the level and orientation of the unbalance have also remarkable effects on the breathing behaviors of crack. Besides, a new universal non-steady breathing phenomenon of crack is firstly found in this paper, which denotes that the breathing speed of a crack is fluctuated over one revolution when there exists residual unbalance in the cracked rotor.展开更多
基金supported by the research Grant within the framework of the Federal Target Program ‘Scientific and Academic Staff of Innovative Russia’ during the years of 2009–2013competitive activity 1.3.1. ‘Research conducted by young researchers, Ph.D. holders’, the project theme ‘Research of power pulse interaction in a drilling tool and in rock mass in underground borehole drilling’
文摘A possibility of the efficient use of rotary percussive drilling to provide drilling smaller diameter holes(40–70 mm) both in mining and prospecting is disclosed herein. A new construction designed for the nipple thread connection is described. The relative amplitude variation, change of power pulse time and energy in their propagation throughout the drilling tool are determined. A possibility of the efficient power pulse transfer along the drill string to the rock destruction tools with new nipple connections which allow automating the make-up and breakout system of drill pipe was supported by experiments.
基金Support by the National Natural Science Foundation of China under Grant No.10776022 the Specialized Research Fund for the Doctoral Program of Higher Education under Grant No.20090181110080
文摘A quantum dynamic calculation on a five-dimensional O2/LiF （001） model system is performed using themulti-configuration time-dependent Hartree method.The obtained results show that the mechanism of rotational anddiffractive excitation in details: Comparison with the rotational excited state, the initially non-rotational state is seento favor the inelastic scattering in the rotational excitation process.The surface corrugation can damp the quantuminterferences and produce a greater amount of rotational inelastic scattering at the expense of the elastic process inthe rotational excitation process.The diffraction process and the average energy transferred into the rotational anddiffractive mode are also discussed.
基金supported by the Project of National Natural Science Foundation of China for Innovation Research Group (Grant No. 51421004)the National Natural Science Foundation of China (Grant No. 51275384)China Postdoctoral Science Foundation (Grant No. 2014M560765)
文摘A general and efficient method is presented in this paper for studying the effects of unbalance on the breathing mechanism of crack.Based on 3D finite element models combined with a nonlinear contact approach for crack modeling, the method is free from theassumption of weight-dominance and can be used to gain deep insights into the breathing mechanism of crack. In order to greatlyreduce the computational time, a complex free-interface component mode synthesis (CMS) method is employed to reduce theorder of the model. Based on the proposed method, the effects of unbalance on the breathing mechanism of crack are discussed.Numerical results show that the unbalance can lead to significant changes in the breathing of crack, even when the unbalance force is about an order of magnitude smaller than the self-weight. Moreover, the level and orientation of the unbalance have also remarkable effects on the breathing behaviors of crack. Besides, a new universal non-steady breathing phenomenon of crack is firstly found in this paper, which denotes that the breathing speed of a crack is fluctuated over one revolution when there exists residual unbalance in the cracked rotor.
