Natural geological structures in rock(e.g.,joints,weakness planes,defects)play a vital role in the stability of tunnels and underground operations during construction.We investigated the failure characteristics of a d...Natural geological structures in rock(e.g.,joints,weakness planes,defects)play a vital role in the stability of tunnels and underground operations during construction.We investigated the failure characteristics of a deep circular tunnel in a rock mass with multiple weakness planes using a 2D combined finite element method/discrete element method(FEM/DEM).Conventional triaxial compression tests were performed on typical hard rock(marble)specimens under a range of confinement stress conditions to validate the rationale and accuracy of the proposed numerical approach.Parametric analysis was subsequently conducted to investigate the influence of inclination angle,and length on the crack propagation behavior,failure mode,energy evolution,and displacement distribution of the surrounding rock.The results show that the inclination angle strongly affects tunnel stability,and the failure intensity and damage range increase with increasing inclination angle and then decrease.The dynamic disasters are more likely with increasing weak plane length.Shearing and sliding along multiple weak planes are also consistently accompanied by kinetic energy fluctuations and surges after unloading,which implies a potentially violent dynamic response around a deeply-buried tunnel.Interactions between slabbing and shearing near the excavation boundaries are also discussed.The results presented here provide important insight into deep tunnel failure in hard rock influenced by both unloading disturbance and tectonic activation.展开更多
The coherent control of molecular alignment and orientation by a femtosecond two-color laser pulse is studied theoretically.The effect of the carrier-envelope phase of the femtosecond two-color laser pulse on molecula...The coherent control of molecular alignment and orientation by a femtosecond two-color laser pulse is studied theoretically.The effect of the carrier-envelope phase of the femtosecond two-color laser pulse on molecular alignment and orientation is discussed,and it is shown that the enhancement or suppression of the molecular orientation can be coherently manipulated by precisely controlling the carrier-envelope phase of the femtosecond two-color laser pulse.In addition,the time-dependent angular distributions of the molecular axis are presented.展开更多
We investigate the quantum interference of spin wave excitations of a spin-1 atomic Bose condensate confined in an optical lattice. Single-channel and dual-channel interactions are employed in our system, and their in...We investigate the quantum interference of spin wave excitations of a spin-1 atomic Bose condensate confined in an optical lattice. Single-channel and dual-channel interactions are employed in our system, and their induced excitations are compared. Also we consider the interplay of magneto-optical excitations, which leads to a constructive or destructive effect for the creation of magnons based on background excitations. The population distributions of excited magnons can be well controlled by steering the long-range dipole-dipole interactions. Such a scheme can be used to demonstrate conventional quantum-optical phenomena like dynamical Casimir effect at finite temperatures.展开更多
基金Projects(52004143,51774194)supported by the National Natural Science Foundation of ChinaProject(2020M670781)supported by the China Postdoctoral Science Foundation+2 种基金Project(SKLGDUEK2021)supported by the State Key Laboratory for GeoMechanics and Deep Underground Engineering,ChinaProject(U1806208)supported by the NSFC-Shandong Joint Fund,ChinaProject(2018GSF117023)supported by the Key Research and Development Program of Shandong Province,China。
文摘Natural geological structures in rock(e.g.,joints,weakness planes,defects)play a vital role in the stability of tunnels and underground operations during construction.We investigated the failure characteristics of a deep circular tunnel in a rock mass with multiple weakness planes using a 2D combined finite element method/discrete element method(FEM/DEM).Conventional triaxial compression tests were performed on typical hard rock(marble)specimens under a range of confinement stress conditions to validate the rationale and accuracy of the proposed numerical approach.Parametric analysis was subsequently conducted to investigate the influence of inclination angle,and length on the crack propagation behavior,failure mode,energy evolution,and displacement distribution of the surrounding rock.The results show that the inclination angle strongly affects tunnel stability,and the failure intensity and damage range increase with increasing inclination angle and then decrease.The dynamic disasters are more likely with increasing weak plane length.Shearing and sliding along multiple weak planes are also consistently accompanied by kinetic energy fluctuations and surges after unloading,which implies a potentially violent dynamic response around a deeply-buried tunnel.Interactions between slabbing and shearing near the excavation boundaries are also discussed.The results presented here provide important insight into deep tunnel failure in hard rock influenced by both unloading disturbance and tectonic activation.
基金Supported by the National Natural Science Foundation of China under Grant Nos 60977063,61077037 and 11274096the Doctoral Research Fund of Henan Normal University under Grant No qd12109.
文摘The coherent control of molecular alignment and orientation by a femtosecond two-color laser pulse is studied theoretically.The effect of the carrier-envelope phase of the femtosecond two-color laser pulse on molecular alignment and orientation is discussed,and it is shown that the enhancement or suppression of the molecular orientation can be coherently manipulated by precisely controlling the carrier-envelope phase of the femtosecond two-color laser pulse.In addition,the time-dependent angular distributions of the molecular axis are presented.
基金Supported by the National Basic Research Program of China (973 Program) under Grant No. 2011CB921604+4 种基金the National Natural Science Foundation of China under Grant Nos. 11004057, 10828408Educational Commission of Henan Province of China under Grant No. 01026631082the “Chen Guang” Project Supported by Shanghai Municipal Education Commission and Shanghai Education Development Foundation under Grant No.10CG24
文摘We investigate the quantum interference of spin wave excitations of a spin-1 atomic Bose condensate confined in an optical lattice. Single-channel and dual-channel interactions are employed in our system, and their induced excitations are compared. Also we consider the interplay of magneto-optical excitations, which leads to a constructive or destructive effect for the creation of magnons based on background excitations. The population distributions of excited magnons can be well controlled by steering the long-range dipole-dipole interactions. Such a scheme can be used to demonstrate conventional quantum-optical phenomena like dynamical Casimir effect at finite temperatures.
