The mechanism of stress generation and propagation by detonation loading in five separate independent advance of ore breaking patterns is discussed in the paper. An elastic numerical model was developed using AN- SYS/...The mechanism of stress generation and propagation by detonation loading in five separate independent advance of ore breaking patterns is discussed in the paper. An elastic numerical model was developed using AN- SYS/LS-DYNA 3D Nonlinear Dynamic Finite Element Software. In this package ANSYS is the preprocessor and LS-DYNA is the postprocessor. Numerical models in the paper to actual were l：10 and the element mesh was dissected in scanning mode utilizing the symmetry characteristics of the numerical model. Five different advance rates were studied. Parameters, such as the time required to maximum stress, the action time of the available stress, the maximum velocity of the nodes, the stress penetration time, the magnitude of the stress peak and the time duration for high stress were numerically simulated. The 2.2 m advance appeared optimum from an analysis of the simulation results. The results from numerical simulation have been validated by tests with physical models.展开更多
The two-photon polarized entangled state is generated from the typeⅡspontaneous parametric down-conversion pumped by a femtosecond pulse.The two-photon interference is observed in the Hong-Ou-Mandel interferometer.Th...The two-photon polarized entangled state is generated from the typeⅡspontaneous parametric down-conversion pumped by a femtosecond pulse.The two-photon interference is observed in the Hong-Ou-Mandel interferometer.The high visibility of the interference is restored with narrow band interference filters placed in front of the detectors.展开更多
We report a fourth-order interference experiment in which pairs of photons are produced in spontaneous parametric down-conversion pumped by femtosecond pulses interfere in a Hong-Ou-Mandel interferometer.The visibilit...We report a fourth-order interference experiment in which pairs of photons are produced in spontaneous parametric down-conversion pumped by femtosecond pulses interfere in a Hong-Ou-Mandel interferometer.The visibilityof the interference is(64±4)%,exceeding the bound of 50%predicted by classical interference theory.展开更多
Volume compensation(VC)achieved in(Lu,Nd):YAl_(3)(BO_(3))_(4)(YAB)crystal codoped with Lu^(3+)and Nd^(3+)ions is described.The lattice parameters,spectral properties and laser performances of the VC(Lu,Nd):YAB and sin...Volume compensation(VC)achieved in(Lu,Nd):YAl_(3)(BO_(3))_(4)(YAB)crystal codoped with Lu^(3+)and Nd^(3+)ions is described.The lattice parameters,spectral properties and laser performances of the VC(Lu,Nd):YAB and single-doped Nd:YAB(NYAB)crystals are measured and compared.The results indicate that the laser performances of NYAB crystal can be greatly improved by the VC doping.展开更多
文摘The mechanism of stress generation and propagation by detonation loading in five separate independent advance of ore breaking patterns is discussed in the paper. An elastic numerical model was developed using AN- SYS/LS-DYNA 3D Nonlinear Dynamic Finite Element Software. In this package ANSYS is the preprocessor and LS-DYNA is the postprocessor. Numerical models in the paper to actual were l：10 and the element mesh was dissected in scanning mode utilizing the symmetry characteristics of the numerical model. Five different advance rates were studied. Parameters, such as the time required to maximum stress, the action time of the available stress, the maximum velocity of the nodes, the stress penetration time, the magnitude of the stress peak and the time duration for high stress were numerically simulated. The 2.2 m advance appeared optimum from an analysis of the simulation results. The results from numerical simulation have been validated by tests with physical models.
基金Supported by the National Natural Science Foundation of China under Grant No.19874056the National Natural Science Foundation for Youth of China under Grant No.69907005。
文摘The two-photon polarized entangled state is generated from the typeⅡspontaneous parametric down-conversion pumped by a femtosecond pulse.The two-photon interference is observed in the Hong-Ou-Mandel interferometer.The high visibility of the interference is restored with narrow band interference filters placed in front of the detectors.
基金Supported by National Natural Science Foundation of China(Grant No.19874056)National Natural Science Foundation of China for Youth(Grant No.69907005).
文摘We report a fourth-order interference experiment in which pairs of photons are produced in spontaneous parametric down-conversion pumped by femtosecond pulses interfere in a Hong-Ou-Mandel interferometer.The visibilityof the interference is(64±4)%,exceeding the bound of 50%predicted by classical interference theory.
基金Supported by the National Natural Science Foundation of China.
文摘Volume compensation(VC)achieved in(Lu,Nd):YAl_(3)(BO_(3))_(4)(YAB)crystal codoped with Lu^(3+)and Nd^(3+)ions is described.The lattice parameters,spectral properties and laser performances of the VC(Lu,Nd):YAB and single-doped Nd:YAB(NYAB)crystals are measured and compared.The results indicate that the laser performances of NYAB crystal can be greatly improved by the VC doping.
