Infrasonic Passive Differential Spectroscopy (IPDS) technology is employed for direct detection of hydrocarbons.Low-frequency seismic gives geophysicists a new seismic imaging technique to look into wealth & healt...Infrasonic Passive Differential Spectroscopy (IPDS) technology is employed for direct detection of hydrocarbons.Low-frequency seismic gives geophysicists a new seismic imaging technique to look into wealth & health of reservoir.Hydrocarbon reservoirs can be the origin of a continuous source of low-frequency seismic waves.These phenomena are sometimes called"hydrocarbon microtremors".Low-frequ-展开更多
Objective:To reveal the neural network of active and passive hand movements. Method:Seven healthy aged people were checked, and acquired functional magnetic resonance imaging data on a 1.5T scanner. Active movement co...Objective:To reveal the neural network of active and passive hand movements. Method:Seven healthy aged people were checked, and acquired functional magnetic resonance imaging data on a 1.5T scanner. Active movement consisted of repetitive grasping and loosening of hand; passive movement involved the same movement performed by examiner. Both types of hand movements were assessed separately. These data were analysed by Statistical Parametric Mapping Microsoft. Result:The main activated brain areas were the contralateral supplemental motor area, primary motor area, primary sensory area and the ipsilateral cerebellum when subjects gripped right hands actively and passively. The supplemental area was less active in passive hand movement than active hand movement. The activated brain areas were mainly within Brodmann area 4 during active hand movement; in the contrast, the voxels triggered by passive movement were mainly within Brodmann areas 3,1,2 areas. Conclusion:The results suggest that the neural networks of passive and active tasks spared some common areas, and the passive movement could be as effective as active movement to facilitate the recovery of limbs motor function in patients with brain damage.展开更多
The main object of this paper is the mathematical study of the vibration behavior in ultrasonic machining (USM) described by non-linear differential equations. The ultrasonic machining (USM) consists of the tool holde...The main object of this paper is the mathematical study of the vibration behavior in ultrasonic machining (USM) described by non-linear differential equations. The ultrasonic machining (USM) consists of the tool holder and the absor-bers representing the tools. This leads to four-degree-of-freedom system subject to multi-external excitation forces. The aim of this project is the reduction of the vibrations in the tool holder and have reasonable amplitudes for the tools represented by the multi-absorbers. Multiple scale perturbation method is applied to obtain the solution up to the second order approximation and to study the stability of the steady state solution near different simultaneous resonance cases. The resulting different resonance cases are reported and studied numerically. The stability of the steady state solution near the selected resonance cases is studied applying both frequency response equations and phase-plane technique. The effects of the different parameters of the system and the absorbers on the system behavior are studied numerically. Optimum working conditions for the tools were obtained. Comparison with the available published work is reported.展开更多
文摘Infrasonic Passive Differential Spectroscopy (IPDS) technology is employed for direct detection of hydrocarbons.Low-frequency seismic gives geophysicists a new seismic imaging technique to look into wealth & health of reservoir.Hydrocarbon reservoirs can be the origin of a continuous source of low-frequency seismic waves.These phenomena are sometimes called"hydrocarbon microtremors".Low-frequ-
基金supported by the Key Projects of Shanghai Science and Technology on Biomedicine(NO.10DZ1950800)the Major Project of Shanghai Zhabei District Health Bureau (No. 2011ZD01)
文摘Objective:To reveal the neural network of active and passive hand movements. Method:Seven healthy aged people were checked, and acquired functional magnetic resonance imaging data on a 1.5T scanner. Active movement consisted of repetitive grasping and loosening of hand; passive movement involved the same movement performed by examiner. Both types of hand movements were assessed separately. These data were analysed by Statistical Parametric Mapping Microsoft. Result:The main activated brain areas were the contralateral supplemental motor area, primary motor area, primary sensory area and the ipsilateral cerebellum when subjects gripped right hands actively and passively. The supplemental area was less active in passive hand movement than active hand movement. The activated brain areas were mainly within Brodmann area 4 during active hand movement; in the contrast, the voxels triggered by passive movement were mainly within Brodmann areas 3,1,2 areas. Conclusion:The results suggest that the neural networks of passive and active tasks spared some common areas, and the passive movement could be as effective as active movement to facilitate the recovery of limbs motor function in patients with brain damage.
文摘The main object of this paper is the mathematical study of the vibration behavior in ultrasonic machining (USM) described by non-linear differential equations. The ultrasonic machining (USM) consists of the tool holder and the absor-bers representing the tools. This leads to four-degree-of-freedom system subject to multi-external excitation forces. The aim of this project is the reduction of the vibrations in the tool holder and have reasonable amplitudes for the tools represented by the multi-absorbers. Multiple scale perturbation method is applied to obtain the solution up to the second order approximation and to study the stability of the steady state solution near different simultaneous resonance cases. The resulting different resonance cases are reported and studied numerically. The stability of the steady state solution near the selected resonance cases is studied applying both frequency response equations and phase-plane technique. The effects of the different parameters of the system and the absorbers on the system behavior are studied numerically. Optimum working conditions for the tools were obtained. Comparison with the available published work is reported.
