The cumulative blasting using PVC slotting pipe was tested for rapid driving in hard-rock roadway construction. First, the outhors optimized blasting parameters on 2.2 m scheme, and did both-sides comparative experime...The cumulative blasting using PVC slotting pipe was tested for rapid driving in hard-rock roadway construction. First, the outhors optimized blasting parameters on 2.2 m scheme, and did both-sides comparative experiment of the surrounding holes after the blasting success. The results show that the application of slotting tube obtains four more cut contours than the case without it. Finally we did full-section control and non-control blasting comparative experiment, the results show that the rates of half-hole marks and the non-smooth grades of the cut contours can reach 95%, hole spacing is expanded to larger than 550 mm, and 550 mm is the best under the K2 limestone conditions.展开更多
The beam deflectors based on electro-optic phased array（EOPA） is mainly described, and then an analysis on existing control schemes for driving the EOPA beam deflectors, based on custom hard-wired electronics or bas...The beam deflectors based on electro-optic phased array（EOPA） is mainly described, and then an analysis on existing control schemes for driving the EOPA beam deflectors, based on custom hard-wired electronics or based on software in a microcontroUer, is made. Compared with these, a driving and control system for a multi-channel EOPA beam deflector is presented, in which the control assignment is implemented with a field programmable gate array（FPGA） chip. For different performance requirements, two control schemes, one with the serial scheme and another with the parallel scheme, have been explored and rapidly prototyped in Xilinx FPGA chips. With the control structures for the EOPA beam deflector, scanning rates of 588 kHz and 5 MHz can be respectivelv reached.展开更多
文摘The cumulative blasting using PVC slotting pipe was tested for rapid driving in hard-rock roadway construction. First, the outhors optimized blasting parameters on 2.2 m scheme, and did both-sides comparative experiment of the surrounding holes after the blasting success. The results show that the application of slotting tube obtains four more cut contours than the case without it. Finally we did full-section control and non-control blasting comparative experiment, the results show that the rates of half-hole marks and the non-smooth grades of the cut contours can reach 95%, hole spacing is expanded to larger than 550 mm, and 550 mm is the best under the K2 limestone conditions.
基金National Natural Science Foundation of China(60477042)
文摘The beam deflectors based on electro-optic phased array（EOPA） is mainly described, and then an analysis on existing control schemes for driving the EOPA beam deflectors, based on custom hard-wired electronics or based on software in a microcontroUer, is made. Compared with these, a driving and control system for a multi-channel EOPA beam deflector is presented, in which the control assignment is implemented with a field programmable gate array（FPGA） chip. For different performance requirements, two control schemes, one with the serial scheme and another with the parallel scheme, have been explored and rapidly prototyped in Xilinx FPGA chips. With the control structures for the EOPA beam deflector, scanning rates of 588 kHz and 5 MHz can be respectivelv reached.
