本文介绍基于双光子吸收原理的一种在线自动识别与分拣煤矸石系统。它适用于粒度级别为50～150mm 的矿样,传送带速为≤1m/s,年处理量为120万 t 的矿井。实验表明,分选的准确率可达90%以上.原则上本方法也可适用于粒度级别为20～50mm 的...本文介绍基于双光子吸收原理的一种在线自动识别与分拣煤矸石系统。它适用于粒度级别为50～150mm 的矿样,传送带速为≤1m/s,年处理量为120万 t 的矿井。实验表明,分选的准确率可达90%以上.原则上本方法也可适用于粒度级别为20～50mm 的矿样。展开更多
Optical limiting （OL） properties and two-photon absorption （TPA） of a series of covalently linked graphene oxide-porphyrin composite materials have been investigated by numerically solving the rate equations and f...Optical limiting （OL） properties and two-photon absorption （TPA） of a series of covalently linked graphene oxide-porphyrin composite materials have been investigated by numerically solving the rate equations and field intensity equation with an iterative predictor-corrector finite-difference time-domain technique in nanosecond time domain. Our results show that graphene oxide-porphyrin composites exhibit enhanced OL behavior and possess larger TPA cross section compared with individual porphyrins. Interestingly~ unlike the previous result that porphyrin with heavier central metal shows better nonlinear abilities than that with- out metal substitute, graphene oxide-metal free porphyrin composite has stronger nonlinear absorption properties compared with graphene oxide-metal porphyrin composite. The com- putational results are in reasonable agreement with the experimental ones. Special attention has been paid to the influence of thickness of the medium and pulse width on TPA cross sections, which presents that larger TPA cross sections are obtained as the medium is thicker or the pulse duration is wider.展开更多
基金This work was supported by the 973 program （No.2011CB808100） and the Natural Science Foundation of Shandong Province （No.ZR2014AM026）.
文摘Optical limiting （OL） properties and two-photon absorption （TPA） of a series of covalently linked graphene oxide-porphyrin composite materials have been investigated by numerically solving the rate equations and field intensity equation with an iterative predictor-corrector finite-difference time-domain technique in nanosecond time domain. Our results show that graphene oxide-porphyrin composites exhibit enhanced OL behavior and possess larger TPA cross section compared with individual porphyrins. Interestingly~ unlike the previous result that porphyrin with heavier central metal shows better nonlinear abilities than that with- out metal substitute, graphene oxide-metal free porphyrin composite has stronger nonlinear absorption properties compared with graphene oxide-metal porphyrin composite. The com- putational results are in reasonable agreement with the experimental ones. Special attention has been paid to the influence of thickness of the medium and pulse width on TPA cross sections, which presents that larger TPA cross sections are obtained as the medium is thicker or the pulse duration is wider.
