We report on the properties of strong pulses from PSR B0656＋14 by analyzing the data obtained using the Urumqi 25-m radio telescope at 1540 MHz from August 2007 to September 2010.In 44 h of observational data,a total...We report on the properties of strong pulses from PSR B0656＋14 by analyzing the data obtained using the Urumqi 25-m radio telescope at 1540 MHz from August 2007 to September 2010.In 44 h of observational data,a total of 67 pulses with signal-to-noise ratios above a 5σthreshold were detected.The peak flux densities of these pulses are 58 to 194 times that of the average profile,and their pulse energies are 3 to 68 times that of the average pulse.These pulses are clustered around phases about 5-ahead of the peak of the average profile.Compared with the width of the average profile,they are relatively narrow,with the full widths at half-maximum ranging from 0.28 ° to 1.78 °.The distribution of pulse-energies follows a lognormal distribution.These sporadic strong pulses detected from PSR B0656＋14 have different characteristics from both typical giant pulses and its regular pulses.展开更多
Previous work showed that pulse-laser irradiation can strengthen metal multilayer thin films through intermetallic formation and the degree of strengthening is a function of laser pulse energy.In this work,the effect ...Previous work showed that pulse-laser irradiation can strengthen metal multilayer thin films through intermetallic formation and the degree of strengthening is a function of laser pulse energy.In this work,the effect of individual layer thickness(λ)and total multilayer thickness(h)on the resulting microstructure and mechanical strength of laser-treated Ti/Ni multilayers was further investigated.Experiments were carried out on fourλ/hcombinations using individual layer thickness of 20 nm and 50 nm,and total multilayer thickness of 500 nm and1μm,respectively.Obvious intermetallic strengthening was observed in the 500 nm thick multilayers,especially with the 20 nm layer thickness,but not in the 1μm thick multilayers.Further,the multilayer surface morphology after laser treatment was observed to be dominated by competition between laser-induced optical interference and thermal melting,with the former leading to ripple or cross-hatched patterns and the latter leading to melted surfaces with pores and cracks.展开更多
基金funded by the National Natural Science Foundation of China(Grant No.10973026)
文摘We report on the properties of strong pulses from PSR B0656＋14 by analyzing the data obtained using the Urumqi 25-m radio telescope at 1540 MHz from August 2007 to September 2010.In 44 h of observational data,a total of 67 pulses with signal-to-noise ratios above a 5σthreshold were detected.The peak flux densities of these pulses are 58 to 194 times that of the average profile,and their pulse energies are 3 to 68 times that of the average pulse.These pulses are clustered around phases about 5-ahead of the peak of the average profile.Compared with the width of the average profile,they are relatively narrow,with the full widths at half-maximum ranging from 0.28 ° to 1.78 °.The distribution of pulse-energies follows a lognormal distribution.These sporadic strong pulses detected from PSR B0656＋14 have different characteristics from both typical giant pulses and its regular pulses.
文摘Previous work showed that pulse-laser irradiation can strengthen metal multilayer thin films through intermetallic formation and the degree of strengthening is a function of laser pulse energy.In this work,the effect of individual layer thickness(λ)and total multilayer thickness(h)on the resulting microstructure and mechanical strength of laser-treated Ti/Ni multilayers was further investigated.Experiments were carried out on fourλ/hcombinations using individual layer thickness of 20 nm and 50 nm,and total multilayer thickness of 500 nm and1μm,respectively.Obvious intermetallic strengthening was observed in the 500 nm thick multilayers,especially with the 20 nm layer thickness,but not in the 1μm thick multilayers.Further,the multilayer surface morphology after laser treatment was observed to be dominated by competition between laser-induced optical interference and thermal melting,with the former leading to ripple or cross-hatched patterns and the latter leading to melted surfaces with pores and cracks.
