Currently,laser-induced structural modifications in optical materials have been an active field of research.In this paper,we reported structural modifications in the bulk of sapphire due to picosecond(ps)laser filamen...Currently,laser-induced structural modifications in optical materials have been an active field of research.In this paper,we reported structural modifications in the bulk of sapphire due to picosecond(ps)laser filamentation and analyzed the ionization dynamics of the filamentation.Numerical simulations uncovered that the high-intensity ps laser pulses generate plasma through multi-photon and avalanche ionizations that leads to the creation of two distinct types of structural changes in the material.The experimental bulk modifications consist of a void like structures surrounded by cracks which are followed by a submicrometer filamentary track.By increasing laser energy,the length of the damage and filamentary track appeared to increase.In addition,the transverse diameter of the damage zone increased due to the electron plasma produced by avalanche ionizations,but no increase in the filamentary zone diameter was observed with increasing laser energy.展开更多
Wheat [Triticum aestivum L. (Poaceae)] is the staple diet of people in Pakistan. It is attacked by many types of pests. Therefore the purpose of this study was to assess the impact of climate change on the ecology and...Wheat [Triticum aestivum L. (Poaceae)] is the staple diet of people in Pakistan. It is attacked by many types of pests. Therefore the purpose of this study was to assess the impact of climate change on the ecology and epidemiology of various wheat pests in Punjab, Pakistan. Results indicate that maximum weeds hot spots 242 (5.98%) Phalaris minor, 45 (1.18%) wild oat and 203 (5.01%) broad leaf weeds were noted in 2015. Aphid 31 (0.86%) hot spots were recorded in 2016 while maximum army worm 13 (0.26%) hot spots were noted in 2017. Maximum 70 (1.73%) spots of yellow rust and 85 (2.10%) hot spots of brown rust were observed during 2015 while 84 (4.16%) spots of loose smut were observed during 2017. ANOVA shows that years have no significant difference (P > 0.05) but weeks have significant effect on occurrence of these pest incidences except brown rust. But regression ANOVA was significant (P ≤ 0.05) and regression models equations have been developed on the bases of recorded data. Pest incidence was taken as dependent variable Y and weather factors i.e. minimum temperature as X1, maximum temperature as X2, relative humidity as X3 and rain fall as X4 were taken as independent variables. This study will help in recommendations for moving forward aiming at integration of biology of rust and smut diseases of wheat with changing climate for development of resistant varieties for resilient and durable management of these pathogens.展开更多
The article compares a Tibetan and Mongolian manuscript in the personal savings of Mr.Hai Tsung Sheng,individual collectors in Liaoning province,with six other Mongolian translations of the Sakya Legshad translated in...The article compares a Tibetan and Mongolian manuscript in the personal savings of Mr.Hai Tsung Sheng,individual collectors in Liaoning province,with six other Mongolian translations of the Sakya Legshad translated into Mongolian,argued that the newly discovered Sakya Legshad is an independent Mongolian translation,not a copy pf the past.展开更多
基金National Natural Science Foundation of China(51575013,51275011)National Key R&D Program of China(2018 YFB1107500)
文摘Currently,laser-induced structural modifications in optical materials have been an active field of research.In this paper,we reported structural modifications in the bulk of sapphire due to picosecond(ps)laser filamentation and analyzed the ionization dynamics of the filamentation.Numerical simulations uncovered that the high-intensity ps laser pulses generate plasma through multi-photon and avalanche ionizations that leads to the creation of two distinct types of structural changes in the material.The experimental bulk modifications consist of a void like structures surrounded by cracks which are followed by a submicrometer filamentary track.By increasing laser energy,the length of the damage and filamentary track appeared to increase.In addition,the transverse diameter of the damage zone increased due to the electron plasma produced by avalanche ionizations,but no increase in the filamentary zone diameter was observed with increasing laser energy.
文摘Wheat [Triticum aestivum L. (Poaceae)] is the staple diet of people in Pakistan. It is attacked by many types of pests. Therefore the purpose of this study was to assess the impact of climate change on the ecology and epidemiology of various wheat pests in Punjab, Pakistan. Results indicate that maximum weeds hot spots 242 (5.98%) Phalaris minor, 45 (1.18%) wild oat and 203 (5.01%) broad leaf weeds were noted in 2015. Aphid 31 (0.86%) hot spots were recorded in 2016 while maximum army worm 13 (0.26%) hot spots were noted in 2017. Maximum 70 (1.73%) spots of yellow rust and 85 (2.10%) hot spots of brown rust were observed during 2015 while 84 (4.16%) spots of loose smut were observed during 2017. ANOVA shows that years have no significant difference (P > 0.05) but weeks have significant effect on occurrence of these pest incidences except brown rust. But regression ANOVA was significant (P ≤ 0.05) and regression models equations have been developed on the bases of recorded data. Pest incidence was taken as dependent variable Y and weather factors i.e. minimum temperature as X1, maximum temperature as X2, relative humidity as X3 and rain fall as X4 were taken as independent variables. This study will help in recommendations for moving forward aiming at integration of biology of rust and smut diseases of wheat with changing climate for development of resistant varieties for resilient and durable management of these pathogens.
文摘The article compares a Tibetan and Mongolian manuscript in the personal savings of Mr.Hai Tsung Sheng,individual collectors in Liaoning province,with six other Mongolian translations of the Sakya Legshad translated into Mongolian,argued that the newly discovered Sakya Legshad is an independent Mongolian translation,not a copy pf the past.