High temperature annealing is often used for the stress control of optical materials.However,weight and viscosity at high temperature may destroy the surface morphology,especially for the large-scale,thin and heavy op...High temperature annealing is often used for the stress control of optical materials.However,weight and viscosity at high temperature may destroy the surface morphology,especially for the large-scale,thin and heavy optics used for large laser facilities.It is necessary to understand the thermal behaviour and design proper support systems for large-scale optics at high temperature.In this work,three support systems for fused silica optics are designed and simulated with the finite element method.After the analysis of the thermal behaviours of different support systems,some advantages and disadvantages can be revealed.The results show that the support with the optical surface vertical is optimal because both pollution and deformation of optics could be well controlled during annealing at high temperature.Annealing process of the optics irradiated by CO2 laser is also simulated.It can be concluded that high temperature annealing can effectively reduce the residual stress.However,the effects of annealing on surface morphology of the optics are complex.Annealing creep is closely related to the residual stress and strain distribution.In the region with large residual stress,the creep is too large and probably increases the deformation gradient which may affect the laser beam propagation.展开更多
Banerjee-Ghosh's work shows that the singularity problem can be naturally avoided by the fact that black hole evaporation stops when the remnant mass is greater than the critical mass when including the generalize...Banerjee-Ghosh's work shows that the singularity problem can be naturally avoided by the fact that black hole evaporation stops when the remnant mass is greater than the critical mass when including the generalized uncertainty principle(GUP)effects with first-and second-order corrections.In this paper,we first follow their steps to reexamine Banerjee-Ghosh's work,but we find an interesting result:the remnant mass is always equal to the critical mass at the final stage of black hole evaporation with the inclusion of the GUP effects.Then,we use Hossenfelder's GUP,i.e.,another GUP model with higher-order corrections,to restudy the final evolution behavior of the black hole evaporation,and we confirm the intrinsic self-consistency between the black hole remnant and critical masses once more.In both cases,we also find that the thermodynamic quantities are not singular at the final stage of black hole evaporation.展开更多
基金Project supported by the Joint Fund of the National Natural Science Foundation of China and the China Academy of Engineering Physics (Grant No. 11076008)the Foundation for Young Scholars of University of Electronic Science and Technology of China (Grant No. L08010401JX0806)the Fundamental Research Funds for the Central Universities,China (Grant No. ZYGX2009X007)
文摘High temperature annealing is often used for the stress control of optical materials.However,weight and viscosity at high temperature may destroy the surface morphology,especially for the large-scale,thin and heavy optics used for large laser facilities.It is necessary to understand the thermal behaviour and design proper support systems for large-scale optics at high temperature.In this work,three support systems for fused silica optics are designed and simulated with the finite element method.After the analysis of the thermal behaviours of different support systems,some advantages and disadvantages can be revealed.The results show that the support with the optical surface vertical is optimal because both pollution and deformation of optics could be well controlled during annealing at high temperature.Annealing process of the optics irradiated by CO2 laser is also simulated.It can be concluded that high temperature annealing can effectively reduce the residual stress.However,the effects of annealing on surface morphology of the optics are complex.Annealing creep is closely related to the residual stress and strain distribution.In the region with large residual stress,the creep is too large and probably increases the deformation gradient which may affect the laser beam propagation.
基金Supported by the Program for NCET-12-1060,by the Sichuan Youth Science and Technology Foundation(2011JQ0019),FANEDD(201319)the Innovative Research Team in College of Sichuan Province(13TD0003)+1 种基金Ten Thousand Talent Program of Sichuan Province,Sichuan Natural Science Foundation(16ZB0178)Meritocracy Research Funds of China West Normal University(17YC513,17C050)。
文摘Banerjee-Ghosh's work shows that the singularity problem can be naturally avoided by the fact that black hole evaporation stops when the remnant mass is greater than the critical mass when including the generalized uncertainty principle(GUP)effects with first-and second-order corrections.In this paper,we first follow their steps to reexamine Banerjee-Ghosh's work,but we find an interesting result:the remnant mass is always equal to the critical mass at the final stage of black hole evaporation with the inclusion of the GUP effects.Then,we use Hossenfelder's GUP,i.e.,another GUP model with higher-order corrections,to restudy the final evolution behavior of the black hole evaporation,and we confirm the intrinsic self-consistency between the black hole remnant and critical masses once more.In both cases,we also find that the thermodynamic quantities are not singular at the final stage of black hole evaporation.
