Speckle patterns are a fundamental tool in a variety of physical and optical applications. Here, we investigate a method of precisely tuning the intensity statistics of random speckle patterns into a desirable pattern...Speckle patterns are a fundamental tool in a variety of physical and optical applications. Here, we investigate a method of precisely tuning the intensity statistics of random speckle patterns into a desirable pattern that possesses the same spatial correlation length and similar statistics distribution. This tuning mechanism relies on the derivation of the transform function and transmission matrix, which achieves different contrasts while maintaining the same average value or energy level. The statistics properties of the generated speckle patterns are further investigated by analyzing the standard deviation under different fitting parameters. Precisely tuning the intensity statistics of random speckle patterns could be useful for both fundamental research and practical applications, such as microscopy, imaging, and optical manipulation.展开更多
To investigate whether industrial robots have improved the ecological environment,this study integrated the adoption of robot technology and pollution abatement into Melitz's heterogeneous firm model.This showed t...To investigate whether industrial robots have improved the ecological environment,this study integrated the adoption of robot technology and pollution abatement into Melitz's heterogeneous firm model.This showed that using robots in production can lower firms'pollution intensity by increasing their abatement investments,and this reduction effect is greater for higher polluting firms and those subject to weaker local environmental regulations.These theoretical expectations were then confirmed through a series of empirical investigations based on Bartik instrument regressions,with multiple robustness checks as well as heterogeneity and mechanism analyses.This paper adds to the literature on the relationships between automation technologies and green transformation.It shows that in the pursuit of economic growth and environmental protection,it is necessary for policymakers to shift from pollution control to technical support for traditional manufacturing firms.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.61702347)the Natural Science Foundation of Hebei Province,China(Grant No.F2017210161)Education Department of Hebei Province,China(Grant No.QN2017132)
文摘Speckle patterns are a fundamental tool in a variety of physical and optical applications. Here, we investigate a method of precisely tuning the intensity statistics of random speckle patterns into a desirable pattern that possesses the same spatial correlation length and similar statistics distribution. This tuning mechanism relies on the derivation of the transform function and transmission matrix, which achieves different contrasts while maintaining the same average value or energy level. The statistics properties of the generated speckle patterns are further investigated by analyzing the standard deviation under different fitting parameters. Precisely tuning the intensity statistics of random speckle patterns could be useful for both fundamental research and practical applications, such as microscopy, imaging, and optical manipulation.
基金supported financially by the Zhejiang Provincial Philosophy and Social Science Planning Project (No.21NDQN303YB).
文摘To investigate whether industrial robots have improved the ecological environment,this study integrated the adoption of robot technology and pollution abatement into Melitz's heterogeneous firm model.This showed that using robots in production can lower firms'pollution intensity by increasing their abatement investments,and this reduction effect is greater for higher polluting firms and those subject to weaker local environmental regulations.These theoretical expectations were then confirmed through a series of empirical investigations based on Bartik instrument regressions,with multiple robustness checks as well as heterogeneity and mechanism analyses.This paper adds to the literature on the relationships between automation technologies and green transformation.It shows that in the pursuit of economic growth and environmental protection,it is necessary for policymakers to shift from pollution control to technical support for traditional manufacturing firms.
