Here we propose a new concept of"molecule aging":with some special treatment,a molecule could be"aged"by losing some unknown tiny particles or pieces from atoms in the molecule,Such"aging"...Here we propose a new concept of"molecule aging":with some special treatment,a molecule could be"aged"by losing some unknown tiny particles or pieces from atoms in the molecule,Such"aging"or loss of unknown tiny particles does not change apparently its molecular structure or chemical composition,but some physicochemical properties could be changed irreversibly.We further confirm such"molecule aging"via a long-term electron attacking to age water(H_(2)O)molecules.The IR spectra show no structural difference between the fresh water and the aged one,while the NMR spectra show that the electron attacking can decrease the size of water clusters.Such facts indicate that the electron attacking indeed can"affect"the structure of water molecule slightly but without damaging to its basic molecule frame.Further exploration reveals that the hydrogen evolution reaction(HER)activity of the aged water molecule is lower than the fresh water on the same Pt/C electrocatalyst.The density functional theory calculations indicate that the shortened O-H bond in H_(2)O indeed can present lower HER activity,so the observed size decrease of water clusters from NMR probably could be attributed to the shortening of O-H bond in water molecules.Such results indicate significantly that the molecule aging can produce materials with new functions for new possible applications.展开更多
大多数基于深度学习技术的视觉设备都配备了图像信号处理(Image Signal Processing, ISP)过程以实现RAW数据到RGB图像的转换,同时集成数据预处理过程以完成高效的图像处理。该文在同时考虑ISP和数据预处理过程影响基础上,搭建了深度学...大多数基于深度学习技术的视觉设备都配备了图像信号处理(Image Signal Processing, ISP)过程以实现RAW数据到RGB图像的转换,同时集成数据预处理过程以完成高效的图像处理。该文在同时考虑ISP和数据预处理过程影响基础上,搭建了深度学习视觉应用实验平台,提出针对ISP过程的图像缩放攻击,即精心制作对抗RAW经过ISP过程得到攻击图像,一旦缩放到特定尺寸就会呈现出完全不同的样貌。由于所提出的攻击是由基于ISP过程的梯度驱动的,因此构建了一个等效模型来学习目标ISP的转换过程,利用等效模型的近似梯度来发动攻击。该攻击平台的构建涵盖了深度学习算法、图像处理及对抗攻击优化等内容,有助于学生深入学习和理解基于深度学习视觉应用的任务处理原理以及深度学习模型的弱点,培养学生针对复杂算法问题的创新与实践能力。展开更多
基金funded by the Key Research and Development Program sponsored by the Ministry of Science and Technology(MOST)(2022YFA1203400)National Natural Science Foundation of China(21925205,22072145,21372155,22005294,and 22102172)。
文摘Here we propose a new concept of"molecule aging":with some special treatment,a molecule could be"aged"by losing some unknown tiny particles or pieces from atoms in the molecule,Such"aging"or loss of unknown tiny particles does not change apparently its molecular structure or chemical composition,but some physicochemical properties could be changed irreversibly.We further confirm such"molecule aging"via a long-term electron attacking to age water(H_(2)O)molecules.The IR spectra show no structural difference between the fresh water and the aged one,while the NMR spectra show that the electron attacking can decrease the size of water clusters.Such facts indicate that the electron attacking indeed can"affect"the structure of water molecule slightly but without damaging to its basic molecule frame.Further exploration reveals that the hydrogen evolution reaction(HER)activity of the aged water molecule is lower than the fresh water on the same Pt/C electrocatalyst.The density functional theory calculations indicate that the shortened O-H bond in H_(2)O indeed can present lower HER activity,so the observed size decrease of water clusters from NMR probably could be attributed to the shortening of O-H bond in water molecules.Such results indicate significantly that the molecule aging can produce materials with new functions for new possible applications.
文摘大多数基于深度学习技术的视觉设备都配备了图像信号处理(Image Signal Processing, ISP)过程以实现RAW数据到RGB图像的转换,同时集成数据预处理过程以完成高效的图像处理。该文在同时考虑ISP和数据预处理过程影响基础上,搭建了深度学习视觉应用实验平台,提出针对ISP过程的图像缩放攻击,即精心制作对抗RAW经过ISP过程得到攻击图像,一旦缩放到特定尺寸就会呈现出完全不同的样貌。由于所提出的攻击是由基于ISP过程的梯度驱动的,因此构建了一个等效模型来学习目标ISP的转换过程,利用等效模型的近似梯度来发动攻击。该攻击平台的构建涵盖了深度学习算法、图像处理及对抗攻击优化等内容,有助于学生深入学习和理解基于深度学习视觉应用的任务处理原理以及深度学习模型的弱点,培养学生针对复杂算法问题的创新与实践能力。
