A new epidemic SIRS model with discrete delay on scale-free network is presented. We give the formula of the basic reproductive number for the model and prove that the disease dies out when the basic reproductive numb...A new epidemic SIRS model with discrete delay on scale-free network is presented. We give the formula of the basic reproductive number for the model and prove that the disease dies out when the basic reproductive number is less than unity, while the disease is uniformly persistent when the basic reproductive number is more than unity. Numerical simulations are given to demonstrate the main results.展开更多
Optical-resolution photoacoustic microscopy(OR-PAM)is capable of observing the distribution of optical absorbers inside bio-tissues with a high spatial resolution of micrometers.Unfortunately,due to the employment of ...Optical-resolution photoacoustic microscopy(OR-PAM)is capable of observing the distribution of optical absorbers inside bio-tissues with a high spatial resolution of micrometers.Unfortunately,due to the employment of a tight optical focus,it suffers from a limited depth of field(DOF),making it challenging to achieve highresolution imaging of targets with arbitrary surfaces.Here,we propose a high spatiotemporal adaptive photoacoustic focusing mechanism through integrating a high-speed optical focuser,a time-of-flight contour deriving algorithm,and the rotary-scanning photoacoustic microscopy.The developed system,named high-speed adaptive photoacoustic microscopy(HA-PAM),features an ultrashort focus-shifting time of 5 ms and an enlarged DOF of up to 5 mm.With the assistance of the proposed mechanism,we can achieve a homogeneous lateral resolution of 6μm over a 10 mm circular imaging domain within 5 s.We demonstrate the advantages of HA-PAM through imaging phantoms with curved surfaces,subcutaneous tumor-bearing mice,resected rabbit kidneys,and pulsating mouse brains.The imaging results suggest that this approach provides a high and consistent spatial resolution for imaging bio-tissues with arbitrary surfaces without sacrificing the imaging speed,and has the potential to extend the fundamental and clinical applications of OR-PAM.展开更多
文摘A new epidemic SIRS model with discrete delay on scale-free network is presented. We give the formula of the basic reproductive number for the model and prove that the disease dies out when the basic reproductive number is less than unity, while the disease is uniformly persistent when the basic reproductive number is more than unity. Numerical simulations are given to demonstrate the main results.
基金National Natural Science Foundation of China(61528401,61775028,62022037,81571722)Guangdong Science and Technology Department(2019ZT08Y191,SZBL2020090501013)+3 种基金Guangdong Provincial Department of Education(2021ZDZX1064)Guangdong Provincial Key Laboratory of Advanced Biomaterials(2022B1212010003)Shenzhen Science and Technology Program(JCYJ20200109141222892,KQTD20190929172743294)Start-up grant from Southern University of Science and Technology。
文摘Optical-resolution photoacoustic microscopy(OR-PAM)is capable of observing the distribution of optical absorbers inside bio-tissues with a high spatial resolution of micrometers.Unfortunately,due to the employment of a tight optical focus,it suffers from a limited depth of field(DOF),making it challenging to achieve highresolution imaging of targets with arbitrary surfaces.Here,we propose a high spatiotemporal adaptive photoacoustic focusing mechanism through integrating a high-speed optical focuser,a time-of-flight contour deriving algorithm,and the rotary-scanning photoacoustic microscopy.The developed system,named high-speed adaptive photoacoustic microscopy(HA-PAM),features an ultrashort focus-shifting time of 5 ms and an enlarged DOF of up to 5 mm.With the assistance of the proposed mechanism,we can achieve a homogeneous lateral resolution of 6μm over a 10 mm circular imaging domain within 5 s.We demonstrate the advantages of HA-PAM through imaging phantoms with curved surfaces,subcutaneous tumor-bearing mice,resected rabbit kidneys,and pulsating mouse brains.The imaging results suggest that this approach provides a high and consistent spatial resolution for imaging bio-tissues with arbitrary surfaces without sacrificing the imaging speed,and has the potential to extend the fundamental and clinical applications of OR-PAM.
