For digital image transmission security and information copyright,a new holographic image self-embedding watermarking encryption scheme is proposed.Firstly,the plaintext is converted to the RGB three-color channel,the...For digital image transmission security and information copyright,a new holographic image self-embedding watermarking encryption scheme is proposed.Firstly,the plaintext is converted to the RGB three-color channel,the corresponding phase hologram is obtained by holographic technology and the watermark is self-embedded in the frequency domain.Secondly,by applying the Hilbert transform principle and genetic center law,a complete set of image encryption algorithms is constructed to realize the encryption of image information.Finally,simulation results and security analysis indicate that the scheme can effectively encrypt and decrypt image information and realize the copyright protection of information.The introduced scheme can provide some support for relevant theoretical research,and has practical significance.展开更多
Hydride precipitation in zirconium cladding materials can damage their integrity and durability.Service temperature and material defects have a significant effect on the dynamic growth of hydrides.In this study,we hav...Hydride precipitation in zirconium cladding materials can damage their integrity and durability.Service temperature and material defects have a significant effect on the dynamic growth of hydrides.In this study,we have developed a phasefield model based on the assumption of elastic behaviour within a specific temperature range(613 K-653 K).This model allows us to study the influence of temperature and interfacial effects on the morphology,stress,and average growth rate of zirconium hydride.The results suggest that changes in temperature and interfacial energy influence the length-to-thickness ratio and average growth rate of the hydride morphology.The ultimate determinant of hydride orientation is the loss of interfacial coherency,primarily induced by interfacial dislocation defects and quantifiable by the mismatch degree q.An escalation in interfacial coherency loss leads to a transition of hydride growth from horizontal to vertical,accompanied by the onset of redirection behaviour.Interestingly,redirection occurs at a critical mismatch level,denoted as qc,and remains unaffected by variations in temperature and interfacial energy.However,this redirection leads to an increase in the maximum stress,which may influence the direction of hydride crack propagation.This research highlights the importance of interfacial coherency and provides valuable insights into the morphology and growth kinetics of hydrides in zirconium alloys.展开更多
We devise a color image encryption scheme via combining hyperchaotic map,cross-plane operation and gene theory.First,the hyperchaotic map used in the encryption scheme is analyzed and studied.On the basis of the dynam...We devise a color image encryption scheme via combining hyperchaotic map,cross-plane operation and gene theory.First,the hyperchaotic map used in the encryption scheme is analyzed and studied.On the basis of the dynamics of hyperchaotic map,a color image encryption scheme is designed.At the end of the encryption process,a DNA mutation operation is used to increase the encoding images’randomness and to improve the encryption algorithm’s security.Finally,simulation experiments,performance analysis,and attack tests are performed to prove the effectiveness and security of the designed algorithm.This work provides the possibility of applying chaos theory and gene theory in image encryption.展开更多
Lattice parameters are a basic quantity in material characterization,and a slight alteration in lattice parameters directly affects the properties of materials.However,there are still considerable controversies as to ...Lattice parameters are a basic quantity in material characterization,and a slight alteration in lattice parameters directly affects the properties of materials.However,there are still considerable controversies as to whether lattice expansion or contraction occurs in metallic nanomaterials with size reduction.Here,the size dependences of the lattice parameter and surface free energy of clean Cu(100)films are investigated via simulations.Lattice parameters of the exposed surfaces contract,whereas lattice expansion occurs along the direction perpendicular to the surfaces with decreasing film thicknesses.This is striking since the metallic bonds usually lack strong directionality,and it is always regarded that the lattice variations in all directions are consistent.The contraction parallel to the surface is more severe than the expansion perpendicular to the surface in films.The lattices change from cubic to tetragonal with decreasing film thickness.Consequently,common contractions and occasional expansions of the lattice parameters of Cu nanoparticles have been observed in previous experiments.Increasing free energy and surface free energy with decreasing thicknesses is the thermodynamic origin of the lattice variations.Our study therefore provides a comprehensive physical basis for the surface effects on the lattice variations.展开更多
需求侧响应(demand response,DR)资源是未来能源电力系统中重要的可调控资源。在能源互联网以及智能电网背景下,通过智能能量管理系统(smart energy management system,SEMS)合理地调控用户侧的需求侧响应资源,是实现供需双侧互动以及...需求侧响应(demand response,DR)资源是未来能源电力系统中重要的可调控资源。在能源互联网以及智能电网背景下,通过智能能量管理系统(smart energy management system,SEMS)合理地调控用户侧的需求侧响应资源,是实现供需双侧互动以及电力系统协同互联的重要手段。首先,基于SEMS系统架构,对用户用电设备进行分类建模,在考虑用户用电满意度的条件下,以用户用电成本以及系统负荷波动最小为目标,构建两阶段的用户需求侧响应资源调控策略模型;其次,通过分布式的需求侧响应资源调控机制对用户用电行为进行优化,最大程度上保护用户的用电信息隐私;最后,进行算例仿真,在实时电价条件下,分析上述需求侧响应调控策略对用户用电行为的影响,结果表明上述两阶段的需求侧资源调控模型能够进一步优化用户的用电行为。展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.62061014)。
文摘For digital image transmission security and information copyright,a new holographic image self-embedding watermarking encryption scheme is proposed.Firstly,the plaintext is converted to the RGB three-color channel,the corresponding phase hologram is obtained by holographic technology and the watermark is self-embedded in the frequency domain.Secondly,by applying the Hilbert transform principle and genetic center law,a complete set of image encryption algorithms is constructed to realize the encryption of image information.Finally,simulation results and security analysis indicate that the scheme can effectively encrypt and decrypt image information and realize the copyright protection of information.The introduced scheme can provide some support for relevant theoretical research,and has practical significance.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.U2230401,U1930401,and 12004048)the National Key Research and Development Program of China (Grant No.2021YFB3501503)+1 种基金the Science Challenge Project (Grant No.TZ2018002)the Foundation of LCP。
文摘Hydride precipitation in zirconium cladding materials can damage their integrity and durability.Service temperature and material defects have a significant effect on the dynamic growth of hydrides.In this study,we have developed a phasefield model based on the assumption of elastic behaviour within a specific temperature range(613 K-653 K).This model allows us to study the influence of temperature and interfacial effects on the morphology,stress,and average growth rate of zirconium hydride.The results suggest that changes in temperature and interfacial energy influence the length-to-thickness ratio and average growth rate of the hydride morphology.The ultimate determinant of hydride orientation is the loss of interfacial coherency,primarily induced by interfacial dislocation defects and quantifiable by the mismatch degree q.An escalation in interfacial coherency loss leads to a transition of hydride growth from horizontal to vertical,accompanied by the onset of redirection behaviour.Interestingly,redirection occurs at a critical mismatch level,denoted as qc,and remains unaffected by variations in temperature and interfacial energy.However,this redirection leads to an increase in the maximum stress,which may influence the direction of hydride crack propagation.This research highlights the importance of interfacial coherency and provides valuable insights into the morphology and growth kinetics of hydrides in zirconium alloys.
基金the National Natural Science Foundation of China(Grant No.62061014)the Provincial Natural Science Foundation of Liaoning(Grant No.2020-MS-274)the Basic Scientific Research Projects of Colleges and Universities of Liaoning Province,China(Grant No.LJKZ0545).
文摘We devise a color image encryption scheme via combining hyperchaotic map,cross-plane operation and gene theory.First,the hyperchaotic map used in the encryption scheme is analyzed and studied.On the basis of the dynamics of hyperchaotic map,a color image encryption scheme is designed.At the end of the encryption process,a DNA mutation operation is used to increase the encoding images’randomness and to improve the encryption algorithm’s security.Finally,simulation experiments,performance analysis,and attack tests are performed to prove the effectiveness and security of the designed algorithm.This work provides the possibility of applying chaos theory and gene theory in image encryption.
基金the fellowship of China Postdoctoral Science Foundation(Grant No.2021T140073)the National Natural Science Foundation of China(Grant No.5210011290)+1 种基金the Science Challenge Project of China(Grant No.TZ2018002)the National Key Research and Development Program of China(Grant No.2016YFB0201204).
文摘Lattice parameters are a basic quantity in material characterization,and a slight alteration in lattice parameters directly affects the properties of materials.However,there are still considerable controversies as to whether lattice expansion or contraction occurs in metallic nanomaterials with size reduction.Here,the size dependences of the lattice parameter and surface free energy of clean Cu(100)films are investigated via simulations.Lattice parameters of the exposed surfaces contract,whereas lattice expansion occurs along the direction perpendicular to the surfaces with decreasing film thicknesses.This is striking since the metallic bonds usually lack strong directionality,and it is always regarded that the lattice variations in all directions are consistent.The contraction parallel to the surface is more severe than the expansion perpendicular to the surface in films.The lattices change from cubic to tetragonal with decreasing film thickness.Consequently,common contractions and occasional expansions of the lattice parameters of Cu nanoparticles have been observed in previous experiments.Increasing free energy and surface free energy with decreasing thicknesses is the thermodynamic origin of the lattice variations.Our study therefore provides a comprehensive physical basis for the surface effects on the lattice variations.
文摘需求侧响应(demand response,DR)资源是未来能源电力系统中重要的可调控资源。在能源互联网以及智能电网背景下,通过智能能量管理系统(smart energy management system,SEMS)合理地调控用户侧的需求侧响应资源,是实现供需双侧互动以及电力系统协同互联的重要手段。首先,基于SEMS系统架构,对用户用电设备进行分类建模,在考虑用户用电满意度的条件下,以用户用电成本以及系统负荷波动最小为目标,构建两阶段的用户需求侧响应资源调控策略模型;其次,通过分布式的需求侧响应资源调控机制对用户用电行为进行优化,最大程度上保护用户的用电信息隐私;最后,进行算例仿真,在实时电价条件下,分析上述需求侧响应调控策略对用户用电行为的影响,结果表明上述两阶段的需求侧资源调控模型能够进一步优化用户的用电行为。
