The deformation,flicker,and drift of a light field owing to complex media such as a turbulent atmosphere have limited its practical applications.Thus,research on invariants in randomly fluctuated light fields has garn...The deformation,flicker,and drift of a light field owing to complex media such as a turbulent atmosphere have limited its practical applications.Thus,research on invariants in randomly fluctuated light fields has garnered considerable attention in recent years.Coherence is a statistical property of light,while its full and quantitative characterization is challenging.Herein,we successfully realize the orthogonal modal decomposition of partially coherent beams and introduce the application of coherence entropy as a global coherence characteristic of such randomly fluctuated light fields.It is demonstrated that coherence entropy remains consistent during propagation in a unitary system by unraveling complex channels.As representative examples,we study the robustness of coherence entropy for partially coherent beams as they propagate through deformed optical systems and turbulent media.Coherence entropy is anticipated to serve as a key metric for evaluating the propagation of partially coherent beams in complex channels.This study paves the way for a broader application scope of a customized low-coherence light field through nonideal optical systems and complex media.展开更多
The wavefront shaping based technique has been introduced to detect the edges of amplitude objects through complex media,but the extraction of the boundary information of invisible phase objects through complex media ...The wavefront shaping based technique has been introduced to detect the edges of amplitude objects through complex media,but the extraction of the boundary information of invisible phase objects through complex media has not been demonstrated yet.Here,we present a phase contrast imaging technique to overcome the scattering,aiming to achieve the edge detection of the phase object through the complex media.An operator based on the experimentally measured transmission matrix is obtained by numerically adding a spiral phase in the Fourier domain.With the inverse of the filtered transmission matrix,we can directly reconstruct the edge enhanced images for both amplitude object and phase object beyond scattering.Experimentally,both digital and real objects are imaged,and the results verify that isotropic edge detection can be achieved with our technique.Our work could benefit the detection of invisible phase objects through complex media.展开更多
This special issue is dedicated to the emerging field of non-Hermitian photonics of complex media, with emphasis on PT-symmetric optical structures. In particular, the papers highlight the variety of applications bein...This special issue is dedicated to the emerging field of non-Hermitian photonics of complex media, with emphasis on PT-symmetric optical structures. In particular, the papers highlight the variety of applications being considered and the ways in which non-Hermitian optics can improve their performance.展开更多
Submission Open:15 March 2017 Submission Deadline:15 April 2017 The idea of parity-time(PT)symmetry,first introduced in quantum mechanics,was recently realized in the context of photonics in the form of balanced gain-...Submission Open:15 March 2017 Submission Deadline:15 April 2017 The idea of parity-time(PT)symmetry,first introduced in quantum mechanics,was recently realized in the context of photonics in the form of balanced gain-loss structures with special symmetries.In recent years。展开更多
This study used both the “digital divide” and “attribution theory” to analyze the propensity of social media use by disaster-prone communities. The study focused on the variables that may affect how social media i...This study used both the “digital divide” and “attribution theory” to analyze the propensity of social media use by disaster-prone communities. The study focused on the variables that may affect how social media is used for disaster management. Structural equation modeling (SEM) was utilized in the study to analyze the data and test the hypotheses after using a survey questionnaire to collect the data. The study’s findings show that: 1) communities that are vulnerable to disasters are less likely to use social media for disaster management, 2) personal effort and intention to use social media for disaster management are positively correlated, and 3) task complexity and intention to use social media for disaster management are negatively correlated. The study added to the body of knowledge regarding the role social media plays in disaster management.展开更多
二氧化碳(CO_(2))捕集与封存技术有利于减少CO_(2)的排放量,近年来针对CO_(2)地质封存形成了从纳米尺度到油气藏尺度的大量研究成果,大多数研究只针对单一维度多孔介质中流动行为开展研究,且物理实验方法受许多不确定性因素影响,十分耗...二氧化碳(CO_(2))捕集与封存技术有利于减少CO_(2)的排放量,近年来针对CO_(2)地质封存形成了从纳米尺度到油气藏尺度的大量研究成果,大多数研究只针对单一维度多孔介质中流动行为开展研究,且物理实验方法受许多不确定性因素影响,十分耗费时间和成本。为了从微观角度深入理解CO_(2)地质封存过程中的渗流行为,提高CO_(2)地质埋存量,基于追踪两相界面动态变化的VOF(Volume of Fluid)方法,分别建立了2D和3D模型,开展了超临界CO_(2)-水两相流动数值模拟研究,对比了不同润湿性、毛细管数、黏度比条件下的CO_(2)团簇分布特征、CO_(2)饱和度变化规律,揭示了孔隙尺度CO_(2)埋存的内在机理。研究结果表明:①随着岩石对CO_(2)润湿性增加,CO_(2)波及范围扩大,同时CO_(2)团簇的卡断频率减少,CO_(2)埋存量增加;②随着毛细管数的增加,驱替模式由毛细指进转变为稳定驱替,CO_(2)埋存量增加;③随着注入超临界CO_(2)黏度逐渐接近水的黏度,两相流体之间的流动阻力降低,促进了“润滑效应”,CO_(2)相的渗流能力提高,CO_(2)埋存量增加;④润湿性、毛细管数、黏度比在不同维度多孔介质模型中对CO_(2)饱和度的影响程度不同。结论认为,基于VOF方法的CO_(2)-水两相渗流模拟研究在孔隙尺度上揭示了CO_(2)地质封存过程中的渗流机理,对CCUS技术的发展有指导意义,也为更大尺度的CO_(2)地质封存研究提供了理论指导和技术支撑。展开更多
基金supported by the National Key Research and Development Program of China(Grant Nos.2022YFA1404800 and 2019YFA0705000)the National Natural Science Foundation of China(Grant Nos.12174280,12204340,12192254,92250304,and 92050202)+2 种基金the China Postdoctoral Science Foundation(Grant No.2022M722325)the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe Key Lab of Modern Optical Technologies of Jiangsu Province(Grant No.KJS2138)
文摘The deformation,flicker,and drift of a light field owing to complex media such as a turbulent atmosphere have limited its practical applications.Thus,research on invariants in randomly fluctuated light fields has garnered considerable attention in recent years.Coherence is a statistical property of light,while its full and quantitative characterization is challenging.Herein,we successfully realize the orthogonal modal decomposition of partially coherent beams and introduce the application of coherence entropy as a global coherence characteristic of such randomly fluctuated light fields.It is demonstrated that coherence entropy remains consistent during propagation in a unitary system by unraveling complex channels.As representative examples,we study the robustness of coherence entropy for partially coherent beams as they propagate through deformed optical systems and turbulent media.Coherence entropy is anticipated to serve as a key metric for evaluating the propagation of partially coherent beams in complex channels.This study paves the way for a broader application scope of a customized low-coherence light field through nonideal optical systems and complex media.
基金This work was supported by the National Key Research and Development Program of China(No.2019YFA0705000)the National Natural Science Foundation of China(NSFC)(Nos.12004219,120742251,2192254,91750201,and 11974218)+1 种基金the Innovation Group of Jinan(No.2018GXRC010)the Local Science and Technology Development Project of the Central Government(No.YDZX20203700001766).
文摘The wavefront shaping based technique has been introduced to detect the edges of amplitude objects through complex media,but the extraction of the boundary information of invisible phase objects through complex media has not been demonstrated yet.Here,we present a phase contrast imaging technique to overcome the scattering,aiming to achieve the edge detection of the phase object through the complex media.An operator based on the experimentally measured transmission matrix is obtained by numerically adding a spiral phase in the Fourier domain.With the inverse of the filtered transmission matrix,we can directly reconstruct the edge enhanced images for both amplitude object and phase object beyond scattering.Experimentally,both digital and real objects are imaged,and the results verify that isotropic edge detection can be achieved with our technique.Our work could benefit the detection of invisible phase objects through complex media.
文摘This special issue is dedicated to the emerging field of non-Hermitian photonics of complex media, with emphasis on PT-symmetric optical structures. In particular, the papers highlight the variety of applications being considered and the ways in which non-Hermitian optics can improve their performance.
文摘Submission Open:15 March 2017 Submission Deadline:15 April 2017 The idea of parity-time(PT)symmetry,first introduced in quantum mechanics,was recently realized in the context of photonics in the form of balanced gain-loss structures with special symmetries.In recent years。
文摘This study used both the “digital divide” and “attribution theory” to analyze the propensity of social media use by disaster-prone communities. The study focused on the variables that may affect how social media is used for disaster management. Structural equation modeling (SEM) was utilized in the study to analyze the data and test the hypotheses after using a survey questionnaire to collect the data. The study’s findings show that: 1) communities that are vulnerable to disasters are less likely to use social media for disaster management, 2) personal effort and intention to use social media for disaster management are positively correlated, and 3) task complexity and intention to use social media for disaster management are negatively correlated. The study added to the body of knowledge regarding the role social media plays in disaster management.
文摘二氧化碳(CO_(2))捕集与封存技术有利于减少CO_(2)的排放量,近年来针对CO_(2)地质封存形成了从纳米尺度到油气藏尺度的大量研究成果,大多数研究只针对单一维度多孔介质中流动行为开展研究,且物理实验方法受许多不确定性因素影响,十分耗费时间和成本。为了从微观角度深入理解CO_(2)地质封存过程中的渗流行为,提高CO_(2)地质埋存量,基于追踪两相界面动态变化的VOF(Volume of Fluid)方法,分别建立了2D和3D模型,开展了超临界CO_(2)-水两相流动数值模拟研究,对比了不同润湿性、毛细管数、黏度比条件下的CO_(2)团簇分布特征、CO_(2)饱和度变化规律,揭示了孔隙尺度CO_(2)埋存的内在机理。研究结果表明:①随着岩石对CO_(2)润湿性增加,CO_(2)波及范围扩大,同时CO_(2)团簇的卡断频率减少,CO_(2)埋存量增加;②随着毛细管数的增加,驱替模式由毛细指进转变为稳定驱替,CO_(2)埋存量增加;③随着注入超临界CO_(2)黏度逐渐接近水的黏度,两相流体之间的流动阻力降低,促进了“润滑效应”,CO_(2)相的渗流能力提高,CO_(2)埋存量增加;④润湿性、毛细管数、黏度比在不同维度多孔介质模型中对CO_(2)饱和度的影响程度不同。结论认为,基于VOF方法的CO_(2)-水两相渗流模拟研究在孔隙尺度上揭示了CO_(2)地质封存过程中的渗流机理,对CCUS技术的发展有指导意义,也为更大尺度的CO_(2)地质封存研究提供了理论指导和技术支撑。
