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Photonics Research 2024年第2期12卷 356-368页

作者： HUAN YUAN zheqiang zhong BIN ZHANG College of Electronics and Information Engineering Sichuan UniversityChengdu 610064China Big Data Analysis and Fusion Application Technology Engineering Laboratory of Sichuan Province Chengdu 610065China

Janus metasurface holography with asymmetric transmission characteristics provides new degrees of freedom for multiplexing technologies.However,earlier metasurfaces with asymmetrical transmission faced limitations in terms of tunability and multifunctionality.In this study,we propose a metasurface color holographic encryption scheme with dynamic switching and asymmetric transmission at visible frequencies using a low-loss nonvolatile optical phase-change material,Sb_(2)S_(3).Using a modified holographic optimization strategy,we achieved highfidelity asymmetric holographic imaging of a nanostructured metasurface.By controlling the incident direction and wavelength of visible light,as well as the level of crystallization of Sb_(2)S_(3),this reconfigurable metasurface enables the precise manipulation of tunable color holographic image displays.In particular,in the semi-crystalline state of Sb_(2)S_(3),the encoded information can be securely encrypted using a two-channel color-holographic image,whereas only a preset camouflaged image is displayed in the crystalline or amorphous state of Sb_(2)S_(3).The proposed multiencrypted Janus metasurface provides a potential approach for dynamic holographic displays with ultrahigh capacity,holographic encryption,and information storage.

关键词： holographic asymmetric visible

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基于相位板旋转排布的超快束匀滑方案

中国激光 2022年第4期49卷 51-60页

作者：邹冬岩熊皓钟哲强张彬四川大学电子信息学院四川成都610065

提出了一种基于相位板旋转排布的束匀滑方案,通过在激光集束中以旋转方式排布具有旋转非对称性的相位板,为集束中各子光光束提供不同的空间相位调制,进而利用存在一定波长差的子光束在靶面的动态干涉,使得焦斑内部散斑在多方向、多维度... 详细信息

提出了一种基于相位板旋转排布的束匀滑方案,通过在激光集束中以旋转方式排布具有旋转非对称性的相位板,为集束中各子光光束提供不同的空间相位调制,进而利用存在一定波长差的子光束在靶面的动态干涉,使得焦斑内部散斑在多方向、多维度快速扫动,从而达到在皮秒时间尺度内改善焦斑均匀性的目的。以2×2集束为例,通过建立基于相位板旋转排布的束匀滑方案物理模型,分析了相位板参数、排布方式、激光束相位畸变参数以及空间偏差对束匀滑效果的影响。结果表明,在基于相位板旋转排布的束匀滑方案中,仅需同时加工多套参数相同的相位板,即可降低相位板的设计、加工难度。此外,该方案的束匀滑效果受激光束相位畸变、相位板排布方式以及空间偏差的影响较小。

关键词：激光光学惯性约束聚变相位板旋转排布束匀滑加工难度

空间引力波探测系统中超光滑光学元件表面散射特性分析

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光电工程 2023年第11期50卷 86-96页

作者：张耘豪钟哲强张彬四川大学电子信息学院四川成都610065

在引力波探测系统中,超光滑光学元件表面散射特性对高精度引力波测量至关重要。本文针对超光滑光学元件,建立了一种能快速准确地分析和预测其表面散射特性的非傍轴标量散射模型Generalized Beckmann-Kirchhoff(GBK)。在此基础上,研究了... 详细信息

在引力波探测系统中,超光滑光学元件表面散射特性对高精度引力波测量至关重要。本文针对超光滑光学元件,建立了一种能快速准确地分析和预测其表面散射特性的非傍轴标量散射模型Generalized Beckmann-Kirchhoff(GBK)。在此基础上,研究了入射角度、散射方位角对P偏振和S偏振入射光的角分辨散射分布的影响,以及入射角度、散射方位角、自相关长度、斜率、截止频率以及表面粗糙度等因素对不同表面统计分布特征下的角分辨散射分布的影响。研究结果可为引力波探测系统中超光滑光学元件的加工、系统杂散光的产生及抑制等提供参考。

关键词：超光滑光学元件表面散射模型偏振散射特性角分辨散射分布

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基于宽带激光拍频的瞬时束匀滑技术

光学学报 2023年第5期43卷 166-173页

作者：吴世江熊皓张寅瑞钟哲强张彬四川大学电子信息学院四川成都610065

针对高功率激光装置对靶面辐照均匀性的需求,提出了一种基于宽带激光拍频的瞬时束匀滑技术。激光集束采用宽带激光,利用连续相位板对焦斑包络进行控制,并结合共轭螺旋相位板使得集束中各子束在焦平面处拍频产生旋转周期不同、位置各异... 详细信息

针对高功率激光装置对靶面辐照均匀性的需求,提出了一种基于宽带激光拍频的瞬时束匀滑技术。激光集束采用宽带激光,利用连续相位板对焦斑包络进行控制,并结合共轭螺旋相位板使得集束中各子束在焦平面处拍频产生旋转周期不同、位置各异的快速运动散斑。合理选择宽带光参数可使得散斑的旋转周期在皮秒至亚皮秒量级,从而达到瞬时匀滑焦斑的目的。通过建立基于宽带激光拍频的瞬时束匀滑技术物理模型,模拟分析了关键参数包括激光带宽和谱线类型对焦斑束匀滑特性的影响和规律,并与双频单色激光拍频技术作了比较分析。研究结果表明,通过合理选取光源谱线类型或增大激光带宽,所提技术可在降低系统要求的基础上增强对激光等离子体不稳定性的抑制,使焦斑实现瞬时匀滑并获得较好的均匀性。

关键词：激光光学惯性约束聚变束匀滑宽带激光激光等离子体不稳定性

Summer extreme precipitation patterns and synoptic-scale circulation precursors over the Tibetan Plateau

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Science China Earth Sciences 2024年第5期67卷 1625-1638页

作者： Zhiyuan DING Yao HA zhong zhong College of Meteorology and Oceanography National University of Defense TechnologyChangsha 410073China Key Laboratory for Virtual Geographic Environment School of Geography ScienceNanjing Normal UniversityNanjing 210023China Jiangsu Collaborative Innovation Center for Climate Change School of Atmospheric SciencesNanjing UniversityNanjing 210023China

In the context of global warming,the extreme summer precipitation over the Tibetan Plateau(TP)has changed significantly.In this study,the summer(June–August)extreme precipitation on the TP was classified into three spatial types by applying the K-means clustering method to the Third Pole Region long time-series high-resolution(1/30°)precipitation dataset(TPHi Pr,1979–2020).The characteristics of the circulation anomalies and precursors corresponding to the extreme precipitation on the TP in summer during 1979–2020 were investigated.The results showed that the summer extreme precipitation of the TP can be categorized into northwestern(NW),southeastern(SE),and southern Himalayan(HS)types based on extreme precipitation thresholds.The NW and SE types are mainly influenced by anomalous signals in the mid-to-high latitude regions upstream of them,whereas the HS type is controlled by the localized subtropical anomalous circulation.On the 8th day before the onset of the NW type,an anomalous cyclone was observed in the western Atlantic Ocean(60°W,50°N),which triggered the west-to-east quasi-latitudinal propagation of Rossby waves.On the onset day of the NW type,the upper troposphere showed positive-negative-positive geopotential height anomalies along the latitudinal 40°N from the Caspian Sea,the western part of Xinjiang,to the northeastern TP.Moisture entered from the Arabian Sea along the southeastern edge of the anomalous cyclone on the southwestern TP and converged in the northwestern TP.Compared to the NW type,the precursors of the SE type appeared at higher latitudes and were more intense.On the 8th day before the onset of the SE type,an anomalous cyclone occurred near Greenland(60°W,70°N)and excited Rossby waves propagating southeastward.On the onset day of the SE type,the upper troposphere showed negative-positive-negative geopotential height anomalies across Eurasia from the Ural Mountains and the Iranian Plateau to the northern TP in the northwest-southeast direction and entered the southeastern TP from the Bay

关键词： Tibetan Plateau Summer extreme precipitation Atmospheric circulation anomaly Precursor Teleconnection wave train

Analysis of photocatalytic degradation of polyamide microplastics in metal salt solution by high resolution mass spectrometry

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Journal of Environmental Sciences 2024年第5期139卷 473-482页

作者： Yunjin zhong Lebing Zhuo Wangyang Lu National Engineering Lab for Textile Fiber Materials&Processing Technology(Zhejiang) School of Materials Science&EngineeringZhejiang Sci-Tech UniversityHangzhou 310018China

Microplastic pollution has become one of the most concerned focuses in the world.Among many treatment methods,photocatalysis is considered to be one of the most environmentally friendly methods.In this work,the photodegradation behavior of polyamide microplastics is studied by using polyamide 6(PA6)as model microplastics and FeCl_(3) as catalyst.It is hoped that the PA6 fiber can be effectively degraded by utilizing the strong oxidizing active species that can be produced after FeCl_(3) is irradiated in water.The results shows that PA6 fiber can be almost completely degraded after 10 days of irradiation in FeCl_(3) aqueous solution,indicating that it is promising to use this new method to solve the problem of PA6type microplastics.In addition,the chain scission mechanism and degradation process of PA6 are analyzed in detail by ultra-high performance liquid chromatography-tandem mass spectrometry(UPLC-MS),which provides a new insight for the study of polymer degradation mechanism.

关键词： FeCl_(3) Photocatalysis Polyamide 6 Chain scission

Hot versus cold subduction initiation

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National Science Review 2024年第2期11卷 101-102页

作者： zhong-Hai Li Key Laboratory of Computational Geodynamics College of Earth and Planetary SciencesUniversity of Chinese Academy of Sciences

In the framework of plate tectonics, subduction initiation(SI) indicates the birth of a plate convergent boundary, which is a key point of plate tectonics and Wilson's cycle; however, its dynamic process is not well c... 详细信息

关键词： DRIVEN CRUST

Early diagnosis and management of neonatal sepsis:a perspective

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World Journal of Pediatrics 2024年第4期20卷 303-306页

作者： Li‑zhong Du Neonatal Intensive Care Unit Children’s Hospital Zhejiang University School of MedicineNational Clinical Research Center for Child Health3333 Binsheng RoadHangzhou 310052China

Neonatal sepsis is an illness caused by bloodstream bacteria or fungal infections that affect newborn infants under 28 days of age.It stands as a significant contributor to morbidity and mortality in neonatal intensive care units(NICUs).With the improved survival rates of very low-birth-weight or extremely premature infants,a growing number of these vulnerable infants are receiving intensive care and undergoing invasive procedures,making nosocomial infections a persistent challenge in NICUs.The mortality rate associated with neonatal sepsis varies depending on factors such as birth weight,gestational age,and other co-morbidities.It can also lead to a range of long-term health consequences,including neurodevelopmental disabilities like cerebral palsy,visual or hearing impairments,and cognitive problems.Furthermore,neonatal sepsis is linked to various adverse outcomes,including respiratory complications,bronchopulmonary dysplasia,nutritional and growth issues,and immunological dysfunction[1].Due to its atypical clinical presentation and the low rate of specific diagnostic indicators,such as a positive blood culture,accurately diagnosing neonatal sepsis is challenging.Consequently,the appropriateness of antibiotic treatment is often a matter of controversy.

关键词： neonatal mortality diagnosis

Modeling and Simulation of Lithium Vacuum Evaporation Process Using COMSOL Multiphysics

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Journal of Thermal Science 2024年第1期33卷 86-100页

作者： LIAN Xuexin zhong Dawen Beijing Key Laboratory of Passive Nuclear Power Safety and Technology North China Electric Power UniversityBeijing 102206China

Based on the COMSOL Multiphysics simulation software,this study carried out modeling and numerical simulation for the evaporation process of liquid metal lithium in the vacuum free molecular flow state.The motion of lithium atoms in the evaporation process was analyzed through a succession of studies.Based on the available experimental values of the saturated vapor pressure of liquid metal lithium,the relationship between saturated vapor pressure and temperature of liquid lithium in the range of 600 K-900 K was obtained.A two-dimensional symmetric model(3.5 mm×20 mm) was established to simulate the transient evaporation process of liquid lithium at wall temperatures of 750 K,780 K,800 K,810 K,825 K,and 850 K,respectively.The effects of temperature,the evaporation coefficient,back pressure,and length-to-diameter ratio on the evaporation process were studied;the variation trends and reasons of the molecular flux and the pressure during the evaporation process were analyzed.At the same time,the evaporation process under variable wall temperature conditions was simulated.This research made the evaporation process of liquid lithium in vacuum molecular flow clearer,and provided theoretical support for the space reactor and nuclear fusion related fields.

关键词： free molecular flow saturated vapor pressure vacuum evaporation liquid lithium metal

Analysis of gravity wave activity during stratospheric sudden warmings in the northern hemisphere

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Earth and Planetary Physics 2024年第2期8卷 415-422页

作者： XuanYun Zeng Guang zhong School of Physics and Electronic Sciences Changsha University of Science and TechnologyChangsha 410000China Key Laboratory of Geospace Environment Chinese Academy of SciencesUniversity of Science&Technology of ChinaHefei 230026China

Due to the significant changes they bring to high latitude stratospheric temperature and wind,stratospheric sudden warmings(SSWs)can have an impact on the propagation and energy distribution of gravity waves(GWs).The variation characteristics of GWs during SSWs have always been an important issue.Using temperature data from January to March in 2014−2016,provided by the Constellation Observing System for Meteorology,Ionosphere and Climate(COSMIC)mission,we have analyzed global GW activity at 15−40 km in the Northern Hemisphere during SSW events.During the SSWs that we studied,the stratospheric temperature rose in one or two longitudinal regions in the Northern Hemisphere;the areas affected extended to the east of 90°W.During these SSWs,the potential energy density(E_(p)of GWs expanded and covered a larger range of longitude and altitude,exhibiting an eastward and downward extension.The E_(p)usually increased,while partially filtered by the eastward zonal winds.When zonal winds weakened or turned westward,E_(p)began to strengthen.After SSWs,the E_(p)usually decreased.These observations can serve as a reference for analyzing the interaction mechanism between SSWs and GWs in future work.

关键词： stratospheric sudden warming gravity wave wind filter