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Inversely engineered metasurfaces for independent manipulation of transmitted and reflected light fields

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Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 97-106页

作者： Yongjian liu Yu Luo Fei Zhang Mingbo Pu Hanlin Bao Mingfeng Xu Yinghui Guo Lanting li xiong li Xiaoliang Ma Xiangang Luo National Key Laboratory of Optical Field Manipulation Science and Technology Chinese Academy of SciencesChengdu 610209China State Key Laboratory of Optical Technologies on Nano-Fabrication and Micro-Engineering Institute of Optics and ElectronicsChinese Academy of SciencesChengdu 610209China College of Materials Science and Opto-Electronic Technology University of Chinese Academy of SciencesBeijing 100049China Research Center on Vector Optical Fields Institute of Optics and ElectronicsChinese Academy of SciencesChengdu 610209China Tianfu Xinglong Lake Laboratory Chengdu 610299China

Independent manipulation of transmitted and reflected light fields is a key technology for the realization of multifunctional optical applications,which can be implemented based on multilayered plasmonic or supercell subwavelength structures.However,the former is not suitable for the optical bands,while the latter is insufficient in generating large phase gradients.Here,an adjoint-optimization-based inverse design methodology is proposed,which utilizes the polarization-selective local interference between individual meta-atoms and enables monolayer dielectric metasurfaces to decouple the wavefront of transmitted and reflected optical fields.Moreover,this methodology serves to mitigate the aperiodic electromagnetic crosstalk inherent between adjacent meta-atoms,consequently leading to a significant enhancement in the performance of meta-devices.We analyzed the physical mechanism of adjoint optimization and proposed the concept of phase factors,highlighting their importance in the rapid inverse design of meta-devices—an aspect often overlooked in previous research.To demonstrate the feasibility and robustness of our method,we optimize monolayer metasurfaces with different initial structures.These devices efficiently focus and deflect x-linearly and y-linearly polarized incident light in transmission and reflection spaces,respectively.Overall,this methodology holds immense potential for designing multifunctional,high-performing metasurfaces that meet multiple constraints,opening up broad prospects for applications.

关键词： full-space metasurfaces adjoint optimization inverse design

Geochemistry and Zircon U-Pb and Hf Isotopes of Early Devonian Hardawu Granites in the Eastern Segment of the Ultrahigh-Pressure Metamorphic Belt, Northern Qaidam Basin

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Journal of Earth Science 2024年第3期35卷 866-877页

作者： Hua li Ming Wang Jiqing li Haikui Tong Jiaxiang Dong Minggang Tian Xiaolin Chen Leguang li Ting Xie xiong li Yuying Che Qinghai Geological Survey Xining 810000China Technology Innovation Center for Exploration and Exploitation of Strategic Mineral Resources in Plateau Desert Region Ministry of Natural ResourcesXining 810000China Qinghai Geological Survey Institute Xining 810000China Geological Exploration Institute of Shandong Zhengyuan Jinan 271000China School of Earth Science China University of GeosciencesWuhan 430074China

The Hardawu granites in the eastern segment of the ultrahigh-pressure metamorphic belt,the northern Qaidam Basin,were studied by whole-rock major and trace elements and in-situ zircon U-Pb geochronology and Hf isotopes to discuss the petrogenesis and tectonic evolution.Geochronological results show that the granites have a crystallization age of 401±3 Ma,suggesting that they were formed in the Early Devonian.The granites have SiO2 contents of 75.32 wt.%-76.05 wt.%,total alkali contents of 8.23 wt.%-8.36 wt.%,and K2O/Na2O ratios of 1.62-1.91.They were rich in K2O,poor in TiO2,MnO,MgO,and P2O5,and have A/CNK values of 1.05-1.07,Rittmann indexδvalues of 2.05-2.14,and differentiation index(DI)values of 92.85-94.18.They are high potassium calc-alkaline,weakperaluminum,and highly differentiated I-type granites.The granites also show enrichment of large ion lithophile elements(liLE)such as Rb,Ba,and Th,and depletion of high field strength elements(HFSE)such as Nb,Ta,and Ti.The total REE concentrations range from 169 ppm to 232 ppm,with enrichments of light rare earth elements and negative Eu anomalies(δEu=0.39-0.55).The zirconεHf(t)values range from-0.65 to-2.29,and the two-stage model ages(tDM2)changed within a small range of 1.44 to 1.54 Ga,indicating that the magma of the Hardawu granites was originated from the partial melting of Mesoproterozoic lower crustal materials.Combined with previous studies,we suggest that the Hardawu granites were formed in the extensional tectonic setting after the collision between the Qaidam Block and the central and southern Qilian Block in the Early Devonian.

关键词： granite Early Devonian petrogenesis tectonic implication Qaidam Basin geochemistry

一种用于大视场成像和偏振光谱探测的微型可重构超构光学系统

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Engineering 2024年第4期35卷 67-73页

作者： Fei Zhang Minghao liao Mingbo Pu Yinghui Guo lianwei Chen xiong li Qiong He Tongtong Kang Xiaoliang Ma Yuan Ke Xiangang Luo State Key Laboratory of Optical Technologies on Nano-Fabrication and Micro-Engineering Institute of Optics and ElectronicsChinese Academy of SciencesChengdu 610209China National Key Laboratory of Optical Field Manipulation Science and Technology Chinese Academy of SciencesChengdu 610209China School of Optoelectronics University of Chinese Academy of SciencesBeijing 100049China Research Center on Vector Optical Fields Institute of Optics and ElectronicsChinese Academy of SciencesChengdu 610209China Tianfu Xinglong Lake Laboratory Chengdu 610299China

Wide-angle imaging and spectral detection play vital roles in tasks such as target tracking,object classification,and anti-camouflage.However,limited by their intrinsically different architectures,as determined by frequency dispersion requirements,their simultaneous implementation in a shared-aperture system is difficult.Here,we propose a novel concept to realize reconfigurable dual-mode detection based on electrical-control tunable metasurfaces.As a proof-of-concept demonstration,the simultaneous implementation of wide-angle imaging and polarization-spectral detection in a miniature sharedaperture meta-optical system is realized for the first time via the electrical control of cascaded catenary-like metasurfaces.The proposed system supports the imaging(spectral)resolution of approximately 27.8 line-pairs per millimeter(lp·mm^(-1);~80 nm)for an imaging(spectral)mode from 8 to 14 lm.This system also bears a large field of view of about 70,enabling multi-target recognition in both modes.This work may promote the miniaturization of multifunctional optical systems,including spectrometers and polarization imagers,and illustrates the potential industrial applications of meta-optics in biomedicine,security,space exploration,and more.

关键词： Metasurfaces Reconfigurable Imaging Spectral

On traceable iterated line graph and hamiltonian path index

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Applied Mathematics(A Journal of Chinese Universities) 2024年第2期39卷 239-252页

作者： NIU Zhao-hong xiong li-ming YANG Wei-hua School of Mathematical Sciences Shanxi UniversityTaiyuan 030006China School of Mathematics and Statistics Beijing Key Laboratory on MCAACIBeijing Institute of TechnologyBeijing 100081China Department of Mathematics Taiyuan University of TechnologyTaiyuan 030024China

xiong and liu[21]gave a characterization of the graphs G for which the n-iterated line graph L^(n)(G)is hamiltonian,for n≥2.In this paper,we study the existence of a hamiltonian path in L^(n)(G),and give a characterization of G for which L^(n)(G)has a hamiltonian path.As applications,we use this characterization to give several upper bounds on the hamiltonian path index of a graph.

关键词： iterated line graph traceable hamiltonian index hamiltonian path index

Regulation of AMPK activation by extracellular matrix stiffness in pancreatic cancer

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Genes & Diseases 2024年第3期11卷 338-350页

作者： Xin Xu Yuan Fang Somaira Nowsheen Ye-xiong li Zhenkun Lou Min Deng State Key Laboratory of Molecular Oncology and Department of Radiation Oncology National Cancer Center/National Clinical Research Center for Cancer/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100021China Department of General Surgery Shanghai General HospitalShanghai Jiaotong University School of MedicineShanghai 200080China Department of General Surgery Zhongshan HospitalFudan UniversityShanghai 200032China Department of Dermatology University of California San DiegoSan DiegoCA 92093USA Department of Oncology Mayo ClinicRochesterMN 55905USA

The adenosine monophosphate(AMP)-activated protein kinase(AMPK)sits at a cen-tral node in the regulation of energy metabolism and tumor progression.AMPK is best known to sense high cellular ADP or AMP levels,which indicate the depletion of energy stores.Previous studies have shown that the low expression of phosphorylated AMPK is associated with a poor prognosis of pancreatic cancer.In this study,we report that AMPK is also highly sensitive to extracellular matrix(ECM)stiffness.We found that AMPK is activated in cells when cultured under low ECM stiffness conditions and is functionally required for the metabolic switch induced by ECM stiffness.This regulation of AMPK requires the Hippo kinases but not LKB1/CaMKKp.Hippo kinases directly phosphorylate AMPKa at Thr172 to activate AMPK at low ECM stiffness.Furthermore,we found AMPK activity is inhibited in patients with pancreatic ductal adenocarcinoma(PDAC)with high ECM stiffness and is associated with a poor survival outcome.The activation of Hippo kinases by ROCK inhibitor Y-27632 in combination with the mitochondrial inhibitor metformin synergistically activates AMPK and dramatically inhibits PDAC growth.Together,these findings establish a novel model for AMPK regulation by the mechanical properties of ECMs and provide a rationale for simultaneously targeting the ECM stiffness-Hippo kinases-AMPK signaling and low glucose-LKB1-AMPK signaling pathways as an effective therapeutic strategy against PDAC.

关键词： AMPKactivity Cellularmetabolic switch ECM stiffness Hippokinase signaling Pancreaticductal adenocarcinoma

Lateral photovoltaic effect in the Ni-SiO_(2)-Si structure with bias

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Optoelectronics Letters 2024年第5期20卷 257-264页

作者： liNG Xiang ZHU Pengfei ZHU Kun SONG Pei li xiong School of Mathematics Physics and StatisticsShanghai University of Engineering ScienceShanghai 201600China School of Electrical Engineering Liupanshui Normal UniversityLiupanshui 553004China School of Railway Telecommunication Hunan Technical College of Railway High-speedHengyang 421002China

We designed a clamping device to study lateral photovoltaic effect (LPE) in Ni-SiO_(2)-Si structure with bias due to the appropriate barrier height.The LPE has a prominent sensitivity and linearity with 532 nm wavelength laser.The transient response time is 450μs and the relaxation time is 2 250μs in the Ni-SiO_(2)-Si structure without bias.The LPE sensitivity has a significant improvement with bias.The transient response time is 6μs and the relaxion time is 47μs with-7 V bias,not only improving the LPE sensitivity,but also increasing the response speed with bias.The research shows that the Schottky barrier structure can improve the sensitivity and linearity of LPE with bias effectively,and thus it can be used in position sensitive sensors.

关键词： LPE structure effect

THE ABSENCE OF SINGULAR CONTINUOUS SPECTRUM FOR PERTURBED JACOBI OPERATORS

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Acta Mathematica Scientia 2024年第2期44卷 515-531页

作者：傅钲淇黎雄 Department of Basic Sciences Naval Submarine AcademyQingdao266199China Laboratory of Mathematics and Complex Systems(Ministry of Education) School of Mathematical SciencesBeijing Normal UniversityBeijing100875China

This paper is mainly about the spectral properties of a class of Jacobi operators(H_(c,b)u)(n)=c_(n)u(n+1)+c_(n-1)u(n-1)+b_(n)u(n),.where∣c_(n)−1∣=O(n^(−α))and b_(n)=O(n^(−1)).We will show that,forα≥1,the singula... 详细信息

关键词： Jacobi operator singular continuous spectrum Prüfer variables

Influence of powder oxidation on powder properties and formability in H13 hot-work steels processed by electron beam melting

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Journal of Iron and Steel Research(International) 2024年第4期31卷 924-932页

作者： Wei liu Yan Wang li-xiong Han Ying-kang Wei Hui-ping Tang Shi-feng liu School of Metallurgical Engineering Xi'an University of Architecture and TechnologyXi'an 710055ShaanxiChina School of Engineering Zhejiang University City CollegeHangzhou 310015ZhejiangChina

The oxygen content of metal powder is decisive for the recyclability of powder.The research on the effect of oxygen content on powder properties and material formability has practical significance for economical production with additive manufacturing while preventing the waste of resources.Here,we deliberately oxidized the powder by baking at high temperature to increase the oxygen content in the powder and gave the calculation method of the oxygen content in the powder oxidation film.The majority of oxygen element was found in the oxide particles in the powder and the oxide flm on the powder surface,which did affect the flowability of the powder.It is worth noting that the increase in the oxygen content does not change the phase of H13 steel,but it can promote the molten pool flow and obtain a smoother surface.The increase in the oxygen content in the powder is not the decisive factor for the formability and defects of the printed samples.It is the combined effect of the powder deformation,the increase in the oxygen content,and the impurity pollution after repeated use,which leads to the limitation of repeated utilization of the powder.

关键词： Additive manufacturing Electron beam melting H13 steel powder-Powder oxidation

Scheduling Pattern of Time Triggered Ethernet Based on Reinforcement Learning

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Chinese Journal of Electronics 2023年第5期32卷 1022-1035页

作者： HE Feng xiong li ZHOU Xuan li Haoruo xiong Huagang Shenzhen Institute of Beihang University School of Electronics and Information Engineering Beihang University

Time-triggered Ethernet(TTEthernet or TTE for short) is a deterministic and congestion-free network based on the Ethernet standard. It supports mixcritical real-time applications by providing different message classes. The time-triggered(TT) messages have strict end-to-end delay and accurate jitter requirement, and the rate-constrained(RC) messages have less determinism than TT messages but with bounded end-to-end delay requirement. Traditionally, the scheduling of TT messages makes it free of conflicts for the transmission on physical links, but ignoring RC messages scheduling, so it cannot guarantee the transmission of RC messages with a bounded delay. Therefore, the design of TT schedule becomes the key to TTE network applications within avionics environment. In this paper, we propose an algorithm called RLTS based on reinforcement learning and tree search, to optimize the end-to-end delays of both TT and RC messages. Besides, its computation speed is dozens of times faster than satisfied modularity theory(SMT) with asynchronous method for the calculation of the optimal scheduling table. In the case of a large network with more than1000 TT and 1000 RC messages, the RLTS method can find a scheduling timetable in 10 seconds, and reduce the worst-case delay of RC messages averagely by 20% compared to the genetic algorithm. Meanwhile, our algorithm has a good generalization performance, in another word, it can quickly adjust itself to satisfy the scheduling with the similar performance as before. By using our method, the scheduling pattern of TTEthernet is further discussed.According to the experimental results, the uniformly distributed slots scheduling pattern, namely the porosity scheduling model which is usually recommended for TTE application, is not always suitable for general situations.

关键词： Time-triggered Ethernet Schedule pattern Reinforcement learning Network calculus