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High-resolution recognition of FOAM modes via an improved EfficientNet V2 based convolutional neural network

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Frontiers of physics 2024年第3期19卷 175-183页

作者： Youzhi shi Zuhai Ma Hongyu Chen Yougang ke yu Chen Xinxing Zhou International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology Institute of Microscale OptoelectronicsShenzhen UniversityShenzhen 518060China key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education Synergetic Innovation Center for Quantum Effects and ApplicationsSchool of Physics and ElectronicsHunan Normal UniversityChangsha 410081China key Laboratory of Hunan Province on Information Photonics and Freespace Optical Communications School of Information Science and EngineeringHunan Institute of Science and TechnologyYueyang 414006China

Vortex beam with fractional orbital angular momentum (FOAM) is the excellent candidate for improving the capacity of free-space optical (FSO) communication system due to its infinite modes. Therefore, the recognition of FOAM modes with higher resolution is always of great concern. In this work, through an improved EfficientNetV2 based convolutional neural network (CNN), we experimentally achieve the implementation of the recognition of FOAM modes with a resolution as high as 0.001. To the best of our knowledge, it is the first time this high resolution has been achieved. Under the strong atmospheric turbulence (AT) (C_(n)^(2)=10^(-15)m^(-2/3)), the recognition accuracy of FOAM modes at 0.1 and 0.01 resolution with our model is up to 99.12% and 92.24% for a long transmission distance of 2000 m. Even for the resolution at 0.001, the recognition accuracy can still remain at 78.77%. This work provides an effective method for the recognition of FOAM modes, which may largely improve the channel capacity of the free-space optical communication.

关键词： OAM free-space optical communication deep learning convolutional neural network

Synergistically constructed lamination-like network of redox-active polyimide and MXene via π-π interactions for aqueous NH_(4)^(+) storage

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Chinese Journal of Chemical Engineering 2024年第7期71卷 217-224页

作者： Jing He Hongye Xuan Jing Jin ke yu Changyao Liyang Lintong Hu Minjie shi Chao Yan School of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China Jiangsu New Yangzi shipbuilding Co. LtdJingjiang 214532China

As a nonmetallic charge carrier,ammonium ion(NH_(4)^(+))has garnered significant attention in the construction of aqueous batteries due to its advantages of low molar mass,small hydration size and rapid diffusion in aqueous *** are a kind of potential electro-active materials for aqueous NH_(4)^(+)***,traditional polymer electrodes are typically created by covering the bulky collectors with excessive additives,which could lead to low volume capacity and unsatisfactory ***,a nanoparticle-like polyimide(PI)was synthesized and then combined with MXene nanosheets to synergistically construct an additive-free and self-standing PI@MXene composite ***,the redox-active PI nanoparticles are enclosed between conductive MXene flakes to create a 3D lamination-like network that promotes electron transmission,while theπ-πinteractions existing between PI and MXene contribute to the enhanced structural integrity and stability within the composite *** such,it delivers superior aqueous NH_(4)^(+)storage behaviors in terms of a notable specific capacity of 110.7 mA·h·cm^(–3) and a long lifespan with only 0.0064%drop each ***,in-situ Raman and UV–Vis examinations provide evidence of reversible and stable redox mechanism of the PI@MXene composite electrode during NH_(4)^(+)uptake/removal,highlighting its significance in the area of electrochemical energy storage.

关键词： Synergetic coupling Composite materials Polyimide Energy storage Aqueous ammonium ion batteries

The Enhanced Period Map and Equivariant Deformation Quantizations of Nilpotent Orbits

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Acta Mathematica Sinica,English Series 2024年第3期40卷 885-934页

作者： shi Lin yu Department of Mathematics School of Mathematical SciencesXiamen UniversityXiamen 361005P.R.China

In a previous paper,the author and his collaborator studied the problem of lifting Hamil-tonian group actions on symplectic varieties and Lagrangian subvarieties to their graded deformation quantizations and apply the general results to coadjoint orbit method for semisimple Lie *** even quantizations were considered *** this paper,these results are generalized to the case of general quantizations with arbitrary *** key step is to introduce an enhanced version of the(truncated)period map defined by Bezrukavnikov and Kaledin for quantizations of any smooth sym-plectic variety X,with values in the space of Picard Lie algebroid over *** an application,we study quantizations of nilpotent orbits of real semisimple groups satisfying certain codimension condition.

关键词： Coadjoint orbit method deformation quantization Harish-Chandra modules semisimple Liegroups

Bayesian partial pooling to reduce uncertainty in overcoring rock stress estimation

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1192-1201页

作者： yu Feng ke Gao Suzanne Lacasse Norwegian Geotechnical Institute OsloNorway Department of Earth and Space Sciences Southern University of Science and TechnologyShenzhenChina

The state of in situ stress is a crucial parameter in subsurface engineering,especially for critical projects like nuclear waste *** one of the two ISRM suggested methods,the overcoring(OC)method is widely used to estimate the full stress tensors in rocks by independent regression analysis of the data from each OC ***,such customary independent analysis of individual OC tests,known as no pooling,is liable to yield unreliable test-specific stress estimates due to various uncertainty sources involved in the OC *** address this problem,a practical and no-cost solution is considered by incorporating into OC data analysis additional information implied within adjacent OC tests,which are usually available in OC measurement ***,this paper presents a Bayesian partial pooling(hierarchical)model for combined analysis of adjacent OC *** performed five case studies using OC test data made at a nuclear waste repository research site of *** results demonstrate that partial pooling of adjacent OC tests indeed allows borrowing of information across adjacent tests,and yields improved stress tensor estimates with reduced uncertainties simultaneously for all individual tests than they are independently analysed as no pooling,particularly for those unreliable no pooling stress estimates.A further model comparison shows that the partial pooling model also gives better predictive performance,and thus confirms that the information borrowed across adjacent OC tests is relevant and effective.

关键词： Overcoring stress measurement Uncertainty reduction Partial pooling Bayesian hierarchical model Nuclear waste repository

Photoinduced superlubricity on TiO_(2) surfaces

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Friction 2024年第3期12卷 428-438页

作者： ke HAN Liran MA yu TIAN Jianbin LUO State key Laboratory of Tribology in Advanced Equipment Tsinghua UniversityBeijing 100084China Received:16 September 2022/Revised:28 October 2022/Accepted:27 December 2022The author(s)2022.

Superlubricity control is of great interest in both industry and scientific research,and several methods have been proposed to achieve this *** this work,ultraviolet(UV)light was introduced into titanium dioxide(TiO_(2))and silicon nitride(Si_(3)N_(4))tribosystems to accomplish photoinduced *** friction coefficients(COFs)between Si_(3)N_(4) balls and TiO_(2) plates in the mixtures of sulfuric acid(H^(2)SO_(4))solution and glycerol solution were obviously reduced,and the system entered the superlubricity region(COFkey to the photoinduced superlubricity in this *** findings showed one method for achieving superlubricity by introducing a light field that could be further applied to special working conditions.

关键词： light control friction superlubricity glycerol titanium dioxide(TiO_(2))

Design and Gait Planning of a Worm-inspired Metameric Robot for Pipe Crawling

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Journal of Bionic Engineering 2024年第3期21卷 1265-1277页

作者： yu Liu Qingbiao shi Zhen Chen Pen-Tung Sah Institute of Micro-Nano Science and Technology Xiamen UniversityXiamen361102China

The earthworm has been attracted much attention in the research and development of biomimetic robots due to their unique locomotion mechanism,compact structure,and small motion *** paper presents a new design and prototype of a worm-inspired metameric robot with a movement pattern similar to that of *** robot consists of multiple telescopic modules connected in series through joint *** telescopic module mimics the contraction and elongation motion modes of the earthworm segments.A kinematic and dynamic analysis is conducted on the telescopic module,and an input torque calculation method is provided to ensure sufficient friction between the robot and the pipe *** gait modes of the prototype robot for straight and turning locomotion are introduced,and these modes are extended to robots constructed by different numbers of telescopic *** addition,a method is proposed to increase the friction between the robot and the pipe wall in the aforementioned gait modes without changing the robot structure,thereby improving the robot’s motion ability in *** theoretical model of gait modes has also been validated through gait *** findings of this paper would provide a useful basis for the design,modeling,and control of future worm inspired robots.

关键词： Bio-inspired robot Spatial linkage mechanism Kinematics model Peristaltic locomotion

Recent progress in all-inorganic tin-based perovskite solar cells:a review

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Science China Chemistry 2024年第4期67卷 1117-1136页

作者： Minghao Wang yu shi School of Electronics and Information Engineering Wuxi UniversityWuxi 214105China Institute of Advanced Materials Nanjing Tech UniversityNanjing 211816China

Recently,power conversion efficiency(PCE)of organic-inorganic hybrid perovskite solar cells(PSCs)has been improved to26.1%.However,the toxicity issue of lead still hinders the large-scale commercial production and application of lead(Pb)-based halide ***,environmentally friendly tin(Sn)-based perovskites have recently shown excellent *** them,the all-inorganic Sn-based perovskites,including CsSnX_(3) and Cs_(2)SnX_(6),have better stability,more suitable bandgap,and higher charge mobility,which have attracted more attention from researchers than organic-inorganic Sn-based hybrid ***,we review recent research progress on all-inorganic Sn-based perovskite materials and corresponding solar cell ***,we also summarize the current challenges and future research directions for this type of PSCs.

关键词： solar cells perovskite all-inorganic CsSnX_(3) Cs_(2)SnX_(6)

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Is Yang-Mills theory unitary in fractional spacetime dimensions?

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Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 59-64页

作者： Qingjun Jin ke Ren Gang Yang Rui yu Graduate School of China Academy of Engineering Physics Beijing 100193China School of Physics and Astronomy Sun Yat-Sen UniversityZhuhai 519082China CAS key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China International Centre for Theoretical Physics Asia-Pacific Hangzhou 310024China School of Physical Science and Technology Inner Mongolia UniversityHohhot 010021China Beijing Computational Science Research Center Beijing 100193China

We present concrete evidence that Yang-Mills theory exhibits non-unitarity in non-integer spacetime *** violation of unitarity stems from evanescent operators that,while vanishing in four dimensions,are non-zero in general d *** demonstrate that these evanescent operators lead to the emergence of both negative-norm states and complex anomalous dimensions.

关键词： gauge field theories field theories in dimensions other than four renormalization

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103 GHz germanium-on-silicon photodiode enabled by an optimized U-shaped electrode

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Photonics Research 2024年第1期12卷 1-6页

作者： Yang shi Xiang Li Mingjie Zou yu yu Xinliang Zhang Wuhan National Laboratory for Optoelectronics&School of Optical and Electronic Information Huazhong University of Science and TechnologyWuhan 430074China School of Mechanical Engineering and Electronic Information China University of GeosciencesWuhan 430074China Optics Valley Laboratory Wuhan 430074China Xidian University Xi’an 710126China

High-performance germanium photodiodes are crucial components in silicon photonic integrated circuits for large-capacity data ***,the bandwidths of most germanium photodiodes are limited by the intractable resistance–capacitance parasitic ***,we introduce a unique U-shaped electrode to alleviate this issue,reducing the parasitic effect by 36%without compromising any other ***,a large bandwidth of 103 GHz,an optical responsivity of 0.95 A/W at 1550 nm,and a dark current as low as 1.3 nA are achieved,leading to a record high specific *** is the first breakthrough to 100 GHz bandwidth among all vertical germanium photodiodes,to the best of our *** eye diagrams of 120 Gb/s on-off keying and 200 Gb/s four-level pulse amplitude signals are well *** work provides a promising solution for chip-based ultra-fast photodetection.

关键词： Gb/s shaped electrode