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arXiv 2021年

作者： Reed, Albert Blanford, Thomas Brown, Daniel C. Jayasuriya, Suren School of Electrical Computer and Energy Engineering Arizona State University United States The Applied Research Laboratory United States Graduate Program in Acoustics Pennsylvania State University United States

Synthetic aperture sonar (SAS) image resolution is constrained by waveform bandwidth and array geometry. Specifically, the waveform bandwidth determines a point spread function (PSF) that blurs the locations of point scatterers in the scene. In theory, deconvolving the reconstructed SAS image with the scene PSF restores the original distribution of scatterers and yields sharper reconstructions. However, deconvolution is an ill-posed operation that is highly sensitive to noise. In this work, we leverage implicit neural representations (INRs), shown to be strong priors for the natural image space, to deconvolve SAS images. Importantly, our method does not require training data, as we perform our deconvolution through an analysis-by-synthesis optimization in a self-supervised fashion. We validate our method on simulated SAS data created with a point scattering model and real data captured with an in-air circular SAS. This work is an important first step towards applying neural networks for SAS image deconvolution. Copyright © 2021, The Authors. All rights reserved.

关键词： Optical transfer function

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Capnesterones A and B, new steroids isolated from the soft coral Capnella imbricata

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Phytochemistry Letters 2024年 61卷 115-119页

作者： Cheng, Ting-Yu Yang, Chia-Jung Chen, Po-Jen Chen, Yu-Li Peng, Bo-Rong Kung, Te-An Wen, Zhi-Hong Lai, Kuei-Hung Chung, Hsu-Ming Department of Applied Chemistry National Pingtung University Pingtung 900393 Taiwan Clinical Immunology Laboratory Department of Medical Research E-Da Hospital I-Shou University Kaohsiung 824005 Taiwan Research Center for Chinese Herbal Medicine Graduate Institute of Healthy Industry Technology College of Human Ecology Chang Gung University of Science and Technology Taoyuan 33305 Taiwan Graduate Institute of Biomedical Sciences Graduate Institute of Natural Products College of Medicine Chang Gung University Taoyuan 33305 Taiwan Graduate Institute of Pharmacognosy College of Pharmacy Taipei Medical University Taipei 11031 Taiwan Institute of Food Safety Management National Pingtung University of Science and Technology Pingtung 91201 Taiwan Department of Marine Biotechnology and Resources National Sun Yat-sen University Kaohsiung 804201 Taiwan Institute of BioPharmaceutical Sciences National Sun Yat-sen University Kaohsiung 804201 Taiwan PhD Program in Clinical Drug Development of Herbal Medicine College of Pharmacy Taipei Medical University Taipei 11031 Taiwan Traditional Herbal Medicine Research Center Taipei Medical University Hospital Taipei 11031 Taiwan

Two new non-withanolidal steroids with a cross-conjugated dienone structural unit in ring A, capnesterones A (1) and B (2), were isolated from the soft coral Capnella imbricata in the southeast waters of Taiwan. The compounds' structures were elucidated through a comprehensive analysis of spectroscopic data, including IR, ESIMS, ¹H NMR, and ¹³C NMR, and through comparison with previous literature. At a concentration of 10 μM, steroids 1 and 2 exhibited reductions in iNOS levels (60 % and 82 %) compared to LPS-stimulated control cells, along with increased release (134 % and 110 %) against COX-2 protein expressions. © 2024 Phytochemical Society of Europe

关键词： Capnella imbricata COX-2 INOS Steroid

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Three out of one: revising the species delimitation of the tree fern Gymnosphaera salletii (Cyatheaceae), with particular reference to the foliar nectary

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Botanical Journal of the Linnean Society 2024年第1期204卷 63-75页

作者： Li, Shu-Han Zuo, Zheng-Yu Chen, Cheng-Wei Pham, Van The Luu, Hong Truong Dong, Shi-Yong Key Laboratory of Plant Resources Conservation and Sustainable Utilization South China Botanical Garden Chinese Academy of Sciences Guangzhou 510650 China Guangdong Provincial Key Laboratory of Applied Botany South China Botanical Garden Chinese Academy of Sciences Guangzhou 510650 China University of Chinese Academy of Science Beijing 100049 China Germplasm Bank of Wild Species Kunming Institute of Botany Chinese Academy of Sciences Kunming 650201 China Biodiversity Program Taiwan International Graduate Program Academia Sinica National Taiwan Normal University Taipei 115 Taiwan Biodiversity Research Center Academia Sinica Taipei 115 Taiwan Department of Life Science National Taiwan Normal University Taipei 106 Taiwan Laboratory of Ecology and Environmental Management Science and Technology Advanced Institute Van Lang University Ho Chi Minh City Viet Nam Faculty of Applied Technology School of Technology Van Lang University Ho Chi Minh City Viet Nam Southern Institute of Ecology Vietnam Academy of Science and Technology Ho Chi Minh City Viet Nam

In Indochina the species diversity of Cyatheaceae remains insufficiently known. Here we demonstrate the scaly tree fern Gymnosphaera salletii in Vietnam to be an assemblage of three distinct species based on molecular and morphological data, and report for the first time the occurrence of foliar nectaries in Gymnosphaera. The true G. salletii is morphologically unique based on the protuberant glands present on the petiole. Gymnosphaera phankelocii sp. nov. and Gymnosphaera vietnamensis sp. nov. are recognized as new species;G. phankelocii is characterized by its distant two-rowed sori and G. vietnamensis by the sub-tripinnate fronds. Our phylogenetic analyses indicated that G. phankelocii is a relatively isolated species, while G. vietnamensis is a member of the G. salletii clade along with G. austroyunnanensis, G. salletii, and G. saxicola. The two new species and members of the G. salletii clade are all local endemics, and provide good examples to understand the frequent local endemics and their evolution in scaly tree ferns. Eleven species of Gymnosphaera are now known from Indochina;we provide a diagnostic key to these species. © The Author(s) 2023. Published by Oxford University Press on behalf of The Linnean Society of London. All rights reserved.

关键词： Indochina morphology new species phylogeny taxonomy

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An Lc-Ms Based Metabolomic Approach Coupled with Bioassay-Guided Fractionation to Identifying Bioactive Biflavonoids from Selaginella Willdenowii

SSRN

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SSRN 2025年

作者： Thasana, Nopporn Wongsuwan, Sutthida Jumpathong, Watthanachai Chatwichien, Jaruwan Thamnarak, Wanlaya Ngiwsara, Lukana Lirdprapamongkol, Kriengsak Svasti, Jisnuson Ruchirawat, Somsak Program in Chemical Sciences Chulabhorn Graduate Institute 54 Kamphaeng Phet 6 Road Laksi Bangkok10210 Thailand Chulabhorn Royal Academy 906 Kamphaeng Phet 6 Road Laksi Bangkok10210 Thailand OPS Ministry of Higher Education Science Research and Innovation Bangkok10400 Thailand Laboratory of Medicinal Chemistry Chulabhorn Research Institute 54 Kamphaeng Phet 6 Road Laksi Bangkok10210 Thailand Laboratory of Biochemistry Chulabhorn Research Institute Bangkok10210 Thailand Program in Applied Biological Sciences: Environmental Health Chulabhorn Graduate Institute 54 Kamphaeng Phet 6 Road Laksi Bangkok10210 Thailand

The wide-ranging applications of biflavonoids enriched in Selaginella plants, particularly in cuisines and medicines, have attracted interest in the isolation of bioactive biflavonoids. However, identification of bioactive compounds in a complex mixture is a crucial challenge in medicinal plant research. The data set of Selaginella willdenowii fractions having anti-inflammatory activity combined with their LC-MS-based metabolomic profiles was analyzed by the multivariate analysis. The findings suggested that tetrahydrobilobetin and 2′′,3′′-dihydrobilobetin were the potential anti-inflammatory agents. Furthermore, robustaflavone-7′′-methyl ether (9c) demonstrated the strongest cytotoxicity against three cancer cell lines (A549, HepG2, and T47D) with high selectivity for A549 cells. Further mechanistic investigation indicated that 9c induced apoptotic cell death through elevation of ROS level in A549 cells. Notably, this work highlights the potential of applying a metabolomic strategy coupled with bioassay-guided isolation, thereby accelerating research in drug discovery and providing a valuable source of ingredients for the development of value-added food products. © 2025, The Authors. All rights reserved.

关键词： Bioassay

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Real-space and reciprocal-space topology in the Eu(Ga1−xAlx)4 square net system

arXiv

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arXiv 2023年

作者： Moya, Jaime M. Huang, Jianwei Lei, Shiming Allen, Kevin Gao, Yuxiang Sun, Yan Yi, Ming Morosan, E. Applied Physics Graduate Program Rice University HoustonTX77005 United States Department of Physics and Astronomy Rice University HoustonTX77005 United States Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences China

Magnetotransport measurements on the centrosymetric square-net Eu(Ga1−xAlx)4 compounds reveal evidence for both reciprocal- and real-space topology. For compositions 0.50 ≤ x ≤ 0.90, several intermediate field phases are found by magnetization measurements when H || c, where a maximum in the topological Hall effect (THE) is observed, pointing to the existence of topological (real-space topology) or non-coplanar spin textures. For 0.25 ≤ x ≤ 0.39, magnetization measurements reveal an intermediate field state, but no transition is visible in the Hall measurements. For x = 0.15, only one magnetic transition occurs below the Néel temperature TN, and no intermediate field spin reorientations are observed. The Hall effect varies smoothly before the spin-polarized (SP) state. However, in the SP state, Hall measurements reveal a large anomalous Hall effect (AHE) for all compositions, a consequence of reciprocal-space topology. Density functional theory calculations in the paramagnetic state indeed reveal a Dirac point that lies very near the Fermi energy, which is expected to split into Weyl nodes in the SP state, thereby explaining the observed AHE. These results suggest the Eu(Ga1−xAlx)4 family is a rare material platform where real- and reciprocal-space topology exist in a single material platform. © 2023, CC BY.

关键词： Topology

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Non-Hermitian metasurface for asymmetric thermal emission

Non-Hermitian metasurface for asymmetric thermal emission

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Conference on Lasers and Electro-Optics (CLEO)

作者： Ciril S. Prasad Henry O. Everitt Gururaj V. Naik Department of Electrical and Computer Engineering Rice University Houston TX USA Applied Physics Graduate Program Smalley-Curl Institute Rice University Houston TX USA U.S. Army DEVCOM Army Research Laboratory-South Houston TX USA

Non-Hermitian optics provides a unique platform to take advantage of absorption losses in materials and control radiative properties. We demonstrate a non-Hermitian metasurface that exhibit directional suppression of ... 详细信息

ISBN: (纸本)9781957171258

关键词： Fused silica Optical constants Photon counting Remote sensing Thermal emission Thermal imaging

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Real-space and reciprocal-space topology in the Eu(Ga1−xAlx)4 square net system

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Physical Review B 2023年第6期108卷 064436-064436页

作者： Jaime M. Moya Jianwei Huang Shiming Lei Kevin Allen Yuxiang Gao Yan Sun Ming Yi E. Morosan Applied Physics Graduate Program Rice University Houston Texas 77005 USA Department of Physics and Astronomy Rice University Houston Texas 77005 USA Rice Center for Quantum Materials (RCQM) Rice University Houston Texas 77005 USA Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences Shenyang Liaoning 110016 China

Magnetotransport measurements of the centrosymmetric square net Eu(Ga1−xAlx)4 compounds reveal evidence of both reciprocal- and real-space topology. For compositions 0.50≤x≤0.90, several intermediate field phases are found by magnetization measurements when H∥c, where a maximum in the topological Hall effect is observed, pointing to the existence of topological (real-space topology) or noncoplanar spin textures. For 0.25≤x≤0.39, magnetization measurements reveal an intermediate field state, but no transition is visible in the Hall measurements. For x=0.15, only one magnetic transition occurs below the Néel temperature TN, and no intermediate field spin reorientations are observed. The Hall effect varies smoothly before the spin-polarized (SP) state. However, in the SP state, Hall measurements reveal a large anomalous Hall effect (AHE) for all compositions, a consequence of reciprocal-space topology. Density functional theory calculations in the paramagnetic state indeed reveal a Dirac point that lies very near the Fermi energy, which is expected to split into Weyl nodes in the SP state, thereby explaining the observed AHE. These results suggest the Eu(Ga1−xAlx)4 family is a rare material platform where real- and reciprocal-space topology exist in a single material platform.

关键词： Electrical conductivity Electronic structure Hall effect Magnetic order Magnetic texture Magnetotransport Topological order Topological phases of matter Density functional calculations Magnetization measurements Resistivity measurements

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Evanescent wave spectral singularities in non-Hermitian photonics

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Physical Review B 2024年第4期109卷 L041405-L041405页

作者： Huan He Zhaoxian Chen Huanan Li Cheng-Hou Tu Jingjun Xu Andrea Alù MOE Key Laboratory of Weak-Light Nonlinear Photonics School of Physics Nankai University Tianjin 300071 China College of Engineering and Applied Sciences Collaborative Innovation Center of Advanced Microstructures and National Laboratory of Solid State Microstructures Nanjing University Nanjing 210023 China Photonics Initiative Advanced Science Research Center City University of New York New York New York 10031 USA Physics Program Graduate Center City University of New York New York New York 10016 USA

Spectral singularities (SSs) emerge at isolated real frequencies when the scattering coefficients of a system diverge, producing scattering anomalies in non-Hermitian systems. Here, based on parity-time symmetry, we introduce SSs for evanescent waves, and explore their exotic features. We show that evanescent wave SSs can realize highly reconfigurable unidirectional lasers and absorbers, and offer the opportunity to observe extreme scattering anomalies associated with SSs in fully passive platforms, decoupling their extreme scattering responses from energy considerations. More broadly, our study opens avenues for non-Hermitian wave engineering, showcasing a link between non-Hermitian physics and structured waves, with implications in nano-optics for extreme wave-matter interactions and functional devices.

关键词： Evanescent waves Wave scattering Non-Hermitian systems

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Modeling Of Mean Tropospheric Temperature From Convolutional Neural Networks

Modeling Of Mean Tropospheric Temperature From Convolutional...

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IEEE International Symposium on Geoscience and Remote Sensing (IGARSS)

作者： Diego Brum Vinicius Francisco Rofatto Leonardo Scalco Rafaela de Oliveira Pena Luiz Gonzaga Daniel C. Zanotta Luiz Fernando Sapucci Mauricio Roberto Veronez VIZLAB—X-Reality and Geoinformatics Laboratory UNISINOS Sao Leopoldo RS Brazil Graduate Program on Applied Computing UNISINOS Sao Leopoldo RS Brazil Institute of Geography Federal University of Uberlandia Monte Carmelo MG Brazil Graduate Program in Agriculture and Geospatial Information Federal University of Uberlandia Monte Carmelo MG Brazil Brazilian Institute of Space Research (INPE) Cachoeira Paulista SP Brazil

The Mean Tropospheric Temperature (Tm) is important for the sake of the conversion between Zenith Path Delay (ZPD) to Precipitable Water Vapor (PWV) because of the proportionality constant that takes Tm to be calculated. In Brazil, Tm modeling’s been traditionally performed using Multiple Linear Regression Models (MLR). However, recent works suggest the use of Deep Learning methods to model Tm values. In this work, we propose models based on Convolutional Neural Networks (CNN) using radiosonde data from 1961 to 2010. The results show that CNN models can outperform the traditional methods considering different statistic metrics like R, standard deviation, and RMSE.

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Learner Action Patterns in the Problem-Solving Process Related to program Code Composition Based on Tracking System Activities 7

Learner Action Patterns in the Problem-Solving Process Relat...

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7th International Conference on Informatics and Computing, ICIC 2022

作者： Syahidi, Aulia Akhrian Supianto, Ahmad Afif Hirashima, Tsukasa Watanobe, Yutaka Politeknik Negeri Banjarmasin Smart City Information System Applied Undergraduate Program Banjarmasin City Indonesia Research Center for Data and Information Sciences Bandung City Indonesia Graduate School of Advanced Science and Engineering Hiroshima University Kagamiyama Learning Engineering Laboratory Higashihiroshima Japan University of Aizu Division of Information Systems Department of Computer Science and Engineering Fukushima AizuWakamatsu Japan

ISBN: (纸本)9798350345711

Learning activities are an indicator of the learner's desire to learn during the learning process. The pattern of learner action is related to learning activities. In this case, in extracting the learning process, it is necessary to collect a lot of data through analysis of the learning process. The purpose of this study is to recommend and report the performance of an activity tracking system equipped with visual artifacts as an educational data mining approach to analyze action patterns when learners complete the arrangement of program code lines in each programming problem. In this study, data were taken from activity recordings when learners used interactive learning media for a basic programming subject called TOLSYASUPI-EduMed which had problem-solving learning models embedded in their interactions. Learning Analytics is used as a method of this research and data relationships from learner actions during the learning process using the 'if-then' rule. Log data is used for recording and detecting activities carried out by learners. We confirm that the results of the study are based on the findings of the data relationship that if the lines of program code are too long (more than five lines) then almost all learners experience a bottleneck condition. The completion time of each question and the number of iterations in completing the program code lines for each question have also been recorded and have a pattern of connection between the data. The information that has been obtained is then forwarded to teachers or stakeholders as key information to make appropriate feedback to learners based on the results as a means of analyzing and evaluating the programming learning process. © 2022 IEEE.

关键词： Data mining

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