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Photonic Floquet topological insulators in a fractal lattice

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Light(Science & Applications) 2020年第1期9卷 734-740页

作者： Zhaoju Yang Eran Lustig yaakov Lumer Mordechai Segev Physics Department and Solid State Institute Technion-Israel Institute of TechnologyHaifa 32000Israel

We present Floquet fractal topological insulators:photonic topological insulators in a fractal-dimensional lattice consisting of helical *** helical modulation induces an artificial gauge field and leads to a trivial-totopological phase *** quasi-energy spectrum shows the existence of topological edge states corresponding to real-space Chern number *** study the propagation of light along the outer edges of the fractal lattice and find that wavepackets move along the edges without penetrating into the bulk or backscattering even in the presence of *** a similar vein,we find that the inner edges of the fractal lattice also exhibit robust transport when the fractal is of sufficiently high ***,we find topological edge states that span the circumference of a hybrid half-fractal,half-honeycomb lattice,passing from the edge of the honeycomb lattice to the edge of the fractal structure virtually without scattering,despite the transition from two dimensions to a fractal *** system offers a realizable experimental platform to study topological fractals and provides new directions for exploring topological physics.

关键词： transition fractal topological

An efficient method to measure reliability of underwater acoustic communication links

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Journal of Ocean Engineering and Science 2016年第2期1卷 129-134页

作者： Roee Diamant yaakov Bucris Arie Feuer Department of Marine Technology University of HaifaHaifaIsrael Department of Electrical Engineering TechnionHaifaIsrael

We consider the problem of evaluating the reliability of underwater acoustic communication(UWAC)*** is a requirement for any communication system and is often defined as the probability to achieve a target bit error *** of system reliability is often performed empirically by conducting a large number of ***,for UWAC,where experiments are expensive and time-consuming,not much data is available to perform such a reliability *** on the assumption that the long delay spread is the dominant characteristic of the underwater acoustic channel and for a given channel model,we offer a relaxed practical approach to evaluate the reliability of an UWAC *** a test case,we show reliability results for the multiple input multiple output(MIMO)code division multiple access(CDMA)communication system.

关键词： Underwater acoustic communication(UWAC) Reliability Signal-to-interference-plus-noise ratio(SINR)

Simultaneous Scatterer Shape Estimation and Partial Aperture Far-Field Pattern Denoising

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Communications in Computational Physics 2012年第2期11卷 271-284页

作者： yaakov Olshansky Eli Turkel Applied Mathematics Tel-Aviv UniversityIsrael

We study the inverse problem of recovering the scatterer shape from the far-field pattern(FFP)in the presence of ***,only a discrete partial aperture is usually *** problem is ill-posed and is frequently addressed using ***,we propose to use a direct approach denoising the FFP using a filtering *** effectiveness of the technique is studied on a scatterer with the shape of the ellipse with a *** forward scattering problem is solved using the finite element method(FEM).The numerical FFP is additionally corrupted by Gaussian *** shape parameters are found based on a least-square error *** eu¥is a perturbation of the FFP then we attempt to find G,the scatterer shape,which minimizes k u¥−eu¥k using the conjugate gradient method for the denoised FFP.

关键词： Scattering inverse problem far field pattern

Carotenoid Metabolism in Plants： The Role ol Plastids

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Molecular Plant 2018年第1期11卷 58-74页

作者： Tianhu Sun Hui Yuan Hongbo Cao Mohammad Yazdani yaakov Tadmor Li Li Robert W. Holley Center for Agriculture and Health USDA-ARS Cornell University Ithaca NY 14853 USA plant Breeding and Genetics Section School of Integrative Plant Science Cornell University Ithaca NY 14853 USA College of Horticulture Hebei Agricultural University Baoding Hebei 071001 China Plant Science Institute Israeli Agricultural Research Organization Newe Yaar Research Center P.O. Box 1021 Ramat Yishai 30095 Israel

Carotenoids are indispensable to plants and critical in human diets. Plastids are the organelles for carotenoid biosynthesis and storage in plant cells. They exist in various types, which include proplastids, etioplasts, chloroplasts, amyloplasts, and chromoplasts. These plastids have dramatic differences in their capacity to synthesize and sequester carotenoids. Clearly, plastids play a central role in governing carotenogenic activity, carotenoid stability, and pigment diversity. Understanding of carotenoid metabolism and accumulation in various plastids expands our view on the multifaceted regulation of carotenogenesis and facilitates our efforts toward developing nutrient-enriched food crops. In this review, we provide a comprehensive overview of the impact of various types of plastids on carotenoid biosynthesis and accumulation, and discuss recent advances in our understanding of the regulatory control of carotenogenesis and metabolic engineering of carotenoids in light of plastid types in plants.

关键词： carotenoid plastid regulation metabolism metabolic engineering

Carotenoid Pigment Accumulation in Horticultural Plants

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Horticultural Plant Journal 2020年第6期6卷 343-360页

作者： Anna S.Hermanns Xuesong Zhou Qiang Xu yaakov Tadmor Li Li Plant Breeding and Genetics Section School of Integrative Plant ScienceCornell UniversityIthacaNY 14853USA Robert W.Holley Center for Agriculture and Health USDA-Agricultural Research ServiceCornell UniversityIthacaNY 14853USA State Key Laboratory of Crop Genetics&Germplasm Enhancement Nanjing Agricultural UniversityNanjing 210095China Key Laboratory of Horticultural Plant Biology(Ministry of Education) Huazhong Agricultural UniversityWuhan 430070China Department of Vegetable Research ARONewe Ya’ar Research CenterP.O.Box 1021Ramat Yishay 30095Israel

Carotenoids are a group of widely distributed natural *** give many horticultural plants the bright red,orange,and yellow colors,as well as the aroma and *** enhance the health value and represent an essential quality trait of horticultural *** efforts have been made to correlate specific carotenoid production with pathway gene *** transcription factors that directly regulate transcription of the pathway genes have been *** crops have evolved with complicated and multifaceted regulatory mechanisms to generate the enormous diversity in carotenoid content and ***,the diverse and complex control of carotenoid accumulation is still not well *** this review,we depict carotenoid accumulation pathways and highlight the recent progress in the regulatory control of carotenoid accumulation in horticultural *** of the critical roles of chromoplasts for carotenoid hyperproduction,we evaluate chromoplast ultrastructures and carotenoid sequestrations.A perspective on carotenoid research in horticultural crops is provided.

关键词： Carotenoid Chromoplast Pathway Regulation Horticultural crops

Enhancing the formability of FeSi6.5 steel by the anodic polarization

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International Journal of Minerals,Metallurgy and Materials 2022年第11期29卷 2072-2078页

作者： Dong Zhao Feng Ye Binbin Liu Haoyang Du yaakov B.Unigovski Emmanuel M.Gutman Roni Shneck State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China State Grid Jilin Electric Power Research Institute Jilin 130021China Department of Materials Engineering Ben-Gurion University of the NegevBeer-Sheva 84105Israel

The effect of anodic polarization on the plastic deformation behavior and formability of FeSi6.5 steel at room temperature was experimentally investigated through uniaxial tensile and drawing of wire specimen in sulfuric acid solution with current densities of 0-40 mA/*** formability of the FeSi6.5 steel was significantly improved after the anodic *** plastic elongation of the specimen as an anode in the electrochemical environment was 4.4%-7%,but 2.7%in the *** drawing force under the anodic polarization decreased by 12.5%-26%compared to that in deionized *** softening is mainly attributed to the relief in work hardening caused by surface atomic *** work hardening mechanism of the FeSi6.5 steel wires under anodic polarization condition was analyzed using Hollomon equation and Voce relation combined with the Kocks-Mecking *** data support the view that the surface atom dissolution facilitates dislocation ***6.5 steel wires were obtained using electrochemical cold drawing and presented a smooth surface and good ductility without crack after five-pass drawing with a total cross-section area reduction of 88%.The drawing with the assistance of anodic polarization is a promising technology for processing hard and brittle metal materials.

关键词： FeSi6.5 steel plastic deformation anodic polarization Voce equation

Erdheim chester-A rare disease with unique endoscopic features

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World Journal of Gastroenterology 2014年第25期20卷 8309-8311页

作者： Gil Ben-yaakov Daniela Munteanu Ignacio Sztarkier Alexer Fich Doron Schwartz Institute of Gastroenterology and Hepatology Soroka University Medical Center Faculty of Health Science Ben Gurion University of the NegevBeer sheva 84101Israel Institute of Pathology Soroka University Medical Center Faculty of Health Science Ben Gurion University of the Negev Beer sheva 84101 Israel

Erdheim-Chester disease(ECD) is a rare inflammatory syndrome in which systemic infiltration of non-Langerhans cell histiocytes occurs in different sites. Both the etiology and pathophysiology of ECD are unknown, but CD68 positive CD 1a/S100 negative cells are characteristic. The presentation of ECD differs according to the involved organs. This case report describes a patient with ECD and the gastrointestinal manifestations and unique endoscopic appearance as seen in gastroscopy and colonoscopy with histological proof of histiocyte infiltration of the lamina propria. The clinical and endoscopic findings of this unique case, to our knowledge, were never described before, so were the features of the gastrointestinal involvement in this disease.

关键词： Erdheim chester Histiocytes Lamina propria Colon Stomach

Analysis of Rolling Contact Bearings Test Data by the Bımodal Method

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Advances in Materials Physics and Chemistry 2021年第1期11卷 1-6页

作者： yaakov Meged The Faculty of Mechanical Engineering The Technion Israel Institute of Technology Haifa Israel

Lieblein J. and Zelen A. conducted a study of the fatigue life of deep groove ball bearings. This study was based on data of 4948 bearings as obtained from 5 companies and 213 test groups. Among these data is a detailed test report #3183, lot 73, consisting of 23 failed bearings. This report states that the Weibull slope of this group is 2.23, meaning that this distribution is mono sloped. These test data were plotted by the author on a bilinear scale plane, of endurance life versus bearing number and proved to be distinctly bi sloped. This basic difference prompted a wide study resulting in several new findings and set the grounds for a new analysis method.

关键词： Bimodal Fatigue Mechanism Deep Groove Ball Bearings Mechanical Mode Hydraulic Mode Relative Intensity Cavitation Erosion

Generalized laws of refraction and reflection at interfaces between different photonic artificial gauge fields

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Light(Science & Applications) 2020年第1期9卷 45-55页

作者： Moshe-Ishay Cohen Christina Jörg yaakov Lumer Yonatan Plotnik Erik H.Waller Julian Schulz Georg von Freymann Mordechai Segev Physics Department Technion-Israel Institute of TechnologyHaifa 32000Israel Solid State Institute Technion-Israel Institute of TechnologyHaifa 32000Israel Physics Department and Research Center OPTIMAS TU Kaiserslautern67663 KaiserslauternGermany Department of Physics The Pennsylvania State UniversityState CollegePA 16802USA Fraunhofer Institute for Industrial Mathematics ITWM 67663 KaiserslauternGermany

Artificial gauge fields the control over the dynamics of uncharged particles by engineering the potential landscape such that the particles behave as if effective external fields are acting on *** years have witnessed a growing interest in artificial gauge fields generated either by the geometry or by time-dependent modulation,as they have been enablers of topological phenomena and synthetic dimensions in many physical settings,e.g.,photonics,cold atoms,and acoustic ***,we formulate and experimentally demonstrate the generalized laws of refraction and reflection at an interface between two regions with different artificial gauge *** use the symmetries in the system to obtain the generalized Snell law for such a gauge interface and solve for reflection and *** identify total internal reflection(TIR)and complete transmission and demonstrate the concept in *** addition,we calculate the artificial magnetic flux at the interface of two regions with different artificial gauge fields and present a method to concatenate several gauge *** an example,we propose a scheme to make a gauge imaging system-a device that can reconstruct(image)the shape of an arbitrary wavepacket launched from a certain position to a predesigned location.

关键词： gauge refraction interface