检索结果-内蒙古大学图书馆

2023 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio science Meeting, AP-S/URSI 2023

作者： Arora, Akshaj Cotrufo, Michele Alù, Andrea City University of New York Photonics Initiative Advanced Science Research Center New YorkNY10031 United States University of New York Physics Program Graduate Center of the City New YorkNY10016 United States

ISBN: (纸本)9781665442282

Analog computing using metasurfaces offers significant potential for processing information at ultrahigh speeds and low power consumption. Among several operations, implementing spatial differentiation and edge detection with metasurfaces is an active area of research for its potential impact in the automotive industry and for image recognition. However, current designs have been suffering from limitations due to trade-offs between bandwidth, spatial resolution and efficiency. In this work, dispersion engineering of a nonlocal metasurface is leveraged to obtain analog edge detection over a moderately large operational bandwidth, without sacrificing numerical aperture and efficiency. We demonstrate the implementation of this concept by using a single-layered silicon metasurface with triangular lattice of holes, which exhibits dual-polarization and azimuthally isotropic response up to large numerical apertures (NAs ∼0.35), and with an operational bandwidth of 5 THz around a central wavelength of about 1500 nm. The proposed design approach can also be extended to other platforms, operational frequencies and materials. © 2023 IEEE.

关键词： Edge detection

来源：评论

学校读者我要写书评

暂无评论

Thermal Metasurfaces: Selective Emission of Custom Wavefronts from a Structured Ultrathin Optical Element

Thermal Metasurfaces: Selective Emission of Custom Wavefront...

引用

CLEO: QELS_Fundamental science, QELS 2022

作者： Overvig, Adam C. Mann, Sander A. Alù, Andrea Photonics Initiative Advanced Science Research Center City University of New York New YorkNY10031 United States Physics Program Graduate Center The City University of New York New YorkNY10016 United States

We demonstrate a metasurface platform based on quasibound states in the continuum capable of generating partially coherent designer wavefronts via thermal emission. © Optica Publishing Group 2022, © 2022 The...

ISBN: (纸本)9781557528209

关键词：

来源：评论

学校读者我要写书评

暂无评论

Observation of the thermal Rashba effect: custom polarization sorting in thermal emission

Observation of the thermal Rashba effect: custom polarizatio...

引用

2023 Conference on Lasers and Electro-Optics, CLEO 2023

作者： Overvig, Adam C. Nolen, J. Ryan Alù, Andrea Photonics Initiative Advanced Science Research Center City University of New York New YorkNY10031 United States Physics Program Graduate Center of the City University of New York New YorkNY10016 United States

We experimentally demonstrate symmetry-driven metasurfaces thermally emitting to custom orthogonal polarization states, generalizing the phenomenon of spin-split dispersion to arbitrary polarizations. © Optica Pu...

ISBN: (纸本)9781957171258

关键词：

来源：评论

学校读者我要写书评

暂无评论

Nanophotonics Beyond Passivity Limitations Using Complex Frequency Excitations

Nanophotonics Beyond Passivity Limitations Using Complex Fre...

引用

2023 Conference on Lasers and Electro-Optics, CLEO 2023

作者： Kim, Seunghwi Alù, Andrea Photonics Initiative Advanced Science Research Center City University of New York New YorkNY10031 United States Physics Program Graduate Center City University of New York New YorkNY10016 United States

Non-monochromatic excitations oscillating at complex frequencies can overcome the limits imposed by passivity. We discuss a few examples in which this approach can be successfully implemented in nanophotonic platforms...

ISBN: (纸本)9781957171258

关键词：

来源：评论

学校读者我要写书评

暂无评论

Dielectric Modulation of Two-Dimensional Dipolar Materials

引用

Physical Review Letters 2019年第9期123卷 096101-096101页

作者： Ziwei Wang Erik Luijten Graduate Program in Applied Physics Northwestern University Evanston Illinois 60208 USA Departments of Materials Science & Engineering Engineering Sciences & Applied Mathematics and Physics & Astronomy Northwestern University Evanston Illinois 60208 USA

Spontaneous pattern formation plays an important role in a wide variety of natural phenomena and materials systems. A key ingredient for the occurrence of modulated phases is the presence of competing interactions, generally of different physical origins. We demonstrate that in dipolar films, a prototypical system for pattern formation, patterns can be induced by dielectric effects alone. A rich phase diagram arises, where striped and circular morphologies emerge with geometric properties that can be controlled through variation of particle shape and substrate permittivity or permeability. These effects are particularly enhanced by metamaterial substrates.

关键词： Classical statistical mechanics Dielectrics Electric polarization Pattern formation 2-dimensional systems Interfaces Monte Carlo methods

来源：评论

学校读者我要写书评

暂无评论

Optimization of geometrical parameters of optical interconnect module based on double side perforated silicon optical platform for high coupling efficiency

Optimization of geometrical parameters of optical interconne...

引用

2012 17th Opto-Electronics and Communications Conference, OECC 2012

作者： Jeong, Bong Kyu Ravindran, Sooraj Kang, Eun Kyu Cha, Sung Hyun Lee, Yong Tak Graduate Program of Photonics and Applied Physics Gwangju Institute of Science and Technology 261 Cheomdan-gwagiro Buk-gu Gwangju 500-712 Korea Republic of Department of Information and Communication Gwangju Institute of Science and Technology 261 Cheomdan-gwagiro Buk-gu Gwangju 500-712 Korea Republic of

ISBN: (纸本)9781467309776

We demonstrated a new structure of optical interconnect module based on double side perforated silicon optical platform. This structure can eliminate the use of micro mirrors, lens, and guide pin, leading to a reduced packaging cost and volume. Simulation results show that the proposed structure can result in high coupling efficiency with relaxed permissible error for assembly. © 2012 IEEE.

关键词： Silicon

来源：评论

学校读者我要写书评

暂无评论

SiC structural characterization by non destructive near-field microscopy techniques

SiC structural characterization by non destructive near-fiel...

引用

2022 International Semiconductor Conference, CAS 2022

作者： Wu, Kuan-Ting Vuillermet, Enora Usureau, Elise El-Helou, Youssef Kazan, Michel Woon, Wei-Yen Lazar, Mihai Bruyant, Aurelien Light Nanomaterials and Nanotechnologies Cnrs Emr 7004 University of Technology of Troyes Troyes10004 France Department of Physics National Central University Taoyuan32001 Taiwan Molecular Science and Technology Program Taiwan International Graduate Program Institute of Atomic and Molecular Science Academia Sinica Taipei10617 Taiwan Department of Physics American University of Beirut P.O. Box 11-0236 Riad El-Solh Beirut1107-2020 Lebanon

ISBN: (数字)9781665452557

ISBN: (纸本)9781665452557

SiC sputtered and e-beam evaporated layers have been deposited on 4H-SiC substrates. Recrystallization has been tried by high temperature annealing with two plateaus at 1400°C and 1700°C. The crystallinity was systematically investigated by non destructive near-field microscopy techniques, particularly adapted to the thin thickness of our layers. Good recrystallization is confirmed only on the e-beam evaporated layers and after the higher annealing plateau by preserving 4H substrate polytype. © 2022 IEEE.

关键词： Silicon carbide

来源：评论

学校读者我要写书评

暂无评论

Laser-driven plasma beat-wave propagation in a density-modulated plasma

引用

Physical Review E 2011年第5期84卷 056403-056403页

作者： Devki Nandan Gupta In Hyuk Nam Hyyong Suk Department of Physics and Astrophysics University of Delhi Delhi 110 007 India Advanced Photonics Research Institute and Graduate Program of Photonics and Applied Physics Gwangju Institute of Science and Technology Gwangju 500 712 Korea

A laser-driven plasma beat wave, propagating through a plasma with a periodic density modulation, can generate two sideband plasma waves. One sideband moves with a smaller phase velocity than the pump plasma wave and the other propagates with a larger phase velocity. The plasma beat wave with a smaller phase velocity can accelerate modest-energy electrons to gain substantial energy and the electrons are further accelerated by the main plasma wave. The large phase velocity plasma wave can accelerate these electrons to higher energies. As a result, the electrons can attain high energies during the acceleration by the plasma waves in the presence of a periodic density modulation. The analytical results are compared with particle-in-cell simulations and are found to be in reasonable agreement.

关键词： PLASMA waves ELECTRONS DENSITY PARTICLES (Nuclear physics) ELECTRON accelerators

来源：评论

学校读者我要写书评

暂无评论

Electronic properties of 3d transition metal dihalide monolayers predicted by DFT methods: Is there a pattern or are the results random?

引用

Journal of the Chinese Chemical Society 2023年第3期70卷 359-371页

作者： Chiu, Cheng-chau Wang, Chung-Yu Huang, Bo-Jie Kuo, Jer-Lai Department of Chemistry National Sun Yat-sen University Kaohsiung Taiwan Center for Theoretical and Computational Physics National Sun Yat-sen University Kaohsiung Taiwan Green Hydrogen Research Center National Sun Yat-sen University Kaohsiung Taiwan Institute of Atomic and Molecular Sciences Academia Sinica Taipei Taiwan Molecular Science and Technology Program Taiwan International Graduate Program Academia Sinica Taipei Taiwan Department of Chemistry National Tsing Hua University Hsinchu Taiwan International Graduate Program of Molecular Science and Technology (NTU-MST) National Taiwan University Taipei Taiwan

We use periodic DFT calculations at LDA and PBE level to investigate 3d transition metal dihalide (TMDH) monolayers in H- and T-phase. By analyzing the phonon dispersion, we have obtained a rough overview which combinations may form stable structures. We have focused on identifying and explaining trends in the predicted electronic properties. Although their geometric structures are simple, the associated electronic and magnetic properties are not as easy to understand. At first glance, it seems that there is no clear trend, as even isovalence-electronic TMDH monolayers formed from the same metal but different halides can feature different magnetic moments. The identification of potential trends is further complicated by the fact that for a significant number of species, LDA results and PBE results predict different ground-state electronic structures. By rigorously analyzing the potential energy surfaces associated with different magnetic moments, we could show that the apparent inconsistencies can be easily understood as a result of the differences in the relative energy between electronic states of different magnetic moments. We further show that the trends in the band gaps can be easily rationalized by an electron counting rule based on simple symmetry arguments. © 2022 Chemical Society Located in Taipei and Wiley-VCH GmbH.

关键词： 2D materials DFT electronic structure monolayer spin transition metal dihalides

来源：评论

学校读者我要写书评

暂无评论

An inverted-pendulum thrust stand for high-power electric thrusters

An inverted-pendulum thrust stand for high-power electric th...

引用

AIAA/ASME/SAE/ASEE 42nd Joint Propulsion Conference

作者： Kodys, A.D. Murray, R. Cassady, L. Choueiri, E.Y. Electric Propulsion and Plasma Dynamics Laboratory Mechanical and Aerospace Engineering Department Princeton University Princeton NJ 08511 United States NASA Graduate Student Research Program Princeton Plasma Science and Technology Program United States EPPDyL United States Applied Physics Group United States AIAA United States

ISBN: (纸本)1563478188

The inverted-pendulum method of thrust measurement for high-power electric thrusters is described analytically and experimentally. Two sources of uncertainty in the thrust measurements are investigated: those due to changes in the sensitivity of the inverted pendulum and those due to tare forces resulting from thermal stresses and electromagnetic forces acting on the flexural elements. An idealized analytical model shows that changes in sensitivity occur due to changes in the mass loading of the inverted pendulum and the temperature of the flexure elements. The sensitivity can be increased only at the expense of more stringent requirements on mass loading and thermal control. The results of the model are validated with measurements made using a carefully calibrated inverted pendulum thrust stand having several advantageous design features including gallium pots for current conduction, an optical two-axis displacement sensor, and careful consideration of flexure shape and cooling requirements. The sensitivity is shown to be constant over a wide range of operating conditions. Measurements show that thermal drifts of the stand are linear on the time scale of the thrust measurements and are less than 0.6% of the expected thrust. The thrust stand operation was demonstrated during experiments with a 30-kW lithium-fed applied-field magnetoplasmadynamic thruster. Under nominal conditions (400 A, 0.1 T, 17.5 mg/s) the thermal and electromagnetic tare forces were measured at less than 9% of the thrust and the total thrust uncertainty at ≤ 10% of the thrust.

关键词： Electric propulsion

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：