检索结果-内蒙古大学图书馆

arXiv 2023年

作者： Yuan, Shuai S.A. Wu, Jie Xu, Hongjing Wang, Tengjiao Li, Da Chen, Xiaoming Huang, Chongwen Sun, Sheng Zheng, Shilie Zhang, Xianmin Li, Er-Ping Sha, Wei E.I. College of Information Science and Electronic Engineering Zhejiang University Hangzhou310027 China Anhui Province Key Laboratory of Simulation and Design for Electronic Information System Hefei Normal University Hefei230601 China Wireless Network Research Department Huawei Technologies Shanghai201206 China School of Information and Communications Engineering Xi’an Jiaotong University Xi’an710049 China School of Electronic Science and Engineering University of Electronic Science and Technology of China Chengdu611731 China

The performance of holographic multiple-input multiple-output (MIMO) communications, employing two-dimensional (2-D) planar antenna arrays, is typically compromised by finite degrees-of-freedom (DOF) stemming from limited array size. The DOF constraint becomes significant when the element spacing approaches approximately half a wavelength, thereby restricting the overall performance of MIMO systems. To break this inherent limitation, we propose a novel three-dimensional (3-D) antenna array that strategically explores the untapped vertical dimension. We investigate the performance of MIMO systems utilizing 3-D arrays across different multi-path scenarios, encompassing Rayleigh channels with varying angular spreads and the 3rd generation partnership project (3GPP) channels. We subsequently showcase the advantages of these 3-D arrays over their 2-D counterparts with the same aperture sizes. As a proof of concept, a practical dipole-based 3-D array, facilitated by an electromagnetic band-gap (EBG) reflecting surface, is conceived, constructed, and evaluated. The experimental results align closely with full-wave simulations, and channel simulations substantiate that the DOF and capacity constraints of traditional holographic MIMO systems can be surpassed by adopting such a 3-D array configuration. © 2023, CC BY-NC-ND.

关键词： Energy gap

来源：评论

学校读者我要写书评

暂无评论

Extension of Gen-Foam to Departure from Nucleate Boiling Prediction and Validation Against the Oecd/Nrc Psbt Benchmark

SSRN

引用

SSRN 2023年

作者： Niu, Yuhang Alessandro, Scolaro Fiorina, Carlo Qin, Hao Lazare, Gauthier Wu, Yingwei Tian, Wenxi Su, Guanghui H. Department of Nuclear Science and Technology Xi’an Jiaotong University Shaanxi Xi’an710049 China Laboratory for Reactor Physics and System Behaviour École Polytechnique Fédérale de Lausanne – EPFL Lausanne1015 Switzerland Department of Nuclear Engineering Texas A&M University College StationTX77843 United States Department of Fluid Mechanics Energy and Environnement EDF R&D Chatou78400 France

The prediction of departure from nucleate boiling (DNB) has always been a crucial aspect of thermal-hydraulic codes for the analysis of Light Water reactors. In this paper, GeN-Foam, a multi-physics code developed based on OpenFOAM, has been enhanced to incorporate DNB prediction using a CHF look-up table as well as post-CHF flow and heat transfer models. To assess GeN-Foam's accuracy in modeling DNB conditions in typical pressurized water reactors (PWRs), a preliminary validation was conducted utilizing Phase II of the PSBT benchmark, including the steady-state fluid temperature (Test Series 1), steady-state DNB (Test Series 4), and transient DNB (Test Series 11T) benchmarks. This paper presents the closure correlations implemented in GeN-Foam, provides a description of the PSBT benchmarks, and includes a comparison between GeN-Foam's predictions and experimental data, as well as code-to-code verification with other participants. The results demonstrate that GeN-Foam exhibits good performance in simulating two-phase flow boiling conditions. Furthermore, GeN-Foam accurately predicts the DNB power and time of occurrence within a ±10% error range compared to measured values, preliminarily indicating its effectiveness in predicting DNB occurrence and two-phase flow boiling phenomena. © 2023, The Authors. All rights reserved.

关键词： Forecasting

来源：评论

学校读者我要写书评

暂无评论

OFDM Achieves the Lowest Ranging Sidelobe Under Random ISAC Signaling

arXiv

引用

arXiv 2024年

作者： Liu, Fan Zhang, Ying Xiong, Yifeng Li, Shuangyang Yuan, Weijie Gao, Feifei Jin, Shi Caire, Giuseppe The National Mobile Communications Research Laboratory Southeast University Nanjing210096 China The School of System Design and Intelligent Manufacturing Southern University of Science and Technology Shenzhen518055 China The School of Information and Electronic Engineering Beijing University of Posts and Telecommunications Beijing100876 China Technical University of Berlin Berlin10623 Germany The Department of Automation Tsinghua University Beijing100084 China

This paper aims to answer a fundamental question in the area of Integrated Sensing and Communications (ISAC): What is the optimal communication-centric ISAC waveform for ranging? Towards that end, we first established a generic framework to analyze the sensing performance of communication-centric ISAC waveforms built upon orthonormal signaling bases and random data symbols. Then, we evaluated their ranging performance by adopting both the periodic and aperiodic autocorrelation functions (P-ACF and A-ACF), and defined the expectation of the integrated sidelobe level (EISL) as a sensing performance metric. On top of that, we proved that among all communication waveforms with cyclic prefix (CP), the orthogonal frequency division multiplexing (OFDM) modulation is the only globally optimal waveform that achieves the lowest ranging sidelobe for quadrature amplitude modulation (QAM) and phase shift keying (PSK) constellations, in terms of both the EISL and the sidelobe level at each individual lag of the P-ACF. As a step forward, we proved that among all communication waveforms without CP, OFDM is a locally optimal waveform for QAM/PSK in the sense that it achieves a local minimum of the EISL of the A-ACF. Finally, we demonstrated by numerical results that under QAM/PSK constellations, there is no other orthogonal communication-centric waveform that achieves a lower ranging sidelobe level than that of the OFDM, in terms of both P-ACF and A-ACF cases. Copyright © 2024, The Authors. All rights reserved.

关键词： Quadrature amplitude modulation

来源：评论

学校读者我要写书评

暂无评论

Unexpectedly high salt accumulation inside carbon nanotubes soaked in very dilute salt solutions

arXiv

引用

arXiv 2018年

作者： Wang, Xueliang Shi, Guosheng Liang, Shanshan Liu, Jian Li, Deyuan Fang, Gang Liu, Renduo Yan, Long Fang, Haiping Center for Thorium Molten Salt Reactor System Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai201800 China Division of Interfacial Water Key Laboratory of Interfacial Physics and Technology and Shanghai Synchrotron Radiation Facility Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai201800 China University of Chinese Academy of Sciences Beijing100049 China Shanghai Applied Radiation Institute Department of Physics Shanghai University Shanghai200444 China School of Physical Science and Technology ShanghaiTech University Shanghai201210 China

We experimentally demonstrate the formation of salt aggregations with unexpectedly high concentration inside multi-walled carbon nanotubes (CNTs) soaked only in dilute salt solutions and even in solutions containing only traces of salts. This finding suggests the blocking of fluid across CNTs by the salt aggregations when CNTs are soaked in a dilute salt solution with the concentration of seawater or even lower, which may open new avenues for the development of novel CNT-based desalination techniques. The high salt accumulation of CNTs also provides a new CNT-based strategy for the collection/extraction of noble metal salts in solutions containing traces of noble metal salts. Theoretical analyses reveal that this high salt accumulation inside CNTs can be mainly attributed to the strong hydrated cation–π interactions of hydrated cations and π electrons in the aromatic rings of CNTs. Copyright © 2018, The Authors. All rights reserved.

关键词： Hydration

来源：评论

学校读者我要写书评

暂无评论

Integration of Mixture of Experts and Multimodal Generative AI in Internet of Vehicles: A Survey

arXiv

引用

arXiv 2024年

作者： Xu, Minrui Niyato, Dusit Kang, Jiawen Xiong, Zehui Jamalipour, Abbas Fang, Yuguang Kim, Dong In Shen, Xuemin The School of Computer Science and Engineering Nanyang Technological University Singapore639798 Singapore The School of Automation Guangdong University of Technology Key Laboratory of Intelligent Information Processing and System Integration of IoT Ministry of Education Guangzhou510006 China Guangdong-HongKong-Macao Joint Laboratory for Smart Discrete Manufacturing Guangzhou510006 China The Pillar of Information Systems Technology and Design Singapore University of Technology and Design Singapore487372 Singapore The School of Electrical and Information Engineering University of Sydney SydneyNSW2006 Australia Department of Computer Science City University of Hong Kong Kowloon Hong Kong The Department of Electrical and Computer Engineering Sungkyunkwan University Suwon16419 Korea Republic of The Department of Electrical and Computer Engineering University of Waterloo WaterlooONN2L 3G1 Canada

Generative AI (GAI) can enhance the cognitive, reasoning, and planning capabilities of intelligent modules in the Internet of Vehicles (IoV) by synthesizing augmented datasets, completing sensor data, and making sequential decisions. In addition, the mixture of experts (MoE) can enable the distributed and collaborative execution of AI models without performance degradation between connected vehicles. In this survey, we explore the integration of MoE and GAI to enable Artificial General Intelligence in IoV, which can enable the realization of full autonomy for IoV with minimal human supervision and applicability in a wide range of mobility scenarios, including environment monitoring, traffic management, and autonomous driving. In particular, we present the fundamentals of GAI, MoE, and their interplay applications in IoV. Furthermore, we discuss the potential integration of MoE and GAI in IoV, including distributed perception and monitoring, collaborative decision-making and planning, and generative modeling and simulation. Finally, we present several potential research directions for facilitating the integration. © 2024, CC BY.

关键词： Integration

来源：评论

学校读者我要写书评

暂无评论

Detecting bulk carbon ferromagnetism in graphene multi-edge structure

arXiv

引用

arXiv 2023年

作者： Wang, Chao Jian, Nan Yin, Meijie Zhang, Xi Yang, Zhi Mo, Xiuhao Kikkawa, Takashi Daimon, Shunsuke Saitoh, Eiji Li, Qian Yan, Wensheng Hou, Dazhi Yang, Lei Diao, Dongfeng Institute of Nanosurface Science and Engineering Shenzhen University Shenzhen518060 China Electron Microscopy Center of Shenzhen University Shenzhen518060 China National Key Laboratory of Radio Frequency Heterogeneous Integration Shenzhen University Shenzhen518060 China Department of Applied Physics The University of Tokyo Tokyo113-8656 Japan Tokyo152-8550 Japan Institute for AI and Beyond The University of Tokyo Tokyo113-8656 Japan WPI Advanced Institute for Materials Research Tohoku University Sendai980-8577 Japan National Synchrotron Radiation Laboratory School of Nuclear Science and Technology University of Science and Technology of China Anhui Hefei230029 China Synergetic Innovation Center of Quantum Information and Quantum Physics University of Science and Technology of China Hefei230026 China Key Laboratory of Education Ministry for Modern Design and Rotor-Bearing System Xi’an Jiaotong University Xi’an710049 China

The emergence of bulk carbon ferromagnetism is long-expected over years. At nanoscale, carbon ferromagnetism was detected in graphene nanoribbon segments1–3, graphene triangulene dimers4,5, and other graphene-like molecules6–8 by analyzing their magnetic edge states via scanning tunneling microscopy(STM)9, and its origin can be explained by local redistribution of electron wave function3,5,8. Recently, there are experimental efforts on discovering orbital ferromagnetism in twisted bilayer graphene10,11, which is still limited in STM region. In larger scale, carbon ferromagnetism can be created by deliberately producing defects in graphite12–14, and detected by macroscopic technical magnetization. Meanwhile, it becomes crucial to determine that the detected magnetization is originated from carbon rather than from magnetic impurities. One solution to eliminate this uncertainty is X-ray magnetic circular dichroism (XMCD). A contrast of dichroism at π* absorption energy was observed in the scanning x-ray microscope image of proton-irradiated graphite15. Nonetheless, a reproducible, full section of XMCD spectrum across C-1s absorption energy has not appeared yet, which should be decisive for assuring the indisputable existence of bulk carbon ferromagnetism. Besides, the lack of direct observation on the atomic structure of the ferromagnetic carbon leaves the structural origin of its ferromagnetism still in mist. In this work, for detecting bulk carbon ferromagnetism, we managed to grow all-carbon film consisting of vertically aligned graphene multi-edge (VGME), which wove into a three-dimensional hyperfine-porous network. Magnetization (M-H) curves and XMCD spectra co-confirmed bulk carbon ferromagnetism of VGME at room temperature, with the average unit magnetic momentum of ~0.0006 μB/atom. The influence of magnetic impurities on magnetization was excluded by both absorption spectra and inductively coupled plasma mass spectrometry measurements. The spin transfer behavio

关键词： Ferromagnetism

来源：评论

学校读者我要写书评

暂无评论

Recent Improvements in the Dart Model for Atmosphere, Topography, Large Landscape, Chlorophyll Fluorescence, Satellite Image Inversion

Recent Improvements in the Dart Model for Atmosphere, Topogr...

引用

IEEE International Symposium on Geoscience and Remote Sensing (IGARSS)

作者： J.P. Gastellu-Etchegorry Y. Wang O. Regaieg T. Yin Z. Malenovsky Z. Zhen X. Yang Z. Tao L. Landier A. Al Bitar Deschamps N. Lauret J. Guilleux E. Chavanon B. Cao J. Qi A. Kallel Z. Mitraka N. Chrysoulakis B. Cook D. Morton Université de Toulouse CESBIO - UPS CNES CNRS IRD Toulouse France Earth System Science Interdisciplinary Center University of Maryland College Park MD USA School of Technology Environments and Design University of Tasmania Hobart Australia College of Geo-Exploration Science and Technology Jilin University Changchun China Institute of Remote Sensing and Digital Earth Chinese Academy of Sciences Beijing China Key Laboratory of Geographical Information Science East China Normal University Shanghai China CNES Toulouse France Beijing Forestry University Beijing China CRNS ATMS Sfax Tunisia Foundation for Research and Technology Hellas (FORTH) Heraklion Greece NASA Goddard Space Flight Center Greenbelt MD USA

ISBN: (数字)9781728163741

ISBN: (纸本)9781728163758

Physical models simulating the radiative budget (RB) and remote sensing (RS) observation of three-dimensional (3D) landscapes are critical to better understand human and natural components of the Earth system and further develop RS technology. DART is one of the most comprehensive 3D models of Earth-atmosphere optical radiative transfer (RT), from ultraviolet (UV) to thermal infrared (TIR). It simulates the optical signal of proximal, aerial and satellite imaging spectrometers and laser scanners, the 3D RB and solar induced chlorophyll fluorescence (SIF) signal, for any urban or natural landscape and any experimental or instrument configuration. It is freely available for research and teaching activities (https://***). Here, five recent advances are presented. 1) Atmosphere RT. 2) RT in non repetitive topography. 3) Monte Carlo modelling for fast RS image simulation of large landscapes. 4) SIF modelling for vegetation simulated as facets and turbid cells. 5) RS image inversion for mapping the optical properties of urban material and the urban radiative budget.

关键词： Atmospheric modeling Three-dimensional displays Terrestrial atmosphere Earth Satellites Computational modeling Surface topography

来源：评论

学校读者我要写书评

暂无评论

Time-varying Characteristics of mmWave Channel based on the Clustered Sparsity Model

Time-varying Characteristics of mmWave Channel based on the ...

引用

IEEE Conference on Vehicular technology (VTC)

作者： Lijun Yang Haitao Lu Xinchao Ge Zhixin Sun Pan Cao School of Internet of Things Nanjing University of Posts and Telecommunications Nanjing China RAN System Design Dept. ZTE Corporation Shenzhen China Shenzhen Key Laboratory of 5G RAN Security Technology Research and Application Shenzhen China School of Modern Posts Nanjing University of Posts and Telecommunications Nanjing China School of Physics Engineering and Computer Science University of Hertfordshire Hatfield UK

A better understanding of the mmWave channel coherence time will play a significant role in both communication and sensing. Traditional literatures consider that the channel coherence time in mmWave communication will be very short due to high frequency, which makes the channel estimation more difficult. However, we believe that the propagation characteristics of the mmWave channel will affect its coherence time, i.e., channel sparsity may limit its time variability. In this paper, we investigate the time-varying nature of mmWave channel by analyzing its Doppler spread based on the clustered sparsity model. After the derivation of Doppler spectrum DPS and the simulation analysis based on the two-cluster channel, we found that the maximum angle between clusters and the power distribution between clusters are two main factors limiting the Doppler spread. Finally, the realistic mmWave NYUSIM model is used for Doppler spread comparative analysis with Clarke’s model and find that Doppler spread of NYUSIM channel is far less than that estimated based on Clarke’s model. Thus, it is demonstrated that even if the mmWave frequency is high, the clustered sparsity characteristics makes its channel coherence time not as short as thought intuitively, which is meaningful for mmWave vehicular sensing and communication.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Approaching the Fundamental Limit of Orbital-Angular-Momentum Multiplexing Through a Hologram Metasurface

引用

Physical Review Applied 2021年第6期16卷 064042-064042页

作者： Shuai S.A. Yuan Jie Wu Menglin L.N. Chen Zhihao Lan Liang Zhang Sheng Sun Zhixiang Huang Xiaoming Chen Shilie Zheng Li Jun Jiang Xianmin Zhang Wei E.I. Sha College of Information Science and Electronic Engineering Zhejiang University Hangzhou 310027 China Department of Education of Anhui Province Ministry of Education and the Key Laboratory of Electromagnetic Environmental Sensing Anhui University Hefei 230039 China Department of Electrical and Electronic Engineering The University of Hong Kong Hong Kong Department of Electronic and Electrical Engineering University College London Torrington Place London WC1E 7JE United Kingdom Anhui Province Key Laboratory of Simulation and Design for Electronic Information System Hefei Normal University Hefei 230601 China School of Electronic Science and Engineering University of Electronic Science and Technology of China Chengdu 611731 China School of Information and Communications Engineering Xi’an Jiaotong University Xi’an 710049 China

Establishing and approaching the fundamental limit of orbital-angular-momentum (OAM) multiplexing are necessary and increasingly urgent for current multiple-input multiple-output research. In this work, we elaborate the fundamental limit in terms of independent scattering channels (or the degrees of freedom of scattered fields) through angular-spectral analysis, in conjunction with a rigorous Green’s function method. The scattering-channel limit is universal for arbitrary spatial-mode multiplexing, which is launched by a planar electromagnetic device, such as antenna, metasurface, etc., with a predefined physical size. As a proof of concept, we demonstrate both theoretically and experimentally the limit by a phase-only metasurface hologram that transforms orthogonal OAM modes to plane-wave modes scattered at critically separated angular-spectral regions. Particularly, a minimax optimization algorithm is applied to suppress angular-spectrum aliasing, achieving good performances in both full-wave simulation and experimental measurement at microwave frequencies. This work offers a theoretical upper bound and corresponding approach route for engineering designs of OAM multiplexing.

关键词： Angular momentum of light Polarization of light Spatial profiles of optical beams Devices Metamaterials Surfaces Holography Light scattering

来源：评论

学校读者我要写书评

暂无评论

Surface morphology and stiffness of cartilage-like tissue repaired with a scaffold-free tissue engineered construct

引用

Journal of Biomechanical science and Engineering 2011年第1期6卷 40-48页

作者： Nansai, Ryosuke Suzuki, Takuya Shimomura, Kazunori Ando, Wataru Nakamura, Norimasa Fujie, Hiromichi Biomechanics Laboratory Graduate School of Engineering Kogakuin University 2665-1 Nakanomachi Hachioji Tokyo 192-0015 Japan Department of Orthopaedics Osaka University Graduate School of Medicine 1-1 Yamadaoka Suita Osaka 565-0871 Japan Faculty of System Design Tokyo Metropolitan University 6-6 Asahigaoka Hino Tokyo 191-0065 Japan Research Institute for Science and Technology Kogakuin University 2665-1 Nakanomachi Hachioji Tokyo 192-0015 Japan

We have been developing a new tissue engineering technique for cartilage repair using a scaffold-free tissue engineered construct (TEC) bio-synthesized from synovium-derived mesenchymal stem cells (MSCs). A round-shaped chondral defect of 8.5 mm in diameter and 2.0 mm in depth created on the medial condyle of immature (4-month-old) and mature (12-month-old) porcine femur was filled with the TEC. Six months after surgery, a cylindrically shaped specimen of 4 mm in diameter and 4-5 mm in depth was extracted. Stiffness measurements were carried out on the specimen using an AFM after the surface image of the specimen was obtained. The TEC-treated tissues exhibited more irregular surface as compared with normal cartilage, regardless of animal maturity. The stiffness of the superficial layer of the TEC-treated tissue was significantly lower than those of the normal cartilage, indicating 6.8±2.3 mN/m in the immature group and 8.8±2.3 mN/m in the mature group. Histological observation indicated that the defects were repaired with a hyaline cartilage-like tissue with positive Safranine O staining, regardless of animal maturity. However, the superficial layer of the repaired tissues was negatively stained with Safranine O. The present study suggests that the recovery of the superficial layer is delayed in both immature and mature animals although the treatment with TEC enhances the repair of partial chondral defects. © 2011 by JSME.

关键词： Surface morphology

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：