检索结果-内蒙古大学图书馆

Unraveling the complex electronic and topological landscape of triclinic enantiomorphic NbPxAs1−x alloys through first-principles analysis

引用

Physical Review materials 2023年第11期7卷 114202-114202页

作者： Samira Sadat Nourizadeh Aminollah Vaez Daryoosh Vashaee Faculty of Physics University of Isfahan Isfahan *** Iran Department of Electrical and Computer Engineering North Carolina State University Raleigh North Carolina 27606 USA Department of Materials Science and Engineering North Carolina State University Raleigh North Carolina 27606 USA

This paper undertakes a comprehensive examination of the electronic and topological properties of triclinic enantiomorphic NbPxAs1−x alloys (x =0, 0.25, 0.50, 0.75, 1) belonging to the space group P1, through first-principles and Wannier-based tight-binding analyses. Our paper reveals band inversion coupled with a distinctive fourfold band crossing near the Fermi energy, attributed to hybridization among Nb-d orbitals. Intriguingly, NbPxAs1−x alloys exhibit nontrivial topological features even without spin-orbit coupling (SOC), primarily due to band inversion. Upon incorporating SOC, the fourfold band crossings transition into gapped bands, bifurcating into pairs of Weyl points with distinct chiralities. These Weyl points possess linear dispersion, categorizing the alloys as type-I topological Weyl semimetals. Additionally, SOC induces the emergence of Fermi arcs in the (111) surface states of the first Brillouin zone, connecting Weyl points of opposite chiralities. The findings establish NbPxAs1−x alloys as promising candidates for applications in topological materials, while enriching the understanding of topological phases and their correlations with electronic structure.

关键词： Symmetry protected topological states Topological phase transition Topological phases of matter

来源：评论

学校读者我要写书评

暂无评论

Acoustofluidic separation enables early diagnosis of traumatic brain injury based on circulating exosomes

引用

Microsystems & Nanoengineering 2021年第2期7卷 59-69页

作者： Zeyu Wang Haichen Wang Ryan Becker Joseph Rufo Shujie Yang Brian E.Mace Mengxi Wu Jun Zou Daniel T.Laskowitz Tony Jun Huang Department of Mechanical Engineering and Materials Science Duke UniversityDurhamNC27708USA Department of Neurology Duke UniversityDurhamNC27708USA Department of Biomedical Engineering Duke UniversityDurhamNC27708USA Department of Geriatrics Duke UniversityDurhamNC27708USA Department of Electrical&Computer Engineering Texas A&M UniversityCollege StationTX77840USA

Traumatic brain injury(TBI)is a global cause of morbidity and *** management and risk stratification of patients with TBI is made difficult by the relative insensitivity of screening radiographic studies as well as by the absence of a widely available,noninvasive diagnostic *** particular,a blood-based biomarker assay could provide a quick and minimally invasive process to stratify risk and guide early management strategies in patients with mild TBI(mTBI).Analysis of circulating exosomes allows the potential for rapid and specific identification of tissue *** applying acoustofluidic exosome separation—which uses a combination of microfluidics and acoustics to separate bioparticles based on differences in size and acoustic properties—we successfully isolated exosomes from plasma samples obtained from mice after *** isolation eliminated interference from other blood components,making it possible to detect exosomal biomarkers for TBI via flow *** cytometry analysis indicated that exosomal biomarkers for TBI increase in the first 24 h following head trauma,indicating the potential of using circulating exosomes for the rapid diagnosis of *** levels of TBI biomarkers were only detected in the samples separated via acoustofluidics;no changes were observed in the analysis of the raw plasma *** finding demonstrated the necessity of sample purification prior to exosomal biomarker *** acoustofluidic exosome separation can easily be integrated with downstream analysis methods,it shows great potential for improving early diagnosis and treatment decisions associated with TBI.

关键词： diagnosis separation injury

来源：评论

学校读者我要写书评

暂无评论

Paramagnon heat capacity and anomalous thermopower in anisotropic magnetic systems: Understanding interlayer spin correlations in a magnetically disordered phase

引用

Physical Review B 2024年第5期109卷 054418-054418页

作者： Fatemeh Heydarinasab Morteza Jazandari Md Mobarak Hossain Polash Jahanfar Abouie Daryoosh Vashaee Department of Physics Faculty of Science University of Sistan and Baluchestan Zahedan 98167-45845 Iran Department of Physics Institute for Advanced Studies in Basic Sciences (IASBS) Zanjan 45137-66731 Iran Department of Materials Science and Engineering North Carolina State University Raleigh North Carolina 27606 USA Department of Electrical and Computer Engineering North Carolina State University Raleigh North Carolina 27606 USA

The interplay between entropy transport and charge carriers–paramagnon interaction in the Onsager linear system has been a subject of debate due to the limited theoretical and experimental understanding of paramagnon heat capacity. In this study, we investigate this interplay in an anisotropic layered magnetic system using cluster mean-field theory with spin quantum correlations. By examining spin correlation functions between different spins with various types of clustering, we derive the spin correlation function as a function of distance and temperature for the interlayer clusters both below and above the magnetic order phase transition. Our analysis reveals that paramagnons characterized by pronounced spin correlations among interlayer nearest-neighbor spins exhibit a nonzero heat capacity, providing valuable insights into the dynamics of entropy transport. The findings align with experimental observations, lending strong support to the validity of the paramagnon-drag thermopower concept. This study sheds light on the intricate dynamics and thermodynamic properties of paramagnons, advancing our understanding of entropy transport in complex systems.

关键词： Entropy Specific heat Spin dynamics Thermoelectric effects

来源：评论

学校读者我要写书评

暂无评论

Beyond Distribution Shift: Spurious Features Through the Lens of Training Dynamics

arXiv

引用

arXiv 2023年

作者： Murali, Nihal Puli, Aahlad Yu, Ke Ranganath, Rajesh Batmanghelich, Kayhan Intelligent Systems Program University of Pittsburgh United States Department of Computer Science New York University United States Department of Electrical and Computer Engineering Boston University United States

Deep Neural Networks (DNNs) are prone to learning spurious features that correlate with the label during training but are irrelevant to the learning problem. This hurts model generalization and poses problems when deploying them in safety-critical applications. This paper aims to better understand the effects of spurious features through the lens of the learning dynamics of the internal neurons during the training process. We make the following observations: (1) While previous works highlight the harmful effects of spurious features on the generalization ability of DNNs, we emphasize that not all spurious features are harmful. Spurious features can be "benign" or "harmful" depending on whether they are "harder" or "easier" to learn than the core features for a given model. This definition is model and dataset dependent. (2) We build upon this premise and use instance difficulty methods (like Prediction Depth (Baldock et al., 2021)) to quantify "easiness" for a given model and to identify this behavior during the training phase. (3) We empirically show that the harmful spurious features can be detected by observing the learning dynamics of the DNN’s early layers. In other words, easy features learned by the initial layers of a DNN early during the training can (potentially) hurt model generalization. We verify our claims on medical and vision datasets, both simulated and real, and justify the empirical success of our hypothesis by showing the theoretical connections between Prediction Depth and information-theoretic concepts like V-usable information (Ethayarajh et al., 2021). Lastly, our experiments show that monitoring only accuracy during training (as is common in machine learning pipelines) is insufficient to detect spurious features. We, therefore, highlight the need for monitoring early training dynamics using suitable instance difficulty metrics. © 2023, CC BY.

关键词： Deep neural networks

来源：评论

学校读者我要写书评

暂无评论

Optimized Transmission Strategy for UAV-RIS 2.0 Assisted Communications Using Rate Splitting Multiple Access

Optimized Transmission Strategy for UAV-RIS 2.0 Assisted Com...

引用

IEEE Conference on Vehicular Technology (VTC)

作者： Aamer Mohamed Huroon Yu-Chih Huang Li-Chun Wang Department of Electrical Engineering and Computer Science International Graduate Program National Yang Ming Chiao Tung University Institute of Communications Engineering National Yang Ming Chiao Tung University Department of Electrical and Computer Engineering National Yang Ming Chiao Tung University

In this paper, we study the transmission strategy of a ground-based beyond diagonal reconfigurable intelligent surface (BD-RIS), a.k.a RIS 2.0, in a network where multiple unmanned aerial vehicles (UAVs) simultaneously transmit signals to the respective groups of users. It is assumed that each group is assigned subcarriers orthogonal to those assigned to other groups and rate splitting multiple access (RSMA) is adopted within each group. A corresponding mixed integer nonlinear programming problem (MINLP) is formulated, which aims to jointly optimize 1) allocation of BD-RIS elements to groups, 2) BD-RIS phase rotations, 3) rate allocation in RSMA, and 4) precoders. To solve the problem, we propose using generalized benders decomposition (GBD) augmented with a manifold-based algorithm. GBD splits the MINLP problem into two sub-problems, namely the primal and the relaxed master problem, which are solved alternately and iteratively. In the primal problem, we apply block coordinate descent (BCD) to manage the coupling of variables effectively. Moreover, we recognize the manifold structure in the phase rotation constraint of BD-RIS, enabling the Riemannian conjugate gradient (RCG). Simulation results demonstrate the effectiveness of the proposed approach in maximizing spectral efficiency.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Enhancement of Antenna Gain With M&W Slot Model on EBG Reflector Structure Utilizing Reflection Phase Diagram Analysis

Enhancement of Antenna Gain With M&W Slot Model on EBG Refle...

引用

13th International electrical engineering Congress, iEECON 2025

作者： Chakunna, Payu Phusam, Nopphadon Mahatthanajatuphat, Pisit Lee, Wilaiporn Suangun, Thanakarn University of Phayao School of Engineering Phayao Thailand Yothinburana School Regular Program in Mathematics-Science Bangkok Thailand King Mongkut's University of Technology North Bangkok Department of Electrical and Computer Engineering Bangkok Thailand

ISBN: (纸本)9798331543952

This research demonstrates the improvement in antenna gain by utilizing an EBG reflector. The EBG reflector includes a unit cell with grooves shaped like the letters M and W to mitigate surface waves at a frequency of 2.45 GHz. The suggested EBG reflector is constructed on an FR-4 substrate exhibiting a uniform dielectric constant of 4.3, a loss tangent of 0.025, and a thickness of 1.6 mm. Furthermore, the impact of boosting the antenna gain can be analyzed by the reflection phase diagram, which exhibits values ranging from +90° to -90° at the resonant frequency of the reflector. The proposed EBG reflector comprises 5x5 unit cells. The testing results of the reflector's performance, when integrated with a general dipole antenna, indicate that it can effectively respond to the resonant frequency of 2.45 GHz, with a |S11| level below -10 dB within the frequency range of 2.2 GHz to 2.6 GHz, thereby adequately covering the IEEE 802.11 b/g/n band. The suggested EBG reflector exhibits a gain of around 6.5 dBi at 2.45 GHz, indicating its efficacy in enhancing gain relative to the standard PEC reflector. Moreover, the radiation pattern is also directional. © 2025 IEEE.

关键词： Antenna reflectors

来源：评论

学校读者我要写书评

暂无评论

LTE/WI-FI COEXISTENCE ON A FLEXIBLE SOFTWARE DEFINED RADIO TESTBED 57

LTE/WI-FI COEXISTENCE ON A FLEXIBLE SOFTWARE DEFINED RADIO T...

引用

57th Annual International Telemetering Conference, ITC 2022

作者： Elahi, Mirza M. Valdez, Kevin J. Gonzalez, Virgilio Computational Science Program The University of Texas at El Paso El PasoTX79968 United States Department of Electrical and Computer Engineering The University of Texas at El Paso El PasoTX79968 United States

The rapid rise in usage of mobile devices have not shown any signs of flattening or slowing down. Some efforts in the standardization bodies are underway to define new ways to boost data rate, network capacity and lower the latency by enhancing existing 4G technologies and by incorporating new technologies in 5G. Since lower spectrum has fewer resources, the LTE of unlicensed spectrum LTE-U is being proposed to extend LTE to unlicensed spectrum. Streaming data traffic for licensed spectrum on LTE-U can improve the performance of the system significantly. In this paper LTE-U deployment by the LAA is implemented using the LBT mechanism on a flexible SDR testbed. © 2022 International Foundation for Telemetering. All rights reserved.

关键词： Testbeds

来源：评论

学校读者我要写书评

暂无评论

engineering dimensionality of collective dipole-dipole interactions using a nanophotonic environment

Engineering dimensionality of collective dipole-dipole inter...

引用

Conference on Lasers and Electro-Optics (CLEO)

作者： Ashwin K. Boddeti Yi Wang Xitlali Juarez Alexandra Boltasseva Hadiseh Alaeian Teri W. Odom Zubin Jacob Elmore Family School of Electrical and Computer Engineering and Birck Nanotechnology Center Purdue University West Lafayette Indiana USA Graduate Program in Applied Physics Northwestern University Evanston IL USA Department of Materials Science and Engineering Northwestern University Evanston Illinois USA Department of Chemistry and Department of Materials Science and Engineering Northwestern University Evanston Illinois USA

We experimentally demonstrate reduced dimensionality in a interacting ensemble of emitters. The well-known stretched exponential decay dynamics, I(t)/I 0 = exp(−γ D t)exp(−αt β ) with β = 0.5 in 3D geometries, is... 详细信息

ISBN: (纸本)9781957171258

关键词： Energy transfer Fluorescence Molecules Spontaneous emission Titanium dioxide

来源：评论

学校读者我要写书评

暂无评论

Micromolded honeycomb scaffold design to support the generation of a bilayered RPE and photoreceptor cell construct

引用

Bioactive materials 2023年第12期30卷 142-153页

作者： In-Kyu Lee Ruosen Xie Agustin Luz-Madrigal Seunghwan Min Jingcheng Zhu Jiahe Jin Kimberly L.Edwards M.Joseph Phillips Allison L.Ludwig David M.Gamm Shaoqin Gong Zhenqiang Ma Department of Electrical and Computer Engineering University of Wisconsin-MadisonMadisonWI53706USA Wisconsin Institute for Discovery University of Wisconsin-MadisonMadisonWI53715USA Department of Ophthalmology and Visual Sciences University of Wisconsin-MadisonMadisonWI53705USA Department of Biomedical Engineering University of Wisconsin-MadisonMadisonWI53706USA McPherson Eye Research Institute University of Wisconsin-MadisonMadisonWI53705USA Waisman Center University of Wisconsin-MadisonMadisonWI53705USA Department of Comparative Biomedical Sciences University of Wisconsin–MadisonMadisonWI53706USA Department of Materials Science and Engineering University of Wisconsin-MadisonMadisonWI53706USA Department of Engineering Physics University of Wisconsin-MadisonMadisonWI53706USA Grainger Institute for Engineering University of Wisconsin-MadisonMadisonWI53706USA

Age-related macular degeneration(AMD)causes blindness due to loss of retinal pigment epithelium(RPE)and photoreceptors(PRs),which comprise the two outermost layers of the *** the small size of the macula and the importance of direct contact between RPE and PRs,the use of scaffolds for targeted reconstruction of the outer retina in later stage AMD and other macular dystrophies is particularly *** developed microfabricated,honeycomb-patterned,biodegradable poly(glycerol sebacate)(PGS)scaffolds to deliver organized,adjacent layers of RPE and PRs to the subretinal ***,an optimized process was developed to photocure PGS,shortening scaffold production time from days to *** resulting scaffolds robustly supported the seeding of human pluripotent stem cell-derived RPE and PRs,either separately or as a dual celllayered *** advanced,economical,and versatile scaffolds can accelerate retinal cell transplantation efforts and benefit patients with AMD and other retinal degenerative diseases.

关键词： Microfabrication Retina Scaffolds Stem cells Tissue engineering

来源：评论

学校读者我要写书评

暂无评论

MULTISCALE PHYSICS-INFORMED NEURAL NETWORKS FOR THE INVERSE DESIGN OF HYPERUNIFORM OPTICAL materials

arXiv

引用

arXiv 2024年

作者： Riganti, Roberto Zhu, Yilin Cai, Wei Torquato, Salvatore Negro, Luca Dal Physics Department Boston University Boston United States Division of Materials Science & Engineering Boston University Boston United States Department of Mathematics Southern Methodist University Dallas United States Department of Chemistry Department of Physics Princeton Materials Institute Princeton University Princeton United States Department of Electrical & Computer Engineering Division of Materials Science & Engineering Physics Department Photonics Center Boston University Boston United States

In this article, we employ multiscale physics-informed neural networks (MscalePINNs) for the inverse design of finite-size photonic materials with stealthy hyperuniform (SHU) disordered geometries. Specifically, we show that MscalePINNs can capture the fast spatial variations of complex fields scattered by arrays of dielectric nanocylinders arranged according to isotropic SHU point patterns, thus enabling a systematic methodology to inversely retrieve their effective dielectric profiles. Our approach extends the recently developed high-frequency homogenization theory of hyperuniform media and retrieves more general permittivity profiles for applications-relevant finite-size SHU systems, unveiling unique features related to their isotropic nature. In particular, we numerically corroborate the existence of a transparency region beyond the long-wavelength approximation, enabling effective and isotropic homogenization even without disorder-averaging, in contrast to the case of uncorrelated Poisson random patterns. The flexible multiscale network approach introduced here enables the efficient inverse design of more general effective media and finite-size optical metamaterials with isotropic electromagnetic responses beyond the limitations of traditional homogenization theories. Copyright © 2024, The Authors. All rights reserved.

关键词： Inverse problems

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：