检索结果-内蒙古大学图书馆

European Physical Journal E 2024年第6期47卷 1-4页

作者： Andelman, David Di Meglio, Jean-Marc Safinya, Cyrus R. Tel Aviv University School of Physics and Astronomy Ramat Aviv Tel Aviv69978 Israel MSCmed Lab Université Paris Cité Paris75006 France Materials Department Molecular Cellular and Developmental Biology Department Department of Physics and Biomolecular Science & ampEngineering Program University of California Santa Barbara Santa BarbaraCA93106 United States

来源：评论

学校读者我要写书评

暂无评论

Cross Interpolation for Solving High-Dimensional Dynamical Systems on Low-Rank Tucker and Tensor Train Manifolds

arXiv

引用

arXiv 2024年

作者： Ghahremani, Behzad Babaee, Hessam Department of Mechanical Engineering and Materials Science University of Pittsburgh 3700 O’Hara Street PittsburghPA15213 United States

We present a novel tensor interpolation algorithm for the time integration of nonlinear tensor differential equations (TDEs) on the tensor train and Tucker tensor low-rank manifolds, which are the building blocks of many tensor network decompositions. This paper builds upon our previous work (Donello et al., Proceedings of the Royal Society A, Vol. 479, 2023 [1]) on solving nonlinear matrix differential equations on low-rank matrix manifolds using CUR decompositions. The methodology we present offers multiple advantages: (i) It delivers near-optimal computational savings both in terms of memory and floating-point operations by leveraging cross algorithms based on the discrete empirical interpolation method to strategically sample sparse entries of the time-discrete TDEs to advance the solution in low-rank form. (ii) Numerical demonstrations show that the time integration is robust in the presence of small singular values. (iii) High-order explicit Runge-Kutta time integration schemes are developed. (iv) The algorithm is easy to implement, as it requires the evaluation of the full-order model at strategically selected entries and does not use tangent space projections, whose efficient implementation is intrusive. We demonstrate the efficiency of the presented algorithm for several test cases, including a nonlinear 100-dimensional TDE for the evolution of a tensor of size 70100 ≈ 3.2 × 10184 and a stochastic advection-diffusion-reaction equation with a tensor of size 4.7 × 109 © 2024, CC0.

关键词： Tensors

来源：评论

学校读者我要写书评

暂无评论

A DEIM Tucker Tensor Cross Algorithm and its Application to Dynamical Low-Rank Approximation

arXiv

引用

arXiv 2024年

作者： Ghahremani, Behzad Babaee, Hessam Department of Mechanical Engineering and Materials Science University of Pittsburgh 3700 O'Hara Street PittsburghPA15213 United States

We introduce a Tucker tensor cross approximation method that constructs a low-rank representation of a d-dimensional tensor by sparsely sampling its fibers. These fibers are selected using the discrete empirical interpolation method (DEIM). Our proposed algorithm is referred to as DEIM fiber sampling (DEIM-FS). For a rank-r approximation of an O(Nd) tensor, DEIM-FS requires access to only dNrd−1 tensor entries, a requirement that scales linearly with the tensor size along each mode. We demonstrate that DEIM-FS achieves an approximation accuracy close to the Tucker-tensor approximation obtained via higher-order singular value decomposition at a significantly reduced cost. We also present DEIM-FS (iterative) that does not require access to singular vectors of the target tensor unfolding and can be viewed as a black-box Tucker tensor algorithm. We employ DEIM-FS to reduce the computational cost associated with solving nonlinear tensor differential equations (TDEs) using dynamical low-rank approximation (DLRA). The computational cost of solving DLRA equations can become prohibitive when the exact rank of the right-hand side tensor is large. This issue arises in many TDEs, especially in cases involving non-polynomial nonlinearities, where the right-hand side tensor has full rank. This necessitates the storage and computation of tensors of size O(Nd). We show that DEIM-FS results in significant computational savings for DLRA by constructing a low-rank Tucker approximation of the right-hand side tensor on the fly. Another advantage of using DEIM-FS is to significantly simplify the implementation of DLRA equations, irrespective of the type of TDEs. We demonstrate the efficiency of the algorithm through several examples including solving high-dimensional partial differential equations. © 2024, CC0.

关键词： Tensors

来源：评论

学校读者我要写书评

暂无评论

Facile assembly of flexible,stretchable and attachable symmetric microsupercapacitors with wide working voltage windows and favorable durability

引用

Microsystems & Nanoengineering 2024年第4期10卷 297-304页

作者： Xiangguang Han Xiaoyu Wu Libo Zhao Min Li Chen Jia Zhikang Li Jiaqi Xie Guoxi Luo Ping Yang Rabah Boukherroub Yurdanur Türker Mert UmutÖzkaynak Koray Bahadır Dönmez State Key Laboratory for Manufacturing Systems Engineering International Joint Laboratory for Micro/Nano Manufacturing and Measurement TechnologiesXi’an Jiaotong University(Yantai)Research Institute for Intelligent Sensing Technology and SystemXi’an Jiaotong UniversityXi’an 710049China School of Instrument Science and Technology Xi’an Jiaotong UniversityXi’an 710049China Shandong Laboratory of Advanced Materials and Green Manufacturing at Yantai Yantai 264000China School of Mechanical Engineering Xi’an Jiaotong UniversityXi’anShaanxi 710049China Chongqing Key Laboratory of Micro-Nano Systems and Intelligent Sensing Chongqing Academician WorkstationChongqing 2011 Collaborative Innovation Center of Micro/Nano Sensing and Intelligent Ecological Internet of ThingsChongqing Technology and Business UniversityNan’an DistrictChongqing 400067China Univ.Lille CNRSUniv.Polytechnique Hauts-de-FranceUMR 8520-IEMNF-59000 LilleFrance Sabanci University Nanotechnology Research and Application Center(SUNUM) IstanbulTurkey Department of Materials Science and Engineering Istanbul Technical UniversityIstanbulTurkey

With the increasing development of intelligent robots and wearable electronics,the demand for high-performance flexible energy storage devices is drastically *** this study,flexible symmetric microsupercapacitors(MSCs)that could operate in a wide working voltage window were developed by combining laser-direct-writing graphene(LG)electrodes with a phosphoric acid-nonionic surfactant liquid crystal(PA-NI LC)gel *** increase the flexibility and enhance the conformal ability of the MSC devices to anisotropic surfaces,after the interdigitated LG formed on the polyimide(PI)film surface,the devices were further transferred onto a flexible,stretchable and transparent polydimethylsiloxane(PDMS)substrate;this substrate displayed favorable flexibility and mechanical characteristics in the bending ***,the electrochemical performances of the symmetric MSCs with various electrode widths(300,400,500 and 600μm)were *** findings revealed that symmetric MSC devices could operate in a large voltage range(0–1.5 V);additionally,the device with a 300μm electrode width(MSC-300)exhibited the largest areal capacitance of 2.3 mF cm^(−2)at 0.07 mA cm^(−2)and an areal(volumetric)energy density of 0.72μWh cm−2(0.36 mWh cm^(−3))at 55.07μWcm−2(27.54mWcm−3),along with favorable mechanical and cycling *** charging for~20 s,two MSC-300 devices connected in series could supply energy to a calculator to operate for~130 s,showing its practical application potential as an energy storage ***,the device displayed favorable reversibility,stability and *** 12 months of aging in air at room temperature,its electrochemical performance was not altered,and after charging-discharging measurements for 5000 cycles at 0.07 mA cm^(−2),~93.6%of the areal capacitance was still retained;these results demonstrated its practical long-term application potential as an energy storage device.

关键词： cycling durability electrode

来源：评论

学校读者我要写书评

暂无评论

Modelling of δ-ferrite Transformation Effect On The Sintering Behaviour Of 316L Binder Jetted Components

Modelling of δ-ferrite Transformation Effect On The Sinteri...

引用

World PM 2022 Congress and Exhibition

作者： Rios, Alberto Cabo Olevsky, Eugene Hryha, Eduard Persson, Mats Department of Industrial and Materials Science Chalmers University of Technology Sweden Mechanical Engineering San Diego State University United States Digital Metal AB Sweden

ISBN: (纸本)9781899072552

The main objective of this study is to develop a simulation methodology that accounts for phase transformation (δ-ferrite) during the sintering of 316L stainless steel binder jetted (BJ) components. The model was based on the continuum theory of sintering develop by Skorohod and Olevsky. Dilatometry sintering tests at different heating rates up to 1370°C were performed. The constitutive parameters for the sintering model were obtained by dilatometry data analysis. Dilatometry results at different heating rates showed minor influence of the δ-ferrite transformation kinetics on the material viscosity. Thus, a new temperature-dependent material viscosity function was proposed to include the δ-ferrite transformation. The new model proposed was used to predict the densification behaviour of 316L BJ samples subjected to dilatometry experiments at different temperatures and times. The influence of δ-ferrite on the densification was accurately predicted for the material and sintering conditions studied. © European Powder Metallurgy Association (EPMA)

关键词： Sintering

来源：评论

学校读者我要写书评

暂无评论

Effect of Final Rolling Deformation on Microstructure, Work Hardening and Softening Behavior of Mg-8li-3al-0.3si Alloys

SSRN

引用

SSRN 2024年

作者： Li, Ya-Niu Deng, Kun-Kun Wang, Cui-Ju Nie, Kai-Bo Shi, Quan-Xin Tian, Peng-Cheng Zhang, Guo-Wei Shanxi Key Laboratory of advanced magnesium-based materials College of Materials Science and Engineering Taiyuan University of Technology Taiyuan030024 China Key Laboratory of Interface Science and Engineering in Advanced Materials Ministry of Education Taiyuan University of Technology Taiyuan030024 China College of mechanical engineering Ningbo University of Technology Ningbo315211 China

In the present work, Al-27Si alloy was prepared using spray deposition and subsequently incorporated into Mg-Li alloy via a vacuum melting technique to produce a novel Mg-8Li-3Al-0.3Si (LA83-0.3Si) duplex alloy. This alloy underwent rolling at 250 °C, and the effect of final rolling deformation (30%, 40%, 50% and 60%, respectively) on microstructure, mechanical properties, work hardening and softening behavior were studied. The as-cast LA83-0.3Si alloy consists of α-Mg, β-Li, AlLi and Mg2Si phases. Rolling deformation elongated the α-Mg and β-Li phases in the rolling direction, promoting an α/β laminar structure, notably enhancing the strength and ductility. Incremental rolling deformation led to heightened aspect ratios of α-Mg and β-Li phases. This resulted in a more pronounced α/β laminated arrangement and the downsizing and numerical increase of precipitates. Consequently, the alloy's strength progressively increased while ductility slightly diminished. At 60% deformation, tensile strength of the LA83-0.3Si alloy reached 331 MPa, with the elongation sustained at 10.9%. The rolling process reduced the work hardening rate and increased the softening rate. As deformation increased, the work hardening rate decreased, and the softening rate is further improved. However, at 60% deformation, the work hardening rate increases and the softening rate decreases due to the decrease of the hardness ratio of α-Mg and β-Li phase. © 2024, The Authors. All rights reserved.

关键词： Binary alloys

来源：评论

学校读者我要写书评

暂无评论

Correlating the Ambient Conditions and Performance Indicators of the LoRaWAN via Surrogate Gaussian Process-Based Bidirectional LSTM Stacked Autoencoder

引用

IEEE Transactions on Network and Service Management 2023年第3期20卷 3413-3427页

作者： Bhat, Showkat Ahmad Huang, Nen-Fu Hussain, Imtiyaz Sajjad, Uzair National Tsing Hua University College of Electrical and Computer Science Hsinchu1300044 Taiwan National Tsing Hua University Department of Computer Science Hsinchu1300044 Taiwan National Taipei University of Technology Graduate Program in Energy and Opto-Electronic Materials Taipei10608 Taiwan National Taipei University of Technology Department of Energy and Refrigerating Airconditioning Engineering Taipei10608 Taiwan

LoRa's biggest advantage is its flexibility, which is the ability to increase or decrease data rate and range while decreasing or increasing sensitivity. Whenever propagation conditions change frequently, this function allows the spreading factor to be modified accordingly. Despite their efficiency and scalability, adaptive data rate algorithms ignore and fail to factor in the complex correlation between ambient weather parameters influencing the communication channel design. In this research, a Bayesian surrogate Gaussian process-based bidirectional LSTM stacked autoencoder model (BSGP-BLSTM-SAE) is proposed to estimate the channel performance indicators such as received signal strength indicator (RSSI) and signal-to-noise ratio (SNR) and to determine the correlation between the ambient weather conditions and performance indicators for the LoRaWAN network. Bayesian optimization algorithm has been used to optimize the hyper-parameters of the developed model. A LoRaWAN experimental multivariate time series dataset has been used for the evaluation of the developed model, which upon testing and validation produces high accuracy in predicting the channel performance indicators and ambient conditions of the experimental LoRaWAN network. The mean absolute error of the developed model was around 0.45. Thus, the proposed model can predict the link performance indicators and thereby assist in real-time optimization of the transmission parameters to enhance the network performance in LoRaWAN-based systems at different ambient conditions. © 2004-2012 IEEE.

关键词： Internet of things

来源：评论

学校读者我要写书评

暂无评论

Effect of vacuum heat treatment on microstructure evolution and oxidation behavior of arc ion plated AlCoCrFeNiYHf high entropy alloy coatings

引用

materials Characterization 2025年 227卷

作者： Zhu, Jingjing Li, Xiangcheng Lyu, Peng Hua, Yinqun Lu, Jinzhong Cai, Jie Institute of Advanced Manufacturing and Modern Equipment Technology Jiangsu University Zhenjiang212013 China School of Mechanical Engineering Jiangsu University Zhenjiang212013 China School of Materials Science and Engineering Jiangsu University Zhenjiang212013 China

This study used the arc ion plating (AIP) method to deposit an AlCoCrFeNiYHf high-entropy alloy (HEA) layer on a Ni-based superalloy. The effects of vacuum heat treatment (VHT) on the resistance of the HEA coatings to high-temperature oxidation, phase transitions, and microstructural evolution by adjusting the coatings to VHT at several different temperatures (800, 900, 1000, and 1050 °C) with varying VHT parameters were investigated. The findings imply that the deposited AlCoCrFeNiYHf HEA coatings consist of Fe[sbnd]Cr rich (A2) and Al[sbnd]Ni rich (B2) phases, which together form a single BCC phase. After VHT, there is a noticeable phase change at all temperatures from a BCC structure to an FCC structure. Notably, a brittle σ-phase is generated in the coating treated at 800, 900 and 1000 °C, but is absent in the coating treated at 1050 °C. In addition, heat treatment at 1050 °C results in the formation and precipitation of a significant quantity of Y[sbnd]Al nanoparticles that become dispersed throughout the coatings. The results regarding resistance to high-temperature oxidation reveal a significant reduction in weight gain from oxidation for the coatings that underwent VHT. Notably, the HEA coatings treated at 1050 °C demonstrate superior oxidation resistance due to the formation of a uniform, continuous and dense layer of Al oxide on its surface, which effectively prevents further interaction with oxygen or other corrosive substances. The optimal heat treatment parameters for the HEA coatings are 1050 °C for a duration of 4 h. © 2025 Elsevier Inc.

关键词： Aluminum coatings

来源：评论

学校读者我要写书评

暂无评论

A preliminary data fusion study to assess the feasibility of Foundation Process-Property Models in Laser Powder Bed Fusion

arXiv

引用

arXiv 2025年

作者： Vendrell-Gallart, Oriol Negarandeh, Nima Foumani, Zahra Zanjani Amiri, Mahsa Valdevit, Lorenzo Bostanabad, Ramin Department of Mechanical and Aerospace Engineering University of California IrvineCA92697 United States Materials and Manufacturing Technology Program University of California IrvineCA92697 United States Department of Materials Science and Engineering University of California IrvineCA92697 United States Department of Civil and Environmental Engineering University of California IrvineCA92697 United States

Foundation models are at the forefront of an increasing number of critical applications. In regards to technologies such as additive manufacturing (AM), these models have the potential to dramatically accelerate process optimization and, in turn, design of next generation materials. A major challenge that impedes the construction of foundation process-property models is data scarcity. To understand the impact of this challenge, and since foundation models rely on data fusion, in this work we conduct controlled experiments where we focus on the transferability of information across different material systems and properties. More specifically, we generate experimental datasets from 17-4 PH and 316L stainless steels (SSs) in Laser Powder Bed Fusion (LPBF) where we measure the effect of five process parameters on porosity and hardness. We then leverage Gaussian processes (GPs) for process-property modeling in various configurations to test if knowledge about one material system or property can be leveraged to build more accurate machine learning models for other material systems or properties. Through extensive cross-validation studies and probing the GPs’ interpretable hyperparameters, we study the intricate relation among data size and dimensionality, complexity of the process-property relations, noise, and characteristics of machine learning models. Our findings highlight the need for structured learning approaches that incorporate domain knowledge in building foundation process-property models rather than relying on uninformed data fusion in data-limited applications. © 2025, CC BY.

关键词： Data fusion

来源：评论

学校读者我要写书评

暂无评论

Cooling of Semiconductor Devices via Quantum Tunneling

引用

Physical Review Letters 2024年第26期133卷 266301-266301页

作者： Amin Reihani Zheng Li Jian Guan Yuxuan Luan Shen Yan Jin Xue Edgar Meyhofer Pramod Reddy Rajeev J. Ram Department of Mechanical Engineering University of Michigan Ann Arbor Michigan 48109 USA Research Laboratory of Electronics Massachusetts Institute of Technology Cambridge Massachusetts 02139 USA Department of Materials Science and Engineering University of Michigan Ann Arbor Michigan 48109 USA

Classical transport of electrons and holes in nanoscale devices leads to heating that severely limits performance, reliability, and efficiency. In contrast, recent theory suggests that interband quantum tunneling and subsequent thermalization of carriers with the lattice results in local cooling of devices. However, internal cooling in nanoscale devices is largely unexplored. Here, using a novel scanning thermal microscopy technique with millikelvin temperature resolution and nanometer spatial resolution, we directly record the cross-sectional temperature in functional InGaAs tunnel diodes. Our measurements reveal large, localized cooling of 2–3 W/cm2 at the tunnel junction, which is in quantitative agreement with the bipolar Peltier process associated with interband tunneling. These advances hold significant potential for integration into electronic and energy conversion devices and improving their performance.

关键词： Tunnel diodes

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：