检索结果-内蒙古大学图书馆

arXiv 2022年

作者： Qin, Mingde Shivakumar, Sashank Luo, Jian Department of NanoEngineering Program of Materials Science and Engineering University of California San Diego La Jolla CA92093 United States

Nanocrystalline alloys (nanoalloys) are prone to grain growth. It is known that grain boundary segregation and precipitation can stabilize nanoalloys, but the stabilization becomes less effective at high temperatures and adding grain growth inhibitors often reduces sinterability. Herein, we have simultaneously achieved improved sinterability and exceptional high-temperature stability for a class of MoNbTaTiW-based refractory high-entropy nanoalloys (RHENs). Bulk pellets of RHENs were fabricated through planetary ball milling and spark plasma sintering, achieving 93-96% relative densities with 50-100 nm grain sizes for three compositions. For example, Mo17.8Nb17.8Ta17.8Ti17.8W17.8Ni6Zr5 sintered at 1300 °C attained ~96% relative density with ~55 nm mean grain size. Moreover, these RHENs exhibited exceptional stability at 1300 °C. Both Ti17.8Nb17.8Mo17.8Ta17.8W17.8Ni6Zr5 and Mo18.8Nb18.8Ta18.8Ti18.8W18.8Ni6 retained 96% of the theoretical densities after five hours annealing at 1300 °C. Notably, the addition of Ni, a well-known sintering aid for activated sintering of refractory metals such as W and Mo, in high-entropy MoNbTaTiW can promote sintering while maintaining high-temperature stability against rapid grain growth, which can be explained by hypothesized effects of high-entropy grain boundaries. These RHENs possess some of the highest temperature stability achieved for nanoalloys and ultrafine-grained metals. © 2022, CC BY.

关键词： Grain boundaries

来源：评论

学校读者我要写书评

暂无评论

Ultra-high sensitive 2D photonic crystal for gas and chemical sensing applications

Ultra-high sensitive 2D photonic crystal for gas and chemica...

引用

Optical Sensors 2023

作者： Salama, Norhan A. Swillam, Mohamed A. Hameed, Mohamed Farhat O. Alexeree, Shaimaa M. Obayya, Salah S.A. Laser Applications in Metrology Photochemistry and Agriculture National Institute of Laser Enhanced Sciences Cairo University Giza Egypt Department of Physics The American University in Cairo Cairo11835 Egypt Centre for Photonics and Smart Materials Zewail City of Science Technology and Innovation October Gardens 6th of October City Giza12578 Egypt Nanotechnology and Nanoelectronics Engineering Program Zewail City of Science Technology and Innovation October Gardens 6th of October City Giza12578 Egypt Faculty of Engineering University of Mansoura Mansoura Egypt

ISBN: (数字)9781510662650

ISBN: (纸本)9781510662643

Mid infrared (MID-IR) band of electromagnetic radiation plays the key role for gas and chemical sensing application because it provides molecular fingerprints for most trace gases and molecules. Photonic crystal cavity coupled waveguide (PC-CWG) based sensors is a remarkable platform for sensing applications due to its capability to confine light modes on small volume displaying high sensitivity and high quality factors. In this work, we report a novel design of (PC-CWG) based on square lattice of silicon pillars in air with radius of 0.2μm and lattice constant of 1 μm. A waveguide is introduced by removing three columns of silicon pillars, and a microcavity is created by removing a number of silicon pillars forming curved shapes on both sides of the waveguide. The proposed design demonstrates multiple resonances covering a broad spectral range in MID-IR ranging from 2.4 μm to 4.2 μm that represents the bandgap region. Remarkable resonances are observed at operating wavelengths 2.67 μm, 2.88 μm, 3.03 μm, 3.2 μm and 3.5 μm. Moreover, the reported design shows ultra-high sensitivity reaching 2680 nm/RIU with a significant quality factor of Q=6475 giving rise to a figure-of-merit of 5.7 × 106 at the operating wavelength of (λ=3.03μm). The suggested photonic crystal design offers simple fabrication and broad applicability for refractive index sensing applications. © 2023 SPIE.

关键词： Photonic crystals

来源：评论

学校读者我要写书评

暂无评论

Meta-optic accelerators for object classifier

Meta-optic accelerators for object classifier

引用

Conference on Lasers and Electro-Optics (CLEO)

作者： Hanyu Zheng Quan Liu You Zhou Ivan I. Kravchenko Yuankai Huo Jason Valentine Department of Electrical and Computer Engineering Vanderbilt University Nashville TN USA Department of Computer Science Vanderbilt University Nashville TN USA Interdisciplinary Materials Science Program Vanderbilt University Nashville TN USA Center for Nanophase Materials Sciences Oak Ridge National Laboratory Oak Ridge TN USA Department of Mechanical Engineering Vanderbilt University Nashville TN USA

A meta-optic platform for accelerating object classification is demonstrated. End-to-end design is used to co-optimize the optical and digital systems resulting in a high-speed and robust classifier with 93.1% accurac... 详细信息

ISBN: (纸本)9781957171258

关键词： Image analysis Image resolution Machine vision Neural networks Optical systems Signal processing

来源：评论

学校读者我要写书评

暂无评论

engineering Andreev Bound States for Thermal Sensing in Proximity Josephson Junctions

arXiv

引用

arXiv 2025年

作者： Jung, Woochan Arnault, Ethan G. Huang, Bevin Park, Jinho Jang, Seong Watanabe, Kenji Taniguchi, Takashi Englund, Dirk Fong, Kin Chung Lee, Gil-Ho Physics Department Pohang University of Science and Technology Pohang37673 Korea Republic of Research Laboratory of Electronics Massachusetts Institute of Technology CambridgeMA02139 United States Intelligence Community Postdoctoral Research Fellowship Program Massachusetts Institute of Technology CambridgeMA02139 United States Department of Mechanical Engineering Columbia University New YorkNY10027 United States Research Center for Functional Materials National Institute for Materials Science Tsukuba Japan International Center for Materials Nanoarchitectonics National Institute for Materials Science Tsukuba Japan Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology CambridgeMA02139 United States Department of Electrical and Computer Engineering Northeastern University BostonMA02115 United States Department of Physics Northeastern University BostonMA02115 United States Quantum Materials and Sensing Institute BurlingtonMA01803 United States

The thermal response of proximity Josephson junctions (JJs) is governed by the temperature (T)- dependent occupation of Andreev bound states (ABS), making them promising candidates for sensitive thermal detection. In this study, we systematically engineer ABS to enhance the thermal sensitivity of critical current (lc) of proximity JJs, quantified as |dlc/dT/| for threshold readout scheme and |dlc/***−1| for inductive readout scheme. Using a gate-tunable graphene-based JJ platform, we explore the impact of key parameters—including channel length, transparency, carrier density, and superconducting material—on the thermal response. Our results reveal that the proximity-induced superconducting gap plays a crucial role in optimizing thermal sensitivity. Notably, we see a maximum |dlc/***−1| value of 0.6 K−1 at low temperatures with titanium-based graphene JJs. By demonstrating a systematic approach to engineering ABS in proximity JJs, this work establishes a versatile framework for optimizing thermal sensors and advancing the study of ABS-mediated transport. © 2025, CC BY.

关键词： Superconducting materials

来源：评论

学校读者我要写书评

暂无评论

MOF-catalyzed hydroxyalkylation-alkylation reaction for the controlled synthesis of furan oligomers

引用

Applied Catalysis A: General 2024年 669卷

作者： Atayde, Eduardo C. Matsagar, Babasaheb M. Wang, Yu-Cheng Wu, Kevin C.-W. Molecular Science and Technology Program Taiwan International Graduate Program Academia Sinica No. 128 Sec. 2 Academia Road Taipei11529 Taiwan Department of Chemistry National Tsing Hua University No. 101 Sec. 2 Kuang-Fu Road Hsinchu30013 Taiwan Department of Chemical Engineering National Taiwan University No. 1 Sec. 2 Roosevelt Road Taipei10617 Taiwan Department of Chemical Engineering and Materials Science Yuan Ze University Taoyuan Chung-Li Taiwan

Hydroxyalkylation-alkylation (HAA) reaction is a type of C-C coupling technique utilized in the production of furan oligomers, which are potential biofuel precursors. In this study, we present the first application of an acidic MOF, Sulfated MOF-808, in catalyzing the HAA reactions of a series of furan oligomers with high yield and selectivity. Specifically, we focused on the optimization of the HAA between 5-methylfurfural (5-MFUR) and 2-methylfuran (2-MF) by varying different reaction conditions, which afforded a quantitative yield reaching 97% while preventing the self-condensation of 2-MF. The catalyst was also found to be recyclable and can be reused without significant loss in its activity. Lastly, we extended the substrate scope to include benzene-based electrophiles, thereby further proving the versatility of the Sulfated MOF-808 catalyst in the HAA reactions of a variety of starting materials. © 2023 Elsevier B.V.

关键词： Catalysis

来源：评论

学校读者我要写书评

暂无评论

Monolithic Germanium–Tin on Si Avalanche Photodiodes

arXiv

引用

arXiv 2024年

作者： Rudie, Justin Amoah, Sylvester Wang, Xiaoxin Kumar, Rajesh Abernathy, Grey Akwabli, Steven Grant, Perry C. Liu, Jifeng Li, Baohua Du, Wei Yu, Shui-Qing Material Science and Engineering University of Arkansas FayettevilleAR72701 United States Department of Electrical Engineering and Computer Science University of Arkansas FayettevilleAR72701 United States Thayer School of Engineering Dartmouth College HanoverNH03755 United States Arktonics LLC 1339 S. Pinnacle Dr. FayettevilleAR72701 United States Materials Science & Engineering Program University of Arkansas FayettevilleAR72701 United States Institute for Nanoscience and Engineering University of Arkansas FayettevilleAR72701 United States

We demonstrate monolithically grown germanium-tin (GeSn) on silicon avalanche photodiodes (APDs) for infrared light detection. A relatively thinner Ge buffer design was adopted to allow effective photo carriers to transport from the GeSn absorber to the Si multiplication layer such that clear punch-through behavior and a saturated primary responsivity of 0.3 A/W at 1550 nm were observed before avalanche breakdown in GeSn/Si APDs for the first time. The spectral response covers 1500 to 1700 nm. The measured punch-through and breakdown voltages are 15 and 17 V, respectively. Undisputed multiplication gain was obtained with the maximum value of 4.5 at 77 K, and 1.4 at 250 K, directly in reference to the saturated primary responsivity from the same device rather than a different GeSn p-i-n photodiode in previous reports. A peak responsivity was measured as 1.12 A/W at 1550 nm and 77 K. © 2024, CC0.

关键词： Avalanche photodiodes

来源：评论

学校读者我要写书评

暂无评论

Large magnetic anisotropy and magnetostriction in thin films of CoV2O4

引用

Physical Review materials 2023年第1期7卷 014408-014408页

作者： Sangsoo Kim Christie J. Thompson Yan Xin Christianne Beekman National High Magnetic Field Laboratory Florida State University Tallahassee Florida 32310 USA Department of Physics Florida State University Tallahassee Florida 32306 USA Materials Science and Engineering Program Florida State University Tallahassee Florida 32310 USA

Spinel cobalt vanadate CoV2O4 has been grown on (001) SrTiO3 substrates. Using torque magnetometry experiments, we find that the previously observed temperature-induced anisotropy change, where the easy axis changes from the out-of-plane [001] direction to a biaxial anisotropy with planar <100> easy axes, occurs in a gradual second-order structural phase transition. This paper characterizes this transition and the magnetic anisotropies in the (001), (100), and (1¯10) rotation planes, and explores their field dependence up to 30 T. Below 80 K, hysteretic features appear around the hard axes, i.e., the out-of-plane direction in (1¯10) and (010) rotations and the planar <110> directions in (001) rotations. This is due to a Zeeman energy that originates from the lag of the magnetization with respect to the applied magnetic field as the sample is rotated. The appearance of the hysteresis, which persists up to very high fields, shows that the anisotropy at low temperature is rather strong. Additionally, field-dependent distortions to the symmetry of the torque response in increasing applied fields shows that magnetostriction plays a large role in determining the direction and magnitude of the anisotropy.

关键词： Magnetic anisotropy Magnetic phase transitions Structural properties

来源：评论

学校读者我要写书评

暂无评论

Alternating Cu segregation and its stabilization mechanism for coherent η' precipitates in Al–Zn–Mg–Cu alloys

引用

materials Today Advances 2024年 23卷

作者： Chiu, Yu-ning Chung, Tsai-fu Yen, Shao-yu Yu, Chung-yi Lin, Wei-ting Hsieh, Chia-chia Lin, Shih-kang Department of Materials Science and Engineering National Cheng Kung University Tainan70101 Taiwan Department of Materials Science and Engineering National Yang Ming Chiao Tung University Hsinchu30010 Taiwan Aluminum Prod R&D Section New Materials R&D Department Kaohsiung81233 Taiwan Research Center National Cheng Kung University Tainan70101 Taiwan Program on Smart and Sustainable Manufacturing Academy of Innovative Semiconductor and Sustainable Manufacturing National Cheng Kung University Tainan70101 Taiwan Core Facility Center National Cheng Kung University Tainan70101 Taiwan

The 7000 series (Al–Zn–Mg) Al-alloys are renowned for their exceptional "lightweight-high strength" properties, primarily owing to nano-sized meta-stable η′ precipitate as the main strengthening phase. However, these η′ precipitates are susceptible to transforming into the stable η2 phase at elevated temperatures, resulting in a decline in strength. To mitigate this, Cu-segregation has been long proposed as a promising method for stabilizing these meta-stable precipitates. However, the mechanisms involved have not been fully understood. In this study, we conducted a thorough investigation on the structural and energetic changes between Cu-free and Cu-segregated η' and η2 precipitates. Utilizing DFT calculations and HAADF-STEM characterizations, we uncovered a distinctive alternating Cu-segregation pattern. This pattern induces significant structural modifications within the bulk of η' precipitates and at the precipitate-matrix interface, markedly enhancing their interfacial and bulk energetics. We believe these modifications are the key factor in improving precipitate stability. Based on our findings, the underlying mechanism of solute segregation was elucidated and a novel strategy for optimal design of Al–Zn–Mg alloys was proposed. © 2024 The Authors

关键词： High strength alloys

来源：评论

学校读者我要写书评

暂无评论

Development of Flame Retardant Stearic Acid Doped Graphite Powder and Magnesium Hydroxide Nanoparticles, Material for Thermal Energy Storage Applications 21

Development of Flame Retardant Stearic Acid Doped Graphite P...

引用

21st International Union of materials Research Societies International Conference in Asia, IUMRS-ICA 2021

作者： Han, Kyaw Thet Lhosupasirirat, Siraprapa Srikhirin, Pongsid Houngkamhang, Nongluck Srikhirin, Toemsak Materials Science and Engineering Program School of Materials Science and Innovation Faculty of Science Mahidol University Bangkok10400 Thailand Ramkhamhaeng University Bangkok Thailand College of Nanotechnology King Mongkut's Institute of Technology Ladkrabang Bangkok10520 Thailand Research Network of NANOTEC Mahidol University National Nanotechnology Center Thailand Department of Physics Faculty of Science Mahidol University 272 Rama VI Road Ratchathewi District Bangkok10400 Thailand

Nano-enhanced organic phase change material (PCM) composite consists of stearic acid (SA, act as the thermal storage media), graphite powder(GP, function as thermal conductor), and magnesium hydroxide nanoparticles(nMH), micro-sized (MMH), function as the flame retarder), were formulated and investigated for their thermophysical properties and flammability. The flame-retardant properties of nano-enhanced composite PCM were evaluated by using the burning test. Phase change temperature, phase change latent heat, and thermal conductivity were obtained by the T-history method. To reduce the flammability, 5wt% of MH with 0.8µm and 200nm were added to PCMs. 1wt% of GP improved thermal conductivity of stearic acid from 0.245 to 0.4887 W/mk, and doping of flame-retardant nanoparticles to PCM showed the reduction of flammability and slightly effecting on latent heat of PCM. nMH were found to work better for stearic acid flammability than MMH, where combustion time of 0.1g pure stearic acid(SA) was decreased from 41s to 17s and 23s. For nano-sized(SA/nMH) and micron-sized(SA/MMH)composites, the latent heat of pure PCM dropped from 171.26 to 124.85KJ/kg, but micron-sized addition negatively affects latent heat values by reducing from 171.26 to 88.87 KJ/kg. The results confirmed that nMH/GP/SA composite could reduce flammability without showing a negative impact on storage capacity. © Published under licence by IOP Publishing Ltd.

关键词： Phase change materials

来源：评论

学校读者我要写书评

暂无评论

Thermodynamics of the Solid-Liquid Phase Equilibrium of a Binary System: Effect of a Chemical Reaction in the Liquid and Epitaxial Strain in the Solid

SSRN

引用

SSRN 2023年

作者： Deymier, Alix C. Deymier, Pierre Alix Muralidharan, Krishna Latypov, Marat I. Department of Biomedical Engineering UConn Health FarmingtonCT06030 United States Department of Materials Science and Engineering University of Arizona TucsonAZ85721 United States Graduate Interdisciplinary Program in Applied Mathematics University of Arizona TucsonAZ85721 United States

We introduce two thermodynamics models of solid-liquid phase equilibrium of a binary system in the presence of (a) a chemical reaction in the liquid involving only one of the binary components and, (b) strain-inducing epitaxial conditions on the solid in addition to the chemical reaction in the liquid. These models show the existence of the counter intuitive behavior that epitaxy may promote recrystallization of the solid in spite of the reaction driving dissolution. The conditions for this recrystallization behavior are determined by the value of the epitaxial lattice matching composition, the temperature and the overall composition of the binary solid-liquid system. © 2023, The Authors. All rights reserved.

关键词： Chemical reactions

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：