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Effects of Hf Addition on the Microstructure and Properties of Cu-Sn-P Alloy

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SSRN 2024年

作者： Wei, Biao Yang, Haoren Wang, Chen Zhou, Jianhui Xiao, Lei Ma, Tianyu Wang, Bingshu College of Materials Science and Engineering Fuzhou University Fuzhou350108 China Fujian Zijin Copper Co. Ltd. Longyan364200 China Frontier Institute of Science and Technology State Key Laboratory for Mechanical Behavior of Materials Xi'an Jiaotong University Xian710049 China School of Materials Science and Engineering China

In this paper, the effects of Hf addition on the mechanical properties, electrical conductivity and microstructure of Cu-Sn-P alloy were investigated. The results show that the Hf addition can enhance the mechanical properties and electrical conductivity of Cu-Sn-P alloy. The alloy with 0.05 wt.% Hf exhibits the best comprehensive performance with yield strength of 624.68 MPa, tensile strength of 661.13 MPa and electrical conductivity of 16.8%IACS. Compared with the Cu-Sn-P alloy without Hf addition, the yield strength and tensile strength are increased by 8.4% and 7.8%, and the electrical conductivity is increased by 24.4%. The increase in the strength of Hf-added alloy can be attributed to the synergistic effect of multiple strengthening mechanisms, including fine grain strengthening, twin strengthening, dislocation strengthening, precipitation strengthening and Σ3n (n = 1, 2, 3) grain boundary strengthening. Moreover, the Hf-P precipitates can be observed in the Hf-added alloy. According to the amount of Hf addition, these precipitates can manifest as the fine HfP2 phase and the coarse HfP phase. The formation of Hf-P precipitates contributes to the precipitation strengthening and the purification of Cu matrix, thus contributing to the improvement of strength and conductivity. © 2024, The Authors. All rights reserved.

关键词： Microstructure

Effects of CeO_(2)pre-calcined at different temperatures on the performance of Pt/CeO_(2)-C electrocatalyst for methanol oxidation reaction

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International Journal of Minerals,Metallurgy and materials 2021年第7期28卷 1224-1232页

作者： Guo-qing Li Pu-kang Wen Chen-qiang Gao Tian-yi Zhang Jun-yang Hu Yu-hao Zhang Shi-you Guan Qing-feng Li Bing Li School of Mechanical and Power Engineering East China University of Science and TechnologyShanghai 200237China School of Materials Science and Engineering East China University of Science and TechnologyShanghai 200237China Institute for Sustainable Energy College of SciencesShanghai UniversityShanghai 200237China Department of Energy Conversion and Storage Technical University of DenmarkLyngby 2800Denmark

Pt/CeO_(2)-C catalysts with CeO_(2)pre-calcined at 300-600 ℃were synthesized by combining hydrothermal calcination and wet *** effects of the pre-calcined CeO_(2)on the performance of Pt/CeO_(2)-C catalysts in methanol oxidation were *** Pt/CeO_(2)-C catalysts with pre-calcined CeO_(2)at 300-600 ℃showed an average particle size of 2.6-2.9 nm and exhibited better methanol elec-tro-oxidation catalytic activity than the commercial Pt/C *** specific,the Pt/CeO_(2)-C catalysts with pre-calcined CeO_(2)at 400 ℃dis-played the highest electrochemical surface area value of 68.14 m2·g−1 and If/Ib ratio(the ratio of the forward scanning peak current density(If)and the backward scanning peak current density(Ib))of 1.26,which are considerably larger than those(53.23 m2·g−1 and 0.79,respectively)of the commercial Pt/C catalyst,implying greatly enhanced CO tolerance.

关键词： direct methanol fuel cell platinum/cerium dioxide-carbon electrocatalyst methanol oxidation

Enhanced Performance of High-Temperature Proton Exchange Membranes Via Polyfluorene Cross-Linked Zwitterionic Liquid

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SSRN 2023年

作者： Xu, Fei Han, Yuyang Huang, Kai Li, Yanting Ding, Jianning Lin, Bencai School of Materials Science and Engineering Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering Changzhou University Jiangsu Changzhou213164 China School of Mechanical Engineering Yangzhou University Yangzhou225127 China

A satisfactory trade-off between physical/chemical stability and conductivity is crucial for high-temperature proton exchange membrane (HT-PEM) applications. Herein, a series of ether-free polyfluorenes cross-linked with zwitterionic liquids possessing both QA+ and –SO3− were prepared as crosslinked cHFTP–VIPSx via UV irradiation. Compared with non-crosslinked HFTP–TMA, crosslinked cHFTP–VIPSx exhibited enhanced conductivity, dimensional stability, oxidation stability, and phosphoric acid retention, which are attributed to the well-developed crosslinked structure and incorporated –SO3- groups. The as-fabricated H2/air single cell with a cross-linked cHFTP–VIPS30 achieved a higher peak power density (728 mW cm−2) than that of uncross-linked HFTP–TMA (287 mW cm−2) at 120 °C. Considering their enhanced performance, these cHFTP–VIPSx membranes cross-linked with zwitterionic liquid are promising HT-PEM materials for fuel cells. © 2023, The Authors. All rights reserved.

关键词： Proton exchange membrane fuel cells (PEMFC)

Machine Learning for Identifying Grain Boundaries in Scanning Electron Microscopy (SEM) Images of Nanoparticle Superlattices

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arXiv

arXiv 2025年

作者： Paruchuri, Aanish Thrasher, Carl Hart, A.J. Macfarlane, Robert Jayaraman, Arthi Science in Data Science Program University of Delaware NewarkDE19713 United States Department of Materials Science and Engineering Massachusetts Institute of Technology CambridgeMA02139 United States Department of Mechanical Engineering Massachusetts Institute of Technology CambridgeMA02139 United States Department of Chemical and Biomolecular Engineering University of Delaware 150 Academy St NewarkDE19713 United States Department of Materials Science and Engineering University of Delaware NewarkDE19713 United States Data Science Institute University of Delaware NewarkDE19713 United States

Nanoparticle superlattices consisting of ordered arrangements of nanoparticles exhibit unique optical, magnetic, and electronic properties arising from nanoparticle characteristics as well as their collective behaviors. Understanding how processing conditions influence the nanoscale arrangement and microstructure is critical for engineering materials with desired macroscopic properties. Microstructural features such as grain boundaries, lattice defects, and pores significantly affect these properties but are challenging to quantify using traditional manual analyses as they are labor-intensive and prone to errors. In this work, we present a machine learning workflow for automating grain segmentation in scanning electron microscopy (SEM) images of nanoparticle superlattices. This workflow integrates signal processing techniques, such as Radon transforms, with unsupervised learning methods like agglomerative hierarchical clustering to identify and segment grains without requiring manually annotated data. In the workflow we transform the raw pixel data into explainable numerical representation of superlattice orientations for clustering. Benchmarking results demonstrate the workflow's robustness against noisy images and edge cases, with a processing speed of four images per minute on standard computational hardware. This efficiency makes the workflow scalable to large datasets and makes it a valuable tool for integrating data-driven models into decision-making processes for material design and analysis. For example, one can use this workflow to quantify grain size distributions at varying processing conditions like temperature and pressure and using that knowledge adjust processing conditions to achieve desired superlattice orientations and grain sizes. © 2025, CC BY.

关键词： Grain boundaries

Effect of Co Content on Microstructure and mechanical Properties of Maraging Steel

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SSRN 2023年

作者： Wang, Ruian Wang, Yiran Gao, Yimin State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and Engineering Xi'an Jiaotong University Shanxi Xi’an710049 China

Effect of Co element on the microstructure and mechanical properties of maraging steel is studied and summarized. The microstructure and mechanical properties of five different compositions of maraging steels were characterized and tested in three heat treatment states, with the heat treatment schemes of homogenization treatment at 1300°C×10h, solution treatment at 800°C×2h, and aging treatment at 480°C×5h. It is found that in the three heat treatment states, the increase of Co content can make the pristine austenite grain size and martensite lath width reduction, in the aged state of the Co content can make the precipitation phase from ellipsoidal Mo-rich phase into needle-like Ni3(Mo, Ti) phase. Changes in the size, morphology and density of the precipitated phases, resulting in a more pronounced precipitation strengthening effect, the strength of the material increased significantly. © 2023, The Authors. All rights reserved.

关键词： Maraging steel

Layered metal chalcogenide of SnSe nanosheets integrated with 2D-hexagonal boron nitride for accurate and low-level detection of nitrofurazone

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Chemical engineering Journal 2023年 455卷

作者： Thirumalraj, Balamurugan Sriram, Balasubramanian Muthukutty, Balamurugan Zheng, Lianxi Wang, Sea-Fue Choe, Heeman Kwon, Kyungjung School of Materials Science & Engineering Kookmin University Seoul 02707 Korea Republic of Department of Energy & Mineral Resources Engineering Sejong University Seoul 05006 Korea Republic of Department of Materials and Mineral Resources Engineering National Taipei University of Technology Taipei 106 Taiwan Department of Materials Science and Chemical Engineering Hanyang University Gyeonggi-do Ansan15588 Korea Republic of Department of Mechanical Engineering Khalifa University of Science and Technology Abu Dhabi 127788 United Arab Emirates

Rising global demands for monitoring the health care and environmental system have increased the usage of antibodies as they are forced to deal with food products and environmental samples. Nitrofurazone (NF) is an important antibiotic that is widely used in clinical treatments, but its uncontrolled utilization and disposal wastage cause serious global issues into the ecosystem. Thus, a sensitive electrochemical method is developed for the real-time and low-level detection of NF. Layered metal chalcogenides of tin selenide (SnSe) integrated with hexagonal boron nitride (h-BN) are prepared as an electrode material for the detection of NF to take advantage of the unique structural and physiochemical properties of SnSe and h-BN. The physicochemical characteristics of SnSe/h-BN composite are determined with various spectral and analytical methods. The fabricated SnSe/h-BN electrode possesses excellent electrochemical activity for the detection of NF, with dual linear ranges of 0.001–12.12 µM and 15.2–342.2 µM, a low limit of detection of 0.34 nM, and a high sensitivity of 1.927 µA µM−1 cm−2. The superior performance could be attributed to the higher active surface area of the SnSe/h-BN composite and a synergistic effect between SnSe and h-BN that enhances the kinetics of the electron transfer over the electrode–electrolyte interface. The SnSe/h-BN electrode also achieves a satisfactory response level for the detection of NF in water and urine samples, thus indicating its feasibility for the rapid, low-level detection, and real-time analysis of NF. © 2022 Elsevier B.V.

关键词： Selenium compounds

Fuzzy Logic for Assessing the Health of a Corn Crop within Family Farming

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Fuzzy Logic for Assessing the Health of a Corn Crop within F...

Latin America Congress on Computational Intelligence (LA-CCI)

作者： Vanessa Mendonça Mikael Santos Daniel M. Muñoz Carlos Humberto Llanos Department of Computer Science Federal Institute of Brasilia Department of Mechanical Engineering Mechatronics Graduate Program Department of Agronomy Federal Institute of Brasilia Faculty of Gama Electronics Engineering Undergraduate Program University of Brasilia Brasilia DF Brazil

ISBN: (数字)9798350374575

ISBN: (纸本)9798350374582

Technological advancements are increasingly evident across various sectors, including automobiles, industry, and healthcare. In precision agriculture, significant progress has been made, with AgroTICs and Smart Agriculture gaining substantial traction in the market. However, a gap remains between cutting-edge technology and family farming, presenting a challenge from both social and applied research perspectives. However, there is still a gap between cutting-edge technology and family farming, which creates a challenge from a social and applied research point of view. In this context, this paper proposes a monitoring model based on Fuzzy Logic and sensor automation applied to estimate the health of a corn crop. The proposed Fuzzy inference system involves calculating an indicator of nutrients as well as the average color and area of corn plants. The nutrient indicator is automatically computed by an ESP32 microcontroller using sensor readings, while the average color and area inputs are manually entered via a mobile application. Additionally, the Fuzzy inference is integrated into the ESP32. The model underwent experimental validation on the health of the plantation, and the results were evaluated in four areas: one was designated for testing, and three were for validation. The model achieved an accuracy of 97.5% in Scenario 3, categorized as ’Very Favorable’, and an accuracy of 65% in Scenarios 2 and 4, categorized as ‘Unfavorable’. The implications of this research contribute to the advancement of AgroTICs among small producers, with the potential to enhance and automate the monitoring of their harvest production.

关键词： Fuzzy logic Accuracy Computational modeling Plantations Crops Production Color Nutrients Monitoring Fuzzy systems

Failure Analysis and Material Characterizations of a Ni-Based Superalloy Rotor Blade of a 25-Mw Industrial Gas Turbine

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SSRN 2024年

作者： Ajami Ghaleh Rashidi, Padina Ghorbani, Hassan Ezati, Meysam Yavari, Hadi Alizadeh, Mohammad School of Metallurgy and Materials Engineering Iran University of Science and Technology Tehran Iran School of Metallurgy and Materials Engineering College of Engineering University of Tehran P.O. Box 11155-4563 Tehran Iran School of Mechanical Engineering Sirjan University of Technology Kerman Iran School of Mechanical Engineering Sharif University of Technology P.O. Box 11155-9567 Tehran Iran School of Mechanical Engineering University of Tehran P.O. Box 11155-4563 Tehran Iran

This study examines the premature failure of hot-section-cooled blades in a 25-MW industrial gas turbine operating at elevated temperatures and high rotational stress. Upon conducting a thorough examination using scanning electron and optical microscopes, no significant changes were found in g¢ size and morphology, carbide degeneration, and grain boundary oxidation-widening as microstructural degradations. A detailed analysis of the fracture surface indicates that the primary mode of fracture was progressive fatigue, as evidenced by river lines and beach marks on the fractured surface. Furthermore, quantitative microscopic measurements reveal that the micro-scale inter-dendritic porosities, which are internal casting defects, exist in the sub-fracture surface. These defects would be candidate sites for crack initiation and propagation based on fatigue patterns. As a result of manufacturing deviations, the wall thickness on the top of the blade is out of tolerance, which can give rise to decrease structural integrity. Accordingly, initiation and propagation phenomena of high cycle fatigue crack were strongly influenced by the two abovementioned issues, hence, the premature failure occurred at this defected blade. Besides, finite element analysis was carried out to validate the above results. © 2024, The Authors. All rights reserved.

关键词： Porosity

ANALYSIS OF NITROGEN FLOW IN FOOD WASTE: A CASE STUDY OF THE UNIVERSITY RESTAURANT-UNB 32nd

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ANALYSIS OF NITROGEN FLOW IN FOOD WASTE: A CASE STUDY OF THE...

32nd European Biomass Conference and Exhibition, EUBCE 2024

作者： Ramos, Arthur Augusto Frasson De Brites, Eneida Campos Felipe Soares, Raquel Moraes Silveira, Edgar A. Contreras, Francisco University of Brasilia Department of Civil and Environmental Engineering DF Brasilia70910-900 Brazil University of Brasilia Graduate Program on Environmental Technology and Water Resources Department of Civil and Environmental Engineering DF Brasilia70910-900 Brazil Federal Institute of Education Science and Technology of Brasília Estrutural Campus DF Brasília71250-000 Brazil University of Brasília Mechanical Sciences Graduate Program Laboratory of Energy and Environment DF Brasilia70910-900 Brazil

With the projected global population reaching 9.7 billion by 2050, the production and consumption of food continue to escalate. Nitrogen is pivotal in this landscape due to its significance in living organisms and the environmental repercussions associated with nutrient-rich waste. Inappropriate disposal of such residues contributes to nitrogen release into the environment, impacting aquatic ecosystems and precipitating the generation of greenhouse gases. This study tackles the global challenge of effectively managing nitrogen in food waste by utilizing Material Flow Analysis (MFA) as a tool to comprehend this cycle. The analysis uncovered that vegetables, legumes, and fruits constitute the primary sources of waste generation, while meats, despite their lower mass, account for a substantial proportion of total nitrogen depletion. In the surveyed month of October 2023, 174,834 meals were served, resulting in an average food consumption N-footprint of 0.003 kg of nitrogen discarded per individual meal within the restaurant’s organic waste. These findings indicate that 65% of nitrogen is consumed in meal form, while 35% is discarded as organic solid waste. However, 53% of the nitrogen in the residues originates from food preparation processes, with food preparation responsible for over half of this figure. A deeper process analysis reveals that vegetables have low nitrogen concentrations, although they significantly contribute to waste at all stages. In contrast, meats and eggs, with higher nitrogen concentrations, emerge as noteworthy contributors to the overall nitrogen content in waste. Vegetables and meats contribute about 50% and 45% of the total nitrogen, respectively. These outcomes substantially enhance our comprehension of waste generation dynamics and nutrient utilization at the university restaurant, assisting with waste management, design of sustainable menus, reduction of food waste, and optimized resource utilization, contributing to sustainability and re

关键词： Effluent treatment