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arXiv 2024年

作者： Liu, Chengchun Mo, Fanyang School of Materials Science and Engineering Peking University Beijing100871 China -Preferred Program Peking University Shenzhen Graduate School Shenzhen518055 China

Infrared (IR) spectroscopy is a pivotal technique in chemical research for elucidating molecular structures and dynamics through vibrational and rotational transitions. However, the intricate molecular fingerprints characterized by unique vibrational and rotational patterns present substantial analytical challenges. Here, we present a machine learning approach employing a Structural Attention Mechanism tailored to enhance the prediction and interpretation of infrared spectra, particularly for diazo compounds. Our model distinguishes itself by honing in on chemical information proximal to functional groups, thereby significantly bolstering the accuracy, robustness, and interpretability of spectral predictions. This method not only demystifies the correlations between infrared spectral features and molecular structures but also offers a scalable and efficient paradigm for dissecting complex molecular interactions. Copyright © 2024, The Authors. All rights reserved.

关键词： Molecular structure

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In-plane Wilson loop for measurement of quantized non-Abelian Berry flux

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Physical Review B 2024年第19期109卷 195149-195149页

作者： Alexander C. Tyner Shouvik Sur Qunfei Zhou Danilo Puggioni Pierre Darancet James M. Rondinelli Pallab Goswami Graduate Program in Applied Physics Northwestern University Evanston Illinois 60208 USA Department of Physics and Astronomy Northwestern University Evanston Illinois 60208 USA Materials Research Science and Engineering Center Northwestern University Evanston Illinois 60208 USA Center for Nanoscale Materials Argonne National Laboratory Argonne Illinois 60439 USA Department of Materials Science and Engineering Northwestern University Evanston Illinois 60208 USA Northwestern Argonne Institute for Science and Engineering Evanston Illinois 60208 USA

Band topology of anomalous quantum Hall insulators can be precisely addressed by computing the Chern numbers of constituent nondegenerate bands, describing the presence of quantized, Abelian Berry flux through the two-dimensional Brillouin zone. Can Berry flux be captured for the SU(2) Berry connection of two-fold degenerate bands in spinful materials preserving space-inversion (P) and time-reversal (T) symmetries without detailed knowledge of underlying basis? We address this question by investigating the correspondence between a non-Abelian generalization of Stokes' theorem and the manifestly gauge-invariant eigenvalues of Wilson loops computed along in-plane contours which preserve the underlying crystalline symmetry. The importance of this correspondence is elucidated by performing natural number resolved classification of ab initio band structures of three-dimensional, Dirac materials. Our work underscores how identification of quantized Berry flux, both Abelian and non-Abelian, offers a unified framework for addressing first-order and higher-order topology of insulators and semimetals.

关键词： Electronic structure of atoms & molecules First-principles calculations Topological insulators

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Evaluation of Single and Duplex Plasma Treatment Applied to Aisi 409 Stainless Steel

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SSRN 2024年

作者： do Monte e Silva, André Felipe Soares de Almeida, Larissa Solano Monteiro, Leandro Rossino, Luciana Sgarbi Nunes, Maelson Sousa Libório, Maxwell Santana de Carvalho Costa, Thércio Henrique Bandeira, Rafael Marinho de Sousa, Rômulo Ribeiro Magalhães Post-Graduate Materials Science and Engineering Program Federal University of Piauí PI Teresina Brazil Post-Graduate Program in Materials Science Federal University of São Carlos São Carlos Brazil Post-Graduate Program in Chemistry Federal University of Piauí PI Teresina Brazil School of Science and Technology Federal University of Rio Grande do Norte RN Natal Brazil Brazil Department of Mechanical Engineering Federal University of Piauí PI Teresina Brazil Brazil

The industrial landscape has witnessed a growing demand for components exhibiting superior performance and extended lifespan, especially in parts made of stainless steels like AISI 409 steel, widely used in automotive exhaust systems, heat exchangers, and lightweight structural components. This study investigates the enhancement of surface properties of AISI 409 stainless steel through cathodic cage plasma nitriding (CCPN) and cathodic cage plasma deposition (CCPD) processes, focusing on the novel implementation of duplex treatments. The research aims to improve the mechanical strength, wear resistance, and corrosion resistance of the steel by forming nitrides and vanadium nitride films on its surface. The duplex treatments, specifically N400D450 and N450D450, were found to significantly enhance the hardness of AISI 409 stainless steel, with the N450D450 sample achieving a maximum hardness of 1100 HV—a 461.22% increase compared to the untreated steel. This enhancement is attributed to the formation of a thick, uniform nitrided layer followed by a vanadium nitride film. The critical role of processing order was highlighted, with the sequence of nitriding followed by deposition proving more effective than the reverse. Corrosion resistance was markedly improved in the duplex-treated samples. The N450D450 sample exhibited an Ecorr of -198 mV and reduced jcorr values, indicating superior resistance to corrosive environments. These results underscore the synergistic effect of combining nitriding and vanadium deposition, which optimizes the formation of protective surface layers. Overall, this study demonstrates that duplex treatments significantly enhance the surface properties of AISI 409 stainless steel, offering the potential for extended component lifespan and reduced maintenance in industrial applications. The findings suggest that careful control of process parameters and treatment sequence is essential for achieving optimal results. © 2024, The Authors. All rights

关键词： Tribology

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Localization of a Crack in Moving Cylindrical Ferromagnetic Rods by Measuring the Fourier Coefficients of the Leakage Magnetic Flux

Localization of a Crack in Moving Cylindrical Ferromagnetic ...

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Magnetic Conference - Short Papers (INTERMAG Short Papers), IEEE International

作者： Kanta Shiku Masafumi Kuromizu Yuji Gotoh Takaaki Nara Graduate School of Information Science and Technology The University of Tokyo bunkyo-ku Japan Division of Materials Science and Production Engineering Graduate School of Engineering Oita University Oita Japan Intelligent Mechanical Systems Program Faculty of Science and Technology Oita University Oita Japan

ISBN: (数字)9798350362213

ISBN: (纸本)9798350362220

Electromagnetic nondestructive inspection for high-speed moving ferromagnetic materials is necessary for manufacturing efficiency. In this paper, we present a novel leakage magnetic flux (LMF) method to estimate the crack position in a moving cylindrical ferromagnetic rod. The method directly measures the first-order Fourier coefficients of the LMF moving with the crack by using only two coils with DC excitation. The location of a crack is estimated by the proposed method, as demonstrated for an S45C cylindrical rod.

关键词： Location awareness Coils Magnetic flux Inspection Ferromagnetic materials Manufacturing Electromagnetics

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Piezoelectric electrostatic superlattices in monolayer MoS2

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Physical Review materials 2024年第1期8卷 014002-014002页

作者： Ashwin Ramasubramaniam Doron Naveh Department of Mechanical and Industrial Engineering University of Massachusetts Amherst 01003 MA United States Materials Science and Engineering Graduate Program University of Massachusetts Amherst 01003 MA United States Faculty of Engineering Bar-Ilan University Ramat Gan 52900 Israel Institute for Nanotechnology and Advanced Materials Bar-Ilan University Ramat Gan 52900 Israel

Modulation of electronic properties of materials by electric fields is central to the operation of modern semiconductor devices, providing access to complex electronic behaviors and greater freedom in tuning the energy bands of materials. Here, we explore one-dimensional superlattices induced by a confining electrostatic potential in monolayer MoS2, a prototypical two-dimensional semiconductor. Using first-principles calculations, we show that periodic potentials applied to monolayer MoS2 induce electrostatic superlattices in which the response is dominated by structural distortions relative to purely electronic effects. These structural distortions reduce the intrinsic band gap of the monolayer substantially while also polarizing the monolayer through piezoelectric coupling, resulting in spatial separation of charge carriers as well as Stark shifts that produce dispersive minibands. Importantly, these minibands inherit the valley-selective magnetic properties of monolayer MoS2, enabling fine control over spin-valley coupling in MoS2 and similar transition-metal dichalcogenides.

关键词： Electronic structure Piezoelectricity Valley degrees of freedom

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engineering H2O2 Self-Supplying Platform for Xdynamic Therapies via Ru-Cu Peroxide Nanocarrier: Tumor Microenvironment-Mediated Synergistic Therapy

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ACS Applied materials and Interfaces 2024年第19期16卷 24172-24190页

作者： Dirersa, Worku Batu Kan, Tzu-Chun Chang, Jungshan Getachew, Girum Ochirbat, Sonjid Kizhepat, Shamsa Wibrianto, Aswandi Rasal, Akash Chen, Hung-An Ghule, Anil Vithal Chou, Tzung-Han Chang, Jia-Yaw Department of Chemical Engineering National Taiwan University of Science and Technology Taipei106335 Taiwan Graduate Institute of Medical Sciences College of Medicine Taipei Medical University Taipei11031 Taiwan International Master/Ph.D. Program in Medicine College of Medicine Taipei Medical University Taipei11031 Taiwan International Ph.D. Program for Cell Therapy and Regeneration Medicine College of Medicine Taipei Medical University Taipei11031 Taiwan Green Nanotechnology Laboratory Department of Chemistry Shivaji University Kolhapur416004 India Department of Chemical and Materials Engineering National Yunlin University of Science and Technology Yunlin64002 Taiwan

Of the most common, hypoxia, overexpressed glutathione (GSH), and insufficient H2O2 concentration in the tumor microenvironment (TME) are the main barriers to the advancment of reactive oxygen species (ROS) mediated Xdynamic therapies (X = photo, chemodynamic, chemo). Maximizing Fenton catalytic efficiency is crucial in chemodynamic therapy (CDT), yet endogenous H2O2 levels are not sufficient to attain better anticancer efficacy. Specifically, there is a need to amplify Fenton reactivity within tumors, leveraging the unique attributes of the TME. Herein, for the first time, we design RuxCu1-xO2-Ce6/CPT (RCpCCPT) anticancer nanoagent for TME-mediated synergistic therapy based on heterogeneous Ru-Cu peroxide nanodots (RuxCu1-xO2 NDs) and chlorine e6 (Ce6), loaded with ROS-responsive thioketal (TK) linked-camptothecin (CPT). The Ru-Cu peroxide NDs (RCp NDs, x = 0.50) possess the highest oxygen vacancy (OV) density, which grants them the potential to form massive Lewis’s acid sites for peroxide adsorption, while the dispersibility and targetability of the NDs were improved via surface modification using hyaluronic acid (HA). In TME, RCpCCPT degrades, releasing H2O2, Ru2+/3+, and Cu+/2+ ions, which cooperatively facilitate hydroxyl radical (•OH) formation and deactivate antioxidant GSH enzymes through a cocatalytic loop, resulting in excellent tumor therapeutic efficacy. Furthermore, when combined with laser treatment, RCpCCPT produces singlet oxygen (1O2) for PDT, which induces cell apoptosis at tumor sites. Following ROS generation, the TK linkage is disrupted, releasing up to 92% of the CPT within 48 h. In vitro investigations showed that laser-treated RCpCCPT caused 81.5% cell death from PDT/CDT and chemotherapy (CT). RCpCCPT in cancer cells produces red-blue emission in images of cells taking them in, which allows for fluorescence image-guided Xdynamic treatment. The overall results show that RCp NDs and RCpCCPT are more biocompatible and have excellent Xdynamic the

关键词： Oxidation

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The effects of growth environments on WS2 in electrocatalytic hydrogen evolution reaction

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Journal of Physics and Chemistry of Solids 2024年 185卷

作者： Chang, Yung-Huang Huang, Chien-Sheng Chen, Yuan-Tsung Chiang, Chia-Yu Bachelor Program in Industrial Technology National Yunlin University of Science and Technology Yunlin Taiwan Department of Electronic Engineering National Yunlin University of Science and Technology Yunlin Taiwan Graduate School of Materials Science National Yunlin University of Science and Technology Yunlin Taiwan

Transition metal dichalcogenides (TMDs) recently have attracted much attention because of their outstanding catalytic activity, low cost, and earth abundance in the hydrogen evolution reaction (HER). Among these TMDs, MoS2 and WS2 are recognized as promising HER electrocatalysts and have been explored to be one of the candidates for replacing precious metals. In this work, the electrocatalytic activity of WS2 grown in Ar-only, Ar + H2, and ambient environments were studied, where the WS2 was synthesized by thermolysis from (NH4)2WS4 precursor. Different surface morphologies are shown under the different growth atmospheres. The structures of pure WS2, WS2 and WO3 mixed, and almost WO3 were prepared in different growth atmospheres of Ar-only, Ar + H2, and ambient environment, respectively. All the materials prepared in these different environments exhibit high crystalline characteristic. Especially, the pure WS2 grown in an Ar-only environment presents the preferred (103) lattice plane. The pure WS2 performs the best H2 evolution efficiency, indicating that high crystallinity and preferred (103) lattice plane could be relative to the electrocatalytic activity. The studies provide fundamental insight for further design and preparation of electrocatalysts, useful in the development of clean energy. © 2023 Elsevier Ltd

关键词： Electrocatalysts

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Third-Order Optical Properties of Ag Nanocubes and Ag-Au Hollow Nanostructures Investigated by Femtosecond Z-Scan Measurements

SSRN

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SSRN 2024年

作者： Sousa, Claudevan A. Melo, Antonio F.A.A. Silva, Nefe J.B. Silva, Tânia Patrícia Silva E. Viana, Bartolomeu C. Santos, Francisco Eroni P. Garcia, Hans Department of Physics UFPI - Universidade Federal do Piauí PI Teresina64049-550 Brazil Materials Engineering Graduate Program Federal Institute of Education Science and Technology of Piauí Central Campus PI Teresina64000-040 Brazil Interdisciplinary Laboratory for Advanced Materials BioMatLab group Materials Science & Engineering Graduate Program UFPI - Universidade Federal do Piauí PI Teresina64049-550 Brazil

In this work, we reported experimental investigations on third-order optical properties of aqueous colloidal dispersions of silver nanocubes (Ag-NCs) and Ag-Au hollow nanostructures. The hollow bimetallic are nanoboxes, that were synthesized by galvanic substitution using silver nanocubes as templates, inserting silver with gold in molar ratios of 1.5 and 3.0 mL. This process adjusted tuning the Surface Plasmon Resonance (SPR) compared to the original Ag-NCs nanocubes. Femtosecond Z-scan measurements performed at 1040 nm, 350fs and laser intensities from 99.7 - 279 GW/cm2 shows negative nonlinear refraction for both nanocube and nanoboxes colloids, attributed to hot electron generation. Solvent effects are simultaneously suppressed of the nanostructures. On the other hand, the non-linear absorption observed for bimetallic nanoboxes shows the presence of saturated absorption (SA), but the Ag-NCs do not show a non-linear absorption signal. Therefore, our experimental results provide a reliable reference for the application of these bimetallic nanostructures as active media in nonlinear photonic devices. © 2024, The Authors. All rights reserved.

关键词： Surface plasmon resonance

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Optically-generated focused ultrasound for noninvasive brain stimulation with ultrahigh precision

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Light(science & Applications) 2022年第11期11卷 2817-2831页

作者： Yueming Li Ying Jiang Lu Lan Xiaowei Ge Ran Cheng Yuewei Zhan Guo Chen Linli Shi Runyu Wang Nan Zheng Chen Yang Ji-Xin Cheng Department of Mechanical Engineering Boston UniversityBostonMA 02215USA Graduate Program for Neuroscience Boston UniversityBostonMA 02215USA Department of Electrical and Computer Engineering Boston UniversityBostonMA 02215USA Department of Chemistry Boston UniversitBostonMA 02215USA Department of Biomedical Engineering Boston UniversityBostonMA 02215USA Division of Materials Science and Engineering Boston UniversityBostonMA 02215USA Department of Biological Engineering Massachusetts Institute of TechnologyCambridgeMA 02142USA

High precision neuromodulation is a powerful tool to decipher neurocircuits and treat neurological *** non-invasive neuromodulation methods offer limited precision at the milimeter ***,we report opticallygenerated focused ultrasound(OFUS)for non-invasive brain stimulation with ultrahigh *** is generated by a soft optoacoustic pad(SOAP)fabricated through embedding candle soot nanoparticles in a curved polydimethylsiloxane *** generates a transcranial ultrasound focus at 15 MHz with an ultrahigh lateral resolution of 83μm,which is two orders of magnitude smaller than that of conventional transcranial-focused ultrasound(tFUS).Here,we show effective OFUS neurostimulation in vitro with a single ultrasound *** demonstrate submillimeter transcranial stimulation of the mouse motor cortex in *** acoustic energy of 0.6 mJ/cm?,four orders of magnitude less than that of tFUS,is suffcient for successful OFUS *** offers new capabilities for neuroscience studies and disease treatments by delivering a focus with ultrahigh precision noninvasively.

关键词： SOAP stimulation precision

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Correlations between water quality and precipitation in areas with different levels of human occupation

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International Journal of Energy and Water Resources 2021年第1期5卷 25-31页

作者： Rodrigues, Lucas Augusto Pereira Radomski, Fernando Aparecido Dias Godoy, Rodrigo Felipe Bedim Trevisan, Elias Crisigiovanni, Enzo Luigi Department of Environment State University of Maringá Maringá-PR Brazil Graduate Program in Materials Science and Engineering Federal University of Paraná Curitiba-PR Brazil Graduate Program in Forest Sciences Unicentro Guarapuava-PR Brazil

Riverine water is largely used for human consumption and it is well known that its quality is correlated to many external factors. Because of that, this study evaluated linear correlations between precipitation and several water quality parameters using data collected from Antas’ river (Paraná, Brazil) at locations with different levels of human occupation aiming to identify water quality irregularities related to these important external factors, especially at a point surrounded by preserved vegetation. The statistical analyses were made using Pearson’s linear correlation coefficient (r) and the open source programming software, R. The results showed that precipitation has moderate to strong correlation with turbidity, true color, total coliforms and E. coli (0.99 ≥ r ≥ 0.44), and also has weak to moderate correlations with pH (− 0.39 ≥ r ≥ − 0.58) and biochemical oxygen demand (0.48 ≥ r ≥ 0.36), regardless of the level of human occupation nearby. The high correlations observed for E. coli and total coliforms in an area protected by native vegetation, probably due to adjacent rural activities, represents a novel and major finding. Dissolved oxygen and temperature showed no significant correlations with rainfall volume (0.26 ≥ r ≥ − 0.19). Since Brazilian law ensures that water quality parameters must be measured and considered in projects of water resources management, the proposed methodology seems to be promising for government policies applications, since it comprises only simple analyzes and a free software for simulations. © Islamic Azad University (IAU) 2021.

关键词： Hydrology R software Rainfall Spatial data Statistical analysis

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