Ming-Chun Qi, Xiao-Song Yang, Chen Xia, San-Qiu Liu
The non-stationary Karpman–Washimi ponderomotive force and self-generated magnetic field in an unmagnetized system are investigated in the context of nonextensive distribution based on the kinetic theory. The ponderomotive force, magnetization, and radiation power are obtained as functions of the nonextensive parameter q, wave frequency, and wave number. It is shown that the presence of high-velocity electrons leads to an increase in temporal and spatial variation parts of ponderomotive force, magnetization, and radiation power. Furthermore, the results indicate that the self-generated magnetic field driven by the Karpman–Washimi ponderomotive force primarily manifests as small-scale and low-frequency magnetic field.
{"title":"Karpman–Washimi ponderomotive force and self-generated magnetic field in nonextensive plasmas","authors":"Ming-Chun Qi, Xiao-Song Yang, Chen Xia, San-Qiu Liu","doi":"10.1063/5.0228257","DOIUrl":"https://doi.org/10.1063/5.0228257","url":null,"abstract":"The non-stationary Karpman–Washimi ponderomotive force and self-generated magnetic field in an unmagnetized system are investigated in the context of nonextensive distribution based on the kinetic theory. The ponderomotive force, magnetization, and radiation power are obtained as functions of the nonextensive parameter q, wave frequency, and wave number. It is shown that the presence of high-velocity electrons leads to an increase in temporal and spatial variation parts of ponderomotive force, magnetization, and radiation power. Furthermore, the results indicate that the self-generated magnetic field driven by the Karpman–Washimi ponderomotive force primarily manifests as small-scale and low-frequency magnetic field.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"18 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wei Chen, Qi Chen, Jianmin Zhang, Yu Zheng, Ying Long
Inspired by the fabrication of the transition metal dichalcogenide nanoribbons with well-defined atomically precise edges, we study the stability, electronic structures, and magnetism of MTe2 (M = Cr, V, and Fe) monolayer nanoribbons. The calculations indicate that all three types of monolayers can form structurally stable zigzag (ZNR) and armchair (ANR) nanoribbons, which significantly alter the properties of the monolayer films, as shown in Table I. For the zigzag nanoribbons, CrTe2-ZNR transitions from a non-magnetic semiconductor to a ferrimagnetic metal. VTe2-ZNR transforms from a ferromagnetic semiconductor to a ferrimagnetic metal. FeTe2-ZNR mostly maintains the characteristics of the monolayer. For the armchair nanoribbons, CrTe2-ANR exhibits ferrimagnetism. The electrical conductivity is related to the width. CrTe2-ANR with narrow width is semiconducting, while wider ones are metallic. VTe2-ANR displays ferromagnetic or ferrimagnetic metallic behavior depending on the width. FeTe2-ANR with widths larger than 11 remains ferromagnetic metal, while with narrow widths are unstable. In addition, the magnetism of all MTe2 monolayer nanoribbons primarily originates from the 3d transition metal atoms. These findings are essential for applications of MTe2 nanoribbons-based low-dimensional spintronic devices.
{"title":"Electronic structures and magnetism of MTe2 (M = Cr, V, and Fe) monolayer nanoribbons","authors":"Wei Chen, Qi Chen, Jianmin Zhang, Yu Zheng, Ying Long","doi":"10.1063/5.0223768","DOIUrl":"https://doi.org/10.1063/5.0223768","url":null,"abstract":"Inspired by the fabrication of the transition metal dichalcogenide nanoribbons with well-defined atomically precise edges, we study the stability, electronic structures, and magnetism of MTe2 (M = Cr, V, and Fe) monolayer nanoribbons. The calculations indicate that all three types of monolayers can form structurally stable zigzag (ZNR) and armchair (ANR) nanoribbons, which significantly alter the properties of the monolayer films, as shown in Table I. For the zigzag nanoribbons, CrTe2-ZNR transitions from a non-magnetic semiconductor to a ferrimagnetic metal. VTe2-ZNR transforms from a ferromagnetic semiconductor to a ferrimagnetic metal. FeTe2-ZNR mostly maintains the characteristics of the monolayer. For the armchair nanoribbons, CrTe2-ANR exhibits ferrimagnetism. The electrical conductivity is related to the width. CrTe2-ANR with narrow width is semiconducting, while wider ones are metallic. VTe2-ANR displays ferromagnetic or ferrimagnetic metallic behavior depending on the width. FeTe2-ANR with widths larger than 11 remains ferromagnetic metal, while with narrow widths are unstable. In addition, the magnetism of all MTe2 monolayer nanoribbons primarily originates from the 3d transition metal atoms. These findings are essential for applications of MTe2 nanoribbons-based low-dimensional spintronic devices.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"5 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The incorporation of medical physics into the field of oncology has profoundly changed the ways in which cancer is diagnosed and treated. This article highlights the essential roles that medical physicists play in cancer care, demonstrating how principles from physics improve various aspects of oncology practices. Our analysis reveals that medical physics plays a fundamental role in optimizing various oncological procedures, thereby revolutionizing the management of cancer. Specifically, medical physicists are integral to critical areas such as radiation therapy planning, surgical navigation, and quality assurance, which collectively facilitate personalized and effective treatment strategies for patients. By working closely with healthcare professionals, medical physicists help ensure patients receive top-notch care while minimizing side effects associated with treatments. Their dedication to innovation and research is essential for improving both patient outcomes and quality of life throughout the cancer journey. The ongoing partnership between medical physicists and clinicians is instrumental in propelling advancements in oncology research and clinical practices, leveraging physics principles alongside state-of-the-art technologies to enhance cancer management. As medical physicists commit to excellence and patient-centered practices, they are at the forefront of transforming oncology care, promising improved hope and outcomes for those battling cancer. This collaborative effort ensures a bright future for cancer treatment, where the integration of physics not only optimizes therapeutic approaches but also fosters a comprehensive understanding of cancer care.
{"title":"Shaping the future of cancer treatment: The commitment of medical physicists","authors":"Marwan Al-Raeei","doi":"10.1063/5.0219314","DOIUrl":"https://doi.org/10.1063/5.0219314","url":null,"abstract":"The incorporation of medical physics into the field of oncology has profoundly changed the ways in which cancer is diagnosed and treated. This article highlights the essential roles that medical physicists play in cancer care, demonstrating how principles from physics improve various aspects of oncology practices. Our analysis reveals that medical physics plays a fundamental role in optimizing various oncological procedures, thereby revolutionizing the management of cancer. Specifically, medical physicists are integral to critical areas such as radiation therapy planning, surgical navigation, and quality assurance, which collectively facilitate personalized and effective treatment strategies for patients. By working closely with healthcare professionals, medical physicists help ensure patients receive top-notch care while minimizing side effects associated with treatments. Their dedication to innovation and research is essential for improving both patient outcomes and quality of life throughout the cancer journey. The ongoing partnership between medical physicists and clinicians is instrumental in propelling advancements in oncology research and clinical practices, leveraging physics principles alongside state-of-the-art technologies to enhance cancer management. As medical physicists commit to excellence and patient-centered practices, they are at the forefront of transforming oncology care, promising improved hope and outcomes for those battling cancer. This collaborative effort ensures a bright future for cancer treatment, where the integration of physics not only optimizes therapeutic approaches but also fosters a comprehensive understanding of cancer care.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"27 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Density functional theory-based characterization of crystalline tungsten oxide has been well established. Nonetheless, there remains a partial gap in theoretical studies concerning the electrochemical characterization of amorphous tungsten oxide. The electronic structure and diffusion kinetics of amorphous tungsten oxide require a systematic theoretical study. Therefore, we employed second-generation Car–Parrinello molecular dynamics simulations and the density functional theory with HSE06 exchange–correlation hybrid functional to investigate the electronic properties and lithium kinetics of amorphous tungsten oxide (α-WOx, x = 3, 2.5, 2) models. The precise electronic properties of these structures were computed using the HSE06 hybrid functions. The diffusion properties of lithium were determined in the range of 1 × 10−7 to 5 × 10−7 cm2/s by ab initio molecular dynamics. The computational findings provide a critical atomic-scale understanding and contribute to the development of tungsten oxide-based electrochromic devices for practical applications.
基于密度泛函理论的晶体氧化钨表征方法已经成熟。然而，关于无定形氧化钨电化学特性的理论研究仍存在部分空白。非晶态氧化钨的电子结构和扩散动力学需要系统的理论研究。因此，我们采用第二代 Car-Parrinello 分子动力学模拟和密度泛函理论与 HSE06 交换相关混合函数来研究无定形氧化钨 (α-WOx, x = 3, 2.5, 2) 模型的电子特性和锂动力学。使用 HSE06 混合函数计算了这些结构的精确电子特性。利用 ab initio 分子动力学确定了锂在 1 × 10-7 至 5 × 10-7 cm2/s 范围内的扩散特性。这些计算结果提供了关键的原子尺度理解，有助于开发基于氧化钨的电致变色器件的实际应用。
{"title":"Exploring the electronic structure and lithium diffusion kinetics of amorphous tungsten oxide","authors":"Chao Tang, Huachen Liu, Changlong Cai","doi":"10.1063/5.0229132","DOIUrl":"https://doi.org/10.1063/5.0229132","url":null,"abstract":"Density functional theory-based characterization of crystalline tungsten oxide has been well established. Nonetheless, there remains a partial gap in theoretical studies concerning the electrochemical characterization of amorphous tungsten oxide. The electronic structure and diffusion kinetics of amorphous tungsten oxide require a systematic theoretical study. Therefore, we employed second-generation Car–Parrinello molecular dynamics simulations and the density functional theory with HSE06 exchange–correlation hybrid functional to investigate the electronic properties and lithium kinetics of amorphous tungsten oxide (α-WOx, x = 3, 2.5, 2) models. The precise electronic properties of these structures were computed using the HSE06 hybrid functions. The diffusion properties of lithium were determined in the range of 1 × 10−7 to 5 × 10−7 cm2/s by ab initio molecular dynamics. The computational findings provide a critical atomic-scale understanding and contribute to the development of tungsten oxide-based electrochromic devices for practical applications.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"208 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The magnetospheric plasma (hot and thin) and the solar wind plasma (cold and dense) are separated by the Earth’s magnetopause, in which plasmas of both origins coexist. Different types of plasma diffusions are found due to this plasma mixing, and kinetic Alfvén solitary waves (KASWs) are one of them. In this work, a theoretical approach is taken to study the fundamental properties of heavy ion acoustic KASWs (HIAKASWs) in a magnetized plasma system whose constituents are nonextensive q-distributed two temperature electrons with dynamical heavy ions. The perturbations of the magnetized collisionless plasma system are investigated using the reductive perturbation technique to deduce the Korteweg–de Vries (K–DV) and modified K–DV (MK–DV) equations to determine the fundamental characteristics of small, but finite amplitude HIAKASWs. The presence of nonextensive electrons, magnetic field, obliquity angle (the angle between the external magnetic field and wave propagation), plasma particle number densities, and the temperature of various plasma species are observed to significantly alter the fundamental properties of HIAKASWs. The findings of our present study may be useful for comprehending the nonlinear wave properties in diverse interstellar plasma environments.
{"title":"Kinetic Alfvén solitary waves in astrophysical plasmas","authors":"M. M. Hasan, M. R. Hossen, A. A. Mamun","doi":"10.1063/5.0226568","DOIUrl":"https://doi.org/10.1063/5.0226568","url":null,"abstract":"The magnetospheric plasma (hot and thin) and the solar wind plasma (cold and dense) are separated by the Earth’s magnetopause, in which plasmas of both origins coexist. Different types of plasma diffusions are found due to this plasma mixing, and kinetic Alfvén solitary waves (KASWs) are one of them. In this work, a theoretical approach is taken to study the fundamental properties of heavy ion acoustic KASWs (HIAKASWs) in a magnetized plasma system whose constituents are nonextensive q-distributed two temperature electrons with dynamical heavy ions. The perturbations of the magnetized collisionless plasma system are investigated using the reductive perturbation technique to deduce the Korteweg–de Vries (K–DV) and modified K–DV (MK–DV) equations to determine the fundamental characteristics of small, but finite amplitude HIAKASWs. The presence of nonextensive electrons, magnetic field, obliquity angle (the angle between the external magnetic field and wave propagation), plasma particle number densities, and the temperature of various plasma species are observed to significantly alter the fundamental properties of HIAKASWs. The findings of our present study may be useful for comprehending the nonlinear wave properties in diverse interstellar plasma environments.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"42 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Phototransients are investigated for CuSbS2 films with varying the illumination energy. The generation and recombination of photocarriers, which are manifested as changes in the sheet conductivity of the films, take place almost instantaneously for excitation wavelengths of 970 and 633 nm. These rapid responses are, in contrast, absent for the illumination at wavelengths of 375 and 280 nm. In particular, roughly no photoconduction occurs in the case of 280 nm. The sheet conductivity develops thereby random two-level fluctuations following the illumination. Ultraviolet irradiation is thus suggested to generate crystalline defects, giving rise to the quenching of the instantaneous photoresponse caused by their trapping of the photocarriers. The photoresponse in simultaneous illumination at multiple wavelengths is dependent upon the relative intensities of the ultraviolet and visible/infrared components in a nonlinear fashion unless the photo-generated defects are overwhelmed by photocarriers.
{"title":"Evidence for the quenching of rapid photoresponse by defect generation in ultraviolet illumination of CuSbS2 films","authors":"Y. Takagaki","doi":"10.1063/5.0227670","DOIUrl":"https://doi.org/10.1063/5.0227670","url":null,"abstract":"Phototransients are investigated for CuSbS2 films with varying the illumination energy. The generation and recombination of photocarriers, which are manifested as changes in the sheet conductivity of the films, take place almost instantaneously for excitation wavelengths of 970 and 633 nm. These rapid responses are, in contrast, absent for the illumination at wavelengths of 375 and 280 nm. In particular, roughly no photoconduction occurs in the case of 280 nm. The sheet conductivity develops thereby random two-level fluctuations following the illumination. Ultraviolet irradiation is thus suggested to generate crystalline defects, giving rise to the quenching of the instantaneous photoresponse caused by their trapping of the photocarriers. The photoresponse in simultaneous illumination at multiple wavelengths is dependent upon the relative intensities of the ultraviolet and visible/infrared components in a nonlinear fashion unless the photo-generated defects are overwhelmed by photocarriers.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"15 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study examines resistive switching in a Cu/ZnO/ITO structure, uncovering an anomalous phenomenon that provides insights into the mechanisms of parallel conducting filaments in ZnO thin films. The current–voltage (I–V) characteristics exhibit a sharp switch at a positive threshold voltage around 2 V, transitioning from a high resistance pristine state to a low resistance state, interpreted as the formation of a Cu filament via electrochemical metallization. However, after this forming process, the device remains in the low resistance state and cannot reset to a high resistance state in either polarity of the applied voltage, suggesting the presence of a strong, unbreakable Cu filament after the forming process. What makes this phenomenon anomalous is the observed weak bipolar resistive switching in the cycles following the forming cycle, despite the presence of the Cu filament. The I–V characteristics of forward- and reverse-bias sweeps suggest that the weak bipolar resistive switching results from an additional filament formed in parallel with the existing unbreakable Cu filament. Using a parallel conducting filaments model, the resistivity of this additional filament is calculated to be ∼10−7–10−5 Ω m, indicating that this filament is likely generated by oxygen vacancies rather than metal atoms in the ZnO films.
这项研究考察了铜/氧化锌/氧化钛结构中的电阻开关，发现了一种异常现象，为了解氧化锌薄膜中平行导电丝的机制提供了启示。电流-电压（I-V）特性在 2 V 左右的正阈值电压时出现急剧切换，从高电阻原始状态过渡到低电阻状态，这被解释为通过电化学金属化形成了铜丝。然而，在这一形成过程之后，该器件仍处于低电阻状态，无论施加哪种极性的电压，都无法复位到高电阻状态，这表明在形成过程之后，存在着坚固、牢不可破的铜丝。使这一现象反常的是，尽管存在铜丝，但在成型周期之后的周期中观察到了微弱的双极电阻开关。正向和反向偏压扫描的 I-V 特性表明，微弱的双极电阻开关是由于与现有的不易破碎铜丝平行形成的附加铜丝造成的。利用平行导电丝模型，计算出这条附加丝的电阻率为 ∼10-7-10-5 Ω m，这表明这条附加丝很可能是由氧化锌薄膜中的氧空位而不是金属原子产生的。
{"title":"Parallel conducting filaments in resistive switching ZnO thin films","authors":"Tai-Min Liu, Zong-Wei Wu, Ting-An Chien, Pin-Qian Yang, Hua-Shu Hsu, Fang-Yuh Lo","doi":"10.1063/5.0232595","DOIUrl":"https://doi.org/10.1063/5.0232595","url":null,"abstract":"This study examines resistive switching in a Cu/ZnO/ITO structure, uncovering an anomalous phenomenon that provides insights into the mechanisms of parallel conducting filaments in ZnO thin films. The current–voltage (I–V) characteristics exhibit a sharp switch at a positive threshold voltage around 2 V, transitioning from a high resistance pristine state to a low resistance state, interpreted as the formation of a Cu filament via electrochemical metallization. However, after this forming process, the device remains in the low resistance state and cannot reset to a high resistance state in either polarity of the applied voltage, suggesting the presence of a strong, unbreakable Cu filament after the forming process. What makes this phenomenon anomalous is the observed weak bipolar resistive switching in the cycles following the forming cycle, despite the presence of the Cu filament. The I–V characteristics of forward- and reverse-bias sweeps suggest that the weak bipolar resistive switching results from an additional filament formed in parallel with the existing unbreakable Cu filament. Using a parallel conducting filaments model, the resistivity of this additional filament is calculated to be ∼10−7–10−5 Ω m, indicating that this filament is likely generated by oxygen vacancies rather than metal atoms in the ZnO films.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"116 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
There is a pronounced coupling vibration between the catenary and pantograph during operation for high-speed railways. In this paper, a pantograph–catenary coupling vibration model is constructed to investigate the vibration characteristics under various working conditions. Two different types of catenaries (simple and elastic chain types) are simulated and compared using the finite element method. The pantograph is simplified into a mass–spring–damping combination member, the contact and messenger wires are set to linear beam cells, and the dropper and stitch wire are set to truss cells. The results suggest that the vibration characteristics of the two types of catenaries and pantograph exhibit different trends. The maximum stresses of the messenger wire, dropper, and contact wire do not follow a monotonically increasing trend with the train speed. The maximum stress of the messenger wire under the simple chain type of catenary is higher when the initial contact force increases from 80 to 120 N. However, the maximum stress under the elastic chain type of catenary is higher when the initial contact force is 60 or 140 N. Except for the initial contact force of 140 N, the maximum stresses of the dropper and contact wire under the simple chain type of catenary are lower than those under the elastic chain type. This work provides a valuable reference for optimizing the design of pantograph–catenary systems.
{"title":"Numerical analysis of pantograph–catenary coupling vibration for high-speed railways","authors":"Like Pan, Peihuo Peng, Liming Chen, Fan He","doi":"10.1063/5.0219474","DOIUrl":"https://doi.org/10.1063/5.0219474","url":null,"abstract":"There is a pronounced coupling vibration between the catenary and pantograph during operation for high-speed railways. In this paper, a pantograph–catenary coupling vibration model is constructed to investigate the vibration characteristics under various working conditions. Two different types of catenaries (simple and elastic chain types) are simulated and compared using the finite element method. The pantograph is simplified into a mass–spring–damping combination member, the contact and messenger wires are set to linear beam cells, and the dropper and stitch wire are set to truss cells. The results suggest that the vibration characteristics of the two types of catenaries and pantograph exhibit different trends. The maximum stresses of the messenger wire, dropper, and contact wire do not follow a monotonically increasing trend with the train speed. The maximum stress of the messenger wire under the simple chain type of catenary is higher when the initial contact force increases from 80 to 120 N. However, the maximum stress under the elastic chain type of catenary is higher when the initial contact force is 60 or 140 N. Except for the initial contact force of 140 N, the maximum stresses of the dropper and contact wire under the simple chain type of catenary are lower than those under the elastic chain type. This work provides a valuable reference for optimizing the design of pantograph–catenary systems.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"208 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The significance of maintaining the surface stability of the In2O3 catalyst in the conversion of CO2 to methanol through hydrogenation cannot be overstated. To improve surface stability, doping with metal oxides is usually employed. To explore high-efficiency In2O3 based catalysts, density functional theory calculations were utilized to explore the effects of doping CuO, Co2O3, NiO, TiO2, HfO2, Nb2O3, Ta2O5, and CeO2 on the stability of the In2O3(110) surface. It was found that in a CO atmosphere, the crucial step in determining the creation of oxygen vacancies on the In2O3 plane occurred during the desorption of CO2 from the vacancy location. The results indicate that doping CuO, Co2O3, NiO, Nb2O3, Ta2O5, and CeO2 on the In2O3(110) surface promotes the reduction process through the reaction of CO with the O atoms on the surface, resulting in reduced surface stability. Conversely, the doping of Ti and Hf can raise the reaction energy barriers for CO reacting with the O atoms on the surface and enhance CO2 molecule adsorption on vacant sites, thereby suggesting the potential of TiO2 and HfO2 as effective modifiers to improve the efficiency and durability of the In2O3 catalyst. Furthermore, it is crucial to enhance its stability by modifying the density of the electron cloud or Fermi level of the In2O3 catalyst.
在通过氢化将二氧化碳转化为甲醇的过程中，保持 In2O3 催化剂表面稳定性的重要性怎么强调都不过分。为了提高表面稳定性，通常会采用掺杂金属氧化物的方法。为了探索基于 In2O3 的高效催化剂，研究人员利用密度泛函理论计算探讨了掺杂 CuO、Co2O3、NiO、TiO2、HfO2、Nb2O3、Ta2O5 和 CeO2 对 In2O3(110) 表面稳定性的影响。研究发现，在一氧化碳气氛中，决定 In2O3 表面产生氧空位的关键步骤发生在 CO2 从空位位置解吸的过程中。结果表明，在 In2O3（110）表面掺杂 CuO、Co2O3、NiO、Nb2O3、Ta2O5 和 CeO2 会通过 CO 与表面的 O 原子反应促进还原过程，导致表面稳定性降低。相反，Ti 和 Hf 的掺杂可以提高 CO 与表面 O 原子反应的反应能垒，增强 CO2 分子在空位上的吸附，从而表明 TiO2 和 HfO2 有可能成为有效的改性剂，提高 In2O3 催化剂的效率和耐用性。此外，通过改变 In2O3 催化剂的电子云密度或费米水平来提高其稳定性也至关重要。
{"title":"The effects of metal oxides doping on the surface stability of In2O3 for CO2 hydrogenation","authors":"Xingtang Xu, Yanwei Li, Guang Sun, Jianliang Cao, Yan Wang, Xulong Qin","doi":"10.1063/5.0224256","DOIUrl":"https://doi.org/10.1063/5.0224256","url":null,"abstract":"The significance of maintaining the surface stability of the In2O3 catalyst in the conversion of CO2 to methanol through hydrogenation cannot be overstated. To improve surface stability, doping with metal oxides is usually employed. To explore high-efficiency In2O3 based catalysts, density functional theory calculations were utilized to explore the effects of doping CuO, Co2O3, NiO, TiO2, HfO2, Nb2O3, Ta2O5, and CeO2 on the stability of the In2O3(110) surface. It was found that in a CO atmosphere, the crucial step in determining the creation of oxygen vacancies on the In2O3 plane occurred during the desorption of CO2 from the vacancy location. The results indicate that doping CuO, Co2O3, NiO, Nb2O3, Ta2O5, and CeO2 on the In2O3(110) surface promotes the reduction process through the reaction of CO with the O atoms on the surface, resulting in reduced surface stability. Conversely, the doping of Ti and Hf can raise the reaction energy barriers for CO reacting with the O atoms on the surface and enhance CO2 molecule adsorption on vacant sites, thereby suggesting the potential of TiO2 and HfO2 as effective modifiers to improve the efficiency and durability of the In2O3 catalyst. Furthermore, it is crucial to enhance its stability by modifying the density of the electron cloud or Fermi level of the In2O3 catalyst.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"29 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. Kavimani, P. M. Gopal, V. Sivamaran, Sameer Algburi, Debabrata Barik, Prabhu Paramasivam, Abdullah H. Alsabhan, Shamshad Alam
In this work, a newly discovered biomedical grade Magnesium–Lithium–Strontium (Mg–Li–Sr) alloy is machined using electrochemical machining technology. Two main output constraints employed on the research project to evaluate machinability are surface roughness (Ra) and material removal rate (MRR). Changing feed rate (FR), current, electrolyte concentration (EC), and voltage is required in order to carry out experimental experiments. The trials were designed using the Taguchi method. The ANOVA findings show that current is the most significant factor, after voltage as the most significant input parameter in regulating Ra and MRR. The ideal parameter configuration for the CRITIC-linked Deng’s similarity approach method was 5 V, 1 A of current, 0.4 mm/min of FR, and 20 g/l of EC. The final product was a 0.0323 mm/min MRR and a 2.61 μm surface roughness. Furthermore, the response variables are anticipated using the adaptive neuro-fuzzy Inference System, which finally results in predictions that are very similar to the experimental results.
{"title":"Experimental examination on electrochemical micro-machining of Mg–Li–Sr biomedical alloy: Application of ANOVA, Deng’s similarity, and ANFIS for effective modeling optimization","authors":"V. Kavimani, P. M. Gopal, V. Sivamaran, Sameer Algburi, Debabrata Barik, Prabhu Paramasivam, Abdullah H. Alsabhan, Shamshad Alam","doi":"10.1063/5.0220057","DOIUrl":"https://doi.org/10.1063/5.0220057","url":null,"abstract":"In this work, a newly discovered biomedical grade Magnesium–Lithium–Strontium (Mg–Li–Sr) alloy is machined using electrochemical machining technology. Two main output constraints employed on the research project to evaluate machinability are surface roughness (Ra) and material removal rate (MRR). Changing feed rate (FR), current, electrolyte concentration (EC), and voltage is required in order to carry out experimental experiments. The trials were designed using the Taguchi method. The ANOVA findings show that current is the most significant factor, after voltage as the most significant input parameter in regulating Ra and MRR. The ideal parameter configuration for the CRITIC-linked Deng’s similarity approach method was 5 V, 1 A of current, 0.4 mm/min of FR, and 20 g/l of EC. The final product was a 0.0323 mm/min MRR and a 2.61 μm surface roughness. Furthermore, the response variables are anticipated using the adaptive neuro-fuzzy Inference System, which finally results in predictions that are very similar to the experimental results.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"15 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：