Pub Date : 2024-08-11DOI: 10.1088/1402-4896/ad68d8
Mingyu Li, Lei Jia, Qingdong Miao, Wei Liu, Peng Zhao and Shufeng Yang
Through utilizing numerical simulation methods, the flow state of the molten pool during the vacuum self-consumption melting process of titanium alloy was analyzed. The influence of the stable arc cycle on the shape of the molten pool, dendrite arm spacing, surface quality, and shrinkage cavity was examined. The results showed that without an external magnetic field, the molten pool for smelting a Φ720 mm specification titanium alloy ingot is dominated by self-inductance magnetic force, leading to a downward flow in the central part of the melt. A mere 0.5 G stray magnetic field can result in Ekman pumping, causing an upward secondary flow in the core to counteract it. At an externally added magnetic field strength of 50 G, choosing a 10 s-20 s cycle can achieve a relatively stable double loop flow pattern. The shape of its molten pool, dendrite arm spacing, and contact ratio all reach optimal performance, thus verifying the possibility and feasibility of the double loop flow, and the macroscopic segregation of the simulated ingots essentially matches the experimental results, aiming to provide references for selecting parameters in actual production.
通过利用数值模拟方法，分析了钛合金真空自耗熔炼过程中熔池的流动状态。研究了稳定电弧周期对熔池形状、枝晶臂间距、表面质量和收缩腔的影响。结果表明，在没有外部磁场的情况下，熔炼Φ720 毫米规格钛合金铸锭的熔池由自感磁力主导，导致熔体中心部分向下流动。仅 0.5 G 的杂散磁场就会导致埃克曼抽气，从而在芯部产生向上的二次流动以抵消杂散磁场。在外部磁场强度为 50 G 的情况下，选择 10 s-20 s 的周期可以实现相对稳定的双环流动模式。其熔池形状、枝晶臂间距和接触比均达到最佳性能，从而验证了双回路流动的可能性和可行性，模拟铸锭的宏观偏析与实验结果基本吻合，旨在为实际生产中的参数选择提供参考。
{"title":"Numerical simulation of arc stabilizing cycle in vacuum arc remelting of titanium alloy","authors":"Mingyu Li, Lei Jia, Qingdong Miao, Wei Liu, Peng Zhao and Shufeng Yang","doi":"10.1088/1402-4896/ad68d8","DOIUrl":"https://doi.org/10.1088/1402-4896/ad68d8","url":null,"abstract":"Through utilizing numerical simulation methods, the flow state of the molten pool during the vacuum self-consumption melting process of titanium alloy was analyzed. The influence of the stable arc cycle on the shape of the molten pool, dendrite arm spacing, surface quality, and shrinkage cavity was examined. The results showed that without an external magnetic field, the molten pool for smelting a Φ720 mm specification titanium alloy ingot is dominated by self-inductance magnetic force, leading to a downward flow in the central part of the melt. A mere 0.5 G stray magnetic field can result in Ekman pumping, causing an upward secondary flow in the core to counteract it. At an externally added magnetic field strength of 50 G, choosing a 10 s-20 s cycle can achieve a relatively stable double loop flow pattern. The shape of its molten pool, dendrite arm spacing, and contact ratio all reach optimal performance, thus verifying the possibility and feasibility of the double loop flow, and the macroscopic segregation of the simulated ingots essentially matches the experimental results, aiming to provide references for selecting parameters in actual production.","PeriodicalId":20067,"journal":{"name":"Physica Scripta","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141969332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Pub Date : 2024-08-11DOI: 10.1088/1402-4896/ad69da
E Parasuraman, Aly R Seadawy and A Muniyappan
The investigation into modulational instability (MI) within the Kundu-Eckhaus (KE) equation, governing optical solitons, involves a thorough examination of the effects of self-phase modulation, cross-phase modulation, and intermodal dispersion. Special attention is given to understanding the influence of the four-wave mixing effect. The KE equation, which models birefringent fiber and includes terms related to intermodal dispersion, cross-phase modulation, and self-phase modulation, serves as the fundamental framework for this analytical study. Employing conventional linear stability analysis, the gain within the KE equation is determined. To shed light on the role of four-wave mixing in various scenarios, the gain spectrum is utilized as a tool to analyze the behavior of the KE equation under different conditions. This methodology seeks to provide insightful information about the intricate interactions that impact the modulational instability of solitonic pulses in an optical systems. After that, we have investigated the soliton solution by implementing the Jacobian elliptical function approach. Finally, our focus here is on linear stability analysis, which employs eigenvalue spectra to study solitons’ stability via direct numerical simulation.
对支配光孤子的昆杜-埃克豪斯（KE）方程中的调制不稳定性（MI）的研究，涉及对自相调制、跨相调制和模间色散效应的全面考察。其中特别注重理解四波混合效应的影响。KE 方程是双折射光纤的模型，包括与模间色散、跨相调制和自相调制相关的项，是这一分析研究的基本框架。通过传统的线性稳定性分析，确定了 KE 方程中的增益。为了阐明四波混合在各种情况下的作用，增益谱被用作分析 KE 方程在不同条件下的行为的工具。这种方法旨在提供有关影响光学系统中孤子脉冲调制不稳定性的复杂相互作用的深刻信息。之后，我们通过雅各布椭圆函数方法研究了孤子解。最后，我们将重点放在线性稳定性分析上，利用特征值谱通过直接数值模拟来研究孤子的稳定性。
{"title":"Stability and instability nature of solitons in an optical fiber with four wave mixing effect","authors":"E Parasuraman, Aly R Seadawy and A Muniyappan","doi":"10.1088/1402-4896/ad69da","DOIUrl":"https://doi.org/10.1088/1402-4896/ad69da","url":null,"abstract":"The investigation into modulational instability (MI) within the Kundu-Eckhaus (KE) equation, governing optical solitons, involves a thorough examination of the effects of self-phase modulation, cross-phase modulation, and intermodal dispersion. Special attention is given to understanding the influence of the four-wave mixing effect. The KE equation, which models birefringent fiber and includes terms related to intermodal dispersion, cross-phase modulation, and self-phase modulation, serves as the fundamental framework for this analytical study. Employing conventional linear stability analysis, the gain within the KE equation is determined. To shed light on the role of four-wave mixing in various scenarios, the gain spectrum is utilized as a tool to analyze the behavior of the KE equation under different conditions. This methodology seeks to provide insightful information about the intricate interactions that impact the modulational instability of solitonic pulses in an optical systems. After that, we have investigated the soliton solution by implementing the Jacobian elliptical function approach. Finally, our focus here is on linear stability analysis, which employs eigenvalue spectra to study solitons’ stability via direct numerical simulation.","PeriodicalId":20067,"journal":{"name":"Physica Scripta","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141969340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 investigation focuses on the development and characterization of sustainable composite materials for insulation and structural components in the automotive and shipbuilding industries, by incorporating date palm Rachis fibers into an epoxy matrix. Thus, we evaluated the effect of the weight ratio (ranging from 0 to 15 wt%) of Rachis fibers (0.315 mm) on the mechanical, physical, surface morphology, thermal properties, and water absorption. It turns out according to the study that, the XRD pattern revealed the amorphous nature of the composite. This new material can be used as composite material itself or as a skin of a sandwich composite material. The Epoxy-Rachis (ER) composite materials exhibited a low thermal conductivity of 0.21 W/ (m.K) and a low thermal diffusivity of 0.17 mm2 s−1 presenting high thermal insulation and construction properties. The SEM images showed that increasing Rachis fiber concentration produces a heterogeneous bio-composite material. The resulting composition showcases ductile fracture behavior with a flexural modulus (Ef) of 3.21 GPa and a bending strength (σ) of 9.28 MPa. These attributes underline the suitability of this composite for applications requiring efficient thermal insulation and robust construction properties, while simultaneously contributing to environmental sustainability and environmental benefits.
{"title":"Sustainable composite materials with date palm rachis fibers for enhanced insulation and structural integrity","authors":"Maroua Ferhat, Hocine Djemai, Elhachmi Guettaf Temam, Adnane Labed, Lemya Lahag and Youcef Sid Amer","doi":"10.1088/1402-4896/ad69e2","DOIUrl":"https://doi.org/10.1088/1402-4896/ad69e2","url":null,"abstract":"This investigation focuses on the development and characterization of sustainable composite materials for insulation and structural components in the automotive and shipbuilding industries, by incorporating date palm Rachis fibers into an epoxy matrix. Thus, we evaluated the effect of the weight ratio (ranging from 0 to 15 wt%) of Rachis fibers (0.315 mm) on the mechanical, physical, surface morphology, thermal properties, and water absorption. It turns out according to the study that, the XRD pattern revealed the amorphous nature of the composite. This new material can be used as composite material itself or as a skin of a sandwich composite material. The Epoxy-Rachis (ER) composite materials exhibited a low thermal conductivity of 0.21 W/ (m.K) and a low thermal diffusivity of 0.17 mm2 s−1 presenting high thermal insulation and construction properties. The SEM images showed that increasing Rachis fiber concentration produces a heterogeneous bio-composite material. The resulting composition showcases ductile fracture behavior with a flexural modulus (Ef) of 3.21 GPa and a bending strength (σ) of 9.28 MPa. These attributes underline the suitability of this composite for applications requiring efficient thermal insulation and robust construction properties, while simultaneously contributing to environmental sustainability and environmental benefits.","PeriodicalId":20067,"journal":{"name":"Physica Scripta","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141969388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Pub Date : 2024-08-08DOI: 10.1088/1402-4896/ad69e6
Md Sagib, Bijan Krishna Saha, Sanjaya K Mohanty and Md Sazedur Rahman
This paper introduces novel traveling wave solutions for the (1+1)-dimensional nonlinear telegraph equation (NLTE) and the (2+1)-dimensional nonlinear electrical transmission line equation (NETLE). These equations are pivotal in the transmission and propagation of electrical signals, with applications in telegraph lines, digital image processing, telecommunications, and network engineering. We applied the improved tanh technique combined with the Riccati equation to derive new solutions, showcasing various solitary wave patterns through 3D surface and 2D contour plots. These results provide more comprehensive solutions than previous studies and offer practical applications in communication systems utilizing solitons for data transmission. The proposed method demonstrates an efficient calculation process, aiding researchers in analyzing nonlinear partial differential equations in applied mathematics, physics, and engineering
{"title":"Diverse soliton solutions to the nonlinear partial differential equations related to electrical transmission line","authors":"Md Sagib, Bijan Krishna Saha, Sanjaya K Mohanty and Md Sazedur Rahman","doi":"10.1088/1402-4896/ad69e6","DOIUrl":"https://doi.org/10.1088/1402-4896/ad69e6","url":null,"abstract":"This paper introduces novel traveling wave solutions for the (1+1)-dimensional nonlinear telegraph equation (NLTE) and the (2+1)-dimensional nonlinear electrical transmission line equation (NETLE). These equations are pivotal in the transmission and propagation of electrical signals, with applications in telegraph lines, digital image processing, telecommunications, and network engineering. We applied the improved tanh technique combined with the Riccati equation to derive new solutions, showcasing various solitary wave patterns through 3D surface and 2D contour plots. These results provide more comprehensive solutions than previous studies and offer practical applications in communication systems utilizing solitons for data transmission. The proposed method demonstrates an efficient calculation process, aiding researchers in analyzing nonlinear partial differential equations in applied mathematics, physics, and engineering","PeriodicalId":20067,"journal":{"name":"Physica Scripta","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141969389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Pub Date : 2024-08-08DOI: 10.1088/1402-4896/ad69de
Manjunath M N, Vivek Singh, Ajay Kumar Dwivedi and Stuti Pandey
A novel dual Port C-Shape MIMO broadband printed antenna with wide axial ratio bandwidth (ARBW) is modelled and built for Ku band Applications. The unit cell of the proposed antenna has a compact size of 25 × 26 × 0.8 mm3 engraved on RT duriod 5880 material (εr = 2.2, thickness of 0.8 mm). The proposed model consists of C shaped radiator, plus symbol structure and a modified ground plane. The machine learning concept is used to investigate the dimensional dependency of the plus sign on the CP behaviour. The suggested antenna shows impedance bandwidth (−10 dB) and 3-dB ARBW of 6 GHz (12 GHz to 18 GHz) which is covering the whole Ku band. The diversity performance parameters and antenna parametric investigation is also carried out to justify the MIMO identity of the proposed design. The simulated and measured counterparts are found in harmony. The strength of the proposed antenna is its planar structure, wide ARBW, polarization diversity, and wide operating Ku bandwidth.
为 Ku 波段应用模拟并制作了一种具有宽轴比带宽（ARBW）的新型双端口 C 形 MIMO 宽带印刷天线。拟议天线的单元尺寸为 25 × 26 × 0.8 mm3，刻在 RT duriod 5880 材料上（εr = 2.2，厚度为 0.8 mm）。提出的模型由 C 形散热器、符号结构和改进的接地平面组成。机器学习概念用于研究加号对 CP 行为的尺寸依赖性。该天线的阻抗带宽（-10 dB）和 3-dB ARBW 为 6 GHz（12 GHz 至 18 GHz），覆盖整个 Ku 波段。此外，还进行了分集性能参数和天线参数调查，以证明拟议设计的 MIMO 特性。模拟和测量结果一致。拟议天线的优势在于其平面结构、宽 ARBW、极化分集和宽工作 Ku 带宽。
{"title":"Machine learning validated compact circularly polarized dual port-MIMO antenna with polarization diversity for ku-band applications","authors":"Manjunath M N, Vivek Singh, Ajay Kumar Dwivedi and Stuti Pandey","doi":"10.1088/1402-4896/ad69de","DOIUrl":"https://doi.org/10.1088/1402-4896/ad69de","url":null,"abstract":"A novel dual Port C-Shape MIMO broadband printed antenna with wide axial ratio bandwidth (ARBW) is modelled and built for Ku band Applications. The unit cell of the proposed antenna has a compact size of 25 × 26 × 0.8 mm3 engraved on RT duriod 5880 material (εr = 2.2, thickness of 0.8 mm). The proposed model consists of C shaped radiator, plus symbol structure and a modified ground plane. The machine learning concept is used to investigate the dimensional dependency of the plus sign on the CP behaviour. The suggested antenna shows impedance bandwidth (−10 dB) and 3-dB ARBW of 6 GHz (12 GHz to 18 GHz) which is covering the whole Ku band. The diversity performance parameters and antenna parametric investigation is also carried out to justify the MIMO identity of the proposed design. The simulated and measured counterparts are found in harmony. The strength of the proposed antenna is its planar structure, wide ARBW, polarization diversity, and wide operating Ku bandwidth.","PeriodicalId":20067,"journal":{"name":"Physica Scripta","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141969386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Pub Date : 2024-08-08DOI: 10.1088/1402-4896/ad69d6
Wahiba Tlili, Sarra Bouazizi, Bassem Kadri, Amal Bouich, Rabeb Issaoui, Alia Ghrissi, Mosbah Amlouk and Ahmed Omri
Inverted solar cells have attracted significant attention because they have low hysteresis and are resistant to environmental variables, such as oxygen and humidity, making them more stable and long-lasting. Herein, we investigate the performance optimisation of an inverted design based on MAPbI3-xClx with the structure ITO/PTAA/MAPbI3-xClx/PC60BM/BCP/Ag by utilising SCAPS-1D, a simulation tool. Accordingly, a substantial improvement in efficiency can be achieved by optimising several factors linked to each layer’s performance in a perovskite solar cell (PSC). Total defect density, work function, thickness, and electron affinity have a significant impact on the photovoltaic response. Specifically, the impact of optimisation of the charge transport layers and the perovskite layer on the device’s performance parameters was discussed, resulting in a milestone within a remarkable increase in PCE of 21.59%, whereas the original structure’s efficiency was 6.9%. Additionally, it has been shown that aluminium can substitute silver in the top electrode of a solar cell without affecting its efficiency, allowing the development of cost-effective solar cells. The present study provides an insight in the creation of a highly stable low-cost and higher-efficiency perovskite solar cell.
{"title":"Boosting the efficiency of an inverted structure halide perovskite solar cell: a numerical investigation","authors":"Wahiba Tlili, Sarra Bouazizi, Bassem Kadri, Amal Bouich, Rabeb Issaoui, Alia Ghrissi, Mosbah Amlouk and Ahmed Omri","doi":"10.1088/1402-4896/ad69d6","DOIUrl":"https://doi.org/10.1088/1402-4896/ad69d6","url":null,"abstract":"Inverted solar cells have attracted significant attention because they have low hysteresis and are resistant to environmental variables, such as oxygen and humidity, making them more stable and long-lasting. Herein, we investigate the performance optimisation of an inverted design based on MAPbI3-xClx with the structure ITO/PTAA/MAPbI3-xClx/PC60BM/BCP/Ag by utilising SCAPS-1D, a simulation tool. Accordingly, a substantial improvement in efficiency can be achieved by optimising several factors linked to each layer’s performance in a perovskite solar cell (PSC). Total defect density, work function, thickness, and electron affinity have a significant impact on the photovoltaic response. Specifically, the impact of optimisation of the charge transport layers and the perovskite layer on the device’s performance parameters was discussed, resulting in a milestone within a remarkable increase in PCE of 21.59%, whereas the original structure’s efficiency was 6.9%. Additionally, it has been shown that aluminium can substitute silver in the top electrode of a solar cell without affecting its efficiency, allowing the development of cost-effective solar cells. The present study provides an insight in the creation of a highly stable low-cost and higher-efficiency perovskite solar cell.","PeriodicalId":20067,"journal":{"name":"Physica Scripta","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141969384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Pub Date : 2024-08-08DOI: 10.1088/1402-4896/ad69e5
Lihuan Xie, Xin Luo, Zhijun Zhou and Yinjian Zhao
The lack of understanding of the azimuthal instability and the resulting electron anomalous transport limits further improvement of Hall thrusters. Compared to theoretical and experimental approaches, the numerical particle-in-cell (PIC) simulation is a suitable and powerful tool, which has been widely applied to investigate the azimuthal instability, and great progress has been made in the past decades. However, PIC simulations are intrinsically computationally expensive, and it is realized that the Hall thruster azimuthal instability has a three dimensional nature. Therefore, massive 3D PIC simulation must be carried out to completely reveal the mechanism of the instability. In this paper, the effect of plasma initialization on 3D PIC simulation of Hall thruster azimuthal instability is studied as a starting point. It is found that by initializing with ion density and velocity fitting functions to the steady-state simulation results, a faster convergence can be obtained and the computational time can be reduced by about 1.5 times. Typical fitting functions of ion density, drifting velocity, and temperature are given, and the influence of different initialization profiles is presented.
{"title":"Effect of plasma initialization on 3D PIC simulation of Hall thruster azimuthal instability","authors":"Lihuan Xie, Xin Luo, Zhijun Zhou and Yinjian Zhao","doi":"10.1088/1402-4896/ad69e5","DOIUrl":"https://doi.org/10.1088/1402-4896/ad69e5","url":null,"abstract":"The lack of understanding of the azimuthal instability and the resulting electron anomalous transport limits further improvement of Hall thrusters. Compared to theoretical and experimental approaches, the numerical particle-in-cell (PIC) simulation is a suitable and powerful tool, which has been widely applied to investigate the azimuthal instability, and great progress has been made in the past decades. However, PIC simulations are intrinsically computationally expensive, and it is realized that the Hall thruster azimuthal instability has a three dimensional nature. Therefore, massive 3D PIC simulation must be carried out to completely reveal the mechanism of the instability. In this paper, the effect of plasma initialization on 3D PIC simulation of Hall thruster azimuthal instability is studied as a starting point. It is found that by initializing with ion density and velocity fitting functions to the steady-state simulation results, a faster convergence can be obtained and the computational time can be reduced by about 1.5 times. Typical fitting functions of ion density, drifting velocity, and temperature are given, and the influence of different initialization profiles is presented.","PeriodicalId":20067,"journal":{"name":"Physica Scripta","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141969472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Pub Date : 2024-08-08DOI: 10.1088/1402-4896/ad69cd
Jince Zhang, Xiaochen Qi, Di Liu, Yixiang Hu, Yukun Chen, Ziyue Zhou, Taiyu Jin, Dawei Fang and Jun Wang
As representative non-toxic cadmium-free quantum dots (QDs), ZnS QDs with high quantum efficiency, super stability and excellent biocompatibility had attracted wide attention in the fields of photocatalysis, solar cells and biomedicine. In this study, hydrodynamic cavitation (HC) technology was applied to the preparation of ZnS QDs. By adjusting HC device parameters, water soluble ZnS QDs with small particle size, narrow particle size distribution range, high absorbance, high luminous efficiency and high quantum yield were prepared. The morphology, size distribution, element composition and optical properties of ZnS QDs were studied by various characterization methods. ZnS QDs with average particle size of 1.48 nm, fluorescence quantum yield of 34.07% and Stokes shift of 112 nm were obtained. In addition, the mechanism of preparation of ZnS QDs by using HC method was also studied. It is hoped that this HC technology can provide a new idea for large-scale preparation of ZnS QDs with excellent properties.
作为无毒无镉量子点（QDs）的代表，ZnS QDs具有高量子效率、超强稳定性和良好的生物相容性，在光催化、太阳能电池和生物医药领域受到广泛关注。本研究将流体动力空化（HC）技术应用于制备 ZnS QDs。通过调整 HC 设备参数，制备出了粒径小、粒径分布范围窄、高吸光度、高光效和高量子产率的水溶性 ZnS QDs。通过各种表征方法研究了 ZnS QDs 的形貌、粒度分布、元素组成和光学特性。得到的 ZnS QDs 平均粒径为 1.48 nm，荧光量子产率为 34.07%，斯托克斯位移为 112 nm。此外，还研究了利用 HC 方法制备 ZnS QDs 的机理。希望这种 HC 技术能为大规模制备具有优异性能的 ZnS QDs 提供新的思路。
{"title":"Synthesis of uniform sized ZnS quantum dots using hydrodynamic cavitation and their characterization","authors":"Jince Zhang, Xiaochen Qi, Di Liu, Yixiang Hu, Yukun Chen, Ziyue Zhou, Taiyu Jin, Dawei Fang and Jun Wang","doi":"10.1088/1402-4896/ad69cd","DOIUrl":"https://doi.org/10.1088/1402-4896/ad69cd","url":null,"abstract":"As representative non-toxic cadmium-free quantum dots (QDs), ZnS QDs with high quantum efficiency, super stability and excellent biocompatibility had attracted wide attention in the fields of photocatalysis, solar cells and biomedicine. In this study, hydrodynamic cavitation (HC) technology was applied to the preparation of ZnS QDs. By adjusting HC device parameters, water soluble ZnS QDs with small particle size, narrow particle size distribution range, high absorbance, high luminous efficiency and high quantum yield were prepared. The morphology, size distribution, element composition and optical properties of ZnS QDs were studied by various characterization methods. ZnS QDs with average particle size of 1.48 nm, fluorescence quantum yield of 34.07% and Stokes shift of 112 nm were obtained. In addition, the mechanism of preparation of ZnS QDs by using HC method was also studied. It is hoped that this HC technology can provide a new idea for large-scale preparation of ZnS QDs with excellent properties.","PeriodicalId":20067,"journal":{"name":"Physica Scripta","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141969382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Pub Date : 2024-08-08DOI: 10.1088/1402-4896/ad69cf
Guoqing Wang, Ben Gao, Gai Zhao, Haoyu Shi, Shuntao Fang and Yuzhen Liu
In this study, we constructed a dataset of elastic modulus and ultimate stress for copper material enhanced by Transition Metal Dichalcogenides (TMDs) through Molecular Dynamics (MD) simulations. Subsequently, leveraging chemical insights, we selected appropriate descriptors and established machine learning prediction models for elastic modulus and ultimate stress, respectively. Finally, the performance of the machine learning models was evaluated using a test set. The results demonstrate excellent performance of the machine learning models in predicting material properties. This work presents a novel approach for efficient material screening, demonstrating the synergy between MD simulations and machine learning in advancing materials research and intelligent material selection platforms.
{"title":"Machine learning accelerated the prediction of mechanical properties of copper modified by TMDs based on molecular dynamics simulation","authors":"Guoqing Wang, Ben Gao, Gai Zhao, Haoyu Shi, Shuntao Fang and Yuzhen Liu","doi":"10.1088/1402-4896/ad69cf","DOIUrl":"https://doi.org/10.1088/1402-4896/ad69cf","url":null,"abstract":"In this study, we constructed a dataset of elastic modulus and ultimate stress for copper material enhanced by Transition Metal Dichalcogenides (TMDs) through Molecular Dynamics (MD) simulations. Subsequently, leveraging chemical insights, we selected appropriate descriptors and established machine learning prediction models for elastic modulus and ultimate stress, respectively. Finally, the performance of the machine learning models was evaluated using a test set. The results demonstrate excellent performance of the machine learning models in predicting material properties. This work presents a novel approach for efficient material screening, demonstrating the synergy between MD simulations and machine learning in advancing materials research and intelligent material selection platforms.","PeriodicalId":20067,"journal":{"name":"Physica Scripta","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141969383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Pub Date : 2024-08-08DOI: 10.1088/1402-4896/ad69e1
Arjo Dasgupta and Indra Dasgupta
The topological phase transition in the Qi-Wu-Zhang model is studied using a real-space approach. An effective Hamiltonian for the topologically protected edge-modes in a finite-size system is developed. The topological phase transition is understood in terms of a global perturbation to the system which lifts the degeneracy of the edge-modes. The effective Hamiltonian method is also applied to a one-dimensional system with spatially varying hopping strengths to understand the impact of disorder on the edge-modes.
{"title":"Gapless edge-modes and topology in the Qi-Wu-Zhang model: a real-space analysis","authors":"Arjo Dasgupta and Indra Dasgupta","doi":"10.1088/1402-4896/ad69e1","DOIUrl":"https://doi.org/10.1088/1402-4896/ad69e1","url":null,"abstract":"The topological phase transition in the Qi-Wu-Zhang model is studied using a real-space approach. An effective Hamiltonian for the topologically protected edge-modes in a finite-size system is developed. The topological phase transition is understood in terms of a global perturbation to the system which lifts the degeneracy of the edge-modes. The effective Hamiltonian method is also applied to a one-dimensional system with spatially varying hopping strengths to understand the impact of disorder on the edge-modes.","PeriodicalId":20067,"journal":{"name":"Physica Scripta","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141969387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
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