Science China Physics, Mechanics & Astronomy最新文献_第6页

Aligning nano-scale crystals in bulk materials 在块状材料中排列纳米级晶体

IF 6.4 1区物理与天体物理

Science China Physics, Mechanics & Astronomy Pub Date : 2025-02-20 DOI: 10.1007/s11433-024-2572-5

Xiangyi Zhang, Yingxin Hua, Xiaohong Li

{"title":"Aligning nano-scale crystals in bulk materials","authors":"Xiangyi Zhang, Yingxin Hua, Xiaohong Li","doi":"10.1007/s11433-024-2572-5","DOIUrl":"10.1007/s11433-024-2572-5","url":null,"abstract":"<div><p>Crystal orientation determines various material performances including magnetic, electrical, and mechanical properties. However, achieving the alignment of nano-grains along a specific crystallographic orientation in bulk materials remains a formidable challenge. Departing from conventional approaches using polycrystalline materials, we report a strategy to overcome this challenge by deliberately introducing strain-energy anisotropy to select oriented nucleation/growth of crystals in amorphous materials. To demonstrate its efficacy, we employed ferromagnetic materials as a proof of concept. Using our approach, a range of previously inaccessible bulk ferromagnetic nanomaterials with strong <i>c</i>-axis orientation have been created. The resulting bulk oriented nano-grained magnets exhibit a high energy density, 168 kJ m<sup>−3</sup> for SmCo<sub>7</sub> and 235.2 kJ m<sup>−3</sup> for PrCo<sub>5</sub> ferromagnets, greatly surpassing that of their state-of-the-art counterparts with 23%–62% enhancement. Our strategy is general and applicable to other material systems, including thermoelectric, piezoelectric, and ferroelectric materials, to achieve the desired oriented nano-grains for technological applications.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"68 4","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143466045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}

引用次数: 0

A fully mesh-independent non-linear topology optimization framework based on neural representations: Quasi-static problem 基于神经网络表征的完全网格无关非线性拓扑优化框架：准静态问题

IF 6.4 1区物理与天体物理

Science China Physics, Mechanics & Astronomy Pub Date : 2025-02-20 DOI: 10.1007/s11433-024-2576-7

Zeyu Zhang, Yu Li, Weien Zhou, Wen Yao

{"title":"A fully mesh-independent non-linear topology optimization framework based on neural representations: Quasi-static problem","authors":"Zeyu Zhang, Yu Li, Weien Zhou, Wen Yao","doi":"10.1007/s11433-024-2576-7","DOIUrl":"10.1007/s11433-024-2576-7","url":null,"abstract":"<div><p>In artificial intelligence (AI) for science, the AI-empowered topology optimization methods have garnered sustained attention from researchers and achieved significant development. In this paper, we introduce the implicit neural representation (INR) from AI and the material point method (MPM) from the field of computational mechanics into topology optimization, resulting in a novel differentiable and fully mesh-independent topology optimization framework named MI-TONR, and it is then applied to nonlinear topology optimization (NTO) design. Within MI-TONR, the INR is combined with the topology description function to construct the design model, while implicit MPM is employed for physical response analysis. A skillful integration is achieved between the design model based on the continuous implicit representation field and the analysis model based on the Lagrangian particles. Along with updating parameters of the neural network (i.e., design variables), the structural topologies iteratively evolve according to the responses analysis results and optimization functions. The computational differentiability is ensured at every step of MI-TONR, enabling sensitivity analysis using automatic differentiation. In addition, we introduce the augmented Lagrangian Method to handle multiple constraints in topology optimization and adopt a learning rate adaptive adjustment scheme to enhance the robustness of the optimization process. Numerical examples demonstrate that MI-TONR can effectively conduct NTO design under large loads without any numerical techniques to mitigate numerical instabilities. Meanwhile, its natural satisfaction with the no-penetration condition facilitates the NTO design of considering contact. The infinite spatial resolution characteristic facilitates the generation of structural topology at multiple resolutions with clear and continuous boundaries.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"68 4","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143466048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}

引用次数: 0

Polarization structure transition of C-point singularities upon reflection c点奇点反射后的偏振结构跃迁

IF 6.4 1区物理与天体物理

Science China Physics, Mechanics & Astronomy Pub Date : 2025-02-20 DOI: 10.1007/s11433-024-2589-6

Weiming Zhen, Zhi-Cheng Ren, Xi-Lin Wang, Jianping Ding, Hui-Tian Wang

{"title":"Polarization structure transition of C-point singularities upon reflection","authors":"Weiming Zhen, Zhi-Cheng Ren, Xi-Lin Wang, Jianping Ding, Hui-Tian Wang","doi":"10.1007/s11433-024-2589-6","DOIUrl":"10.1007/s11433-024-2589-6","url":null,"abstract":"<div><p>This paper provides a comprehensive study of the polarization transition of reflected C-point singularities. The reflection of star- and lemon-type C-point paraxial vector beams at an air-dielectric interface is investigated. For small oblique incidences, a topological phase transition is observed exclusively in spin-maintained modes, manifesting as a shift from a vortex phase to a spin phase. Notably, as the incident angle ranges from 0 to 90 degrees, another topological phase transition occurs, the total spin components of the reflected field undergoing an interchange of topological charges (TCs), resulting in a type transition of the C-point from the star (lemon)-type to the lemon (star)-type. Furthermore, the concurrence of the C-point beam throughout the reflection process can be modulated by the incident angle, spanning almost the entire spectrum from 0 to 1. The longitudinal and transverse displacements of each spin component as well as the overall beam shifts of the reflected beam are further analyzed, revealing their dependence on the incident beam’s TC combination. These findings offer novel physical insights into polarization singularity-matter interactions, holding promise for advancing research in singular optics and its applications.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"68 4","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143466049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}

引用次数: 0

Attenuation of Richtmyer-Meshkov instability growth of fluid layer via double shock 双重激波对流体层richmyer - meshkov不稳定性增长的衰减

IF 6.4 1区物理与天体物理

Science China Physics, Mechanics & Astronomy Pub Date : 2025-02-20 DOI: 10.1007/s11433-024-2592-5

Chenren Chen, Jiaxuan Li, He Wang, Zhigang Zhai, Xisheng Luo

引用次数: 0

New discoveries of young stars revise our star formation history in the Taurus Molecular Cloud 年轻恒星的新发现修订了我们在金牛座分子云中的恒星形成历史

IF 6.4 1区物理与天体物理

Science China Physics, Mechanics & Astronomy Pub Date : 2025-02-19 DOI: 10.1007/s11433-025-2601-x

Gregory J. Herczeg

引用次数: 0

Space-based optical lattice clocks as gravitational wave detectors in search for new physics 作为引力波探测器的天基光学晶格钟在寻找新的物理学

IF 6.4 1区物理与天体物理

Science China Physics, Mechanics & Astronomy Pub Date : 2025-02-19 DOI: 10.1007/s11433-024-2573-3

Bo Wang, Bichu Li, Qianqian Xiao, Geyu Mo, Yi-Fu Cai

{"title":"Space-based optical lattice clocks as gravitational wave detectors in search for new physics","authors":"Bo Wang, Bichu Li, Qianqian Xiao, Geyu Mo, Yi-Fu Cai","doi":"10.1007/s11433-024-2573-3","DOIUrl":"10.1007/s11433-024-2573-3","url":null,"abstract":"<div><p>We investigate the sensitivity and performance of space-based optical lattice clocks (OLCs) in detecting gravitational waves, in particular the stochastic gravitational wave background (SGWB) at low frequencies (10<sup>−4</sup>, 1) Hz, which are inaccessible to ground-based detectors. We first analyze the response characteristics of a single OLC detector for SGWB detection and compare its sensitivity with that of laser interferometer space antenna (LISA). Due to longer arm lengths, space-based OLC detectors can exhibit unique frequency responses and enhance the capability to detect SGWB in the low-frequency range, but the sensitivity of a single OLC detector remains insufficient overall compared with LISA. Then, as a preliminary plan, we adopt a method of cross-correlation on two OLC detectors to improve the signal-to-noise ratio (SNR). This method leverages the uncorrelated origins but statistically similar properties of noise in two detectors while the SGWB signal is correlated between them, thus achieving effective noise suppression and sensitivity enhancement. Future advancements in OLC stability are expected to further enhance their detection performance. This work highlights the potential of OLC detectors as a promising platform for SGWB detection, offering complementary capabilities to LISA, and opening an observational window into more astrophysical sources and the early universe.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"68 4","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}

引用次数: 0

Nonlinear optical oscillation in on-chip erbium-doped lithium niobate microring resonators 片上掺铒铌酸锂微环谐振器的非线性光学振荡

IF 6.4 1区物理与天体物理

Science China Physics, Mechanics & Astronomy Pub Date : 2025-02-18 DOI: 10.1007/s11433-024-2591-x

Ru Zhang, Xianhong Zeng, Xueshan Zheng, Chen Yang, Dahuai Zheng, Hongde Liu, Xuanyi Yu, Feng Gao, Fang Bo, Yongfa Kong, Guoquan Zhang, Jingjun Xu

{"title":"Nonlinear optical oscillation in on-chip erbium-doped lithium niobate microring resonators","authors":"Ru Zhang, Xianhong Zeng, Xueshan Zheng, Chen Yang, Dahuai Zheng, Hongde Liu, Xuanyi Yu, Feng Gao, Fang Bo, Yongfa Kong, Guoquan Zhang, Jingjun Xu","doi":"10.1007/s11433-024-2591-x","DOIUrl":"10.1007/s11433-024-2591-x","url":null,"abstract":"<div><p>Erbium-doped lithium niobate (LN) on insulator active devices, such as lasers and amplifiers, have received increasing attention. The nonlinear optical oscillation in them at high power destabilizes the output of signals and cannot be ignored. In this study, we reported the experimental observation and theoretical analysis of the nonlinear optical oscillation in erbium-doped lithium niobate-on-insulator (LNOI) microring resonators while scanning the pump wavelength. Under the same pump power, the number of oscillation cycles decreases when the wavelength scanning rate increases from 10.6 to 33.9 nm/µs. A theoretical model based on the competition between the thermo-optic nonlinearity and the photorefractive effect was introduced to interpret the oscillation in transmission. A series of parameters were obtained from the comparison between the theoretical and experimental results; some of them, the relaxation rates of the thermal and the electric field, are significantly different from those of undoped LNOI microcavities. This work provides a valuable reference for future applications of active LNOI devices.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"68 4","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143455629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}

引用次数: 0

Eigen microstate analysis unveils climate dynamics 特征微态分析揭示了气候动力学

IF 6.4 1区物理与天体物理

Science China Physics, Mechanics & Astronomy Pub Date : 2025-02-18 DOI: 10.1007/s11433-024-2586-2

Hua Tu, Shang Wang, Jun Meng, Yongwen Zhang, Xiaosong Chen, Deliang Chen, Jingfang Fan

{"title":"Eigen microstate analysis unveils climate dynamics","authors":"Hua Tu, Shang Wang, Jun Meng, Yongwen Zhang, Xiaosong Chen, Deliang Chen, Jingfang Fan","doi":"10.1007/s11433-024-2586-2","DOIUrl":"10.1007/s11433-024-2586-2","url":null,"abstract":"<div><p>The Earth’s climate operates as a complex, dynamically interconnected system, driven by both anthropogenic and natural forcings and modulated by nonlinear interactions and feedback loops. This study employs a theoretical framework and the Eigen Microstate (EM) approach of statistical physics to examine global surface temperature variations since 1948, as revealed by a global reanalysis. We identified EMs significantly correlated with key climate phenomena such as the global monsoon system, tropical climates, and El Niño. Our analysis reveals that these EMs have increasingly influenced global surface temperature variations over recent decades, highlighting the critical roles of hemispheric differences, land-sea contrasts, and tropical climate fluctuations in a warming world. Additionally, we used model simulations from more than 10 Coupled Model Intercomparison Project Phase 6 (CMIP6) under three future climate scenarios to perform a comparative analysis of the changes in each EM contribution. The results indicate that under future warming scenarios, tropical climate fluctuations will become increasingly dominant, while traditional hemispheric and monsoonal patterns may decline. This shift underscores the importance of understanding tropical dynamics and their impact on global climate from a physics-based perspective. Our study provides a new perspective on understanding and addressing global climate change, enhancing the theoretical foundation of this critical field, and yielding findings with significant practical implications for improving climate models and developing effective mitigation and adaptation strategies.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"68 4","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143455557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}

引用次数: 0

Fermiology with nodal structures in nonsymmorphic superconductor LaNiGa2: A de Haas-van Alphen study 非对称超导体LaNiGa2中具有节点结构的费米学：A de Haas-van Alphen研究

IF 6.4 1区物理与天体物理

Science China Physics, Mechanics & Astronomy Pub Date : 2025-02-18 DOI: 10.1007/s11433-024-2559-x

Houpu Li, Ye Yang, Mengzhu Shi, Yingcai Qian, Senyang Pan, Kaibao Fan, Nan Zhang, Kaixin Tang, Hongyu Li, Zhiwei Wang, Jinglei Zhang, Chuanying Xi, Ziji Xiang, Xianhui Chen

{"title":"Fermiology with nodal structures in nonsymmorphic superconductor LaNiGa2: A de Haas-van Alphen study","authors":"Houpu Li, Ye Yang, Mengzhu Shi, Yingcai Qian, Senyang Pan, Kaibao Fan, Nan Zhang, Kaixin Tang, Hongyu Li, Zhiwei Wang, Jinglei Zhang, Chuanying Xi, Ziji Xiang, Xianhui Chen","doi":"10.1007/s11433-024-2559-x","DOIUrl":"10.1007/s11433-024-2559-x","url":null,"abstract":"<div><p>Topological metals possess various types of symmetry-protected degenerate band crossings. When a topological metal becomes superconducting, the low-energy electronic excitations stemming from the band crossings located close to the Fermi level may contribute to highly unusual pairing symmetry and superconducting states. In this work, we study the electronic band structure of the time-reversal symmetry breaking superconductor LaNiGa<sub>2</sub> by means of quantum oscillation measurements. A comprehensive investigation combining angle-resolved high-field de Haas-van Alphen (dHvA) spectroscopy and first-principles calculations reveals the fermiology of LaNiGa<sub>2</sub> and verifies its nonsymmorphic <i>Cmcm</i> lattice symmetry, which promises nodal band crossings pinned at the Fermi level with fourfold degeneracies. Moreover, such nodal structures, proposed to play a crucial role giving rise to the interorbital triplet pairing, are indeed captured by our dHvA analysis. Our results identify LaNiGa<sub>2</sub> as a prototypical topological crystalline superconductor and highlight the putative contribution of low-energy nodal quasiparticles to unconventional superconducting pairing.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"68 4","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143455558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}

引用次数: 0

Temporal-spatial distribution of YSOs nearby Taurus region 金牛座附近yso的时空分布

IF 6.4 1区物理与天体物理

Science China Physics, Mechanics & Astronomy Pub Date : 2025-02-18 DOI: 10.1007/s11433-024-2560-7

Jiaming Liu, Min Fang, Chao Liu, Xiaolong Wang, Wenyuan Cui, Licai Deng

{"title":"Temporal-spatial distribution of YSOs nearby Taurus region","authors":"Jiaming Liu, Min Fang, Chao Liu, Xiaolong Wang, Wenyuan Cui, Licai Deng","doi":"10.1007/s11433-024-2560-7","DOIUrl":"10.1007/s11433-024-2560-7","url":null,"abstract":"<div><p>The Taurus region is one of the most extensively studied star-forming regions (SFRs). Surveys indicate that the young stars in this region are comprised of young stellar objects (YSOs) that cluster in groups associated with the molecular cloud (Grouped Young Stellar Objects, GYSOs), and some older ones that are sparsely distributed throughout the region (Distributed Young Stellar Objects, DYSOs). To bridge the age gap between the GYSOs (⩽5 Myr) and the DYSOs (10–20 Myr), we conducted a survey to search for new YSOs in this direction. Based on infrared color excesses and Li I absorption lines, we identified 145 new YSOs. Combining these with the previously identified GYSOs and DYSOs, we constructed a sample of 519 YSOs that encompass the entire region. Subsequently, we calculated the ages of the samples based on their proximity to the local bubble. The age versus distance to the local bubble (<i>D</i><sub>LB</sub>) relationship for the DYSOs shows a clear trend: the farther they are from the local bubble, the younger they are, which is consistent with the supernovae-driven formation scenario of the local bubble. The GYSOs also exhibit a mild age versus <i>D</i><sub>LB</sub> trend. However, they are significantly younger and are mostly confined to distances of 120 to 220 pc. Considering their distribution in the age versus <i>D</i><sub>LB</sub> space is well separated from the older DYSOs, they may also be products of the local bubble but formed in more recent and localized events.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"68 4","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143455559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}

引用次数: 0