Acta Mechanica Sinica最新文献_第5页

Advances in the study of high-speed attachment-line boundary layer transition 高速附线边界层过渡的研究进展

IF 4.6 2区工程技术

Acta Mechanica Sinica Pub Date : 2025-07-10 DOI: 10.1007/s10409-025-25323-x

Youcheng Xi (, ), Peisen Lu (, ), Song Fu (, )

{"title":"Advances in the study of high-speed attachment-line boundary layer transition","authors":"Youcheng Xi \u0000 (, ), Peisen Lu \u0000 (, ), Song Fu \u0000 (, )","doi":"10.1007/s10409-025-25323-x","DOIUrl":"10.1007/s10409-025-25323-x","url":null,"abstract":"<div><p>This review provides recent advancements in the study of attachment-line boundary layer transition with emphasis on high-speed configurations. As a critical factor influencing aerodynamic performance and thermal management in supersonic and hypersonic systems, the transition mechanisms of three-dimensional attachment-line boundary layers have emerged as a pivotal research frontier in high-speed aerodynamics. This review systematically summarizes the evolution of research on attachment-line boundary layer transition, from early theoretical foundations to modern computational and experimental breakthroughs. A critical examination is presented for two pivotal challenges in high-speed attachment-line boundary layer transition: The resolution of the Gaillard paradox and the leading-edge contamination mechanism. Through systematic synthesis of theoretical developments and empirical evidence, this review identifies critical knowledge gaps while proposing novel methodological approaches for attachment-line boundary layer transition analysis. The review culminates in a strategic framework outlining promising avenues for both fundamental inquiry into attachment-line phenomena and applied engineering solutions in flow control strategies.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"41 7","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145163618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Towards the future of physics- and data-guided AI frameworks in computational mechanics 面向计算力学中物理和数据引导的AI框架的未来

IF 4.6 2区工程技术

Acta Mechanica Sinica Pub Date : 2025-07-09 DOI: 10.1007/s10409-025-25340-x

Jinshuai Bai (, ), Yizheng Wang (, ), Hyogu Jeong, Shiyuan Chu (, ), Qingxia Wang, Laith Alzubaidi, Xiaoying Zhuang (, ), Timon Rabczuk, Yi Min Xie (, ), Xi-Qiao Feng (, ), Yuantong Gu

{"title":"Towards the future of physics- and data-guided AI frameworks in computational mechanics","authors":"Jinshuai Bai \u0000 (, ), Yizheng Wang \u0000 (, ), Hyogu Jeong, Shiyuan Chu \u0000 (, ), Qingxia Wang, Laith Alzubaidi, Xiaoying Zhuang \u0000 (, ), Timon Rabczuk, Yi Min Xie \u0000 (, ), Xi-Qiao Feng \u0000 (, ), Yuantong Gu","doi":"10.1007/s10409-025-25340-x","DOIUrl":"10.1007/s10409-025-25340-x","url":null,"abstract":"<div><p>The integration of physics-based modelling and data-driven artificial intelligence (AI) has emerged as a transformative paradigm in computational mechanics, This perspective reviews the development and current status of AI-empowered frameworks, including data-driven methods, physics-informed neural networks, and neural operators, While these approaches have demonstrated significant promise, challenges remain in terms of robustness, generalisation, and computational efficiency, We delineate four promising research directions: (1) Modular neural architectures inspired by traditional computational mechanics, (2) physics informed neural operators for resolution-invariant operator learning, (3) intelligent frameworks for multiphysics and multiscale biomechanics problems, and (4) structural optimisation strategies based on physics constraints and reinforcement learning, These directions represent a shift toward foundational frameworks that combine the strengths of physics and data, opening new avenues for the modelling, simulation, and optimisation of complex physical systems.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"41 7","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145163930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Unraveling the formation and stabilization of vesicle penetration pore by molecular dynamics simulations 用分子动力学模拟揭示囊泡渗透孔的形成和稳定

IF 4.6 2区工程技术

Acta Mechanica Sinica Pub Date : 2025-07-09 DOI: 10.1007/s10409-025-25419-x

Zhi Zheng (, ), Mingkun Zhang (, ), Qing Yang (, ), Mian Long (, ), Shouqin Lü (, )

{"title":"Unraveling the formation and stabilization of vesicle penetration pore by molecular dynamics simulations","authors":"Zhi Zheng \u0000 (, ), Mingkun Zhang \u0000 (, ), Qing Yang \u0000 (, ), Mian Long \u0000 (, ), Shouqin Lü \u0000 (, )","doi":"10.1007/s10409-025-25419-x","DOIUrl":"10.1007/s10409-025-25419-x","url":null,"abstract":"<div><p>The formation of donut-shaped penetration pore upon membrane fusion in a closed lipid membrane system is of biological significance, since such the structures extensively exist in living body with various functions. However, the related formation dynamics is unclear because of the limitation of experimental techniques. This work developed a new model of intra-vesicular fusion to elaborate the formation and stabilization of penetration pores by employing molecular dynamics simulations, based on simplified spherical lipid vesicle system, and investigated the regulation of membrane lipid composition. Results showed that penetration pore could be successfully formed based on the strategy of membrane fusion. The ease of intra-vesicular fusion and penetration pore formation was closely correlated with the lipid curvature properties, where negative spontaneous curvature of lipids seemed to be unfavorable for intra-vesicle fusion. Furthermore, the inner membrane tension around the pore was much larger than other regions, which governed the penetration pore size and stability. This work provided basic understanding for vesicle penetration pore formation and stabilization mechanisms.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"41 7","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145163931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Yield and buckling stress limits in topology optimization of multiscale structures 多尺度结构拓扑优化中的屈服和屈曲应力极限

IF 4.6 2区工程技术

Acta Mechanica Sinica Pub Date : 2025-07-09 DOI: 10.1007/s10409-025-25385-x

Christoffer Fyllgraf Christensen, Fengwen Wang (, ), Ole Sigmund

{"title":"Yield and buckling stress limits in topology optimization of multiscale structures","authors":"Christoffer Fyllgraf Christensen, Fengwen Wang \u0000 (, ), Ole Sigmund","doi":"10.1007/s10409-025-25385-x","DOIUrl":"10.1007/s10409-025-25385-x","url":null,"abstract":"<div><p>This study presents an extension of multiscale topology optimization by integrating both yield stress and local/global buckling considerations into the design process. Building upon established multiscale methodologies, we develop a new framework incorporating yield stress limits either as constraints or objectives alongside previously established local and global buckling constraints. This approach significantly refines the optimization process, ensuring that the resulting designs meet mechanical performance criteria and adhere to critical material yield constraints. First, we establish local density-dependent von Mises yield surfaces based on local yield estimates from homogenization-based analysis to predict the local yield limits of the homogenized materials. Then, these local yield-based load factors are combined with local and global buckling criteria to obtain topology optimized designs that consider yield and buckling failure on all levels. This integration is crucial for the practical application of optimized structures in real-world scenarios, where material yield and stability behavior critically influence structural integrity and durability. Numerical examples demonstrate how optimized designs depend on the stiffness to yield ratio of the considered building material. Despite the foundational assumption of the separation of scales, the de-homogenized structures, even at relatively coarse length scales, exhibit a remarkably high degree of agreement with the corresponding homogenized predictions.</p></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"41 7","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10409-025-25385-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145163932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The physics of icing drops under complex conditions 在复杂条件下结冰的物理现象

IF 4.6 2区工程技术

Acta Mechanica Sinica Pub Date : 2025-07-08 DOI: 10.1007/s10409-025-25318-x

Feng Wang (, ), Hao Zeng (, ), Sergio Peralta, Julien Sebilleau, Chao Sun (, ), Dominique Legendre

{"title":"The physics of icing drops under complex conditions","authors":"Feng Wang \u0000 (, ), Hao Zeng \u0000 (, ), Sergio Peralta, Julien Sebilleau, Chao Sun \u0000 (, ), Dominique Legendre","doi":"10.1007/s10409-025-25318-x","DOIUrl":"10.1007/s10409-025-25318-x","url":null,"abstract":"<div><p>Icing of water droplets is a ubiquitous phenomenon with significant implications across natural systems and industrial applications. Despite extensive research, the intricate interplay among heat transfer, mass transport, and phase change during droplet freezing remains incompletely understood, particularly in the context of multiscale dynamics and environmental dependencies. This review critically examines recent advances in uncovering the fundamental mechanisms of droplet icing through experimental, theoretical, and computational approaches. We begin by revisiting the classical tip singularity problem in the freezing of pure water droplets, analyzing its mathematical formulation and physical significance. Subsequent sections explore how environmental boundary conditions and multicomponent effects influence freezing kinetics, solute redistribution, and ice morphology. Furthermore, we evaluate emerging hybrid numerical frameworks that resolve coupled multiphase physics during solidification processes. Finally, we identify key challenges and open questions that require further investigation in this field.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"41 7","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145162978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Solids in nano-scales: extreme strength and elasticity 纳米级固体：极高的强度和弹性

IF 4.6 2区工程技术

Acta Mechanica Sinica Pub Date : 2025-07-07 DOI: 10.1007/s10409-025-25334-x

Wei Yang (, ), Hong-Tao Wang (, ), Hao-Fei Zhou (, ), Ye-Qiang Bu (, ), Zheng-Ping Su (, )

{"title":"Solids in nano-scales: extreme strength and elasticity","authors":"Wei Yang \u0000 (, ), Hong-Tao Wang \u0000 (, ), Hao-Fei Zhou \u0000 (, ), Ye-Qiang Bu \u0000 (, ), Zheng-Ping Su \u0000 (, )","doi":"10.1007/s10409-025-25334-x","DOIUrl":"10.1007/s10409-025-25334-x","url":null,"abstract":"<div><p>Solids in nano-scales hold the promise to exhibit extreme strength and elasticity due to the absence of interior defects and the designability of micro-arrangements. A nano-scaled bulk sample can be produced by diamond, ice, metallic twins, high entropy alloy (HEA), or cubic boron nitride (cBN). A loading stage capable of 4-DoF movements was designed and built to achieve multi-axial mechanical loading inside a transmission electronic microscope chamber with sub-nanometer loading precision. For single crystal diamond in the shape of nano-needles, we were able to achieve an extreme bending strength of 125 GPa at the tensile side, approaching the theoretical strength of diamond. For ice fibers of sub-micron radius, an extreme elastic strain of 10.9% was acquired, far exceeding the previous record of 0.3% for the elastic strain achievable by ice. For metallic twin specimens made by nano-welding, a shear strain as large as 364% was recorded parallel to the twin boundary. Cyclic shear loading aligned with the twin boundary would drive an up-and-down sweeping movement of the low-angle grain boundary, as composed by an array of dislocations. The sweep of the grain boundary effectively cleanses the lattice defects and creates a feasible scenario of unlimited cyclic endurance. For a HEA dog-bone specimen in nano-scale, an extreme elastic strain of about 10% was achieved. At this level of mechanical straining, stretch-induced melting for crystalline metals, as envisaged by Lindemann a century ago, was realized. For cBN crystals, a fracture path inclined to the stacking hexagon planes would result in a new failure mechanism of layered decohesion, triggered by the extremely large elastic strain (>7%) along the edge of the submicron-scaled specimen. These results indicate ample room for upgrading the mechanical behaviour of solids in nano-scales.</p></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"41 7","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145162568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A conservative wavelet upwind scheme for compressible flows 可压缩流的保守小波逆风格式

IF 4.6 2区工程技术

Acta Mechanica Sinica Pub Date : 2025-07-07 DOI: 10.1007/s10409-025-25178-x

Bing Yang (, ), Xiaojing Liu (, ), Youhe Zhou (, ), Jizeng Wang (, )

{"title":"A conservative wavelet upwind scheme for compressible flows","authors":"Bing Yang \u0000 (, ), Xiaojing Liu \u0000 (, ), Youhe Zhou \u0000 (, ), Jizeng Wang \u0000 (, )","doi":"10.1007/s10409-025-25178-x","DOIUrl":"10.1007/s10409-025-25178-x","url":null,"abstract":"<div><p>In this paper, we develop a fourth-order conservative wavelet-based shock-capturing scheme. The scheme is constructed by combining a wavelet collocation upwind method with the monotonic tangent of hyperbola for interface capturing (THINC) technique. We employ boundary variation diminishing (BVD) reconstruction to enhance the scheme’s effectiveness in handling shocks. First, we prove that wavelet collocation upwind schemes based on interpolating wavelets can be reformulated into a conservative form within the framework of wavelet theory, forming the foundation of the proposed scheme. The new fourth-order accurate scheme possesses significantly better spectral resolution than the fifth- and even seventh-order WENO-Z (weighted essentially non-oscillatory) schemes over the entire wave-number range. Moreover, the inherent low-pass filtering property of the wavelet bases allows them to filter high-frequency numerical oscillations, endowing the wavelet upwind scheme with robustness and accuracy in solving problems under extreme conditions. Notably, due to the wavelet multi-resolution approximation, the proposed scheme possesses a distinctive shape-preserving property absent in the WENO-Z schemes and the fifth-order schemes with BVD reconstruction based on polynomials. Furthermore, compared to the fifth-order scheme with BVD reconstruction based on polynomials—which is significantly superior to the WENO schemes—the proposed scheme further enhances the ability to capture discontinuities.</p></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"41 7","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145163092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Perspectives on low-Reynolds-number aerodynamics: shape, motion and structure 低雷诺数空气动力学的展望：形状、运动和结构

IF 4.6 2区工程技术

Acta Mechanica Sinica Pub Date : 2025-07-07 DOI: 10.1007/s10409-025-25312-x

Die Chen (, ), Lin Fu (, ), Csaba Hefler, Tian Ji (, ), Ryusuke Noda (, ), Michael Pittman (, ), Huihe Qiu (, ), Wei Shyy (, ), Qing Zhang (, )

{"title":"Perspectives on low-Reynolds-number aerodynamics: shape, motion and structure","authors":"Die Chen \u0000 (, ), Lin Fu \u0000 (, ), Csaba Hefler, Tian Ji \u0000 (, ), Ryusuke Noda \u0000 (, ), Michael Pittman \u0000 (, ), Huihe Qiu \u0000 (, ), Wei Shyy \u0000 (, ), Qing Zhang \u0000 (, )","doi":"10.1007/s10409-025-25312-x","DOIUrl":"10.1007/s10409-025-25312-x","url":null,"abstract":"<div><p>Some of the most interesting areas in aerospace science and technologies are on either higher, faster, and larger systems or lower, slower, and smaller flying capabilities. In this paper, we present our perspectives on the aerodynamics related to small, fixed-wing as well as flapping-wing flight vehicles. From an evolutionary viewpoint, flyers have gone through many iterations, adaptations, and optimizations to balance their biological functions, including flight. In the low-Reynolds-number regime, the aerodynamic characteristics around a solid object differ from those observed at the scale of passenger-airplanes. Consequently, the optimal airfoil and wing shapes vary with vehicle size. As vehicle dimensions vary, non-proportional scaling between surface areas and weight shifts the dominance of physical mechanisms, leading to distinct operational parameters and technical requirements. With smaller flight vehicles, structural flexibility as well as anisotropic material properties become more pronounced, which causes qualitative changes in aerodynamics. The flapping motion of the wings, the interactions between wings, the synergistic characteristics of wing and tail, and the development of soft structures for better agility and flight performance are discussed. Low-Reynolds-number aerodynamics require collaborative innovation to optimize shape, motion, and structure of vehicles in accordance with the scaling laws. Together, progress on these fronts is reshaping the design paradigm of air vehicles and other types of robots with shrinking physical dimensions and more versatile capabilities to meet wider ranges of missions.</p></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"41 7","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145163094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Onward and upward—Celebrating the 40th anniversary of Acta Mechanica Sinica 前进向上——庆祝《力学学报》创刊40周年

IF 4.6 2区工程技术

Acta Mechanica Sinica Pub Date : 2025-07-07 DOI: 10.1007/s10409-025-25371-x

Xiaojin Zheng, Yujie Wei

引用次数: 0

3D trajectory reconstruction of moving points based on asynchronous cameras 基于异步摄像机的运动点三维轨迹重建

IF 4.6 2区工程技术

Acta Mechanica Sinica Pub Date : 2025-07-05 DOI: 10.1007/s10409-025-25322-x

Huayu Huang (, ), Yang Shang (, ), Banglei Guan (, ), Qifeng Yu (, )

{"title":"3D trajectory reconstruction of moving points based on asynchronous cameras","authors":"Huayu Huang \u0000 (, ), Yang Shang \u0000 (, ), Banglei Guan \u0000 (, ), Qifeng Yu \u0000 (, )","doi":"10.1007/s10409-025-25322-x","DOIUrl":"10.1007/s10409-025-25322-x","url":null,"abstract":"<div><p>Photomechanics is a crucial branch of solid mechanics. The localization of point targets constitutes a fundamental problem in optical experimental mechanics, with extensive applications in various missions of unmanned aerial vehicles. Localizing moving targets is crucial for analyzing their motion characteristics and dynamic properties. Reconstructing the trajectories of points from asynchronous cameras is a significant challenge. It encompasses two coupled sub-problems: Trajectory reconstruction and camera synchronization. Present methods typically address only one of these sub-problems individually. This paper proposes a 3D trajectory reconstruction method for point targets based on asynchronous cameras, simultaneously solving both sub-problems. Firstly, we extend the trajectory intersection method to asynchronous cameras to resolve the limitation of traditional triangulation that requires camera synchronization. Secondly, we develop models for camera temporal information and target motion, based on imaging mechanisms and target dynamics characteristics. The parameters are optimized simultaneously to achieve trajectory reconstruction without accurate time parameters. Thirdly, we optimize the camera rotations alongside the camera time information and target motion parameters, using tighter and more continuous constraints on moving points. The reconstruction accuracy is significantly improved, especially when the camera rotations are inaccurate. Finally, the simulated and real-world experimental results demonstrate the feasibility and accuracy of the proposed method. The real-world results indicate that the proposed algorithm achieved a localization error of 112.95 m at an observation distance range of 15–20 km.</p></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"41 7","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145162451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0