International Journal of Engineering Science最新文献_第9页

Coupled chemo-mechanical constitutive equations and residual stress evolution of swelling hydrogels 溶胀水凝胶的化学-力学耦合本构方程及残余应力演化

IF 5.7 1区工程技术 Q1 ENGINEERING, MULTIDISCIPLINARY

International Journal of Engineering Science

Pub Date : 2025-12-01 Epub Date: 2025-09-27 DOI: 10.1016/j.ijengsci.2025.104390

Vivek Kumar Singh, Krishnendu Haldar

Hydrogels are cross-linked polymeric materials capable of undergoing large deformation in response to external stimuli, such as chemical gradients and mechanical loading. This article presents a coupled chemo-mechanical model of hydrogel undergoing substantial swelling. A multiplicative decomposition-based framework is adopted to represent simultaneous swelling and mechanical deformation in a consistent thermodynamic way. A nonlinear modified hyperelastic Yeoh–Fleming model is considered for the fully swollen hydrogel to describe the strain energy of the polymer network and is calibrated from the available experiments. After calibrating the model using uniaxial stretching for different volume fractions of the polymer network, the model is then benchmarked with equi-biaxial and pure shear responses. The model calibration at different polymer network volume fractions also allows evolution of the Yeoh–Fleming model parameters with polymer network concentration. Finally, we combine the free energy of mixing of solvent and polymer network and the strain energy of polymer network to solve a coupled boundary value problem (BVP) of free swelling. The solution predicts free swelling of hydrogel and the evolution of residual stresses induced by a slow diffusion phenomenon. The numerical results presented here may provide guidance for significant applications of hydrogels in soft robotics, drug delivery and biomedical systems.

水凝胶是一种交联聚合物材料，能够在外部刺激（如化学梯度和机械载荷）下发生大变形。本文提出了水凝胶剧烈膨胀的化学-力学耦合模型。采用基于乘法分解的框架，以一致的热力学方式表示膨胀和机械变形同时发生。考虑了完全膨胀水凝胶的非线性修正超弹性yeo - fleming模型来描述聚合物网络的应变能，并根据现有的实验进行了校准。在对聚合物网络的不同体积分数使用单轴拉伸校准模型后，然后对模型进行等双轴和纯剪切响应的基准测试。在不同聚合物网络体积分数下的模型校准也允许yeo - fleming模型参数随聚合物网络浓度的变化。最后，结合溶剂与聚合物网络混合的自由能和聚合物网络的应变能，求解了自由膨胀的耦合边值问题。该解决方案预测了水凝胶的自由膨胀和由缓慢扩散现象引起的残余应力的演变。本文给出的数值结果可能为水凝胶在软机器人、药物输送和生物医学系统中的重要应用提供指导。

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引用次数: 0

Wave dynamics in the drift-flux two-phase flow model 漂通量两相流模型中的波动动力学

IF 5.7 1区工程技术 Q1 ENGINEERING, MULTIDISCIPLINARY

International Journal of Engineering Science

Pub Date : 2025-12-01 Epub Date: 2025-09-22 DOI: 10.1016/j.ijengsci.2025.104385

Sumanta Shagolshem , Dia Zeidan , K.V. Nagaraja

The present study provides a comprehensive symmetry analysis for a simplified two-phase flow model with the logarithmic equation of state. Under a one-parameter Lie group of transformations, we generate the local symmetry of the model, preserving the invariance of the system. Subsequently, we classify one-dimensional optimal subalgebras, which is a systematic framework for computing invariant solutions efficiently. With the characteristic method, we developed explicit solutions for the model utilizing the optimal subalgebras. Further, we prove that nonlocal symmetries exist for the considered model, and then some new exact solutions were developed where local symmetries cannot provide. Furthermore, the existence of the nonlinear self-adjointness property of the model is demonstrated with the construction of conservation laws. This study concludes by examining the complex hyperbolic nature, such as

C^{1}

-wave, characteristic shock, and their interaction with one of the solutions derived from nonlocal symmetry, highlighting the critical wave dynamics of the model.

本文对一个简化的两相流模型的对数状态方程进行了全面的对称性分析。在单参数李群变换下，我们生成了模型的局部对称性，保持了系统的不变性。然后，我们对一维最优子代数进行分类，这是一个有效计算不变解的系统框架。利用特征方法，利用最优子代数，给出了模型的显式解。进一步证明了所考虑的模型存在非局部对称性，并给出了局部对称性不能提供的精确解。进一步，通过构造守恒律证明了模型的非线性自伴随性质的存在性。本研究通过研究复杂的双曲性质，如c1波，特征激波，以及它们与非局部对称解之一的相互作用来结束，突出了模型的临界波动动力学。

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引用次数: 0

Elastohydrodynamic instabilities in pressure-driven flow through a poroelastic channel 孔隙弹性通道中压力驱动流体的弹性水动力不稳定性

IF 5.7 1区工程技术 Q1 ENGINEERING, MULTIDISCIPLINARY

International Journal of Engineering Science

Pub Date : 2025-12-01 Epub Date: 2025-09-15 DOI: 10.1016/j.ijengsci.2025.104379

Ramkarn Patne

The linear stability analysis of a pressure-driven flow through a saturated poroelastic channel sandwiched between two impermeable rigid walls is carried out in the present study. Mixture theory is employed to describe the dynamics of the interstitial fluid and elastic solid matrix. The resulting eigenvalue problem is solved using the pseudo-spectral method. Without the poroelastic solid matrix, the flow under consideration reduces to the classical plane Poiseuille flow for which the linear stability analysis predicts critical Reynolds number,

R e_{c} = 5772

. However, the present study, predicts that

R e_{c}

could be as low as 5 for the flow under consideration owing to the deformability of the solid matrix. Further analysis reveals the existence of three new modes of instability. For low

R e

, mode I dominates the instability, while at high

R e

, mode III dominates the instability with characteristic scaling

Γ_{c} \sim 1 / R e

where

Γ_{c}

is a measure of the deformability of the solid matrix. The driving mechanism of the predicted instability is found to be the coupling between the fluid and solid due to the pressure perturbation. The energy exchange between the base state velocity gradient and normal velocity perturbation via the convection term in the linearised Navier–Stokes equation plays a supporting role to the pressure perturbations in introducing unstable modes.

本文对夹在两个不透水刚性壁面之间的饱和孔弹性通道进行了压力驱动流动的线性稳定性分析。混合理论用于描述间隙流体和弹性固体基质的动力学。利用伪谱法求解得到的特征值问题。在没有孔隙弹性固体基体的情况下，所考虑的流动可以简化为经典的平面泊泽维尔流动，线性稳定性分析预测其临界雷诺数Rec=5772。然而，本研究预测，由于固体基体的可变形性，所考虑的流动的Rec可能低至5。进一步分析表明存在三种新的不稳定模态。对于低Re， I型主导不稳定性，而在高Re时，III型主导不稳定性，其特征标度为Γc ~ 1/Re，其中Γc是固体基体变形能力的度量。发现预测的不稳定性的驱动机制是由于压力扰动引起的流体与固体之间的耦合。线性化Navier-Stokes方程中基态速度梯度与法向速度扰动之间通过对流项的能量交换对引入不稳定模态的压力扰动起支持作用。

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引用次数: 0

Capillary force on the inner wall of the mesh atomizer influencing the size of the droplets 网状雾化器内壁毛细力对雾滴大小的影响

IF 5.7 1区工程技术 Q1 ENGINEERING, MULTIDISCIPLINARY

International Journal of Engineering Science

Pub Date : 2025-12-01 Epub Date: 2025-10-16 DOI: 10.1016/j.ijengsci.2025.104399

Fan Zhang, Guan-Xian Chen, Zhen-Zhen Gui, Jian-Hui Zhang, Shao-Zheng Deng, Fu-Hai Wu, Yin-He Wang

Piezoelectric atomizer is widely used in inhalation therapy field, where the drug deposition depth depends on the size of the atomized droplet. Herein, the diameter of the droplet was regulated by changing the wettability of the inner wall of the tapered hole of atomizers. The dynamic cone angle-capillary (DCA-C) model is established, where the contact angle of the inner wall θ and the cone angle α are the two key parameters to influence of the droplet size. When θ>π/2+α/2, the droplet size decreases; when θ<π/2+α/2, the droplet size increases. The experiment results show that after non-wetting treatment of the metal sheet of the atomizer, the contact angle θ=162°, and the atomized droplet diameter is 1.246 μm, which is decreased by 83.9%; after wetting treatment, the contact angle θ=66°, and the atomized droplet diameter is 9.851 μm, which is increased by 27.3%. It demonstrates that the DCA-C model can better explain the mechanism of piezoelectric atomization, where the capillary force plays a crucial role in regulating droplet size.

压电雾化器广泛应用于吸入治疗领域，其药物沉积深度取决于雾化液滴的大小。本文通过改变喷嘴锥形孔内壁的润湿性来调节液滴的直径。建立了动态锥角-毛细管（DCA-C）模型，其中内壁接触角θ和锥角α是影响液滴大小的两个关键参数。当θ>；π/2+α/2时，液滴尺寸减小；当θ<；π/2+α/2时，液滴尺寸增大。实验结果表明：对雾化器金属板进行非润湿处理后，接触角θ=162°，雾化液滴直径为1.246 μm，减小了83.9%；润湿处理后，接触角θ=66°，雾化液滴直径为9.851 μm，增大27.3%。结果表明，DCA-C模型能较好地解释压电雾化的机理，其中毛细力对液滴大小的调节起着至关重要的作用。

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引用次数: 0

Slow translation of a slightly deformed spherical fluid drop in an arbitrary unsteady viscous flow 任意非定常粘性流动中轻微变形的球形液滴的缓慢平移

IF 5.7 1区工程技术 Q1 ENGINEERING, MULTIDISCIPLINARY

International Journal of Engineering Science

Pub Date : 2025-12-01 Epub Date: 2025-10-16 DOI: 10.1016/j.ijengsci.2025.104401

Chennuri Dhanya , Jai Prakash , Huan J. Keh

The present study investigates the translational motion of a slightly deformed spherical fluid drop suspended in an arbitrary unsteady viscous fluid. The analysis is conducted under the assumption of a negligible Reynolds number, indicating a scenario where the induced stresses are slightly higher than the interfacial tension. Consequently, the drop undergoes a slight deformation but remains intact without breaking. The flow fields in both the interior and exterior of the drop are governed by the unsteady Stokes equations, which are solved asymptotically using a method of regular perturbation expansions under appropriate boundary conditions. The deviation from the spherical shape is quantified by a small parameter referred to as the deformation parameter, which is taken as the perturbation parameter. A complete general solution to the unsteady Stokes equations is employed to solve the equations governing the fluid flow. The hydrodynamic forces on the drop are then determined and expressed in terms of Faxén’s law for an arbitrary ambient flow field. The hydrodynamic problem is tackled up to the first order of the deformation parameter, disregarding higher-order terms. Closed-form expressions for the hydrodynamic drag force acting on the drop are derived for the specific scenarios of prolate and oblate spheroidal drops. The hydrodynamic forces obtained in the present study agree with the respective hydrodynamic forces experienced by prolate and oblate spheroidal drops in the limiting case of steady flow, as existing in the literature.

本文研究了悬浮在任意非定常粘性流体中的微变形球形液滴的平移运动。分析是在假设雷诺数可以忽略的情况下进行的，这表明在这种情况下，诱导应力略高于界面张力。因此，液滴经历了轻微的变形，但保持完整而不破裂。液滴内部和外部的流场由非定常Stokes方程控制，该方程在适当的边界条件下用正则摄动展开法渐近求解。从球体形状的偏差是量化的一个小参数称为变形参数，这是作为摄动参数。采用非定常Stokes方程的完全通解来求解控制流体流动的方程。在任意环境流场下，液滴上的水动力被确定并以faxsamn定律表示。水动力问题处理到变形参数的一阶，忽略了高阶项。针对长形液滴和扁球形液滴的具体情况，推导了作用于液滴的水动力阻力的封闭表达式。本研究得到的水动力与文献中存在的长形液滴和扁球形液滴在稳定流动的极限情况下所经历的水动力相一致。

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引用次数: 0

Topology optimization of 2D chiral metamaterials with dilatation-shear and shear-shear coupling capabilities 具有膨胀-剪切和剪切-剪切耦合能力的二维手性超材料拓扑优化

IF 5.7 1区工程技术 Q1 ENGINEERING, MULTIDISCIPLINARY

International Journal of Engineering Science

Pub Date : 2025-12-01 Epub Date: 2025-09-04 DOI: 10.1016/j.ijengsci.2025.104367

Mohamed Shaat , Xin-Lin Gao

Metamaterials with chiral microstructures exhibit unique mechanical coupling among various deformation modes. Traditional approaches for designing such materials rely heavily on discrete models and unit cells with predefined architectures, and hence it has been challenging to develop methodologies that can explore a broad range of chiral configurations and optimize the mechanical coupling behavior without being constrained by specific unit cell geometries. In the current study, a new multi-objective topology optimization (TO) method is developed for designing 2D chiral metamaterials with prescribed mechanical coupling among dilatation and two distinct shear deformation modes. The new method incorporates material symmetry constraints (including the

C_{2}

and

C_{4}

symmetries) into the TO process. A strain energy-based homogenization approach is adopted to determine the effective elastic stiffness matrix for each periodic chiral metamaterial. The TO process begins with maximizing the trace of the stiffness matrix to avoid cases with vanishing bulk or shear moduli, which is followed by maximizing/minimizing a selected off-diagonal component to optimize the dilatation-shear or shear-shear coupling. The proposed method successfully identifies optimal topologies that exhibit chiral layouts consistent with the imposed material symmetry constraints, and it maximizes mechanical coupling among dilatation and shear deformation modes. This newly developed method enables the exploration of diverse chiral material configurations, achieving optimized mechanical coupling without relying on a specific unit cell architecture.

具有手性微结构的超材料在各种变形模式之间表现出独特的力学耦合。设计此类材料的传统方法严重依赖于具有预定义架构的离散模型和单元格，因此开发能够探索广泛的手性配置并优化机械耦合行为的方法一直具有挑战性，而不受特定单元格几何形状的限制。在本研究中，提出了一种新的多目标拓扑优化（TO）方法，用于设计具有规定的膨胀和两种不同剪切变形模式之间的力学耦合的二维手性超材料。新方法将材料对称约束（包括C2和C4对称）纳入到TO工艺中。采用基于应变能的均匀化方法确定了各周期手性超材料的有效弹性刚度矩阵。TO过程首先最大化刚度矩阵的轨迹，以避免体积模量或剪切模量消失的情况，然后最大化/最小化选定的非对角线分量，以优化膨胀-剪切或剪切-剪切耦合。该方法成功地识别出符合材料对称约束的手性布局的最优拓扑结构，并最大限度地提高了膨胀和剪切变形模式之间的力学耦合。这种新开发的方法可以探索不同的手性材料结构，实现优化的机械耦合，而不依赖于特定的单元胞结构。

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引用次数: 0

Predictive asymptotic models of damage evolution in thin adhesives with tension–compression asymmetry 具有拉压不对称的薄胶粘剂损伤演化的预测渐近模型

IF 5.7 1区工程技术 Q1 ENGINEERING, MULTIDISCIPLINARY

International Journal of Engineering Science

Pub Date : 2025-12-01 Epub Date: 2025-09-18 DOI: 10.1016/j.ijengsci.2025.104384

Michele Serpilli , Raffaella Rizzoni , Frédéric Lebon

In structural engineering, accurate modeling of material damage is crucial, particularly the tension–compression asymmetry observed in quasi-brittle materials and adhesive joints. While cohesive interface models are commonly employed in the analysis of bonded structures, the parameters of these models frequently lack a direct correlation with the physical properties of the adhesive layer. To address this issue and capture the tension–compression asymmetry, this study uses asymptotic analysis to derive two new interface damage models (termed F1d and F2d) from a thin damaging interphase. The proposed models are formulated within a thermodynamically consistent framework. The F1d model uses a single damage variable with an asymmetric evolution law, whereas the more advanced F2d model uses separate variables for tensile and compressive damage, enabling independent evolution kinetics. To bridge the gap between scales and link macroscopic damage to micro-defect evolution, the new models are coupled with two micromechanical schemes: the non-interacting Kachanov–Sevostianov model and the Mori–Tanaka–Benveniste model, the latter of which accounts for defect interactions. The theoretical formulations of the models are presented, and their predictive capabilities are demonstrated through numerical simulations of a bonded joint under axial loading.

在结构工程中，材料损伤的精确建模是至关重要的，特别是在准脆性材料和粘接接头中观察到的拉压不对称。粘结界面模型通常用于粘结结构的分析，但这些模型的参数往往与粘结层的物理性质缺乏直接的相关性。为了解决这一问题并捕获拉压不对称，本研究使用渐近分析从薄损伤界面中推导出两种新的界面损伤模型（称为F1d和F2d）。所提出的模型是在热力学一致的框架内制定的。F1d模型使用具有非对称演化规律的单一损伤变量，而更先进的F2d模型使用单独的拉伸和压缩损伤变量，实现独立的演化动力学。为了弥合尺度之间的差距，并将宏观损伤与微观缺陷演变联系起来，新模型与两种微观力学方案相结合：非相互作用的Kachanov-Sevostianov模型和Mori-Tanaka-Benveniste模型，后者考虑缺陷相互作用。给出了模型的理论表达式，并通过轴向载荷作用下的数值模拟验证了模型的预测能力。

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引用次数: 0

A peridynamic approach to analysis of coupled magneto-electro-mechanical systems 磁-电-机械耦合系统的周动力学分析方法

IF 5.7 1区工程技术 Q1 ENGINEERING, MULTIDISCIPLINARY

International Journal of Engineering Science

Pub Date : 2025-12-01 Epub Date: 2025-09-29 DOI: 10.1016/j.ijengsci.2025.104391

Anasuyakumari Maram, Subrata Mondal, Sudarshan Dhua

A non-ordinary state-based peridynamic model(NOSBPD) is presented for linear piezoelectromagnetic material(PEM). The corresponding material model is developed by establishing the connection between the classical theory of piezoelectromagnetics and the newly proposed peridynamic framework. The variational approach and Hamiltonian principle are utilised to establish the equation of motion. This investigation shows the effectiveness of the proposed model to handle piezoelectromagnetic material. It is also shown that the considered stabilisation method effectively reduces the instabilities of NOSBPD. The dynamic behaviour of piezoelectromagnetic material in the proposed framework is investigated. The dispersion relations for stabilised versions of NOSBPD in one and two dimensions are established analytically for PEM. The graphs illustrate the influence of

δ

and different nonlocality functions on frequency, phase velocity, and group velocity. Also, the significant impact of critical coupling parameters on frequency is studied using graphical demonstration. Piezoelectromagnetic materials are used in a wide range of applications to constitute transducers such as actuators and sensors. Gaining insight into their wave and vibrational properties is indispensable for the advancement of reliable and optimised devices.

提出了线性压电材料（PEM）的非普通状态周动力学模型（NOSBPD）。通过建立经典压电理论与新提出的周动力框架之间的联系，建立了相应的材料模型。利用变分法和哈密顿原理建立了运动方程。研究结果表明，该模型对处理压电材料是有效的。研究还表明，所考虑的稳定方法可以有效地降低NOSBPD的不稳定性。研究了压电材料在该框架中的动态行为。对质子交换膜，建立了稳定型NOSBPD在一维和二维上的色散关系。图中显示了δ和不同的非局域函数对频率、相速度和群速度的影响。通过图形演示，研究了关键耦合参数对频率的显著影响。压电材料被广泛应用于构成传感器，如执行器和传感器。深入了解它们的波动和振动特性对于可靠和优化设备的进步是必不可少的。

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引用次数: 0

Tug-of-war between liquids and membranes 液体和膜之间的拔河

IF 5.7 1区工程技术 Q1 ENGINEERING, MULTIDISCIPLINARY

International Journal of Engineering Science

Pub Date : 2025-12-01 Epub Date: 2025-10-08 DOI: 10.1016/j.ijengsci.2025.104395

Weiting Chen, Quanzi Yuan

Predicting the deformation behavior of an initially stressed membrane subjected to liquid self-weight is nontrivial. Experimental observation indicates that in the tug-of-war competition between liquids and membranes, which side will prevail does not depend on the liquid volume. However, the existing models cannot explain this counterintuitive phenomenon. With the aim of understanding the underlying mechanics behind those unexpected features, we propose a theoretical model for deriving the configuration of membrane–liquid interactions. The analytical solutions for one-dimensional and two-dimensional axisymmetric membrane deflections are derived by combining the linear membrane theory and configuration-dependent loading. These solutions yield quantitative predictions for the three types of configuration that are in excellent agreement with the experiments. Remarkably, we find that a dimensionless parameter concerning the liquid density, the size of the system, and the membrane tension controls the intensity of the membrane–liquid competition. Our model opens up a new perspective for studying fluid–structure interaction systems.

预测初始应力膜在液体自重作用下的变形行为是非常重要的。实验观察表明，在液体与膜的拉锯战中，哪一方获胜并不取决于液体的体积。然而，现有的模型无法解释这种违反直觉的现象。为了理解这些意想不到的特征背后的潜在力学，我们提出了一个理论模型来推导膜-液体相互作用的配置。将线性膜理论与构型相关载荷相结合，导出了一维和二维轴对称膜挠度的解析解。这些解决方案产生了与实验非常一致的三种构型的定量预测。值得注意的是，我们发现一个关于液体密度、系统大小和膜张力的无量纲参数控制着膜-液竞争的强度。该模型为研究流固耦合系统开辟了一个新的视角。

引用次数: 0

Analytical study to control phase gradient in elastic meta-interface for wave mode conversions 波型转换弹性元界面中相位梯度控制的解析研究

IF 5.7 1区工程技术 Q1 ENGINEERING, MULTIDISCIPLINARY

International Journal of Engineering Science

Pub Date : 2025-12-01 Epub Date: 2025-09-23 DOI: 10.1016/j.ijengsci.2025.104388

Mohammad Daud, Jongmin Shim

We present an analytical and design framework for achieving efficient elastic wave mode conversion across meta-interfaces governed by Generalized Snell’s Law (GSL), which prescribes wave motion based on a spatial phase gradient along the interface. In contrast to conventional optimization-based approaches, our method provides clear physical insight into the mechanism of pressure-to-shear wave conversion through a simplified one-dimensional axial wave model with the transfer matrix approach. This model yields analytical expressions for geometric conditions and identifies the relevant design parameter space. Based on this framework, we propose a compact chiral-pattern subunit with a frequency-scalable geometry, enabling straightforward implementation across a range of wave conditions. Full-scale numerical simulations confirm that the resulting meta-interface achieves strong mode conversion performance and accurately reproduces key phenomena including transmitted angles. Additionally, we demonstrate symmetric transmission by introducing mirrored phase gradients, further validating the flexibility of the GSL-based design. While the conversion efficiency is constrained by angular limits inherent to the material’s Poisson ratio, the framework provides a foundation for future improvements. This work bridges analytical modeling and practical design, offering an interpretable and scalable approach to engineered wave manipulation.

我们提出了一个分析和设计框架，用于实现由广义斯涅尔定律（GSL）控制的跨元界面的有效弹性波模式转换，该定律规定了基于沿界面的空间相位梯度的波运动。与传统的基于优化的方法相比，我们的方法通过简化一维轴波模型和传递矩阵方法，对压力-剪切波转换机制提供了清晰的物理洞察。该模型给出了几何条件的解析表达式，并确定了相应的设计参数空间。基于这个框架，我们提出了一个紧凑的手性模式子单元，具有频率可扩展的几何形状，可以在一系列波浪条件下直接实现。全尺寸数值模拟证实，所得到的元界面实现了较强的模式转换性能，并准确地再现了包括透射角在内的关键现象。此外，我们通过引入镜像相位梯度来演示对称传输，进一步验证了基于gsl设计的灵活性。虽然转换效率受到材料泊松比固有的角度限制的限制，但该框架为未来的改进提供了基础。这项工作连接了分析建模和实际设计，为工程波浪操纵提供了一种可解释和可扩展的方法。

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引用次数: 0