Journal of The Mechanics and Physics of Solids最新文献

{"title":"Effective mechanical response of biomimetic staggered composites: Closed-form estimates via a micromechanical variational formulation","authors":"Pierfrancesco Gaziano ,&nbsp;Lorenzo Zoboli ,&nbsp;Elisabetta Monaldo ,&nbsp;Giuseppe Vairo","doi":"10.1016/j.jmps.2025.106137","DOIUrl":"10.1016/j.jmps.2025.106137","url":null,"abstract":"<div><div>Bio-inspired composite materials with staggered microstructures exhibit superior mechanical properties compared to traditional composites, paving the way for the development of advanced functional materials. The existing analytical models mainly address the macroscale constitutive response along the staggering direction using plane strain or plane stress assumptions. Consequently, a significant gap remains in the characterization of the equivalent material response in triaxial loading scenarios. This study presents a micromechanical variational formulation to derive an analytical and comprehensive characterization of the anisotropic homogenized behavior of biomimetic staggered composites. The microscale equilibrium problem, tailored to a suitable representative volume element, is tackled by applying stationary conditions to the total potential energy functional, evaluated over a class of quasi-compatible strain fields that capture the dominant microscale kinematics. A linearization technique leads to closed-form expressions that fully characterize the macroscale stiffness tensor of the material. Through a parametric case study, the obtained analytical results are compared with finite element simulations and theoretical solutions and bounds. The results confirm the validity of the proposed formulation, demonstrating the consistency and accuracy of the obtained analytical estimates.</div></div>","PeriodicalId":17331,"journal":{"name":"Journal of The Mechanics and Physics of Solids","volume":"200 ","pages":"Article 106137"},"PeriodicalIF":5.0,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143829238","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}

{"title":"Probing Fracture Mechanics of Graphene through Heterocrack Propagation in a Moiré Superlattice","authors":"Yuan Hou ,&nbsp;Jingzhuo Zhou ,&nbsp;Zezhou He ,&nbsp;Shuai Zhang ,&nbsp;Qunyang Li ,&nbsp;Huajian Gao ,&nbsp;Yang Lu","doi":"10.1016/j.jmps.2025.106151","DOIUrl":"10.1016/j.jmps.2025.106151","url":null,"abstract":"<div><div>Understanding the fracture properties of two-dimensional (2D) materials is essential for enhancing their mechanical performance and extending the service life of 2D-based devices. A major challenge lies in examining stress singularities near crack tips at the nanoscale. In this study, we show that we can obtain fracture toughness of monolayer graphene by investigating the propagation of heterocrack in twisted graphene layers. We developed an in situ mechanical measurement to monitor the heterocrack propagation under electron microscopy. The cracks propagated and deflected along the twisted graphene-graphene interfaces, accompanied by periodic stress fluctuations and distorted moiré superlattices. By further leveraging molecular dynamics simulations, we developed a moiré strain analysis method to track strain distributions during heterocrack propagation in the moiré superlattice. The fracture toughness can be measured through the strain fields at the crack tip. Moreover, we examined the effect of the moiré potential on the heterocrack propagation behaviors and proposed an equivalent stress intensity factor to evaluate the fracture properties of graphene under varying twist angles. This work provides key insights into the fracture mechanics of 2D materials, and also offers a foundation for assessing the reliability and mechanical stability of 2D-material-based nanodevices.</div></div>","PeriodicalId":17331,"journal":{"name":"Journal of The Mechanics and Physics of Solids","volume":"200 ","pages":"Article 106151"},"PeriodicalIF":5.0,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143851686","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}

{"title":"Force-field-induced energy-based design method for arbitrary prescribed modes in elastic metamaterials","authors":"Zhiwen Ren ,&nbsp;Hao-Wen Dong ,&nbsp;Mingji Chen ,&nbsp;Haiou Yang ,&nbsp;Yue-Sheng Wang ,&nbsp;Li Cheng ,&nbsp;Daining Fang","doi":"10.1016/j.jmps.2025.106144","DOIUrl":"10.1016/j.jmps.2025.106144","url":null,"abstract":"<div><div>Elastic metamaterials possess flexible regulatory capabilities of elastodynamic field information and energy through engineering and tailoring wave amplitudes, phase, and polarization vectors. However, due to the lack of general wave quantities and dynamic mode characterization methods, it is difficult to describe and design customized elastic dispersions with prescribed eigenmodes of interest, especially under large wave vectors or high frequencies. To tackle this challenge, we propose a systematic design method based on force-field-induced energy to inversely customize arbitrary prescribed eigenmodes at required frequencies for both small and large wave vectors. We build up a dynamic mode characterization theory based on energy, which contributes to portraying eigenmode response behavior under external excitations. It theoretically reveals the distribution features of the energy, induced by external excitations, in wave vector-frequency (<span><math><mrow><mi>k</mi><mtext>-</mtext><mi>ω</mi></mrow></math></span>) domain for the solid media. A systematic inverse-design method, using responsive energy maximization, is proposed to tailor-make eigenmodes and dispersions under arbitrarily prescribed <span><math><mrow><mi>k</mi><mtext>-</mtext><mi>ω</mi></mrow></math></span> conditions. Then, a series of periodic porous structures are optimized to support orthotropic/anisotropic longitudinal, transversal and rotational modes at different <span><math><mrow><mi>k</mi><mtext>-</mtext><mi>ω</mi></mrow></math></span> points, alongside customized dispersion. Meanwhile, an inverse strategy fusing longitudinal and transversal modes is forged and used to realize broadband fluid-like mode in porous microstructure with an effective refractive index, in which a strongly suppressed transversal mode in the extremely low-frequency region of the dispersion and a single broadband longitudinal mode are supported. In addition, through inversely designing local vibration modes at three <span><math><mrow><mi>k</mi><mtext>-</mtext><mi>ω</mi></mrow></math></span> points simultaneously, a dispersion passband supporting negative group velocity is generated within an expected frequency range. Meanwhile, entire dispersion curves satisfying the prescribed <span><math><mrow><mi>k</mi><mtext>-</mtext><mi>ω</mi></mrow></math></span> relationship and supporting prescribed modes are customized. The wave behaviors of the optimized metamaterials are elucidated by phonon-band-structure experiments as well as numerical simulations. The established approach provides a universal design paradigm of wave modes that promises to pave the route for engineering extreme dispersion and functionalities.</div></div>","PeriodicalId":17331,"journal":{"name":"Journal of The Mechanics and Physics of Solids","volume":"200 ","pages":"Article 106144"},"PeriodicalIF":5.0,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143843818","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}

{"title":"Slow dynamic nonlinear elasticity during and after conditioning, a unified theory and a lock-in probe","authors":"John Y. Yoritomo ,&nbsp;Richard L. Weaver","doi":"10.1016/j.jmps.2025.106149","DOIUrl":"10.1016/j.jmps.2025.106149","url":null,"abstract":"<div><div>Of the non-classical nonlinear elastic phenomena, slow dynamics (SD) has received particular attention due to recent modeling efforts and experiments in new systems. SD is characterized by a loss of stiffness after a minor conditioning strain, followed by a slow recovery back towards the original stiffness. It is observed in many imperfectly consolidated granular materials (e.g., rocks and concrete) and unconsolidated systems (e.g., bead packs). Here we posit a simple unified phenomenological model capable of seamlessly describing modulus evolution for SD materials during steady-state conditioning, during conditioning ringdown, and during recovery. It envisions a distribution of breaking and healing bonds, with healing rates governed by the usual spectrum of relaxation times. Well after the end of conditioning, the model recovers the characteristic logarithmic-in-time relaxation. For times during conditioning ringdown, when recovery has initiated but conditioning has not fully ceased, the model predicts deviations from log(t) and a dependence on the ringdown rate. We compare these model predictions with SD measurements on four different systems. To perform the measurements, an ultrasonic digital lock-in (DLI) probe is developed. The advantages of DLI over other techniques to measure SD are a sufficiently high time resolution and an insensitivity to noise from conditioning. We find good agreement between theory and experiment. The model in conjunction with DLI also allows for estimates of the minimum relaxation time. Our measurements indicate that the minimum relaxation time is material dependent.</div></div>","PeriodicalId":17331,"journal":{"name":"Journal of The Mechanics and Physics of Solids","volume":"200 ","pages":"Article 106149"},"PeriodicalIF":5.0,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143843816","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}

{"title":"On the elastic problem of representative volume element for multiphase thin films","authors":"Ahmad Ahmad ,&nbsp;Kyle Starkey ,&nbsp;Khaled SharafEldin ,&nbsp;Anter El-Azab","doi":"10.1016/j.jmps.2025.106142","DOIUrl":"10.1016/j.jmps.2025.106142","url":null,"abstract":"<div><div>Multiphase thin films exhibit unique physical functionalities stemming from their dimensions and interactions among phases. In these materials, elasticity plays an important role both in their growth and physical performance. An outstanding problem in this regard is the elastic formulation of representative volume element (RVE) of thin film systems. As thin films RVEs lack translation invariance in the direction perpendicular to the film free surface, the boundary value problem of the RVE involves integral kinematic boundary constraints that must be satisfied together with the governing elastic boundary value problem. These constraints were developed here as a part of a homogenization scheme designed to deliver the elastic solution in a heterogeneous thin film, with both eigenstrain and modulus mismatch within the phases. We formulated this problem together with an iterative solution scheme based on Fast Fourier Transform with an augmented Lagrangian fixed-point iteration algorithm. The numerical solution was benchmarked with the analytical solution of the famous Eshelby problem for the case of homogeneous and inhomogeneous cylindrical inclusions. Diffuse interface and discrete Green's operator methods were tested to investigate the attenuation of Gibbs oscillations at interfaces. Examples of thin film morphologies generated using kinetic Monte Carlo simulations at different growth conditions were used as microstructure input to test the current approach. We show that the elastic energy tends to be concentrated near the pillar/matrix interface. This approach is expected to enable the on-the-fly coupling of elasticity solution with thin film growth models to account for the elastic strain effects on diffusion, bonding, and interfacial energies.</div></div>","PeriodicalId":17331,"journal":{"name":"Journal of The Mechanics and Physics of Solids","volume":"200 ","pages":"Article 106142"},"PeriodicalIF":5.0,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143843819","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}

{"title":"Constrained mixture models of growth and remodelling in an infarct left ventricle: A modelling study","authors":"Debao Guan ,&nbsp;Xiaoyu Luo ,&nbsp;Hao Gao","doi":"10.1016/j.jmps.2025.106121","DOIUrl":"10.1016/j.jmps.2025.106121","url":null,"abstract":"<div><div>Myocardial infarction (MI), characterized by the death of myocytes in the myocardium, leads to high morbidity and mortality rates worldwide. The persistent imbalance of biomechanical stress and strain within the myocardium is a critical factor contributing to adverse growth and remodelling (G&amp;R) following MI, such as wall thinning and chamber dilation. This study investigates the structural and functional adaptations of a left ventricle (LV) after MI through the application of a constrained mixture model of G&amp;R. We further examine the effects of fibre dispersion on LV pump performance using this G&amp;R model. Our model successfully reproduces key characteristics of post-MI G&amp;R, including scar thinning, LV cavity dilation and wall stiffening. Pure myofibre G&amp;R after scar maturation could lead to excessive LV dilation with slightly reduced stroke volume. In contrast, pure collagen G&amp;R would result in a significantly reduced stroke volume that will not meet the blood demand of a patient. A moderate increase in fibre dispersion could prevent significant LV dilation and maintain LV stroke volume, which might be beneficial in preserving normal LV pump function. Whereas excessive dispersion could severely impair active contractility, leading to a much-reduced stroke volume, and ultimately progressing towards heart failure. Future investigations should incorporate the complex interplays between mechanical triggers, biochemical environment and pathological pathways using this constrained mixture theory framework. This approach has the potential to enhance our understanding of cardiac tissue G&amp;R following myocardial infarction, predict LV pump failure due to adverse remodelling, and aid in the assessment of therapeutic strategies in the future.</div></div>","PeriodicalId":17331,"journal":{"name":"Journal of The Mechanics and Physics of Solids","volume":"200 ","pages":"Article 106121"},"PeriodicalIF":5.0,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143834952","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}

{"title":"Polyurethane elastomer with stable mechanical performance during biodegradation: Material design and constitutive modeling","authors":"Zhuoran Yang ,&nbsp;Jiaxin Shi ,&nbsp;Yifeng Li ,&nbsp;Ziming Yan ,&nbsp;Jun Xu ,&nbsp;Zhanli Liu","doi":"10.1016/j.jmps.2025.106145","DOIUrl":"10.1016/j.jmps.2025.106145","url":null,"abstract":"<div><div>The growing demand for biodegradable elastomers necessitates innovative designs achieving controllable degradation rates while maintaining stable mechanical performance. This work presents a novel polyurethane elastomer (PUE) with dual degradation pathways, including selective degradation of soft and hard domain. This design offers enhanced control over mechanical performance, realizing only 15 % reduction in failure stretch at ∼50 % degradation and less than 2 % loss in initial modulus at ∼85 % degradation. Next, we propose a novel micro-mechanical model incorporating domain-specific degradation mechanisms to theoretically predict the degradation mechanical performance of PUE. A modified generalized series configuration captures domain interactions by linking free joint chains in soft domain with extensible hard segment clusters. Specially, degradation degree is defined as an internal variable characterizing the evolution of microscopic parameters, including Kuhn segments number, chain density, and cluster density. Thus, the macroscopic changes in modulus and failure stretch can be directly correlated to the microscopic degradation-induced chain scission, cluster breakage, and interactions like chain release and cluster detachment. The model successfully predicts the tensile behavior of PUE under selective degradation. Further theoretical analysis reveals that robust clusters play a pivotal role in maintaining mechanical stability and their continuously preserved structural integrity effectively minimizes modulus reduction caused by chain scission and cluster breakage. This work provides theoretical insights and a practical foundation for the rational design and application of biodegradable PUEs.</div></div>","PeriodicalId":17331,"journal":{"name":"Journal of The Mechanics and Physics of Solids","volume":"200 ","pages":"Article 106145"},"PeriodicalIF":5.0,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143835028","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}

{"title":"Coupling of low elastic modulus with porosity makes extreme low ice adhesion strength possible","authors":"Hongcheng Du ,&nbsp;Kun Li ,&nbsp;Jinhong Yang ,&nbsp;Pengfei Hao ,&nbsp;Xingshi Gu ,&nbsp;Xian Yi ,&nbsp;Zhiping Xu ,&nbsp;Cunjing Lv","doi":"10.1016/j.jmps.2025.106147","DOIUrl":"10.1016/j.jmps.2025.106147","url":null,"abstract":"<div><div>Anti-icing surfaces are vital for transportation and infrastructure. Low adhesion strength enables energy-efficient wind-driven or vibration-based ice-removal techniques beyond heating. A key challenge is to reduce the tangential adhesion strength of ice below 10 kPa, a goal hindered in practice by the high toughness of the ice-substrate interface. Even superhydrophobic materials with low surface energy struggle. Recent studies leverage low elastic moduli, lubricated surfaces, and minimal ice contact of porous substrates to reduce the adhesion strength. However, the rationale behind such an approach remains unclear, with no theories available for design purposes. In this study, we address this gap by establishing a solid mechanics framework based on fracture mechanics to model ice adhesion and inform anti-icing surface design. Here, we present an ice-solid interface fracture theory based on the Biot theory and a neo-Hookean framework, which accounts for substrate deformation and energy balance during ice debonding. Guided by this model, we optimized material properties of the substrate, including the porosity and pore size. Increasing porosity reduces the contact area and elastic modulus, while an optimized pore size prevents ice ingress and promotes interfacial cracking, lowering the interface toughness and energy cost of ice removal. The model prediction revises conventional scaling relations between the adhesion strength and the substrate modulus by modifying the exponent from 1/2 to 1, allowing the strength to reach even 0.1 kPa in theory. A durable, weather-resistant substrate with a tangential adhesion strength of 3 kPa is demonstrated in experiments.</div></div>","PeriodicalId":17331,"journal":{"name":"Journal of The Mechanics and Physics of Solids","volume":"200 ","pages":"Article 106147"},"PeriodicalIF":5.0,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143835029","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}

{"title":"A nonlinear toroidal shell model for surface morphologies and morphogenesis","authors":"Ting Wang ,&nbsp;Michel Potier-Ferry ,&nbsp;Fan Xu","doi":"10.1016/j.jmps.2025.106135","DOIUrl":"10.1016/j.jmps.2025.106135","url":null,"abstract":"<div><div>Biological tissues with core–shell structures usually exhibit non-uniform curvatures such as toroidal geometry presenting interesting features containing positive, zero, and negative Gaussian curvatures within one system, which give rise to intriguing instability patterns distinct from those observed on uniformly curved surfaces. Such varying curvatures would dramatically affect the growing morphogenesis. To understand the underlying morphoelastic mechanism and to quantitatively predict morphological instability patterns, we develop a nonlinear toroidal core–shell model and incorporate advanced numerical techniques for pattern prediction. Analytical solutions indicate that regions with positive Gaussian curvature (outer ring) require higher critical buckling stresses than those with negative Gaussian curvature (inner ring), with the critical threshold positively correlated to the key dimensionless parameters that are composed of curvature and stiffness of the system. Using the <em>Asymptotic Numerical Method</em> (ANM) as a robust path-following continuation approach, we continuously trace the post-buckling evolution and the associated wrinkling topography. We reveal that for donut-like toroidal core–shell structures, stripes initially form in the inner region with negative Gaussian curvature, and then evolve into a non-uniform hexagonal pattern in the post-buckling stage, while localized dimples may appear in core–shell tori with low stiffness. For cherry-like core–shell tori, the outer region with positive Gaussian curvature usually exhibits axisymmetric stripes or hexagonal patterns. A phase diagram on wrinkling topography at the critical buckling threshold is provided, in line with analytical predictions, offering fundamental insights into the complex interplay between curvature and material stiffness on multi-phase pattern selection in core–shell structures.</div></div>","PeriodicalId":17331,"journal":{"name":"Journal of The Mechanics and Physics of Solids","volume":"200 ","pages":"Article 106135"},"PeriodicalIF":5.0,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143816683","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}

{"title":"On a holistic variational formulation for material modeling including dissipative evolution","authors":"Philipp Junker ,&nbsp;Tobias Bode ,&nbsp;Klaus Hackl","doi":"10.1016/j.jmps.2025.106133","DOIUrl":"10.1016/j.jmps.2025.106133","url":null,"abstract":"<div><div>Based on Hamilton’s principle of stationary action, we present a holistic variational formulation for material modeling including dissipative evolution. To this end, we recall the definition of the action as path integral of the momentum vector. Reformulation of the action and inserting the 1<span><math><mi>st</mi></math></span> and 2<span><math><mi>nd</mi></math></span> Law of Thermodynamics yield an extended Hamilton functional. We show that the stationarity conditions yield well-known expressions as well as new conditions in an extended nested time domain. Introducing an asymptotic two-scale approach transforms the expressions in the nested time domain back to the physical time. Hereby, we receive usual differential equations, e.g., heat conductivity equation, diffusion equation, and Biot equation, and the constitutive laws for, e.g., temperature, entropy, and chemical potential, all from one holistic stationarity principle. Moreover, the formulation in the nested time domain produces additional, virtual conditions that naturally lead to the concept of dissipation distances. Due to its variational origin, our approach yields in a consistent manner a coupled space–time formulation.</div></div>","PeriodicalId":17331,"journal":{"name":"Journal of The Mechanics and Physics of Solids","volume":"200 ","pages":"Article 106133"},"PeriodicalIF":5.0,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143839097","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}