Engineering Structures最新文献_第2页

Experimental and numerical study of a novel low-frequency tuned mass damper-inerter

IF 5.6 1区工程技术

Engineering Structures Pub Date : 2025-03-04 DOI: 10.1016/j.engstruct.2025.119980

Bo Wang, Fuyou Xu, Mingjie Zhang

{"title":"Experimental and numerical study of a novel low-frequency tuned mass damper-inerter","authors":"Bo Wang, Fuyou Xu, Mingjie Zhang","doi":"10.1016/j.engstruct.2025.119980","DOIUrl":"10.1016/j.engstruct.2025.119980","url":null,"abstract":"<div><div>A novel low-frequency tuned mass damper-inerter (LF-TMDI) with a rotor is proposed to significantly reduce the initial length and static stretching of the spring. The required installation space is thus reduced, allowing it to accommodate low-frequency vibration control. The proposed LF-TMDI can be installed inside a steel box girder (with internal installation space of 3 ∼ 4 m), effectively controlling low-frequency vibrations (e.g., 0.2 Hz) for long-span bridges. A physical LF-TMDI device is fabricated, and the experimental results indicate that the damping of the device can be characterized by Coulomb damping or equivalent viscous damping. The equations of motion for the coupled system of the LF-TMDI device and the controlled structure are derived. Vibration tests confirm that the fabricated LF-TMDI device can effectively control the vibration of a low-frequency (0.5 Hz) oscillator. Numerical parametric analyses show that the TMDI control efficiency remains stable within a deviation range of ( ± 5 ‰) optimal damping ratio and ( ± 1 %) optimal frequency ratio. In practical engineering, increasing the mass ratio between the LF-TMDI mass block and the main structure, and selecting an appropriate mass ratio between the equivalent mass provided by the rotor and the TMDI mass block, are effective ways to improve the performance of the LF-TMDI. Finally, the optimal stiffness and damping parameters of the LF-TMDI for free vibration control under common conditions are provided through similar parametric analysis.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"331 ","pages":"Article 119980"},"PeriodicalIF":5.6,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Hysteretic behavior of resilient hinged wall enhanced with FRP bars

IF 5.6 1区工程技术

Engineering Structures Pub Date : 2025-03-04 DOI: 10.1016/j.engstruct.2025.119969

Yan Zhang , Longhe Xu , Xingsi Xie , Ge Zhang

{"title":"Hysteretic behavior of resilient hinged wall enhanced with FRP bars","authors":"Yan Zhang , Longhe Xu , Xingsi Xie , Ge Zhang","doi":"10.1016/j.engstruct.2025.119969","DOIUrl":"10.1016/j.engstruct.2025.119969","url":null,"abstract":"<div><div>To further improve the seismic resilience of resilient hinged walls (RHWs), in this study, an RHW is enhanced with fiber reinforced polymer bars (FRP bars). In the resulting RHW with FRP bars (RHW-FRP), two resilient hinge devices are symmetrically installed in the corners, and steel bars and FRP bars are installed in a hybrid arrangement in both the wall boundary elements and the middle wallboard. The analysis results indicate that the RHW-FRP exhibits less residual drift and a higher bearing capacity than the RHW. The hybrid layout between the FRP bars and steel bars in both the boundary elements and the middle wallboard of the RHW-FRP is recommended to achieve the optimal enhancement of the seismic resilience of the wall while ensuring economic viability. With this hybrid layout, the bearing capacity of the RHW-FRP can be improved to the same level as that of a conventional wall of the same size, and the residual drift ratio of the wall can be further controlled to about 0.42 % when the wall drift ratio reaches 3 %. Increasing the number of FRP bars in the wall boundary elements is found to have less influence on the hysteretic behavior of the wall, whereas increasing the number of FRP bars in the middle wallboard can significantly increase the wall bearing capacity. With the increase of the axial compression ratio of the wall, the RHW-FRP will exhibit a higher bearing capacity but more residual drift. Moreover, while increasing the strength of the concrete used in the wallboard will improve the wall bearing capacity at a small drift, the bearing capacity may degrade at a larger drift due to the early crush of the concrete.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"331 ","pages":"Article 119969"},"PeriodicalIF":5.6,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Experimental and theoretical study of thin-covered composite dowels considering multiple load conditions

IF 5.6 1区工程技术

Engineering Structures Pub Date : 2025-03-04 DOI: 10.1016/j.engstruct.2025.119979

Zhihua Xiong , Jiaqi Li , Xulin Mou , Tiankuo Wang , Abedulgader Baktheer , Markus Feldmann

{"title":"Experimental and theoretical study of thin-covered composite dowels considering multiple load conditions","authors":"Zhihua Xiong , Jiaqi Li , Xulin Mou , Tiankuo Wang , Abedulgader Baktheer , Markus Feldmann","doi":"10.1016/j.engstruct.2025.119979","DOIUrl":"10.1016/j.engstruct.2025.119979","url":null,"abstract":"<div><div>With the widespread application of composite structures in the fields of building and bridge constructions, thin-covered composite dowels are increasingly adopted in various engineering scenarios. This paper presents a design methodology for thin-covered composite dowels, supported by both experimental and theoretical investigations. In the experiment, a novel test rig and specimens are designed to facilitate tensile-shear coupling loading. The study identifies a new failure mode: Restricted Cone Failure (RCF) in thin-covered composite dowels under tensile-shear coupling load, which distinct from conventional composite dowels. This RCF mode is attributed to the thin thickness of the side concrete cover, which restricts the development of the failure cone in the thickness direction. Additionally, a parametric analysis is conducted to evaluate the effects of key factors—such as steel dowel thickness, effective embedment depth, and the tensile strength of steel fiber reinforced concrete—on the bearing capacity and ductility of thin-covered composite dowels. Based on the theoretical findings, comprehensive tensile, shear, and tensile-shear coupling capacity models along with an engineering design model are developed to aid in the practical application of thin-covered composite dowels.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"331 ","pages":"Article 119979"},"PeriodicalIF":5.6,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Influence of sand cushion on rockfall-impact resistance of RC sheds

IF 5.6 1区工程技术

Engineering Structures Pub Date : 2025-03-04 DOI: 10.1016/j.engstruct.2025.119992

R.W. Li , S.B. Meng , Y. Chen , H. Wu , Y.D. Zhou

{"title":"Influence of sand cushion on rockfall-impact resistance of RC sheds","authors":"R.W. Li , S.B. Meng , Y. Chen , H. Wu , Y.D. Zhou","doi":"10.1016/j.engstruct.2025.119992","DOIUrl":"10.1016/j.engstruct.2025.119992","url":null,"abstract":"<div><div>Reinforced concrete (RC) sheds with sand cushions laying on the top are commonly adopted to resist rockfall impacts. To improve the rockfall-impact resistance of RC shed with sand cushion, this study investigated the buffering performance of sand cushion and examined the effect of sand cushion on the dynamic behaviors of RC shed. Firstly, a series of impact tests on sand cushion were conducted to analyze the influence of cushion thickness and falling height of rockfall on the penetration depth into the cushion, impact force and impact duration, as well as the development of vertical and horizontal stresses inside the cushion. Then, a finite element-discrete element coupling model was established to consider the particle interaction of sand cushion under rockfall impacts and impact behaviors of RC shed. Finally, based on the validated numerical analysis method, the effect of sand cushion on the dynamic responses and damage of prototype RC shed subjected to the impact of rockfall was simulated and evaluated. The results showed that: (i) with the increase of cushion thickness, the peak impact force was reduced, but the penetration depth and duration increased; as the falling height elevated, the impact force and penetration depth increased while the duration was shortened; (ii) sand cushion had excellent buffering performance to attenuate vertical and horizontal stresses inside the cushion; (iii) stress diffusion angle formed in the sand cushion can enlarge the load-bearing area at the bottom of the cushion, and the buffering performance of sand cushion can be improved through increasing the stress diffusion angle; (iv) compared with the non-cushion one, the rockfall-impact resistance of RC shed was effectively improved by the sand cushion through reducing impact force, penetration depth, dynamic bending moment and shear force of the shed roof, as well as transforming brittle punching-shear failure of the shed roof into flexural failure.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"331 ","pages":"Article 119992"},"PeriodicalIF":5.6,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Performance evaluation of a lever-assisted optimized tuned mass damper inerter in mitigating edgewise vibration of wind turbine blade

IF 5.6 1区工程技术

Engineering Structures Pub Date : 2025-03-04 DOI: 10.1016/j.engstruct.2025.119954

Vishal D. Sonkusare, Kamal Krishna Bera

{"title":"Performance evaluation of a lever-assisted optimized tuned mass damper inerter in mitigating edgewise vibration of wind turbine blade","authors":"Vishal D. Sonkusare, Kamal Krishna Bera","doi":"10.1016/j.engstruct.2025.119954","DOIUrl":"10.1016/j.engstruct.2025.119954","url":null,"abstract":"<div><div>A Lever-assisted Tuned Mass Damper Inerter (LTMDI), comprising a lever mechanism with a fulcrum and a spanning inerter, coupled with a Tuned Mass Damper (TMD), is introduced to mitigate the edgewise vibration of wind turbine blades. The equations of motion for the coupled blade-LTMDI-tower system are derived using the Euler–Lagrangian approach. The turbulent aerodynamic loads on the blade are calculated using the modified Blade Element Momentum theory. Closed-form expressions for optimal tuning frequency and damping ratio of LTMDI are derived from a simplified 2-DOF blade-LTMDI model using the classical fixed-point theory. These expressions also verify the corresponding formulas for blade with TMDI and TMD reported in the existing literature. Numerical studies are conducted using the National Renewable Energy Laboratory (NREL) 5-MW horizontal axis wind turbine. A comprehensive analysis in both time and frequency domains is performed to evaluate the control effectiveness of LTMDI for both the 2-DOF and full wind turbine models, with results compared to those obtained using TMDI and TMD. Results reveal that TMD is the most effective at reducing blade response, while TMDI excels in minimizing the stroke length of the mass block, and LTMDI performs between these two extremes. To systematically compare the overall performance of these devices, a normalized performance index is proposed, which incorporates peak, RMS, and peak-to-peak displacements of both blade tip and mass block. It is observed that LTMDI effectively serves as a trade-off between TMD and TMDI, providing a consistent and uniform performance regardless of whether the focus is on reducing blade response or minimizing the stroke length of the mass block. Therefore, LTMDI emerges as the optimal choice, offering a comprehensive solution that effectively addresses both blade and mass block responses, and demonstrating significant potential for application in wind turbine blades.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"331 ","pages":"Article 119954"},"PeriodicalIF":5.6,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Buckling behavior of built-up thin-walled I-beams with trapezoidal flanged cores

IF 5.6 1区工程技术

Engineering Structures Pub Date : 2025-03-04 DOI: 10.1016/j.engstruct.2025.120004

Michał Plust, Piotr Paczos, Piotr Kędzia

引用次数: 0

Long-term behavior of reduced length FRP tendons in post-tensioned steel beam-column connections

IF 5.6 1区工程技术

Engineering Structures Pub Date : 2025-03-04 DOI: 10.1016/j.engstruct.2025.119965

Mohamed F.M. Fahmy , Ahmed Samy B.Z. Hassan , Shehata E. Abdel Raheem , Mohamed Abdel-Basset Abdo , Redhwan M. Algobahi

{"title":"Long-term behavior of reduced length FRP tendons in post-tensioned steel beam-column connections","authors":"Mohamed F.M. Fahmy , Ahmed Samy B.Z. Hassan , Shehata E. Abdel Raheem , Mohamed Abdel-Basset Abdo , Redhwan M. Algobahi","doi":"10.1016/j.engstruct.2025.119965","DOIUrl":"10.1016/j.engstruct.2025.119965","url":null,"abstract":"<div><div>The long-term behavior of different fiber reinforced polymer (FRP) tendons has been investigated experimentally up to 2000 h. Seven half-scaled exterior post-tensioned (PT) beam-column connection subassemblies, containing reduced length basalt fiber reinforced polymer (BFRP), carbon fiber reinforced polymer (CFRP), and glass fiber reinforced polymer (GFRP) tendons, were tested. To simulate the actual loading conditions in real buildings, an equivalent gravity load was applied to each connection subassembly. Also, to investigate the PT force level effect, three PT force levels, up to 50 %, were applied to 10 mm BFRP tendons, while two PT force levels were applied to 10 mm CFRP tendons. Besides, a 20 % PT force level was applied to 10 mm GFRP tendons. In addition, to study the effect of tendons’ diameter on the long-term behavior, PT connection subassembly containing 12 mm diameter BFRP tendons with 30 % PT force level was tested. The maximum PT force losses were almost 6.1, 5.8, 4.0 % for BFRP, CFRP, and GFRP, respectively. Finally, according to the experimental test results, unified relaxation equations were proposed to predict the amount of PT force loss. Consequently, the predicted PT force losses for one-million-hour period were approximately 15.3 and 12.2 % for BFRP and CFRP tendons, respectively.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"331 ","pages":"Article 119965"},"PeriodicalIF":5.6,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Crushing behavior of biomimetic hierarchical multi-cell thin-walled tubes under multi-angle loading

IF 5.6 1区工程技术

Engineering Structures Pub Date : 2025-03-04 DOI: 10.1016/j.engstruct.2025.119996

Chao Gong , Chenxi Meng , Qi Chong , Lei Chen , Yage Guo

{"title":"Crushing behavior of biomimetic hierarchical multi-cell thin-walled tubes under multi-angle loading","authors":"Chao Gong , Chenxi Meng , Qi Chong , Lei Chen , Yage Guo","doi":"10.1016/j.engstruct.2025.119996","DOIUrl":"10.1016/j.engstruct.2025.119996","url":null,"abstract":"<div><div>This paper proposes a set of biomimetic hierarchical multi-cell thin-walled structures (BHM). The internal structure of the proposed BHM tubes is constructed based on the micro-structure of bamboo and traditional multi-cell thin-walled structures (TMT). The crashworthiness performance of the proposed structures with different cross-sectional configurations under multi-angle loads was numerically studied. The anti-collision performance of BHM and TMT under multi-angle crushing loads was comparatively studied through finite element simulation. In addition, the TOPSIS method was used to select the optimal cross-sectional configuration of the biomimetic thin-walled tube. The results show that compared with TMT, BHM exhibits excellent crashworthiness under small-angle collisions, and this advantage begins to decline as the collision angle increases. Among different types of BHM, the hexagonal BHM and the balanced configuration of BHM can effectively improve the energy absorption capacity and load stability of the structure, and quadrilateral BHM provides a reference for reducing the peak crushing force. The optimal cross-sectional configuration obtained by the TOPSIS method is the hexagonal bio-hierarchical multi-walled tube with a balanced configuration. Finally, a comparative analysis with other hierarchical multi-cell tubes reported in the literature confirms that the crashworthiness performance of BHM exceeds existing designs. Theoretical derivation of the mean crushing force was conducted for the proposed tubes, and the theoretical predictions of MCF are in good agreement with the numerical results. The results of this study provide effective guidance for using the biomimetic method with a bamboo-like micro cross-sectional morphology to design multi-cell energy absorbers with high energy absorption efficiency.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"331 ","pages":"Article 119996"},"PeriodicalIF":5.6,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Probabilistic multi-hazard risk assessment of high-rise buildings subjected to concurrent earthquakes and strong winds

IF 5.6 1区工程技术

Engineering Structures Pub Date : 2025-03-03 DOI: 10.1016/j.engstruct.2025.119972

Qian-Qian Yu , Ling-Han Liu , Xiang-Lin Gu , Yao-Yao Zhang

{"title":"Probabilistic multi-hazard risk assessment of high-rise buildings subjected to concurrent earthquakes and strong winds","authors":"Qian-Qian Yu , Ling-Han Liu , Xiang-Lin Gu , Yao-Yao Zhang","doi":"10.1016/j.engstruct.2025.119972","DOIUrl":"10.1016/j.engstruct.2025.119972","url":null,"abstract":"<div><div>This paper presents a multi-hazard risk analysis of high-rise buildings exposed to earthquakes and strong winds. A concurrent hazard database was first collected, consisting of 35,687 sets of concurrent hazards from 1901 to 2020, with earthquakes greater than M 4.0 and wind speeds exceeding 10 m/s. The probability of simultaneous occurrence of earthquakes and strong winds was theoretically derived and verified through Monte Carlo simulation and statistical result. Afterward, numerical simulation was performed on two high-rise buildings, with special focus on the fragility of the structures exposed to both individual and multiple hazards. The maximum top displacement of the structure under multiple hazards exceeded 0.9 %−24.6 % of the superposition of responses under individual hazards. The annual failure probability of the structure was analyzed through convolution of the disaster risk function and the structure fragility function. It was indicated that the annual failure probability under concurrent hazard conditions was 1.12 −2.05 times of that under individual hazard conditions in the damaged state of IDR (Inter-story Drift Ratio)> 1.5 %.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"331 ","pages":"Article 119972"},"PeriodicalIF":5.6,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Precast concrete connections for alleviating reinforcement congestion: A state-of-the-art review

IF 5.6 1区工程技术

Engineering Structures Pub Date : 2025-03-03 DOI: 10.1016/j.engstruct.2025.119985

Xin Nie, Da Huang, Liangdong Zhuang, Jiansheng Fan, Niankai Deng

{"title":"Precast concrete connections for alleviating reinforcement congestion: A state-of-the-art review","authors":"Xin Nie, Da Huang, Liangdong Zhuang, Jiansheng Fan, Niankai Deng","doi":"10.1016/j.engstruct.2025.119985","DOIUrl":"10.1016/j.engstruct.2025.119985","url":null,"abstract":"<div><div>In prefabricated structures, densely distributed stirrups and splicing of longitudinal reinforcement extending from precast components can result in rebar congestion in precast concrete connections, obstructing the assembly of precast components and proper concrete compaction. To address these issues, five types of joint details less susceptible to reinforcement congestion have been thoroughly reviewed. Mechanical connectors, as a substitute for lap splices of protruding rebars, are incorporated in dry and hybrid connections, which exhibit semi-rigid behavior under seismic loading. Notched connections, typified by evenly spaced notches at the side surfaces of precast components, employ post-installed connecting bars to replace projecting reinforcement. Design guides for notch geometry and anchorage length of connecting bars inserted in notches were proposed based on pull-out test results. Precast rocking systems with self-centering capability can be established by unbonded post-tensioning, which clamps structural components together without the necessity for rebar splicing. Energy dissipation is achieved by metallic, viscoelastic, or friction dampers. Furthermore, the ultra-high bond strength of reinforcing bars anchored in UHPC allows for short lap-spliced joints, while employing ECC as grouting materials enhances joint confinement and shear strength, enabling a reduction or total elimination of stirrups in precast concrete connections. Reinforcement congestion can be also relieved by separating beam-to-column connections into beam-to-beam and column-to-column joints, which effectively reduces the amount of reinforcement intersecting in the joint core.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"331 ","pages":"Article 119985"},"PeriodicalIF":5.6,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143549990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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