Marine Structures最新文献_第10页

Assessment of arresting performance of integral buckle arrestors for sandwich pipes using machine learning techniques 利用机器学习技术评估夹砂管道整体扣式阻火器的阻火性能

IF 3.9 2区工程技术

Marine Structures Pub Date : 2024-02-15 DOI: 10.1016/j.marstruc.2024.103599

Xipeng Wang , Chuangyi Wang , Lin Yuan , Zhi Ding

{"title":"Assessment of arresting performance of integral buckle arrestors for sandwich pipes using machine learning techniques","authors":"Xipeng Wang , Chuangyi Wang , Lin Yuan , Zhi Ding","doi":"10.1016/j.marstruc.2024.103599","DOIUrl":"https://doi.org/10.1016/j.marstruc.2024.103599","url":null,"abstract":"<div><p>Integral buckle arrestors are regarded as the most effective arresting devices and can be perfectly adapted to innovative sandwich pipes. In the present study, hyperbaric chamber tests were performed on reduced-scale sandwich pipe specimens equipped with integral arrestors, and the effect of interface bonding behaviour on the crossover pressure was examined. Then, numerical frameworks were proposed to replicate buckling propagating and crossing phenomena under hydrostatic pressure, with a strong consistency between measurements and predictions. A broad parametric analysis on the crossover pressure was implemented covering key material properties and geometries. After that, machine learning techniques were introduced and used for predictions of crossover pressure and arresting efficiency. Four algorithms, involving Random Forest, Multi-layer Perceptron, K-Nearest Neighbors, and Support Vector Machine, were established using a dataset comprising 248 cases with thirteen variables. Based upon an evaluation of standard statistical metrics, it is observed that RF and MLP exhibit superior prediction accuracy, whereas the prediction performance of KNN is the worst. The results show that the machine learning method provides relatively reliable predictions of crossover pressure and arresting efficiency for both flattening and flipping failure modes.</p></div>","PeriodicalId":49879,"journal":{"name":"Marine Structures","volume":"95 ","pages":"Article 103599"},"PeriodicalIF":3.9,"publicationDate":"2024-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139737935","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

Behaviour and confinement mechanism of circular concrete-filled aluminum alloy tubular stub columns under axial compression 轴向压缩下圆形混凝土填充铝合金管状短柱的行为和约束机制

IF 3.9 2区工程技术

Marine Structures Pub Date : 2024-02-14 DOI: 10.1016/j.marstruc.2024.103600

Xi-Feng Yan , Siqi Lin , Yan-Gang Zhao

{"title":"Behaviour and confinement mechanism of circular concrete-filled aluminum alloy tubular stub columns under axial compression","authors":"Xi-Feng Yan , Siqi Lin , Yan-Gang Zhao","doi":"10.1016/j.marstruc.2024.103600","DOIUrl":"https://doi.org/10.1016/j.marstruc.2024.103600","url":null,"abstract":"<div><p>Concrete-filled steel tubes are widely applied in offshore structures, which often being exposed to aggressive ocean climate. This has recently led to the introduction of concrete-filled aluminum alloy tubular (CFAT) columns, of which aluminum alloy tube is used as a superior anti-corrosion metal material. However, limited research has led to the design of CFAT columns not being included in the current design specifications, limiting their engineering applications. Accordingly, in this paper, an experimental program including 9 CFAT specimens was launched to further investigate the compressive behavior of CFAT short columns and to clarify the confinement mechanism in such columns. The test results indicate that the ultimate capacity of CFAT short columns is improved with the increase of concrete strength or the decrease of tube diameter-to-wall thickness ratio. Based on the experimental results, the finite element model (FEM) was established, and then used to clarify the confinement mechanism of CFAT columns and investigate the effects of the salient parameters on the behavior of such columns. By comparing with the existing experimental results, the accuracy of current strength calculation formulas for CFAT columns was assessed, and the conclusion indicates that there is an unexpected deviation in the prediction results. To this end, a simplified strength prediction formula for CFAT columns was proposed, which successfully introduced a novel confinement factor that well reflects the confinement effect of the concrete core. This confinement factor considers the effects of proof stress, concrete strength, and tube diameter-to-wall thickness ratio. Finally, compared with other formulas, the proposed formula has better performance in predicting results.</p></div>","PeriodicalId":49879,"journal":{"name":"Marine Structures","volume":"95 ","pages":"Article 103600"},"PeriodicalIF":3.9,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139733426","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

Simplified ultimate strength estimation method of rectangular plates under combined loads 矩形板在组合载荷作用下的简化极限强度估算方法

IF 3.9 2区工程技术

Marine Structures Pub Date : 2024-02-12 DOI: 10.1016/j.marstruc.2024.103592

Kinya Ishibashi , Daisuke Shiomitsu , Akira Tatsumi , Masahiko Fujikubo

{"title":"Simplified ultimate strength estimation method of rectangular plates under combined loads","authors":"Kinya Ishibashi , Daisuke Shiomitsu , Akira Tatsumi , Masahiko Fujikubo","doi":"10.1016/j.marstruc.2024.103592","DOIUrl":"https://doi.org/10.1016/j.marstruc.2024.103592","url":null,"abstract":"<div><p>A simple method for estimating the ultimate strength of rectangular plates under combined biaxial and shear loads is proposed. Although numerous studies have been conducted to predict the ultimate strength of plates, most conventional methods rely on empirical approaches that involve plastic correction of the elastic buckling strength or curve fitting through nonlinear finite element analysis (NLFEA) or experimental test results. For a more rational design of hull structures, it is important to develop an estimation method with a more theoretical basis corresponding to physical phenomena, such as post-buckling and yielding behavior, the effects of initial imperfections and material properties as well as the elastic buckling strength. Although some methods with the more theoretical basis were developed in previous studies, they often require numerical iterations such as the Newton-Raphson method to obtain load-deflection relationships. Our approach entails a thorough observation of the buckling and collapse behavior obtained from a series of NLFEA calculations, rather than merely investigating the magnitude of the ultimate strength derived from NLFEA. By applying the elastic-large deflection theory and considering the identified buckling modes, analytical solutions that describe the elastic post-buckling behaviors are derived. The ultimate strength is predicted by assessing the yield at pre-defined locations corresponding to the classified collapse modes. The proposed semi-analytical method eliminates the need for numerical iterative methods to obtain load-deflection relationships and provides a simple estimation of the ultimate strength. The accuracy of the proposed method is validated through a comparison with NLFEA results.</p></div>","PeriodicalId":49879,"journal":{"name":"Marine Structures","volume":"95 ","pages":"Article 103592"},"PeriodicalIF":3.9,"publicationDate":"2024-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0951833924000200/pdfft?md5=21a7ec3bc10d9677e5082fd1a9fef272&pid=1-s2.0-S0951833924000200-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139726527","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

VIV fatigue assessment by scaling of model test results 通过缩放模型试验结果进行 VIV 疲劳评估

IF 3.9 2区工程技术

Marine Structures Pub Date : 2024-02-08 DOI: 10.1016/j.marstruc.2023.103566

R. Peek , O. Sequeiros , J. Wu , M. Witz , D. Yin , H. Lie

{"title":"VIV fatigue assessment by scaling of model test results","authors":"R. Peek , O. Sequeiros , J. Wu , M. Witz , D. Yin , H. Lie","doi":"10.1016/j.marstruc.2023.103566","DOIUrl":"https://doi.org/10.1016/j.marstruc.2023.103566","url":null,"abstract":"<div><p>Bending strain data from 3 well-instrumented VIV model test programs on simply supported bare pipes under uniform flow are processed using rainflow counting to get fatigue damage rates directly. These are presented in terms a dimensionless fatigue-equivalent bending strain amplitude, ϵ<sub>e</sub>, which for the structurally undamped simply supported span under constant axial force <em>N</em> undergoing small rotations depends on 5 dimensionless parameters, and only weakly on the fatigue resistance curve used. Existing and new approximations are discussed as assessed whereby the number of dimensionless parameters that affect ϵ<sub>e</sub> may be reduced from 5 to 1. Thus a scaling approach is developed, whereby any VIV test can be scaled to represent any prototype at a current velocity determined by the scaling procedure. The procedure uses scaling only for the dynamic part of the response, and structural analysis for the static part. It works for single as well as multi-mode response. It is illustrated for a 150m-long prototype span subject to high currents. The test and/or scaling results are also compared to predictions by existing methods, including DNVGL-RP-F105 (“F105”) and Vivana. The example also illustrates how the proposed method can be used for partially strake-covered (“straked”) pipes, provided the strake coverage is similar for model and prototype. The scatter in the data gives an indication of the uncertainties involved in estimating VIV fatigue damage rates from limited experimental data where high-mode and multi-mode response is possible.</p></div>","PeriodicalId":49879,"journal":{"name":"Marine Structures","volume":"95 ","pages":"Article 103566"},"PeriodicalIF":3.9,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139709552","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

Optimal control of wave cycloidal rotors with passively morphing foils: An analytical and numerical study 带有被动变形箔片的摆线转子的优化控制：分析和数值研究

IF 3.9 2区工程技术

Marine Structures Pub Date : 2024-02-06 DOI: 10.1016/j.marstruc.2024.103597

Abel Arredondo-Galeana , Andrei Ermakov , Weichao Shi , John V. Ringwood , Feargal Brennan

{"title":"Optimal control of wave cycloidal rotors with passively morphing foils: An analytical and numerical study","authors":"Abel Arredondo-Galeana , Andrei Ermakov , Weichao Shi , John V. Ringwood , Feargal Brennan","doi":"10.1016/j.marstruc.2024.103597","DOIUrl":"https://doi.org/10.1016/j.marstruc.2024.103597","url":null,"abstract":"<div><p>In this paper we perform an analytical and numerical study of the performance of a wave cycloidal rotor in irregular waves, with passively morphing foils and variable rotational velocity control. The performance is measured in two ways: Mechanical power, and fatigue damage in a sample stress hot spot located at the fixed end of the hydrofoils. We consider different strategies seeking to both maximise power extraction and reduce fatigue damage. To maximise power, we consider both constant and variable rotational speed. To mitigate fatigue damage, we consider, for the first time, morphing foils in the context of a wave cycloidal rotor. By testing these control strategies in isolation and in combination, and with the aid of high performance computations, we find that variable rotational speed, in combination with morphing foils, offers the best compromise to enhance power production with a reduced structural penalty on the sample stress hot spot. Hence, in this work, we demonstrate that novel control strategies, such as those proposed in this work, can hold the key in reducing the levelised cost of energy and accelerate the commercialisation of the next generation of lift-based wave energy converters.</p></div>","PeriodicalId":49879,"journal":{"name":"Marine Structures","volume":"95 ","pages":"Article 103597"},"PeriodicalIF":3.9,"publicationDate":"2024-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S095183392400025X/pdfft?md5=1fbb08a55c3676746350fdae0677be4c&pid=1-s2.0-S095183392400025X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139694438","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

Experimental study on the mechanical properties and ultimate strength of accelerated corrosion on hull plates 船体板材加速腐蚀的力学性能和极限强度实验研究

IF 3.9 2区工程技术

Marine Structures Pub Date : 2024-01-31 DOI: 10.1016/j.marstruc.2024.103591

Liang Feng , Jiqian Zheng , Zhao Guo , Zhongyu Cui

{"title":"Experimental study on the mechanical properties and ultimate strength of accelerated corrosion on hull plates","authors":"Liang Feng , Jiqian Zheng , Zhao Guo , Zhongyu Cui","doi":"10.1016/j.marstruc.2024.103591","DOIUrl":"https://doi.org/10.1016/j.marstruc.2024.103591","url":null,"abstract":"<div><p><span>This study employed an accelerated corrosion method to investigate the impact of corrosion on the mechanical properties and ultimate strength of S420 steel hull plates. Initially, corrosion was accelerated using H</span><sub>2</sub>O<sub>2</sub><span> as a depolarizing agent, and corrosion parameters of the specimens were measured. Subsequently, ten tensile specimens<span> representing five different corrosion states of S420 steel were prepared to test the mechanical properties after corrosion. Simultaneously, 60 ship hull plate specimens, each measuring 146 mm in length, were prepared for ultimate strength experiments under four accelerated corrosion cycles and five slenderness conditions, resulting in a total of 20 operating conditions. The results revealed a linear decrease in various mechanical properties with increasing corrosion degradation. A bilinear stress-strain model considering the corrosion degradation was fitted. The ultimate strength of the hull plates linearly decreased with the increasing corrosion degradation, and the rate of decrease slowed with greater slenderness. Even at the same corrosion level, there was still a certain variability in ultimate strength, which gradually converged with increasing corrosion levels. A predictive formula for ultimate strength considering corrosion level, slenderness, and variability was fitted. The accuracy of the formula was verified through detailed error analysis, providing a practical reference for future structural design and corrosion management.</span></span></p></div>","PeriodicalId":49879,"journal":{"name":"Marine Structures","volume":"95 ","pages":"Article 103591"},"PeriodicalIF":3.9,"publicationDate":"2024-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139652616","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

Experimental investigation of two shared mooring configurations for a dual-spar floating offshore wind farm in irregular waves 不规则波浪中双杆浮式海上风电场两种共用系泊配置的实验研究

IF 3.9 2区工程技术

Marine Structures Pub Date : 2024-01-30 DOI: 10.1016/j.marstruc.2024.103579

Guodong Liang , Tomas Lopez-Olocco , Antonio Medina-Manuel , Leandro Antonio Saavedra-Ynocente , Antonio Souto-Iglesias , Zhiyu Jiang

{"title":"Experimental investigation of two shared mooring configurations for a dual-spar floating offshore wind farm in irregular waves","authors":"Guodong Liang , Tomas Lopez-Olocco , Antonio Medina-Manuel , Leandro Antonio Saavedra-Ynocente , Antonio Souto-Iglesias , Zhiyu Jiang","doi":"10.1016/j.marstruc.2024.103579","DOIUrl":"https://doi.org/10.1016/j.marstruc.2024.103579","url":null,"abstract":"<div><p>Shared mooring brings potential cost benefits to a floating wind farm. In such a wind farm, adjacent floaters are connected by shared lines and the total number of mooring lines is reduced. This paper presents an experimental study on a dual-spar floating offshore wind farm. In the first configuration, two spars are connected by a shared line. In the second configuration, a clump weight is added to the shared line. Irregular wave tests are performed for both configurations under operational and extreme wave conditions. The platform motions of one wind turbine and the mooring tension are measured during the tests. The influence of the added clump weight is found to be insignificant in the operational wave conditions. Under extreme waves, the added clump weight results in smaller platform motions in the wave direction and reduced tension oscillations in all mooring lines. With the additional clump weight, the extreme mooring tension in the shared line can decrease by 30% and fewer snap loading events occur, but the extreme tension in single lines can increase by 6%. This study contributes to an improved understanding of shared mooring systems and facilitates the development of model test methods for floating wind farms.</p></div>","PeriodicalId":49879,"journal":{"name":"Marine Structures","volume":"95 ","pages":"Article 103579"},"PeriodicalIF":3.9,"publicationDate":"2024-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0951833924000078/pdfft?md5=e22a182e60711d000e19529a48a682b8&pid=1-s2.0-S0951833924000078-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139652615","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

A simulation-based and data-augmented shear force inversion method for offshore platform connector 基于模拟和数据增强的海上平台连接器剪力反演方法

IF 3.9 2区工程技术

Marine Structures Pub Date : 2024-01-29 DOI: 10.1016/j.marstruc.2024.103577

Tao Zhang , Selda Oterkus , Erkan Oterkus , Xueliang Wang , Fang Wang , Song Shiqian

引用次数: 0

Frequency-domain hydroelastic stress analysis considering local bending effect based on a two-step procedure 基于两步程序的考虑局部弯曲效应的频域水弹性应力分析

IF 3.9 2区工程技术

Marine Structures Pub Date : 2024-01-29 DOI: 10.1016/j.marstruc.2024.103580

Shiyuan Zhang , Shixiao Fu , Shuai Li , Torgeir Moan , Yuwang Xu , Zhiyuan Pan

{"title":"Frequency-domain hydroelastic stress analysis considering local bending effect based on a two-step procedure","authors":"Shiyuan Zhang , Shixiao Fu , Shuai Li , Torgeir Moan , Yuwang Xu , Zhiyuan Pan","doi":"10.1016/j.marstruc.2024.103580","DOIUrl":"10.1016/j.marstruc.2024.103580","url":null,"abstract":"<div><p><span><span>In this study, a two-step stress analysis method to incorporate the global hydroelasticity<span> and local bending effect is developed in the frequency domain. In the first step, the continuous structure is discretized into several rigid modules connected by elastic beams to evaluate global hydroelastic responses, known as the beam-connected-discrete-modules (BCDM) hydroelasticity method. In the second step, the hydrodynamic and hydrostatic pressure as well as inertia forces in step one are mapped on an entire </span></span>finite element model to estimate the stresses by a quasi-static method. In this method, the boundary value problem solved in the generalized mode is replaced by multi-body hydrodynamics which has been extensively studied. The application of the proposed method is first verified against the results from modal-based method and published experimental data. Then, the effect of local bending and global flexible deformation on the stress is investigated through an intentionally flexible barge with an open-cross section. The results show that the local bending leads to an increase in the stress for some non-resonant frequencies. The global flexible </span>deformation mode contributes significantly to the stress when the resonance vibration is excited, which is caused by the associated inertia forces.</p></div>","PeriodicalId":49879,"journal":{"name":"Marine Structures","volume":"95 ","pages":"Article 103580"},"PeriodicalIF":3.9,"publicationDate":"2024-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139590504","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

Study on the bending behavior of reinforced thermoplastic pipes (RTPs): A theoretical continuum damage model and experimental tests 增强热塑性塑料管（RTP）弯曲行为研究：连续损伤理论模型和实验测试

IF 3.9 2区工程技术

Marine Structures Pub Date : 2024-01-27 DOI: 10.1016/j.marstruc.2024.103581

Xindong Ding , Shuqing Wang , Wencheng Liu , Svein Sævik , Lu Hai

{"title":"Study on the bending behavior of reinforced thermoplastic pipes (RTPs): A theoretical continuum damage model and experimental tests","authors":"Xindong Ding , Shuqing Wang , Wencheng Liu , Svein Sævik , Lu Hai","doi":"10.1016/j.marstruc.2024.103581","DOIUrl":"10.1016/j.marstruc.2024.103581","url":null,"abstract":"<div><p><span>A novel theoretical model is proposed to study the continuum damage mechanical (CDM) behavior of reinforced thermoplastic pipes (RTPs) under bending moments, in which stress analysis of composites, failure evaluation and stiffness degradation<span><span> are combined in loop calculation. Based on the existing homogenization assumption, the stress distribution of every ply could be calculated according to the </span>equilibrium equations<span> between the RTP and a hypothetical homogenous pipe. Once stresses of composite plies<span> satisfy Hashin-Yeh failure criterion, dominant failure modes are determined by filtering failure coefficients. Subsequently, the stiffness degradation model would be performed, in which a sine weight function is employed to consider the damage distribution along the hoop direction. Meanwhile, the von Mises criterion and Ramberg-Osgood curve are used to simulate the </span></span></span></span>material nonlinearity<span> of liner and coating. Four-point bending tests and numerical simulations were conducted to verify the proposed theoretical model. A user-defined VUMAT subroutine was employed to simulate the progressive failure of 3D composites. Compared with experimental tests and numerical simulations, the proposed model could give accurate predictions on the linear and nonlinear responses<span><span>, such as the bending stiffness, the stress field and the </span>damage propagation. Furthermore, different methods for the four-point bending test were also compared and good correlation found.</span></span></p></div>","PeriodicalId":49879,"journal":{"name":"Marine Structures","volume":"95 ","pages":"Article 103581"},"PeriodicalIF":3.9,"publicationDate":"2024-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139586016","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