Applied Mechanics Reviews最新文献_第2页

Analytical and Numerical Investigation of Fatigue Life in Rectangular Plates with Opposite Semicircular Edge Single Notches 具有相对半圆边单缺口矩形板疲劳寿命的分析与数值研究

1区工程技术

Applied Mechanics Reviews Pub Date : 2023-08-31 DOI: 10.3390/applmech4030049

Kristaq Hazizi, Mohammad Ghaleeh, Shafqat Rasool

引用次数: 0

Analysis of Acid Diffusion Effects on Physical Properties of Polymer Composites: A Combined Study of Mechanical and Electrical Characterization 酸扩散对聚合物复合材料物理性能的影响分析:力学和电学表征的结合研究

IF 14.3 1区工程技术

Applied Mechanics Reviews Pub Date : 2023-08-31 DOI: 10.3390/applmech4030050

S. Tamayo-Vegas, K. Lafdi, M. Tarfaoui, K. Lafdi, Mohamed Daly

{"title":"Analysis of Acid Diffusion Effects on Physical Properties of Polymer Composites: A Combined Study of Mechanical and Electrical Characterization","authors":"S. Tamayo-Vegas, K. Lafdi, M. Tarfaoui, K. Lafdi, Mohamed Daly","doi":"10.3390/applmech4030050","DOIUrl":"https://doi.org/10.3390/applmech4030050","url":null,"abstract":"In this study, we examined the impact of carbon nanotube (CNT) concentration on the mechanical properties of epoxy/CNT composites under acid exposure. Samples with varying CNT concentrations (0% to 5%) were fabricated and characterized using dynamic mechanical analysis (DMA) and nanoindentation. Beyond the percolation threshold, the composites experienced decreased bulk mechanical properties due to CNT agglomeration. Acid exposure for one week and one month revealed a gradient of properties from the sample’s skin to its core. Overall, the composites exhibited modified physical properties, with degradation influenced by the CNT concentration. Higher concentrations acted as barriers but also created pathways for acid diffusion through pores surrounding CNT agglomerates. The agreement between nanoindentation and vector network analyzer (VNA) measurements further supported our findings. This convergence of mechanical and electromagnetic characterization techniques holds promise for wireless structural health monitoring (SHM) applications. Our study enhances the understanding of epoxy/CNT composites for SHM applications. The relationship between CNT concentration, acid exposure, and mechanical properties guides material selection and the development of real-time damage-detection techniques. Integrating multiple measurement techniques, as demonstrated by the agreement between nanoindentation and VNA data, provides a comprehensive understanding of structural behavior, improving SHM practices.","PeriodicalId":8048,"journal":{"name":"Applied Mechanics Reviews","volume":"73 1","pages":""},"PeriodicalIF":14.3,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89190018","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

Study of a Square Single-Phase Natural Circulation Loop Using the Lattice Boltzmann Method 格子玻尔兹曼法研究方形单相自然循环回路

IF 14.3 1区工程技术

Applied Mechanics Reviews Pub Date : 2023-08-28 DOI: 10.3390/applmech4030048

J. Bocanegra, A. Marchitto, M. Misale

{"title":"Study of a Square Single-Phase Natural Circulation Loop Using the Lattice Boltzmann Method","authors":"J. Bocanegra, A. Marchitto, M. Misale","doi":"10.3390/applmech4030048","DOIUrl":"https://doi.org/10.3390/applmech4030048","url":null,"abstract":"Natural circulation loops are thermohydraulic circuits used to transport heat from a source to a sink in the absence of a pump, using the forces induced by the thermal expansion of a working fluid to circulate it. Natural circulation loops have a wide range of engineering applications such as in nuclear power plants, solar systems, and geothermic and electronic cooling. The Lattice Boltzmann Method was applied to the simulation of this thermohydraulic system. This numerical method has several interesting features for engineering applications, such as parallelization capabilities or direct temporal convergence. A 2D model of a single-phase natural circulation mini-loop with a small inner diameter was implemented and tested under different operation conditions following a double distribution function approach (coupling a lattice for the fluid and a secondary lattice for the thermal field). An analytical relationship between the Reynolds number and the modified Grashof number was used to validate the numerical model. Two regimes were found for the circulation, a laminar regime for low Reynolds numbers and a non-laminar regime characterized by a traveling vortex near the heater and cooler’s walls. Both regimes did not present flux inversion and are considered stable. The recirculation of the fluid can explain some of the heat transfer characteristics in each regime. Changing the Prandtl number to a higher value affects the transient response, increasing the temperature and velocity oscillations before reaching the steady state.","PeriodicalId":8048,"journal":{"name":"Applied Mechanics Reviews","volume":"62 1","pages":""},"PeriodicalIF":14.3,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89204371","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: 2

Inelastic Behavior of Steel and Composite Frame Structure Subjected to Earthquake Loading 钢和组合框架结构在地震荷载作用下的非弹性性能

IF 14.3 1区工程技术

Applied Mechanics Reviews Pub Date : 2023-08-16 DOI: 10.3390/applmech4030047

Param D. Gajbhiye, Nuha S. Mashaan, V. Bhaiya, R. Wankhade, S. Vishnu

{"title":"Inelastic Behavior of Steel and Composite Frame Structure Subjected to Earthquake Loading","authors":"Param D. Gajbhiye, Nuha S. Mashaan, V. Bhaiya, R. Wankhade, S. Vishnu","doi":"10.3390/applmech4030047","DOIUrl":"https://doi.org/10.3390/applmech4030047","url":null,"abstract":"Steel construction is used more often these days as an alternative to the R.C.C. when lightweight, high-strength, large-span structures with a faster erection are required. Extensive studies have been conducted by researchers to study the seismic performance of reinforced concrete and steel structures, both in terms of elastic and inelastic behavior. Composite construction is also a recent advancement in the building industry with similar advantages. However, no emphasis has been given to the comparison between the inelastic behavior of steel and composite structures when subjected to lateral loads. This study compares the inelastic behavior of steel and a composite frame designed to have the same plastic moment capacity for structural members. The responses, such as the formation of hinges, story drifts, story displacements, lateral stiffness, ductility, maximum strength, energy dissipated, joint accelerations, and performance points, are compared with the aid of the building analysis and design software ETABS-18. For this, response spectrum analysis, pushover analysis, and nonlinear direct integration time history analysis have been performed on both frames. For design and analysis, international codes, such as IS 800-2007, IS 875 (Part I, II, IV), IS 1893-2002, AISC 360 (16 and 10), and FEMA 440, have been used. Part of this study also aims at comparing the response of these frames when subjected to near-field and far-field earthquakes. It can be concluded from the results that the post-yield performance of the composite frame is superior to that of the steel frame when seismically excited.","PeriodicalId":8048,"journal":{"name":"Applied Mechanics Reviews","volume":"47 1","pages":""},"PeriodicalIF":14.3,"publicationDate":"2023-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81829795","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

The Compressive Strength and Microstructure of Alkali-Activated Mortars Utilizing By-Product-Based Binary-Blended Precursors 副产物二元混合前驱体碱活化砂浆的抗压强度和微观结构

IF 14.3 1区工程技术

Applied Mechanics Reviews Pub Date : 2023-08-11 DOI: 10.3390/applmech4030046

O. Elbasir, M. Johari, Z. Ahmad, Nuha S. Mashaan, A. Milad

{"title":"The Compressive Strength and Microstructure of Alkali-Activated Mortars Utilizing By-Product-Based Binary-Blended Precursors","authors":"O. Elbasir, M. Johari, Z. Ahmad, Nuha S. Mashaan, A. Milad","doi":"10.3390/applmech4030046","DOIUrl":"https://doi.org/10.3390/applmech4030046","url":null,"abstract":"Researchers have investigated the feasibility of using ultrafine palm oil fuel ash (u-POFA) as a cement replacement material because of its potential to reduce the environmental impact of concrete production. u-POFA, a by-product of palm oil fuel combustion, is a suitable replacement for Portland cement in concrete mixes because of its sustainability and cost-effectiveness. This study investigated the microstructural and compressive strengths of alkali-activated mortars (AAMs) based on fly ash (FA) and granulated blast-furnace slag (GBFS) being added with varying percentages of u-POFA. The mixture samples were prepared in eighteen mortars using sodium metasilicate (Na2SiO3) as the source material and sodium hydroxide (NaOH) as the alkaline activator. This study used field-emission scanning electron microscopy coupled with energy-dispersive X-ray spectrometry, X-ray diffraction, X-ray fluorescence, and Fourier-transform infrared spectroscopy to characterize the binary-blended mortars after 28 days of curing and determined the strength of the FA+GBFS (87.80 MPa), u-POFA+GBFS (88.87 MPa), and u-POFA+FA mortars (54.82 MPa). The mortars’ compressive strength was influenced by the CaO/SiO2 and SiO2/Al2O3 ratios in the mixture, which was directly due to the formation rate of geopolymer products of the calcium–alumina–silicate–hydrate (C–(A)–S–H), aluminosilicate (N–A–S–H), and calcium–silicate–hydrate (C–S–H) phases. Based on the contents of FA and GBFS, u-POFA significantly enhanced concrete strength; therefore, u-POFA used in a suitable proportion could enhance binary-blended AAMs’ microstructure.","PeriodicalId":8048,"journal":{"name":"Applied Mechanics Reviews","volume":"33 1","pages":""},"PeriodicalIF":14.3,"publicationDate":"2023-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80101691","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

A Comprehensive Review on the Novel Principles, Development and Applications of Triboelectric Nanogenerators 纳米摩擦发电机的新原理、发展及应用综述

1区工程技术

Applied Mechanics Reviews Pub Date : 2023-07-28 DOI: 10.1115/1.4056391

Dogus Hurdoganoglu, Babak Safaei, Jia Cheng, Zhaoye Qin, Saeid Sahmani

{"title":"A Comprehensive Review on the Novel Principles, Development and Applications of Triboelectric Nanogenerators","authors":"Dogus Hurdoganoglu, Babak Safaei, Jia Cheng, Zhaoye Qin, Saeid Sahmani","doi":"10.1115/1.4056391","DOIUrl":"https://doi.org/10.1115/1.4056391","url":null,"abstract":"Abstract The major aim of this study is to provide a broad review of the fundamental ideas, progress, and utilization of triboelectric nanogenerators (TENGs). The modes and operations of numerous triboelectric nanogenerator configurations along with applications and materials are also discussed. Triboelectric nanogenerators, a ground-breaking power production technology, were unveiled in 2012 and classified as one of the most effective generators to convert unused mechanical energy into electrical energy to run a wide range of devices. Triboelectric nanogenerators have made significant progress since the creation of this novel power-generation technology. The operating principles of various modes, such as freestanding triboelectric-layer, single-electrode, lateral sliding, and vertical contact-separation have also been carefully investigated in order to give readers a deeper understanding of the technology. The key applications of TENGs, such as high voltage power supply, blue energy, self-power sensors, and micro/nano-energy, are also described in this work along with concepts for further research. As a result, triboelectric nanogenerators are very important and attractive technology with advantages of low cost, straightforward construction, simple fabrication, high efficiency, and relatively high output performance. Wide range of material choice allows researchers to use the technology in many configurations with multiple applications. Numerous scientific modeling and analysis are also reviewed for a more solid understanding of this revolutionary and unique technology.","PeriodicalId":8048,"journal":{"name":"Applied Mechanics Reviews","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134919892","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: 6

Nanoparticle Size and Heat Pipe Angle Impact on the Thermal Effectiveness of a Cylindrical Screen Mesh Heat Pipe 纳米颗粒尺寸和热管角度对圆柱筛网热管热效率的影响

IF 14.3 1区工程技术

Applied Mechanics Reviews Pub Date : 2023-07-27 DOI: 10.3390/applmech4030045

Prabhu Alphonse, Karthikeyan Muthukumarasamy, Ratchagaraja Dhairiyasamy

{"title":"Nanoparticle Size and Heat Pipe Angle Impact on the Thermal Effectiveness of a Cylindrical Screen Mesh Heat Pipe","authors":"Prabhu Alphonse, Karthikeyan Muthukumarasamy, Ratchagaraja Dhairiyasamy","doi":"10.3390/applmech4030045","DOIUrl":"https://doi.org/10.3390/applmech4030045","url":null,"abstract":"This study examines the effects of particle size and heat pipe angle on the thermal effectiveness of a cylindrical screen mesh heat pipe using silver nanoparticles (Ag) as the test substance. The experiment investigates three different particle sizes (30 nm, 50 nm, and 80 nm) and four different heat pipe angles (0°, 45°, 60°, and 90°) on the heat transmission characteristics of the heat pipe. The results show that the thermal conductivity of the heat pipe increased with an increase in heat pipe angle for all particle sizes, with the highest thermal conductivity attained at a 90° heat pipe angle. Furthermore, the thermal resistance of the heat pipe decreased as the particle size decreased for all heat pipe angles. The thermal conductivity measurements of the particle sizes—30, 50, and 80 nm—were 250 W/mK, 200 W/mK, and 150 W/mK, respectively. The heat transfer coefficient values for particle sizes 30 nm, 50 nm, and 80 nm were 5500 W/m2K, 4500 W/m2K, and 3500 W/m2K, respectively. The heat transfer coefficient increased with increased heat pipe angle for all particle sizes, with the highest heat transfer coefficient obtained at a 90° heat pipe angle. The addition of Ag nanoparticles at a volume concentration of 1% reduced the thermal resistance of the heat pipe, resulting in improved heat transfer performance. At a heat load of 150 W, the thermal resistance decreased from 0.016 °C/W without nanoparticles to 0.012 °C/W with 30 nm nanoparticles, 0.013 °C/W with 50 nm nanoparticles, and 0.014 °C/W with 80 nm nanoparticles. This study also found that the heat transfer coefficient increased with increased heat pipe angle for all particle sizes, with the highest heat transfer coefficient obtained at a 90° heat pipe angle.","PeriodicalId":8048,"journal":{"name":"Applied Mechanics Reviews","volume":"62 1","pages":""},"PeriodicalIF":14.3,"publicationDate":"2023-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85667928","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: 1

Smart Structures Innovations Using Robust Control Methods 采用鲁棒控制方法的智能结构创新

IF 14.3 1区工程技术

Applied Mechanics Reviews Pub Date : 2023-07-19 DOI: 10.3390/applmech4030044

Amalia Moutsopoulou, G. Stavroulakis, M. Petousis, N. Vidakis, A. Pouliezos

{"title":"Smart Structures Innovations Using Robust Control Methods","authors":"Amalia Moutsopoulou, G. Stavroulakis, M. Petousis, N. Vidakis, A. Pouliezos","doi":"10.3390/applmech4030044","DOIUrl":"https://doi.org/10.3390/applmech4030044","url":null,"abstract":"This study’s goal is to utilize robust control theory to effectively mitigate structural oscillations in smart structures. While modeling the structures, two-dimensional finite elements are used to account for system uncertainty. Advanced control methods are used to completely reduce vibration. Complete vibration suppression is achieved using advanced control techniques. In comparison to traditional control approaches, Hinfinity techniques offer the benefit of being easily adaptable to issues with multivariate systems. It is challenging to simultaneously optimize robust performance and robust stabilization. One technique that approaches the goal of achieving robust performance in mitigating structural oscillations in smart structures is H-infinity control. H-infinity control empowers control designers by enabling them to utilize traditional loop-shaping techniques on the multi-variable frequency response. This approach enhances the robustness of the control system, allowing it to better handle uncertainties and disturbances while achieving desired performance objectives. By leveraging H-infinity control, control designers can effectively shape the system’s frequency response to enhance stability, tracking performance, disturbance rejection, and overall robustness.","PeriodicalId":8048,"journal":{"name":"Applied Mechanics Reviews","volume":"46 1","pages":""},"PeriodicalIF":14.3,"publicationDate":"2023-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76626165","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: 3

Dynamic Response Analysis of Wind Turbine Structure to Turbulent Wind Load: Comparative Assessment in Time and Frequency Domains 风力发电机结构对湍流风荷载的动力响应分析:时域和频域的比较评估

IF 14.3 1区工程技术

Applied Mechanics Reviews Pub Date : 2023-07-17 DOI: 10.3390/applmech4030043

Hailay Kiros Kelele, M. Kahsay, T. Nielsen

{"title":"Dynamic Response Analysis of Wind Turbine Structure to Turbulent Wind Load: Comparative Assessment in Time and Frequency Domains","authors":"Hailay Kiros Kelele, M. Kahsay, T. Nielsen","doi":"10.3390/applmech4030043","DOIUrl":"https://doi.org/10.3390/applmech4030043","url":null,"abstract":"This study investigates wind turbine structural dynamics using stochastic analysis and computational methods in both the time and frequency domains. Simulations and experiments are utilized to evaluate the dynamic response of a wind turbine structure to turbulent wind loads, with the aim of validating the results based on real wind farm conditions. Two approaches are employed to analyze the dynamic responses: the frequency domain modal analysis approach, which incorporates von Kármán spectra to represent the turbulent wind loads, and the time domain Monte Carlo simulation and Newmark methods, which generate wind loads and determine dynamic responses, respectively. The results indicate that, for a larger number of samples, both methods consistently yield simulated turbulent wind loads, dynamic responses and peak frequencies. These findings are further validated through experimental data. However, when dealing with a smaller number of samples, the time domain analysis produces distorted results, necessitating a larger number of samples to achieve accurate findings, while the frequency domain method maintains accuracy. Therefore, the accurate analysis of wind turbine structural dynamics can be achieved using simulations in both the time and frequency domains, considering the importance of the number of samples when choosing between time domain and frequency domain analyses. Taking these considerations into account allows for a more comprehensive and robust analysis, ultimately leading to more effective outcomes.","PeriodicalId":8048,"journal":{"name":"Applied Mechanics Reviews","volume":"113 1","pages":""},"PeriodicalIF":14.3,"publicationDate":"2023-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80600390","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

Passive-Tuned Mass Dampers for the Pointing Accuracy Mitigation of VLBI Earth-Based Antennae Subject to Aerodynamic Gust 气动阵风作用下VLBI地基天线指向精度降低的被动调谐质量阻尼器

IF 14.3 1区工程技术

Applied Mechanics Reviews Pub Date : 2023-07-13 DOI: 10.3390/applmech4030042

Victor E. L. Gasparetto, Jackson Reid, M. ElSayed

{"title":"Passive-Tuned Mass Dampers for the Pointing Accuracy Mitigation of VLBI Earth-Based Antennae Subject to Aerodynamic Gust","authors":"Victor E. L. Gasparetto, Jackson Reid, M. ElSayed","doi":"10.3390/applmech4030042","DOIUrl":"https://doi.org/10.3390/applmech4030042","url":null,"abstract":"This paper proposes an optimization procedure to achieve the best configuration of multiple degrees of freedom Tuned Mass Dampers (TMDs) to mitigate the pointing error of Very-Long-Baseline Interferometry (VLBI) Earth-based radio antennae operating under aerodynamic gust conditions. In order to determine the optimum sets of TMDs, a Multi-Objective design optimization employing a genetic algorithm is implemented. A case study is presented where fourteen operational scenarios of wind gust are considered, employing two models of atmospheric disturbances, namely the Power Spectral Density (PSD) function with a statistical profile presented by the Davenport Spectrum (DS) and a Tuned Discrete Gust (TDG) modeled as a one-minus cosine signal. It is found that the optimal configurations of TMDs are capable of reducing the pointing error of the antenna by an average of 66% and 50% for the PSD and TDG gust excitation scenarios, respectively, with a mass inclusion of 1% of the total mass of the antenna structure. The optimal TMD parameters determined herein can be utilized for design and field implementation in antenna systems, such that their structural efficiency can be enhanced for radio astronomy applications.","PeriodicalId":8048,"journal":{"name":"Applied Mechanics Reviews","volume":"5 1","pages":""},"PeriodicalIF":14.3,"publicationDate":"2023-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75751479","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