Engineering Failure Analysis最新文献

Buckling and failure mechanisms of asymmetric composite sandwich panels subjected to shear loadings 非对称复合夹芯板在剪切荷载作用下的屈曲和破坏机理

IF 4.4 2区工程技术

Engineering Failure Analysis Pub Date : 2024-11-04 DOI: 10.1016/j.engfailanal.2024.109039

{"title":"Buckling and failure mechanisms of asymmetric composite sandwich panels subjected to shear loadings","authors":"","doi":"10.1016/j.engfailanal.2024.109039","DOIUrl":"10.1016/j.engfailanal.2024.109039","url":null,"abstract":"<div><div>Asymmetric sandwich technology serves as an effective option for introducing loads into sandwich structures in lieu of conventional inserts and joints in lightweight design of thin-walled aeronautical applications. In this study, buckling and failure behaviors are investigated on asymmetric sandwich panels with tapered regions subjected to shearing, where the panels are composed of CFRP laminates as skins and PMI foam as the core. Experimental data and observations are analyzed regarding critical loads, strain distributions, macro- and micro-scaled failure mechanisms. Detailed damage evolution is captured with the developed material and structural models. The influence of the core thickness on stability, load-bearing capacity and failure mechanisms is further investigated. Results show that the shear failure is mainly induced by buckling with an extensive matrix splitting fracture along the diagonal direction for sandwich panels with thin cores. Nonlinearity is observed in strain and deflection responses. Fiber pull-out is formed due to losing support of neighboring matrix. The fracture morphology of fiber breakage roughly appears oblique, indicating that the failure is mainly caused by the combination of tension and shearing. For sandwich panels with a thicker core, i.e. 10 mm and 12 mm, the failure mode switches to pure shear failure. Due to the intensification of tapered edges, local bugling occurs simultaneously with ultimate failure. The ultimate load presents a mounting-up and declining trend with the increase of core thickness, other than a monotonic trend. Conclusively, optimal design parameters exist, such as 10 mm core thickness in the studied case, regarding the load-bearing capacity.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593151","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

Research on TBM parameter optimization based on failure probability 基于失效概率的 TBM 参数优化研究

IF 4.4 2区工程技术

Engineering Failure Analysis Pub Date : 2024-11-02 DOI: 10.1016/j.engfailanal.2024.109036

{"title":"Research on TBM parameter optimization based on failure probability","authors":"","doi":"10.1016/j.engfailanal.2024.109036","DOIUrl":"10.1016/j.engfailanal.2024.109036","url":null,"abstract":"<div><div>This study addresses the over-reliance on operator experience in Tunnel Boring Machine (TBM) operations by proposing a failure probability-based decision-making method to enhance the scientific accuracy and reliability of construction decisions. In large deformation soft rock zones, TBMs are significantly affected by surrounding rock stress and deformation, which can lead to reduced tunneling speed or even shield jamming, severely impacting construction progress and safety. To reduce subjective biases in operator decision-making, this study combines the stress release coefficient with a failure probability model to establish a limit equilibrium equation. Using Monte Carlo simulations, failure probabilities under varying geological conditions are evaluated, and the optimal tunneling parameters are selected by analyzing the cumulative effect over time. Additionally, the study incorporates a Bayesian updating method, dynamically adjusting model parameters based on periodic monitoring data, further reducing uncertainty and improving the accuracy of the decision support system. The results show that while higher tunneling speeds increase the instantaneous failure probability, considering the cumulative effect over time, the overall failure index decreases with increased speed. Conversely, lower speeds result in a lower instantaneous failure probability but prolonged exposure to high-risk conditions increases the overall failure index. With this decision-making method, operators can quantitatively and in real-time adjust tunneling parameters under complex geological conditions, minimizing failure risks and improving construction efficiency.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593077","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

Corrosion fatigue analysis of suspenders on continuous suspension bridge under combined action of wind and traffic 风和交通联合作用下连续悬索桥吊索的腐蚀疲劳分析

IF 4.4 2区工程技术

Engineering Failure Analysis Pub Date : 2024-11-02 DOI: 10.1016/j.engfailanal.2024.109037

{"title":"Corrosion fatigue analysis of suspenders on continuous suspension bridge under combined action of wind and traffic","authors":"","doi":"10.1016/j.engfailanal.2024.109037","DOIUrl":"10.1016/j.engfailanal.2024.109037","url":null,"abstract":"<div><div>Suspenders and displacement-controlled device (DCD) are crucial force transmission components connecting the girder and the main cable in the continuous suspension bridge. These two structures will be subjected to environmental corrosion and fatigue loading simultaneously after the protection system fails. To investigate the safety of structure during the service, a comprehensive framework for corrosion fatigue analysis of continuous suspension bridge under the combined effects of wind and traffic flow was proposed. Taking a three-span continuous suspension bridge with DCD as engineering background, the wind-traffic combined load model was established and the fatigue life of the corroded suspenders was examined. Based on the Multilayer Perceptron algorithm, the impact of load form, environmental grade and DCD type on the corrosion fatigue performance of suspenders was analyzed. The results indicate that the fatigue life of suspender is significantly reduced due to uniform and pitting corrosion of the internal steel wires. The early failure mechanism of suspender is extremely sensitive to corrosion factors. Traffic load is the primary cause of fatigue damage to suspenders. Setting up DCD is beneficial for improving the corrosion fatigue life of the suspenders, and the selection of DCD type mainly depends on the topographical factors of the bridge site.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593149","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

The impact of water contamination on the performance failure of lithium grease 水污染对锂基润滑脂性能故障的影响

IF 4.4 2区工程技术

Engineering Failure Analysis Pub Date : 2024-11-02 DOI: 10.1016/j.engfailanal.2024.109035

{"title":"The impact of water contamination on the performance failure of lithium grease","authors":"","doi":"10.1016/j.engfailanal.2024.109035","DOIUrl":"10.1016/j.engfailanal.2024.109035","url":null,"abstract":"<div><div>The performance of grease is significantly influenced by water contamination in humid environments, such as those found in mines and offshore wind farms. In this study, the impact of water contamination on the physicochemical properties, rheological properties, film thickness and tribological properties of lithium greases was evaluated using a series of instruments and techniques, including rheometer, ball-on-disc contact test rig, UMT tribometer and others. Results show that the water content of 2% can enhance both the shear resistance and the extreme pressure capacity of lithium-based grease. The shear viscosity and the structural recoverability increase when water content is below 4%. However, when the water content reaches 8%, the equilibrium of the grease-water composite system is disrupted, resulting in the formation of soap fiber surface breakage notches and a notable reduction in shear viscosity. Furthermore, grease with a water content of 2% to 4% is capable of forming a thicker multi-phase mixed lubrication film, wherein soap fibers, base oil and water coexist. Conversely, the film thickness is observed to diminish rapidly when the water content reaches 6% to 10%. Moreover, the oil–water mixture exhibits inadequate lubricating oil film recovery ability in boundary lubrication. The coefficient of friction of water-contaminated grease increases significantly, reaching 2–3 times that of the initial fully lubricated state at a certain point with severe surface wear. These findings provide technical support for the utilization of lubricants in humid environments and highlight the potential impact of water contamination on lubricant performance.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593147","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 impact toughness and crack propagation behavior of Ti microalloyed weathering steel laser-MAG hybrid welded joints 钛微合金耐候钢激光-MAG 混合焊接接头的冲击韧性和裂纹扩展行为研究

IF 4.4 2区工程技术

Engineering Failure Analysis Pub Date : 2024-11-01 DOI: 10.1016/j.engfailanal.2024.109030

{"title":"Study on the impact toughness and crack propagation behavior of Ti microalloyed weathering steel laser-MAG hybrid welded joints","authors":"","doi":"10.1016/j.engfailanal.2024.109030","DOIUrl":"10.1016/j.engfailanal.2024.109030","url":null,"abstract":"<div><div>In this work, the effect of Ti microalloying on the impact toughness of weathering steel laser-MAG hybrid welded joints was investigated and the corresponding crack initiation and propagation mechanisms were revealed. The results show that the impact toughness of heat affect zone (HAZ) increased by 39.4% and weld metal (WM) by 70.9% compared to Ti-free weathering steel welded joints. The degree of improvement in impact toughness gradually increases with the direction from BM (base metal) to WM. In the WM, Ti element can refine the precipitations and reduce the shape and size of M−A constituents. Furthermore, the microstructure in the WM exhibits the obvious preferred orientations, i.e., the maximum IPF intensity value are concentrated around the [111] pole (the slip direction of BCC structure), which is more prone to slip under external forces. In the HAZ, the addition of Ti mainly plays a role in decreasing the size of precipitations, inducing AF precipitation and increasing the homogeneity of grain size. Therefore, the impact toughness of WM and HAZ for Ti microalloyed weathering steel welded joints is improved by hindering the crack propagation. In addition, in the WM, the main crack path is flatter and the number of secondary cracks is more than that in the HAZ, indicating that the impact toughness of WM is poorer.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142587436","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

The deteriorated tribological and noise performances of copper-based brake pads induced by the increased content of flake graphite 鳞片石墨含量增加导致铜基刹车片的摩擦学性能和噪音性能下降

IF 4.4 2区工程技术

Engineering Failure Analysis Pub Date : 2024-11-01 DOI: 10.1016/j.engfailanal.2024.109033

{"title":"The deteriorated tribological and noise performances of copper-based brake pads induced by the increased content of flake graphite","authors":"","doi":"10.1016/j.engfailanal.2024.109033","DOIUrl":"10.1016/j.engfailanal.2024.109033","url":null,"abstract":"<div><div>Enhancing the lubricity of copper-based brake pads has been viewed as a crucial strategy to boost braking performance. Flake graphite and the oxide film are two substances that are widely concerned with providing lubrication at the friction interface. However, the results from full-scale dynamometer in this work indicate that the increased content of flake graphite with stronger lubrication and iron particles that accelerate the generation of oxide film lead to a deterioration in tribological and noise performance. This is manifested by high sensitivity to clamping force, significant fading behavior, increased sound pressure level and high-frequency noise. The evidence from the worn surface suggests that flake graphite is susceptible to peeling off from the friction surface, thereby amplifying the instability of the friction surface. The unstable existence of both flake graphite and oxide film during emergency braking actually diminishes the lubrication of the friction interface, likely resulting in the degraded braking performance. The indication suggests that the development of high-performance copper-based brake pads should aim to achieve a harmonization of diverse properties, rather than emphasizing only specific aspects.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142579054","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

Solder joint lifetime model using AI framework operating on FEA data 使用基于有限元分析数据的人工智能框架建立焊点寿命模型

IF 4.4 2区工程技术

Engineering Failure Analysis Pub Date : 2024-11-01 DOI: 10.1016/j.engfailanal.2024.109032

{"title":"Solder joint lifetime model using AI framework operating on FEA data","authors":"","doi":"10.1016/j.engfailanal.2024.109032","DOIUrl":"10.1016/j.engfailanal.2024.109032","url":null,"abstract":"<div><div>The thermo-mechanical reliability of electronic systems is often limited by the crack growth within the solder joints. Addressing this issue requires careful consideration of the design of the package and solder pads. Finite Element Analysis (FEA) is widely used to predict crack growth and to model their lifetime. Traditionally, FEA post-processing methods rely on human expertise to select appropriate regions for evaluating plastic and creep strain at critical locations and correlating these values with experimental data using the Coffin-Manson equation, which predicts fatigue lifetime based on cyclic plastic strain. This study introduces a novel method for FEA post-processing of surface-mounted devices (SMD) on printed circuit boards (PCB) using artificial intelligence. The method transforms the FEA data into a 2D grid map of creep strain values and employs a Convolutional Neural Network (CNN) for automatic feature extraction. Afterwards, a fully connected layer correlates the extracted features with the experimental measured solder joint lifetime, effectively capturing nonlinear relationships.</div><div>The study focuses on the development of the concept of crack formation in the solder interconnects of ceramic based high-power LED packages used in the automotive industry for headlights. The validated FEA model is based on an extensive data set of 1800 LED packages including seven different ceramic-based LED packages and five different solders. The design of the ceramic LED package covers two-pad and three-pad footprint for soldering and thin film and thick film metallized ceramic carriers. Results show a strong agreement (R<sup>2</sup> Score is 99.867 %) between simulations and experimental data for ceramic LED packages. This automatic feature extraction from FEA data sets a new benchmark for improving solder reliability predictions, and it has proved to be better than established methods for lifetime prediction of solder joints.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142573109","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

Understanding surface morphology changes in stainless steel through stepwise cavitation erosion: A comprehensive study 通过逐步空化侵蚀了解不锈钢表面形貌的变化：综合研究

IF 4.4 2区工程技术

Engineering Failure Analysis Pub Date : 2024-11-01 DOI: 10.1016/j.engfailanal.2024.109017

{"title":"Understanding surface morphology changes in stainless steel through stepwise cavitation erosion: A comprehensive study","authors":"","doi":"10.1016/j.engfailanal.2024.109017","DOIUrl":"10.1016/j.engfailanal.2024.109017","url":null,"abstract":"<div><div>Cavitation damage, evolution, and features with time are serious problems confronting designers and users of high-speed hydraulic machines. The stepwise erosion technique clarifies the evolution of cavitation damage and its features over time. The technique involves exposing a test sample to repeated very low durations of erosion, followed by accurate relocation in the SEM. This allows fora detailed study of the actual wear processes within a material, providing a solid foundation for understanding material failure. The experiments were conducted using an ultrasonic vibratory horn functioning at 19.5 kHz frequency and 50 µm ± 0.2 um peak-to-peak amplitude. The tested material was cold-rolled austenitic stainless steel SUS 304 (18 Cr-8 Ni). The results show that the slip bands formed due to shock waves’ impact are the preferential sites for early material removals. Material removal starts gradually along the slip bands that form at the grain boundary and then progresses into the grain. The results also showed that the microjets formed pits that were a few micrometers in size and separated from one another. These pits have remained the same shape and size over time, confirming their limited role in the evolution of cavitation damage. The initiation and progression of inherent cracks resulting from plastic deformation, as well as the characteristics of dislodged particles, strongly support the conclusion that shockwave impacts cause fatigue failure as the mechanism of cavitation erosion.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142573110","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

Effects of irregular holes on load-bearing mechanism and capacity in prestressed concrete cylinder pipes 不规则孔洞对预应力混凝土圆筒管承重机理和承载能力的影响

IF 4.4 2区工程技术

Engineering Failure Analysis Pub Date : 2024-10-31 DOI: 10.1016/j.engfailanal.2024.109006

{"title":"Effects of irregular holes on load-bearing mechanism and capacity in prestressed concrete cylinder pipes","authors":"","doi":"10.1016/j.engfailanal.2024.109006","DOIUrl":"10.1016/j.engfailanal.2024.109006","url":null,"abstract":"<div><div>This study investigates the effects of irregular holes on the load-bearing mechanism and capacity of prestressed concrete cylinder pipes (PCCP). An internal pressure test was performed on a PCCP specimen containing multiple irregular holes, and a finite element numerical simulation was conducted to explore the impact of these holes. The results indicated that the presence of irregular holes caused significant anisotropic stress distribution, particularly at the inner wall of the concrete core, with stress concentrations around the holes. Cracks were initiated near the spigot end and propagated axially as the internal pressure increased. The load-bearing process of the PCCP evolved in three stages: (1) the prestressed wires bore the majority of the load, (2) the concrete began sustaining a portion of the load as it experienced tensile stress, and (3) the concrete underwent plastic damage, transferring the load to the steel cylinder and prestressed wires. The internal pressure of PCCP model with multiple irregular holes associated with the serviceability limit-states was 0.23 MPa, representing only 26.4 % of the intact model, which was 0.87 MPa. However, the difference in ultimate load-bearing capacity between the two models was minimal. These findings underscore the necessity of timely repairs to prevent the worsening of erosion in PCCPs with irregular holes.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593150","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

Role of residual stress in the failure of the bend of superheater Cr-Mo steel tube working in high-temperature conditions 残余应力在高温条件下工作的过热器铬钼钢管弯曲失效中的作用

IF 4.4 2区工程技术

Engineering Failure Analysis Pub Date : 2024-10-29 DOI: 10.1016/j.engfailanal.2024.109018

{"title":"Role of residual stress in the failure of the bend of superheater Cr-Mo steel tube working in high-temperature conditions","authors":"","doi":"10.1016/j.engfailanal.2024.109018","DOIUrl":"10.1016/j.engfailanal.2024.109018","url":null,"abstract":"<div><div>This study deals with the material analysis of a Cr-Mo steel superheater at the bending point. The crack occurred on the inside of the bend after 4,300 h of boiler operation, which resulted in a leak of the working medium and a forced device shutdown. The planned service life of the superheater tubes was 34,000 h. The operating parameters of the boiler were as follows: steam output pressure 3.2–3.6 MPa, steam output temperature 440–450 °C. Cracks were found on the lateral surfaces of the bends of the superheater lower tubes. Visual, microscopic, and EDS SEM analyses were performed to determine the cause of the damage. Microscopic analysis showed that crack initiation occurred near the maximum bend on the inner surface of the tubes, where the present pits acted as stress concentrators. EDS SEM confirmed that the predominant iron content in the corrosion layer was related to the formation of tubercles above the corrosion pits, which participated in the corrosion-mechanical nature of the failure. The calculated residual stress values were significant and concentrated in both the intrados and extrados bending regions of the tube. Finite element model (FEM) was used to locate the post-bending stress distribution of the tube and confirmed that a combination of post-bending residual stresses, steam pressure and temperature, and steel tube pitting caused cracks to form and propagate. The distribution of local mechanical stresses through a cross-section of the wall thickness of the superheated tube was experimentally carried out using an electron backscattered diffraction (EBSD) analysis. Theobtained results were correlated with the Mises residual stress.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593148","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