Ultrasonics最新文献

{"title":"A method of enhanced shear wave elastography based on Chirp coded excitation","authors":"Jingwen Ding ,&nbsp;Yiheng Li ,&nbsp;Yang Jiao ,&nbsp;Ninghao Wang ,&nbsp;Yaoyao Cui","doi":"10.1016/j.ultras.2025.107569","DOIUrl":"10.1016/j.ultras.2025.107569","url":null,"abstract":"<div><div>Shear Wave Elastography (SWE) is an imaging technique that detects shear waves generated by tissue excited by Acoustic Radiation Force (ARF), and characterizes the mechanical properties of soft tissue by analyzing the propagation velocity of shear wave. ARF induces a change in energy density through the nonlinear propagation of ultrasound waves, which drives the tissue to generate shear waves. However, the amplitude of shear waves generated by ARF is weak, and the shear waves are strongly attenuated in vivo. Furthermore, the shear waves are usually drowned out by noise at deep locations, which presents a challenge in the detection of shear waves and low signal-to-noise ratios. In this paper, we investigate the feasibility of applying the Chirp coded signal for shear wave excitation (Chirp-SWE) in ARF-based shear wave elastography. The use of Chirp coded excitation of push waveforms was employed to enhance the action of ARF, thereby effectively exciting shear waves. Comparative experiments were carried out with conventional sine long pulses (SWE) and the Barker coded signal (Barker-SWE). The analysis of theoretical and simulation results revealed that Chirp-SWE could increase the excitation energy by approximately 10% compared to conventional SWE and Barker-SWE. The results of the elastic phantom experiments demonstrated that the average peak axial particle velocity obtained by Chirp-SWE was approximately 30%–50% higher, which facilitated the formation of a more stable shear wave. Additionally, it exhibited a higher signal-to-noise ratio during elasticity measurements. The in vitro liver experiments further validated the feasibility of implementing Chirp-SWE in tissues. The results demonstrated the feasibility and advantages of Chirp coded excitation of push waveforms in improving shear wave elastography results. It is expected that this will enhance the accuracy and robustness of soft tissue elastography.</div></div>","PeriodicalId":23522,"journal":{"name":"Ultrasonics","volume":"149 ","pages":"Article 107569"},"PeriodicalIF":3.8,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143012610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sensitivity of Lamb waves in viscoelastic polymer plates to surface contamination","authors":"Jakub Spytek ,&nbsp;Daniel A. Kiefer ,&nbsp;Ros Kiri Ing ,&nbsp;Claire Prada ,&nbsp;Jérôme Grando ,&nbsp;Julien de Rosny","doi":"10.1016/j.ultras.2025.107571","DOIUrl":"10.1016/j.ultras.2025.107571","url":null,"abstract":"<div><div>Detecting surface contamination on thin thermoformed polymer plates is a critical issue for various industrial applications. Lamb waves offer a promising solution, though their effectiveness is challenged by the strong attenuation and anisotropy of the polymer plates. This issue is addressed in the context of a calcium carbonate (CaCO<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>) layer deposited on a polypropylene (PP) plate. First, the viscoelastic properties of the PP material are determined using a genetic algorithm inversion of data measured with a scanning laser vibrometer. Second, using a bi-layer plate model, the elastic properties and thickness of the CaCO<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> layer are estimated. Based on the model, the sensitivity analysis is performed, demonstrating considerable effectiveness of the A1 Lamb mode in detecting thin layers of CaCO<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> compared to Lamb modes A0 and S0. Finally, a direct application of this work is illustrated through in-situ monitoring of CaCO<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> contaminants using a straightforward inter-transducer measurement.</div></div>","PeriodicalId":23522,"journal":{"name":"Ultrasonics","volume":"149 ","pages":"Article 107571"},"PeriodicalIF":3.8,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143012620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ultrasonic characterization of 3D-printed polymer objects","authors":"Timoteo F. de Oliveira ,&nbsp;André C.M. Cavalheiro ,&nbsp;F. Buiochi ,&nbsp;Marcos S.G. Tsuzuki ,&nbsp;José P. Leão-Neto ,&nbsp;Giclênio C. Silva ,&nbsp;Glauber T. Silva ,&nbsp;J. Henrique Lopes","doi":"10.1016/j.ultras.2025.107572","DOIUrl":"10.1016/j.ultras.2025.107572","url":null,"abstract":"<div><div>3D printing technology, also known as Additive Manufacturing (AM), has revolutionized object prototyping, offering a simple, cost-effective, and efficient approach to creating structures with diverse spatial features. However, the mechanical properties of 3D-printed structures are highly dependent on the material type and manufacturing technique employed. In this study, ultrasonic testing methods were used to comprehensively characterize standard samples produced using two popular printing techniques: material extrusion and vat photopolymerization. The investigation focuses on seven commonly used 3D printing polymer materials, namely nylon, PET-G, flexible polymer, polycarbonate, acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), and photopolymer resin. Through ultrasonic testing, the mechanical parameters of objects made of different polymer materials were found. Some of these parameters are Young’s modulus, shear modulus, acoustic impedance, and absorption. A comparative analysis of these parameters in different objects provides insights about their respective performance and behavior. This information may be useful to enhance the design and performance of ultrasonic lenses and lab-on-a-chip devices. Findings indicate that the vat photopolymerization printing process yields high-quality samples that exhibit minimal deviations in thickness, diameter, and surface parallelism. Moreover, microscopic analysis of the vat photopolymerization samples revealed low levels of porosity, which suggests that the material can be considered homogeneous. In contrast, the material extrusion samples showed significant porosity in the form of gaps between the deposited filaments, which had a direct impact on their mechanical and acoustic properties.</div></div>","PeriodicalId":23522,"journal":{"name":"Ultrasonics","volume":"149 ","pages":"Article 107572"},"PeriodicalIF":3.8,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143012629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Monitoring defects in plates using topological acoustic sensing and sideband peak counting","authors":"I-Ting Ho ,&nbsp;Krishna Muralidharan ,&nbsp;Keith Runge ,&nbsp;Araceli Hernandez Granados ,&nbsp;Tribikram Kundu ,&nbsp;Pierre A. Deymier","doi":"10.1016/j.ultras.2025.107568","DOIUrl":"10.1016/j.ultras.2025.107568","url":null,"abstract":"<div><div>We demonstrate an integrated non-destructive inspection methodology that employs the nonlinear ultrasonics-based sideband peak counting (SPC) technique in conjunction with topological acoustics (TA) sensing to comprehensively characterize the acoustic response of steel plates that contain differing levels of damage. By combining the SPC technique and TA, increased sensitivity to defect/damage detection as well as the ability to spatially resolve the presence of defects was successfully established. Towards this end, using a Rockwell hardness indenter, steel plates were subject to one, three and five centrally located indentations respectively. The acoustic response of the plate as a function of number of indentations was examined at a frequency range between 50 kHz and 800 kHz, from which the change in a global geometric phase was evaluated. Here, geometric phase is a measure of the topological acoustic field response to the spatial locations of the indentations within the steel plates. The global geometric phase unambiguously showed an increase with increasing number of indentations. In addition, spatial variations in a ‘local’ geometric phase as well as spatial variations in the SPC-index (SPC-I) were also determined. Spatial variations in both the local geometric phase as well as the SPC-I were particularly significant across the indentations for frequencies below 300 kHz, and by combining the respective spatial variations in the SPC-I and geometric phase, the locations of the indentations were accurately identified. The developed SPC-TA nondestructive method represents a promising technique for detecting and evaluating defects in structural materials.</div></div>","PeriodicalId":23522,"journal":{"name":"Ultrasonics","volume":"149 ","pages":"Article 107568"},"PeriodicalIF":3.8,"publicationDate":"2025-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143012614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimation of the phase velocity dispersion curves for viscoelastic materials using Point Limited Shear Wave Elastography","authors":"Wiktor Jachym ,&nbsp;Matthew W. Urban ,&nbsp;Piotr Kijanka","doi":"10.1016/j.ultras.2025.107566","DOIUrl":"10.1016/j.ultras.2025.107566","url":null,"abstract":"<div><div>Ultrasound shear wave elastography (SWE) is widely used in clinical applications for non-invasive measurements of soft tissue viscoelasticity. The study of tissue viscoelasticity often involves the analysis of shear wave phase velocity dispersion curves, which show how the phase velocity varies with frequency or wavelength.</div><div>In this study, we propose an alternative method to the two-dimensional Fourier transform (2D-FT) and Phase Gradient (PG) methods for shear wave phase velocity estimation. We introduce a new method called Point Limited Shear Wave Elastography (PL-SWE), which aims to reconstruct phase velocity dispersion curves using a minimal number of measurement points in the spatial domain (as few as two signals can be utilized). We investigated how the positioning of the first signal and the distance between selected signals affect the shear wave velocity dispersion estimation in PL-SWE. The effectiveness of this novel approach was evaluated through the analysis of analytical phantom data in viscoelastic media, along with experimental data from custom-made tissue-mimicking elastic and viscoelastic phantoms, and <em>in vivo</em> renal transplant data.</div><div>A comparative analysis with the 2D-FT technique revealed that PL-SWE provided phase velocity dispersion curve estimates with root mean squared percentage error (RMSPE) values of less than 1.61% for analytical phantom data, 1.58% for elastic phantoms, 4.29% for viscoelastic phantoms and 7.68% for <em>in vivo</em> data, while utilizing significantly fewer signals compared to 2D-FT. The results demonstrate that the PL-SWE method also outperforms the PG method. For the viscoelastic phantoms, the mean RMSPE values using PL-SWE ranged from 2.61% to 4.29%, while the PG method produced RMSPE values between 3.56% and 15%. In the case of <em>in vivo</em> data, PL-SWE yielded RMSPE values between 7.01% and 7.68%, while PG results ranged from 17% to 418%. These findings highlight the superior accuracy and reliability of the PL-SWE method, particularly when compared to the PG approach. Our tests demonstrate that PL-SWE can effectively measure the phase velocity of both elastic and viscoelastic materials and tissues using a limited number of signals.</div><div>Utilizing a minimal number of spatial measurement points could enable accurate assessments even in cases with restricted field of view, thereby expanding the applicability of SWE across various patient populations.</div></div>","PeriodicalId":23522,"journal":{"name":"Ultrasonics","volume":"148 ","pages":"Article 107566"},"PeriodicalIF":3.8,"publicationDate":"2025-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143012606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of interfacial properties in a two-layered plate using quasi-static component generation during primary Lamb wave propagation","authors":"Han Chen ,&nbsp;Caibin Xu ,&nbsp;Guangjian Gao ,&nbsp;Yan Chen ,&nbsp;Yunshan Bai ,&nbsp;Mingxi Deng","doi":"10.1016/j.ultras.2025.107567","DOIUrl":"10.1016/j.ultras.2025.107567","url":null,"abstract":"<div><div>This study delves into the feasibility of leveraging quasi-static component (QSC) generation during primary Lamb wave propagation to discern subtle alterations in the interfacial properties of a two-layered plate. Unlike the second-harmonic generation of Lamb waves, QSC generation doesn’t necessitate precise phase-velocity matching but rather requires an approximate matching of group velocities to ensure the emergence of cumulative growth effects. This unique characteristic empowers the QSC-based nonlinear ultrasonic method to effectively surmount the limitations associated with inherent dispersion and multimode traits of Lamb wave propagation. Modeling the QSC generation reveals that the integrated amplitude of the QSC pulse, derived from the propagation of the primary Lamb wave tone burst, progressively amplifies with increasing propagation distance. Finite element simulations illustrate an overall decline in the efficiency of QSC generation amidst interfacial degradation. Experimental outcomes obtained via a nonlinear ultrasonic measurement-based setup vividly showcase the cumulative growth effect of QSC generation, evident with the propagation distance under approximate group velocity matching. To substantiate the influence of interfacial properties on QSC generation efficiency, varying thermal fatigue durations under cyclic temperature conditions are employed to simulate subtle changes in the two-layered plate’s interfacial properties. The relative nonlinear acoustic parameter exhibits a distinctly sensitive and monotonically decreasing behavior with escalating thermal fatigue durations, corroborating the impact of alterations in interfacial properties on QSC generation efficiency. The alignment between experimental findings and numerical analysis predictions suggests that the effect of QSC generation in primary Lamb wave propagation provides a promising means for sensitively assessing the early-stage degradation of interfacial properties in layered plates.</div></div>","PeriodicalId":23522,"journal":{"name":"Ultrasonics","volume":"148 ","pages":"Article 107567"},"PeriodicalIF":3.8,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142972366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Focal volume reduction in transcranial focused ultrasound using spherical wave expansions","authors":"Fei Shen ,&nbsp;Fan Fan ,&nbsp;Fengji Li ,&nbsp;Yue Wang ,&nbsp;Eleanor Martin ,&nbsp;Haijun Niu","doi":"10.1016/j.ultras.2025.107564","DOIUrl":"10.1016/j.ultras.2025.107564","url":null,"abstract":"<div><div>Transcranial focused ultrasound (tFUS) has been gaining increased attention as a non-invasive modality for treating brain diseases. However, accurately focusing on brain structures remains a challenge as the ultrasound is severely distorted by the presence of the skull. In this article, we propose a promising distortion correction method based on spherical wave expansions. It is demonstrated that the focal gain is directly related to the zero-order spherical harmonic coefficient, and suppressing higher-order coefficients significantly reduces the focal volume. Simulation results show that this method can correct distortion and effectively balance focal gain and volume, achieving a smaller focal spot with lower grating lobes compared to the commonly used time reversal technique. We also verified the capability of shifting the focal position in real time without additional simulations. This work provides an effective approach for tFUS treatments, offering enhanced precision and reduced focal volume.</div></div>","PeriodicalId":23522,"journal":{"name":"Ultrasonics","volume":"148 ","pages":"Article 107564"},"PeriodicalIF":3.8,"publicationDate":"2025-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142972367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ultrasound modulation of melatonin release from pineal glands in vitro","authors":"Alexis Carmine ,&nbsp;Bridget Thorpe ,&nbsp;Mallory Brayer ,&nbsp;Karun Sharma ,&nbsp;Aleksandar Jeremic ,&nbsp;Vesna Zderic","doi":"10.1016/j.ultras.2025.107565","DOIUrl":"10.1016/j.ultras.2025.107565","url":null,"abstract":"<div><h3>Objectives</h3><div>In this study, we aim to investigate whether therapeutic ultrasound can modulate the release of melatonin from the pineal gland—either increasing or decreasing its levels—and to assess the safety of this technique. This research could address a significant clinical need by providing a noninvasive method to potentially regulate sleep and circadian rhythms through the targeted modulation of melatonin.</div></div><div><h3>Methods</h3><div>Rat pineal glands were placed in a well with a Krebs Ringer Buffer solution.</div><div>Ultrasound was applied to the glands using unfocused transducers set at an average intensity of 1 W/cm² and three different frequencies (400, 600, and 800 kHz) with continuous exposure for 5 min. Fluid samples were collected from the well before (t = 0 min), immediately after (t = 5 min), and 30 min post-ultrasound treatment (t = 30 min). Melatonin release was subsequently measured using an ELISA kit and analyzed statistically. In addition, histological analysis was completed to determine any structural abnormalities due to ultrasound application.</div></div><div><h3>Results</h3><div>In the 600 kHz group there was a statistically significant decrease from t = 0 min to t = 5 min. No other statistically significant differences were observed. In addition, no histological changes were observed in the pineal glands due to ultrasound application.</div></div><div><h3>Conclusions</h3><div>This study indicated that ultrasound may be able to modulate melatonin release, however follow-up studies are necessary to determine optimal ultrasound parameters for this application.</div></div>","PeriodicalId":23522,"journal":{"name":"Ultrasonics","volume":"148 ","pages":"Article 107565"},"PeriodicalIF":3.8,"publicationDate":"2025-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143093968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Guided wave tomography of pipe bends based on full waveform inversion","authors":"Carlos-Omar Rasgado-Moreno ,&nbsp;Marek Rist ,&nbsp;Raul Land ,&nbsp;Madis Ratassepp","doi":"10.1016/j.ultras.2024.107560","DOIUrl":"10.1016/j.ultras.2024.107560","url":null,"abstract":"<div><div>Pipe bends are recognized as critical areas susceptible to wall thinning, a phenomenon instigated by abrupt changes in the fluid flow direction and velocity. Conventional monitoring techniques for bends typically depend on localized ultrasonic measurements of thickness. While these methods are effective, they can be time-consuming compared to the use of permanently installed transducers, a strategy employed in guided wave tomography (GWT). GWT provides the advantage of identifying and quantifying damage within a specified area by processing waves that are both generated and received by a set of transducers. In this study, we implement a GWT method based on full waveform inversion (FWI) for a high-resolution thickness reconstruction of a steel pipe bend. The wavefield in the bend section, made artificially anisotropic, is modeled using Thomsen parameters in the two-dimensional domain. This enhances its integration with the FWI algorithm. A numerical investigation was conducted to evaluate the efficacy of FWI in the presence of a defect as a function of its circumferential position. Additionally, an experimental evaluation was performed to reconstruct a defect artificially created on a pipe bend with a diameter (d) of 220 mm and a bend radius of 1.5d, and a defect with a diameter of 100 mm and a depth of 47%. The results indicate that the FWI method can effectively reconstruct the thickness map of smooth defects, regardless of their location, and it is particularly effective for defects situated closer to the extrados position.</div></div>","PeriodicalId":23522,"journal":{"name":"Ultrasonics","volume":"148 ","pages":"Article 107560"},"PeriodicalIF":3.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142955516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Overfit detection method for deep neural networks trained to beamform ultrasound images","authors":"Jiaxin Zhang ,&nbsp;Muyinatu A. Lediju Bell","doi":"10.1016/j.ultras.2024.107562","DOIUrl":"10.1016/j.ultras.2024.107562","url":null,"abstract":"<div><div>Deep neural networks (DNNs) have remarkable potential to reconstruct ultrasound images. However, this promise can suffer from overfitting to training data, which is typically detected via loss function monitoring during an otherwise time-consuming training process or via access to new sources of test data. We present a method to detect overfitting with associated evaluation approaches that only require knowledge of a network architecture and associated trained weights. Three types of artificial DNN inputs (i.e., zeros, ones, and Gaussian noise), unseen during DNN training, were input to three DNNs designed for ultrasound image formation, trained on multi-site data, and submitted to the Challenge on Ultrasound Beamforming with Deep Learning (CUBDL). Overfitting was detected using these artificial DNN inputs. Qualitative and quantitative comparisons of DNN-created images to ground truth images immediately revealed signs of overfitting (e.g., zeros input produced mean output values <span><math><mo>≥</mo></math></span>0.08, ones input produced mean output values <span><math><mo>≤</mo></math></span>0.07, with corresponding image-to-image normalized correlations <span><math><mo>≤</mo></math></span>0.8). The proposed approach is promising to detect overfitting without requiring lengthy network retraining or the curation of additional test data. Potential applications include sanity checks during federated learning, as well as optimization, security, public policy, regulation creation, and benchmarking.</div></div>","PeriodicalId":23522,"journal":{"name":"Ultrasonics","volume":"148 ","pages":"Article 107562"},"PeriodicalIF":3.8,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142923348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}