Acta Astronautica最新文献

{"title":"Attitude control and online estimation of unknown mass properties for captured debris with a flexible spacecraft","authors":"Nicolo Woodward,&nbsp;Riccardo Bevilacqua","doi":"10.1016/j.actaastro.2025.03.007","DOIUrl":"10.1016/j.actaastro.2025.03.007","url":null,"abstract":"<div><div>With more spacecraft launched in Low Earth Orbit (LEO) for educational and research purposes, their mission completion or mission failure results in an increasing number of inactive orbiting space bodies. These uncooperative bodies can lead to collision with other space systems, creating the need to actively remove debris for collision avoidance and to increase the availability of orbital slots. Solutions currently investigated see the use of robust control in robot manipulators and tethered nets to maneuver a main spacecraft and the attached unknown debris. Another solution is to employ cameras and a combination of image processing technologies and output feedback to estimate the inertia tensor of the space debris to then employ it in a model-based controller architecture. However, robust control techniques and vision-based estimation suffer from practical disadvantages, like the added complexity in the Reaction Control System (RCS) with extra onboard fuel for the former, and the added complexity in computer resources and extra sensors for the latter. In this investigation, an adaptive attitude controller for a spacecraft debris collector is proposed. The adaptive control law uses Integral Concurrent Learning (ICL) to learn, onboard, the mechanical properties of an unknown spacecraft target using measurements of the states of the system already available onboard. During the collection of the system states and inputs, a classic adaptive controller is implemented to guarantee bounded stability of the system. Through numerical simulations of a test-case scenario, it is shown asymptotic convergence of both the attitude tracking error and the estimation error of the unknown parameters of the captured debirs and the flexible appendage. The results are compared to the system response of a classic adaptive controller that does not include ICL to show the improvements in performance ICL brings to the attitude maneuvering.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"232 ","pages":"Pages 191-203"},"PeriodicalIF":3.1,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143681897","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":"Helix orbit deployment of nanosatellites for formation flight","authors":"Debdeep Roychowdhury ,&nbsp;Sebastian Grau ,&nbsp;Enrico Stoll","doi":"10.1016/j.actaastro.2025.02.035","DOIUrl":"10.1016/j.actaastro.2025.02.035","url":null,"abstract":"<div><div>This study aimed to deploy two nanosatellites from Technische Universität Berlin, within the scope of the NanoFF mission, directly into a helix orbit using currently available technology to minimize collision risk post-deployment. The methodology involved using D-Orbit’s ION orbital transfer vehicle, launched aboard SpaceX’s Falcon 9 launcher, for the precise deployment of the NanoFF satellites. The planned deployments with ION, equipped with capabilities for multiple satellite deployments, faced operational constraints such as concerns from SpaceX impacting the timing of the second deployment, and the inability to deploy near the North Pole due to attitude accuracy concerns. Deployment vectors were carefully planned and adjusted for both deployments to minimize collision risk. In-orbit data from ION and the NanoFF satellites, including Global Navigation Satellite System data and Two-Line-Elements, were analyzed to compare the estimated versus requested deployment vectors. The results were analyzed to check discrepancies, discuss lessons learned, and suggest improvements in deployment strategies to enhance future formation flying missions.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"232 ","pages":"Pages 244-257"},"PeriodicalIF":3.1,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143698027","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":"Autonomous shape modeling of small bodies using infrared image silhouettes","authors":"Koundinya Kuppa ,&nbsp;Jay W. McMahon ,&nbsp;Ann B. Dietrich","doi":"10.1016/j.actaastro.2025.03.005","DOIUrl":"10.1016/j.actaastro.2025.03.005","url":null,"abstract":"<div><div>Missions to small bodies require accurate shape characterization for navigation and scientific purposes. In this paper, a Shape from Silhouette (SfS) algorithm is presented which uses the visual extents of the body (silhouettes) in a set of infrared images to infer its three-dimensional shape. The algorithm leverages intersections between rays (each corresponding to a silhouette pixel) from different images to extract the small body shape. A novel sampling method is introduced to optimally extract the relevant silhouette pixels from each image that provide salient information to the shape modeling process. This reduces the computational burden of the algorithm while preserving the salient shape information from each image. The use of infrared images ensures the robustness of the algorithm to lighting geometries. The SfS algorithm is applied to synthetic images of four small bodies at two different approach latitudes of 0° and 45°. At a 0° approach latitude, the resultant shape models have an RMS error of 1.333 m, 4.056 m, 53.99 m, 341.6 m for Bennu, Itokawa, 67P/C-G, and Eros respectively. At a 45° approach latitude, the resultant shape models have an RMS error of 3.159 m, 4.672 m, 54.27 m, 217.1 m for Bennu, Itokawa, 67P/C-G, and Eros respectively. The algorithm’s sensitivity to pole errors (of <span><math><mrow><mn>2</mn><mo>−</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>∘</mo></mrow></msup></mrow></math></span>) is characterized for the four bodies which shows an expected degradation in performance as the error increases. The degradation is worse for Itokawa, 67P/C-G, and Eros compared to Bennu due to their more irregular shape. The algorithm is also applied to real infrared images taken by the TIR camera on-board the Hayabusa2 spacecraft to generate a shape model of asteroid Ryugu. The RMS error of this shape model is 8.652 m. This algorithm can be used in future missions such as HERA and Hayabusa2<span><math><mi>♯</mi></math></span> to obtain initial shape models of the target objects using on-board infrared images.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"232 ","pages":"Pages 215-230"},"PeriodicalIF":3.1,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143681899","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":"Rigid–flexible coupling dynamics modeling and fractional-order sliding mode control for large space solar power stations","authors":"Shuo Han ,&nbsp;Haoyi Wang ,&nbsp;Feng Gao ,&nbsp;Weiran Yao ,&nbsp;Guanghui Sun ,&nbsp;Xiangyu Shao","doi":"10.1016/j.actaastro.2025.03.006","DOIUrl":"10.1016/j.actaastro.2025.03.006","url":null,"abstract":"<div><div>Precise on-orbit assembly of Space Solar Power Station imposes great challenges on its effective rigid–flexible coupling dynamics modeling and low vibration control. This paper presents an integrated framework combining a reduced-order dynamics model and an improved fractional-order controller of Space Solar Power Station. The dynamics model, developed through Lagrangian equations and finite element methods, reduces system complexity from tens of thousands to tens of degrees of freedom while preserving essential dynamic properties. The fractional-order controller is proposed on this foundation, containing a robust fractional-order sliding surface for chattering suppression and the super-twisting algorithm for uncertainty and disturbance rejection. Simulations of three critical assembly phases are conducted to demonstrate the closed-loop behavior, simulation results show significant improvements in convergence time (reductions ranging from 44.6% for truss docking to 78.2% for antenna adjustment) and vibration suppression (vibration mode peaks decrease from 49 to 9 for <span><math><msub><mrow><mi>η</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span> and 65 to almost 0 for <span><math><msub><mrow><mi>η</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span>) compared to the PID controller, verifying the effectiveness of the proposed control strategy.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"232 ","pages":"Pages 164-173"},"PeriodicalIF":3.1,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143637187","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":"A validation framework for orbit uncertainty propagation using real satellite data applied to orthogonal probability approximation","authors":"Pugazhenthi Sivasankar ,&nbsp;Bennie G. Lewis Jr. ,&nbsp;Austin B. Probe ,&nbsp;Tarek A. Elgohary","doi":"10.1016/j.actaastro.2025.02.034","DOIUrl":"10.1016/j.actaastro.2025.02.034","url":null,"abstract":"<div><div>This paper presents a validation framework using data for uncertainty propagation techniques for space situational awareness (SSA) applications. In particular, we validate a novel technique for uncertainty propagation, dubbed here as Orthogonal Probability Approximation (OPA) This technique describes the evolution of state/parameter uncertainties, e.g. initial condition and/or drag coefficient, of nonlinear dynamical systems at a future time. This new uncertainty quantification method employs Liouville’s theorem and Chebyshev polynomial approximation to create a functional representation of the probability density function (PDF) at the future time of interest at a fraction of the computational cost of classical high-fidelity uncertainty propagation methods. OPA is first compared against Polynomial Chaos Expansions and Monte-Carlo simulations to numerically demonstrate the accuracy of the method. For the real data validation, two sources of satellite data are used: GRACE navigation data from the Jet Propulsion Laboratory (JPL) database, and FireOPAL ground-based observer provided by Lockheed Martin. In the presented validation framework, the state/parameter uncertainties of resident space objects (RSOs) are propagated by OPA without using any measurements. The maximum likelihood estimate and the uncertainty bounds of the RSO state from OPA are compared with documented estimates and uncertainty bounds obtained from real satellite/object tracking data as well as other uncertainty propagation methods Results indicate successful validation using GRACE navigation data (precise orbit determination in LEO), and FireOPAL sensor tracking data for Yamal 202 (GEO case) and a rocket body of Block-DM satellite with highly elliptical orbit (HEO). The results show the capability of OPA to accurately estimate the states of RSOs in the absence of continuous measurements, and, in addition, the presented framework can be used to validate any uncertainty propagation technique.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"232 ","pages":"Pages 453-478"},"PeriodicalIF":3.1,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143768152","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":"Planetary protection trades and lessons learned from designing Mars Sample Return’s Capture, Containment, and Return System","authors":"Giuseppe Cataldo ,&nbsp;Bruno Sarli ,&nbsp;Peter Gage ,&nbsp;Todd White ,&nbsp;Brendan Feehan ,&nbsp;Fernando Pellerano","doi":"10.1016/j.actaastro.2025.01.046","DOIUrl":"10.1016/j.actaastro.2025.01.046","url":null,"abstract":"<div><div>This paper describes the trades carried out and lessons learned while performing the preliminary design of the Capture, Containment, and Return System as part of the Mars Sample Return campaign, before the re-architecture studies initiated after December 2023. Mars Sample Return is an effort to bring to Earth rock cores, regolith, and atmospheric samples from Mars inside sealed tubes. The importance of these samples lies in their potential to provide valuable information about Mars’ geological and climate evolution, its potential ability to have harbored life in the past, and the risks posed to future human exploration by the Martian environment. The trades and lessons learned presented in this paper refer to the preliminary design solutions generated in response to the constraints levied on the payload design by backward planetary protection requirements, which impose the protection of the Earth–Moon system from any potential negative effects the returned Mars material might cause. Topics include jettison of the payload capture enclosure, replacement of the aseptic transfer system with an ultraviolet illumination system, and leveraging different design options to augment the micrometeoroid protection system to improve shielding performance.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"232 ","pages":"Pages 174-180"},"PeriodicalIF":3.1,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143644701","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":"Guidance strategies to deploy a Lunar Navigation Constellation from Gateway","authors":"Edoardo Maria Leonardi,&nbsp;Giulio De Angelis,&nbsp;Mauro Pontani","doi":"10.1016/j.actaastro.2025.02.023","DOIUrl":"10.1016/j.actaastro.2025.02.023","url":null,"abstract":"<div><div>In recent years, lunar constellation design and deployment has attracted a strong interest from the scientific community and the major space agencies. Indeed, a similar space infrastructure will represent a valuable asset for navigation and telecommunications purposes, useful to many robotic and human activities on the lunar surface. This study focuses on the analysis, design, and testing of three different feedback guidance strategies for the deployment of a lunar constellation, starting from Gateway. Orbit dynamics is modeled in a high-fidelity framework that employs planetary ephemeris and includes all the relevant orbit perturbations, i.e. the gravitational attraction due to Earth and Sun and several harmonics of the selenopotential. A constellation composed of 6 satellites is considered. They travel two distinct frozen lunar elliptical orbits, with proper mutual phasing. The first deployment strategy assumes that each satellite uses high-thrust propulsion to enter its operational orbit, with correct phasing. To do this, a single-parameter iterative Lambert-based algorithm is proposed as an effective real-time guidance technique, capable of determining all the (modest) intermediate correction maneuvers, to drive each satellite toward the desired position. The second deployment strategy assumes again the use of high thrust, while including two distinct phases: (a) orbit acquisition and (b) phasing. Specifically, in phase (a) three satellites are arranged as a cluster and travel toward their orbit, leveraging an original two-parameter iterative Lambert-based guidance. In phase (b), each vehicle performs phasing maneuvers, to get its correct position. The third deployment strategy includes again two phases: (a) low-thrust orbit acquisition and (b) phasing. In phase (a), the satellites are clustered and embarked onboard two cargo spacecraft, equipped with a low-thrust propulsion system. Nonlinear orbit control allows identifying a saturated feedback law for the low thrust magnitude and direction, and is shown to be effective as a guidance technique for each cargo vehicle. The closed-loop dynamical system at hand is proven to enjoy quasi-global stability properties, leveraging the Lyapunov stability theory. In phase (b), each satellite performs again phasing maneuvers, as in the preceding strategy. The three deployment strategies are evaluated in both nominal and nonnominal flight conditions, with the intent of showing their effectiveness while comparing their performance, in terms of propellant consumption and overall deployment duration.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"232 ","pages":"Pages 143-153"},"PeriodicalIF":3.1,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620368","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":"Spray characteristics of gel containing nanoparticles in impinging jet injectors","authors":"Qiyou Liu ,&nbsp;Penghui Li ,&nbsp;Hu Sun ,&nbsp;Dingwei Zhang ,&nbsp;Bingqiang Ji ,&nbsp;Lijun Yang ,&nbsp;Qingfei Fu","doi":"10.1016/j.actaastro.2025.02.051","DOIUrl":"10.1016/j.actaastro.2025.02.051","url":null,"abstract":"<div><div>Atomization is one of the critical challenges in the application of nanoparticle–laden gel propellants due to their high viscosity and complex rheological properties. This study investigates the rheological properties and atomization characteristics of gel containing varying concentrations of nanoparticles in impinging jet injectors. The rheological behavior of the gels was measured to characterize their shear-thinning properties. Impinging jet injectors with different structural parameters were designed and tested to evaluate the spray images, droplet size distributions, and discharge coefficients under various particle concentrations and flow conditions. Comparative analysis between water and particle–laden gels revealed that the high viscosity and complex rheological properties of gels hinder atomization, resulting in larger droplet sizes and reduced discharge coefficients. The results show that higher particle concentrations exacerbate these effects, but optimized injector design and increased jet velocity can mitigate the challenges by enhancing shear rates and reducing apparent viscosity. This study provides insights into gel formulation and injector design, offering practical guidance for advancing the application of gel propellants in propulsion systems.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"232 ","pages":"Pages 94-102"},"PeriodicalIF":3.1,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143591509","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":"Comparison between direct and indirect measurements for externally wetted electrospray thruster with adapted analytical balance","authors":"Borja De Saavedra ,&nbsp;David Villegas-Prados ,&nbsp;Mick Wijnen ,&nbsp;Javier Cruz","doi":"10.1016/j.actaastro.2025.02.044","DOIUrl":"10.1016/j.actaastro.2025.02.044","url":null,"abstract":"<div><div>Ionic liquid electrospray propulsion systems are a promising technology for the rapidly growing small satellite market, potentially exhibiting high specific impulse and efficiency even at very low power. Direct performance characterization of electrospray thrusters is a challenging issue, given the low thrust and mass flow rate values. In this work, an analytical balance was modified for direct performance characterization of electrospray thrusters with sub-micronewton thrust uncertainty and sub-milligram-per-hour mass loss rate measurements. An electrostatic calibration device was built with commercial-off-the-shelf heat sinks as electrostatic combs, and characterized with high-precision calibration weights to correct the measurements of the balance in vacuum. The performance of an externally wetted electrospray thruster was obtained with simultaneous direct and indirect measurements by setting up the modified balance and a time-of-flight mass spectrometer in tandem. Direct thrust values of the order of <span><math><mi>μ</mi></math></span>N and in situ mass loss rates <span><math><mo>&lt;</mo></math></span> mg/h were consistently measured simultaneously. Thrust results concurred with indirect measurements with an average relative difference of 10.5%, showing a consistent ratio to the emitted current of <span><math><mrow><mo>≈</mo><mn>0</mn><mo>.</mo><mn>1</mn><mi>μ</mi></mrow></math></span>N/<span><math><mi>μ</mi></math></span>A. In contrast, the mass flow rate estimated from time-of-flight data was notably lower than the mass loss rate measured with the balance, with relative differences from −23.1% to −64.7%. Possible causes for this discrepancy and methods for their diagnosis are proposed.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"232 ","pages":"Pages 283-295"},"PeriodicalIF":3.1,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143704792","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":"Rigid-flexible coupled dynamics and configuration stability of maneuverable space tether net under impact loads","authors":"Mani Kakavand,&nbsp;Zheng H. Zhu","doi":"10.1016/j.actaastro.2025.02.031","DOIUrl":"10.1016/j.actaastro.2025.02.031","url":null,"abstract":"<div><div>This paper investigates the configuration stability and rigid–flexible coupled dynamics of maneuverable space tether nets under impact loads. To analyze the complex 3D maneuvers of the net, a geometric mechanics framework is developed, incorporating the rigid–flexible coupling between wave propagation in the net and the attitude dynamics of maneuvering satellites attached to its corners. A coordinate-free representation in Lie group is derived for the satellites’ attitude dynamics on <span><math><mrow><mi>SO</mi><mrow><mo>(</mo><mn>3</mn><mo>)</mo></mrow></mrow></math></span>. Equilibrium states, modal shapes, and chaotic behavior of the tether net are examined using the geometric Jacobian method, which reveals the coexistence of stiff tether dynamics and slow satellite attitude motions, leading to extreme disparities in time scales and makes numerical analysis challenging by conventional integration schemes. To solve the problem, a structure-preserving integrator is derived to accurately analyze the chaotic behavior of the net over extended periods. Dynamic responses to impact loads are analyzed under two initial conditions: (i) a slack net and (ii) a net tensioned by satellite control forces and torques. Numerical results reveal significant coupling effects between net deformation and satellite attitude motion, and even minor perturbations may lead to chaotic responses of the net indicated by Lyapunov exponents. Moreover, the pre-tension of the net by control forces from satellites can effectively suppress chaotic behaviors, leading to more stable configuration and controlled maneuvering. These findings offer critical insights into configuration stability and dynamics of maneuverable space tether nets, which will enable the effective control strategy development to suppress chaos and enhance net’s maneuverability in three-dimensional space.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"232 ","pages":"Pages 114-131"},"PeriodicalIF":3.1,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143591511","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}