Radiation Physics and Chemistry最新文献

{"title":"Hydrogen generators in medical cyclotrons: A preliminary evaluation","authors":"Elena Miñana Olmo,&nbsp;Tomás Chivato Martín-Falquina","doi":"10.1016/j.radphyschem.2025.112668","DOIUrl":"10.1016/j.radphyschem.2025.112668","url":null,"abstract":"<div><div>Positron Emission Tomography (PET) has witnessed significant advances in radiopharmaceuticals and imaging technology, broadening its applications across oncology, neurology, and cardiology. PET radiopharmaceuticals are predominantly produced in cyclotrons. Hydrogen, a key element in cyclotron operation, is traditionally supplied via gas cylinders, posing challenges in purity, safety, and handling. This study evaluates the feasibility of using a hydrogen generator to supply high-purity hydrogen (grade 7.0) to a cyclotron's ion source (IS) for fluorine-18 production. A hydrogen generator was integrated with a PETtrace 880 cyclotron, and its performance was compared to conventional hydrogen cylinders across 34 irradiation runs of varying batch sizes. Results indicate that the test achieved consistent activity yields, stable hydrogen flow, and required lower arc current in the IS per unit of beam current, indicating higher efficiency. Additionally, the hydrogen generator offers safety benefits by minimizing high-pressure gas storage. While the device requires higher initial investment, its operational simplicity and potential to extend IS lifespan make it a viable alternative. Further studies are recommended to assess long-term impact and performance.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"232 ","pages":"Article 112668"},"PeriodicalIF":2.8,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143580726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"ANN-driven unfolding of epithermal neutron spectra in variable-geometry beam-shaping assemblies","authors":"S. Bedenko ,&nbsp;S. Polozkov ,&nbsp;G. Vlaskin ,&nbsp;N. Ghal-Eh ,&nbsp;F. Rahmani ,&nbsp;D. Veretennikov ,&nbsp;S. Bagherzadeh-Atashchi","doi":"10.1016/j.radphyschem.2025.112666","DOIUrl":"10.1016/j.radphyschem.2025.112666","url":null,"abstract":"<div><div>To study the risks associated with neutron fields from various sources, direct measurements using advanced detection technologies are essential. This study explores the Thermal Neutron Imaging System (TENIS) for characterizing the energy spectrum of an (α, n) neutron beam generated in the collimated channel of the Prizm-AN facility utilizing an IBN-10 source. We present the performance characteristics of the neutron beam, the permissible operational duration near the installation, a comprehensive map of thermal neutron flux parameters, and the results of spectrum unfolding achieved using artificial neural networks (ANNs). Our analysis confirms that TENIS can effectively measure the energy spectrum of slowed-down (α, n) neutrons produced under horizontal collimation. Additionally, we highlight the similarities between ^2,3H fusion and (α, n) reactions, integrating the Prizm-AN complex with TENIS as a powerful tool for the real-time monitoring and control of plasma parameters within the paired plasma source neutrons (PSN) and variable-geometry beam-shaping assembly (vBSA) system.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"232 ","pages":"Article 112666"},"PeriodicalIF":2.8,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143580376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Differences in shapes of nanometric pores synthesized in olivine by swift heavy ion irradiation and etching along various crystal axes","authors":"Sergey Gorbunov ,&nbsp;Mikhail Gorshenkov ,&nbsp;Galina Kalinina ,&nbsp;Natalia Polukhina ,&nbsp;Alexander Volkov ,&nbsp;Ruslan Rymzhanov","doi":"10.1016/j.radphyschem.2025.112675","DOIUrl":"10.1016/j.radphyschem.2025.112675","url":null,"abstract":"<div><div>Recent atomic-scale simulations of swift heavy ion track etching in olivine predicted formation of nanopores with non-circle cross sections which shape may be controlled by the irradiated crystal orientation relative to the beam direction. Taking this into account, we developed a technique of such nanopores synthesis based on the precise etching time control. The approach includes the following steps: (a) orientation of the crystal relative to the SHI beam and irradiation; (b) selection of the track etching time most favorable for production of the pores with required dimensions; (c) removal of the surface layer containing etching pits in order to study the shape of narrow pores in the bulk. The atomic force and scanning electron microscopy confirm appearance of narrow polygonal channels in the irradiated and etched olivine crystals, which shapes depend on the crystallographic orientation.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"232 ","pages":"Article 112675"},"PeriodicalIF":2.8,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143580723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Optimizing minibeam collimator design for enhancing normal tissue sparing in ocular tumour proton therapy","authors":"Tsz-Yui Chan ,&nbsp;Chien-Yu Lin ,&nbsp;Shen-Hao Lee ,&nbsp;Jiunn-Woei Liaw ,&nbsp;Tsi-Chian Chao ,&nbsp;I-Chun Cho","doi":"10.1016/j.radphyschem.2025.112674","DOIUrl":"10.1016/j.radphyschem.2025.112674","url":null,"abstract":"<div><div>Uveal melanoma, the most common primary intraocular tumour in adults, presents significant therapeutic challenges due to its aggressive nature and the potential for severe treatment-related complications, including vision loss. Achieving effective tumour control while minimizing damage to surrounding healthy tissues remains a critical goal in radiotherapy. Proton minibeam radiotherapy (pMBRT), an advanced form of spatially fractionated radiotherapy (SFRT), has emerged as a promising approach to address these challenges.</div><div>pMBRT employs a mechanical collimator to spatially fractionate a broad proton beam into multiple narrow beamlets, creating a dose distribution with high-dose peaks and low-dose valleys in shallow regions. As the beamlets travel deeper into tissue, multiple Coulomb scattering facilitates their convergence, resulting in a uniform dose at the tumour target.</div><div>This study systematically optimized the collimator design by evaluating various geometries and materials, specifically brass and polylactic acid (PLA). Simulations of dose distributions were performed using the Tool for Particle Simulation (TOPAS) and validated through experimental measurements with Gafchromic films. Results indicated that brass collimators, with their high atomic number, produced sharper dose profiles and higher peak-to-valley dose ratios (PVDR), demonstrating superior spatial dose modulation. Conversely, PLA collimators yielded smoother dose profiles and lower secondary dose contributions, showcasing their potential for reducing collateral tissue damage.</div><div>The optimized collimator design, featuring a 0.8 mm slit width and a 1 mm spacing, achieved an ideal balance between maximizing PVDR and ensuring uniform beam recombination at the target depth. These findings underscore the potential of tailored collimator designs to enhance the therapeutic precision of pMBRT, offering improved tumour control with minimized impact on healthy tissues. This study provides a foundation for further advancements in collimator technology and its clinical applications in treating uveal melanoma and other challenging tumour sites.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"232 ","pages":"Article 112674"},"PeriodicalIF":2.8,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143553025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Exploration of the gamma-ray shielding capabilities of tungsten oxide and chromium-infused silicone rubber composites","authors":"B.P. Srilakshmi ,&nbsp;A. Jagannatha Reddy ,&nbsp;M.R. Ambika ,&nbsp;Sherry Shajan Kuttukaran ,&nbsp;Yeshwanth H. Reddy ,&nbsp;N. Nagaiah ,&nbsp;D.N. Deepika ,&nbsp;Kalappa Prashantha","doi":"10.1016/j.radphyschem.2025.112661","DOIUrl":"10.1016/j.radphyschem.2025.112661","url":null,"abstract":"<div><div>Gamma rays are highly energetic type of ionizing radiation important in medical diagnostics, which requires effective protective measures. Polymers reinforced with appropriate fillers can offer excellent radiation shielding properties comparable to conventional materials. This study investigates the gamma radiation shielding efficiency of silicone rubber reinforced with tungsten oxide (WO₃) and chromium (Cr). Composites with fixed 30 phr WO₃ and varying Cr concentrations (10–70 phr) were fabricated and characterized. Field Emission Scanning Electron Microscopy with Energy Dispersive X-ray spectroscopy (FESEM/EDX) confirmed uniform filler dispersion, while FTIR showed no significant chemical changes. X-ray diffraction (XRD) analysis revealed average crystallite sizes of 11–32 nm (Scherrer's formula) and 16–39 nm (Williamson-Hall plot). The mechanical properties were explored using a Universal Testing Machine (UTM), revealing that an increase in filler content correlated with enhanced tensile strength and hardness. Gamma attenuation studies (using Cs-137 and Ba-133 sources) revealed the excellent efficiency of the composite with 30 phr WO₃ and 50 phr Cr (3WO5C) with Mass Attenuation Coefficients (MAC) increasing from 1.45, 0.202, and 0.103 cm²/g to 1.57, 0.258, and 0.129 cm²/g, and half-value layer (HVL) thickness decreasing from 0.356, 2.551, and 6.722 cm to 0.269, 1.642, and 5.366 cm, for gamma energies 80, 356 and 662 keV respectively. Critically, these composites are significantly lighter than lead, offering improved shielding performance at a reduced weight.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"232 ","pages":"Article 112661"},"PeriodicalIF":2.8,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143552776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Self-attenuation effect correction methods employed for gamma-ray spectrometry: A critical review study","authors":"A. Barba-Lobo","doi":"10.1016/j.radphyschem.2025.112665","DOIUrl":"10.1016/j.radphyschem.2025.112665","url":null,"abstract":"<div><div>The usage of gamma-ray spectrometry has become generalized due to several important advantages that offers versus other radiometric techniques such as alpha-particle spectrometry or liquid scintillation counting. When using gamma-ray spectrometry, the full-energy peak efficiency, FEPE, must be accurately and precisely obtained for a wide range of sample chemical compositions, apparent densities and thicknesses, as well as geometries and energies. For this, the self-attenuation effect corrections must be properly applied for each case in order to transform the calibration sample FEPE into problem sample FEPE. Nowadays, different experimental and simulated methodologies such as Cutshall and Appleby models, and LabSOCS, EFFTRAN, DETEFF, PENELOPE and Geant4, respectively, are generally applied to obtain the problem sample FEPE. However, in many cases, self-attenuation effect corrections can be not properly applied. For this reason, the aim of this study is to comprehensively critical review many different experimental and simulated methodologies usually used to apply self-attenuation effect corrections, offering exhaustive discussions about their proper use as well as proposals to improve many different aspects related to them, and making deep comparisons among their advantages and disadvantages. Moreover, an exhaustive comparison among FEPEs obtained using experimental and simulated methodologies was addressed. In the case of the sample pretreatment, this study also offers a wide discussion of many aspects related to their homogenization process regarding the chemical composition and compaction. In addition, the proper selection of the multielement technique for the major element concentrations is also widely discussed in this study, where an accurate measurement of major element concentrations is essential to properly obtain the sample mass attenuation coefficient which is needed to apply self-attenuation effect corrections.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"232 ","pages":"Article 112665"},"PeriodicalIF":2.8,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Comprehensive characterization of proton pencil beam profiles using a novel couch-mounted 2D strip detector system","authors":"Hsiao-Chieh Huang ,&nbsp;Hsien-Hsin Chen ,&nbsp;Chih-Hsun Lin ,&nbsp;Fu-Xiong Chang ,&nbsp;Wei-Heng Kao ,&nbsp;Po-Jui Chen ,&nbsp;Tsi-Chian Chao","doi":"10.1016/j.radphyschem.2025.112663","DOIUrl":"10.1016/j.radphyschem.2025.112663","url":null,"abstract":"<div><div>Proton therapy has gained prominence in recent years, with over 300,000 patients treated worldwide using advanced techniques like pencil beam scanning (PBS). Accurate measurement of proton beam characteristics is crucial for optimizing treatment plans and ensuring patient safety. This study introduces a novel two-dimensional strip detector system, CROSS, integrated with a programmable couch mount, designed to evaluate proton beam properties across various gantry angles. The CROSS detector's performance was validated through comparisons with a pinpoint chamber, Gafchromic EBT3 film, and the XRV-124 detector. Spot size measurements showed a slight increase compared to the pinpoint chamber, with average deviations of 11.3% in the Y-direction and 6.3% in the X-direction. Spot position accuracy tests demonstrated excellent agreement with EBT3 film, with an average positional deviation of 0.11 ± 0.06 mm, and all deviations remaining within 0.2 mm. The beam characteristics across different gantry angles showed maximum spot size variations of 0.17 mm in the Y-axis and 0.11 mm in the X-axis. Proton isocenter measurements with CROSS were largely consistent with XRV-124, with deviations under 0.2 mm in most cases, except for gantry angles of 90° and 315°, where deviations of 0.25 mm and 0.33 mm were observed. These findings highlight the CROSS detector's precision and versatility, making it a valuable tool for quality assurance in proton therapy.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"232 ","pages":"Article 112663"},"PeriodicalIF":2.8,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143552779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Effect of electron beam irradiation on properties of EVA/HDPE blends with intumescent flame retardants","authors":"Sangwon Park ,&nbsp;Hyun-Rae Kim ,&nbsp;Sang-Yun Kang ,&nbsp;Seung-Tae Jung ,&nbsp;Young-Chang Nho ,&nbsp;Jong-Seok Park ,&nbsp;Byoung-Min Lee ,&nbsp;Jae-Hak Choi","doi":"10.1016/j.radphyschem.2025.112664","DOIUrl":"10.1016/j.radphyschem.2025.112664","url":null,"abstract":"<div><div>Conventional thermoplastics are widely used as insulating materials in various industrial fields, but various research efforts are being conducted to improve their thermal stability and flame retardancy. In this study, poly(ethylene-co-vinyl acetate) (EVA)/high-density polyethylene (HDPE)/intumescent flame retardants (IFRs) blends were prepared, and changes in properties were investigated according to the IFRs contents and electron beam irradiation conditions. As the content of IFRs increased, the flame retardancy of the blends improved significantly, but mechanical properties deteriorated. Mechanical properties, thermal stability, and flame retardancy were enhanced by electron beam irradiation, attributed to the formation of crosslinked network structures. UL-94 vertical tests results revealed that blends containing more than 50 g of IFRs and irradiated at 100 kGy exhibited a UL-94 V-0 rating. Therefore, the EVA/HDPE/IFRs blends prepared in this study can be applied as insulating materials with excellent thermal stability, mechanical properties, and flame retardancy.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"232 ","pages":"Article 112664"},"PeriodicalIF":2.8,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143552780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Positron driven molecular processes for H2CO, NO2 and HCN","authors":"Neha Barad,&nbsp;Smruti Parikh,&nbsp;Chetan Limbachiya","doi":"10.1016/j.radphyschem.2025.112643","DOIUrl":"10.1016/j.radphyschem.2025.112643","url":null,"abstract":"<div><div>In this work, we report results of comprehensive study of positron driven molecular chemistry for planetary compounds, H₂CO, NO₂ and HCN. All these molecules are highly polar in nature making the positron-molecule interaction more sensitive to polarization potential at lower energies. We have employed a novel approach to construct the polarization potential that takes Positron Correlation Polarization (PCP) to determine the energy independent cut-off thereby properly accounting for the short range effects. We have quantified various molecular processes initiated due to positron interaction by evaluating elastic (<span><math><mrow><msub><mi>Q</mi><mrow><mi>e</mi><mi>l</mi></mrow></msub></mrow></math></span>), inelastic (<span><math><mrow><msub><mi>Q</mi><mrow><mi>i</mi><mi>n</mi><mi>e</mi><mi>l</mi></mrow></msub></mrow></math></span>), direct ionization (<span><math><mrow><msub><mi>Q</mi><mrow><mi>D</mi><mo>−</mo><mi>i</mi><mi>o</mi><mi>n</mi></mrow></msub></mrow></math></span>), positronium formation (<span><math><mrow><msub><mi>Q</mi><mrow><mi>P</mi><mi>s</mi></mrow></msub></mrow></math></span>), total ionization (<span><math><mrow><msub><mi>Q</mi><mrow><mi>i</mi><mi>o</mi><mi>n</mi></mrow></msub></mrow></math></span>) and total cross-sections (<span><math><mrow><msub><mi>Q</mi><mrow><mi>t</mi><mi>o</mi><mi>t</mi></mrow></msub></mrow></math></span>) for the wide energy span from circa 1 eV–5000 eV using modified Spherical Complex Optical Potential (SCOP) method. Positron driven ionization is investigated using Complex Scattering Potential – ionization contribution (CSP-ic) method. In this work, positronim formation and direct ionization channels are reported for the first time, except for H₂CO. This study aims to find probabilities for different positron assisted processes for these molecules using the quantum chemical treatment that can contribute to improve various models of atmospheric chemistry.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"232 ","pages":"Article 112643"},"PeriodicalIF":2.8,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143553012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Synthesis, structural, linear/nonlinear optical properties, and radiation shielding potential of iron silicate (Fe2SiO4) nanoparticles for multi-functional applications","authors":"Ahmed M. Hassan ,&nbsp;B.M. Alotaibi ,&nbsp;Ahmed S. Ali ,&nbsp;Shams A. M. Issa ,&nbsp;Hesham M.H. Zakaly","doi":"10.1016/j.radphyschem.2025.112619","DOIUrl":"10.1016/j.radphyschem.2025.112619","url":null,"abstract":"<div><div>In this study, Fe-doped SiO₂ nanoparticles (Fe–SiO₂ NPs) were synthesized using the sol-gel method to investigate their structural, and linear/nonlinear optical attributes as well as radiation shielding properties. The doping levels of Fe ranged from 0% to 12%. The X-ray diffraction (XRD) analysis confirmed the hexagonal structure of the SiO₂ matrix with the incorporation of a iron silicate cubic phase (Fe₂SiO₄) and minor peaks of monoclinic Fe₂O₃. With increasing Fe concentrations, the crystallite size increased from 39 nm to 48 nm, while lattice strain and dislocation density decreased. The optical measurements revealed a red shift in the absorption spectra with Fe doping, and the bandgap decreased from 5.65 eV for undoped SiO₂ to 5.26 eV for SOF-12. Nonlinear optical properties were significantly enhanced with Fe doping, as evidenced by the third-order nonlinear susceptibility (χ³) increased by more than double as Fe concentrations increased. Additionally, the nonlinear refractive index (n₂) exhibited a sharp increase with Fe content, indicating potential for nonlinear photonic applications. Radiation shielding assessments revealed a mass attenuation coefficient of 10.987 cm²/g at 0.015 MeV and a half-value layer of 3.36 cm at 1 MeV for the 12% Fe-doped sample (SOF-12), demonstrating superior lightweight shielding efficiency compared to conventional materials. These results demonstrate that Fe-doped SiO₂ NPs possess favorable structural and optical characteristics, making them promising candidates for applications in optoelectronics, radiation shielding, and photonic devices.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"232 ","pages":"Article 112619"},"PeriodicalIF":2.8,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143553011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}