Pub Date : 2025-11-04DOI: 10.1016/j.jqsrt.2025.109735
Yujia Sun , Chenxin Lin , Shu Zheng
Thermal radiation plays an important role in combustion systems due to its significant effect on the energy evolution. Radiation modeling in combustion simulations needs expensive computational resources due to high complexity of the radiative transfer equation and highly variations of the spectral radiative properties. Traditional numerical methods for the radiation modeling have many simplified and approximated models, but they are still suffering from the irreconcilable conflict between the accuracy and efficiency. This work investigates the capability of machine learning for predicting radiative heat transfer in combustion scenarios. Two machine learning models, UNet model and Fourier network operator (FNO) model are designed to learn radiative heat transfer directly from the temperature and concentrations fields. Their performances are tested for a turbulent diffusion flame. Results show that both UNet and FNO performs well for emulating the radiative heat source for the considered flame, with relative errors generally smaller than 0.3 %. The two models have similar accuracies. This study demonstrates the feasibility of using UNet and FNO models as surrogate model for non-gray gas radiative heat transfer in combustion system, but they need further investigations for more complex combustion scenarios.
{"title":"Emulating non-gray gas radiative heat transfer in combustion scenarios by machine learning method","authors":"Yujia Sun , Chenxin Lin , Shu Zheng","doi":"10.1016/j.jqsrt.2025.109735","DOIUrl":"10.1016/j.jqsrt.2025.109735","url":null,"abstract":"<div><div>Thermal radiation plays an important role in combustion systems due to its significant effect on the energy evolution. Radiation modeling in combustion simulations needs expensive computational resources due to high complexity of the radiative transfer equation and highly variations of the spectral radiative properties. Traditional numerical methods for the radiation modeling have many simplified and approximated models, but they are still suffering from the irreconcilable conflict between the accuracy and efficiency. This work investigates the capability of machine learning for predicting radiative heat transfer in combustion scenarios. Two machine learning models, UNet model and Fourier network operator (FNO) model are designed to learn radiative heat transfer directly from the temperature and concentrations fields. Their performances are tested for a turbulent diffusion flame. Results show that both UNet and FNO performs well for emulating the radiative heat source for the considered flame, with relative errors generally smaller than 0.3 %. The two models have similar accuracies. This study demonstrates the feasibility of using UNet and FNO models as surrogate model for non-gray gas radiative heat transfer in combustion system, but they need further investigations for more complex combustion scenarios.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"349 ","pages":"Article 109735"},"PeriodicalIF":1.9,"publicationDate":"2025-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145435107","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}
Pub Date : 2025-11-01DOI: 10.1016/j.jqsrt.2025.109723
I. Majdi , S. Harbaoui , D. Ben Abdallah , J. Salem , Z. Boussetta , F. Kwabia Tchana , X. Landsheere , A. Voute , M. Hochlaf , H. Aroui
In the present work, we measured the O2-broadening coefficients of the absorption lines in the ν2 and ν5 bands of methyl bromide at room temperature (T = 295 K) using a high-resolution Fourier Transform spectrometer. Eight spectra were recorded at pressures ranging from 2.0 to 6.5 Torr for the active gas and from 3 to 90 Torr for the perturber gas. The line shape parameters were obtained by fitting Voigt and Galatry profiles to the measured line shapes, allowing the determination of the O2-broadening coefficients for the branches over the 1250 – 1622 cm-1 wavenumbers range. This range covers 1451 measured transitions with 2 ≤ J ≤ 54 and 0 ≤ K ≤ 10. These data, combined with previously measured N2-broadening coefficients, were used to determine the air-broadening coefficients of the ν2 and ν5 bands. Finally, an empirical model was used to fit the broadening coefficients of the two bands. On average, the empirical expression reproduces successfully the measured broadening coefficients.
{"title":"O2- and air-broadening coefficients in the ν2 and ν5 bands of CH3Br","authors":"I. Majdi , S. Harbaoui , D. Ben Abdallah , J. Salem , Z. Boussetta , F. Kwabia Tchana , X. Landsheere , A. Voute , M. Hochlaf , H. Aroui","doi":"10.1016/j.jqsrt.2025.109723","DOIUrl":"10.1016/j.jqsrt.2025.109723","url":null,"abstract":"<div><div>In the present work, we measured the O<sub>2</sub>-broadening coefficients of the absorption lines in the ν<sub>2</sub> and ν<sub>5</sub> bands of methyl bromide at room temperature (<em>T</em> = 295 K) using a high-resolution Fourier Transform spectrometer. Eight spectra were recorded at pressures ranging from 2.0 to 6.5 Torr for the active gas and from 3 to 90 Torr for the perturber gas. The line shape parameters were obtained by fitting Voigt and Galatry profiles to the measured line shapes, allowing the determination of the O<sub>2</sub>-broadening coefficients for the branches over the 1250 – 1622 cm<sup>-1</sup> wavenumbers range. This range covers 1451 measured transitions with 2 ≤ <em>J</em> ≤ 54 and 0 ≤ <em>K</em> ≤ 10. These data, combined with previously measured N<sub>2</sub>-broadening coefficients, were used to determine the air-broadening coefficients of the ν<sub>2</sub> and ν<sub>5</sub> bands. Finally, an empirical model was used to fit the broadening coefficients of the two bands. On average, the empirical expression reproduces successfully the measured broadening coefficients.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"349 ","pages":"Article 109723"},"PeriodicalIF":1.9,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145423987","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}
Pub Date : 2025-11-01DOI: 10.1016/j.jqsrt.2025.109734
Bojan Sic , Elsa Jacquette , Denis Jouglet , Pierre Lafrique , Clemence Pierangelo , Raymond Armante , Olivier Lezeaux , Mahmoud El Hajj
Considering scattering in radiative transfer calculations often leads to extensively long computation times that can be prohibitive, especially in the operational context of satellite missions. Over time, numerous methods were developed to accelerate scattering calculations. In this paper, based and further built upon the work of O’Dell [1], we describe the implementation of the Low-Stream Interpolation acceleration technique in the 4A/OP radiative transfer model. The method’s acceleration relies on the execution of computationally expensive calculations only for representative points, which represent the regions in the gas absorption optical depth space called “bins”. For all other points the calculation is performed at a low accuracy and by subsequent interpolation. We have considered a number of method’s aspects, and introduced various modifications in order to optimise its accuracy and computation time. This includes: a) an extension of the method to Jacobians, b) modifications of bin and sub-bin divisions, c) implementation of automatic binning and its comparison to fixed bins, d) improvement of the computation of representative points, e) improvement of the definition of “significant scattering” used by the method, f) avoiding the redundancy of high-accuracy computation at large gas absorption optical depths, g) optimisations of the method computation domain size and h) evaluations of various possible accelerations of low-accuracy calculations. We applied the method on the MicroCarb O2 and CO2 bands in near-infrared and shortwave-infrared over a large variety of geophysical cases and discussed the impacts of the modifications and the overall performance. We confirmed that the Low-Stream Interpolation is a powerful technique to accelerate the scattering calculations and, in our model, it provided relative accuracies on polarised and unpolarised radiances and Jacobians lower than 0.05 % with acceleration of 10–50 times.
{"title":"Implementation of low stream interpolation technique to accelerate scattering calculations in the 4A/OP radiative transfer model","authors":"Bojan Sic , Elsa Jacquette , Denis Jouglet , Pierre Lafrique , Clemence Pierangelo , Raymond Armante , Olivier Lezeaux , Mahmoud El Hajj","doi":"10.1016/j.jqsrt.2025.109734","DOIUrl":"10.1016/j.jqsrt.2025.109734","url":null,"abstract":"<div><div>Considering scattering in radiative transfer calculations often leads to extensively long computation times that can be prohibitive, especially in the operational context of satellite missions. Over time, numerous methods were developed to accelerate scattering calculations. In this paper, based and further built upon the work of O’Dell [1], we describe the implementation of the Low-Stream Interpolation acceleration technique in the 4A/OP radiative transfer model. The method’s acceleration relies on the execution of computationally expensive calculations only for representative points, which represent the regions in the gas absorption optical depth space called “bins”. For all other points the calculation is performed at a low accuracy and by subsequent interpolation. We have considered a number of method’s aspects, and introduced various modifications in order to optimise its accuracy and computation time. This includes: a) an extension of the method to Jacobians, b) modifications of bin and sub-bin divisions, c) implementation of automatic binning and its comparison to fixed bins, d) improvement of the computation of representative points, e) improvement of the definition of “significant scattering” used by the method, f) avoiding the redundancy of high-accuracy computation at large gas absorption optical depths, g) optimisations of the method computation domain size and h) evaluations of various possible accelerations of low-accuracy calculations. We applied the method on the MicroCarb O<sub>2</sub> and CO<sub>2</sub> bands in near-infrared and shortwave-infrared over a large variety of geophysical cases and discussed the impacts of the modifications and the overall performance. We confirmed that the Low-Stream Interpolation is a powerful technique to accelerate the scattering calculations and, in our model, it provided relative accuracies on polarised and unpolarised radiances and Jacobians lower than 0.05 % with acceleration of 10–50 times.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"349 ","pages":"Article 109734"},"PeriodicalIF":1.9,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145423985","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}
Pub Date : 2025-11-01DOI: 10.1016/j.jqsrt.2025.109733
Yoshifumi Ota
In this study, we explored the spectral characteristics of radiance data collected by the Geostationary Interferometric Infrared Sounder (GIIRS) aboard the Feng-Yun-4B (FY-4B) geostationary meteorological satellite. We compared GIIRS brightness temperature observations with the first guess from the regional numerical weather forecast model of the Japan Meteorological Agency, and analyzed the bias errors in brightness temperature under clear-sky conditions. In the longwave band, we observed checkerboard patterns of bias error distributions in the CO2 channel. Focusing on the imaginary signals from the radiance data obtained through interferometry with a Fourier transform spectrometer, we believe that the observed bias errors are primarily attributed to electrical factors rather than GIIRS interferometry itself, and most of these errors can be corrected by estimating them in advance. Conversely, in the midwave band, we observed concave bias error distributions in the GIIRS instrument’s dwell, indicating that these may be related to GIIRS interferometry. Additionally, we examined the characteristics of the imaginary signal under cloudy conditions by comparing it with the cloud physical property products from Himawari-9. It was observed that large imaginary signals tended to appear in GIIRS data for scenes with high clouds and low brightness temperatures. This indicates that the imaginary signal could serve as auxiliary information for assessing whether observations are influenced by clouds, particularly high clouds including optically thin cirrus clouds. For the quantitative use of GIIRS data, it is important to consider these bias errors and perform quality control using the imaginary signal.
{"title":"Quality control for infrared radiance of geostationary meteorological satellite using imaginary signal of Fourier transform spectroscopy","authors":"Yoshifumi Ota","doi":"10.1016/j.jqsrt.2025.109733","DOIUrl":"10.1016/j.jqsrt.2025.109733","url":null,"abstract":"<div><div>In this study, we explored the spectral characteristics of radiance data collected by the Geostationary Interferometric Infrared Sounder (GIIRS) aboard the Feng-Yun-4B (FY-4B) geostationary meteorological satellite. We compared GIIRS brightness temperature observations with the first guess from the regional numerical weather forecast model of the Japan Meteorological Agency, and analyzed the bias errors in brightness temperature under clear-sky conditions. In the longwave band, we observed checkerboard patterns of bias error distributions in the CO<sub>2</sub> channel. Focusing on the imaginary signals from the radiance data obtained through interferometry with a Fourier transform spectrometer, we believe that the observed bias errors are primarily attributed to electrical factors rather than GIIRS interferometry itself, and most of these errors can be corrected by estimating them in advance. Conversely, in the midwave band, we observed concave bias error distributions in the GIIRS instrument’s dwell, indicating that these may be related to GIIRS interferometry. Additionally, we examined the characteristics of the imaginary signal under cloudy conditions by comparing it with the cloud physical property products from Himawari-9. It was observed that large imaginary signals tended to appear in GIIRS data for scenes with high clouds and low brightness temperatures. This indicates that the imaginary signal could serve as auxiliary information for assessing whether observations are influenced by clouds, particularly high clouds including optically thin cirrus clouds. For the quantitative use of GIIRS data, it is important to consider these bias errors and perform quality control using the imaginary signal.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"348 ","pages":"Article 109733"},"PeriodicalIF":1.9,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145423986","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}
Pub Date : 2025-10-31DOI: 10.1016/j.jqsrt.2025.109721
Egor O. Dobrolyubov , Ilya M. Efremov , Sergey V. Krasnoshchekov , Igor V. Polyakov , Vladimir B. Laptev , Sergey A. Klimin , Dmitry V. Millionshchikov , Olga V. Naumenko
<div><div>A ro-vibrational analysis of a high-resolution IR spectrum of an isotopic mixture of the atmospheric pollutant chlorodifluoromethane (HCFC-22), enriched in <sup>13</sup>C to 29.8 ± 0.14%, was performed in the range of 779–849 cm<sup>−1</sup>, and the identification of spectral features was limited to most abundant species <sup>12</sup>CH<sup>35</sup>ClF2 and <sup>13</sup>CH<sup>35</sup>ClF<sub>2</sub>. The spectrum was recorded on a Bruker IFS-125HR FT spectrometer at room temperature with a resolution of <span><math><mo>≈</mo></math></span>0.001 cm<sup>−1</sup>. The inverse spectroscopic problem for the main isotopologue <sup>12</sup>CH<sup>35</sup>ClF<sub>2</sub> was solved with Watson-type <span><math><mi>A</mi></math></span>-reduced effective Hamiltonian (<span><math><msub><mrow><mi>H</mi></mrow><mrow><mi>eff</mi></mrow></msub></math></span>) with accounting of the <span><math><mrow><msub><mrow><mi>ν</mi></mrow><mrow><mn>4</mn></mrow></msub><mo>/</mo><mn>2</mn><msub><mrow><mi>ν</mi></mrow><mrow><mn>6</mn></mrow></msub></mrow></math></span> Fermi resonance and the <span><math><mrow><msub><mrow><mi>ν</mi></mrow><mrow><mn>4</mn></mrow></msub><mo>/</mo><msub><mrow><mi>ν</mi></mrow><mrow><mn>6</mn></mrow></msub><mo>+</mo><msub><mrow><mi>ν</mi></mrow><mrow><mn>9</mn></mrow></msub></mrow></math></span> Coriolis resonance. The identified 3003 transitions of <span><math><msub><mrow><mi>ν</mi></mrow><mrow><mn>4</mn></mrow></msub></math></span> and 1265 transitions of <span><math><mrow><mn>2</mn><msub><mrow><mi>ν</mi></mrow><mrow><mn>6</mn></mrow></msub></mrow></math></span> produced 1598 empirical upper energy levels of the <span><math><msub><mrow><mi>ν</mi></mrow><mrow><mn>4</mn></mrow></msub></math></span> (<span><math><mrow><mi>J</mi><mo>≤</mo><mn>81</mn><mo>,</mo><msub><mrow><mi>K</mi></mrow><mrow><mi>a</mi></mrow></msub><mo>≤</mo><mn>13</mn></mrow></math></span>) and 840 levels of the <span><math><mrow><mn>2</mn><msub><mrow><mi>ν</mi></mrow><mrow><mn>6</mn></mrow></msub></mrow></math></span> band (<span><math><mrow><mi>J</mi><mo>≤</mo><mn>71</mn><mo>,</mo><msub><mrow><mi>K</mi></mrow><mrow><mi>a</mi></mrow></msub><mo>≤</mo><mn>11</mn></mrow></math></span>) with RMSD = 2.92<span><math><mrow><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>4</mn></mrow></msup></mrow></math></span> cm<sup>−1</sup>. For the <sup>13</sup>CH<sup>35</sup>ClF<sub>2</sub> isotopologue, 670 transitions and corresponding empirical 350 energy levels of <span><math><msub><mrow><mi>ν</mi></mrow><mrow><mn>4</mn></mrow></msub></math></span> band (<span><math><mrow><mi>J</mi><mo>≤</mo><mn>34</mn><mo>,</mo><msub><mrow><mi>K</mi></mrow><mrow><mi>a</mi></mrow></msub><mo>≤</mo><mn>10</mn></mrow></math></span>) were identified for the first time. The effective model consisted of a <span><math><mrow><msub><mrow><mi>ν</mi></mrow><mrow><mn>4</mn></mrow></msub><mo>/</mo><msub><mrow><mi>ν</mi></mrow><mrow><mn>6</mn></mrow></msub><mo>+</mo><msub><mrow><mi>ν</mi>
{"title":"High-resolution ro-vibrational analysis of HCFC-22: Deciphering ν4 and 2ν6 bands of 12CH35ClF2 and ν4 band of 13CH35ClF2 species","authors":"Egor O. Dobrolyubov , Ilya M. Efremov , Sergey V. Krasnoshchekov , Igor V. Polyakov , Vladimir B. Laptev , Sergey A. Klimin , Dmitry V. Millionshchikov , Olga V. Naumenko","doi":"10.1016/j.jqsrt.2025.109721","DOIUrl":"10.1016/j.jqsrt.2025.109721","url":null,"abstract":"<div><div>A ro-vibrational analysis of a high-resolution IR spectrum of an isotopic mixture of the atmospheric pollutant chlorodifluoromethane (HCFC-22), enriched in <sup>13</sup>C to 29.8 ± 0.14%, was performed in the range of 779–849 cm<sup>−1</sup>, and the identification of spectral features was limited to most abundant species <sup>12</sup>CH<sup>35</sup>ClF2 and <sup>13</sup>CH<sup>35</sup>ClF<sub>2</sub>. The spectrum was recorded on a Bruker IFS-125HR FT spectrometer at room temperature with a resolution of <span><math><mo>≈</mo></math></span>0.001 cm<sup>−1</sup>. The inverse spectroscopic problem for the main isotopologue <sup>12</sup>CH<sup>35</sup>ClF<sub>2</sub> was solved with Watson-type <span><math><mi>A</mi></math></span>-reduced effective Hamiltonian (<span><math><msub><mrow><mi>H</mi></mrow><mrow><mi>eff</mi></mrow></msub></math></span>) with accounting of the <span><math><mrow><msub><mrow><mi>ν</mi></mrow><mrow><mn>4</mn></mrow></msub><mo>/</mo><mn>2</mn><msub><mrow><mi>ν</mi></mrow><mrow><mn>6</mn></mrow></msub></mrow></math></span> Fermi resonance and the <span><math><mrow><msub><mrow><mi>ν</mi></mrow><mrow><mn>4</mn></mrow></msub><mo>/</mo><msub><mrow><mi>ν</mi></mrow><mrow><mn>6</mn></mrow></msub><mo>+</mo><msub><mrow><mi>ν</mi></mrow><mrow><mn>9</mn></mrow></msub></mrow></math></span> Coriolis resonance. The identified 3003 transitions of <span><math><msub><mrow><mi>ν</mi></mrow><mrow><mn>4</mn></mrow></msub></math></span> and 1265 transitions of <span><math><mrow><mn>2</mn><msub><mrow><mi>ν</mi></mrow><mrow><mn>6</mn></mrow></msub></mrow></math></span> produced 1598 empirical upper energy levels of the <span><math><msub><mrow><mi>ν</mi></mrow><mrow><mn>4</mn></mrow></msub></math></span> (<span><math><mrow><mi>J</mi><mo>≤</mo><mn>81</mn><mo>,</mo><msub><mrow><mi>K</mi></mrow><mrow><mi>a</mi></mrow></msub><mo>≤</mo><mn>13</mn></mrow></math></span>) and 840 levels of the <span><math><mrow><mn>2</mn><msub><mrow><mi>ν</mi></mrow><mrow><mn>6</mn></mrow></msub></mrow></math></span> band (<span><math><mrow><mi>J</mi><mo>≤</mo><mn>71</mn><mo>,</mo><msub><mrow><mi>K</mi></mrow><mrow><mi>a</mi></mrow></msub><mo>≤</mo><mn>11</mn></mrow></math></span>) with RMSD = 2.92<span><math><mrow><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>4</mn></mrow></msup></mrow></math></span> cm<sup>−1</sup>. For the <sup>13</sup>CH<sup>35</sup>ClF<sub>2</sub> isotopologue, 670 transitions and corresponding empirical 350 energy levels of <span><math><msub><mrow><mi>ν</mi></mrow><mrow><mn>4</mn></mrow></msub></math></span> band (<span><math><mrow><mi>J</mi><mo>≤</mo><mn>34</mn><mo>,</mo><msub><mrow><mi>K</mi></mrow><mrow><mi>a</mi></mrow></msub><mo>≤</mo><mn>10</mn></mrow></math></span>) were identified for the first time. The effective model consisted of a <span><math><mrow><msub><mrow><mi>ν</mi></mrow><mrow><mn>4</mn></mrow></msub><mo>/</mo><msub><mrow><mi>ν</mi></mrow><mrow><mn>6</mn></mrow></msub><mo>+</mo><msub><mrow><mi>ν</mi>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"348 ","pages":"Article 109721"},"PeriodicalIF":1.9,"publicationDate":"2025-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145412040","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}
Pub Date : 2025-10-31DOI: 10.1016/j.jqsrt.2025.109731
Yun-Fei Li , Jun-Yao Zhang , Jing-Yi Xiong , Kai-Chen Ma , Li-De Wang , Cai-Hua Zhu
The ultraviolet spectrum of Gd I in the 305–325 nm range was studied using resonance ionization spectroscopy, revealing 196 transition lines, including 66 strong ones. The lower and upper energy levels were assigned to 190 lines by combining available reference data with pump–probe verification, 172 of which are reported for the first time. Seventeen new even-parity high-lying excited states were also identified. The strong lines reported here will contribute to future studies of Gd I Rydberg and autoionization states and enable two-color, two-step photoionization pathways for isotope separation and resonance ionization mass spectrometry analysis.
利用共振电离光谱研究了Gd I在305 ~ 325 nm范围内的紫外光谱，共发现196条过渡谱线，其中强过渡谱线66条。结合现有参考数据和泵-探针验证，对190条管线进行了上下能级划分，其中172条管线为首次报告。还发现了17个新的偶宇称高位激发态。本文报道的强谱线将有助于未来Gd I Rydberg和自电离态的研究，并为同位素分离和共振电离质谱分析提供双色、两步光电离途径。
{"title":"Investigation of ultraviolet spectrum and energy level assignments of Gd I in the 305–325nm region","authors":"Yun-Fei Li , Jun-Yao Zhang , Jing-Yi Xiong , Kai-Chen Ma , Li-De Wang , Cai-Hua Zhu","doi":"10.1016/j.jqsrt.2025.109731","DOIUrl":"10.1016/j.jqsrt.2025.109731","url":null,"abstract":"<div><div>The ultraviolet spectrum of Gd I in the 305–325 nm range was studied using resonance ionization spectroscopy, revealing 196 transition lines, including 66 strong ones. The lower and upper energy levels were assigned to 190 lines by combining available reference data with pump–probe verification, 172 of which are reported for the first time. Seventeen new even-parity high-lying excited states were also identified. The strong lines reported here will contribute to future studies of Gd I Rydberg and autoionization states and enable two-color, two-step photoionization pathways for isotope separation and resonance ionization mass spectrometry analysis.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"348 ","pages":"Article 109731"},"PeriodicalIF":1.9,"publicationDate":"2025-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145412039","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}
Pub Date : 2025-10-30DOI: 10.1016/j.jqsrt.2025.109713
S. Korkin , A.M. Sayer , A. Ibrahim , A. Lyapustin
{"title":"Corrigendum to “A practical guide to coding line-by-line trace gas absorption in Earth's atmosphere” [Journal of Quantitative Spectroscopy & Radiative Transfer 337 (2025) 109345]","authors":"S. Korkin , A.M. Sayer , A. Ibrahim , A. Lyapustin","doi":"10.1016/j.jqsrt.2025.109713","DOIUrl":"10.1016/j.jqsrt.2025.109713","url":null,"abstract":"","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"348 ","pages":"Article 109713"},"PeriodicalIF":1.9,"publicationDate":"2025-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145405045","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}
Pub Date : 2025-10-28DOI: 10.1016/j.jqsrt.2025.109716
Julieta Olivo , Hernán Ferrari , Jorge L. Blengino Albrieu , Mauro Cuevas
This work focuses on the study of the electromagnetic density spectral function (DSF) near a graphene–dielectric cavity. The cavity is formed in the space confined by the base of a dielectric micro-cube and a planar graphene sheet covering a dielectric substrate. The size and refractive index of the micro-cube, the constitutive parameters of graphene, and the gap between the dielectric cube and the graphene sheet determine the modifications to the DSF. We have developed a method based on the coupled dipole approximation (CDA), incorporating the surface Green’s tensor to account for the scattering processes with the graphene substrate, thereby rigorously modeling the electromagnetic problem. Our results reveal three well-distinguishable peaks in the DSF spectrum, which are attributed to the isolated micro-cube, the graphene substrate, and their mutual interaction. Specific parameters allow for the selective tuning of an individual peak’s properties, with minimal crosstalk to other spectral features. Using simple physical arguments related to the kinetic characteristics of surface plasmons (SPs) on graphene, we explain the key dependencies on constitutive and geometrical parameters.
{"title":"Tuning the electromagnetic density spectral function in a graphene–dielectric micro-cavity","authors":"Julieta Olivo , Hernán Ferrari , Jorge L. Blengino Albrieu , Mauro Cuevas","doi":"10.1016/j.jqsrt.2025.109716","DOIUrl":"10.1016/j.jqsrt.2025.109716","url":null,"abstract":"<div><div>This work focuses on the study of the electromagnetic density spectral function (DSF) near a graphene–dielectric cavity. The cavity is formed in the space confined by the base of a dielectric micro-cube and a planar graphene sheet covering a dielectric substrate. The size and refractive index of the micro-cube, the constitutive parameters of graphene, and the gap between the dielectric cube and the graphene sheet determine the modifications to the DSF. We have developed a method based on the coupled dipole approximation (CDA), incorporating the surface Green’s tensor to account for the scattering processes with the graphene substrate, thereby rigorously modeling the electromagnetic problem. Our results reveal three well-distinguishable peaks in the DSF spectrum, which are attributed to the isolated micro-cube, the graphene substrate, and their mutual interaction. Specific parameters allow for the selective tuning of an individual peak’s properties, with minimal crosstalk to other spectral features. Using simple physical arguments related to the kinetic characteristics of surface plasmons (SPs) on graphene, we explain the key dependencies on constitutive and geometrical parameters.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"348 ","pages":"Article 109716"},"PeriodicalIF":1.9,"publicationDate":"2025-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145383142","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}
Pub Date : 2025-10-27DOI: 10.1016/j.jqsrt.2025.109707
Indranath Mukhopadhyay
In this work, the high-resolution far infrared (FIR) and infrared (IR) spectrum of ethyl alcohol has been recorded in the range 50–1200 cm-1, with an excellent signal-to-noise (S/N) ratio, using a synchrotron radiation-based Fourier transform spectrometer. This spectrum, along with the spectrum obtained earlier with a conventional Fourier transform spectrometer in the range 15–350 cm-1, has been utilized to assign many ∆K=±1 transitions from the trans- or anti and gauche-states in the ground state to connect the lowest lying state (o2) for the first excited OH torsional vibrational band. Since the transitions originating from the trans- states are the strongest mode, the terminating state is termed trans (anti) State (o2). However, this state has odd parity. In addition, many millimeter (MMW) wave transitions have been measured elsewhere and assigned. The assignments have been rigorously confirmed using several complementary methods. An expanded appendix (Appendix-1) of about 8000 accurate wavenumbers of assigned transitions in the millimeter (MMW), FIR, and IR regions has been prepared and is being submitted as a depository. The assignments allowed indirect energy differences between the trans- and gauche states in the ground state, which are not otherwise obtainable via dipole selection rules. The accurate wavenumbers should help detect ethanol in interstellar space, particularly using the IR telescopes, and for further studies on intricate interactions between the various vibrational modes and rotation. This is the first time high-resolution studies have been performed in the elusive excited torsional state of ethyl alcohol. The reported transition wavenumber should have an uncertainty of less than ±0.0002 cm-1
{"title":"First high-resolution spectral study of the far infrared fundamental OH- torsional band of ethyl alcohol (CH3CH2OH), using synchrotron radiation","authors":"Indranath Mukhopadhyay","doi":"10.1016/j.jqsrt.2025.109707","DOIUrl":"10.1016/j.jqsrt.2025.109707","url":null,"abstract":"<div><div>In this work, the high-resolution far infrared (FIR) and infrared (IR) spectrum of ethyl alcohol has been recorded in the range 50–1200 cm<sup>-1</sup>, with an excellent signal-to-noise (S/N) ratio, using a synchrotron radiation-based Fourier transform spectrometer. This spectrum, along with the spectrum obtained earlier with a conventional Fourier transform spectrometer in the range 15–350 cm<sup>-1</sup>, has been utilized to assign many ∆<em>K</em>=±1 transitions from the trans- or anti and gauche-states in the ground state to connect the lowest lying state (o<sub>2</sub>) for the first excited O<img>H torsional vibrational band. Since the transitions originating from the trans- states are the strongest mode, the terminating state is termed trans (anti) State (o<sub>2</sub>). However, this state has odd parity. In addition, many millimeter (MMW) wave transitions have been measured elsewhere and assigned. The assignments have been rigorously confirmed using several complementary methods. An expanded appendix (Appendix-1) of about 8000 accurate wavenumbers of assigned transitions in the millimeter (MMW), FIR, and IR regions has been prepared and is being submitted as a depository. The assignments allowed indirect energy differences between the trans- and gauche states in the ground state, which are not otherwise obtainable via dipole selection rules. The accurate wavenumbers should help detect ethanol in interstellar space, particularly using the IR telescopes, and for further studies on intricate interactions between the various vibrational modes and rotation. This is the first time high-resolution studies have been performed in the elusive excited torsional state of ethyl alcohol. The reported transition wavenumber should have an uncertainty of less than ±0.0002 cm<sup>-1</sup></div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"349 ","pages":"Article 109707"},"PeriodicalIF":1.9,"publicationDate":"2025-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145383148","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}
Pub Date : 2025-10-27DOI: 10.1016/j.jqsrt.2025.109719
S. Eser , G. Günday Konan , B. Karaçoban Usta , İ. Gülsoy
In this study, level energies, their radiative lifetimes and Landé g-factors, wavelengths, transition probabilities, weighted oscillator strengths and line strengths for electric dipole (E1) and electric quadrupole (E2) transitions of sodium-like zirconium (Zr(Zr XXX), Z = 40) are determined. Four atomic codes are used in the calculations: the pseudo-relativistic Hartree–Fock code, including superposition of configurations with relativistic corrections (Cowan’s HFR method), the multiconfiguration Hartree–Fock (MCHF) method within the framework of Breit–Pauli relativistic corrections, the AUTOSTRUCTURE code, which includes Breit interactions and quantum electrodynamics contributions, and the general-purpose relativistic atomic structure package (GRASP) based on a fully relativistic multiconfiguration Dirac–Fock (MCDF) method. Our data set is compared with other results available in the literature. Furthermore, we present new atomic data for Zr, which have not been published previously. The present results are reported as reference points for future calculations and measurements.
本研究确定了类钠锆（Zr+29(Zr XXX), Z = 40）电偶极子（E1）和电四极子（E2）跃迁的能级能、辐射寿命和land g因子、波长、跃迁概率、加权振子强度和线强度。计算中使用了四种原子代码：伪相对论Hartree-Fock代码，包括带相对论修正的组态叠加（Cowan的HFR方法），Breit - pauli相对论修正框架内的多组态Hartree-Fock （MCHF）方法，AUTOSTRUCTURE代码，包括Breit相互作用和量子电动力学贡献，以及基于完全相对论多组态Dirac-Fock （MCDF）方法的通用相对论原子结构包（GRASP）。我们的数据集与文献中其他可用的结果进行了比较。此外，我们提出了Zr+29的新原子数据，这是以前没有发表过的。本报告的结果作为今后计算和测量的参考点。
{"title":"Theoretical studies of allowed (E1) and forbidden (E2) transitions in Zr+29","authors":"S. Eser , G. Günday Konan , B. Karaçoban Usta , İ. Gülsoy","doi":"10.1016/j.jqsrt.2025.109719","DOIUrl":"10.1016/j.jqsrt.2025.109719","url":null,"abstract":"<div><div>In this study, level energies, their radiative lifetimes and Landé <em>g</em>-factors, wavelengths, transition probabilities, weighted oscillator strengths and line strengths for electric dipole (E1) and electric quadrupole (E2) transitions of sodium-like zirconium (Zr<span><math><msup><mrow></mrow><mrow><mo>+</mo><mn>29</mn></mrow></msup></math></span>(Zr XXX), Z = 40) are determined. Four atomic codes are used in the calculations: the pseudo-relativistic Hartree–Fock code, including superposition of configurations with relativistic corrections (Cowan’s HFR method), the multiconfiguration Hartree–Fock (MCHF) method within the framework of Breit–Pauli relativistic corrections, the AUTOSTRUCTURE code, which includes Breit interactions and quantum electrodynamics contributions, and the general-purpose relativistic atomic structure package (GRASP) based on a fully relativistic multiconfiguration Dirac–Fock (MCDF) method. Our data set is compared with other results available in the literature. Furthermore, we present new atomic data for Zr<span><math><msup><mrow></mrow><mrow><mo>+</mo><mn>29</mn></mrow></msup></math></span>, which have not been published previously. The present results are reported as reference points for future calculations and measurements.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"348 ","pages":"Article 109719"},"PeriodicalIF":1.9,"publicationDate":"2025-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145383147","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}
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