Pub Date : 2024-09-30DOI: 10.1016/j.jqsrt.2024.109205
O.N. Ulenikov , O.V. Gromova , E.S. Bekhtereva , Yu.S. Aslapovskaya , Yu.V. Sypchenko , C. Sydow , C. Maul , S. Bauerecker
<div><div>A highly accurate rotational–vibrational analysis of Fourier transform infrared spectra of the <span><math><msup><mrow></mrow><mrow><mn>12</mn></mrow></msup></math></span>CD<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span> molecule is presented. The high resolution infrared spectra were measured with a IFS125 HR Fourier transform interferometer from Bruker at an optical resolution of 0.003 cm<sup>−1</sup> and analyzed in the 1750–2400 cm<sup>−1</sup> region. Here the <span><math><mrow><mn>2</mn><msub><mrow><mi>ν</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></math></span>, <span><math><mrow><msub><mrow><mi>ν</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>+</mo><msub><mrow><mi>ν</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math></span>, <span><math><mrow><mn>2</mn><msub><mrow><mi>ν</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math></span>, <span><math><msub><mrow><mi>ν</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span> and <span><math><msub><mrow><mi>ν</mi></mrow><mrow><mn>3</mn></mrow></msub></math></span> bands (altogether, nine sub-bands of different symmetry) of the pentad are located. The number of 1213/1993/1576/77/1582 transitions with the <span><math><msup><mrow><mi>J</mi></mrow><mrow><mtext>max</mtext></mrow></msup></math></span> = 23/23/23/14/32 were assigned to the <span><math><mrow><mn>2</mn><msub><mrow><mi>ν</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></math></span>, <span><math><mrow><msub><mrow><mi>ν</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>+</mo><msub><mrow><mi>ν</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math></span>, <span><math><mrow><mn>2</mn><msub><mrow><mi>ν</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math></span>, <span><math><msub><mrow><mi>ν</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span> and <span><math><msub><mrow><mi>ν</mi></mrow><mrow><mn>3</mn></mrow></msub></math></span> bands of <span><math><msup><mrow></mrow><mrow><mn>12</mn></mrow></msup></math></span>CD<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>. The obtained experimental data were used for the determination of the upper ro-vibrational energy values. To provide more correct values of the upper energies, more than 7800 highly accurate “hot” transitions from the dyad region were additionally processed. In general, 4088 upper ro-vibrational energies of the pentad (for comparison, 2525 upper ro-vibrational energies with the value of <span><math><mrow><msup><mrow><mi>J</mi></mrow><mrow><mtext>max</mtext></mrow></msup><mo>=</mo><mn>20</mn></mrow></math></span> are known in the modern literature up to now) were determined, which were used then in the weighted fit procedure with a goal to determine the spectroscopic parameters (band centers, rotational, centrifugal distortion, tetrahedral splitting and resonance interaction parameters) of the effective Hamiltonian. The obtained <span><math><msub><mrow><mi>d</mi></mrow><mrow><mtext>rms</mtext></mrow></msub></mat
{"title":"High resolution analysis of the CD4 deuterated methane: Extended investigation of the pentad region","authors":"O.N. Ulenikov , O.V. Gromova , E.S. Bekhtereva , Yu.S. Aslapovskaya , Yu.V. Sypchenko , C. Sydow , C. Maul , S. Bauerecker","doi":"10.1016/j.jqsrt.2024.109205","DOIUrl":"10.1016/j.jqsrt.2024.109205","url":null,"abstract":"<div><div>A highly accurate rotational–vibrational analysis of Fourier transform infrared spectra of the <span><math><msup><mrow></mrow><mrow><mn>12</mn></mrow></msup></math></span>CD<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span> molecule is presented. The high resolution infrared spectra were measured with a IFS125 HR Fourier transform interferometer from Bruker at an optical resolution of 0.003 cm<sup>−1</sup> and analyzed in the 1750–2400 cm<sup>−1</sup> region. Here the <span><math><mrow><mn>2</mn><msub><mrow><mi>ν</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></math></span>, <span><math><mrow><msub><mrow><mi>ν</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>+</mo><msub><mrow><mi>ν</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math></span>, <span><math><mrow><mn>2</mn><msub><mrow><mi>ν</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math></span>, <span><math><msub><mrow><mi>ν</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span> and <span><math><msub><mrow><mi>ν</mi></mrow><mrow><mn>3</mn></mrow></msub></math></span> bands (altogether, nine sub-bands of different symmetry) of the pentad are located. The number of 1213/1993/1576/77/1582 transitions with the <span><math><msup><mrow><mi>J</mi></mrow><mrow><mtext>max</mtext></mrow></msup></math></span> = 23/23/23/14/32 were assigned to the <span><math><mrow><mn>2</mn><msub><mrow><mi>ν</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></math></span>, <span><math><mrow><msub><mrow><mi>ν</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>+</mo><msub><mrow><mi>ν</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math></span>, <span><math><mrow><mn>2</mn><msub><mrow><mi>ν</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math></span>, <span><math><msub><mrow><mi>ν</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span> and <span><math><msub><mrow><mi>ν</mi></mrow><mrow><mn>3</mn></mrow></msub></math></span> bands of <span><math><msup><mrow></mrow><mrow><mn>12</mn></mrow></msup></math></span>CD<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>. The obtained experimental data were used for the determination of the upper ro-vibrational energy values. To provide more correct values of the upper energies, more than 7800 highly accurate “hot” transitions from the dyad region were additionally processed. In general, 4088 upper ro-vibrational energies of the pentad (for comparison, 2525 upper ro-vibrational energies with the value of <span><math><mrow><msup><mrow><mi>J</mi></mrow><mrow><mtext>max</mtext></mrow></msup><mo>=</mo><mn>20</mn></mrow></math></span> are known in the modern literature up to now) were determined, which were used then in the weighted fit procedure with a goal to determine the spectroscopic parameters (band centers, rotational, centrifugal distortion, tetrahedral splitting and resonance interaction parameters) of the effective Hamiltonian. The obtained <span><math><msub><mrow><mi>d</mi></mrow><mrow><mtext>rms</mtext></mrow></msub></mat","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"329 ","pages":"Article 109205"},"PeriodicalIF":2.3,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142423786","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 : 2024-09-29DOI: 10.1016/j.jqsrt.2024.109204
Prakash Gautam , Hans Moosmüller , Justin B. Maughan , Christopher M. Sorensen
The purpose of this paper is to study the dependency of light backscattering on particle physical properties: size, refractive index, and shape; and to demonstrate the extreme sensitivity of backscattering on these properties. We demonstrate how the nondescript backscattering pattern evolves seemingly chaotic, in contrast to the orderly forward scattering, with the particle's physical properties. The demonstration was carried out by light scattering from water droplets and with spherical particle Mie theory. Our results show systematic, descriptive evolution of the forward scattering pattern, which is clearly shown in logarithmic Q–space, whereas non-descriptive, chaotic evolution within the backscattering regime is displayed in linear θ–space. Additionally, our study shows that within the last 1°, the backscattering intensity remains constant and featureless for the ∼ 2.5 μm diameter water droplets investigated here.
{"title":"Sensitivity of backscattering to spherical particle physical properties: Size, refractive index, and shape deviations","authors":"Prakash Gautam , Hans Moosmüller , Justin B. Maughan , Christopher M. Sorensen","doi":"10.1016/j.jqsrt.2024.109204","DOIUrl":"10.1016/j.jqsrt.2024.109204","url":null,"abstract":"<div><div>The purpose of this paper is to study the dependency of light backscattering on particle physical properties: size, refractive index, and shape; and to demonstrate the extreme sensitivity of backscattering on these properties. We demonstrate how the nondescript backscattering pattern evolves seemingly chaotic, in contrast to the orderly forward scattering, with the particle's physical properties. The demonstration was carried out by light scattering from water droplets and with spherical particle Mie theory. Our results show systematic, descriptive evolution of the forward scattering pattern, which is clearly shown in logarithmic Q–space, whereas non-descriptive, chaotic evolution within the backscattering regime is displayed in linear θ–space. Additionally, our study shows that within the last 1°, the backscattering intensity remains constant and featureless for the ∼ 2.5 μm diameter water droplets investigated here.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"329 ","pages":"Article 109204"},"PeriodicalIF":2.3,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142423840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Pub Date : 2024-09-29DOI: 10.1016/j.jqsrt.2024.109209
Ahmed El-Habashi , Samir Ahmed
The impact of the un-polarized nature of chlorophyll fluorescence, which causes a dip in the degree of polarization of the underwater light field matching the fluorescence spectrum, led to the development of a theoretical relationship indicating that the resulting fractional reduction in observed polarization is linearly proportional to the magnitude of the fluorescence causing it. To evaluate this relationship, we used a vector radiative transfer code (VRTE) for the coupled atmosphere-ocean system using measured inherent optical properties (IOPs) for a variety of oligotrophic and eutrophic waters as inputs. The VRTE was used to simulate elastic components of the underwater reflectance as well as the degree of linear polarization (DoLP) for these different conditions. These values were compared with the underwater reflectances and the DoLPs measured by a multi-angular hyperspectral polarimeter to determine the magnitude of the fluorescence component in the reflectance spectra at 685 nm, and the decrease of the DoLP due to the fluorescence impact at the same wavelength. Fluorescence magnitudes retrieved from the differences between simulated and measured reflectances were found to match well the magnitudes estimated through the relationship based on the drop of the DoLP. It is noted that retrieval accuracies increase for both larger fluorescence and larger underlying DoLP values. Furthermore, a new method is evolved from the measured polarization analysis, Polarization-Curve Fluorescence Height (PCFH). Measured polarization were used to approximate the elastic signal and derive the inelastic un-polarized signal (fluorescence) from the difference in the fluorescence vicinity. These results open possibilities for estimating the magnitude of natural fluorescence using polarization measurements below or above the water surface, .in-situ, or remotely from aircraft or future satellites. Results of ongoing work on potential sensitivities and retrieval accuracies for these applications will be reported.
{"title":"The relationship between chlorophyll fluorescence and polarized light field: Polarization-curve fluorescence height","authors":"Ahmed El-Habashi , Samir Ahmed","doi":"10.1016/j.jqsrt.2024.109209","DOIUrl":"10.1016/j.jqsrt.2024.109209","url":null,"abstract":"<div><div>The impact of the un-polarized nature of chlorophyll fluorescence, which causes a dip in the degree of polarization of the underwater light field matching the fluorescence spectrum, led to the development of a theoretical relationship indicating that the resulting fractional reduction in observed polarization is linearly proportional to the magnitude of the fluorescence causing it. To evaluate this relationship, we used a vector radiative transfer code (VRTE) for the coupled atmosphere-ocean system using measured inherent optical properties (IOPs) for a variety of oligotrophic and eutrophic waters as inputs. The VRTE was used to simulate elastic components of the underwater reflectance as well as the degree of linear polarization (DoLP) for these different conditions. These values were compared with the underwater reflectances and the DoLPs measured by a multi-angular hyperspectral polarimeter to determine the magnitude of the fluorescence component in the reflectance spectra at 685 nm, and the decrease of the DoLP due to the fluorescence impact at the same wavelength. Fluorescence magnitudes retrieved from the differences between simulated and measured reflectances were found to match well the magnitudes estimated through the relationship based on the drop of the DoLP. It is noted that retrieval accuracies increase for both larger fluorescence and larger underlying DoLP values. Furthermore, a new method is evolved from the measured polarization analysis, Polarization-Curve Fluorescence Height (PCFH). Measured polarization were used to approximate the elastic signal and derive the inelastic un-polarized signal (fluorescence) from the difference in the fluorescence vicinity. These results open possibilities for estimating the magnitude of natural fluorescence using polarization measurements below or above the water surface, <em>.in-situ</em>, or remotely from aircraft or future satellites. Results of ongoing work on potential sensitivities and retrieval accuracies for these applications will be reported.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"329 ","pages":"Article 109209"},"PeriodicalIF":2.3,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142423839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
The cavity ring-down spectra (CRDS) of nitrous oxide were recorded at a pressure of 10 hPa in the 11,937–12,223 cm-1 range with a threshold sensitivity to absorption coefficient of the order of 6.5 × 10–11 cm-1. Three bands (ν1+5ν3, 6ν1+2ν3, and 3ν1+4ν3) were detected. The line centers and intensities were recovered from the observed spectra. The spectroscopic constants of the upper vibrational states and the vibrational transition dipole moment parameters were fitted to the measured line positions and intensities, respectively. It was found that the 3ν1+4ν3 band is in the interpolyad Coriolis resonance interaction with the band. This interaction leads to the appearance in the spectra of the four extra lines of the band.
{"title":"Cavity ring-down spectroscopy of 14N216O near 0.83 µm","authors":"L.N. Sinitsa, S.S. Vasilchenko, N.M. Emelyanov, A.A. Marinina, V.I. Perevalov","doi":"10.1016/j.jqsrt.2024.109210","DOIUrl":"10.1016/j.jqsrt.2024.109210","url":null,"abstract":"<div><div>The cavity ring-down spectra (CRDS) of nitrous oxide were recorded at a pressure of 10 hPa in the 11,937–12,223 cm<sup>-1</sup> range with a threshold sensitivity to absorption coefficient of the order of 6.5 × 10<sup>–11</sup> cm<sup>-1</sup>. Three bands (<em>ν</em><sub>1</sub>+5<em>ν</em><sub>3</sub>, 6<em>ν</em><sub>1</sub>+2<em>ν</em><sub>3</sub>, and 3<em>ν</em><sub>1</sub>+4<em>ν</em><sub>3</sub>) were detected. The line centers and intensities were recovered from the observed spectra. The spectroscopic constants of the upper vibrational states and the vibrational transition dipole moment parameters were fitted to the measured line positions and intensities, respectively. It was found that the 3<em>ν</em><sub>1</sub>+4<em>ν</em><sub>3</sub> band is in the interpolyad Coriolis resonance interaction with the <span><math><mrow><mn>7</mn><msub><mi>ν</mi><mn>1</mn></msub><mo>+</mo><mn>7</mn><msubsup><mi>ν</mi><mn>2</mn><mn>1</mn></msubsup></mrow></math></span> band. This interaction leads to the appearance in the spectra of the four extra lines of the <span><math><mrow><mn>7</mn><msub><mi>ν</mi><mn>1</mn></msub><mo>+</mo><mn>7</mn><msubsup><mi>ν</mi><mn>2</mn><mn>1</mn></msubsup></mrow></math></span> band.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"329 ","pages":"Article 109210"},"PeriodicalIF":2.3,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142423849","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 : 2024-09-27DOI: 10.1016/j.jqsrt.2024.109207
Rui Li , Xinyu Gu , Xiaohe Lin , Yong Wu
The electronic structures of silicon monobromide (SiBr) correlating with the lowest three dissociation channels are studied using high-level configuration interaction method. The spin-orbit coupling (SOC) effect and core-valence (CV) correlations effect are taken into account to improve the accuracy of electronic structures. Based on the calculated electronic structures of the lowest three dissociation channels of SiBr, the spectroscopic constants of quasibound and bound electronic states are fitted, which are coincided with the results of experiment. The dipole moment curves (DMs) of the lowest three dissociation channels of SiBr are obtained, and the abrupt change of DMs nearby the avoided crossing point are explained by the variation of electronic configurations of the corresponding states. With the help of the calculated SOC matrix elements, the predissociation channels of the low-lying vibrational states of 2Δ(Ⅱ) and 2Π(Ⅲ) sates are analyzed. The complicated interaction between crossing states is investigated. The ν'≥0 vibrational states of 2Δ(Ⅱ) and ν′≥2 vibrational states of 2Π(Ⅲ) would predissociate rapidly through predissociation channels of 2Δ(Ⅱ)-2Π(Ⅱ) and 2Π(Ⅲ)-2Σ+(Ⅱ). Finally, the transition properties of A2Σ+-X2Π, 2∆(Ⅱ)-X2Π, 2Σ+(Ⅱ)-X2Π, 2Π(Ⅲ)-X2Π, 1/2(Ⅱ)-X2Π1/2, 1/2(Ⅲ)-X2Π1/2 and 3/2(Ⅱ)-X2Π1/2 transitions are investigated, and radiative lifetime of bound states are evaluated.
{"title":"MRCI+Q calculations on electronic structure and spectroscopy of low-lying electronic states of silicon monobromide including spin-orbit coupling effect","authors":"Rui Li , Xinyu Gu , Xiaohe Lin , Yong Wu","doi":"10.1016/j.jqsrt.2024.109207","DOIUrl":"10.1016/j.jqsrt.2024.109207","url":null,"abstract":"<div><div>The electronic structures of silicon monobromide (SiBr) correlating with the lowest three dissociation channels are studied using high-level configuration interaction method. The spin-orbit coupling (SOC) effect and core-valence (CV) correlations effect are taken into account to improve the accuracy of electronic structures. Based on the calculated electronic structures of the lowest three dissociation channels of SiBr, the spectroscopic constants of quasibound and bound electronic states are fitted, which are coincided with the results of experiment. The dipole moment curves (DMs) of the lowest three dissociation channels of SiBr are obtained, and the abrupt change of DMs nearby the avoided crossing point are explained by the variation of electronic configurations of the corresponding states. With the help of the calculated SOC matrix elements, the predissociation channels of the low-lying vibrational states of <sup>2</sup>Δ(Ⅱ) and <sup>2</sup>Π(Ⅲ) sates are analyzed. The complicated interaction between crossing states is investigated. The <em>ν'</em>≥0 vibrational states of <sup>2</sup>Δ(Ⅱ) and <em>ν′</em>≥2 vibrational states of <sup>2</sup>Π(Ⅲ) would predissociate rapidly through predissociation channels of <sup>2</sup>Δ(Ⅱ)-<sup>2</sup>Π(Ⅱ) and <sup>2</sup>Π(Ⅲ)-<sup>2</sup>Σ<sup>+</sup>(Ⅱ). Finally, the transition properties of A<sup>2</sup>Σ<sup>+</sup>-X<sup>2</sup>Π, <sup>2</sup>∆(Ⅱ)-X<sup>2</sup>Π, <sup>2</sup>Σ<sup>+</sup>(Ⅱ)-X<sup>2</sup>Π, <sup>2</sup>Π(Ⅲ)-X<sup>2</sup>Π, 1/2(Ⅱ)-X<sup>2</sup>Π<sub>1/2,</sub> 1/2(Ⅲ)-X<sup>2</sup>Π<sub>1/2</sub> and 3/2(Ⅱ)-X<sup>2</sup>Π<sub>1/2</sub> transitions are investigated, and radiative lifetime of bound states are evaluated.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"329 ","pages":"Article 109207"},"PeriodicalIF":2.3,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142423825","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 : 2024-09-26DOI: 10.1016/j.jqsrt.2024.109206
Yuehua Chang , Qi Yu
Through combining experimental branching fractions (BFs) with radiative lifetimes, transition probabilities and oscillator strengths of Eu I for 39 lines from 16 excited levels were derived for the first time. The energies range from 27852.90 to 41443.70 cm-1. The BFs were determined in this work using the Fourier transform spectra available from National Solar Observatory database, and the lifetimes were obtained from literature. Furthermore, BFs for 22 lines, previously reported in the literature, were also determined for comparisons. The new results reported in this work will enrich spectral database and are expected to be widely used in many fields.
通过将实验分支分数（BFs）与辐射寿命相结合，首次得出了 Eu I 的 16 个激发水平的 39 条线的过渡概率和振荡器强度。能量范围为 27852.90 至 41443.70 cm-1。在这项工作中，利用国家太阳观测站数据库中的傅立叶变换光谱确定了 BFs，并从文献中获得了寿命。此外，还测定了以前在文献中报道过的 22 条光谱线的 BFs，以进行比较。这项工作中报告的新结果将丰富光谱数据库，并有望在许多领域得到广泛应用。
{"title":"Determinations of transition probabilities and oscillator strengths of some levels in Eu I","authors":"Yuehua Chang , Qi Yu","doi":"10.1016/j.jqsrt.2024.109206","DOIUrl":"10.1016/j.jqsrt.2024.109206","url":null,"abstract":"<div><div>Through combining experimental branching fractions (BFs) with radiative lifetimes, transition probabilities and oscillator strengths of Eu I for 39 lines from 16 excited levels were derived for the first time. The energies range from 27852.90 to 41443.70 cm<sup>-1</sup>. The BFs were determined in this work using the Fourier transform spectra available from National Solar Observatory database, and the lifetimes were obtained from literature. Furthermore, BFs for 22 lines, previously reported in the literature, were also determined for comparisons. The new results reported in this work will enrich spectral database and are expected to be widely used in many fields.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"329 ","pages":"Article 109206"},"PeriodicalIF":2.3,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142423826","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 : 2024-09-25DOI: 10.1016/j.jqsrt.2024.109203
Salvador Bará , Raul C․ Lima
Wind farm lights are a conspicuous feature in the nocturnal landscape. Their presence is a source of light pollution for residents and the environment, severely disrupting in some places the aesthetic, cultural, and scientific values of the pristine starry skies. In this work we present a simple model for quantifying the visual impact of individual wind turbine lights, based on the comparison of their brightness with the brightness of well-known night sky objects. The model includes atmospheric and visual variables, and for typical parameters it shows that medium-intensity turbine lights can be brighter than Venus up to ∼4 km from the turbine, brighter than α CMa (the brightest star on the nighttime sky) until about ∼10 km, and reach the standard stellar visibility limit for the unaided eye (mv = +6.00) at ∼38 km. These results suggest that the visual range of wind farms at nighttime may be significantly larger than at daytime, a factor that should be taken into account in environmental impact assessments.
{"title":"Quantifying the visual impact of wind farm lights on the nocturnal landscape","authors":"Salvador Bará , Raul C․ Lima","doi":"10.1016/j.jqsrt.2024.109203","DOIUrl":"10.1016/j.jqsrt.2024.109203","url":null,"abstract":"<div><div>Wind farm lights are a conspicuous feature in the nocturnal landscape. Their presence is a source of light pollution for residents and the environment, severely disrupting in some places the aesthetic, cultural, and scientific values of the pristine starry skies. In this work we present a simple model for quantifying the visual impact of individual wind turbine lights, based on the comparison of their brightness with the brightness of well-known night sky objects. The model includes atmospheric and visual variables, and for typical parameters it shows that medium-intensity turbine lights can be brighter than Venus up to ∼4 km from the turbine, brighter than α CMa (the brightest star on the nighttime sky) until about ∼10 km, and reach the standard stellar visibility limit for the unaided eye (<em>m</em><sub>v</sub> = +6.00) at ∼38 km. These results suggest that the visual range of wind farms at nighttime may be significantly larger than at daytime, a factor that should be taken into account in environmental impact assessments.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"329 ","pages":"Article 109203"},"PeriodicalIF":2.3,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142423842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Pub Date : 2024-09-25DOI: 10.1016/j.jqsrt.2024.109198
Anna A. Simonova , Igor V. Ptashnik , Keith P. Shine
Water vapour continuum absorption is an important component of atmospheric radiative transfer codes. It significantly impacts the radiative balance of the atmosphere, but the physical nature of this absorption remains a subject of discussion. Here the H2O self-continuum absorption is considered within the infrared absorption bands (from 50 to 11 200 cm-1) of water vapour exploiting existing measurements. Comparison of this data with the MT_CKD-3.5 continuum model, which is used in many radiative transfer codes, reveals significant quantitative and qualitative differences. New water vapour self-continuum spectra are derived from earlier FTS measurements using HITRAN-2016 in the 5300 and 7200 cm-1 bands. A previously proposed water dimer model is refined and unified based on a broad set of up-to-date experimental data on the H2O continuum. The new model, which is suitable for incorporation into radiative transfer codes, has a much firmer physical basis than existing models. It reproduces the spectral behaviour and magnitude of the in-band water vapour self-continuum for temperatures from 279 to 431 K depending on the band. Importantly, the fitted total equilibrium dimerization constant used in the updated continuum model exceeds independent estimates by a factor of 1.5–3 across the entire temperature and spectral regions studied. Possible causes for this, which are important for understanding the physical origin of the continuum, are discussed. The contribution of water dimer to the continuum is estimated to vary from 40 to 90 % depending on absorption band and temperature.
{"title":"Semi-empirical water dimer model of the water vapour self-continuum within the IR absorption bands","authors":"Anna A. Simonova , Igor V. Ptashnik , Keith P. Shine","doi":"10.1016/j.jqsrt.2024.109198","DOIUrl":"10.1016/j.jqsrt.2024.109198","url":null,"abstract":"<div><div>Water vapour continuum absorption is an important component of atmospheric radiative transfer codes. It significantly impacts the radiative balance of the atmosphere, but the physical nature of this absorption remains a subject of discussion. Here the H<sub>2</sub>O self-continuum absorption is considered within the infrared absorption bands (from 50 to 11 200 cm<sup>-1</sup>) of water vapour exploiting existing measurements. Comparison of this data with the MT_CKD-3.5 continuum model, which is used in many radiative transfer codes, reveals significant quantitative and qualitative differences. New water vapour self-continuum spectra are derived from earlier FTS measurements using HITRAN-2016 in the 5300 and 7200 cm<sup>-1</sup> bands. A previously proposed water dimer model is refined and unified based on a broad set of up-to-date experimental data on the H<sub>2</sub>O continuum. The new model, which is suitable for incorporation into radiative transfer codes, has a much firmer physical basis than existing models. It reproduces the spectral behaviour and magnitude of the in-band water vapour self-continuum for temperatures from 279 to 431 K depending on the band. Importantly, the fitted total equilibrium dimerization constant used in the updated continuum model exceeds independent estimates by a factor of 1.5–3 across the entire temperature and spectral regions studied. Possible causes for this, which are important for understanding the physical origin of the continuum, are discussed. The contribution of water dimer to the continuum is estimated to vary from 40 to 90 % depending on absorption band and temperature.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"329 ","pages":"Article 109198"},"PeriodicalIF":2.3,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142423827","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 : 2024-09-20DOI: 10.1016/j.jqsrt.2024.109200
Mingjian Cheng , Yuancong Cao , Chenge Shi , Huan Zhang , Lixin Guo
This paper delves into the transmission dynamics of Bessel-Gaussian (BG) beams in three distinct dusty environments, leveraging the Generalized Lorenz-Mie Theory (GLMT) alongside a single scattering model for a comprehensive analysis. Through numerical simulations, the study explores the interaction between dust particle scattering and the attenuation and transmittance behaviors of BG beams, elucidating the influences of varying particle concentrations and visibility conditions typical of floating dust, blowing sand, and sandstorms. The findings reveal numerous determinants, including particle number concentration, optical visibility, wavelength, orbital angular momentum (OAM) modes, waist radius, cone angle, and polarization states, which significantly affect the transmission performance of BG beams in dusty conditions. Notably, the attenuation rate decreases with increasing wavelengths and higher OAM modes, thereby extending effective transmission distances. Furthermore, the strategic use of linear polarization emerges as an optimal approach for enhancing BG beam transmission efficiency in dust-rich environments. These insights are crucial for optimizing BG beam transmission in real-world applications, marking a significant advancement in the field.
{"title":"Investigation on the transmission attenuation of Bessel-Gaussian beams in a dusty environment","authors":"Mingjian Cheng , Yuancong Cao , Chenge Shi , Huan Zhang , Lixin Guo","doi":"10.1016/j.jqsrt.2024.109200","DOIUrl":"10.1016/j.jqsrt.2024.109200","url":null,"abstract":"<div><div>This paper delves into the transmission dynamics of Bessel-Gaussian (BG) beams in three distinct dusty environments, leveraging the Generalized Lorenz-Mie Theory (GLMT) alongside a single scattering model for a comprehensive analysis. Through numerical simulations, the study explores the interaction between dust particle scattering and the attenuation and transmittance behaviors of BG beams, elucidating the influences of varying particle concentrations and visibility conditions typical of floating dust, blowing sand, and sandstorms. The findings reveal numerous determinants, including particle number concentration, optical visibility, wavelength, orbital angular momentum (OAM) modes, waist radius, cone angle, and polarization states, which significantly affect the transmission performance of BG beams in dusty conditions. Notably, the attenuation rate decreases with increasing wavelengths and higher OAM modes, thereby extending effective transmission distances. Furthermore, the strategic use of linear polarization emerges as an optimal approach for enhancing BG beam transmission efficiency in dust-rich environments. These insights are crucial for optimizing BG beam transmission in real-world applications, marking a significant advancement in the field.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"329 ","pages":"Article 109200"},"PeriodicalIF":2.3,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142318979","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 : 2024-09-20DOI: 10.1016/j.jqsrt.2024.109193
Jesús Belmar , David Santalices , Shania Sánchez , Susana Briz, Juan Meléndez
In this study, we present a novel method for measuring unburned methane (CH) emissions in laboratory flames using mid-infrared hyperspectral imaging. Given the environmental significance of methane’s global warming potential, accurately quantifying emissions from combustion processes is critical. Our approach integrates an extended-area blackbody as the infrared source and a bandpass interference filter to mitigate issues of noise, low signal levels and detector saturation. This setup enabled high-resolution spectral analysis, capturing detailed concentration and temperature maps of methane around the flame. We tracked the dynamics of methane pockets escaping the flame using the hyperspectral imaging system in high-speed camera mode, providing insights into the behavior of unburned gases, such as the velocity of methane pockets. The study demonstrates the feasibility of this technique for assessing combustion efficiency by quantifying the flow of unburned methane through a control surface. Our findings suggest that mid-infrared hyperspectral imaging is a robust tool for remote sensing of methane emissions, offering significant advancements in the accurate measurement and analysis of combustion processes, and providing a benchmarking platform for measurement approaches intended for field applications.
{"title":"Measurement of unburned methane emissions in laboratory flames using mid-infrared hyperspectral imaging","authors":"Jesús Belmar , David Santalices , Shania Sánchez , Susana Briz, Juan Meléndez","doi":"10.1016/j.jqsrt.2024.109193","DOIUrl":"10.1016/j.jqsrt.2024.109193","url":null,"abstract":"<div><p>In this study, we present a novel method for measuring unburned methane (CH<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>) emissions in laboratory flames using mid-infrared hyperspectral imaging. Given the environmental significance of methane’s global warming potential, accurately quantifying emissions from combustion processes is critical. Our approach integrates an extended-area blackbody as the infrared source and a bandpass interference filter to mitigate issues of noise, low signal levels and detector saturation. This setup enabled high-resolution spectral analysis, capturing detailed concentration and temperature maps of methane around the flame. We tracked the dynamics of methane pockets escaping the flame using the hyperspectral imaging system in high-speed camera mode, providing insights into the behavior of unburned gases, such as the velocity of methane pockets. The study demonstrates the feasibility of this technique for assessing combustion efficiency by quantifying the flow of unburned methane through a control surface. Our findings suggest that mid-infrared hyperspectral imaging is a robust tool for remote sensing of methane emissions, offering significant advancements in the accurate measurement and analysis of combustion processes, and providing a benchmarking platform for measurement approaches intended for field applications.</p></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"329 ","pages":"Article 109193"},"PeriodicalIF":2.3,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0022407324003005/pdfft?md5=99a1deb019a74e1a4cf89ece27885de2&pid=1-s2.0-S0022407324003005-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142274206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
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