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This work studied the rovibrational absorption spectral line-shape parameters of the P(1)–P(10) and R(0)–R(9) lines for Hydrogen fluoride perturbed by argon in the 0–0, 1–0, and 2–0 vibrational bands at 20–1000 K. A dataset of beyond-Voigt line-shape parameters (pressure broadening and shifting parameters, their speed dependencies, and the complex Dicke parameters) has been theoretically determined for the first time from generalized spectroscopic cross-section calculated by the full quantum scattering calculations. Then these parameters were employed to predict the line shape and asymmetry based on the partially-correlated speed-dependent hard-collision and the partially-correlated quadratic-speed-dependent hard-collision profiles. The effect of each parameter on the line shape and line asymmetry was further studied, which revealed that the beyond-Voigt effects were indispensable to accurately describe the line shape contour. Our results are in good agreement with the available experimental observations and provide a comprehensive set of theoretical references for further experimental measurements. [ABSTRACT FROM AUTHOR]

The remote sensing of abundance and properties of HCl—the main atmospheric reservoir of Cl atoms that directly participate in ozone depletion—is important for monitoring the partitioning of chlorine between "ozone-depleting" and "reservoir" species. Such remote studies require knowledge of the shapes of molecular resonances of HCl, which are perturbed by collisions with the molecules of the surrounding air. In this work, we report the first fully quantum calculations of collisional perturbations of the shape of a pure rotational line in H35Cl perturbed by an air-relevant molecule [as the first model system we choose the R(0) line in HCl perturbed by O2]. The calculations are performed on our new highly accurate HCl(X1Σ+)–O2( X 3 Σ g − ) potential energy surface. In addition to pressure broadening and shift, we also determine their speed dependencies and the complex Dicke parameter. This gives important input to the community discussion on the physical meaning of the complex Dicke parameter and its relevance for atmospheric spectra (previously, the complex Dicke parameter for such systems was mainly determined from phenomenological fits to experimental spectra and the physical meaning of its value in that context is questionable). We also calculate the temperature dependence of the line shape parameters and obtain agreement with the available experimental data. We estimate the total combined uncertainties of our calculations at 2% relative root-mean-square error in the simulated line shape at 296 K. This result constitutes an important step toward computational population of spectroscopic databases with accurate ab initio line shape parameters for molecular systems of terrestrial atmospheric importance. [ABSTRACT FROM AUTHOR]

The predicted rotation-vibration absorption spectrum of the radioactive isotopically substituted water molecule, H214O, is presented. Variational nuclear-motion calculations are performed using the DVR3D software package based on the use of a high-precision potential energy function and an accurate dipole moment surface. Line centres, intensity and Einstein coefficients are calculated, and air pressure broadening coefficients are estimated. The calculation was carried out over a wide wavenumber range from 0 to 25000 cm $ {}^{-1} $ − 1 and total angular momentum up to J = 20. Isotopologue extrapolation rules based on experimental data on the energy levels of the stable isotopologues H216O, H $ {}_{2}^{16} $ 2 16 O H217O and H218O were also used to improve the predicted line positions. Spectral ranges best suited to the detection of H214O are identified. [ABSTRACT FROM AUTHOR]

We explore the prospects of laser-induced fluorescence diagnostics of nitric oxide (NO) using non-tunable fifth-harmonic radiation of a broad-band, ns-pulsed Nd:YAG laser at λ = 213 nm. Typically, 2–5 mJ/pulse of 213-nm radiation is produced by a commercial harmonic generator in this study, with an efficiency of about 1–3% (relative to the input pulse energy). We present spectral results obtained in various environments, ranging from air-based combustion processes at room conditions up to elevated pressure and temperature environments, the latter resembling conditions typical for compression-ignition internal combustion engines. In all cases, the laser-induced fluorescence spectrum shows clear signatures of the NO spectrum, mostly on transitions in the γ -band system ( A 2 Σ + → X 2 Π ). At higher fluences, multi-photon absorption also gives rise to blue-shifted fluorescence. The fluorescence yield increases with increasing pressure, allegedly due to non-resonant excitation, the efficiency of which increases with increasing pressure broadening. When applied to air-based combustion processes, interference by (hot) oxygen needs to be taken into account. We conclude that the method is a relatively straightforward option to visualize the NO distribution in a broad variety of applications. [ABSTRACT FROM AUTHOR]

Background: Migratory birds exhibit heterogeneity in foraging strategies during wintering to cope with environmental and migratory pressures, and gut bacteria respond to changes in host diet. However, less is known about the dynamics of diet and gut fungi during the wintering period in black-necked cranes (Grus nigricollis). Results: In this work, we performed amplicon sequencing of the trnL-P6 loop and ITS1 regions to characterize the dietary composition and gut fungal composition of black-necked cranes during wintering. Results indicated that during the wintering period, the plant-based diet of black-necked cranes mainly consisted of families Poaceae, Solanaceae, and Polygonaceae. Among them, the abundance of Solanaceae, Polygonaceae, Fabaceae, and Caryophyllaceae was significantly higher in the late wintering period, which also led to a more even consumption of various food types by black-necked cranes during this period. The diversity of gut fungal communities and the abundance of core fungi were more conserved during the wintering period, primarily dominated by Ascomycota and Basidiomycota. LEfSe analysis (P < 0.05, LDA > 2) found that Pyxidiophora, Pseudopeziza, Sporormiella, Geotrichum, and Papiliotrema were significantly enriched in early winter, Ramularia and Dendryphion were significantly enriched in mid-winter, Barnettozyma was significantly abundant in late winter, and Pleuroascus was significantly abundant in late winter. Finally, mantel test revealed a significant correlation between winter diet and gut fungal. Conclusions: This study revealed the dynamic changes in the food composition and gut fungal community of black-necked cranes during wintering in Dashanbao. In the late wintering period, their response to environmental and migratory pressures was to broaden their diet, increase the intake of non-preferred foods, and promote a more balanced consumption ratio of various foods. Balanced food composition played an important role in stabilizing the structure of the gut fungal community. While gut fungal effectively enhanced the host's food utilization rate, they may also faced potential risks of introducing pathogenic fungi. Additionally, we recongnized the limitations of fecal testing in studying the composition of animal gut fungal, as it cannot effectively distinguished between fungal taxa from food or soil inadvertently ingested and intestines. Future research on functions such as cultivation and metagenomics may further elucidate the role of fungi in the gut ecosystem. [ABSTRACT FROM AUTHOR]

MXenes, as emerging 2D sensing materials for next-generation electronics, have attracted tremendous attention owing to their extraordinary electrical conductivity, mechanical strength, and flexibility. However, challenges remain due to the weak stability in the oxygen environment and nonnegligible aggregation of layered MXenes, which severely affect the durability and sensing performances of the corresponding MXene-based pressure sensors, respectively. Here, in this work, we propose an easy-to-fabricate self-assembly strategy to prepare multilayered MXene composite films, where the first layer MXene is hydrogen-bond self-assembled on the electrospun thermoplastic urethane (TPU) fibers surface and the anti-oxidized functionalized-MXene (f-MXene) is subsequently adhered on the MXene layer by spontaneous electrostatic attraction. Remarkably, the f-MXene surface is functionalized with silanization reagents to form a hydrophobic protective layer, thus preventing the oxidation of the MXene-based pressure sensor during service. Simultaneously, the electrostatic self-assembled MXene and f-MXene successfully avoid the invalid stacking of MXene, leading to an improved pressure sensitivity. Moreover, the adopted electrospinning method can facilitate cyclic self-assembly and the formation of a hierarchical micro-nano porous structure of the multilayered f-MXene/MXene/TPU (M-fM2T) composite. The gradient pores can generate changes in the conductive pathways within a wide loading range, broadening the pressure detection range of the as-proposed multilayered f-MXene/MXene/TPU piezoresistive sensor (M-fM2TPS). Experimentally, these novel features endow our M-fM2TPS with an outstanding maximum sensitivity of 40.31 kPa−1 and an extensive sensing range of up to 120 kPa. Additionally, our M-fM2TPS exhibits excellent anti-oxidized properties for environmental stability and mechanical reliability for long-term use, which shows only ~0.8% fractional resistance changes after being placed in a natural environment for over 30 days and provides a reproducible loading–unloading pressure measurement for more than 1000 cycles. As a proof of concept, the M-fM2TPS is deployed to monitor human movements and radial artery pulse. Our anti-oxidized self-assembly strategy of multilayered MXene is expected to guide the future investigation of MXene-based advanced sensors with commercial values. [ABSTRACT FROM AUTHOR]

This work reports the full quantum calculations of the spectral line shape parameters for the P(22) line of 13CO and the P(31) line of 12CO in the fundamental band perturbed by He or Ar from 20 to 1000 K for the first time. The generalized spectroscopic cross sections of CO–He/Ar indicate that the Dicke narrowing effect competes with the pressure broadening effect. The pressure broadening can be explained by the dynamic behaviors of intermolecular collisions. The intermolecular inelastic collisions contribute more than 95% to the pressure broadening in both CO–He and CO–Ar systems at high temperatures. Regarding the state-to-state inelastic contributions to pressure broadening, the maximum contribution out of the final state of a given line is close to that out of the initial state. The Dicke narrowing effect influences the line shape profile significantly at high temperatures, which suggests that it is indispensable for reproducing the spectral line profile. With the Dicke narrowing effect, the calculated pressure-broadening coefficients and spectral intensity distribution are in good agreement with the available experimental observations. [ABSTRACT FROM AUTHOR]

This study deals with the broadening of atomic sodium, evolving in a neon buffer gas, in the wavelength and temperature ranges $ 500{\rm --}700\, {\rm nm} $ 500 − − 700 nm and $ 136{\rm --}3000\, {\rm K} $ 136 − − 3000 K , respectively. The computed emission and absorption spectral profiles are based on the most recent potential energy curves and transition dipole moments. The required electronic $ \mathrm {Na} (^{2}S) $ Na (2 S) $ +\mathrm {Ne}(^{1}S) $ + Ne (1 S) and $ \mathrm {Na}(^{2}P)+\mathrm {Ne}(^{1}S) $ Na (2 P) + Ne (1 S) potentials are used from two different sets. Then the satellite structures in the blue wing are analysed quantum mechanically. The calculations show especially that the free–free transitions contribute most to the NaNe photoabsorption spectra and a satellite structure is observable beyond the temperature $ 402\, {\rm K} $ 402 K around the wavelengths $ 550\, {\rm nm} $ 550 nm depending on the used potential set. The obtained results showed good agreement with those already published. [ABSTRACT FROM AUTHOR]

As the manufacturing industry evolves, the significance of control valve positioners in chemical production escalates. The flapper–nozzle system, the heart of control valve positioners, directly influences the linearity of system control. Presently, studies on the flapper–nozzle system primarily focus on dynamic system modeling and computational fluid dynamics simulations. However, traditional flapper–nozzle mechanisms often fail to achieve linear control objectives. This paper proposes a novel negative-pressure nozzle structure to tackle this issue, combining computational fluid dynamics and experimental methods, and considering gas compressibility during high-speed flow. Both simulation and experimental results suggest that the new structure improves the supply air pressure and broadens the linear pressure output range of the system, showing significant potential for practical applications. [ABSTRACT FROM AUTHOR]

Direct frequency comb spectroscopy was utilized to measure the vibrational absorption spectrum of diiodomethane, CH2I2, from 2960 to 3125 cm−1. The data were obtained using a CH2I2 concentration of (6.8 ± 1.3) × 1015 molecule cm−3 and a total pressure of 10–300 mbar with either nitrogen or argon as the bath gas. The rovibrational spectra of two fundamental transitions, ν6 and ν1, were recorded and analyzed. We suggest that a significant contribution to the observed congested spectra is due to the population in excited vibrational states of the low energy ν4 I–C–I bend, resulting in transitions 6104nn and 1104nn, where the integer n is the initial vibrational level v = 1–5. PGOPHER was used to fit the experimental spectrum, allowing for rotational constants and other spectral information to be reported. In addition, it was found that the peak widths for the observed transitions were limited by pressure broadening, resulting in a pressure broadening parameter of (0.143 ± 0.006) cm−1 atm−1 by N2 and (0.116 ± 0.006) cm−1 atm−1 by Ar. Further implications for other dihaloalkane infrared spectra are discussed. [ABSTRACT FROM AUTHOR]

The CO2 molecule is of great interest for astrophysical studies since it can be found in a large variety of astrophysical media where it interacts with the dominant neutral species, such as He, H2, or H2O. The CO2–He collisional system was intensively studied over the last two decades. However, collisional data appear to be very sensitive to the potential energy surface (PES) quality. Thus, we provide, in this study, a new PES of the CO2–He van der Waals complex calculated with the coupled-cluster method and a complete basis set extrapolation in order to provide rotational rate coefficients that are as accurate as possible. The PES accuracy was tested through the calculations of bound state transition frequencies and pressure broadening coefficients that were compared to experimental data. An excellent agreement was globally found. Then, revised collisional data were provided for the 10–300 K temperature range. Rate coefficients were compared to previously computed ones and are found to be up to 50% greater than previously provided ones. These differences can induce non-negligible consequences for the modeling of CO2 abundance in astrophysical media. [ABSTRACT FROM AUTHOR]

In light of its ubiquitous presence in the interstellar gas, the chemistry and reactivity of the HCO+ ion requires special attention. The availability of up-to-date collisional data between this ion and the most abundant perturbing species in the interstellar medium is a critical resource in order to derive reliable values of its molecular abundance from astronomical observations. This work intends to provide improved scattering parameters for the HCO+ and He collisional system. We have tested the accuracy of explicitly correlated coupled-cluster methods for mapping the short- and long-range multi-dimensional potential energy surface of atom–ion systems. A validation of the methodology employed for the calculation of the potential well has been obtained from the comparison with experimentally derived bound-state spectroscopic parameters. Finally, by solving the close-coupling scattering equations, we have derived the pressure broadening and shift coefficients for the first six rotational transitions of HCO+ as well as inelastic state-to-state transition rates up to j = 5 in the 5–100 K temperature interval. [ABSTRACT FROM AUTHOR]

Pressure engineering in semiconductors leads to a variety of novel physical phenomena and has recently received considerable attention. Here, we report on pressure-induced superconductivity in III–V gallium phosphide (GaP), a commercially important semiconductor that exhibits excellent optical performance. We show that the emergence of superconductivity is accompanied by the concurrence of piezochromic transition and metallization and can be correlated to a structural transition from the cubic to orthorhombic phase. In line with the structural origin of superconductivity, the critical temperature Tc monotonically decreases with increasing pressure up to ~50 GPa. Moreover, the superconductivity could be preserved toward ambient pressure because of the irreversibility of the structural transition. Nevertheless, the superconducting transition displays evident broadening associated with the presence of amorphization in the depressurized sample. The synchronous evolution of the structural and electronic properties not only shows a vivid structure-property relationship but also could facilitate the exploration of novel functionalities by means of pressure treatment. III-V commercial optical semiconductor GaP crystalizes in either zincblende or wurtzite structure at ambient pressure. Zincblende GaP transforms into orthorhombic phase across a critical pressure during compression, accompanying piezochromic transition, metallization and superconductivity. Upon decompression, superconductivity could be preserved toward ambient pressure and displays broadening features due to amorphization. It reveals the presence of two high-pressure superconducting phases. [ABSTRACT FROM AUTHOR]

Raman spectroscopy is a promising method to analyze natural gas. Measurement of hydrocarbon concentrations is required for quality control of this fuel. Despite the presence of intense characteristic peaks of hydrocarbons in the range of 2800–3040 cm−1, researchers avoid this region due to the overlap with a methane spectrum. This paper presents a simple method to simulate the Raman spectrum of methane in natural gas at different pressures and concentrations of nitrogen, carbon dioxide, and ethane. A detailed description of the algorithm and the empirical parameters necessary for the simulation are provided. The method can be used to improve the accuracy of the Raman gas analysis of natural gas and other methane‐bearing media. [ABSTRACT FROM AUTHOR]

With the existing pressure sensors, it is difficult to achieve the unification of wide pressure response range and high sensitivity. Furthermore, the preparation of pressure sensors with excellent performance for sleep health monitoring has become a research difficulty. In this paper, based on material and microstructure synergistic enhancement mechanism, a hybrid pressure sensor (HPS) integrating triboelectric pressure sensor (TPS) and piezoelectric pressure sensor (PPS) is proposed. For the TPS, a simple, low-cost, and structurally controllable microstructure preparation method is proposed in order to investigate the effect of carbon nano-onions (CNOs) and hierarchical composite microstructures on the electrical properties of CNOs@Ecoflex. The PPS is used to broaden the pressure response range and reduce the pressure detection limit of HPS. It has been experimentally demonstrated that the HPS has a high sensitivity of 2.46 V/104 Pa (50–600 kPa) and a wide response range of up to 1200 kPa. Moreover, the HPS has a low detection limit (10 kPa), a high stability (over 100,000 cycles), and a fast response time. The sleep monitoring system constructed based on HPS shows remarkable performance in breathing state recognition and sleeping posture supervisory control, which will exhibit enormous potential in areas such as sleep health monitoring and potential disease prediction. [ABSTRACT FROM AUTHOR]

Raman spectroscopy is a promising method to analyze natural gas. Measurement of hydrocarbon concentrations is required for quality control of this fuel. Despite the presence of intense characteristic peaks of hydrocarbons in the range of 2800–3040 cm−1, researchers avoid this region due to the overlap with a methane spectrum. This paper presents a simple method to simulate the Raman spectrum of methane in natural gas at different pressures and concentrations of nitrogen, carbon dioxide, and ethane. A detailed description of the algorithm and the empirical parameters necessary for the simulation are provided. The method can be used to improve the accuracy of the Raman gas analysis of natural gas and other methane‐bearing media. [ABSTRACT FROM AUTHOR]

In this article, I argue that the research field of religion and development and diaconal studies, the study of Christian social practice, share a common subject of inquiry: the social impact of religion. The field of religion and development investigates this mainly with a focus on the Global South and within the discursive framework of the concept of development, while diaconal studies has thus far taken a Christian perspective and a historic focus on the Global North. Recent paradigm shifts in the development discourse (post-development critique, 2030 Agenda for Sustainable Development as a global framework, critique of the secularist approach) put the field of religion and development under pressure to broaden its scope. Moreover, there is no clear lead discipline in the religion and development debate yet, raising questions about its disciplinary location in academic institutions and curricula. The field of diaconal studies is challenged by increasing religious pluralism and under pressure to consider perspectives from the Global South. Impulses from the recent advances in the conceptualisation of ecumenical diaconia as a new paradigm of Christian social service push the field to move beyond its historic focus on assistance and care. The aim of this article is to juxtapose these two fields of academic study and to bring them into mutual dialogue. The article reflects on both fields and their respective advantages and disadvantages and highlights areas of overlap. It goes on to propose a broadened discipline of diaconal studies, reshaped as the Study of Religious Social Practice, as a new academic field. The focus of this field would be the impact of religion on society in global perspective, across religious traditions and geographic contexts. [ABSTRACT FROM AUTHOR]

The pressure in an underwater discharge channel is the main parameter that influences all its applications. In this study, we investigate a relatively large gap with a plane-to-plane electrode geometry that uses the assistance of an injected gas bubble for breakdown. The delay in the application of high voltage following the injection of a gas bubble from a grounded electrode determines the initial dimensions of the bubble. We examined three types of discharge: (a) a large bubble with easy triggering, (b) a medium bubble, and (c) a small bubble with difficult triggering. The main diagnostic tool is H α line broadening. It is shown that (i) Doppler broadening plays no role; (ii) at pressure broadening, the resonance and van der Waals broadenings must be considered; (iii) the impact approximation is not applicable, and hence the quasi-static high-pressure (namely 'nearest neighbour') approximation must be used; and (iv) the Stark broadening plays the dominant role. Because a mixture of two gases (evaporated water vapour and nitrogen from bubble injection) is present in the discharge channel, simple thermodynamic considerations were applied to estimate the ratio of the contributions of resonance and van der Waals broadening. The larger the bubble, the smaller the pressure detected in the discharge channel. This is in agreement with the measurements of the pressure wave amplitude at a certain distance from the discharge channel using a piezoelectric pressure probe. [ABSTRACT FROM AUTHOR]

A new 3D-potential energy surface (3D-PES) for the weakly bound CH3Cl–He complex is mapped in Jacobi coordinates. Electronic structure calculations are performed using the explicitly correlated coupled clusters with single, double, and perturbative triple excitations approach in conjunction with the aug-cc-pVTZ basis set. Then, an analytical expansion of this 3D-PES is derived. This PES shows three minimal structures for collinear C–Cl–He arrangements and for He located in between two H atoms, in the plane parallel to the three H atoms, which is near the center of mass of CH3Cl. The latter form corresponds to the global minimum. Two maxima are also found, which connect the minimal structures. We then evaluated the pressure broadening coefficients of the spectral lines of CH3Cl in a helium bath based on our ab initio potential. Satisfactory agreement with experiments was observed, confirming the good accuracy of our 3D-PES. We also derived the bound rovibronic levels for ortho- and para-CH3Cl–He dimers after quantum treatment of the nuclear motions. For both clusters, computations show that although the ground vibrational state is located well above the intramolecular isomerization barriers, the rovibronic levels may be associated with a specific minimal structure. This can be explained by vibrational localization and vibrational memory effects. [ABSTRACT FROM AUTHOR]

We report fully quantum calculations of the collisional perturbation of a molecular line for a system that is relevant for Earth's atmosphere. We consider the N2-perturbed pure rotational R(0) line in CO. The results agree well with the available experimental data. This work constitutes a significant step toward populating the spectroscopic databases with ab initio collisional line-shape parameters for atmosphere-relevant systems. The calculations were performed using three different recently reported potential energy surfaces (PESs). We conclude that all three PESs lead to practically the same values of the pressure broadening coefficients. [ABSTRACT FROM AUTHOR]

A novel chirped-pulse Fourier transform microwave (CP-FTMW) spectrometer has been constructed to cover the Ka-band (26.5 GHz–40 GHz) for use in the CRESUCHIRP project, which aims to study the branching ratios of reactions at low temperatures using the chirped-pulse in uniform flow technique. The design takes advantage of recent developments in radio-frequency components, notably, high-frequency, high-power solid-state amplifiers. The spectrometer had a flatness of 5.5 dB across the spectral range, produced harmonic signals below −20 dBc, and the recorded signal scaled well to 6 × 106 averages. The new spectrometer was used to determine pressure broadening coefficients with a helium collider at room temperature for three molecules relevant to astrochemistry, applying the Voigt function to fit the magnitude of the Fourier-transformed data in the frequency domain. The pressure broadening coefficient for carbonyl sulfide was determined to be (2.45 ± 0.02) MHz mbar-1 at room temperature, which agreed well with previous measurements. Pressure broadening coefficients were also determined for multiple transitions of vinyl cyanide and benzonitrile. Additionally, the spectrometer was coupled with a cold, uniform flow from a Laval nozzle. The spectrum of vinyl cyanide was recorded in the flow, and its rotational temperature was determined to be (24 ± 11) K. This temperature agreed with a prediction of the composite temperature of the system through simulations of the experimental environment coupled with calculations of the solution to the optical Bloch equations. These results pave the way for future quantitative studies in low-temperature and high-pressure environments using CP-FTMW spectroscopy. [ABSTRACT FROM AUTHOR]

The second hyperpolarizability (γ) of the H2 molecule was measured by gas-phase electric field induced second harmonic generation at the frequencies of the one-photon resonance for the 3–0 Q(J) overtone transitions (v, J = 0, J → 3, J for J = 0, 1, 2, and 3). The magnitude of the resonant contribution to γ was measured with 2% accuracy using the previously determined non-resonant γ for calibration. Pressure broadening and frequency shift for the transitions were also measured. A theoretical expression for the resonant vibrational γ contribution in terms of transition polarizabilities is compared to the observations. The measured γ resonance strength is 4%–14% larger than the results obtained from this theoretical expression evaluated using ab initio transition polarizabilities. [ABSTRACT FROM AUTHOR]

Definition: Spectral lines in the optical spectra of atoms, molecules, and other quantum systems are characterized by a range of frequencies ω or a range of wavelengths λ = 2 π c / ω , where c is the speed of light. Such a frequency or wavelength range is called the width of the spectral lines (linewidth). It is influenced by many specific factors. Thermal motion of the molecules results in broadening of the lines as a result of the Doppler effect (thermal broadening) and by their collisions (pressure broadening). The electric fields of neighboring molecules lead to Stark broadening. The linewidth to be considered here is the so-called parametric broadening (PB) of spectral lines in the optical spectrum. PB can be considered the fundamental type of broadening of the electronic vibrational–rotational (rovibronic) transitions in a molecule, which is the direct manifestation of the basic concept of the collapse of a wavefunction that is postulated by the Copenhagen interpretation of quantum mechanics. Thus, that concept appears to be not only valid but is also useful for predicting physically observable phenomena. [ABSTRACT FROM AUTHOR]

The Super Separator Spectrometer-Low Energy Branch (S 3 -LEB) is a low-energy radioactive ion beam experiment under commissioning as part of the GANIL-SPIRAL2 facility. It will be used for the production and study of exotic nuclei by in-gas laser ionization and spectroscopy (IGLIS), decay spectroscopy, and mass spectrometry. We report recent results from the off-line commissioning of S 3 -LEB, including first laser spectroscopy measurements in both the gas cell and the supersonic gas jet, the determination of the transport efficiency of laser ions from the gas cell through the RFQ chain, and time-of-flight measurements with the multi-reflection time-of-flight mass spectrometer PILGRIM. The measurements were performed using erbium, introduced by evaporation from a heated filament in the gas environment. The reported laser spectroscopy results include a characterization of the pressure broadening in the gas cell, proof-of-principle isotope shift measurements, and hyperfine-structure measurements. [ABSTRACT FROM AUTHOR]

To develop remote isotopic analysis for the nuclides with small isotope shifts, Doppler-free fluorescence spectroscopy of Ca was performed using laser ablation plumes. Counter-propagating laser beams from two external cavity diode lasers were used to irradiate the plume in order to excite the ground-state Ca atoms to the 1D2 state through a double resonance scheme of 1S0 → 1P1 → 1D2. Subsequently, we measured fluorescence spectra associated with the relaxation from the 1D2 to 1P1 states. The linewidth measured at 1 ms delay after ablation under helium gas pressure of 70 Pa was found to be less than 70 MHz, which was about 1/30 of the linewidth of the Doppler-limited fluorescence spectrum. A broad Gaussian pedestal was observed at less than 600 μs delay in the temporal variation in fluorescence spectra, and it was most likely due to the velocity-changing collision. Additionally, the pressure broadening rate coefficient for the second-step 1P1 → 1D2 transition was determined to be 46.0 MHz per torr from the spectra measured under various gas pressures. We evaluated analytical performances such as linearity of the calibration curve, limit of detection, and measurement accuracy using fluorescence signals of three naturally occurring Ca isotopes (i.e., 40Ca, 42Ca, and 44Ca). The limit of detection of isotopic abundance was estimated to be 0.09% from the 3σ criteria of the background. These results suggest that this spectroscopic technique is promising for remote isotopic analysis of nuclides with small isotope shifts. [ABSTRACT FROM AUTHOR]

The temperature of the alkali metal cell, which affects the density of the alkali-metal vapor and the gas pressure, is usually difficult to measure directly. However, the temperature of the alkali-metal cell and the density of the alkali-metal vapor are important parameters that affect the performance of the atomic sensor. In this paper, a device that can directly measure the internal temperature of an alkali metal cell in real time is designed for the first time to explore the relationship between alkali-metal vapor density and temperature. Alkali-metal vapor density is measured using the absorption spectrum. The pressure broadening model, combined with the transition of four hyperfine levels, was used to fit the absorption line of 87Rb D1 under the action of 700 Torr N2, and a good fitting effect was obtained. The experimental results show that the density of 87Rb is less than the value calculated by the empirical formula. Based on the experimental results, we give the calculation formula of 87Rb density with an uncertainty of only 4% and obtain the temperature dependence index of the line width and linear displacement of 87Rb in N2 by analyzing the absorption spectrum. [ABSTRACT FROM AUTHOR]

A tunable diode laser absorption spectroscopy (TDLAS)-based spectrometer employing a mid-infrared (Mid-IR) interband cascade laser (ICL) was developed and used to determine pressure broadening coefficients of two NO absorption transitions at 1914.98 cm−1 and 1915.76 cm−1 in the fundamental (1←0) band (R11.5 Ω1/2 and Ω3/2) for CO2, N2, Ar, O2, He, and H2. For the first time, a reliable and consistent set of six different pressure-broadening coefficients for the NO line has been measured by a consistent approach covering pressures from 100 to 970 mbar at a temperature of 294 K. Air pressure broadening has been calculated based on N2 and O2 coefficients. The stated pressure-broadening coefficients for N2, CO2, Ar, H2, O2, He, and Air have relative errors in the 0.5–1.5% range. For CO2 and H2, broadening results of NO (1←0) band (R11.5 Ω1/2 and Ω3/2) lines are reported for the first time. The results are also compared to previously available literature data. It was found that the broadening coefficients for O2 and Air are in agreement with literature values, whereas results for Ar and He show larger differences. [ABSTRACT FROM AUTHOR]

The CoFe2O4/La0.7Sr0.3MnO3 composites with the La0.7Sr0.3MnO3 mass ratio of 18% was prepared by solid state reaction method, and the magnetic properties under pressure (P) were studied. As P < 0.21 GPa, the grain spacing was reduced by the pressure, resulting in the simultaneous enhancement of the exchange coupling interaction and the dipole interaction between the grains. The results are as follows: (1) the temperature region (ΔT) in which the exchange coupling dominates in the field-colding magnetization (MFC) curve broadens with the pressure. (2) The MFC value at 10 K, i.e., MFC(10 K) increases with pressure. (3) The difference between the zero-field-colding magnetization (MZFC) as P > 0 and as P = 0 was denoted as ΔMZFC(T); it shows the result of ΔMZFC(T) > 0, i.e., the pressure increases the magnetization. Moreover, the values of ΔMZFC(T) increases with the increase in pressure. As P > 0.21 GPa, ΔT and MFC(10 K) hardly change with the pressure; the ΔMZFC(T) curve approximately coincides; the strength of inter-grain exchange-coupling hardly changes with the pressure. These results show that the 0.21 GPa pressure compresses the grain spacing to the greatest degree, and the magnetic moments between grains or within the grain boundaries were arranged in parallel to the greatest extent. In addition, the paramagnetic-ferromagnetic transition temperature Tc of La0.7Sr0.3MnO3 in the composite changes faster with pressure than the Tc of the single-phase La0.7Sr0.3MnO3 sample does. Finally, the pressure can improve the magnetic performance; specifically, the 0.21 GPa pressure increases the saturation magnetization Ms and the remanence ratio Mr/Ms by 3.5% and 17.9%, due to the contribution of grain boundary magnetization. [ABSTRACT FROM AUTHOR]

Recently, advanced ab initio computations were used to generate the three-dimensional potential energy surface (3D-PES) of the phosphine–He (PH3–He) van der Waals complex along the intermonomer coordinates. This 3D-PES describes correctly the complex features of the intermolecular interactions between PH3 and He, which are on the origin of pressure broadening phenomena. At present, we take advantage of this accurate 3D-PES to compute the phosphine line broadenings perturbed by He at room temperature. First, we adjusted this 3D-PES by a new ‘fractional’ function in order to be able to incorporated it into our collisional broadening calculation code. Then, we considered the semi-classical model of Modified Robert and Bonamy improved by so-called the notion of exact trajectory to deduce the He-broadening coefficients of phosphine lines at room temperature. Room temperature data are given in the case of different branches of the parallel, ν2, and perpendicular, ν4, PH3 vibrational bands. Our results show an improved agreement with the experimental measurements. This work should be of great help for the precise determination of PH3 abundances in planetary atmospheres spectra. [ABSTRACT FROM AUTHOR]

• Homogeneous pulsed laser deposition of PCMO on 4″ wafer. • Addressing the issue of plume broadening by a slit system. • Deposition strategy development with simulation software. • Area-dependent memristive switching of PCMO /AlO x heterostructures. • Process temperature is compatible with back end of line integration into standard CMOS technology. Heterostructures of the perovskite Pr 0.7 Ca 0.3 MnO 3 (PCMO) and a tunnel oxide such as AlO x are highly interesting memristive devices for emulating synaptic properties in neuromorphic circuits. Future chip generations with these memristive elements requires PLD systems which enables PCMO growth on a full wafer. To address the issue of plume broadening in this study, a slit system was used to localize the deposition region, thereby eliminating the need for excessive scanning. This study investigates the effect of the slit system and process gas pressure on plume broadening. This investigation has been used to parameterize a simulation software to assess the effectiveness of different movement speeds and to develop strategies for homogeneous deposition, adjustable to a chosen film thickness in the order of twenty nanometers. We used these strategies to fabricate area dependent switching memory cells on a standard 4″ Si wafer using the material combination of Pr 0.7 Ca 0.3 MnO 3 and AlO x. The influence of the aluminum oxide thickness on the switching shows that the IV loop starts to exhibit a hysteresis for AlO x thicknesses ≥ 3 nm. An increase in AlO x thickness leads to an increase in resistance and capacitive charging. An additional thermal treatment reduces the resistance and the switching voltage and increases the ratio between low resistive and high resistive state. Devices without thermal treatment of the PCMO are compatible for back end of line processing of standard CMOS technology. [ABSTRACT FROM AUTHOR]

Despite its key role for the study and modeling of nitrogen chemistry and NOx formation in combustion processes, HCN has only rarely been detected under high-temperature conditions. Here, we demonstrate quantitative detection of HCN behind incident and reflected shock waves using a novel sensitive single-tone mid-infrared frequency modulation (mid-IR-FM) detection scheme. The temperature-dependent pressure broadening of the P(26) line in the fundamental CH stretch vibration band was investigated in the temperature range 670K≤T≤1460K, yielding a pressure broadening coefficient for argon of 2γAr296K=(0.093±0.007)cm−1atm−1 and a temperature exponent of nAr=0.67±0.07. The sensitivity of the detection scheme was characterized by means of an Allan analysis, showing that HCN detection on the ppm mixing ratio level is possible at typical shock wave conditions. In order to demonstrate the capability of mid-IR-FM spectroscopy for future high-temperature reaction kinetic studies, we also report the first successful measurement of a reactive HCN decay profile induced by its reaction with oxygen atoms.

Precipitation and its response to forcing is an important aspect of planetary climate system. In this study, we examine the strength of precipitation in the experiments with different atmospheric masses and their response to surface warming, using three global atmospheric general circulation models and one regional cloud‐resolving model. We find that precipitation is weaker when atmospheric mass is larger for a given surface temperature. Furthermore, the increasing rate of precipitation with increasing surface temperature under a larger atmospheric mass is smaller than that under a smaller atmospheric mass. These behaviors can be understood based on atmospheric or surface energy balance. Atmospheric mass influences Rayleigh scattering, multiple scattering in the atmosphere, pressure broadening, lapse rate, and thereby precipitation strength. These results have important implications on the climate and habitability of early Earth, early Mars, and exoplanets with oceans. Plain Language Summary: Precipitation is one of the key variables of the planetary climate system. Many factors can influence the strength of precipitation, such as solar flux, land‐sea distribution, greenhouse gases, and aerosols. In this study, we show that another factor, atmospheric mass, can also strongly influence precipitation. The strength of precipitation increases with increasing surface temperature but decreases with increasing atmospheric mass. Furthermore, the increasing rate of precipitation with surface temperature becomes smaller under a larger atmospheric mass. These results have important implications for the climate evolution of early Earth, early Mars, and extra‐solar rocky planets, which may have higher or lower air mass than that of modern Earth. Key Points: Numerical simulations show that under a given surface temperature, the precipitation is weaker if the air mass is largerThe increasing rate of global‐mean precipitation with surface temperature under a larger air mass is also smallerThe combined effect of air mass on Rayleigh scattering, multiple scattering, pressure broadening, and lapse rate is the mechanism [ABSTRACT FROM AUTHOR]

As the development of current propulsion technology such as gas turbine and rocket chamber moving to higher working pressure, the radiative parameters of fuel, such as CH4 or CO, are required at elevated pressures, which in some cases are calculated without considering the pressure effect of line broadening. To investigate the pressure effect of line broadening on the radiative heat transfer, the radiative heat sources of a 1-D enclosure filled with CH4/CO and Planck mean absorption coefficients at elevated pressures were calculated using the statistical narrow band and line-by-line methods. The radiative parameters were conducted using high temperature molecular spectroscopic (HITEMP) 2019 (for CO) and HITEMP 2020 (for CH4) databases. The results showed that the pressure effect of line broadening on the calculations of radiative heat source of CH4 can be ignored when HITEMP 2020 database was used. For CO medium, the pressure effect of line broadening was over 40% at 30 atmosphere in all cases whichever methods and databases were used. The pressure broadening has a strong effect on the Planck mean absorption coefficient below 1000 K for CH4 and at the temperature of 500-900 K for CO at 30 atmosphere. The maximum pressure effects were 22% for CH4 and 18% for CO at 30 atmosphere, which illustrated the pressure effect of line broadening needed to be taken into account in the calculation of Planck mean absorption coefficient. [ABSTRACT FROM AUTHOR]

[Display omitted] • Measure pressure broadening coefficients perturbed by Air, O 2 , N 2 , He, CO 2 , CH 4 , and H 2 and line intensities of six NH 3 transitions near 1084.6 cm−1. • Develop an NH 3 -OGS to address NH 3 impurity requirements outlined in ISO/EU standards for CCUS, Biomethane and H 2. • The NH 3 -OGS has an uncertainty of 1.35 %, a precision of 800 ppt (integration time: 10 s), and a repeatability of 130 ppt (measurement time: 48 min). • The NH 3 -OGS addresses nonlinear NH 3 adsorption–desorption dynamics, underscoring its potential as a calibration-free and SI-traceable metrological gas analysis instrument. A mid-infrared quantum cascade laser (Mid-IR QCL) coupled with a Single Pass Cell and a Multi Pass Cell, was utilized to measure ammonia (NH 3) absorption spectroscopic parameters and determine NH 3 impurities toward three emerging applications. We for the first time measured the pressure broadening coefficients perturbed by Air, O 2 , N 2 , He, CO 2 , CH 4 , and H 2 and the line intensities of six NH 3 transition lines near 1084.6 cm−1. The measured NH 3 -He, NH 3 -Air, and NH 3 -CO 2 broadening coefficients align with HITRAN database, while NH 3 -H 2 coefficients exhibit a maximum discrepancy of 46 %. Deviations between the measured line intensities and HITRAN database are minimal. Nevertheless, the uncertainties of line intensities have been significantly reduced from 20 % in HITRAN to below 3 %. The newly measured line parameters are utilized to address NH 3 impurity requirements outlined in CCUS (ISO 27913:2016), Biomethane (EN 16723:2016), and H 2 (ISO 14687:2019) standards. Based on the concept of optical gas standard (OGS), the NH 3 impurity detection requirements in all three standards have been fulfilled with an uncertainty of 1.35 %. The precision of the NH 3 -OGS is 800 part per trillion (ppt) with an integration time of 100 s. The repeatability of the NH 3 -OGS is 130 ppt for a continuous measurement time of 48 min. Notably, the NH 3 -OGS effectively addresses the highly nonlinear adsorption–desorption dynamics, underscoring the potential of OGS as a calibration-free and SI-traceable metrological gas analysis instrument. [ABSTRACT FROM AUTHOR]

The ExoMol database (www.exomol.com) provides molecular data for spectroscopic studies of hot atmospheres. These data are widely used to model atmospheres of exoplanets, cool stars and other astronomical objects, as well as a variety of terrestrial applications. The 2024 data release reports the current status of the database which contains recommended line lists for 91 molecules and 224 isotopologues giving a total of almost 1012 individual transitions. New features of the database include extensive "MARVELization" of line lists to allow them to be used for high resolutions studies, extension of several line lists to ultraviolet wavelengths, provision of photodissociation cross-sections and extended provision of broadening parameters. Some of the in-house data specifications have been rewritten in JSON and moved for conformity with other international standards. Data products, including specific heats, a database of lifetimes for plasma studies, and the ExoMolHR web app which allows exclusively high resolution data to be extracted, are discussed. [Display omitted] [ABSTRACT FROM AUTHOR]

We present the results of the spectral line-shape study of the first measurement of the extremely weak (7–0) band of the 12C16O molecule. Measurements were done with a highly sensitive cavity ring-down spectrometer. Collisional narrowing, analyzed in terms of speed-dependent effects, was observed for the first time for transitions with line intensities below 2 ⋅ 1 0 − 29 cm/molecule at 296 K. We provide a full set of line-shape parameters of the speed-dependent and regular Voigt profile analysis for 14 transitions from P and R branches. Experimental verification of a strong vibrational dependence of the pressure shifting described by the Hartmann model (Hartmann, 2009) is extended up to the sixth overtone highly sensitive to the model parameter. [Display omitted] • The first line-shape study of the extremely weak (7–0) band of the 12C16O molecule. • Speed-dependent effects observed for transitions with intensities below 2 ⋅ 1 0 − 29 cm/molecule. • Full set of line-shape parameters of the speed-dependent and regular Voigt profile analysis. • Experimental verification of a strong vibrational dependence of the pressure shifting described by the Hartmann model. [ABSTRACT FROM AUTHOR]

The in situ analysis of natural gas is one of the most promising applications of Raman spectroscopy. It is necessary to take into account the pressure effect on the spectrum of methane to improve the accuracy of this technique. This study aimed to develop and verify two methods for simulating the ν2 Raman band of methane at any spectral resolution and pressure. The first method was based on the use of the spectroscopic parameters of each single line (position, intensity, broadening, and shift coefficient). The second one was based on the use of the spectral profiles, each of which replaces a group of lines. The data required for the implementation of each method are presented in this work. A comparison of the calculated and measured spectra with a resolution of ~0.5 and ~7 cm−1 was performed. It was shown that the differences do not exceed 5% for each method in the range of 1–60 atm. [ABSTRACT FROM AUTHOR]

In response to an external stimulus, the cochlea emits sounds, called stimulus frequency otoacoustic emissions (SFOAEs), at the stimulus frequency. In this article, a three-dimensional computational model of the gerbil cochlea is used to simulate SFOAEs and clarify their generation mechanisms and characteristics. This model includes electromechanical feedback from outer hair cells (OHCs) and cochlear roughness due to spatially random inhomogeneities in the OHC properties. As in the experiments, SFOAE simulations are characterized by a quasiperiodic fine structure and a fast varying phase. Increasing the sound pressure level broadens the peaks and decreases the phase-gradient delay of SFOAEs. A state-space formulation of the model provides a theoretical framework to analyze the link between the fine structure and global modes of the cochlea, which arise as a result of standing wave resonances. The SFOAE fine structure peaks correspond to weakly damped resonant modes because they are observed at the frequencies of nearly unstable modes of the model. Variations of the model parameters that affect the reflection mechanism show that the magnitude and sharpness of the tuning of these peaks are correlated with the modal damping ratio of the nearly unstable modes. The analysis of the model predictions demonstrates that SFOAEs originate from the peak of the traveling wave. [ABSTRACT FROM AUTHOR]

The alkali-metal vapor cell is the key sensitive element of quantum sensors such as atomic magnetometers, atomic gyroscopes, and atomic clocks. The alkali-metal vapor in the cell interacts with laser and magnetic field to achieve high-precision measurement of some physical quantities. A teaching experiment platform for parameter testing of alkali-metal vapor cells with high temperature and high pressure is constructed. According to the measured laser absorption spectrum, the pressure of the buffer gas and the density of alkali-metal atoms inside the vapor cell can be obtained. This experimental platform help students to directly observe the interaction between laser and atoms, which helps them to understand the alkali-metal vapor cell, cultivate their experimental hands-on ability and provides support for graduate and undergraduate related courses. [ABSTRACT FROM AUTHOR]

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Flexible metal–organic framework (MOF) materials have the ability to perform stimulated sudden volume contractions, and thus attract increasing attention for use in potential applications such as: actuators or sensors. Here, the structural transition of MIL-53(Cr) loaded with a high concentration of CH3OH (CH3OH) guest molecules, which cause internal pressure due to guest–guest interactions, was investigated. The pressure triggering the structural transition can be enhanced by high guest molecule loadings (1 CH3OH per unit cell (UC): 5 MPa, empty: 53 MPa, 7 CH3OH per UC: 90 MPa, and 8 CH3OH per UC: 280 MPa). The asymmetrical and small distortion of the organic–inorganic connections are the main microscopic characteristic of the structural transition of MIL-53(Cr) with a high CH3OH loading. The external pressure and the internal pressure, instead of the adsorption of the guest molecules, became dominant in the structural transition of MIL-53(Cr). Current studies showed that the high-pressure response of the flexible MOF structure may broaden the acceptable pressure range in future actuator or sensor applications. [ABSTRACT FROM AUTHOR]

The two-photon excitation cross-section is a key parameter for the two-photon absorption laser induced fluorescence (TALIF) method, which is commonly used to measure atomic densities in gaseous media, especially for plasma diagnostics. The method consists in recording the fluorescence signal that follows the resonant absorption of two photons of UV light. Calibration often relies on comparing the signal recorded in the studied sample with the fluorescence produced, at a similar wavelength, in a noble gas vapor, the density of which can be easily known. The ratio of the involved cross-sections however plays an essential role for the accuracy of such measurements. Yet the two-photon excitation cross-section of atomic xenon, which is often used as the reference for oxygen density measurements, was measured only once, at the wavelengths of interest. The aim of the present study has been to consolidate the experimental value of that key parameter. The cross-section is found equal to and for the 6p′[3/2]2 and 6p′[1/2]0 levels, respectively. For the 6p′[3/2]2 level this is more than twice smaller than previously admitted. Even though the necessarily large relative uncertainty of a non-linear cross-section attaches a relatively large uncertainty to this factor of one half, the result suggests that atomic densities already measured by Xe-calibrated TALIF may have to be revised to significantly lower values. The experiments performed also provide an opportunity to revisit the validity of the approximations used for quantitative TALIF measurements and the collisional broadening and pressure shift of the two-photon 6p′[1/2]0 line. A new formula has been used to describe the two-photon absorption of a Gaussian beam in a long gas cell, which makes the decrease of the beam intensity a simple analytic expression even in strong absorption regime, based on a polylogarithmic function of the absorption rate variable. [ABSTRACT FROM AUTHOR]

We determine the CO2, N2, Ar, O2 and air pressure broadening coefficients of the H35Cl P(5) absorption line at 2775.77 cm−1 in the fundamental (1←0) band using a newly developed direct tunable diode laser absorption spectroscopy (dTDLAS)-based spectrometer employing a mid-IR interband cascade laser (ICL). For the first time, a reliable and consistent set of five different foreign pressure broadening coefficients for the same HCl P(5) line has been measured by a consistent metrological approach covering pressures from 100 to 600 hPa at temperatures of 294 and 295 K. The relative uncertainties of the stated CO2, N2, Ar, O2 and Air pressure broadening coefficients are in 1–3% range. The results are compared to previously available literature data—two broadening coefficients have been improved in accuracy and two have been determined for the first time in the sub 1000 hPa pressure range. [ABSTRACT FROM AUTHOR]

A new pressure-calibration method for calibrating the reduction of second harmonic (2f) amplitude caused by pressure broadening effect in sealed microbial growth environment is present. The new method combines with linewidth compensation and modulation depth compensation and makes the 2f amplitude accurately retrieve metabolic CO2 in microbial growth. In order to verify the method, a simulation experiment is developed, in which the increasing CO2 concentration leads to the increasing pressure. Comparing with the relation between the traditional 2f amplitude and gas concentration, there is a monotonous relation between the calibrated 2f amplitude and CO2 concentration, particularly, a linear relation is present when the CO2 concentration is replaced with the CO2 particle number. In terms of microbial measurement, the growth of Escherichia coli is measured, and the culture bottle is sealed during the microbial growth process. The experimental results show that, comparing to the microbial growth retrieved by traditional 2f amplitude, the calibrated 2f amplitude can accurately retrieve microbial growth in sealed environment. [ABSTRACT FROM AUTHOR]

Spectral broadening is an important nonlinear effect during the interaction of intense femtosecond laser pulses with air. In this paper, we experimentally study the dependence of spectral broadening on pressure and pulse energy. It is found that increasing both pressure and pulse energy can enhance the spectral intensity, while only increasing pressure leads to obvious blue shift of spectra, and the pulse energy has little effect on it. To get a better insight of the mechanism of spectral broadening, the numerical simulation relating the instantaneous frequency to the time dependent pulse intensity and time dependent plasma density in air is carried out. The results indicate that the plasma generation induced self-phase modulation which is related to the pressure plays an important role in blue shift of spectrum. Besides the transmission of the laser pulse is measured and decreases with pressure. It proves that the energy transfer of the laser pulse is promoted by pressure. This study will be helpful to understand a deeper physical mechanism of femtosecond filament induced supercontinnum generation in air. [ABSTRACT FROM AUTHOR]

Correct pressure broadening is essential for modelling radiative transfer in atmospheres, however data are lacking for the many exotic molecules expected in exoplanetary atmospheres. Here we explore modern machine learning methods to mass produce pressure broadening parameters for a large number of molecules in the ExoMol data base. To this end, state-of-the-art machine learning models are used to fit to existing, empirical air-broadening data from the HITRAN database. A computationally cheap method for large-scale production of pressure broadening parameters is developed, which is shown to be reasonably (69%) accurate for unseen active molecules. This method has been used to augment the previously insufficient ExoMol line broadening diet, providing air-broadening data for all ExoMol molecules, so that the ExoMol database has a full and more accurate treatment of line broadening. Suggestions are made for improved air-broadening parameters for species present in atmospheric databases. [Display omitted] • A machine learning model is trained on the air-broadening data available in the HITRAN database. • A 69% reproduction of the HITRAN data within stated uncertainties is achieved. • Improvements in air broadening data are suggested for some species. • The algorithm is used to populate the ExoMol database. [ABSTRACT FROM AUTHOR]

Close coupling calculations of line shape parameters have been performed for the first pure rotational Raman S 0 (j = 0 − 3) lines of CO in an H 2 bath. The pressure broadening coefficients obtained are in good agreement with the experimental values recently measured at 77, 180 and 298 K by some of us. The quantum dynamical calculations allow us to also determine line shift and Dicke parameters over a wide range of temperatures (20 to 400 K) for these lines. In addition, acquisitions of Raman spectra of the fundamental vibrational Q branch of CO in H 2 have been performed allowing the determination of pressure broadening and line mixing coefficients for the first lines of the band at 77, 195 and 298 K. Based on our calculated pure rotational rate constants, we have also deduced pressure broadening and line mixing coefficients for these rovibrational lines. Theoretical values compare reasonably well with the set of experimental data. • Pressure broadening coefficients induced by H 2 for Q lines of the 0-1 band of CO. • Temperature dependence of these pressure broadening coefficients. • Line mixing between the first Q(j) lines of CO in H 2. • Investigation of line shape parameters for pure rotational CO S lines in H 2. • As expected small beyond-Voigt effects for CO lines in H 2. [ABSTRACT FROM AUTHOR]