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Infrared spectroscopy (IR) is the most widely used analytical tool to quantify trace water in silicate and silica minerals. A prerequisite for highly accurate IR measurements of trace water is a good understanding of the effect of the second Si–O vibrational overtones/combination bands (2nd Si–O VOCBs) on the water peaks. Silicate and silica minerals can be divided as isolated (Q 0 ), paired (Q 1 ), ring (Q 2 ), chain (Q 1 or Q 2 ), sheet (Q 3 ) and framework (Q 4 ) structures according to the polymerization of their SiO 4 tetrahedral units, and the 2nd Si–O VOCBs of these different structural types attain different vibrational features which are expected to affect the water peaks to different extents. Here, we selected olivine (Q 0 ) and α -quartz (Q 4 ) as two endmember-like structural examples, performed extensive IR measurements on both pristine and heat-treated thin sections prepared for these two minerals, and explored the vibrational features of the 2nd Si–O VOCBs. We have found that the 2nd Si–O VOCBs are well separated from the water peaks in olivine, but severely overlap with the water peaks in α -quartz, confirming the different roles that the 2nd Si–O VOCBs play in quantifying trace water in silicate and silica minerals with different structural polymerizations. To remove the influence of the 2nd Si–O VOCBs (or any other species rather than water), an experimental protocol has been successfully developed, as approved by some fundamental equations and verified by the data of α -quartz in the literature. This development should lead to significant accuracy improvement in quantifying trace amounts of water in Earth and planetary materials.

In this paper, I will compare three reportative constructions: the French reportative conditional, Dutch zou + inf , and German sollen + inf . Although these markers share the reportative function as one of their established meanings, they clearly differ in how this reportative meaning actually functions. One of the most important differences pertains to the fact that the French conditional (and to a lesser extent Dutch zou + inf ) often combines reportative meaning with epistemic denial, i.e. the speaker distances him- or herself from the content of what he or she reports. German reportative sollen also allows for such distancing interpretations but to a much smaller extent. Specifically for this paper, I will look at the behaviour of the three markers in the immediate context of the noun ‘rumours’ (French rumeurs , Dutch geruchten , and German Gerüchte ), a context which – at least in theory – is strongly compatible with reportative marking, on the one hand, and with epistemic denial, on the other. On the basis of a self-compiled corpus of recent newspaper language, I will show that the French conditional occurs with a relatively high frequency in this specific context, especially in contrast to German sollen , and that the conditional often combines reportative semantics with epistemic denial, which again especially contrasts with German sollen + inf . Dutch zou + inf takes up an intermediate position in both respects.

Rayleigh waves are ubiquitously used for subsurface characterization through dispersion curve inversion, whose quality depends on the number of useable overtones. Traditional analysis is based on vertical receivers and, for active surveys, sources. However, for layered media, eigenfunction theory shows that optimal recovery of any given dispersion mode and frequency can be achieved by either vertical source‐vertical receiver or radial source‐radial receiver configurations, with source directivity being more dominant. Multi‐directional near‐surface wave‐equation modeling and field examples, including distributed acoustic sensing data, validate these predictions. Statistical analysis of compaction‐type near‐surface models shows that overtones are better recovered for radial‐radial surveys in large portions of the useable spectrum, extending beyond 60% for the second and above modes. We conclude that incorporating radial‐radial data acquisition is beneficial and should become standard procedure in active surveying, as well as analyzing the radial component in ambient noise and earthquake‐induced Rayleigh waves. Plain Language Summary Surface waves are a type of seismic wave that are often utilized for near‐surface characterization in a wide variety of fields. However, the quality of their recording is highly variable between different sites. By utilizing sources and receivers that generate and record energy in different directions, we can better excite these surface waves and facilitate their subsequent analysis. We show the benefits of directional surveys through mathematical, simulative and field data examples, and claim that they should become a widespread procedure in all fields relying on surface‐wave surveys. Key Points Radial and vertical directivity of sources and receivers strongly influences excitation of different Rayleigh‐wave dispersion modes Eigenfunction theory predicts the effect of survey directivity on recorded Rayleigh waves, also critical for distributed acoustic sensing Statistical analysis of near‐surface models shows significant improvement of overtone recovery by adding radial‐radial acquisition

This work was conducted using the Picoscope signal extraction procedure, which revealed significant insights regarding the belian wood and its application in Gendang Melayu Sarawak (GMS) production. The amplitude of belian wood GMS signal remains constant, allowing it to sustain its timbre for a longer duration compared to durian wood GMS using the same procedure. Considering that the dimensions of the big belian (BB) and big durian (BD) GMS are almost the same, both GMS yield almost the same note, i.e. G1# (51.9 Hz). Considering that the dimensions of both the small belian (SB) and small durian (SD) GMS are almost the same, both GMS yield almost similar note, i.e. F3 (174 Hz) and E3 (164 Hz). Although both BB and BD showed consistent harmonics, BD only displays 2 harmonics. The SB and SD both display consistent harmonics. Both BB and BD showed pleasing tonal qualities. These occurred due to the closeness of the principal overtones to the consonant interval.

Mimicry is a widespread phenomenon whereby predatory or parasitic individuals can access unsuspecting prey or hosts for the former’s benefit. For example, brood parasitic common cuckoos (Cuculus canorus) evolved several adaptations to trick hosts, including host-mimetic eggs, a barred chest plumage resembling the predatory Eurasian sparrowhawk (Accipiter nisus), and the female cuckoos’ bubbling calls considered as highly similar to this raptor’s calls. The sparrowhawk-like call mimicry is thought to threaten hosts while female cuckoos lay their eggs, although the similarity is restricted to the call’s fundamental frequency and not to its harmonics. However, these calls are also used in conspecific contexts, for example for mate attraction. If vocal mimicry is highly adapted toward the heterospecific function, it might cause reduced effectiveness in conspecific communication. We played cuckoo bubbling and sparrowhawk calls to territorial male cuckoos to test whether conspecific receivers process the mimetic calls accurately. All male cuckoos approached the speaker when female cuckoo calls were played, but rarely (7%) approached it when sparrowhawk or green woodpecker (Picus viridis; control) calls were played. When we excised the harmonic overtones from the sparrowhawk stimulus files, making these calls structurally more similar to the pure-tone female cuckoo calls, nearly half (43%) of the cuckoo males approached the speaker. Consequently, the difference in calls’ harmonic structure may explain one component of the inaccurate state of this acoustic mimicry. This imperfect mimicry by female cuckoos’ bubbling call to sparrowhawk call may ensure the multipurpose functions of this vocalization, including both intra- and interspecific contexts.Significance statementCommon cuckoos are obligate brood parasites, laying their eggs into other species’ nests. During laying, female cuckoos utter sparrowhawk-like vocalizations (bubbling calls), to threaten hosts and to evade their defenses. However, they also use this same call to communicate with other female and male cuckoos. If the bubbling call mimics closely sparrowhawks’ calls, cuckoos may also recognize and respond to the sparrowhawk call, the call of a predator, as a cuckoo call. We used playback experiments to show that cuckoos distinguished between bubbling and sparrowhawk calls in nearly all cases. When we manipulated sparrowhawk calls to be more similar acoustically to bubbling calls by deleting overtones, recognition errors increased from 7 to 43%. We conclude that mimicry of sparrowhawk calls by female cuckoo calls is imperfect, which allows it to function in cuckoo-cuckoo communication effectively.

Melamine (IUPAC: 1,3,5-Triazine-2,4,6-triamine) attracts high attention in analytical vibrational spectroscopy due to its misuse as a food adulterant. Vibrational spectroscopy [infrared (IR) and Raman and near-infrared (NIR) spectroscopy] is a major quality control tool in the detection and quantification of melamine content. The physical background for the measured spectra is not interpreted in analytical spectroscopy using chemometrics. In contrast, quantum mechanical calculations are capable of providing deep and independent insights therein. So far, the NIR region of crystalline melamine has not been studied by quantum mechanical calculations, while the investigations of its IR spectra have remained limited. In the present work, we employed fully anharmonic calculation of the NIR spectrum of melamine based on finite models, and also performed IR spectral simulation by using an infinite crystal model—periodic in three dimensions. This yielded detailed and unambiguous NIR band assignments and revised the previously known IR band assignments. We found that the out-of-plane fundamental transitions, which are essential in the IR region, are markedly more sensitive to out-of-plane inter-molecular interactions of melamine than NIR transitions. Proper description of the chemical surrounding of the molecule of melamine is more important than the anharmonicity of its vibrations. In contrast, the NIR bands mostly arise from in-plane vibrations, and remain surprisingly insensitive to the chemical environment. These findings explain previous observations that were reported in IR and NIR analytical studies of melamine.

Acoustic communication in obligate brood parasitic common cuckoos ( Cuculus canorus ) plays an important role both in social contacts within its own and with other species (including its many hosts). For example, the female cuckoo’s bubbling call putatively mimics the call of the Eurasian sparrowhawk ( Accipiter nisus ) to serve as defence from host songbirds mobbing the parasitic female. However, several other, both raptorial and harmless, sympatric bird species also have similar vocalizations to the bubbling call (including the Eurasian kestrel, Falco tinnunculus , and the Eurasian green woodpecker, Picus viridis ). Bubbling calls are also used by female cuckoos for conspecific communication with male conspecifics and so the discrimination of acoustically similar con- vs. heterospecific calls should be functionally relevant for cuckoos. We expanded upon a published playback study with all the above species’ calls presented to male cuckoos. The subjects approached the speaker in 100% when conspecific females’ bubbling calls were played back, but rarely (6–12%) did so when either acoustically similar natural calls of sympatric species were used. However, as structurally the bubbling call has no harmonic overtones, but the calls of the other species contain them, we also conducted playbacks with manipulated sound files where the harmonics were removed. Harmonic-free heterospecific calls attracted male cuckoos more often (40–50%) than natural heterospecific calls but still less so than the natural conspecific call. These results reveal the functional importance of the presence of harmonical overtones in heterospecific calls as they can serve to reduce perceptual auditory errors in male cuckoos.

The effect of isotopic substitution on near-infrared (NIR) spectra has not been studied in detail. With an exception of few major bands, it is difficult to follow the spectral changes due to complexity of NIR spectra. Recent progress in anharmonic quantum mechanical calculations allows for accurate reconstruction of NIR spectra. Taking this opportunity, we carried out a systematic study of NIR spectra of six isotopomers of ethanol (CX3CX2OX; X = H, D). Besides, we calculated the theoretical spectra of two other isotopomers (CH3CD2OD and CD3CH2OD) for which the experimental spectra are not available. The anharmonic calculations were based on generalized vibrational second-order perturbation theory (GVPT2) at DFT and MP2 levels with several basis sets. We compared the accuracy and efficiency of various computational methods. It appears that the best results were obtained with B2PLYP-GD3BJ/def2-TZVP//CPCM approach. Our simulations included the first and second overtones, as well as binary and ternary combinations bands. This way, we reliably reproduced even minor bands in the spectra of diluted samples (0.1 M in CCl4). On this basis, the effect of isotopic substitution on NIR spectra of ethanol was accurately reproduced and comprehensively explained.

Mid-infrared (MIR) and near-infrared (NIR) spectra of crystalline menadione (vitamin K3) were measured and analyzed with aid of quantum chemical calculations. The calculations were carried out using the harmonic approach for the periodic model of crystal lattice and the anharmonic DVPT2 calculations applied for the single molecule model. The theoretical spectra accurately reconstructed the experimental ones permitting for reliable assignment of the MIR and NIR bands. For the first time, a detailed analysis of the NIR spectrum of a molecular system based on a naphthoquinone moiety was performed to elucidate the relationship between the chemical structure of menadione and the origin of the overtones and combination bands. In addition, the importance of these bands during interpretation of the MIR spectrum was demonstrated. The overtones and combination bands contribute to 46.4% of the total intensity of menadione in the range of 3600–2600 cm−1. Evidently, these bands play a key role in shaping of the C-H stretching region of MIR spectrum. We have shown also that the spectral regions without fundamentals may provide valuable structural information. For example, the theoretical calculations reliably reconstructed numerous overtones and combination bands in the 4000–3600 and 2800–1800 cm−1 ranges. These results, provide a comprehensive origin of the fundamentals, overtones and combination bands in the NIR and MIR spectra of menadione, and the relationship of these spectral features with the molecular structure.

The infrared hydroxyl bands and first hydroxyl combination bands of glaucophane are characterized under pressure. In this weakly hydrogen-bonded mineral, the anharmonicity parameter, as determined from the difference between combinations and the fundamentals, is nearly constant with pressure to 15 GPa, indicating that the ambient pressure value of hydroxyl-bond anharmonicity closely reflects its value at high pressures. Given this near-constancy, the Grüneisen parameters of the hydroxyl stretching vibrations of a wide range of minerals, as derived from the pressure dependence of their O–H stretching frequencies, are correlated with the anharmonic parameter of each vibration, as determined from the ambient pressure offset of the summed frequencies of the fundamental n  = 0 to 1 transitions and the frequency of the hydroxyl combination or overtone band corresponding to the n  = 0 to 2 transition. This correlation is motivated by (1) the anharmonic origin of the Grüneisen parameter; and (2) the grossly similar form of the interatomic potential governing weak- and medium-strength hydrogen bonding in many minerals. This possible correlation provides a means through which the likely pressure-induced hydroxyl mode shifts of phases might be estimated from ambient pressure near-infrared measurements and emphasizes the importance of near-infrared combination/overtone band measurements. In this context, the combination/overtone bands of high-pressure hydrous phases are almost completely uncharacterized, and thus one probe of their anharmonicity has been neglected. Such information directly constrains the nature of hydrogen bonding in these phases, and hence provides possible insights into both their retention of hydrogen and its mobility. Deviations from the anharmonicity-Grüneisen parameter correlation, when observed (as may be the case in prehnite), could provide insights into anomalous effects on the hydroxyl potential well induced by bifurcated H-bonds, pressure-dependent Davydov splitting, or the influence of neighboring cations.