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91.
Pressure variation of maximumF-band absorption energies in the halides of lithium, sodium and potassium has been investigated employing the extended-ion
approximation for the calculation of theF-electron energy eigenvalues and using values of local compressibility in the neighbourhood of theF-centres which include the effect of vacancy and pressure. The results obtained agree with the experimental results. 相似文献
92.
The experimental results obtained from a study of post-stimulatory masking phenomena are summarized. Two mechanisms are postulated to explain these results. A model, based on these two mechanisms, is derived, and comprises the input from the auditory senses, on which preliminary decisions and actions are taken, followed by a selective filter and limited capacity channel leading to the higher brain centres which can effect overriding control on the system. This model is used to provide explanations of the experimental results obtained in this study. 相似文献
93.
Theoretical treatments of the distorted square pyramidal co-ordination observed in vanadyl β-keto-enolates predict restricted interligand conjugation and minimal π-interaction in the oxovanadium-ligand bonds. The effects of ligand substitution on the vibrational and electronic spectra of vanadyl β-keto-enolates yield evidence that strong σ-bonding and ionic contributions are chiefly responsible for the strong vanadium-ligand bonding. 相似文献
94.
95.
Caroline Price Udo Drfler John D. Kennedy Mark Thornton‐Pett 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(5):600-601
The title compound, 6‐pyridyl‐4‐aza‐arachno‐nonaborane(11), C5H16B8N2, has an arachno nine‐vertex {4‐NB8H11} cluster structure with a pyridine ligand in the exo‐6‐position. The cluster has close geometric similarities to the thiaborane and carbaborane analogues. 相似文献
96.
Xiaoming Liu Colin A. Kilner Mark Thornton‐Pett Malcolm A. Halcrow 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(9):1142-1143
The title compound, C17H13N3, is a versatile precursor for polymeric terpyridine derivatives and their metal complexes. The molecule has transoid and near‐coplanar pyridine rings. However, the vinyl group is forced out of the plane of the terpyridyl moiety by a close H?H contact. 相似文献
97.
Luke C. Henderson Megan T. Thornton Nolene Byrne Bronwyn L. Fox Kelsey D. Waugh Jennifer S. Squire Linden Servinis Joshua P. Delaney Hannah L. Brozinski Luke M. Andrighetto Jarrad M. Altimari 《Comptes Rendus Chimie》2013,16(7):634-639
The acid catalysed formation of diphenylmethyl (DPM) thioethers was successfully achieved using the protic ionic liquid (pIL) triethylamine:methanesulfonic acid (TeaMs) as the reaction solvent under microwave irradiation. A slight excess of methanesulfonic acid (10% v/v) was required to facilitate the reaction, which was applied to a variety of thiols. Aliphatic, aromatic and heterocyclic aromatic thiols were converted to their corresponding DPM thioethers in high yields (63–99%), in short reaction times (5–20 min) and using mild temperatures (80–100 °C). Finally, the pIL (TeaMS) was recycled five times without loss of yield. 相似文献
98.
Morisaka T Karczmarski L Akamatsu T Sakai M Dawson S Thornton M 《The Journal of the Acoustical Society of America》2011,129(1):449-457
Field recordings of echolocation signals produced by Heaviside's dolphins (Cephalorhynchus heavisidii) were made off the coast of South Africa using a hydrophone array system. The system consisted of three hydrophones and an A-tag (miniature stereo acoustic data-logger). The mean centroid frequency was 125 kHz, with a -3 dB bandwidth of 15 kHz and -10 dB duration of 74 μs. The mean back-calculated apparent source level was 173 dB re 1 μPa(p.-p.). These characteristics are very similar to those found in other Cephalorhynchus species, and such narrow-band high-frequency echolocation clicks appear to be a defining characteristic of the Cephalorhynchus genus. Click bursts with very short inter-click intervals (up to 2 ms) were also recorded, which produced the "cry" sound reported in other Cephalorhynchus species. Since inter-click intervals correlated positively to click duration and negatively to bandwidth, Heaviside's dolphins may adjust their click duration and bandwidth based on detection range. The bimodal distribution of the peak frequency and stable bimodal peaks in spectra of individual click suggest a slight asymmetry in the click production mechanism. 相似文献
99.
Douglas E. Thornton 《Optics Communications》2011,284(12):2890-2894
The saturation absorption technique is applied to the 87Rb 2S1/2 F″ = 2 → 2P3/2 F′ = 1, 2 and 3 transitions to study the effect of velocity changing collisions (VCC). The VCC caused Doppler pedestal increases with argon pressure from 0 to 110 mTorr and decreases with modulation frequencies of 700-3200 Hz. The resonances of the velocity selective, saturated optical pumping are washed out for pressure of 110 mTorr. The magnitude of the Doppler pedestal relative to the homogeneous features, yields a rate for velocity changing collisions of 6.5 ± 0.2 × 10−10 cm3 s−1. 相似文献
100.