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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Il nuovo cimento della Società Italiana di Fisica 4 (1984), S. 529-547 
    ISSN: 0392-6737
    Keywords: Inelastic seattering of atoms and molecules
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Description / Table of Contents: Riassunto Una superficie di potenziale recentemente ottenuta da noi per il sistema He−N2 è utilizzata per studiare il processo quantico di transferimento d'energia interna, per via collisionale, fra i numerosi livelli rotazionali della molecola bersaglio ed alcuni dei livelli vibrazionali che risultano energeticamente accessibili alle velocità traslazionali qui esaminate. La natura anisotropa dell'accoppiamento (V, T) è così analizzata dal punto di vista del suo effettodiretto su osservabili dinamiche come sezioni d'urto inelastiche, parziali integrali e differenziali. Le strutture interferenziali che si originano in tale sistema sono scarsamente influenzate dalla presenza o meno di accoppiamento vibrazionale e sono qui discusse in relazione alla loro diversità con altri sistemi polari (LH, KF) precedentemente da noi studiati con tecniche teoriche simili.
    Abstract: Резюме Недавно полученное анизотропное взаимодействие для He−N2 систем испоиьзуется в зтой работе для поробного анализа квантового переноса внутренней знергии меЗду многочисленными ротационными состояниями молекул мишени и несколькими колебатэльными состояниями. Анализируется природа анизотропии вращательіх и колебательньіх связей с точки зрения влияния зтой анизотропии на динамичэскиэ наблюдаемье величины, такиэ как интэграиьіе и дифференциалъные неупругие поперечные сеч∈ния. Интерферендионные структуры, которы∈ возникют в таких системах, слабо зависят от вибрадионной связх. Проводится сравнениэ полученных резульіх резулвтатоб с резулвтатми для других полярных молекул, ранее рассмотренных в рамках того Зе теоретическочо подхода.
    Notes: Summary A newly obtained anisotropic interaction for the He−N2 system is here employed to analyse in detail the inelastic flux distribution between the many rotational states of the target molecule and the few of its vibrational states that are accessible at near-thermal ranges of collisional energy. Both integral and differential inelastic cross-sections are obtained from a quantal formulation of the energy transfer process, within which the orientational dependence of rotational and vibrational couplings is examined for its bearing on the interference structures that are exhibited by the dynamical observables as functions of final rotational states and of centre-of-mass scattering angles. Similarities and differences with previously studied polar molecules also interacting with helium are underlined and explained.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Il nuovo cimento della Società Italiana di Fisica 3 (1984), S. 561-577 
    ISSN: 0392-6737
    Keywords: Inelastic scattering of atoms and molecules ; Lasing processes ; Chemical kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Description / Table of Contents: Riassunto Il problema dell'eccitazione rotovibrazionale di molecole di HF in collisione con atomi di He è stato trattato all'interno di un modello quantomeccanico del processo dinamico e con l'uso di una forma accurata di funzione potenziale. Il numero estremamente grande di equazioni che si originano dal corretto accoppiamento fra i possibili canali dinamici è stato ridotto attraverso l'uso dell'approssimazione impulsiva per i moti rotazionali pur trattando rigorosamente le vibrazioni. Il comportamento delle sezioni d'urto parziali anelastiche, integrali e differenziali, rotazionali e vibrorotazionali è studiato in dettaglio con lo studio di caratteristiche regioni del potenziale d'interazione. Si riscontra nel presente sistema un sostanziale disaccoppiamento fra moti rotazionali e vibrazionali, nonché una generale inefficienza del processo di trasferimento energetico.
    Abstract: Резюме В рамках квантовой механики рассматривается проблема одновременных колебательных и вращательных возбуждений молекул HF при соударениях с атомами гелия. При рассмотрении используется точная форма потенциальной энергии, предложенная ранее в литературе. Сложная связь вращательных и колебательных каналов частично упрощается за счет учета различных временных масштабов этих каналов, что позволяет уменьшить число соответстветвующих связанных уравнений для многоканального рассеяния. Проводится сравнение интегральных и дифференциальных, колебательных и вращательных парциальных поперечных неупругих сечений в зависимости от особенностей потенциала взаимодействия. Для рассматриваемой системы отмечается существенная неэффективность процессов (R, T) применительно к процессам (V, T) или (V, R, T).
    Notes: Summary The problem of simultaneous vibrational and rotational excitations of HF molecules in collision with helium has been approached via a quantum-mechanical treatment of the full dynamics and by employing a very accurate potential-energy surface suggested earlier in the literature. The complicated coupling of rotational and vibrational channels has been partly simplified by taking advantage of their different time scales, thus allowing a reduction of dimensionality for the corresponding multichannel scattering couple equations (IOS approximation). The relative influence of the various modes on preferential energy depositions upon collision is discussedvis à vis specific features of the interaction and specific regions of the range of collision energies employed. The essential inefficiency of (R, T) processes as apposed to (V, T) or (V, R, T) processes is once more pointed out for the present system.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Il nuovo cimento della Società Italiana di Fisica 2 (1983), S. 731-750 
    ISSN: 0392-6737
    Keywords: Inelastic scattering of atoms and molecules
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Description / Table of Contents: Riassunto Si presenta un modello quantistico di tipo generale per trattare il rilassamento vibrazionale di molecole poliatomiche in regime collisionale e se ne esaminano le applicazioni al caso di CO2 interagente con atomi di elio. Una semplificazione notevole delle equazioni diffusionali necessarie per trattare correttamente il necessario sviluppo sull’esteso numero di stati molecolari che partecipano al processo è raggiunta considerando ciascun modo normale di vibrazione in maniera indipendente ed accoppiando quindi ciascun sottoinsieme di stati attraverso uno sviluppo, analitico del potenziale molecolare corretto intorno al punto classico di massimo avvicinamento delle traiettorie. Quanto è tralasciato e trattato in maniera semplificata nel presente modello è discusso per il caso dell’interazione CO2-He e per confrontare il diverso comportamento die vari rilassamenti dei suoi specifici modi vibrazionali. Si mostra come la presente trattazione interpreti in modo corretto i processi competitivi presenti in tempi di rilassamento misurati a basse temperature nelle miscele CO2/He e promette di poter trattare in modo qualitativamente realistico e rapido dal punto di vista dei tempi di calcolo sistemi ad elevati gradi di libertà interni.
    Notes: Summary A general quantum model for treating vibrational relaxation in polyatomic molecules is presented and its application to CO2 relaxation in collision with helium is discussed. A drastic simplification of the large expansion over molecular states, which is usually needed for complex targets, is here achieved by treating each normal mode independently and by then coupling each manifold of levels via the intermolecular potential through an analytic expansion of the latter that yields simple expressions for the coupling matrix elements. The effects of the physical factors which are here disregarded and/or simplified by the model are discussed and qualitatively assessed by comparison with previous calculations on the same system.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Il nuovo cimento della Società Italiana di Fisica 6 (1985), S. 75-92 
    ISSN: 0392-6737
    Keywords: Inelastic scattering of atoms and molecules
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Description / Table of Contents: Riassunto L’origine fisica delle forze che controllano il trasferimento collisionale di energia interna molecolare è stata da noi studiata in dettaglio per sistemi debolmente interagenti e formanti molecole di Van der Waals. Nel presente lavoro si esamina invece un sistema in cui forti interazioni esistono fra lo ione incidente e la molecola bersaglio e si studia il comportamento delle corrispondenti sezioni d’urto, parziali e totali, per eccitazioni rotovibrazionali in collisioni H±CO (1 ∑). L’esistenza di elevate probabilità per cattura risonante nei numerosi stati legati del sistema in esame può essere direttamente rilevata, in funzione dell’energia di collisione, attraverso l’effetto che tali risonanze hanno sulla distribuzione di flusso nei vari canali inelastici. La loro dipendenza dalle caratteristiche generali della superficie di potenziale coinvolta è esaminata e discussa.
    Abstract: Резюме Для слабо взаимодействующих систем и образующих молекулярные связи за счет взаимодействия Ван дер Ваальса были подробно исследованы физические силы, которые обусловливают столкновительный перенос внутренней молекулярной энергии. В этой статье аналогичный анализ проводится для сильных взаимодействий, существующих в ион-молекулярных соударениях. Для случая протон-СО вычисляются частные, интегральные и дифференциальные ротационноколебательные неупругие поперечные сечения. Существующая больщая вероятность резонансного захвата вызывает заметные флуктуации с энергией в распределении потока между различными неупругими каналами. Исследуется и обсуждается зависимость распределения потока от общих характеристик поверхности рассматриваемого потенциала.
    Notes: Summary The detailed physical forces that preside over the collisional transfer of molecular internal energy have already been extensively analysed by us for weakly interacting systems that form only Van der Waals (VdW) bonds. In the present paper a similar analysis is carried out for the strong interaction existing in ion-molecule collisions and the partial, integral and differential, rotovibrationally inelastic cross-sections are computed for the proton-CO case. The existing large probability of resonant trapping (shape and Feshbach resonances) causes marked fluctuations with collision energy in the relative flux distribution between outgoing channels and leads to very different patterns of energy partitioning and redistribution after the collisional events. The differences are here related in detail to the collisional coupling generated by the lowest adiabatic potential-energy surface (PES) of the present system.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Inorganica Chimica Acta 40 (1980), S. X169-X170 
    ISSN: 0020-1693
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Chemical Physics Letters 147 (1988), S. 126-132 
    ISSN: 0009-2614
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Chemical Physics Letters 212 (1993), S. 512-517 
    ISSN: 0009-2614
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Chemical Physics Letters 158 (1989), S. 250-256 
    ISSN: 0009-2614
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 92 (1988), S. 925-931 
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Electrochimica Acta 24 (1979), S. 209-212 
    ISSN: 0013-4686
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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