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21.
On the basis of the absorption coefficient calculation it is shown that strong optical and mechanical anharmonicity of the OH group vibrations and the interaction between the main tone and the overtone of the other vibration of the same OH group and the same symmetry (Fermi-resonance) leads to the formation of two-phonon bound states (biphonons) seen in spectra as “additional” sharp bands. The IR and Raman bands half-width and shape of the main tone and the bound state is measured as a function of temperature and a possible theoretical treatment is proposed. The anharmonicity parameters and low-frequency vibrations responsible for the temperature behavour of the main tone and the biphonons are determined. 相似文献
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Özge Pala Dirk J Vriens Jac AM Vennix 《The Journal of the Operational Research Society》2015,66(4):593-601
Escalation of commitment, the tendency of decision makers to keep on investing in losing courses of action, has been shown to be a costly decision bias that affects many areas of decision making. Even though escalation is a widely studied phenomenon, there has been comparatively little research on how to avoid this bias. The present study focuses on de-escalation of commitment and proposes that causal loop diagrams (CLDs) can help to decrease escalating commitment to a failing course of action. By means of an experiment, this study shows that using a CLD decreases escalation tendencies. 相似文献
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García Ruano JL Gamboa AE Gutiérrez LG Martín Castro AM Rodríguez Ramos JH Yuste F 《Organic letters》2000,2(6):733-736
A new kind of chiral dienophiles, cyclic vinyl-p-tolylsulfilimines (2a and 2b), were obtained from the corresponding (Z)-sulfinylacrylonitriles with HBF(4) and methanol. The asymmetric Diels-Alder reaction of optically pure 2a with cyclopentadiene under mild thermal or catalyzed conditions afforded only the endo-4a adduct with complete endo and pi-facial selectivities. The ability of the sulfilimine moiety to enhance the dienophilic reactivity of the double bond is similar to that of the sulfinyl group. 相似文献
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N.A. Atamas A.M. Yaremko T. Seeger A. Leipertz A. Bienko Z. Latajka H. Ratajczak A.J. Barnes 《Journal of Molecular Structure》2004,708(1-3):189-195
The experimental and theoretically predicted Raman spectra for the first few alkanes in the homologous series: methane, ethane, propane and butane are presented for the region 2700–3100 cm−1. The structure of the spectra is rather complex. Analysis of the results obtained shows that Fermi resonance occurs between the CH stretching vibrations in the 3000 cm−1 region and the 2ν overtones of deformation vibrations in the low frequency (1450–1500 cm−1) region. 相似文献
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Toledano P Figueiredo Neto AM de Sant'Ana ZA 《Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics》2000,61(1):486-492
Experimental investigations of lyotropic cholesterics fluids are presented which show that changes in the shape anisotropy and chirality of the micellar population determine the topology of the temperature-concentration phase diagrams. For given amounts of the substances which induce the chirality and modify the shape anisotropy of the micelles, two distinct biaxial cholesteric phases are disclosed in the phase diagrams. This is interpreted in the framework of the catastrophe theory of phase transitions. 相似文献