Search results for "harmonic"

Benchmark Thermochemistry of the Hydroperoxyl Radical

2004

A theoretical estimation of the enthalpy of formation for the hydroperoxyl radical is presented. These results are based on CCSD(T)/aug-cc-pCV5Z calculations extrapolated to the basis-set limit with additional corrections. Anharmonic vibrational zero-point energies, scalar relativistic, spin -orbit coupling, and diagonal BornOppenheimer corrections are further used to correct the extrapolated term energies, as well as various empirical corrections that account for correlation effects not treated at the CCSD(T) level. We estimate that ¢fH° ) 3.66 ( 0.10 kcal mol -1 (¢fH° ) 2.96 ( 0.10 kcal mol -1 ) using several reaction schemes. Significantly, it appears to be necessary to include effects o…

Analytic results for virtual QCD corrections to Higgs production and decay

2006

We consider the production of a Higgs boson via gluon-fusion and its decay into two photons. We compute the NLO virtual QCD corrections to these processes in a general framework in which the coupling of the Higgs boson to the external particles is mediated by a colored fermion and a colored scalar. We present compact analytic results for these two-loop corrections that are expressed in terms of Harmonic Polylogarithms. The expansion of these corrections in the low and high Higgs mass regimes, as well as the expression of the new Master Integrals which appear in the reduction of the two-loop amplitudes, are also provided. For the fermionic contribution, we provide an independent check of the…

ChemInform Abstract: Electron Crystallography and Organic Materials with Non-Linear Optical Properties

2010

Results of electron microscopic studies of crystal structures of a number of bis-benzylidene cyclohexanones are presented. It is shown that some of these compounds are efficient crystalline non-linear optically active (NLO) chromophores with second harmonic generation (SHG) properties. Appropriately functionalized chromophores of this type can be used as a polycondensation comonomer to produce partly crystalline main-chain NLO-active polymers. Electron diffraction crystal structural data, obtained for very small crystals, allowed us to get reasonable estimations of macroscopic crystal NLO-coefficients, relating quantum-chemically calculated molecular first hyperpolarizability components to …

Quadratic Nonlinear Behaviour of Various Langmuir-Blodgett Molecules

1989

The Langmuir-Blodgett (L-B) technique is well known as a method of building-up ordered arrays of organic molecules, and especially as a means of imposing a noncentrosymmetric structure from molecules that crystallize in a centrosymmetric space group(1–3). L-B films for use in quadratic nonlinear optics can be ordered in a statistically noncentrosymmetric lattice. The method involves the compression of a mono-layer of the organic molecule, spread on top of a water surface, into a two-dimensional solid, followed by the repeated dipping of the substrate to be coated into and out of the subphase. Monolayers may be deposited onto the substrate both on immersion and withdrawal, resulting in a cen…

Second harmonic generation in ferroelectric liquid crystalline thiadiazole derivatives

1995

Fast vibrational configuration interaction using generalized curvilinear coordinates and self-consistent basis

2010

In this paper, we couple a numerical kinetic-energy operator approach to the direct-vibrational self-consistent field (VSCF)/vibrational configuration interaction (VCI) method for the calculation of vibrational anharmonic frequencies. By combining this with fast-VSCF, an efficient direct evaluation of the ab initio potential-energy surface (PES), we introduce a general formalism for the computation of vibrational bound states of molecular systems exhibiting large-amplitude motion such as methyl-group torsion. We validate our approach on an analytical two-dimensional model and apply it to the methanol molecule. We show that curvilinear coordinates lead to a significant improvement in the VSC…

Limits of Sobolev homeomorphisms

2017

Let X; Y subset of R-2 be topologically equivalent bounded Lipschitz domains. We prove that weak and strong limits of homeomorphisms h: X (onto)-> Y in the Sobolev space W-1,W-p (X, R-2), p >= 2; are the same. As an application, we establish the existence of 2D-traction free minimal deformations for fairly general energy integrals. Peer reviewed

Mutes harmoniku tīmekļa vietne

2019

Kvalifikācijas darba mērķis ir izstrādāt tīmekļa vietni “AllAboutHarmonica” uzziņai par mutes harmoniku spēlēšanu. Šīs tīmekļa vietnes uzdevumi ir iepazīstināt lietotājus ar mutes harmoniku spēlēšanas pamatiem, rast lietotājam vēlmi spēlēt mutes harmonikas un piedāvāt lietotājam iespēju pieteikties uz privātstundām. Šī tīmekļa vietne sastāv no informatīvā materiāla par mutes harmonikām, to spēlēšanu, dziesmām un kontaktinformācijas formu kurā lietotājs atstāj savu informāciju lai ar viņu sazinātos par iespējamajām privātstundām. Tīmekļa vietnei “AllAboutHarmonica” ir 3 galvenās funkcijas – vietnes satura apskate, satura papildināšana, rediģēšana un dzēšana no administratora puses, kā arī in…

Femtosecond coherent anti-Stokes Raman-scattering polarization beat spectroscopy of I2–Xe complex in solid krypton

2006

Time-resolved coherent anti-Stokes Raman-scattering (CARS) measurements are carried out to study the interaction between xenon atom and iodine molecule in a solid krypton matrix. Interference between the CARS polarizations of the "free" and complexed iodine molecules is observed, while the quantum beats of the complex are not detected due to low concentration. Vibrational analysis based on the polarization beats yields accurate molecular constants for the I2-Xe complex. The harmonic frequency of the I2-Xe complex is found to be redshifted by 0.90 cm-1 when compared to the free I2, whereas the anharmonicity is approximately the same. The dephasing rate of the complex is found to be somewhat …

A single-point strategy based on IEEE 1459-2000 for the Detection of Dominant Harmonic Sources in Power Systems

2008

This paper deals with a novel single-point strategy for the detection of harmonic sources in power systems. It is an enhancement of a previous strategy, developed by authors, which is based on the IEEE Std. 1459-2000 approach. In the paper, the effectiveness of the strategy is investigated, by means of simulation tests, which were carried out on a IEEE standard three-phase test power system. The analysis is carried out by considering also the presence of the measurement transducers.