Car method

The coherent fs time-resolved CARS method is highly sensitive for the investigation of collision induced (or pressure dependent) changes in optical line shapes especially when line mixing occurs and frequency resolved measurements come to their limits [7]. The fs-CARS spectroscopy is applied to various collision systems (N2-N2, N2-rare gas, C2H2-C2H2, CO-CO)... 

The conventional narrowband CARS process probes one particular vibrational mode selectively. Conversely, so-called broadband CARS measurements, using ultrashort pulsed laser sources, can probe multiple RS-active vibrational modes simultaneously [19, 29-31]. In the case of two-beam broadband CARS method, one of the two beams has a narrow bandwidth and the other a broad bandwidth. Therefore, the technical issue is how to generate these beams from a single laser source. Typically, subpicosecond pulses from a conventional solid-state femtosecond laser... 

Conventional CARS spectroscopy is carried out using the two-color CARS process induced by continuous-wave or narrowband pulsed laser sources. On the basis of the progress in the broadband pulsed laser technology, broadband CARS methods are now drawing much attention [29-31]. One of most remarkable examples is... 

Continuous-addition-of-reagent methods In continu-ous-addition-of-reagent (CAR) methods, a reagent is added at a constant rate to the species of interest and the kinetic graph (absorbance or fluorescence as a function of time) is recorded simultaneously with the aid of an automatic, computer-controlled system. A CAR system typically consists of (1) an addition unit composed of an autoburette, a fan stirrer, and a ther-mostatted vessel as reaction cell, (2) a photometric... 

Carbonate as Ba source. Minimum carbonate content (CAR Method) Kruger et al. (1994, 1997), Kaldis et al. (1997a,b)... 

Solid-state reaction with CuO and YjOj in flowing oxygen Further like CAR method... 

To simulate the conditions in a car, methods for the determination of the lightfastness at elevated temperatures of, for example 83°C, have been defined by the automotive industry. Standard methods are the FAKRA test (DIN 75202), SAE J-1885 and DIN 75202. 

Describe the CARS method and its application to combustion diagnostics. 

However, it should be noted that most of the EEG studies on physical fatigue is based on the referential EEG data. It has been pointed out by [6] that the referential method may have certain drawbacks since it is dependent on the location of the reference. Thus, it has been suggested using both the Common Average Reference (CAR) method as well as the Current Source Density (CSD) method [7] hand in hand to provide a more complete view of the EEG content. 

In this study, only the eyes closed data will be process. This is because the eyes-closed condition exists immediately after the experimental task has been completed. The EEG recordings obtained at each location is actually dependent on the reference electrode. Montages have been used to remove this reference electrode effect. The Referential (REF) method is compared with both the Common Average Reference (CAR) method as well as the Current Source Density (CSD) method. In order to compute the CSD, the software is downloaded based on the algorithm given by [7]. The formula to calculate the CAR is given by (4)... 

The changes in the 5 frequency range are not significant and thus not shown here. Based on Fig. 4, it can be seen that the REF method and the CAR method indicate increase of 7 Hz 9 rhythm at the parietal and occipital region. Using the CSD method indicated increase in the 0 rhythm at the left and right temporal region. 

Local analysis can be carried out only by the LIF and CARS methods. They have the highest time resolution. The CARS method or any other method of Raman spectroscopy are imiversal but have low sensitivity. Therefore, it is reasonable to use resonance Raman spectroscopy because its sensitivity is higher. Due to a low sensitivity, Raman spectroscopy is combined with a pulse source of generation of active... 

Specific solute-solvent interactions involving the first solvation shell only can be treated in detail by discrete solvent models. The various approaches like point charge models, siipennoleciilar calculations, quantum theories of reactions in solution, and their implementations in Monte Carlo methods and molecular dynamics simulations like the Car-Parrinello method are discussed elsewhere in this encyclopedia. Here only some points will be briefly mentioned that seem of relevance for later sections. 

Figure B2.3.8. Energy-level sehemes deseribing various optieal methods for state-seleetively deteeting ehemieal reaetion produets left-hand side, laser-indueed fluoreseenee (LIF) eentre, resonanee-enlianeed multiphoton ionization (REMPI) and right-hand side, eoherent anti-Stokes Raman speetroseopy (CARS). The ionization oontinuiim is denoted by a shaded area. The dashed lines indieate virtual eleetronie states. Straight arrows indieate eoherent radiation, while a wavy arrow denotes spontaneous emission.

While simulations reach into larger time spans, the inaccuracies of force fields become more apparent on the one hand properties based on free energies, which were never used for parametrization, are computed more accurately and discrepancies show up on the other hand longer simulations, particularly of proteins, show more subtle discrepancies that only appear after nanoseconds. Thus force fields are under constant revision as far as their parameters are concerned, and this process will continue. Unfortunately the form of the potentials is hardly considered and the refinement leads to an increasing number of distinct atom types with a proliferating number of parameters and a severe detoriation of transferability. The increased use of quantum mechanics to derive potentials will not really improve this situation ab initio quantum mechanics is not reliable enough on the level of kT, and on-the-fly use of quantum methods to derive forces, as in the Car-Parrinello method, is not likely to be applicable to very large systems in the foreseeable future. 

Abstract. We present novel time integration schemes for Newtonian dynamics whose fastest oscillations are nearly harmonic, for constrained Newtonian dynamics including the Car-Parrinello equations of ab initio molecular dynamics, and for mixed quantum-classical molecular dynamics. The methods attain favorable properties by using matrix-function vector products which are computed via Lanczos method. This permits to take longer time steps than in standard integrators. 

In the Car-Parrinello method [6] (and see, e.g., [24, 25, 16, 4]), the adiabatic time-dependent Born-Oppenheimer model is approximated by a fictitious Newtonian dynamics in which the electrons, represented by a set of... 

F. A. Bornemann and Ch. Schutte. A mathematical investigation of the Car-Parrinello method. Preprint SC 96-19, ZIB Berlin, 1996. To appear in Numer. Math. 

Secondly, the ultimate properties of polymers are of continuous interest. Ultimate properties are the properties of ideal, defect free, structures. So far, for polymer crystals the ultimate elastic modulus and the ultimate tensile strength have not been calculated at an appropriate level. In particular, convergence as a function of basis set size has not been demonstrated, and most calculations have been applied to a single isolated chain rather than a three-dimensional polymer crystal. Using the Car-Parrinello method, we have been able to achieve basis set convergence for the elastic modulus of a three-dimensional infinite polyethylene crystal. These results will also be fliscussed. 

The structure of the metallocene cation energy minimised with the Car-Parrinello method agrees well with the experimentally obtained crystal structures of related complexes. Typical features of the structure as obtained from X-ray diffraction on crystals of very similar neutral complexes (e.g., the dichlorides), such as small differences in distances between C atoms within a cyclopentadienyl (Cp) ring, as well as differences in distances between the C atoms of the Cp ring and the Zr atom, were revealed from the simulations. 

To calculate the partition function for a system of N atoms using this simple Monte Car integration method would involve the following steps ... 

A key feature of the Car-Parrinello proposal was the use of molecular dynamics a simulated annealing to search for the values of the basis set coefficients that minimise I electronic energy. In this sense, their approach provides an alternative to the traditioi matrix diagonalisation methods. In the Car-Parrinello scheme, equations of motion ... 

An alternative to the Car-Parrinello method is the following scheme, which separates the electronic and nuclear motions ... 

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