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Vectors, importation

The rotational correlation time can be directly obtained from 13C or deuterium relaxation measurements on a diamagnetic analogue (Y(III), La(III) or Lu(III)) of the Gd(III) complex [38,70-72]. One disadvantage is low sensitivity of 13C or 2D at natural abundance. Moreover, these methods do not measure the rotation of the metal - coordinated water vector, important from the practical point of view, and this may cause problems mainly in the case of large molecules. [Pg.80]

Figure 7a displays a SFM phase image of a spin-coated S47H10M4382 film that has a disordered surface structure. The ordering effect of the simultaneous solvent vapor annealing and application of a voltage between the electrodes is shown in Fig. 7b. After 6.5 h of treatment the stripe pattern appears highly ordered parallel to the electric field vector. Importantly, during the swelling of the film, the polar middle PHEMA block remains anchored to the substrate. This preserves the self-assembled stripe pattern of the two major PS and PMMA blocks (Fig. 7c). Figure 7a displays a SFM phase image of a spin-coated S47H10M4382 film that has a disordered surface structure. The ordering effect of the simultaneous solvent vapor annealing and application of a voltage between the electrodes is shown in Fig. 7b. After 6.5 h of treatment the stripe pattern appears highly ordered parallel to the electric field vector. Importantly, during the swelling of the film, the polar middle PHEMA block remains anchored to the substrate. This preserves the self-assembled stripe pattern of the two major PS and PMMA blocks (Fig. 7c).
Since there are N energy groups and n regions in the system, we may express the equations more succinctly in a matrix and vector form with vector density Af and vector importance, each having nfVcomponents. The equations would then take the form... [Pg.321]

In conclusion, through extensive basic investigation of adenoviral vectors, important biology has been learned that will allow a more rational utilization of this technology for therapeutic applications. [Pg.44]

The choice of the vector d is very important for the exploitation of cooccurrence matrix. For segmentation operation, d will be calculated with the result that could separate the noise of defects. We will have therefore to research transitions to frontiers, that is to say couples (i, j) such that i is an intensity linked to the noise and j an intensity linked to the defect. [Pg.234]

Let u be a vector valued stochastic variable with dimension D x 1 and with covariance matrix Ru of size D x D. The key idea is to linearly transform all observation vectors, u , to new variables, z = W Uy, and then solve the optimization problem (1) where we replace u, by z . We choose the transformation so that the covariance matrix of z is diagonal and (more importantly) none if its eigenvalues are too close to zero. (Loosely speaking, the eigenvalues close to zero are those that are responsible for the large variance of the OLS-solution). In order to liiid the desired transformation, a singular value decomposition of /f is performed yielding... [Pg.888]

If the scalar order parameter of the Ising model is replaced by a two-component vector n = 2), the XY model results. All important example that satisfies this model is the 3-transition in helium, from superfiuid helium-II... [Pg.656]

There are other important properties tliat can be measured from microwave and radiofrequency spectra of complexes. In particular, tire dipole moments and nuclear quadmpole coupling constants of complexes may contain useful infonnation on tire stmcture or potential energy surface. This is most easily seen in tire case of tire dipole moment. The dipole moment of tire complex is a vector, which may have components along all tire principal inertial axes. [Pg.2442]

Measurements of Stark splittings in microwave and radiofrequency spectra allow tliese components to be detennined. The main contribution to tire dipole moment of tire complex arises from tire pennanent dipole moment vectors of tire monomers, which project along tire axes of tire complex according to simple trigonometry (cosines). Thus, measurements of tire dipole moment convey infonnation about tire orientation of tire monomers in tire complex. It is of course necessary to take account of effects due to induced dipole moments and to consider whetlier tire effects of vibrational averaging are important. [Pg.2442]

Light scattering teclmiques play an important role in polymer characterization. In very dilute solution, where tire polymer chains are isolated from one anotlier, tire inverse of tire scattering function S (q) can be expressed in tire limit of vanishing scattering vector > 0 as 1121... [Pg.2518]

In the presence of a phase factor, the momentum operator (P), which is expressed in hyperspherical coordinates, should be replaced [53,54] by (P — h. /r ) where VB creates the vector potential in order to define the effective Hamiltonian (see Appendix C). It is important to note that the angle entering the vector potential is shictly only identical to the hyperangle <]> for an A3 system. [Pg.53]

The relative shift of the peak position of the rotational distiibution in the presence of a vector potential thus confirms the effect of the geometric phase for the D + H2 system displaying conical intersections. The most important aspect of our calculation is that we can also see this effect by using classical mechanics and, with respect to the quantum mechanical calculation, the computer time is almost negligible in our calculation. This observation is important for heavier systems, where the quantum calculations ai e even more troublesome and where the use of classical mechanics is also more justified. [Pg.58]

The ordinary BO approximate equations failed to predict the proper symmetry allowed transitions in the quasi-JT model whereas the extended BO equation either by including a vector potential in the system Hamiltonian or by multiplying a phase factor onto the basis set can reproduce the so-called exact results obtained by the two-surface diabatic calculation. Thus, the calculated hansition probabilities in the quasi-JT model using the extended BO equations clearly demonshate the GP effect. The multiplication of a phase factor with the adiabatic nuclear wave function is an approximate treatment when the position of the conical intersection does not coincide with the origin of the coordinate axis, as shown by the results of [60]. Moreover, even if the total energy of the system is far below the conical intersection point, transition probabilities in the JT model clearly indicate the importance of the extended BO equation and its necessity. [Pg.80]

State basis in the molecule consists of more than one component. This situation also characterizes the conical intersections between potential surfaces, as already mentioned. In Section V, we show how an important theorem, originally due to Baer [72], and subsequently used in several equivalent forms, gives some new insight to the nature and source of these YM fields in a molecular (and perhaps also in a particle field) context. What the above theorem shows is that it is the truncation of the BO set that leads to the YM fields, whereas for a complete BO set the field is inoperative for molecular vector potentials. [Pg.101]

The important outcome from this transformation is that now the non-adiabatic coupling term t is incorporated in the Schrodinger equation in the same way as a vector potential due to an external magnetic field. In other words, X behaves like a vector potential and therefore is expected to fulfill an equation of the kind [111a]... [Pg.689]

The quantum mechanical importance of a vector potential A, in regions where the magnetic field is zero, was first recognized by Aharonov and Bohm in their seminal 1959 paper [112]. [Pg.690]

In this series of results, we encounter a somewhat unexpected result, namely, when the circle surrounds two conical intersections the value of the line integral is zero. This does not contradict any statements made regarding the general theory (which asserts that in such a case the value of the line integral is either a multiple of 2tu or zero) but it is still somewhat unexpected, because it implies that the two conical intersections behave like vectors and that they arrange themselves in such a way as to reduce the effect of the non-adiabatic coupling terms. This result has important consequences regarding the cases where a pair of electronic states are coupled by more than one conical intersection. [Pg.706]

Molecules are usually represented as 2D formulas or 3D molecular models. WhOe the 3D coordinates of atoms in a molecule are sufficient to describe the spatial arrangement of atoms, they exhibit two major disadvantages as molecular descriptors they depend on the size of a molecule and they do not describe additional properties (e.g., atomic properties). The first feature is most important for computational analysis of data. Even a simple statistical function, e.g., a correlation, requires the information to be represented in equally sized vectors of a fixed dimension. The solution to this problem is a mathematical transformation of the Cartesian coordinates of a molecule into a vector of fixed length. The second point can... [Pg.515]

Ac Che limic of Knudsen screaming Che flux relacions (5.25) determine Che fluxes explicitly in terms of partial pressure gradients, but the general flux relacions (5.4) are implicic in Che fluxes and cheir solution does not have an algebraically simple explicit form for an arbitrary number of components. It is therefore important to identify the few cases in which reasonably compact explicit solutions can be obtained. For a binary mixture, simultaneous solution of the two flux equations (5.4) is straightforward, and the result is important because most experimental work on flow and diffusion in porous media has been confined to pure substances or binary mixtures. The flux vectors are found to be given by... [Pg.42]

I be second important practical consideration when calculating the band structure of a malericil is that, in principle, the calculation needs to be performed for all k vectors in the Brillouin zone. This would seem to suggest that for a macroscopic solid an infinite number of ectors k would be needed to generate the band structure. However, in practice a discrete saaipling over the BriUouin zone is used. This is possible because the wavefunctions at points... [Pg.175]

Iditional importance is that the vibrational modes are dependent upon the reciprocal e vector k. As with calculations of the electronic structure of periodic lattices these cal-ions are usually performed by selecting a suitable set of points from within the Brillouin. For periodic solids it is necessary to take this periodicity into account the effect on the id-derivative matrix is that each element x] needs to be multiplied by the phase factor k-r y). A phonon dispersion curve indicates how the phonon frequencies vary over tlie luin zone, an example being shown in Figure 5.37. The phonon density of states is ariation in the number of frequencies as a function of frequency. A purely transverse ition is one where the displacement of the atoms is perpendicular to the direction of on of the wave in a pmely longitudinal vibration tlie atomic displacements are in the ition of the wave motion. Such motions can be observed in simple systems (e.g. those contain just one or two atoms per unit cell) but for general three-dimensional lattices of the vibrations are a mixture of transverse and longitudinal motions, the exceptions... [Pg.312]

Field variables identified by their magnitude and two associated directions are called second-order tensors (by analogy a scalar is said to be a zero-order tensor and a vector is a first-order tensor). An important example of a second-order tensor is the physical function stress which is a surface force identified by magnitude, direction and orientation of the surface upon which it is acting. Using a mathematical approach a second-order Cartesian tensor is defined as an entity having nine components T/j, i, j = 1, 2, 3, in the Cartesian coordinate system of ol23 which on rotation of the system to ol 2 3 become... [Pg.258]

The result of all of the vibrational modes contributions to la (3 J-/3Ra) is a vector p-trans that is termed the vibrational "transition dipole" moment. This is a vector with components along, in principle, all three of the internal axes of the molecule. For each particular vibrational transition (i.e., each particular X and Xf) its orientation in space depends only on the orientation of the molecule it is thus said to be locked to the molecule s coordinate frame. As such, its orientation relative to the lab-fixed coordinates (which is needed to effect a derivation of rotational selection rules as was done earlier in this Chapter) can be described much as was done above for the vibrationally averaged dipole moment that arises in purely rotational transitions. There are, however, important differences in detail. In particular. [Pg.404]

The idea of a linear combination is an important idea that will be encountered when we discuss how a matrix operator affects a linear combination of vectors. [Pg.522]

The value of insecticides in controlling human and animal diseases spread by insects has been dramatic. It has been shown that between 1942 and 1952, the use of DDT in pubHc health measures to control the mosquito vectors of malaria and the human body louse vector of typhus saved five million hves and prevented 100 million illnesses (4). Insecticides have provided the means to control such important human diseases as filariasis transmitted by Culex mosquitoes and onchocerciasis transmitted by Simulium blackflies. [Pg.268]


See other pages where Vectors, importation is mentioned: [Pg.155]    [Pg.73]    [Pg.652]    [Pg.972]    [Pg.1059]    [Pg.1369]    [Pg.1373]    [Pg.2365]    [Pg.2473]    [Pg.42]    [Pg.59]    [Pg.63]    [Pg.105]    [Pg.188]    [Pg.406]    [Pg.516]    [Pg.128]    [Pg.43]    [Pg.31]    [Pg.171]    [Pg.267]    [Pg.268]    [Pg.300]   
See also in sourсe #XX -- [ Pg.330 ]




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