Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Trivial systems

Enzymes may be named trivially or more formally. Trivial naming tends to predominate in industry and two trivial systems exist ... [Pg.77]

As before, the equivalency of systems a and b is trivial. Systems b and c can be made equivalent by imposing the conditions... [Pg.328]

A polynucleotide chain such as that in Chart 10 would then be indicated in the trivial system as in the following example UpCpTpApGp. This system differentiates simply among the various dinucleotides. UpU is deoxyuridylyl-3, 5 -deoxyuridine, dUpU is de-oxyuridylyl-(3, 5)-deoxyuridine, pUp is uridine-3, 5 -diphosphate. [Pg.291]

For anything but the most trivial systems, it is not possible to solve the electronic Schrodinger equation exactly, and approximate techniques must instead be used. There exist a variety of approximate methods, including Hartree-Fock (HF) theory, single- and multireference correlated ab initio methods, semiempirical methods, and density functional theory. We discuss each of these in turn. In Hartree-Fock theory, the many-electron wavefunction vF(r1, r2,..., r ) is approximated as an antisymmetrized product of one-electron wavefunctions, ifijfi) x Pauli principle. This antisymmetrized product is known as a Slater determinant. [Pg.464]

When the flow regime is not known, the analytical calculation of ut from Equation (12) requires choosing an equation for Cd, such as, for example, Equation (15), and solving a non-trivial system of two nonlinear equations. To avoid the analytical solution, an iterative procedure can be applied by guessing an initial value of CD or Rep ... [Pg.213]

First, the current state of affairs is remarkably similar to that of the field of computational molecular dynamics 40 years ago. While the basic equations are known in principle (as we shall see), the large number of unknown parameters makes realistic simulations essentially impossible. The parameters in molecular dynamics represent the force field to which Newton s equation is applied the parameters in the CME are the rate constants. (Accepted sets of parameters for molecular dynamics are based on many years of continuous development and checking predictions with experimental measurements.) In current applications molecular dynamics is used to identify functional conformational states of macromolecules, i.e., free energy minima, from the entire ensemble of possible molecular structures. Similarly, one of the important goals of analyzing the CME is to identify functional states of areaction network from the entire ensemble of potential concentration states. These functional states are associated with the maxima in the steady state probability distribution function p(n i, no, , hn). In both the cases of molecular dynamics and the CME applied to non-trivial systems it is rarely feasible to enumerate all possible states to choose the most probable. Instead, simulations are used to intelligently and realistically sample the state space. [Pg.264]

A system of fundamental theoretical importance in many-body theory is the uniform-density electron gas. After decades of effort, exchange-correlation effects in this special though certainly not trivial system are by now well understood. In particular, sophisticated Monte Carlo simulations have provided very useful information (5) and have been conveniently parametrized by several authors (6). If the exchange-correlation hole function at a given reference point r in an atomic or molecular system is approximated by the hole function of a uniform electron gas with spin-densities given by the local values of p (r) and Pp(C obtain an... [Pg.168]

From the behavior of this trivial system, we can infer that more complex systems have the following characteristics ... [Pg.280]

The problem is to get a computable expression for the ground state wave function without solving the Schrodinger equation for the many body hamiltonian of (1), obviously an impossible task for any non trivial system. As usual in many body problems, we can resort to the variational principle which states that the energy of any proper trial state ) will be greater or equal to... [Pg.645]

The most important direction for future research is the application of the multiscale systems approach to a broad range of additional non-trivial systems. There are a large number of such candidates, including many in which electrochemical phenomena play a significant role. The greatest number of electrochemical-based applications in the near term is likely to be in micro- and nanoelectronics, given the head-start in applications of multiscale simulation and the intense interest of the semiconductor industry, as cited earlier in this chapter. Additional applications are likely to arise in nanobiomedical sensors and other nanobiological devices, many of which are closely related to micro- and nanoelectronic processes in terms of chemistry, physics, materials and components. The pursuit of specific applications will also serve to improve the systems tools, as any nontrivial applications are apt to do. [Pg.323]

Obviously, the Hamiltonian (7) commutes with any product of Pa which is equal to to the product of azab operators around a set of closed loops, these products are fixed by the constraint. However, for a topologically non-trivial system there appear a number of other integrals of motion for a system with K openings a product of azb operators along contour, 7 that begins at one opening and ends at another (or at the outer boundary, see Fig. 6)... [Pg.187]

Type of Proofs Human-directed Proof - mandraulic, and time-consuming for aU but tbe most trivial system, and also prone to human error. Automated Proof - use of various tool sets to undertake automated proofs. [Pg.308]

An example of a simple but non-trivial system is presented in (Bouissou Dutuit 2004). There, it is modeled in two different ways by a stochastic Petri net and by a Boolean Driven Markov Process (BDMP). In the following, we will present a model of the same system using LARES. [Pg.173]

If nothing crosses the borders, conserved quantities are constant within the system. This conservation principle is translated into mathematics in Eqs. (3.1) and (3.2). This is a closed system. We can model a closed system, which is usually a trivial system, with Eqs. (3.1) and (3.2) ... [Pg.63]

Large amounts of data required. For non-trivial systems, neural networks only function well when they are trained on many examples of each class. The more examples of a class you have, the better the network will learn. Unfortunately, automatic systems are rarely required to recognize the common inputs, but instead tend to be asked to recognize the rare patterns for which examples are scarce. There are ways to mitigate these problems (detailed later). The more dimensions your data have (the more different aspects about your dinosaur you want the network to learn), the more data you need. This is sometimes referred to as the curse of dimensionality. ... [Pg.49]

If these trivial systems are further substituted, however, they are treated as substituted benzenes. [Pg.43]


See other pages where Trivial systems is mentioned: [Pg.893]    [Pg.650]    [Pg.8]    [Pg.893]    [Pg.278]    [Pg.162]    [Pg.374]    [Pg.92]    [Pg.584]    [Pg.99]    [Pg.151]    [Pg.135]    [Pg.15]   
See also in sourсe #XX -- [ Pg.43 ]




SEARCH



© 2024 chempedia.info