Big Chemical Encyclopedia

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

Articles Figures Tables About

Fibonacci sequence

One way to solve the problem of unphysically short atomic distances is to project onto the Rpm subspace only those grid points included in a selected strip (gray area), with width of a (cos a + sin a) in the A per subspace. The slope of RPai shown in Fig. 1 is 0.618..., an irrational number related to the golden mean [( /5 + l)/2 = 1.618...]. As a result, the projected ID structure contains two segments (denoted as L and S), and their distribution follows a ID quasiperiodic Fibonacci sequence [2] (c.f. Table 1). From another viewpoint, the ID quasiperiodic structure on the par subspace can be conversely decomposed into periodic components (square lattice) in a (higher) 2D space. The same strip/projection scheme holds for icosahedral QCs, which are truly 3D objects but apparently need a more complex and abstract 6D... [Pg.14]

Table 1 The Fibonacci sequence and its relationship to the golden mean, 1.618... Table 1 The Fibonacci sequence and its relationship to the golden mean, 1.618...
The Fibonacci sequence can be generated by transformations of L LS and S—>L in each cycle. L/S represents the sequence of ACs that can exist for any QC system. With increasing order, the L/S ratio converges to the golden mean value... [Pg.15]

PHI is the ratio of any two sequential numbers in the Fibonacci (V sequence. If you take the numbers 0 and 1, then create each subsequent number in the sequence by adding the previous two numbers, you get the Fibonacci sequence. For example, 0, 1,1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144. Ifyou sum the squares of any series of Fibonacci numbers, they will equal the last Fibonacci number used in the series times (10) the next Fibonacci number. This property results in the Fibonacci spiral seen in everything from seashells to galaxies, and is written mathematically as l2 + l2 + 22 + 32 + 52 = 5 x 8. [Pg.194]

Fibonacci sequence—a progression famous not only because the sum of adjacent terms equaled the next term, but because the quotients of adjacent terms possessed the astonishing property of approaching the number 1.618—PHI ... [Pg.196]

It should be remembered that all of these methods are very conservative, since they are all based on the assumption that nothing is known about the function y except that it is unimodal. If, as is often the case with physical systems, the function is known to be smooth and continuous, the engineer may wish to fit a curve to his points and estimate the maximum by ordinary differentiation. When doing this, however, it is worthwhile to locate the points according to the Fibonacci sequence so as to be able to shift to a Fibonacci search if the function does not behave according to preliminary estimates. [Pg.284]

Transforming to the rest-frame of the moving beam-particles the quantum mechanics of a spin-1/2 particle traversing the spin-precession apparatus is equivalent to the quantum mechanics of a stationary spin-1/2 particle perturbed by a sequence of external field pulses. Such a system was investigated by Luck et al. (1988). It was found that the quantum dynamics of a spin-1/2 particle perturbed by a sequence of pulses arranged according to a Fibonacci sequence is indeed very complicated. [Pg.115]

Between two such peaks is a sequence of further peaks of lower intensity that all lie in an infinite set of coincident interpenetrating Fibonacci sequences of arbitrarj origin. (They can be labelled through a projection from Euclidean two-dimensional space as described in the main text.)... [Pg.81]

The symmetry of quasicrystals can be represented by introducing a different perturbation function, which is based on the Fibonacci numbers. An infinite Fibonacci sequence is derived fi-om two numbers, 0 and 1, and is formed according to the following rule ... [Pg.91]

Figure 171. Explanation of maximum bubble grojvth by the catch-up mechanism resulting in a Fibonacci sequence " ... Figure 171. Explanation of maximum bubble grojvth by the catch-up mechanism resulting in a Fibonacci sequence " ...
Buoen et al. (9) reported that the dose-escalation schemes used in FTIH studies could be categorized as linear, logarithmic, modified Fibonacci, or miscellaneous. The latter included dose-escalation regimens in which the three standardized methods are combined. The authors reported that in 12 out of the 105 studies they reviewed a linear escalation method with fixed dose increment was used. A logarithmic dose-escalation scheme in which the relative dose increment was the same (e.g., 100%) was used in 22 studies. Four of the studies used a modified version of the Fibonacci escalation scheme, which is frequently used in cancer Phase 1 trials (6, 12-14). For most of the studies reviewed (i.e., 63.8%, or 67 studies) the dose-escalation schemes used did not seem to follow one particular scheme. In some cases two of the escalation schemes described above were combined (e.g., starting with a logarithmic escalation to convert later into a modified Fibonacci sequence), while for other studies, no escalation scheme was apparent. The doses appeared to have been chosen arbitrarily (11). [Pg.762]

Balaban, A.T. and Tomescu, 1. (1984) Chemical graphs. XL. Three relations between the Fibonacci sequence and the numbers of Kekule structures for non-branched cata-condensed polycyclic aromatic hydrocarbons. Croat. Chem. Acta, 57, 391-404. [Pg.982]

Throughout history, mathematicians have studied number patterns. Research Pascal s Triangle, Fibonacci and the Fibonacci Sequence, and the Golden Mean that was used by the Greeks in building the Parthenon. [Pg.141]

We observe (Figure 5) the expected linear increase of the FLI with time for all the orbits except the periodic one. For such orbit the FLI after a transitory linear increase becomes constant. Our aim is to explain such a behavior but before we study the relation between the FLI values and the order of periodic orbits. At this purpose we have computed the FLI as a function of time for a particular set of periodic orbits, the Fibonacci sequence. [Pg.139]

Let us recall that the Fibonacci sequence is the set of the successive rational ratios Pk/qk, k = 1,. ..oo, obtained when developing the golden... [Pg.139]

Figure 6. Variation with time of the FLI for a set of periodic orbits belonging to the Fibonacci sequence for the standard map with e = 0.9715. The rational ratios Pk/qk, k = 1,. ..7, are written in the figure near the corresponding FLI curve. The FLI curve which grows linearly with time all over the interval 0 < t < 5 106 iterations is obtained for the golden torus. Figure 6. Variation with time of the FLI for a set of periodic orbits belonging to the Fibonacci sequence for the standard map with e = 0.9715. The rational ratios Pk/qk, k = 1,. ..7, are written in the figure near the corresponding FLI curve. The FLI curve which grows linearly with time all over the interval 0 < t < 5 106 iterations is obtained for the golden torus.
When 7 >> 1, as it is in our study of the Fibonacci sequence, then the FLI, i.e. the supremum of the norm of v behaves like 7 (0), i.e. like a since vy(0) b. We remark that if vx(0) = 0 then vy(0) = b. A question remains about the transitory regime in which the FLI grows linearly with time. Actually, in order to reach its maximum value, the vector v(t) has to visit the ellipse from the the semi-minor to the semimajor axis, i.e. has to rotate at least an angle of 90 degrees. We were able to reproduce very well the evolution of the FLI with time of the seven Fibonacci periodic orbits (Lega and Froeschle 2000), confirming the validity of the simple model for explaining the behavior of the FLI for periodic orbits. [Pg.142]

Figure 10 shows that the values of 7 computed for the Fibonacci sequence are in a very good agreement with the values obtained with the LMA method. [Pg.145]

Figure 12-10. An STM image of a fivefold surface, size 1750 x 1750 nm, of i-AlPdMn. This image is taken from Ref. [9] (rotated by 180°), produced by J. Ledieu. In Ref. [26] a Fibonacci sequence of the step heights (circa) m = 4.08 A and / = 6.60 A was measured on the surface. We fix a marked subsequence of steps /, /, m, /, m from left-right, downwards, corresponding to a subsequence of the g fefeg -terminations in Ad(T ) from Figure 12-12 bottom). Numbers 193, 196 and 198 label the tiling fivefold planes in the model... Figure 12-10. An STM image of a fivefold surface, size 1750 x 1750 nm, of i-AlPdMn. This image is taken from Ref. [9] (rotated by 180°), produced by J. Ledieu. In Ref. [26] a Fibonacci sequence of the step heights (circa) m = 4.08 A and / = 6.60 A was measured on the surface. We fix a marked subsequence of steps /, /, m, /, m from left-right, downwards, corresponding to a subsequence of the g fefeg -terminations in Ad(T ) from Figure 12-12 bottom). Numbers 193, 196 and 198 label the tiling fivefold planes in the model...
For this thick, 3.88 A broad twofold layer the maximum of P2/(zx) is a perfectly flat plateau (Figure 12-13). The height of the plateau defines the effective density of terminations to be 0.086A (Table 12-4). The support of the width of the plateau equals W = (l/2) (see Figure 12-13) and encodes the Fibonacci sequence of twofold terminations with terrace heights S = y = 6.3 A and L = tS= 0.2 A. [Pg.271]

Figure 12-13. Density graph P2/(zx) of the thick twofold layers, with spacings ah -plane, 1.48 A, feg -plane, 0.92 A, fcg -plane, 1.48 A, afc -plane. The plateau of the graph defines the terminations. The width of the support of the plateau equals exactly /2 and defines the Fibonacci sequence of twofold... Figure 12-13. Density graph P2/(zx) of the thick twofold layers, with spacings ah -plane, 1.48 A, feg -plane, 0.92 A, fcg -plane, 1.48 A, afc -plane. The plateau of the graph defines the terminations. The width of the support of the plateau equals exactly /2 and defines the Fibonacci sequence of twofold...
Layers A and B themselves are two initial elements in the Fibonacci sequence. [Pg.77]

Herman nearly ripped the cap off his head. Don t you see it You re supposed to be the mathematical genius 1, 2, 3, 5,8, 13,21, 34. .. It s a Fibonacci sequence. Malcolm s mouth hung open. Of course. Today you are the genius After the first two, every number in the sequence equals the sum of the two previous numbers. He paused. Let s see, if I give you 55 pulses, you should experience something in your life from nine years ago. ... [Pg.53]

Although on this day they had a major breakthrough, the experiment was not as easy going as they thought. For one thing, the Fibonacci sequence allowed them only to approximately locate events to the nearest year. They had to find a way to localize events more precisely in time. The larger problem, however, was that the brain was so noisy that Herman and Malcolm only picked up brief incidents, memories, occasional events that they could understand and analyze. For all their dreams to... [Pg.53]

Notice that the number of males and females, and the total number of humans, begins to follow the well-known Fibonacci sequence ... [Pg.93]

To avoid any numerical precision problems that may arise with the Mulcrone formulation, R. Biyani has suggested a formulation involving only integer calculations. In particular, we can use a recursive function that computes the sex, s, of the xth person in the yth year using a previously generated sequence of the number of persons taken in each year (the Fibonacci sequence). The recursive relationship is ... [Pg.93]

My fascination with apocalyptic numbers started in my book Mazes for the Mind, in which I began a computer search for apocalypse numbers. These are Fibonacci numbers with precisely 666 digits. As you may know, the sequence of numbers 1, 1, 2, 3, 5, 8,..., is called the Fibonacci sequence, and it plays important roles in mathematics and nature. These numbers are such that, after the first two, every number in the sequence equals the sum of the two previous numbers, or F = F - + F 2. It turns out that the 3,184th Fibonacci number is apocalyptic, having 666 digits. For those of you who are numerologists, the apocalyptic number with all its digits is ... [Pg.97]

Note that denominators and numerators are formed from the Fibonacci sequence, in which each term is the sum of the previous two terms.)... [Pg.124]


See other pages where Fibonacci sequence is mentioned: [Pg.197]    [Pg.197]    [Pg.197]    [Pg.209]    [Pg.282]    [Pg.284]    [Pg.68]    [Pg.69]    [Pg.145]    [Pg.268]    [Pg.269]    [Pg.270]    [Pg.270]    [Pg.129]    [Pg.131]   
See also in sourсe #XX -- [ Pg.4 ]

See also in sourсe #XX -- [ Pg.115 ]

See also in sourсe #XX -- [ Pg.69 , Pg.81 ]

See also in sourсe #XX -- [ Pg.139 , Pg.140 , Pg.142 , Pg.145 ]

See also in sourсe #XX -- [ Pg.93 , Pg.97 , Pg.183 , Pg.184 ]

See also in sourсe #XX -- [ Pg.35 ]

See also in sourсe #XX -- [ Pg.35 ]

See also in sourсe #XX -- [ Pg.431 ]

See also in sourсe #XX -- [ Pg.156 , Pg.167 , Pg.168 ]




SEARCH



Fibonacci

Fibonacci sequence/chain

Golden Fibonacci sequences

© 2024 chempedia.info