Effective annihilation

In its sentence, the Tubingen County Court decided the book Grundlagen zur Zeitgeschichte should be withdrawn from circulation, effectively annihilated and that the author and publisher should be punished. This, after prominent German historians had submitted to the court expert opinions to the effect that the book held to scientific standards and that therefore the authors, editor, publisher, sellers, printer and purchasers were owed the right of freedom of science and the right of freedom of expression (see chapter 11.4.2.).554 It did not help ... 

The theory of isotropic three-dimensional diffusion allows yss to be expressed by a product of the exciton diffusion coefficient Ds and the effective annihilation capture radius Rs [189],... 

When an accurate wave function is calculated by some effective method, we can calculate an accurate annihilation rate with the use of an effective annihilation operator [5] ... 

The effects of annihilation on Pn(t) is apparent in Fig. 9 and iiiustrates the highiy nonexponential behavior expected for the delayed fluorescence. The effective annihilation rate was defined by Webber and Swenberg (11) as... 

S-S annihilation phenomena can be considered as a powerful tool for investigating tire exciton dynamics in molecular complexes [26]. However, in systems where tliat is not tire objective it can be a complication one would prefer to avoid. To tliis end, a measure of suitably conservative excitation conditions is to have tire parameter a< )T < 0.01. Here x is tire effective rate of intrinsic energy dissipation in tire ensemble if tire excitation is by CW light, and T = IS tire... 

Amorphous Silicon. Amorphous alloys made of thin films of hydrogenated siUcon (a-Si H) are an alternative to crystalline siUcon devices. Amorphous siUcon ahoy devices have demonstrated smah-area laboratory device efficiencies above 13%, but a-Si H materials exhibit an inherent dynamic effect cahed the Staebler-Wronski effect in which electron—hole recombination, via photogeneration or junction currents, creates electricahy active defects that reduce the light-to-electricity efficiency of a-Si H devices. Quasi-steady-state efficiencies are typicahy reached outdoors after a few weeks of exposure as photoinduced defect generation is balanced by thermally activated defect annihilation. Commercial single-junction devices have initial efficiencies of ca 7.5%, photoinduced losses of ca 20 rel %, and stabilized efficiencies of ca 6%. These stabilized efficiencies are approximately half those of commercial crystalline shicon PV modules. In the future, initial module efficiencies up to 12.5% and photoinduced losses of ca 10 rel % are projected, suggesting stabilized module aperture-area efficiencies above 11%. 

Dichlorophenoxyacetic acid (2,4-D) is a selective effect herbicide of widely applied for annihilation of bichromatic weeds in sowings of gramineous cultures. 

It is clear that if all the program counters arc unoccupied (i.e. are in the state I 0 >), nothing at all happens all terms in the Hamiltonian start out with an annihilation operator, and all states thus remain in the state 0 > for all time. If we assume that only one of the sites 0,1,... fc sites is occupied, however, we see that only one site will always be occupied, though not necessarily the same site at different times. If we think of the occupied site, say the first site 0, as a cursor, the Hamiltonian effectively moves the cursor along the program counter sites while the operators Ai operate on the register n. Feynman shows how, by the time the cursor arrives at the final site fc, the n register has been multiplied by the entire set of desired operators Tj, T2,..., A -... 

Various types of intermediate behaviour embodying features of more than one of these effects can be visualized. In addition to the considerations (i)—(iii) above, the interface may behave as a source or sink for the creation and/or annihilation of imperfections such as lattice defects and electrons, which can be important participants in the overall change (for clarity, such effects have not been included in Fig. 8). The decomposition characteristics of many solids are influenced by externally supplied energy such as irradiation, cold working, etc. 

Here the indices a and b stand for the valence orbitals on the two atoms as before, n is a number operator, c+ and c are creation and annihilation operators, and cr is the spin index. The third and fourth terms in the parentheses effect electron exchange and are responsible for the bonding between the two atoms, while the last two terms stand for the Coulomb repulsion between electrons of opposite spin on the same orbital. As is common in tight binding theory, we assume that the two orbitals a and b are orthogonal we shall correct for this neglect of overlap later. The coupling Vab can be taken as real we set Vab = P < 0. 

There is also the normal dipole selection rule in operation, as illustrated in Figure 5.48, due to Liith (1981). Any dipole at a surface induces an image charge within the surface. If the dipole orientation is normal to the surface, the effect is enhanced by the image dipole. If, however, the orientation is parallel to the surface, the effect is annihilated by the image dipole. This orientation selection rule thus strongly favours normally oriented dipoles. 

Certain metal salts effectively reduce the photoactivity of titanium dioxide pigments. Combination of these salts with an appropriate antioxidant and/or ultraviolet stabilizer provided highly efficient stabilization of polypropylene. The deactivation/ stabilization performance of the metal salts is adequately explained on the basis of their decomposition of hydrogen peroxide at the pigment surface and by annihilation of positive holes in the pigment crystal lattice. 

Another type of absorption is also possible, i.e., exciton absorption which enriches the crystal in free excitons if the latter annihilate then on the lattice defects, causing a change in the charged state of the defects and leading to the appearance of free carriers in the crystal. In this case photoconduction arises as a secondary effect. 

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