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71.
72.
We present a novel approach to calculating Low-Energy Electron Diffraction (LEED) intensities for ordered molecular adsorbates. First, the intra-molecular multiple scattering is computed to obtain a non-diagonal molecular T-matrix. This is then used to represent the entire molecule as a single scattering object in a conventional LEED calculation, where the Layer Doubling technique is applied to assemble the different layers, including the molecular ones. A detailed comparison with conventional layer-type LEED calculations is provided to ascertain the accuracy of this scheme of calculation. Advantages of this scheme for problems involving ordered arrays of molecules adsorbed on surfaces are discussed. 相似文献
73.
Coventry DN Batsanov AS Goeta AE Howard JA Marder TB Perutz RN 《Chemical communications (Cambridge, England)》2005,(16):2172-2174
The selectivity of the iridium boryl complex-catalysed reaction of pyrene and perylene with B2(pin)2 (pin = OCMe2CMe2O) has been employed in the synthesis of D(2h)-symmetry pyrene-2,7-(Bpin)2 and D(4h)-symmetry perylene-2,5,8,11-(Bpin)4 providing direct borylation of positions which are otherwise difficult to derivatise. 相似文献
74.
An extended dipyridyl ligand (L1) capable of hydrogen bonding with guest species via urea functionalities has been designed and synthesised. Assembly of a silver(I) coordination polymer of L1 is dependent on the nature of the hydrogen bond acceptor in a logical extension of the monopyridyl analogue. 相似文献
75.
We present a version of the Sharkovskii cycle coexistence theorem for differential equations. Our earlier applicable version is extended here to hold with the exception of at most two orbits. This result, which (because of counter-examples) cannot be improved, is then applied to ordinary differential equations and inclusions. In particular, if a time-periodic differential equation has -periodic solutions with , for all , then infinitely many subharmonics coexist.
76.
Andres del Junco 《Probability Theory and Related Fields》1980,52(2):193-202
Summary There exists a finitary code from any stationary ergodic Markov random field to any i.i.d. random field of strictly lower entropy. 相似文献
77.
We observe a rapid temperature variation and an electric field dependence of the d.c. conductivity in a carefully characterized sample of P doped Si. These results, combined with measurements of Raman scattering, far-infrared absorption and magnetic susceptibility, indicate a large characteristic electronic length (104 times the donor Bohr radius) at a donor concentration just below the critical density of the metal-insulator transition. 相似文献
78.
Careful observation of the diamagnetic shielding signal in small fields applied along the a-axis of deuterated (TMTSF)2ClO4 crystals reveal a systematic dependence of the diamagnetic susceptibility on the thickness (b- and c-dimensions) of the crystals, which we explain by a macroscopically large value of 0.004 cm for the London penetration depth. 相似文献
79.
80.