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111.
Polarographic reduction of 2-amino-4-aryl-5-phenylazothiazoles takes place in a single 2-electron transfer, giving a diffusion-controlled irreversible wave in the pH range 2.0-10.0. Substituents in the 4-position of the thiazole moiety shift the half-wave potential through conjugation of the system. A correlation of E(sol;1 2 ) with the Brown and Hammett substituent constant has also been established. 相似文献
112.
113.
Rita Menicagli Corrado Malanga Luciano Lardicci Laura Tinucci 《Tetrahedron letters》1980,21(47):4525-4528
2-Ethoxy-5-alkyl-3,4-dihydro-2H-pyrans react with Albui3 and through a regioselective hydride addition provide substituted cyclobutylmethanols in very good yields. 相似文献
114.
The generation of a circular fringe system of Newton rings' type with dark fringe at the centre is described. Such fringes are localized at infinity and are produced by a pair of longitudinally displaced mutually complimentary diffusers. Experimental results under various displacement configurations have been presented. 相似文献
115.
S. K. Goyal 《The Journal of the Operational Research Society》1973,24(3):391-401
A first attempt at applying OR techniques and approaches in a fine art printing firm manufacturing greeting cards is reported in this paper. The problem of economic production of cards is formulated and four related methods are presented, the fourth being a probabilistic model with possibly wider applications in the fashion industry 相似文献
116.
S.K. Goyal 《European Journal of Operational Research》1980,4(3):185-188
The search procedure developed in this paper is typically applicable in those inventory systems where a product is packaged immediately after manufacture into a number of container sizes and the packaged items of similar sizes are sold under more than one brand name. The most common example of such items can be seen in supermarkets where grocery items of identical characteristics (produced by the same manufacture) are available under the supermarket's own brand and under the manufacturer's nationally advertised brand. An example has been solved to illustrate the method. 相似文献
117.
118.
Experimentally observed phonon softening of the 520 cm-1 Raman line in ultra-heavily doped n-Si is attributed to the electron-phonon self-energy effects as well as change in lattice force constants of the alloy system. 相似文献
119.
120.
Wahl U Rita E Correia JG Marques AC Alves E Soares JC;ISOLIDE Collaboration 《Physical review letters》2005,95(21):215503
Arsenic has been reported in the literature as one of the few p-type dopants in the technologically promising II-VI semiconductor ZnO. However, there is an ongoing debate whether the p-type character is due to As simply replacing O atoms or to the formation of more complicated defect complexes, possibly involving As on Zn sites. We have determined the lattice location of implanted As in ZnO by means of conversion-electron emission channeling from radioactive (73)As. In contrast to what one might expect from its nature as a group V element, we find that As does not occupy substitutional O sites but in its large majority substitutional Zn sites. Arsenic in ZnO (and probably also in GaN) is thus an interesting example for an impurity in a semiconductor where the major impurity lattice site is determined by atomic size and electronegativity rather than its position in the periodic system. 相似文献