Bis systems

Figure 11. Temperature dependence of the potential of the two-phase plateaus in the Li-Sb and Li-Bi systems [41].

Clavilier J, Femandez-Vega A, Feliu JM, Aldaz A. 1989b. Heterogeneous electrocatalysis on well-defined Pt surfaces modified by controlled amounts of irreversible adsorbed adatoms. Part I. Formic acid oxidation on Pt(lll)-Bi system. J Electroanal Chem 258 89-100. 

In the Au-Bi system the compound Au2Bi is stable in a restricted range of temperature only it is formed by a peritectic reaction (371°C) and, at a lower temperature (116°C), it is decomposed according to the eutectoidal reaction Au2Bi — (Au) + (Bi). In the Zn-Te system, finally, we have the congruently melting compound ZnTe. In this system a miscibility gap in the liquid state may also be noticed. 

The synthesis of stable complexes with transition metal-phosphorus triple bonds is of fundamental importance and opens a novel chapter of a special field of coordination chemistry. The synthesis of analogous complexes with ligands of the heavier homologues like arsenic has partially been carried out [6], while for antimony and bismuth, the elusive M=Sb and M=Bi systems have now moved within reach. Moreover, the experimental and theoretical... 

The procedure to be described here was originally developed by Cha. The basic principle of his approach is to treat the rapid-equilibrium segment as though it were a single enzyme species at steady state with the other species. Let us consider the hybrid Rapid-Equilibrium Random-Ordered Bi Bi system ... 

A sequential enzyme-catalyzed reaction scheme in which two substrates (A and B) react and form a single product and in which the substrates bind to the enzyme in a distinct order (i.e., only A and the product P can bind to the free enzyme). The reverse scheme of this mechanism is the ordered Uni Bi system. (See also Ordered Uni Bi Mechanism)... 

The Bi system, which contains three phases of general formula... 

BaPbi.xSbx03, 226, 382,406-10 comparison with Bi-system, 407 crystal growth, 233 ionization potentials, 408 structure, 409... 

Fig. 85.—Binary Fig. 86.— Fig. 87.—Bi-System Ba(N02)2 Binary nary System -AgNO,. Svstem Ca(NO )2...

This example shows how difficult the reaction-diffusion experiments are, even with most suitable binary systems. The latter means the minimal influence of (i) thermal expansion and (zz) volume effect associated with compound formation. In the Ni-Bi couple the coefficients of thermal expansion of the components are identical, " while the volume effect is within a range typical of intermetallic compounds. With respect to the influence of thermal expansion, the Ni-Bi system is preferable to the Al-Mg one in which the coefficients of thermal expansion of the components are slightly different. 

VALENCY-VARIABLE CATION Co-DOPING AND Sn-Cl-DOPING IN Bi-SYSTEM 2223 PHASE SUPERCONDUCTOR... 

Concerning high Tc superconductor of Bi-system, recent studies [1-4] on its microstructure, crystal grain size, the effect of the preparation condition on its properties, phase transformation, preparation of pure 2223 phase and doping etc were reported. 

In Bi-system, there exist a series of superconducting phases. Among them the Bisystem 2223 phase possesses relatively high Tc (Tc=110K). It is a prospective superconductor material in practical application of large electric current. Therefore, the mechanism of superconductivity and formation of the 2223 phase have been of interest for a long time. 

Figure 5. Structure of half of the single cell of the 2223 phase for the Bi-system.

Doping of valence-variable cation Co speeds up the formation of the high T, 2223 phase in Bi-system. Doping with both cation Sn and anion Cf speeds up the formation of high Tc 2223 phase further. There are Cu, Cu, Bi and Bi cations in the high Tc 2223 phase, but Cu is not found. 

Table 6. Bending Tests on bi Systems with and without Ta Interlayer...

If the conversion of AB to EPQ is as rapid as the dissociation reactions, then steady-state assumptions must be used to derive the velocity equation. In xnultireactant systems, the rapid equilibrium and steady-state approaches do not yield the same final equation. For the ordered Bi Bi system, a steady-state derivation yields ... 

Figiirc 4-44 Ordered Bi Bi system, (a) l/v versus 1/[A] at different fixed B concentrations, (b) 1/v-axis intercept repbt. (c) Slofei/A replot. Although the nomenclature is different. Figure 4-44 is identical to Figure 4-42. Thus, initial velocity measurements alone will not discriminate between random and ordered mechanisms. 

The catalytic reaction of lipases follow the so called ping-pong bi-bi mechanism, a double displacement mechanism. This is a special multisubstrate reaction in which, for a two-substrate, two-product (i.e., bi-bi) system, an enzyme reacts with one substrate to form a product and a modified enzyme, the latter then reacting with a second substrate to form a second, final product, and regenerating the original enzyme (ping-pong). 

Diverse investigations of the miscellaneous ternary systems Sn-Pb-Cd, Sn-Ga-In, Sn-Sb-Bi, " Pb-In-Sb, and Pb-Bi-Hg have been undertaken by a number of Russian authors. It was concluded from the results of an ultrasonic study of Sn-Pb-Cd liquid solutions that intermetallic compounds are not formed in this system. Thermodynamic analysis of the Sn-Sb-Bi system shows both positive and negative deviations from ideality in the liquid state.Finally, interpretation of the atomic distribution functions of Pb-In-Sb solutions has led to the conclusion that the melts have a microheterogeneous structure in the fusion... 

The versatility of this general procedure is further illustrated by the synthesis of the bis system (17) (42). This dinuclear complex was obtained by template condensation of the precursor complex, [NiaL] LH4 = tetrakis[l-(3-methylisothiosemicarbazono)ethyl]-ethane, with 3-ethoxyacrylaldehyde in DMF and followed by the usual oxidative coupling/deprotonation process. The X-ray structure of the diamag-... 

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