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81.
Erich Heymann 《Colloid and polymer science》1934,66(2):229-235
Ohne Zusammenfassung 相似文献
82.
A.J. Dos santos-García J. van Duijn G. Heymann M.Á. Alario-Franco 《Journal of solid state chemistry》2008,181(5):1167-1175
The synthesis, structure and microstructure of the IrSr2TbCu2O8 cuprate showing metamagnetic properties are described. The sample was prepared at high temperatures and pressures up to 9.2 GPa. The structure is tetragonal, showing a 1212 type structure, that derives from the classical YBaCuO superconductor structure, replacing the tetracoordinated square planar copper [Cu-O4] in the “chains” by octahedral [Ir-O6] groups that form a perovskite-like layer in the basal plane of the unit cell. A “simple” cell, ∼ap×ap×3ap, where ap is the basic perovskite unit cell parameter (ap∼3.8 Å), is supported by X-ray powder diffraction (XRD) and a so-called “diagonal” one, ∼√2ap×√2ap×3ap, by SAED; a microdomain texture of latter cell and a series of very interesting extended defects have been observed by HREM. Magnetic susceptibility measurements show a magnetic transition, TN∼6 K, with negative Weiss temperature, that indicates antiferromagnetic interactions among the Tb moments. The magnetic structure has been determined by neutron diffraction. A detailed magnetic study has revealed a metamagnetic behavior, something not previously observed in this type of cuprates. Specific heat and resistivity measurements have also been performed to characterize the transition. 相似文献
83.
An algorithm is proposed to calculate the minimum energy path (MEP). The algorithm is based on a variational formulation in which the MEP is characterized as the curve minimizing a certain functional. The algorithm performs this minimization using a preconditioned steepest-descent scheme with a reparametrization step to enforce a constraint on the curve parametrization. 相似文献
84.
85.
E. Heymann 《Colloid and polymer science》1926,38(1):58-59
Ohne Zusammenfassung 相似文献
86.
U. Amador J.M. Gallardo-Amores G. Heymann H. Huppertz E. Morán M.E. Arroyo y de Dompablo 《Solid State Sciences》2009,11(2):343-348
Olivine-LiCoXO4 (X = P, As) compounds might transform to the denser spinel-type and Na2CrO4-type structures under pressure. In this work, the relative energetic stability of the three polymorphs and the pressure of the possible polymorphic transformations are investigated combining experiments and first principles calculations. Olivine-LiCoAsO4 is predicted to transform to the Na2CrO4-like structure at 0.4 GPa and to the spinel structure at 5.8 GPa (0 K). Quenching HP/HT experiments show that olivine-LiCoAsO4 treated at 6 GPa/1173 K transforms to the spinel-like structure. Computational results indicate that olivine-LiCoPO4 transforms to the Na2CrO4-like form at around 4 GPa (0 K), the latter being the stable form till very high pressures (21.6 GPa). In good agreement with this, olivine-LiCoPO4 when subjected to 6 GPa/1173 K and 15 GPa/1173 K is converted to the Na2CrO4-type polymorph. Crystallographic data of the new compound LiCoPO4 within the Na2CrO4 structural type are provided. 相似文献
87.
An instability of a magnetized plasma column in the frequency range has been identified as an ion acoustic one. The waves are azimuthally driven by the electron diamagnetic velocity due to the radial gradient of a fast electron tail. The strongest peaks in the frequency spectrum correspond to m = 6 or 8 wave lengths on one turn. This selection can be explained as an optimum value between increasing growth rate and the resonance disturbing phase mismatch at higher mode numbers. 相似文献
88.
A linear pursuit game with a trap, the location of which is unknown to the evader, is defined and investigated. The cases in which one of the players has complete energy dominance over his adversary are solved completely. In the general case, when no player dominates, the solution is indicated for the two-stage game.This research was supported in part by the Technion Fund for promotion of research. 相似文献
89.
Combat games 总被引:1,自引:0,他引:1
M. D. Ardema M. Heymann N. Rajan 《Journal of Optimization Theory and Applications》1985,46(4):391-398
We propose a mathematical formulation of a combat game between two opponents with offensive capabilities and offensive objectives. Resolution of the combat involves solving two differential games with state constraints. Depending on the game dynamics and parameters, the combat can terminate in one of four ways: (i) the first player wins, (ii) the second player wins, (iii) a draw (neither wins), or (iv) joint capture. In the first two cases, the optimal strategies of the two players are determined from suitable zero-sum games, whereas in the latter two the relevant games are nonzero-sum. Further, to avoid certain technical difficulties, the concept of a -combat game is introduced.Dedicated to G. LeitmannThe first author wishes to acknowledge the friendship and guidance of George Leitmann, beginning in the author's student days at Berkeley and continuing to the present time. All the authors thank George Leitmann for many recent fruitful discussions on differential games.on sabbatical leave from Technion, Israel Institute of Technology, Haifa, Israel. 相似文献
90.
Kurt Heymann Wolfgang Riedel Günter Woldt 《Angewandte Chemie (International ed. in English)》1970,9(6):425-433
Electroplated plastics combine many advantages of plastics and of metals; they have the low weight and ease of shaping of plastics, together with the luster, hardness, and electrical conductivity of metals. An important part of any process for the electroplating of plastics is a pretreatment to ensure good adhesion of the metal film. Etch activation in the straight-through method requires only six steps for pretreatment. 相似文献