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131.
132.
J. W. Tomm H. Schmidt L. Werner K. H. Herrmann 《Crystal Research and Technology》1990,25(9):1069-1078
Material and structural parameters of narrow-gap p-type HgCdTe are investigated by infrared photoluminescence. The method is used for analyzing the energy gap, the carrier lifetime, and heterointerfaces and to monitor defects like inclusions. The spatial distribution of the quantities mentioned has been investigated by applying the mapping technique known for III – V semiconductors. The methods is a powerful tool for both crystal growth and device manufacturing. 相似文献
133.
134.
Werner Baltes 《Nachrichten aus der Chemie》1981,29(6):361-361
135.
136.
Scenario Reduction Algorithms in Stochastic Programming 总被引:4,自引:0,他引:4
We consider convex stochastic programs with an (approximate) initial probability distribution P having finite support supp P, i.e., finitely many scenarios. The behaviour of such stochastic programs is stable with respect to perturbations of P measured in terms of a Fortet-Mourier probability metric. The problem of optimal scenario reduction consists in determining a probability measure that is supported by a subset of supp P of prescribed cardinality and is closest to P in terms of such a probability metric. Two new versions of forward and backward type algorithms are presented for computing such optimally reduced probability measures approximately. Compared to earlier versions, the computational performance (accuracy, running time) of the new algorithms has been improved considerably. Numerical experience is reported for different instances of scenario trees with computable optimal lower bounds. The test examples also include a ternary scenario tree representing the weekly electrical load process in a power management model. 相似文献
137.
In the anionic polymerization of polar monomers the nature of active centres is considerably influenced by the reaction conditions. In a survey, the present state of knowledge is represented and discussed for the polymerization of acrylonitrile. Analogous problems of methyl methacrylate and vinylpyridine polymerization are included in the considerations. 相似文献
138.
P. Werner N. V. Rozhanski A. V. Arslambecov J. Heydenreich 《Crystal Research and Technology》1984,19(12):1589-1595
The crystal structure of thermally oxidized Ge was investigated by high-resolution electron microscopy (HREM), mainly the interface Ge/oxide. Under special conditions the reaction Ge + O2 → GeO2 which takes place at (111) surface planes leads to suitable thin crystal regions. The GeO2 occurs normally as amorphous films on the crystal surface. Furthermore, hexagonal GeO2 can grow at the interface Ge/oxide by a topotaxial reaction; the orientation relation between these two lattices was ascertained. Intensive electron irradiation was used to initiate and to observe structure changes in boundary regions. 相似文献
139.
Iron Precursor Decomposition in the Magnesium Combustion Flame: A New Approach for the Synthesis of Particulate Metal Oxide Nanocomposites 下载免费PDF全文
Amir R. Gheisi Matthias Niedermaier Gerold Tippelt Werner Lottermoser Johannes Bernardi Oliver Diwald 《Particle & Particle Systems Characterization》2017,34(10)
Powders of Fe–Mg–O nanocomposite particles have been grown using a novel chemical vapor synthesis approach that employs the decomposition of a metalorganic precursor inside the metal combustion flame. After annealing in controlled gas atmospheres composition distribution functions, structure and phase stability of the obtained magnesiowüstite nanoparticles are measured with a combination of techniques such as inductively coupled plasma‐optical emission spectroscopy, energy dispersive X‐ray spectroscopy, X‐ray diffraction, and scanning and transmission electron microscopy. Complementary Mössbauer spectroscopy measurements reveal that depending on Fe loading and temperature of annealing either metastable and superparamagnetic solid solutions of Fe3+ ions in periclase (MgO) or phase separated mixtures of MgO and ferrimagnetic magnesioferrite (MgFe2O4) nanoparticles can be obtained. The described combustion technique represents a novel concept for the production of mixed metal oxide nanoparticles. Adressing the impact of selected annealing protocols, this study underlines the great potential of vapor phase grown non‐equilibrium solids, where thermal processing provides means to trigger phase separation and, concomitantly, the emergence of new magnetic properties. 相似文献
140.
Alexander P. Chetverikov Werner Ebeling Manuel G. Velarde 《Physica D: Nonlinear Phenomena》2011,240(24):1954-1959
Nano-scale soliton-like supersonic, intrinsic localized excitations in two-dimensional atomic anharmonic lattice layers are here considered. We study the propagation, the velocity and other soliton-like features at head-on collisions of such lattice excitations created by using suitable initial mechanical and thermal conditions. Noteworthy is that narrow, highly-energetic solitons moving along one lattice row are very robust, accompanied by weak anti-phase oscillations in the lateral direction. 相似文献