Restricted overlapping balancing domain decomposition methods and restricted coarse problems for the Helmholtz problem

Overlapping balancing domain decomposition methods and their combination with restricted additive Schwarz methods are proposed for the Helmholtz equation. These new methods also extend previous work on non-overlapping balancing domain decomposition methods toward simplifying their coarse problems and local solvers. They also extend restricted Schwarz methods, originally designed to overlapping domain decomposition and Dirichlet local solvers, to the case of non-overlapping domain decomposition and/or Neumann and Sommerfeld local solvers. Finally, we introduce coarse spaces based on partitions of unity and planes waves, and show how oblique projection coarse problems can be designed from restricted additive Schwarz methods. Numerical tests are presented.     

ΝΗ<Subscript>3</Subscript> decomposition in a proton conducting solid electrolyte cell

The reaction of NH₃ decomposition was studied on Ag in a proton conducting double chamber cell-reactor. The proton conductor was a strontia-ceria-ytterbia (SCY) perovskite of the form SrCe_0.95Yb_0.05O_3−α. The reaction was studied at 350–700 °C and atmospheric total pressure. The proton transference number (PTN) was calculated by simultaneous measurement of the imposed current and the proton flux and it was found to vary between 0.5 and 0.7. The effects of imposed current, temperature and inlet gas composition on the reaction rate and the PTN, were examined. Although the faradaic efficiency (Λ) remained near unity in all experiments, reaction rate enhancements (ρ) as high as 57 were achieved. An up to 90% decrease in the activation energy of the reaction was observed when protons were electrochemically “pumped” away from the catalyst.     

Characterization of supported Pd-Pt catalysts by chemical probes

The temperature programmed (palladium) hydride decomposition appeared very effective method for diagnosing the extent of alloying in Pd-Pt/SiO₂ catalysts. Introduction of Pt to Pd catalysts moves the TPHD peak gradually towards lower temperatures and the shift in hydride decomposition peak is accompanied by a decrease in the amount of released hydrogen. The catalysts prepared the direct redox method showed much better alloy homogeneity than the samples prepared by coimpregnation. The results of probing with other techniques, i.e. catalytic probing with hydrodechlorination of CCl₂F₂ and XRD, were in line with TPHD data. The catalytic probing showed the presence of synergistic effect, a clear indication of Pd-Pt mixing. XRD data of post-reaction samples showed carbon incorporation into Pd-rich phase, whereas separate Pt-rich phase did not experience any bulk carbiding.     

热分解法制备钛酸铅镧薄膜及其电性能研究

本文研究了用金属有机物热发解法制备ＰＬＴ８薄膜的工艺过程和基片对薄膜结构的影响，并且给出了铁电性能的测量结果。     

采用奇异值分解设计广义系统的最优滤波器

本文讨论广义离散随机线性系统的状态估计问题，通过矩阵奇值分解，本文给出了一种设计降阶最优滤波器的实用方法，该方法同时还得到了动态系统和量测系统的干扰噪声的估计。     

The desorption of O2 during NO and N2O decomposition on Cu- and Fe-zeolites

The decomposition of NO and of N₂O over a CuZSM-5 zeolite and a Fe-mordenite, respectively, has been studied using tracer techniques. The results demonstrate the high mobility of the lattice oxygen ions in self-diffusion. They afford a possible explanation for the problem of how two extralattice oxygens located at positions remote from each other may combine to form the O₂ molecules which are spontaneously desorbed in these redox reactions. They show that a portion of the lattice oxygen mixes into the O₂ released on decomposition. The data also show that N¹⁸O and N₂ ¹⁸O undergo exchange with the catalyst oxygen under reaction conditions.On leave from Central Research Institute for Chemistry, Hungarian Academy of Sciences, H-1525 Budapest, Hungary.     

TPC方法研究催化剂热分解动力学

设计了ＴＰＣ方法研究催化剂前驱体的热分解；对ＴＰＣ方法求取催化剂的热分解动力学方程进行了理论推导；采用ＴＰＣ方法试验求得了Ｎｉ－Ｚｎ／Ｃ催化剂的热分解动力学参数。试验表明，ＴＰＣ方法能直观、灵敏、方便地反映催化剂活性组份前驱体的本征热分解。     

Optimized Schwarz methods without overlap for highly heterogeneous media

In this paper an original variant of the Schwarz domain decomposition method is introduced for heterogeneous media. This method uses new optimized interface conditions specially designed to take into account the heterogeneity between the sub-domains on each sides of the interfaces. Numerical experiments illustrate the dependency of the proposed method with respect to several parameters, and confirm the robustness and efficiency of this method based on such optimized interface conditions. Several mesh partitions taking into account multiple cross points are considered in these experiments.     

Method of increasing the output signal-to-noise ratio in passive multi-element antenna arrays

A method of processing complex signals in passive multi-element antenna arrays based on an analysis of the natural values of the correlation matrix of the signal is considered. By means of the method it is possible to substantially increase the output signal-to-noise ratio. An iterational process by means of which optimal estimators of both the signal and the amplitude-phase distribution may be obtained, is proposed. Theoretical estimators of the efficiency of the method are given. It is proved that, in terms of the efficiency, the approach considered in the article comes close to the technique of matched filtration. Results of statistical modeling that confirm the statistical results are presented.     

A new approach to the decomposition of Boolean functions by the method of <Emphasis Type="Italic">q</Emphasis>-partitions. III. Joint decomposition of a function system

The paper considers the set-theoretical approach to the joint decomposition of systems of Boolean functions of variables specified in different representation forms. The approach is based on the method of q-partitions of conjuncterms and concept of decomposition clones. Theorems on joint decomposition of a system of full and partial functions are formulated. The approach is illustrated by examples. Parts I and II of this article are published in No. 5 (2001) and No. 1 (2002). __________ Translated from Kibernetika i Sistemnyi Analiz, No. 2, pp. 39–58, March–April 2007.