聚合物包覆热分解法制备纳米氧化锌的工艺研究

采用聚合物包覆热分解法化学工艺制备了纳米氧化锌，对其工艺进行系统的比较研究，对所得粉体进行XRD与SEM表征。发现利用该工艺所得粉体为六方晶系纤锌矿结构（空间群为P63mc）的纳米氧化锌。该方法制备的氧化锌衍射峰尖锐，表明此种方法合成的氧化锌结晶程度高。所得的氧化锌粉体XRD图谱中没有杂质衍射峰，说明产物纯度都很高。产品SEM表征结果显示了此工艺产物在形貌方面的高度一致性——为菊花状氧化锌纳米杆团簇，对产物形貌形成的原因做了探讨。     

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。     

A new synthesis procedure for titanium-containing zeolites under strong alkaline conditions and the catalytic activity for partial oxidation and photocatalytic decomposition

A new synthesis procedure for titanium-containing aluminosilicate zeolites has been obtained using a clear colloidal dispersion (sol) which was prepared with titanium isopropoxide, water, hydrochloric acid and colloidal silica, Ludox. When NaY, KL, offretite, mordenite and ZSM-5 zeolites were crystallized from the sol following conventional hydrothermal crystallization procedures, all the aluminosilicate zeolites showed the same X-ray absorption fine structure at the Ti K edge indicating framework Ti. The zeolites showed remarkable catalytic activity for the partial oxidation of cyclohexene using H₂O₂ as an oxidant and the photocatalytic decomposition of trichloroethene using water.     

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。     

A FETI-like domain decomposition method for coupling finite elements and boundary elements in large-size problems of acoustic scattering

Numerical simulations of acoustic scattering in the frequency domain based on hybrid methods coupling finite elements and boundary elements are the most suited for dealing with problems involving wave propagation in inhomogeneous media. Furthermore, it is necessary to resort to high performance computing to effectively solve the large size problems. However, the direct coupling yields a linear system with a matrix which is partly dense and partly sparse and thus not adapted to high performance computing. To avoid this difficulty, we present a new iterative method constructed from a non overlapping domain decomposition technique.     

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.