Structure and Electrical Properties of Potassium-Doped Siloxane-Poly(oxypropylene) Ormolytes

The structure and the ionic conduction properties of siloxane-poly(oxypropylene) (PPO) hybrids doped with different potassium salts (KCF₃SO₃, KI, KClO₄ and KNO₂) are reported for two polymer molecular weights (300 and 4000 g/mol), labelled PPO₃₀₀ and PPO₄₀₀₀, respectively. The doping concentration, related to the concentration of the ether type oxygen of the PPO chain, is the same whatever the salt and verifies [O]/[K] = 20. Ionic room temperature conductivity shows the highest value for the KCF₃SO₃ doped PPO₄₀₀₀ hybrid (4 × 10^{–7 –1} cm^–1). The structure of these hybrids was investigated by X-ray powder diffraction (XRPD) and X-ray absorption spectroscopy (EXAFS and XANES) at the potassium K-edge (3607 eV). XRPD results show that the hybrid matrix is always amorphous and the formation of secondary potassium phases is observed for all the samples, except for the KCF₃SO₃ doped PPO₄₀₀₀ hybrid. EXAFS results evidence a good correlation between the ionic conductivity and the presence of oxygen atoms as first neighbours around potassium.     

Growth and characterization of high purity single crystals of barium ferrite

High purity single crystals of barium ferrite have been grown with the use of a BaO flux. The detected residual impurities have a total concentration of 130 ppm (wt), of which 100ppm is due to platinum. While the crystals exhibit occassional inclusions of a barium rich phase, the predominant microstructural defects are voids, which exhibit two geometries; one spherical and one hexagonal. Magnetic and resistivity measurements have yielded values which are comparable to those reported in the literature. Room temperature effective linewidth measurements at 10 GHz indicate that eddy current losses are dominant for disk shaped samples thicker than ≈0.3 mm. Room temperature FMR linewidth measurementson a sample 0.04 mm thick exhibit a linear frequency response between 55 and 90 GHz, which is consistent with a Landau-Lifshitz damping mechanism.     

Multiple-valued logic unit design using polarization-encoded optical shadow-casting

An efficient technique for the design of multiple-valued logic circuits using polarization-encoded optical shadow-casting is presented. As an illustration, a trinary full subtracter is designed using this technique. The resulting logic unit is compared with those obtained by using other algorithms.     

A search for the I peak at 2.60 GeV/c2 in 12 GeV/c pp interactions in the CERN 2 m HBC

In a study of 12 GeV/c$\text{p}$p interactions in the CERN 2 m HBC, we have searched for a narrow K3π state. Contrary to an investigation of 12 GeV/c$\text{p}$p interactions in the CERN BEBC, we find no support for such a state.     

Binomial sums, moments and invariant subspaces

The main result of this paper is that if a sequence of complex numbers (a _n)_n≥0 satisfies and % MathType!MTEF!2!1!+- for some integerr≥0, thena _n=0 for alln>r. As an application, we deduce a localized form of a theorem of Allan about nilpotent elements in Banach algebras, and this in turn leads to an invariant-subspace theorem. As a further application, we prove a variant of Carleman's theorem on the unique determination of probability distributions by their moments. The paper concludes with a quantitative form of the main result. Research supported by grants from the Natural Sciences and Engineering Research Council of Canada, the Fonds FCAR of Québec, and the Ministry of Education of Québec (co-opération Québec-France).     

On Diophantine sets over polynomial rings

We prove that the recursively enumerable relations over a polynomial ring , where is the ring of integers in a totally real number field, are exactly the Diophantine relations over .

     

纳米分子筛LTA包裹Ni-Salen配合物为修饰碳糊电极用于电催化氧化肼反应（英文）

采用柔性配体法将Ni-salen配合物包裹在纳米分子筛LTA的超笼中,用来修饰碳糊电极制得Ni(Ⅱ)-Salen A/CPE,并采用循环伏安法、计时电流法和计时库仑法考察了该电极电催化氧化0.1 mol/L Na OH溶液中肼反应性能.首先采用无有机模板剂法合成纳米分子筛LTA,并用各种技术进行了表征.XRD和粒径分析结果分别显示LTA晶体的平均粒径为56.1和72nm.在Ni(Ⅱ)-Salen A/CPE电极氧化还原位上水合肼催化氧化反应电子转移系数为0.64,速率常数为1.03×10~5 cm~3/(mol·s).电催化反应机理研究表明,水合肼氧化反应通过它与Ni~(3+)(Salen)O(OH)反应或直接进行电氧化反应.阳极峰电流与扫描速率的平方根呈线性关系,表明反应受扩散控制,水合肼的扩散系数为1.18×10~(-7)cm~2/s.结果表明,Ni(Ⅱ)-Salen A/CPE对水合肼氧化反应表现出高的电催化活性,这是由于纳米分子筛LTA的多孔结构以及Ni(Ⅱ)-Salen的存在.最后研究了水合肼在碱性溶液中Ni(Ⅱ)-Salen A/CPE电极上的氧化反应机理,发现其为四电子过程,第一个电子转移反应为速率控制步骤,然后是一个三电子过程,产生环境友好的最终产物氮气和水.     

Copper-catalyzed efficient synthesis of 5-arylindazolo[3,2-b]quinazolin-7(5H)-ones from 2-nitrobenzaldehydes

A novel and practical copper-catalyzed approach was developed for the preparation of 5-arylindazolo[3,2-b]quinazolin-7(5H)-ones. The 2-amino-N′-arylbenzohydrazideis easily prepared by a reaction of isatoic anhydride with arylhydrazine. Then, through a condensation/intramolecular cyclization reaction by 2-nitrobenzaldehydes in the present of CuI, the corresponding 5-arylindazolo[3,2-b]quinazolin-7(5H)-ones are produced in good yields.