Preparation and characterization of Al2O3-MgO mixed oxides

A new catalyst system V-Cs-Cu-Tl/TiO₂·SiC for vapor-phase selective oxidation reaction of p-tert-butyltoluene to p-tert-butylbenzaldehyde were studied. It was found that the addition of thallium promoted the reaction. After 365 hours stability test, the V-Cs-Cu-Tl/TiO₂·SiC catalyst still kept excellent result that conversion of p-tert-butyltoluene and the selectivity of p-tert-butylbenzaldehyde reach 10 mol% and 80 mol%. The catalyst was characterized by XRD, TEM, FT-IR and ICP measurements.     

化学和电化学方法合成苯/胺封端苯胺四聚体

利用改进了MacDiarmid氧化偶联方法合成了苯／胺封端的苯胺四聚体，通过对循环伏安曲线的分析，给出二聚体经由电化学氧化－化学偶联成为四聚体的机理，利用基质辅助激光解吸质谱和红外光谱对产物进行了表征。     

Determination of microelement content in the samples from the cycle of intensive poultry breeding

The results of analysis of 15 samples of meat, eggs, feed and water used in the cycle of intensive poultry breeding are given in the paper. Twenty chemical elements such as: Sm, Lu, Eu, Hf, Ce, Yb, Cr, La, Br, Sb, Cs, Sc, Fe, Co, Na, Ta, Tb, Zr, Rb and Zn have been quantitatively determined in all the samples by nondestructive neutron activation analysis. Qualitative determination of K, Ca, Ru and Au was also performed in some samples.     

A One-pot Procedure to Prepare Ethynylferrocene and Iodoethynylferrocene

IntroductionFerrocene-containing compounds have been widely used as important probes to investigate the electron transfer/transport properties of the molecular materials1. Recently, this technique was employed in molectronics research, where the ferrocenes were incorporated on the ends of conjugated molecular wires, and the electron transfer/transport abilities of the molecular wires were conveniently studied by electrochemical method2. Ethynylferrocene and iodoethynylferrocene were two import…     

A note on Jordan derivations of triangular rings

Aequationes mathematicae - In this note we prove that every Jordan derivation on a triangular ring is a derivation. Moreover, we show that, under some conditions, every Jordan derivation on a...     

Neutron activation analysis of biological materials for sub ppm amount of mercury without determining the chemical yield

A simple method for the determination of sub ppm amounts of mercury in various biological materials by neutron activation analysis is described. Irradiated samples were decomposed with H₂SO₄-fuming HNO₃ mixture and mercury selectively isolated by ion exchange chromatography using Dowex 50WX2 [H⁺] and Dowex 1X4 [Br⁻] columns in HBr medium. Finally the activity of¹⁹⁷Hg fixed on an anion exchange resin was measured either with a Ge(Li) or a NaI (Tl) detector. Both the high radiochemical purity of mercury and the practically quantitative recovery were achieved thus eliminating the necessity of determining the chemical yield. The method was used for the determination of mercury in flour, milk, butter, margarine, fish, etc.     

Electron-beam irradiation on poly(propylene carbonate) in the presence of polyfunctional monomers

Poly(propylene carbonate) (PPC) showed predominantly degradation under electron-beam irradiation, accompanied by deterioration of its mechanical performance due to sharp decrease of the molecular weight. Crosslinked PPC was prepared by addition of polyfunctional monomer (PFM) to enhance the mechanical performance of PPC. When 8 wt% of PFM like triallyl isocyanurate (TAIC) was added, crosslinked PPC with a gel fraction of 60.7% was prepared at 50 kGy irradiation dose, which showed a tensile strength at 20 °C of 45.5 MPa, whereas it was only 38.5 MPa for pure PPC. The onset degradation temperature (T_i) and glass transition temperature (T_g) of this crosslinked PPC was 246 °C and 45 °C, respectively, a significant increase related to pure PPC of 211 °C and 36 °C. Therefore, thermal and mechanical performances of PPC could be improved via electron-beam irradiation in the presence of suitable PFM.     

Numerical Solution of Transonic Flow in SE1050 Cascade

The SE1050 cascade is an open test case (QNET network) of plane turbine cascade measured at the IT ASCR wind tunnel. The two regimes with subsonic and supersonic outletMach number were selected for numerical simulation. Several numerical methods have been developed and also several turbulence models have been implemented. Comparison of computed results and experimental data gives us opportunity to discuss main features of transonic flow field in well designed turbine cascade, possibilities of its numerical capturing (grid quality, numerical viscosity, turbulence model, boundary layer transition) and its influence on prediction of energy losses. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

2-local superderivations on a superalgebra Mn(\mathbb C){{\rm M}_{\rm n}({\mathbb C})}

The aim of this paper is to show that every 2-local superderivation on an associative superalgebra M_n(\mathbb C){M_n({\mathbb C})} is a superderivation.