Influence of the conditions of manufacture of nanomeric zirconium dioxide,stabilized with yttrium oxide,on its catalytic properties in the oxidation of CO

The morphological and catalytic properties of samples of nanomeric zirconium dioxide, stabilized with yttrium oxide, manufactured via the effect of a UHF field during the process of drying precipitated zirconium hydroxide and calcination at temperatures from 300 to 1000 °C, were studied. It was shown that the highest activity in the oxidation of CO occurred with 40 nm particles of zirconium dioxide prepared at 1000 °C. __________ Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 43, No. 2, pp. 96–101, March–April, 2007.     

Spin density distributions in radical anions of heterocyclic amine N-oxides

The unrestricted Hartree-Fock (UHF) method of Snyder and Amos is used to calculate, in the -electron approximation, the spin density distributions in radical anions of heterocyclic amine N-oxides. The computed spin densities are observed to be in good agreement with the experimental values. The computed spin density distribution of the radical anion of pyridine N-oxide is consistent with the greater susceptibility of pyridine N-oxide relative to pyridine to electrophilic nitration. Also, the calculations are consistent with the lower basicity of the N-oxides relative to the parent bases.     

Covalent-ionic nature of the potential energy surface of the Li-CO2 complex

Unrestricted Hartree-Fock calculations with large basis sets, including d-functions, and the estimation of the correlation energy, show that the potential energy surface for the Li-CO₂ complex is built from the crossing of two states, each of them corresponding to a different electron arrangement. One has a strong ionic character and the other is of van der Waals type. Each portion of the energy surface presents a minimum, which is stable in respect to the dissociation limit.     

一种便携式GIS局放检测装置的设计

为解决现有的GIS绝缘检测装置存在的体积大、不易实现在线检测、受周围环境影响,测量精度不高等问题,笔者采用时差计算法,对局部放电源进行定位,并通过由高通滤波器、宽带放大器、检波器、电/光变换器和光/电变换器组成的两个通道,分别接收和处理两个来自不同位置检测到的局放信号,从而使检测精度大大提高。实验结果表明,该系统具有重量轻、携带方便、灵敏度高,可实现局放源定位等特点。     

UHF代数中的有限CSL代数的闭Lie理想

本文描述了UHF代数B中的有限CSL代数Alg(M)的闭Lie理想。证明了Alg(M)中的闭子空间L是Alg(M)的闭Lie理想当且仅当存在Alg(M)的闭结合理想J和Alg(M)的对角部分的中心的子空间E使得(J)0■L■J+E,其中(J)0是J中迹为0的元素的集合。     

异自旋中心有机铁磁体分子设计

采用量子化学从头算ＵＨＦ方法对系列异自旋三自由基体系的基态自旋耦合规律进行研究，并对组成不同的异自旋（ｈｉｅｔｅｒｏ ｓｐｉｎ）三自由基进行了系统的比较，为新型有机磁性材料的实验合成提供了理论依据。     

UHF机械调谐器调谐电容片形的程序设计

采用传输线理论可以计算机械式UHF调谐器对应不同频率点的调谐电容量。在进行满足直线频率关系的调谐电容片形设计时,应当求出调谐电容量C_Τ与旋转角θ的显式函数关系。但对于分布参数的电路,这有一定的困难。本文采用数值计算方法完成了具有良好直线频率跟踪特性的调谐电容片形的设计,并由计算机自动绘出了片形。     

Detection and analysis of radio pulses from extensive air showers

Radio pulses from extensive air showers (EAS) at 30, 44, and 60 MHz frequencies have been studied, using wide band broad-side arrays of half-wave dipole antenna systems. The experimental results support the theoretical prediction that the field strength of radio emission depends on the shower size. An asymmetry has been noticed in the pulse height distributions of radio pulses detected by North-South and East-West directed arrays. These observations are in agreement with the theory that the charge separation mechanism is predominant in generating radio pulses from EAS and radio emission is polarised in the East-West direction. Experimental data are compared with those of earlier workers.