Electrical transport and thermoelectric properties of Ni-doped YCo1−xNixO3(0 ≤ x ≤ 0.07), prepared by using the sol-gel process, are investigated in a temperature range from 100 to 780 K. The results show that with the increase of Ni doping content, the values of DC resistivity of YCo1−xNixO3 decrease, but carrier concentration increases. The temperature dependences of the resistivity for YCo1−xNixO3 are found to follow a relation of ln ρ ∝ 1/T in a low-temperature range (LTR) (T < ∼ 304 K for x = 0; ∼ 230 K < T < ∼ 500 K for x = 0.02, 0.05, and 0.07) and high-temperature range (HTR) (T > ∼ 655 K for all compounds), respectively. The estimated apparent activation energies for conduction Ea1 in LRT and Ea2 in HTR are both found to decrease monotonically with doping content increasing. At very low temperatures (T < ∼230 K), Mott's law is observed for YCo1—xNixO3 (x ≥ 0.02), indicating that considerable localized states form in the heavy doping compounds. Although the Seebeck coefficient of the compound decreases after Ni doping, the power factor of YCo1−xNixO3 is enhanced remarkably in a temperature range from 300 to 740 K, i.e., a 6-fold increase is achieved at 500 K for YCo0.98Ni0.02O3, indicating that the high-temperature thermoelectric property of YCoO3 can be improved by partial substitution of Ni for Co.
The stereodynamic properties of the reaction C (3P) + NO(X2Π) → CN (X2Σ+) + O (3P) in different rotational states of reactant NO are studied theoretically by using the quasiclassical trajectory method on 2A″ and 2A′ potential energy surfaces (PESs) at a collision energy of 0.06 eV. The vector properties in different rotational states on the two surfaces are discussed in detail. The results indicate that the rotational excitation of NO has considerable influence on the stereodynamic property of the reaction occurring on the two surfaces. At the same time, the calculated polarization-dependent differential cross sections (PDDCSs) in different initial rotational states manifest that products are strongly polarized at three scattering angles.
The temperature dependences of electrical resistivity for Sr-substituted compounds Y1-xSrxCoO3 (x=0, 0.01, 0.05, 0.10, 0.15, 0.20), prepared successfully by sol-gel process, are investigated in a temperature range from 20 to 720 K. The results indicate that with the increase of doping content of Sr the resistivity of Y1-xSrxCoO3 decreases remarkably, which is found to be caused by the increase of carrier concentration. In a temperature range below 330 and 260 K for the sample x=0 and 0.01, the relationship of resistivity versus temperature processes exponential relationship lnρ∝1/T, with conduction activation energy 0.2950 and 0.1461 eV for the sample x=0 and 0.01 respectively. Moreover, experiments show that the relationship lnρ∝1/T exists only in high-temperature regime for the heavily doped samples; at low temperatures Mott’s law lnρ∝T-1/4 is observed, indicating that heavy doping produces strong potential, which leads to the formation of considerable localized state. By fitting the experimental data to Mott’s T-1/4 law, the density of localized states N(EF) at Fermi level is estimated, which is found to increase with doping content increasing.
Preliminary inversion results show that the Fernald forward integration method (FFIM) can be used to calculate aerosol backscatter coefficient from airborne atmosphere detecting lidar. But the corresponding theoretical explanations have not been found in relevant papers. In this paper,We use the simulated data based on the ground-based atmosphere detecting radar in Hefei lidar data on February 27, 2008, to quantitatively analyze the above inversion results obtained by the FFIM . Results show that there are three main reasons that the FFIM can be used to calculate aerosol backscatter coefficient when the altitude of lidar calibration points is about 10km. First, the inversion error cannot be infinite and negative results will not appear because the difference batween the denominator items in the Fernald forward integration equation is always greater than zero. Second, inversion error is no more than 0.006 when calibration error is 100%, which is 0.6 percent of the denominator value. Third, Molecule backscatter coefficient is dominant in the calibration item of the Fernald forward integration equation. Big fluctuation range of aerosol backscatter coefficient in the calibration points has little influence on the calibration item value. In general, the atmosphere structure that has a small density in the upper layer but a big density in the lowerlayer, and a high calibration position are two basic reasons for which the FFIM can be applied to the aerosol backscatter coefficient inversion through using airborne atmosphere detecting lidar data.
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