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991.
采用内收缩多参考组态相互作用(MRCI)方法, 结合价态范围内的最大相关一致基aug-cc-pV6Z, 计算了SiN自由基X2∑+, A2Π 和B2∑+电子态的势能曲线. 采用Davidson修正来避免由于MRCI方法本身的大小一致性缺陷产生的误差. 为了提高计算精度, 进一步考虑了相对论修正和核价相关修正对势能曲线的影响. 本文的相对论修正是利用二阶Douglas-Kroll 哈密顿近似在cc-pV5Z基组水平进行的; 同时核价相关修正是在cc-pCV5Z基组水平进行的. 对这些势能曲线进行拟合, 得到各种水平下三个电子态的光谱常数(Te, Re, ωe, ωexe, αe和Be), 并详细分析了Davidson修正、相对论修正和核价相关修正对光谱常数的影响. 与其他理论结果和实验数据进行比较, 可知本文的结果更精确、更完整. 相似文献
992.
C.M. da Silva F.P. Livi E. Panarotto A.A. Gomes 《Journal of magnetism and magnetic materials》1987,70(1-3):52-54
An extension of the usual tight binding CPA to include local d-p hybridization induced by sp impurities (Al or Si) is proposed. Coupled self-consistency equations for the d and p effective medium self-energies are established. An application to Zr(Fe1−xAlx)2 pseudobinary is presented. 相似文献
993.
K. Goeke J. Ossmann P. Schweitzer A. Silva 《The European Physical Journal A - Hadrons and Nuclei》2006,27(1):77-90
The dependence of the nucleon mass on the mass of the pion is studied in the framework of the chiral quark-soliton model.
A remarkable agreement is observed with lattice data from recent full dynamical simulations. The possibility and limitations
to use the results from the chiral quark soliton model as a guideline for the chiral extrapolation of lattice data are discussed. 相似文献
994.
995.
C. G. Amorim A. N. Araújo M. C. B. S. M. Montenegro V. L. Silva 《Electroanalysis》2007,19(21):2227-2233
Amantadine potentiometric detectors were developed, evaluated and incorporated in a SIA‐LOV manifold in order to accomplish the control of pharmaceutical formulations and urine. The electrodes incorporate α‐cyclodextrin as ionophore, dibutyl phthalate or 2‐fluorophenyl 2‐nitrophenyl ether as plasticizers and potassium tetrakis[3,5‐bis‐(trifluoromethyl)phenyl]borate (KTFPB) as cationic additive. The slope increased from 61.2 to 63.8 mV decade?1 and the practical limit of detection from 2.6×10?6 mol L?1 to 2.5×10?5 mol L?1 when the plasticizer was changed from 2‐fluorophenyl 2‐nitrophenyl ether to dibutyl phthalate. When incorporated in the flow‐manifold the membranes composed by dibutyl phthalate or with 2‐fluorophenyl 2‐nitrophenyl ether presented slopes and a practical limit of detection of 69.8 mV decade?1 and 1.5×10?4 mol L?1 or 73.7 mV decade?1 and 5.4×10?5 mol L?1, respectively. The electrode presented stable responses for over a year, and were highly selective concerning the representative species of the two sample matrices assayed as interferents. Comparison of obtained results with those provided by reference methods and recovery assays, revealed adequate accuracy for control assays. 相似文献
996.
A. M. Rodriguez H. Saitovitch P. R. J. Silva J. Weberszpil J. C. Fernandes M. A. Continentino 《Hyperfine Interactions》1993,79(1-4):937-941
We report time differential perturbed angular correlation (TDPAC) measurements above and below the Curie temperature of the ferromagnetic semiconductor (Ag, In)/CdCr2Se4. The TDPAC spectra for the Ag and In dopants have profound differences which we attribute to distinct site occupations of these impurities in the spinel structure. 相似文献
997.
The use of polymers reinforced with fiberglass is becoming more and more common in the switches for household industries. These compounds perform a good tension resistance to the impact and the humidity absorption being used at the present time and also are in the automobile industry in parts underneath the hood, especially in the radiator frames. The aim of this work is to study the effect of ionizing radiation on the properties of polyamide 6 with fiberglass reinforcement and undergone to different irradiation doses. Samples were prepared and irradiated on JOB 188 accelerator with an electron beam energy of 1.5 MeV in air with different doses and a dose rate of 27.99 kGy/h. Afterward, the properties of the non-irradiated and irradiated polyamide 6 with fiberglass reinforcement were evaluated. 相似文献
998.
We characterize the eigenvalues of [X,A]=XA-AX, where A is an n by n fixed matrix and X runs over the set of the matrices of the same size. 相似文献
999.
Q. Liu B. Poumellec C. Haut D. Dragoe R. Blum G. Girard J.-E. Bourée A. Kudlinski Y. Quiquempois G. Blaise 《Applied Physics A: Materials Science & Processing》2005,81(6):1213-1219
Amorphous N- or Ge-doped H:SiO2 films deposited on silica by the matrix distributed electron cyclotron resonance-PECVD method were irradiated by an electron-beam with different doses in order to pole the material and induce second harmonic generation (SHG). SHG was measured using the Maker-fringe method. When irradiated at an acceleration voltage of 25 kV, an incident current of 5 nA during 480 s, the N-doped H:SiO2 films exhibited a maximum second harmonic signal in the order of 0.003 pm/V, but when irradiated with an acceleration voltage of 30 kV, at 5 nA during 240 s, the films exhibited a maximum second harmonic signal of 0.006 pm/V. With a smaller current of 0.5 nA during 25 s and 25 kV acceleration voltage, the Ge-doped H:SiO2 films (3.8 at. % Ge) showed a maximum second-order nonlinearity of 0.0005 pm/V. But an H:SiO2 films with a smaller Ge content (1.0 at. % Ge), showed a large SHG: d33=0.09 pm/V when irradiated at 25 kV, 0.5 nA during 15 s. PACS 78.66.J; 42.65.K; 68.60.D 相似文献
1000.
regulation of the muscle length and the arm of muscular force when the hip was at standard anatomic attitude and in the whole distance range with exercise.Result enunciation: In regard to the machine axes of lower extr 相似文献