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961.
本文从 H_O_2的电极反应的氧化反应和还原反应半反应入手,结合热办学原理和偶合反应原理,运用自由能变与电极电势的关系从理论上解释了 H_2O_2在酸碱性介质中氧化还原性存在极大差异的原因. 相似文献
962.
Mössbauer spectra of Co x Mn1?x Fe2O4 and Ni x Mn1?x Fe2O4 ferrites withx values ranging from 0·1 to 0·8 in steps of 0·1 have been recorded at room temperature. All spectra exhibit well-defined Zeeman hyperfine patterns. It has been observed that hyperfine field at Fe3+ nucleus increases more rapidly by nickel substitution than by cobalt substitution. This has been explained in terms of exchange interactions and cation distribution in the spinels. Hyperfine fields, isomer shifts and quadrupole splittings have been determined. 相似文献
963.
The interaction energies (X1) between the polymers polypropylene, poly(vinylidene chloride), sulphonyldiphenyl formaldehyde resin and poly(vinyl pyrrolidone) and the solvents toluene, ethylbenzene, isopropylbenzene, ortho, meta, and para-xylene are determined by gas chromatography. As shown in earlier publications, this technique for the determination of X1, can be extended to similar systems of theoretical as well as of practical importance, although the selection of the present systems was primarly made on the fact that these systems are of industrial interest and have not so far been investigated by gas-liquid chromatography. The studies were carried out at two temperatures and the results obtained show a decrease of X1 with an increase of temperature. 相似文献
964.
ZHENG Jianping LU Fengxiang YU Chunmei & TANG HuayunFaculty of Earth Sciences China University of Geosciences Wuhan China 《科学通报(英文版)》2004,49(3):277-285
Backscattered electron images, in situ Hf isotopes, U-Pb ages and trace elements of zircons in a banded granulite xenolith from Hannuoba basalt have been studied. The results show that the banded granulite is a sample derived from the early lower crust of the North China craton. It is difficult to explain the petrogenesis of the xenolith with a single process. Abundant information on several processes, however, is contained in the granulite. These processes in-clude the addition of mantle material, crustal remelting, metamorphic differentiation and the delamination of early lower crust. About 80% of zircons studied yield ages of 1842 ±40 Ma, except few ages of 3097-2824 Ma and 2489-2447 Ma. The zircons with ages older than 2447 Ma have high εHf (up to +18.3) and high Hf model age (2.5-2.6 Ga), indicating that the primitive materials of the granulite were derived mainly from a depleted mantle source in late Archean. Most εhf of the zircons with early Proterozoic U-Pb age vary around zero, but two have 相似文献
965.
YUANQunhui LUJun WANLijun BAIChunli 《科学通报(英文版)》2004,49(24):2590-2593
Self-assembled structures of 3,4,5-tris-dodecy-loxy benzoic acid methyl ester (E12), 3,4,5-tris-tetradecy-loxy-benzoic acid methyl ester (E14) and their mixture (E12/E14) have been studied on HOPG by scanning tunneling microscopy (STM). Dimer-like patterns induced by dipole-dipole interaction are observed in E12 and E14 monolayers. The molecules form close-packed rows and interdigitate with the alkyl chains in adjacent molecules. The structural differences are proposed to be from the different length of substituted alkyl chains. Owing to similar adsorption energy, phase separation is observed in the E12 and E14 mixed adlayer with different domains. 相似文献
966.
J. N. Spencer Eric S. Holmboe Daniel W. Firth Mindy R. Kirshenbaum 《Journal of solution chemistry》1981,10(10):745-756
Enthalpies of solution have been used to calculate transfer enthalpies for phenol, pyridine, and DMSO between the solvent cyclohexane and the solvents CCl4, benzene, and CHCl3. By use of model compounds, enthalpies due to interactions with phenol, pyridine, and DMSO have been determined. These enthalpies are used to calculate the effect of solvation relative to cyclohexane on hydrogen bonded complexes in CCl4 and benzene solvents. Correlations with enthalpies due to interactions and frequency shifts for the hydroxyl stretch in these solvents have also been made. 相似文献
967.
968.
制备了[(Fe/Pt/Fe)/Ag]n多层膜,研究了不同温度退火后的微结构和磁特性.实验结果表明温度高于400℃退火后,样品开始形成L10相的FePt纳米颗粒与Ag基体的复合结构.ΔM曲线的测量表明FePt颗粒之间不存在交换作用,非常清楚地说明非磁基体Ag有效地隔离了FePt磁性颗粒.有序相的低温合成可能和多层膜结构所造成的界面扩散以及Ag层引入的界面缺陷有关,同时,Ag原子较强的迁移性以及FePt与Ag之间表面自由能的显著差异,使FePt纳米颗粒被Ag隔离.
关键词:
L10相
FePt
交换作用 相似文献
969.
I. Haysak Yu. Fekete V. Morokhovych S. Chalupka M. Salak 《Czechoslovak Journal of Physics》2005,55(5):541-554
Based on the numeric solution of a system of coupled channels for vector mesons (S-and D-waves mixing)and for tensor mesons (P- and F- waves mixing) mass spectrum and wave functions of a family of vector mesons q
in triplet states a e obtained. The calculations are performed using a well-known Cornell potential with a mixed Lorentz- structure of the confinement term. The spin-dependent part of the potential is taken from the Breit-Fermi approach.The effect of irregular terms of the potential is considered within the framework of the perturbation theory and/or of the configuration interaction approach, modified for a system of coupled equations. It is shown that even a small integral contribution of the D-wave to the total wave function of q
system is very impotant for the calculation of certain characteristics of the meson states. 相似文献
970.
For two types of stochastic particle systems in we show non-explosion in finite time by proving that their respective generators are L1(μ)-unique, where μ is their respective invariant (in these cases even symmetrizing) measure. We also prove the much harder L2(μ)-uniqueness in both models. 相似文献