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于永江  徐强  徐秀玮 《中国物理 B》2011,20(12):123402-123402
The N+H2 reaction has attracted a great deal of attention from both the experimental and the theoretical community, and most of the attention has been paid to the first excited state N(2D) atoms in collisions with hydrogen molecules and the scalar properties of the reaction. In this paper, we study the stereo dynamical properties and calculate the reaction cross sections of the N(4S) + H2 (v=0, j=0, 2, 5, 10) → NH(X3Σ-) + H using the quasi-classical trajectory (QCT) method on an accurate NH2 potential energy surface (PES) reported by Poveda and Varandas [Poveda L A and Varandas A J C 2005 Phys. Chem. Chem. Phys. 7 2867], in a collision energy range of 25 kcal·mol-1-140 kcal·mol-1. Results indicate that the reactant rotational excitation and initial collision energy both have a considerable influence on the distributions of the k-j′ correlation, the k-k′-j′ correlation and k-k′ correlation. The differential cross section is found to be sensitive to collision energy.  相似文献   

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We employ the covariant version of a systematic framework of nonequilibrium thermodynamics to clarify the role of entropy in the classical theory of gravitation. An expression for the global entropy is identified naturally from the covariant formulation, and a dual role of the Einstein equation as a fundamental evolution equation and as a thermodynamic equation of state follows immediately. The covariant time integral of the entropy is a more fundamental quantity than the entropy itself. In the absence of matter, the gravitational entropy alone cannot generate any irreversible processes. Some implications for the structure of a quantum theory of gravity are discussed.  相似文献   

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The motion of a particle in a static, spherically symmetric gravitational field is investigated in Euclidean space. The gravitational effects are described as due to a scalar field: To every point in space there is assigned a refractive index deciding the velocity of light in that point. The motion of light in the vacuum is described by the equation of classical optics. An equation of motion for material test particles is then derived by employing the usual Lagrangian formalism. The motion of the planets around the sun is explained, in particular the perihelion motion of Mercury. The present theory fully explains the four classical tests of general relativity in a mathematically far simpler way, and it can be equivalent to the Schwarzschild solution. It is also found that the effect of gravitation depends on the velocity of the particle, becoming repulsive for radial velocities larger thanc/ (c is the velocity of light). This seemingly odd result can also be obtained from the equations of general relativity, as was shown by Cavalleri and Spinelli.  相似文献   

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Based on the new metric theory of gravitation suggested by the author of this article, it gives a possible theoretical interpretation on the famous experiment done by D.R. Long in 1976, i.e. the distance-dependent effect of the gravitational constant in Newton's theory of gravitation.  相似文献   

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A tensorial formalism adapted to the case of XY3Z symmetric tops has been developed. We use the O (3) ⊃ Cv ⊃ C3v group chain. All the coupling coefficients and formulas for the computation of the matrix elements are given for this chain. Such relations are also deduced in C3v group itself.  相似文献   

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In previous papers we showed that certain aesthetic ideas led to a bounded particle. In this paper, we show that a theory based on jk;l i =0,g ij;k =0 withg=0 can also lead to a bounded particle. This theory has the advantage that all tensors constructed fromg ij , jk i , i are treated in a uniform way. Also, we have sixty-four distinct jk i appearing. This was not the case in our previous work.  相似文献   

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In this paper we classify Bianchi type VIII and IX space—times according to their teleparallel Killing vector fields in the teleparallel theory of gravitation by using a direct integration technique. It turns out that the dimensions of the teleparallel Killing vector fields are either 4 or 5. From the above study we have shown that the Killing vector fields for Bianchi type VIII and IX space—times in the context of teleparallel theory are different from that in general relativity.  相似文献   

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张陈俊  王养丽  陈朝康 《物理学报》2018,67(11):113101-113101
利用密度泛函理论的B3LYP方法,在LANL2DZ水平上对碳基混合团簇InC_n~+(n=1—10)进行了系统研究,得到了这个团簇体系的最稳定几何构型以及基态结构的电子态、最低振动频率、总能量、自旋污染期望值、偶极距、转动常数等.计算结果显示:团簇的最稳定结构是In原子位于碳链末端的直线型构型;n为偶数的基态是三重态,除InC~+外,n为奇数的基态是单态.通过对增量结合能和能量二阶差分的计算和分析可以得出,随着团簇尺寸的增加,团簇的稳定性表现出强烈的奇强偶弱振荡规律.电离能的计算结果进一步证实了这种振荡规律的正确性.对系列团簇基态的磁性研究表明,团簇的磁矩随团簇尺寸的增加呈现出明显的奇弱偶强振荡规律.极化率的计算结果显示,极化率张量的平均值及各向异性不变量都随着团簇尺寸的增大而增大.  相似文献   

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R. Aaij  &  nbsp  &  nbsp  et al&  nbsp  &  nbsp   《中国物理C(英文版)》2016,40(1):011001-011001
The product of the Λb0(B0) di erential production cross-section and the branching fraction of the decay Λb0→J/ψpK- (B0→J/ψpK*(892)0) is measured as a function of the beauty hadron transverse momentum, pT, and rapidity, y. The kinematic region of the measurements is pT <20 GeV/c and 2.0< y< 4.5. The measurements use a data sample corresponding to an integrated luminosity of 3fb-1 collected by the LHCb detector in pp collisions at centre-of-mass energies √s= 7 TeV in 2011 and √s= 8 TeV in 2012. Based on previous LHCb results of the fragmentation fraction ratio, fΛb0/fd, the branching fraction of the decay Λb0→J/ψpK- is measured to be
Bb0→J/ψpK-)=(3.17±0.04±0.07±0.34-0.28+0.45)×10-4,
where the rst uncertainty is statistical, the second is systematic, the third is due to the uncertainty on the branching fraction of the decay B0→J/ψpK*(892)0, and the fourth is due to the knowledge of fΛb0/fd. The sum of the asymmetries in the production and decay between Λb0 and Λb0 is also measured as a function of pT and y. The previously published branching fraction of Λb0→J/ψpπ-, relative to that of Λb0→J/ψpK-, is updated. The branching fractions of Λb0→Pc+(→J/ψp)K- are determined.  相似文献   

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