共查询到20条相似文献,搜索用时 31 毫秒
1.
FAN Hong-Yi LOU Sen-Yue 《理论物理通讯》2008,49(3):613-616
We introduce bivariate normal distribution operator for state vector [ψ) and find that its marginal distribution leads to one-dimensional normal distribution corresponding to the measurement probability |λ,v〈x|.ψ〉|^2, where |x〉λ,v is the coordinate-momentum intermediate representation. As a by-product, the one-dimensional normal distribution in statistics can be explained as a Radon transform of two-dimensional Gaussian function. 相似文献
2.
U14Au51 and UAu2 were recently demonstrated the two correct phases stable at room temperature in the U-Au system. Magnetic susceptibility (1.5–300 K) and electrical resistivity (10–800 K) measurements were performed in samples of both phases. Magnetic susceptibility temperature behaviour gives evidences of an antiferromagnetic transition at 23 K in U14Au51, whereas no magnetic order is detected in UAu2. In both compounds, Kondo-like logarithmic behaviour in electrical resistivity temperature trend is found. Effects already observed in U2Zn17 and UAl2 are respectively found in U14Au51 and UAu2. Possible “heavy fermion” properties of these compounds are discussed. 相似文献
3.
为测量流激水下翼型结构的流噪声,提出了一种混响箱测量方法。在重力式水洞中搭建了一套实验测量系统,利用混响箱法测量了水下翼型结构模型的辐射声功率。在此基础上研究了流速及结构参数(厚度、肋、声学覆盖层)对其辐射声功率的影响。结果表明:当流速小于5 m/s时,辐射声功率随流速的6次方增长,符合偶极子的辐射规律;当流速大于5 m/s时,辐射声功率随流速的10土1次方规律增长,不再按偶极子的规律辐射;若对水下翼型结构模型加厚、加环肋及外部敷设黏弹性材料,均可在一定程度上抑制流噪声。此研究方法可对水下复杂结构的辐射声功率测量及结构优化设计提供一定的参考。 相似文献
4.
T. Endstra G. J. Nieuwenhuys J. A. Mydosh K. H. J. Buschow 《Journal of magnetism and magnetic materials》1990,89(3):L273-L276
We have prepared and studied a new series of isostructural U3T3X4-compounds with T = Co, Ni, Cu for X = Sb and T = Ni for X = Sn. Ferromagnetism is found for U3Co3Sb4 and U3Cu3Sb4 below 10 and 88 K, respectively. In contrast, no magnetic order was observed down to 1.7 K for the semiconductor U3Ni3Sb4 and the “moderately” heavy-fermion system U3Ni3Sb4. 相似文献
5.
构造了由普通材料A(SiO2)和电单负材料B组成的(AB)N(BA)N型一维光子晶体.数值计算表明原禁带的1907.3 nm处出现了一个十分尖锐的隧穿模. 入射角增加,该隧穿模的透射率和半峰全宽度均保持不变,但位置发生蓝移, 入射角在15°-65°的区间内,移动率的绝对值 |dλ/dθ| 较大.当B介质的磁导率μB 从5增加到10时,只是隧穿模的位置发生了红移. 介质的几何厚度增加时,隧穿模的透射率不变,但其位置红移明显,半峰全宽略有增加. 相似文献
6.
WANG Jing & ZENG Jinyan Department of Physics Tsinghua University Beijing China School of Physics Peking University Beijing China 《中国科学G辑(英文版)》2004,47(6)
1 Introduction Though one-dimensional (1D) systems may clearly exhibit many features of quan-tum mechanics, systems with many degrees of freedom provide more opportunities tostudy many other important features, e.g. the degeneracy of energy eigenstates, whichneed a complete set of commuting observables to characterize an energy eigenstate. Inparticular, two-dimensional (2D) systems with two spatial degrees of freedom may ex-hibit symmetries not present in 1D systems, e.g. the rotational symme… 相似文献
7.
The stereodynamics and reaction mechanism of the H′(^2S) + NH (X^3∑^-) → N(^4S) + H2 reaction are thoroughly studied at collision energies in the 0.1 eV-1.0 eV range using the quasiclassical trajectory (QCT) on the ground 4A″ potential energy surface (PES). The distributions of vector correlations between products and reagents P(φr), P(φr) and P(φr,φr) are presented and discussed. The results indicate that product rotational angular momentum j′ is not only aligned, but also oriented along the direction perpendicular to the scattering plane; further, the product H2 presents different rotational polarization behaviors for different collision energies. Furthermore, four polarization-dependent differential cross sections (PDDCSs) of the product He are also calculated at different collision energies. The reaction mechanism is analyzed based on the stereodynamics properties. It is found that the abstraction mechanism is appropriate for the title reaction. 相似文献
8.
The energy spectra of three-axial ferromagnets like U3P4 and ferrimagnets like U3Sb4 are presented and their properties are discussed. In case of U3Sb4 we find an interesting example of a magnetic structure which, due to the single-ion anisotropy, is unstable in the spin wave approximation. The k2 dependence of magnon energies requires re-examination of the temperature dependence of the magnetisation and of the specific heat. 相似文献
9.
FAN Hong-Yi 《理论物理通讯》2006,45(5):845-848
For the superposition field
a1†+a2†
of two light modes we introduce an appropriate diagonal
P-representation which is constructed on the common eigenvectors |z,x〉of
(X1-X2) and
a1+a2,
where Xi=(ai+
ai†)/√(2),
[ai,ai†] =δij. It is remarkable that |z,x〉make up a new quantum mechanical representation. 相似文献
10.
By employing the bipartite entangled state representation and the technique of integration within an ordered product of operators, the classical complex wavelet transform of a complex signal function can be recast to a matrix element of the squeezing-displacing operator U 2(μ, σ) between the mother wavelet vector 〈ψ| and the two-mode quantum state vector |f〉 to be transformed. 〈ψ|U 2(μ, σ)|f〉 can be considered as the spectrum for analyzing the two-mode quantum state |f〉. In this way, for some typical two-mode quantum states, such as two-mode coherent state and two-mode Fock state, we derive the complex wavelet transform spectrum and carry out the numerical calculation. This kind of wavelet-transform spectrum can be used to recognize quantum states. 相似文献
11.
运用准经典轨线方法(QCT), 基于Abrahamsson等构造的4A"势能面(Abrahamsson E Andersson S, Nyman G, Markovic N 2008 Phys. Chem. Chem. Phys. 10 4400), 在碰撞能为0.06 eV时, 对C(3P)+NO(X2Π )→CO(X1Σ+)+N(4S)反应立体动力学性质进行了理论研究. 在考虑反应物NO转动和振动激发的条件下, 计算了质心坐标系下k-j'矢量(k与j'分别为反应物速度与产物角动量)相关的P(θr)分布和k-k'-j'矢量(k'为产物相对速度)相关的P(φr)分布. 此外还计算了该反应的三个极化微分截面(2π/σ)(dσ00/dωt), (2π/σ)(dσ20/dωt)以及(2π/σ)(dσ22+dωt). 计算结果表明转动和振动激发对产物取向影响较大而对定向影响较小; 对于三个极化微分截面, 转动激发的影响不大, 而振动激发的影响则较大. 相似文献
12.
Quasi-classical trajectory study of the isotope effect on the stereodynamics in the reaction H(2S)+CH(X2Π; v=0, j=1)→C(1D)+H2(X1Σg+)
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The isotope effect on the stereodynamic properties in the title reaction is investigated by a quasi-classical trajectory (QCT) method on the 11A' potential energy surface at a collision energy of 23.06 kcal/mol. The angular distributions P(θr), P(ør), P(θr, ør), and the polarization-dependent generalized differential cross sections are calculated, which demonstrate the observable influences on the rotational polarization of the product by the isotopic substitution of H with D. 相似文献
13.
Effects of collision energy and rotational quantum number on stereodynamics of the reactions:H(~2S)+NH(v=0,j=0,2,5,10)→N(~4S)+H_2
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The stereodynamical properties of H(~2S) + NH(v = 0,j = 0,2,5,10)→N(~4S) + H_2 reactions are studied in this paper by using the quasi-classical trajectory(QCT) method with different collision energies on the double many-body expansion(DMBE) potential energy surface(PES)(Poveda L A and Varandas A J C 2005 Phys.Chem.Chem.Phys.7 2867).In a range of collision energy from 2 to 20 kcal/mol,the vibrational rotational quantum numbers of the NH molecules are specifically investigated on v = 0 and j = 0,2,5,10 respectively.The distributions of P(θ_r),P(φ_r),P(θ_r,φ_r),(2π/σ)(dσ_(00)/dω_t)differential cross-section(DCSs) and integral cross-sections(ICSs) are calculated.The ICSs,computed for collision energies from 2 kcal/mol to 20 kcal/mol,for the ground state are in good agreement with the cited data.The results show that the reagent rotational quantum number and initial collision energy both have a significant effect on the distributions of the k-j',the k-k'-j',and the k-k' correlations.In addition,the DCS is found to be susceptible to collision energy,but it is not significantly affected by the rotational excitation of reagent. 相似文献
14.
色散方程的一类具任意稳定性的显格式 总被引:4,自引:0,他引:4
本文对色散方程ur=auxxx构造了一类中间层包含四个结点,带两个参数m和θ的三层显式差分格式。当m和θ满足一定的关系时,其稳定性条件为|γ|≤(m+1)/(4(m-1))(|m|>1),从而当取m充分接近1时,可得到任意大的稳定性条件,并且保持截断误差阶不变。数值例子验证了理论分析的结果。 相似文献
15.
The comnactification of the D=10 E8 × E8 field theory limit of superstring to the D=4 SU3 × SU2 × U1 standard model is investigated by means of the scheme developed by Manton, Forgacs and Chapline. 相似文献
16.
L. G. Mann
S. D. Bloom
《Nuclear Physics A》1970,140(3):598-608β-γ(CP) correlation measurements have been carried out on the
sequence in the decay of the ground state of 49Ca to the (presumed) anti-analogue state at 3.105 MeV excitation in 49Sc. An asymmetry parameter of A = −0.132 ± 0.017 was obtained, making any spin-parity assignment other than
very unlikely for the 3.105 MeV state. The deduced Fermi matrix element for the decay is |Mv| = |1.4 ± 9.7| × 10−3, which leads to an isospin impurity (
) corresponding to the mixing of the analogue state (at 11.6 MeV) and the 3.105 MeV state of ||2 1.6 × 10−5. This leads in turn to an effective Coulomb matrix element of |Hc| = |3.9 ± 27.4| keV, a low value compared to the value of 100 keV obtained from a theoretical estimate based on simple shell-model wave functions for the
single-particle states involved. 相似文献
17.
In this paper the lattice current-current propagator is calcdlated and the influence of coset pure gauge fields of an abelian chiral group G=U1×U15 on confinement properties of a quark system is discussed by virtue of the Wilson's criterion in lattice gauge theory. When subgroup H is U1, the coset pure gauge fields only contribute a perimeter law factor to the current current propagator which has no influence on confinement properties of the system. When subgroup H is Us, the coset puregauge fields have no influence on wnfinement properties of the system either. 相似文献
18.
The vibration states of transition molecule S2O,
including both bending and stretching vibrations, are studied in the
framework of dynamical symmetry groups U1(4)\otimes
U2(4). We
get all the vibration spectra of
S2O by fitting 22 spectra data with 10
parameters. The fitting rms of the Hamiltonian is
2.12 cm-1. With the parameters and Lie
algebraic theory, we give the analytical expression of the potential energy
surface, which helps us to calculate the dissociation energy and force
constants of S2O in the electronic ground state. 相似文献
19.
By virtue of the Weyl correspondence and based on the the technique of integration within an ordered product of
operators, we show under what condition the superoperator's Kraus
representation
ρˊ=∑μ
AμρAμ† can be deformed as
ρˊ=(1/π)∫d2αB(α)D(α)ρD†(α),
where D(α) is the displacement operator, B(α) is a probability density related to the classical Weyl correspondence of Aμ. An alternate discussion by using the entangled state representation and through a quantum teleportation process is also presented. 相似文献