Multi-Type Directed Scale-Free Percolation

In this paper,we study a long-range percolation model on the lattice Z d with multi-type vertices and directed edges.Each vertex x ∈ Z d is independently assigned a non-negative weight Wx and a type ψx,where(Wx) x∈Z d are i.i.d.random variables,and(ψx) x∈Z d are also i.i.d.Conditionally on weights and types,and given λ,α 0,the edges are independent and the probability that there is a directed edge from x to y is given by pxy = 1 exp(λφψ x ψ y WxWy /| x-y | α),where φij 's are entries from a type matrix Φ.We show that,when the tail of the distribution of Wx is regularly varying with exponent τ-1,the tails of the out/in-degree distributions are both regularly varying with exponent γ = α(τ-1) /d.We formulate conditions under which there exist critical values λ WCC c ∈(0,∞) and λ SCC c ∈(0,∞) such that an infinite weak component and an infinite strong component emerge,respectively,when λ exceeds them.A phase transition is established for the shortest path lengths of directed and undirected edges in the infinite component at the point γ = 2,where the out/in-degrees switch from having finite to infinite variances.The random graph model studied here features some structures of multi-type vertices and directed edges which appear naturally in many real-world networks,such as the SNS networks and computer communication networks.     

一个新的自由能函数对介电高弹薄膜的多组等双轴预拉伸下力电耦合实验的预测

当介电高弹聚合物薄膜被施以面内等双轴预拉伸后, 受到厚度方向的电压作用时, 薄膜在力场和电场共同作用下产生大变形. 电场采用Maxwell应力分析, 力场采用橡胶弹性模型分析. 拟合这类变形的常用橡胶弹性模型主要有Neo-Hookean, Arruda-Boyce, Gent等模型. 这些模型对实验数据的定量拟合存在不同程度的偏差. 通过对实验数据的分析, 结合数学方法, 提出了一个新的自由能函数模型. 通过该模型对VHB4905介电高弹聚合物薄膜的多组等双轴预拉伸电力耦合实验进行拟合, 并以Neo-Hookean, Gent模型作为对照, 结果与实验数据拟合很好, 比对照模型的偏差明显缩小.     

THEORETICAL INVESTIGATION OF THE ISOSPIN VIOLATING HADRONIC TRANSITIONS Ψ'→Ψ(11P1)+π° AND T"→T(11P1)+π°

The isospin violating processes Ψ'→Ψ(1¹P₁)+π° and T"→T(1¹P₁)+π° are investigated in the framework of the multipole expansion in quantum chromodynamics. Using the rate of Ψ'→Ψ+π° as an input to determine the isospin violating vertex, we obtain the following branching ratios for the processes BR(Ψ'→Ψ(1¹P₁)+π°)～10^-6-10^-5, BR(T"→T(1¹P₁)+π°)～10^-5-10^-3 for M₁1_p1=1/9(5M₁3_p2+3M₁3_p1+M₁3_p0). These are too small to be detected in the present experiments.     

THE CONVERSION OF GLUONS INTO QUARKS AND THE MULTIQUARK STATES

The rate for the conversion of the gluon into a color octet quark pair which subsequently forms a multiquark state with another quark pair or a gluon is discussed. The static potential in a [(QQ)₈(qq)_8,1] state where Q=c,b and q=u, d is studied in the MIT bag model. It is shown that the repulsive Coulomb force between Q and Q is dominant at small QQ separations, which would significantly suppress the QQ wave function at the origin. For the charm quark (Q=c) the ratio of |Ψ(O)|² for the ordinary (QQ)₁ to that for the(QQ)₈ in the [(QQ)₈(qq)_8,1] state is estinated to be 2-5. Therefore the assumption |Ψ₈(O)|²=|Ψ₁(O)|² would lead to an overestimation for the rate of g*→QQ and it is necessary to take the suppression effect of the repulsive Coulomb force into consideration.     

A New Exponential Gravity

We propose a new exponential f（R） gravity model with f（R） = （R - λc） e^λ（c/R）n and n 〉 3, λ ≥ 1, c 〉 0 to explain late-time acceleration of the universe. At the high curvature region, the model behaves like the A CDM model. In the asymptotic future, it reaches a stable de-Sitter spaeetime. It is a cosmologically viable model and can evade the local gravity constraints easily. This model shares many features with other f（R） dark energy models like Hu-Sawicki model and ExponentiM gravity model. In it the dark energy equation of state is of an oscillating form and can cross phantom divide line ωde = -1. In particular, in the parameter range 3 〈 n ≤ 4, λ ～ 1, the model is most distinguishable from other models. For instance, when n = 4, λ = 1, the dark energy equation of state will cross -1 in the earlier future and has a stronger oscillating form than the other models, the dark energy density in asymptotical future is smaller than the one in the high curvature region. This new model can evade the local gravity tests easily when n 〉 3 and λ 〉 1.     

THE LINEAR ELIASHBERG EQUATION

Fn the present paper, the linear Eliashberg equation is converted into a new integral equation and from it, the following T_C formula is derived analytically in the weak coupling limit:T_c=28/πωlog·(πlog/π_c)μ^*/λ^*-μ^* exp{-1+λ/λ-μ^*}, where In γ=C=0.5772 is the Eater constant.     

NOTE ON A MCMILLAN-LIKE Tc FORMULA

In this letter, we present an analysis to understand why the McMillan-like T_c fornula: T_c=1.134ωlog(1-1.02μ^*+0.476λ)exp{-1+1.604λ/λ-μ^*(1+0.604μ)}, proposed in a previous paper by the authcrs,applies to crystalline superconductors satisfactorily but Iess satisfactorily to non-crystalline ones.     

Morse Potential in the Momentum Representation

The momentum representation of the Morse potential is presented analytically by hypergeometric function. The properties with respect to the momentum p and potential parameter β are studied. Note that |Ψ(p)| is a nodeless function and the mutual orthogonality of functions is ensured by the phase functions arg[Ψ(p)]. It is interesting to see that the |Ψ(p)| is symmetric with respect to the axis p=0 and the number of wave crest of |Ψ(p)| is equal to n+1. We also study the variation of |Ψ(p)| with respect to β. The amplitude of |Ψ(p)| first increases with the quantum number n and then deceases. Finally, we notice that the discontinuity in phase occurs at some points of the momentum p and the position and momentum probability densities are symmetric with respect to their arguments.     

kiow.to Search for 'p1 State of CC at BEPC-The Electromagnetic Transition Ψ' -+Ψ('p1) + 2Y1

Decay rate of the process Ψ'→Ψ(¹P₁)+2γ is calculated with all possible intermediate states included in the context of potential model. Out calculation shows that the branching ratio for this channel is about 10^-5.For a total production of 2×10Ψ' particles, it is possible to find out Ψ' (¹P₁) at BEPC through searching for 3γ signals.     

B_s → f_0 (980) Transition Form Factors Within the k_T Factorization Approach

In the paper, we apply the kT factorization approach to deal with the Bs → f0 (980) transition form factors in the large recoil regions, i.e. the small q 2 regions. For the purpose, we adopt the B-meson wave-functions ΨB , ΨB and δ that include the three-Fock states contributions to do our discussion. Although the scalar meson f0 (980) is widely perceived as the 4-quark bound state (scenario 2), but the distribution amplitudes of 4-quark states are still unknown to us, so we adopt 2-quark model (scenario 1) for scalar meson f0 (980) in our discussion. By varying the B-meson wave-function parameters within their reasonable regions, we obtain F0(0) = F+(0) = 0.20 ± 0.02, FT(0) = 0.24 ± 0.02. Our present results for these form factors are consistent with the light-cone sum rule results obtained in the literature.     

白光LED用蓝绿色荧光粉Sr1-xBax Al2O4:Eu2+的发光性质

采用高温固相法在还原气氛中合成Sr1-xBaxAl2 O4:Eu2+荧光材料.XRD显示,当钡掺杂量x＜0.4时,对应样品主要为单斜SrAl2 O4晶体结构;当x≥0.4时,对应样品主要为简单六方BaAl2 O4晶体结构.在360nn激发下,样品的发射光谱随x的增加由单一的绿光发射(λmax=516nm)逐渐转变为蓝绿...     

基于荧光分析法和APTLD相结合的多环芳烃的检测

为准确进行浓度检测,用Savitzky-Golay(SG)多项式曲面平滑法去除三维荧光光谱数据的冗余信息,分别采用平行因子法(PARAFAC)算法和交替惩罚三线性分解(APTLD)算法对光谱数据进行分解。设计多环芳烃类污染物的检测实验,分析了芴(FLU)、苊(ANA)及两者混合溶液的荧光光谱特性。FLU溶液在λ_(ex)/λ_(em)=302/322 nm处存在一个明显的荧光峰,并且存在连续侧峰。ANA溶液存在两个荧光峰,分别为λ_(ex)/λ_(em)=290/322 nm和λ_(ex)/λ_(em)=290/336 nm。在激发波长200～370 nm扫描范围和发射波长240～390 nm扫描范围内,FLU和ANA荧光光谱重叠严重。结果表明,两种算法均能分辨出FLU和ANA,并取得了很高的回收率,但APTLD算法的检测效果更好。     

Absolute spectral distribution of soft X-ray emission from laserproduced gold plasma

Quantitative measurement of spectral distribution of soft X-ray emission from laser produced plasmas and estimation of X-ray conversion efficiency are reported. The X-ray emission from planar gold target irradiated by an Nd:glass laser was recorded using a high resolution transmission grating spectrograph. Spectral distribution of X-ray intensity was derived using calibrated film data and a deconvolution procedure to account for contribution of higher diffraction orders. Results of conversion efficiency per unit solid angle, at a laser intensity of ~4×10¹² W/cm² (λ_L = 1.054 μm), for 10< λ <80 Å and in the water window spectral region (23< λ< 44 Å) are presented. A three-fold increase in conversion efficiency was observed for second harmonic laser irradiation (λ_L = 0.527 μm) at an intensity of 8×10¹² W/cm²     

Theoretical Calculation of Drag Component of Tensor M in Quantizing Magnetic Field

All the previous homogeneous theories result in M_ΧΧ = 0 which are at variance with the experimental data. It is for this reason, previous theories have consistently used experimental value of M_ΧΧ in calculating thermopower tensor S. The inhomogeneous and non-equilibrium formalism proposed by Dyakin et al. was generalized to including both transverse and longitudinal modes of electron-phonon interaction and considering the broadening of the Landau level. The resulting formula gives theoretical values of M_ΧΧ for GaAs/AlGaAs heterojunctions which are in accord with experimental ,data at oscillation phases but (λ_p/)^l/2 times smaller than experimental data for T = 1.275 K, 2.937 K, 5.005 K and C = 0.20 where λ_p and are the phonon mean free path and effective thickness of the heterojunctions. By means of the semi-empirical formula of MzZ with extra factor (λ_p/)^l/2 in, phonon drag magnetothermopower can be calculated from theoretical values of M_yΧ and M_ΧΧ.     

Linearly-Independent Quantum States Can Be Cloned by a Unitary-Reduct ion Operation

The famous quantum no-cloning theorem [Nature 299(1952)802] forbids replication of an arbitrary unknown quantum state. But it leaves open the follorc-ing question: If the state is not completely arbitrary, but secretly chosen from a certain set $ = {|Ψ₁>,| Ψ₂>,...,|Ψ_n>}, whether is the cloning possible? It is proved that the states from the set $ = {|Ψ₁>,| Ψ₂>,...,|Ψ_n>} can be faithfully cloned by a general unitary-reduction operation in a probabilistic fashion if and only if |Ψ₁>,| Ψ₂>,... and |Ψ_n> are linearly-independent.     

双分散颗粒体系在临界堵塞态的结构特征

堵塞行为是颗粒体系中一种常见的现象,其力学性质与堆积结构的关联非常复杂.本文采用离散元法研究了由两种不同半径颗粒组成的二维双分散无摩擦球形颗粒体系在临界堵塞态所呈现的结构特征,讨论了大小颗粒粒径比与大颗粒百分比对临界堵塞态的影响.数值模拟结果表明,当粒径比小于1.4时,临界平均接触数与大颗粒百分比关系不大,当粒径比大于1.4时随着大颗粒百分比的增大临界平均接触数先减小再增大.而临界体积分数在粒径比小于1.8时随着大颗粒百分比的增加先减小后增大,大于1.8时又基本不随大颗粒百分比而变化.大颗粒百分比在接近0或1时,系统近似为单分散体系,临界平均接触数与体积分数基本不随半径比的增大而变化;在接近0.5时,临界平均接触数随着半径比的增大逐渐减小,而临界体积分数则是先减小后增大.文中对大-小颗粒这一接触类型的百分比也进行了探讨,其值随着大颗粒百分比的增大呈二次函数的变化趋势,粒径比对这一变化趋势只有较小的影响.     

基于三维荧光与GA-RBF神经网络对茶叶中氯菊酯农药残留的检测

采用FS920稳态荧光光谱仪对绿茶和铁观音这两种不同品种茶叶的氯菊酯溶液的荧光光谱特性进行了分析,发现这两种茶叶的荧光峰均位于λ_(ex)/λ_(em)=(390~410)/675 nm,氯菊酯的荧光峰λ_(ex)/λ_(em)=300/330nm。为了准确测定这两种茶叶中氯菊酯农药残留的含量,采用遗传算法优化的径向基函数神经网络对其进行了分析,当训练到74次时,均方差精度达到10~(-3),绿茶、铁观音的氯菊酯溶液预测样本的平均回收率分别为99.35%和98.89%,平均相对标准偏差分别为1.25%和1.21%。与建立的径向基函数神经网络模型进行了对比,结果表明三维荧光分析技术与遗传算法优化的径向基函数神经网络相结合能够较好地检测出茶叶中氯菊酯农药残留的含量,检测灵敏度大大提高,检出限范围广,可达0.004 8~24 mg/kg,远低于欧盟规定的茶叶中氯菊酯最高残留限量0.1 mg/kg,为检测农药残留提供了一种快速简便的新方法。     

A Compact Exponential Operator for Generating Rotating and Squeezing Transformations

We point out that the compact exponential operator V≡exp[-i(λ₁Q²-λ₂P²)/2] (where λ₁, λ₂ are real;P and Q are momentum and coordinate operators, respectively;the units of h=m=ω=l is taken, m and ω are harmonic oscillator's mass and'frequency, respectively) is a generalized single-mode squeeze operator which can generate mixed squeezing and rotating transformations. The decomposition of V as a product of a squeeze operator and a rotating operator is derived through the technique of integration within an ordered product.The fluctuation in quadrature phases for the squeezed vacuum state generated by V is analyzed.     

Remarks on Small Superconducting Specimens in Magnetic Field and Measurements of the Lower Critical Field

We shall discuss the magnetic behaviors associated with the boundary effects for type-Ⅱ superconductors in general orientations. Using previous results, we speculate that the relation among the lower critical field H_c1, the thermodynamic critical field H_c and the upper critical field H_c2, namely H_c²～H_c1H_c2, is still approximately valid for general experimental orientations. More precisely, the magnitudes of H_c1, H_c and H_c2 are consistent with the formulae given for bulk superconductors when the typical size of the superconducting specimen is greater than the coherence length ε, provided the penetration depth λ is substituted by a modified value λ_m. Consequently, the criterion for observing type-Ⅱ superconducting magnetic behaviors also becomes λ_m>ε, although the London equation is still governed by λ. In the second part of the paper, we shall also suggest an experiment, based on the fact of H_c1. of superconducting thin films in parallel magnetic field being much higher than that of bulk superconductors, to measure H_c1 precisely, especially for extreme type-Ⅱ superconductors,without influence of the penetration barrier.     

The Strong Interaction in Chromodynamics Ⅱ

A static soliton solution is obtained from the field equations of chromodynamics. The relativistic wave equation for meson states in which the quark and antiquark interact through the intermediary of this gluon field gives rise. to the same wavefunction and mass spectra obtained before under the independent particle approximation. The calculated values of mass difference of η_c and Ψ/J particles and mass difference of Ψ(3685) and Ψ(3770) due to spin-dependent part of the interaction are in good agreement with the experiment.