类铍C III, N IV, O V离子的基态和亚稳态的直接单电离截面计算

本文使用相对论扭曲波近似计算了基态(1s22s2 1S)和亚稳态(2s2p 3P)的类铍C III, N IV和O V离子的电子碰撞直接单电离截面。计算中包括了基态的2s壳层和亚稳态的2s、2p壳层的直接单电离而没有包括1s子壳层。其结果与现有的理论和实验数据进行了比较,相对论扭曲波近似结果在外型和大小上都与近期的实验数据很一致,且与其他理论结果相比,在近阈和高能范围内与实验数据符合得更好。     

相位—啁啾调控对高次谐波光谱的影响

理论研究了在激光相位和啁啾调控共同影响下高次谐波光谱的变化。结果表明：当激光相位为0时,一阶啁啾调控使谐波能量延伸。二阶啁啾调控会呈现高强度谐波平台区。当激光相位为0.5π时,一阶啁啾调控可以获得连续平台区,但是强度较弱。在二阶啁啾调控下,谐波能量得到明显增大。通过谐波时频分析给出了不同激光波形下产生高次谐波光谱的原因。     

Evidence of self-affine multiplicity fluctuation of target residues in 84Kr-AgBr interactions at 1.7 AGeV

Self-afline multiplicity scaling is investigated in the framework of a two-dimensional factorial mo-ment methodology using the concept of the Hurst exponent (H). Analyzing the experimental data of target evaporated fragments emitted in84Kr-AgBr interactions at 1.7 AGeV revealed that the best power law behav-ior is exhibited for H = 0.3 indicating a self-affine multiplicity fluctuation pattern. A signal of multifractality is also observed from knowledge of the anomalous fractal dimension dq extracted from the intermittency exponent aq of the anisotropic phase space scenario.     

Shears mechanism in two-dimensional cranking relativistic mean field approach

Using the new two-dimensional cranking relativistic mean field (RMF) approach, the shears mechanism of magnetic rotation based on configuration πh121/2νh-211/2 in 142Gd is microscopically and self-consistently examined by investigating the aligning angular momenta of the valence nucleons.     

Normal halogen dependence of 13C NMR chemical shifts of halogenomethanes revisited at the four‐component relativistic level

The ‘Normal Halogen Dependence’ of ¹³C NMR chemical shifts in the series of halogenomethanes is revisited at the four‐component relativistic level. Calculations of ¹³C NMR chemical shifts of 70 halogenomethanes have been carried out at the density functional theory (DFT) and MP2 levels with taking into account relativistic effects using the four‐component relativistic theory of Dirac‐Coulomb within the different computational methods (4RPA, 4OPW91) and hybrid computational schemes (MP2 + 4RPA, MP2 + 4OPW91). The most efficient computational protocols are derived for practical purposes. Relativistic shielding effect reaches as much as several hundreds of ppm for heavy halogenomethanes, and to account for this effect in comparison with experiment at the qualitative level, relativistic Dyall's basis sets of triple‐zeta quality or higher are to be used within the framework of the four‐component relativistic theory taking into account solvent effects. Relativistic geometrical optimization (as compared with the non‐relativistic level) is essential for the molecules containing at least two iodines at one carbon atom. Copyright © 2016 John Wiley & Sons, Ltd.     

A relativistic quark-diquark model for the nucleon

We developed a constituent quark-diquark model for the nucleon and its resonances using a harmonic oscillator potential for the interaction. The effects due to relativistic kinetic energy correction are studied. Finally, charge form factor of the model is calculated and compared with experimental data.      

The density wave in a new anisotropic continuum model

In this paper the new continuum traffic flow model proposed by Jiang et al is developed based on an improved car-following model, in which the speed gradient term replaces the density gradient term in the equation of motion. It overcomes the wrong-way travel which exists in many high-order continuum models. Based on the continuum version of car-following model, the condition for stable traffic flow is derived. Nonlinear analysis shows that the density fluctuation in traffic flow induces a variety of density waves. Near the onset of instability, a small disturbance could lead to solitons determined by the Korteweg-de-Vries （KdV） equation, and the soliton solution is derived.     

Liquid–Vapor Phase Transitions for Systems with Finite-Range Interactions

We consider particles in ^d , d2, interacting via attractive pair and repulsive four-body potentials of the Kac type. Perturbing about mean-field theory, valid when the interaction range becomes infinite, we prove rigorously the existence of a liquid–gas phase transition when the interaction range is finite but long compared to the interparticle spacing for a range of temperature.     

Rules and reals

A ``-rule" is a sequence of pairwise disjoint sets , each of cardinality and subsets . A subset (a ``real') follows a rule if for infinitely many , .

Two obvious cardinal invariants arise from this definition: the least number of reals needed to follow all -rules, , and the least number of -rules with no real that follows all of them, .

Call a bounded rule if is a -rule for some . Let be the least cardinality of a set of bounded rules with no real following all rules in the set.

We prove the following: and for all . However, in the Laver model, .

An application of is in Section 3: we show that below one can find proper extensions of dense independent families which preserve a pre-assigned group of automorphisms. The original motivation for discovering rules was an attempt to construct a maximal homogeneous family over . The consistency of such a family is still open.