非相对论弱相互作用玻色气体的有效场理论处理

采用有效场理论研究了非相对论弱相互作用玻色-爱因斯坦凝聚量子气体的一般性质.在分析了系统的不可重整化性质后,从有效拉氏量出发,计算了最低阶环路修正下拉氏量参量的运动耦合常数(running coupling constant)的形式,并且得到了相应的微分方程.研究结果表明,不同于相对论玻色气体的有效理论,对非相对论弱相互作用的玻色气体,可以移除该有效理论中的内禀能量尺度,即可令该有效理论的内禀能量尺度取无穷大值.所得的分析结果将有助于对玻色-爱因斯坦凝聚的临界性质和行为的深入研究.     

A kind of new algebraic Rossby solitary waves generated by periodic external source

In the article, by employing multiple-scale, perturbation method, a new model is derived to describe the algebraic Rossby solitary waves generated by periodic external source in stratified fluid. The local conservation laws and analytic solutions of the model are obtained, and the breakup properties are discussed. By numeric simulation, some problems on the generation and evolution of the algebraic solitary waves under the influence of periodic external source are theoretically investigated. The results show that besides the solitary waves, an additional harmonic wave appears in the region of the external source forcing. Furthermore, the periodic variation of the external source forcing can prevent solitary waves from breaking. Meanwhile, the detuning parameter has an important effect on the breakup of the algebraic Rossby solitary waves.     

小波变换的潮滩沉积物含水量预测

潮滩沉积物水分的分布在空间和时间上会有很大的变化,含水量的变化会导致沉积物中生源要素含量的变化。因此,实时、准确、快速的监测潮滩沉积物含水量,对了解潮滩的各种特性,掌握潮滩生源要素信息,潮滩资源的开发有着重要意义。采集青岛市东大洋村潮间带的沉积物115份,分别测定新鲜样品、风干4周、风干8周样品的可见近红外光谱和含水量。以db10小波基和sym6小波基对原始光谱进行小波变换,采用偏最小二乘回归建立潮滩沉积物含水量模型。通过10阶小波变换获取原始光谱的低频信息A_n和高频信息D_n(n=1, 2, …,10),通过原始光谱S分别与高频信息D_n做差值,得到S-D_n,对A_n,D_n和S-D_n建立潮滩沉积物含水量模型,并对模型结果进行分析。原始光谱建立模型的R2_p为0.841,RMSEP为2.767,RPD值为2.481。通过对db10小波基变换后的低频和高频信息分析,无用信息主要集中在D₃和D₄,去除D₃和D₄建立的含水量模型,相比于原始光谱模型精度有明显提高,R2_p为0.878,RMSEP为2.501,RPD值为2.749;通过sym6小波基变换后进行分析,无用信息主要集中在D₅和D₉,去除D5和D9建立含水量模型与原始光谱模型相比,精度也有一定提高,R2_p为0.87,RMSEP为2.475,RPD值为2.768。因此通过小波变换对原始光谱划分低频信息和高频信息进行分析,能够有效找到潮滩沉积物含水量的干扰信息,实现特征信息提取,从而建立准确度更高的潮滩沉积物含水量模型,为潮滩沉积物含水量实时、动态监测提供理论基础。     

Fluorinated tris(pyrazolyl)borates. Syntheses and characterization of sodium and copper complexes of [HB(3-(CF3),5-(Ph)Pz)3]−

Sodium salt of the fluorinated tris(pyrazolyl)borate ligand [HB(3-(CF₃),5-(Ph)Pz)₃]⁻ has been synthesized from the corresponding pyrazole and NaBH₄ in high yield. It forms stable adducts with oxygen-based donors like THF and water. [HB(3-(CF₃),5-(Ph)Pz)₃]Na(THF) is monomeric in the solid state whereas {[HB(3-(CF₃),5-(Ph)Pz)₃]Na(H₂O)}_n forms a polymeric chain structure. These tris(pyrazolyl)boratosodium adducts show intra and/or inter-molecular sodium–fluorine interactions. X-ray crystal structures of [HB(3,5-(CF₃)₂Pz)₃]Na(OEt₂) and {[HB(3-(CF₃),5-(CH₃)Pz)₃]Na(H₂O)}₂ also display similar CF⋯Na contacts. The copper carbon monoxide complex [HB(3-(CF₃),5-(Ph)Pz)₃]CuCO was prepared by treating [HB(3-(CF₃),5-(Ph)Pz)₃]Na(THF) with CuOTf in the presence of CO. The infra-red stretching frequency data show relatively high ν_CO value (2103 cm⁻¹) indicating the presence of highly electrophilic copper site on [HB(3-(CF₃),5-(Ph)Pz)₃]CuCO. Crystal structure of 3-(CF₃),5-(Ph)PzH is also reported. It forms “tub” shaped tetramers in the solid state.     

Transport in polygonal billiards

We present in this work a numerical study of the dynamics of ensembles of point particles within a polygonal billiard chain. This billiard is a system with no exponential instability. Our numerical results suggest that some members of the family exhibit normal diffusive behavior while others present anomalous diffusion. Our conclusions are drawn from the numerical evaluation of the mean square displacement, the velocity autocorrelation function and its spectral analysis. Furthermore we analyze the properties of the incoherent scattering function. The super Burnett coefficient seems to be ill defined in all systems. The multifractal analysis of the spectrum of the velocity autocorrelation functions is also reported. Finally, we study the heat conduction in our polygonal chain.     

A new mixed valence VIV–V and Li phyllosilicate: swelling,magnetic and conductive properties

This paper presents the synthesis and characterisation of a new V–Li phyllosilicate, Li₂V_0.95Si₄O₁₀(OH)_1.24F_0.76, under hydrothermal conditions. Part of the alkali is located in the interlayer spacing while the rest occupies the octahedral layer together with V^IV and V^V. This silicate exhibits a mixed valence character and different properties, such as ferromagnetic order at low temperature, ionic conductivity and swelling upon exposure to moisture atmosphere. Thus, the basal spacing increases from 12.3 to 16.3 Å.