7个经典Ramsey数R(k,l)的新下界

利用构造性的方法,得到7个经典Ramsey数的新下界R(3,29)≥174,R(4,23)≥272,R(5,24)≥488,R(7,12)≥312,R(8,18)≥728,R(8,20)≥860,R(9,21)≥1278.     

实Clifford分析中,双正则函数向量的非线性边值问题

研究实Clifford分析中关于多个未知函数的双正则函数向量的一个非线性边值问题     

PVC/EVA/SBS共混体系研究

利用溶液成膜法制备了PVC/SBS薄膜 ,对其表观形态、力学性能进行了研究 ,并讨论了EVA对体系的增容作用。发现EVA在一定浓度范围内能增加PVC与SBS的相容性 ,提高断裂伸长率 .测量了溶液的相对粘度 ,得出了相反转浓度点。     

三甲川菁染料敏化TiO2纳米结构电极的光电化学

研究了三甲川菁染料敏化ＴｉＯ２ 纳米结构电极的光电化学行为．结果表明,使用该染料敏化可显著提高ＴｉＯ２ 纳米结构电极的光电流,使电极的吸收波长红移至可见光区,光电转换效率得到明显改善,ＩＰＣＥ值最高可达１２－１ ％ ．     

基于小波边缘提取的灰度图象联合相关识别预处理

本文将小波变换方法用于灰度图象的联合变换相关识别中,采用不同的尺度因子对输入图象进行边缘提取预处理,使相关识别结果得到不同程度的改善.通过计算机模拟对比了一阶、二阶微商的边缘提取方法和小波变换边缘提取方法的预处理结果和对识别的影响,在同时衡量相关识别能力及其对噪音的敏感性前提下,小波变换边缘提取预处理明显优于各种微商边缘提取方法.调节小波变换尺度因子还能使识别能力与噪音敏感性这两方面得到更好地均衡,使小波变换边缘提取预处理能够适应不同的图象输入条件和相关输出要求.结果表明,在联合变换相关识别中采用小波变换对输入图象进行预处理是一种更理想的方法。     

Linearity Requirement for a Linear Frequency Modulation Lidar

The nonlinear of the frequency modulation in linear frequency modulation (LFM) lidar seriously affects the accuracy of range and velocity. We describe the influence of nonlinear of the frequency modulation on the accuracy. The frequency-domain analysis of heterodyne signal is used to deduce the linearity requirement for LFM lidar.     

Photochemische Reaktionen von Cyclopentadienylbis(ethen)rhodium mit Benzolderivaten

Photochemical Reactions of Cyclopentadienylbis(ethene)rhodium with Benzene Derivatives During UV irradiation of [CpRh(C₂H₄)₂] ( 1 ) (Cp = η⁵‐C₅H₅) in hexane in the presence of hexamethylbenzene the di‐ and trinuclear arene bridged complexes [(CpRh)₂(μ‐η³ : η³‐C₆Me₆)] ( 3 ) and [(CpRh)₃(μ₃‐η² : η² : η²‐C₆Me₆)] ( 4 ) are formed besides known [CpRh(η⁴‐C₆Me₆)] ( 2 ). It was shown by a separate experiment that 3 besides small amounts of 4 is formed by attack of photochemically from 1 arising CpRh fragments at the free double bond of the η⁴‐bonded benzene ring in 2 . Irradiation of 1 in the presence of diphenyl (C₁₂H₁₀) affords the compounds [(CpRh)₂(μ‐η³ : η³‐C₁₂H₁₀)] ( 5 ) and [(CpRh)₃(μ₃‐η² : η² : η²‐C₁₂H₁₀)] ( 6 ) as analogues of 3 and 4 , in the presence of triptycene (C₂₀H₁₄) only [(CpRh)₂(μ‐η³ : η³‐C₂₀H₁₄)] ( 7 ) is obtained; the bridging in 5 , 6 , and 7 always occurs via the same six‐membered ring of the corresponding ligand system. During the photochemical reaction of 1 in the presence of styrene (C₈H₈) substitution of the ethene ligands by the vinyl groups with formation of [CpRh(C₂H₄)(η²‐C₈H₈)] ( 8 ) and known [CpRh(η²‐C₈H₈)₂] ( 9 ) is observed exclusively. The new complexes were characterized analytically and spectroscopically, in the case of 3 also by X‐ray structure analysis.     

Gluon-pair-creation production model of strong interaction vertices

By studying the \begin{document}$\eta_c$\end{document} exclusive decay to double glueballs, we introduce a model to phenomenologically mimic the gluon-pair-vacuum interaction vertices, namely the \begin{document}$0^{++}$\end{document} model. Based on this model, we study glueball production in pseudoscalar quarkonium decays, explicitly \begin{document}$\eta_c \to f_0(1500)\eta(1405)$\end{document}, \begin{document}$\eta_b\to f_0(1500)\eta(1405)$\end{document} , and \begin{document}$\eta_b\to f_0(1710)\eta(1405)$\end{document} processes. Among them \begin{document}$f_0(1500)$\end{document} and \begin{document}$f_0(1710)$\end{document} are well-known scalars possessing large glue components, while \begin{document}$\eta(1405)$\end{document} is a potential candidate for a pseudoscalar glueball. The preliminary calculation results indicate that these processes are marginally accessible in the presently running experiments BES III, BELLE II, and LHCb.     

Analytical expressions of non-relativistic static multipole polarizabilities for hydrogen-like ions

Analytical formulas for the static multipole polarizabilities of hydrogen-like ions are derived by using the analytical wave functions and the reduced Green function and by applying a numerical fitting procedure.Our results are then applied to the studies of blackbody radiation shifts to atomic energy levels at different temperatures.Our analytical results can be served as a benchmark for other theoretical methods.     

A dynamical transition of a chain of charged particles in a 2D substrate potential

The transport of a chain of charged particles with a transverse degree of freedom is investigated in a 2D asymmetric potential. Here, the energy of the periodic driving force is converted into motion in the vertical direction. The analysis exhibits a transition from stick-slip motion to periodic oscillation. The chain velocity can be controlled to an optimized value by adjusting system parameters, such as the amplitude and frequency of the periodic force. The existence of a resonance platform indicates resonance between the motion of the chain and the periodic force as coupling strength increases adiabatically. The atomic configuration and the transverse degree of freedom also play key roles in the control.