阻尼对空爆荷载等效静载动力系数的影响

为考查阻尼参数对空爆荷载等效静载动力系数的影响,理论推导了空爆荷载下结构等效单自由体系弹塑性位移解及延性比解,设计并计算了阻尼比0.000 1～0.1、延性比1～4的20种典型工况的动力系数,并与现行抗爆设计规范动力系数公式结果进行了对比。结果表明:阻尼比小于0.000 1时可基本代表无阻尼状态,阻尼比0.01的动力系数比无阻尼的最大降低幅度为2.08%,数值差异很小,因此阻尼比为0.01以内时,可忽略阻尼对动力系数的影响;阻尼比0.05的动力系数比无阻尼的降低幅度约9.92%,数值差异较大,认为阻尼比0.05以上时将具有明显的经济效益;现行设计规范动力系数更适用于柔性结构体系,运用于刚性结构抗爆设计时,计算误差较大,对阻尼比较小的结构设计更不利。     

Theoretical Study on Thermodynamic Properties and Hydrophilicity of Polychorinated Phenothiazines （PCPTZs）

The thermodynamic properties of 135 polychlorinated phenothiazines (PCPTZs) in the standard state are calculated using a combination of quantum mechanical computations performed with the Gaussian 03 program at the B3LYP/6-311G** level, and their octanol-water partition coefficients (logKow) are calculated based on group contributions. The chlorine substitution pattern strongly influenced the thermodynamic properties and hydrophilicity of the compounds. The thermodynamic properties of congeners also depend on the chlorine substitution pattern. The effect of chlorine substitution pattern is quantitatively studied by considering the number and position of Cl atom substitution (NPCS). The results show that the NPCS model may be used to predict the thermodynamic properties and hydrophilicity for all 135 PCPTZ congeners.     

Properties of Traffic Risk Coefficient

We use the model with the consideration of the traffic study the relationship between the traffic risk coefficient interruption probability （Physica A 387（2008）6845） to and the traffic interruption probability. The analytical and numerical results show that the traffic interruption probability will reduce the traffic risk coefficient and that the reduction is related to the density, which shows that this model can improve traffic security.     

Clebsch-Gordan系数的对称性

利用Schur引理确定了角动量耦合的Clebsch-Gordan系数按照其定义所允许的任意程度,然后利用正交归一关系和相位知识,导出了Clebsch-Gordan系数的对称性.     

基于变分有限元方法的S809翼型的改进设计

翼氆的升力和阻力特性直接影响到叶轮机或机翼的性能,传统风力机翼型的外形是基于经验和半经验的方法得到,本文采用变域变分有限元方法,以NREL S809翼型为原形,通过改进其叶片表面的目标压力分布,进行该翼型的改进设计,并对新设计出的翼型在0°～20°攻角范围内进行CFD数值模拟,得到的结果与原始S809翼型在升阻力系数,...     

Energy dissipation of a ring-like metal rubber isolator

Metal rubber （MR） is a kind of homogeneous poroelastic damping material made of metal wire. In this paper, by ana- lyzing the forces on the MR isolator and the MR element, the hysteresis loops of the force and deformation are studied and verified by experiments. The results show that the force and displacement hysteresis loop of the MR isolator is described by the force and deformation hysteresis loops of the MR elements. In addition, the relationship between the energy dissipation coefficient of the MR element and that of the MR isolator is derived. The energy dissipation coefficient is programmed and calculated by MATLAB using experimental data, and the results are compared with the theoretical value. It is the basis for the design and applied research of the MR isolator in a future study.     

Analytical Solitary Wave Solutions to a （3＋1）-Dimensional Gross-Pitaevskii Equation with Variable Coefficients

A （3＋1）-dimensional Gross-Pitaevskii （GP） equation with time variable coefficients is considered, and is transformed into a standard nonlinear Schrodinger （NLS） equation. Exact solutions of the （3＋1）D GP equation are constructed via those of the NLS equation. By applying specific time-modulated nonlinearities, dispersions, and potentials, the dynamics of the solutions can be controlled. Solitary and periodic wave solutions with snaking and breathing behavior are reported.     

自然数幂方和用二项系数表示的系数公式

得到了自然数幂方和由二项系数表示的系数a_i~(k)的公式,和由排列数表示的系数b_i~(k)的公式,证明了系数存在唯一性及系数间的若干重要性质,给出了计算系数的C-语言程序.     

Dynamic quality of transmission optimization and global impairments control in reconfigurable transparent WDM networks:schemes and demonstrations

<正>Two novel dynamical quality of transmission(QoT) optimization schemes with explicit optimization targets and accurate end-to-end QoT estimation are proposed for reconfigurable transparent wavelength-division multiplexing(WDM) networks.Numerical simulations show that the scheme of quality(Q) best has the best Q factor improvement with large attenuation adjustment.The scheme of Q allowable can achieve minimized number of tuning sites and attenuation adjustment and also improve the Q factor of light path to the required value.In addition,the idea of dynamic QoT optimization and global impairment control has been experimentally demonstrated on a simple mesh network by the cooperation of a control plane and tunable devices.