基于遗传算法的变电站巡检机器人任务路径规划方法研究

近年来,随着变电站巡检机器人在变电站中的广泛使用,巡检机器人路径规划问题越来越成为亟待解决的问题。巡检机器人在已知的拓扑地图中标记了待执行巡检任务的停靠点,不同任务需要从初始点出发经过不同的一系列停靠点再返回初始点,如何规划路径是机器人面临的问题。首先分析了路径规划面临的问题,然后通过分析拓扑地图的特征,对地图进行等价简化,再对问题进行建模使用遗传算法求解巡检任务路径规划的近似最优解。通过仿真实验证明,提出的基于遗传算法的路径规划方法是可行有效的,为变电站巡检机器人任务路径规划提供了一种有效方法。     

0.73～1.7μm超宽带微纳光纤波导全光调制器

提出了单层石墨烯包裹双锥形微纳光纤复合波导结构,构建了730~1 700nm超宽带微纳光纤波导全光调制器。通过火焰拉锥法将一根标准的通信单模光纤拉成具有双锥形的微纳光纤,在保证通光率的前提下可以极大的提升微纳光纤处的倏逝波与物质的相互作用。利用石墨烯的"超级特征",即单原子层厚度、线性色散的能带结构、超强的载流子带间跃迁及极短的弛豫时间和超宽带光与物质相互作用等,将单层石墨烯作为可饱和吸收体,包裹在双锥形微纳光纤波导的锥体上,以增强该复合波导表面倏逝波与石墨烯的相互作用。静态和动态全光调制实验中采用传统808nm低功率LD作为泵浦光,对谱宽为480~1 700nm的超连续谱探测光实现了光光调制,其泵浦光功率低于50mW,调制深度大于5.7dB,调制速率达到~4kHz。该微纳光纤波导全光调制器,在保证调制深度的情况下,用更低的泵浦功率实现了超宽带的全光调制,以简单、有效、廉价的方式兼容了当前高速光纤通信网络,打开了一扇未来对微纳超快光信号处理的大门。     

Study of radiation background at the north crossing point of the BEPCⅡ in collision mode

Understanding the radiation background at the north crossing point (NCP) in the tunnel of BEPCII is crucial for the performance safety of the High Purity Germanium (HPGe) detector, and in turn of great significance for long-term stable running of the energy measurement system. Therefore, as the first step, a NaI(Tl) detector is constructed to continuously measure the radiation level of photons as background for future experiments. Furthermore, gamma and neutron dosimeters are utilized to explore the radiation distribution in the vicinity of the NCP where the HPGe detector will be located. Synthesizing all obtained information, the shielding for neutron irradiation is studied based on model-dependent theoretical analysis.     

粲偶素衰变过程中ρπ疑难的研究

详细回顾并广泛评论了粲偶素衰变过程中有关ρπ疑难的各种理论解释和探讨. 在可能的情况下, 将有关的理论预言与相应的实验数据进行了细致的比较. 描述并讨论了三种估算ψ′和J/ψ衰变分支比比值的方法. 针对目前的现状, 指出为了深入理解ρπ疑难以及更进一步了解粲偶素衰变的动力学机制, 需要从理论探究、唯象分析和实验测量多方面进行系统、深入和全面的工作.     

Study of the semileptonic charm decays D(0)-->pi(-)l(+)nu and D(0)-->K(-)l(+)nu

We investigate the decays D(0)-->pi(-)l(+)nu and D(0)-->K(-)l(+)nu, where l is e or mu, using approximately 7 fb(-1) of data collected with the CLEO III detector. We find R(0) identical with B(D(0)-->pi(-)e(+)nu)/B(D(0)-->K(-)e(+)nu)=0.082+/-0.006+/-0.005. Fits to the kinematic distributions of the data provide parameters describing the form factor of each mode. Combining the form factor results and R(0) gives |f(pi)(+)(0)|(2)|V(cd)|(2)/|f(K)(+)(0)|(2)|V(cs)|(2)=0.038(+0.006+0.005)(-0.007-0.003).     

Selective spreading and jetting of electrically driven dielectric films

We study the electrically driven spreading of dielectric liquid films in wedge-shaped gaps across which a potential difference is applied. Our experiments are in a little-studied regime where, throughout the dynamics, the electrical relaxation time is long compared to the time for charge to be convected by the fluid motion. We observe that at a critical normal electric field the hump-shaped leading edge undergoes an instability in the form of a single Taylor cone and periodic jetting ensues, after which traveling waves occur along the trailing thin film. We propose a convection-dominated mechanism for charge transport to describe the observed dynamics and rationalize the viscosity dependence of the self-excited dynamics.     

相位共轭皮秒光脉冲的直接观察和记录

利用条纹照相机直接观察和记录了由全息相位共轭技术产生的相位共轭的皮秒光脉冲。实验结果与理论相符合。 关键词：     

Balance of mass, momentum, and energy in splintering central collisions for 40Ar up to 115 MeV /Nucleon

For central collisions of (17-115)A MeV 40Ar+Cu, Ag, Au, an overall balance is determined for the average mass, energy, and longitudinal momentum. Light charged particles and fragments are separated into forward-focused and isotropic components in the frame of the heaviest fragment. Energy removal by the isotropic component reaches 1-2 GeV. For such high deposition energies, statistical multifragmentation models predict much more extensive nuclear disassembly than is observed.     

Preemptive scheduling of interval orders is polynomial

In 1979, Papadimitriou and Yannakakis gave a polynomial time algorithm for the scheduling of jobs requiring unit completion times when the precedence constraints form an interval order. The authors solve here the corresponding problem, for preemptive scheduling (a job can be interrupted to work on more important tasks, and completed at a later time, subject to the usual scheduling constraints.) The m-machine preemptive scheduling problem is shown to have a polynomial algorithm, for both unit time and variable execution times as well, when the precedence constraints are given by an interval order.     

一类非线性奇摄动分数阶微分方程的渐近解

研究了一类奇摄动非线性分数阶微分方程边值问题.在适当的条件下,首先求出了原问题的外部解,然后利用伸长变量、合成展开法和幂级数展开理论构造出解的边界层项,并由此得到解的渐近展开式.最后利用微分不等式理论,讨论了问题解的渐近性态,得到了原问题解的一致有效的渐近估计式.