离散群

Discrete mechanics,dynamical equation,infinitesimal transformation group,symmetry,conserved quantity

中文关键词离散力学，动力学方程，无限小变换群，对称性，守恒量

The method that combines the effective - field renormalization group with the discretized path - integral representation is extenged to study phase transition of the transverse Ising model in a quantum - spin system on the plane triangular lattice.

将离散路径积分表示下的有效场重整化群技巧推广应用于平面三角晶格上量子自旋横向Ising模型的相变研究，在这个方法中，注意区分了两种具有相同配位数而不同几何构形的晶体，并且考虑了起伏的影响，在二阶累积量近似下，得到了接近于精确解的临界值。

Especially,occurrence of Lie group method s associated with wants of the dynamics,it can be used to discretion of the equations in spaces of curvature,and it cann t have the drift off the manifold of solution.

特别是所谓的的李群方法是在动力学问题的需求下诞生的，它能在弯曲的空间中进行离散化，根本不会出现'违约问题'。

The security of all these algorithms is based on the difficulty in factorizing large integer and computing discrete logarithm.

这些方案的安全性都是基于大数分解的困难性和有限群上计算离散对数的困难性。

Throuth computer simulation, we have numerically investigated the effect of pulse walkoff on optical pulse compression based on cross phase modulation in the normal dispersion regime of single mode fibers.

通过数值模拟，分析了脉冲离散效应对单模光纤正群速色散区基于暗孤子交叉相位调制的脉冲压缩的影响，并提出了减轻这种影响的办法。

This paper proposed a modified Particle Swarm Optimization algorithm to solve the mixed model assembly line sequencing problem in discrete space with two objectives:total production rate variation and total idle-overload time.

提出在离散空间用一种改进的微粒群优化算法来解决混流装配线的多目标排序问题，考虑两个目标：总生产变化率最小和总闲置－超载时间最小，并对两个目标函数进行了规范化处理以消除量纲的影响。

The w-radicals of cyclic submodules of finitely generated free modules over unique factorization domains are discussed.

C中有限生成子群的一条离散准则。11。讨论了唯一分解整环中有限生成自由模的循环子模的w-根。

In the process of this item, after the mainly uncertainties affecting the network planning are detailedly researched, some flexible planning models such as Blind Number Method and Scenario Method are proposed. Because power network planning is a nonlinear, discrete, multi-peak, multi-objective and nondifferentiable problem, it is very hard to be solved. Ant Colony Algorithm is an advanced metaheuristic method and has potential to deal with network planning problems.

本项目的研究过程中，针对影响电网规划的不确定性因素做了深入的定性和定量分析，采用盲数理论和多场景技术建立了多种具有良好适应性和灵活性的电网规划模型；同时，针对电网灵活规划模型非线性、离散性、多目标及目标函数不可微等特点，对多种优化算法在处理此类问题时的性质进行了分析和对比，并最终采用蚁群算法较好地解决了电网灵活规划问题。

In order to meet the complex requirements in hydropower stations optimal operation, a hybrid optimal model consisted DPSA,DDDP and POA organically with the system constrain of up-down bound is presented.The model is seized of the advantages including decreasing the number of hydropower stations by DPSA,minifying the discrete states by DDDP and reducing the computational time by POA.

2针对规模库群的复杂调度要求，结合逐次逼近动态规划可以减少每次参与计算的电站数目，增量动态规划减少离散状态数目，而逐步优化算法减少计算时段数目等特点，以满足系统上下限带宽的发电量最大为目标，提出耦合DPSA，DDDP及POA的混合求解算法来建立梯级长期优化调度模型。

This paper aims at the time performance of the entire system and uses the task flow graph as the system model.Based on it,an evaluation function based on the priority is achieved,then a new algorithm combining the search space smoothing technology with discrete particle swarm is proposed and whose parameters can be adjusted automatically.At last,the combination problem is addressed.

以提高系统时间性能为目标，利用任务流图构造系统模型，在其上实现了基于优先权的评价函数，提出了搜索空间平滑技术与离散粒子群算法相结合的软硬件划分算法，并且解决了两者的融合问题，并能根据系统信息动态适应调整算法参数。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。