特征参数

Based on systematic analysis, nine seismometry parameters that response earthquakes well in North China are selected, which are seismic frequency, seismicity scale, mf-value, b-value, D-value,η-value, seismicity intensity entropy and seismicity time entropy. Using synthetic anomaly index method, we calculated their seismic anomaly index values separately and synthesized these values into a chronogenesis curve. After studying its short-term anomaly characteristics to earthquakes, the criterion index for M≥5.8 earthquakes in North China is obtained. The R-value test indicts that it has good prediction effect.

在系统分析并筛选出华北地区地震频度、地震活动标度、mf值、调制比、b值、D值、η值、地震活动强度熵和地震活动时间熵等映震较好的9项测震学参数基础上，应用综合异常指数方法，分别计算了它们各自的地震异常指数时序值，进而合成得到华北地区测震学综合异常指数时序曲线，通过研究其地震短期异常特征，给出了华北地区M≥5.8地震短期综合预测的判据指标，经R值评分检验表明，该指标具有较好的地震预测效能。

Some new idea and techniquesabout statistic tangent distance, compute tangent vector based on Singular Value Decomposition,the choice of transformation parameters, dimension decrease based on SVD, feature extractionbased on Mahalanobis distance are proposed in the dissertation.

在统计切线距离、基于奇异值分解求解切线向量、变化参数的选择、基于奇异值分解的降维、基于马氏距离的特征选择等方面提出了自己的新方法。

Based on the analysis of dip angle, friction coefficient between rigid bodies, influence effect of floor sliding block and roof fracture rock-mass, working resistance of support as well as compound characteristics of face surrounding rock, main factors which lead to destabilize in system "R-S-F" were obtained, and the controlling pattern of dynamic stability of firming bedding, controlling keys, achieving the goal were also established.

通过对工作面围岩组成特征、支架工作阻力、顶板破断岩块及底板破坏滑移体影响效应、刚体之间的摩擦因数以及煤层倾角等因素的分析，给出了引发"R-S-F"系统失稳的主导参数，确定了"稳固基础，控制关键，达到目的"的"R-S-F"系统动态稳定性控制模式和现场生产管理过程中需注意和解决的关键技术问题。

To all project practicality, the introduction is given to the operational characteristics, the methods for calculation and the researching actuality of the tail tunnels with sloping ceiling underground hydropower stations the Three Gorges. This paper has discussed in detail the characteristic method being the same with the compressive flow and the Priessmann solution being the same with the free-surface-pressure flow. And how to deal with boundary conditions has been expatiated. Also hydraulic transient process of tremendous load fluctuation in the tail tunnels with sloping ceiling has been numerical simulated and the Fortran program for numerical simulation has been given. The paper gain the maximal press for tail end of the shell, the maximal rising rate of rotational speed of generating set, the maximal vacuum degree for inlet of the tail tunnels and so on under 11 kinds conditions of tremendous load fluctuation. These conditions include the design conditions, the check conditions and the superposition conditions. Finally, the computing results have been analyzed and summarized. The end chapter is the general comment of the whole-length content and the describing of the intending view of researching.

本文以三峡右岸地下电站尾水洞设计为背景，从工程实际出发，阐述了变顶高尾水洞的工作特性、使用范围及其研究现状；详细论述了适用有压流的特征线法、适用明满交替流的普里斯曼解法等数学模型；边界条件的给定和明满交替流的计算方法；用Fonran语言编制了数值计算程序，对三峡右岸地下电站变顶高尾水洞的大波动工况进行了数值模拟，分别得出了在设计工况、校核工况和叠加工况下蜗壳末端最大压力上升值、机组最大转速上升值和尾水管进口最大真空度等重要参数；对数值计算结果进行了详细分析并得出了有价值的结论；最后展望了今后水电站变顶高尾水洞的研究方向。

Solano L%Brunet P Constructive constraint-based model for parametric CAD system 10.1016/0010-4485(94)90104-X Computer-Aided Design , 1994,8

刘雄伟%郑海波%屠晓明参数化特征造型中拓扑结构变异的一种解决方法计算机辅助设计与图形学学报， 2001，3

The characteristics of cutting edge and cutting advantages for a new type of ball end mill with space curve cutting edge is introduced,the calculating method of curve geometric parameters is explained,and the manufacture technology is presented.

介绍了一种新型空间曲线刃球头铣刀的刃形特征和切削优点，详细分析了其空间几何参数的计算方法，简要说明了其制造工艺。

Often there is a tradeoff between temporal resolution of a measurement and its spatial precision.

这三个方面特征的表现参数即为空间分辨率、光谱分辨率和时间分辨率。

The information fusion model for weld spot nugget is established through parameter selecting and characteristic information extracting.

通 过参数选择、特征信息提取，建立了点焊过程多信息融合模型。

Compared with IEKCA, GKPSOKCA needs less parameters to determine, can be easily implemented, and has stable convergence characteristic with good computational efficiency.

粒子群K均值聚类算法需要调整的参数少，易于实现，计算速度快，且具有稳定的收敛特征，能很好满足群控系统实时性的要求。

The relation between the parameter of ground motion and time is transformed into a pure random process with the amplitude varying with time. Based on the concept that there is the scaling invariant fractal structure in the transmission of earthquake motion and the self-affinity of the ground motion signal in time domain, an assumption is deduced that the curve of the stationary random noise of the ground motion varying with time is a fractal graph.

将一个运动参数的时间变化过程转化为具有时变振幅的一个纯随机振荡问题，运用地震运动传递具有无特征尺度的分形结构和地运动时域信号具有统计自相似性的概念，提出地面运动随机平稳噪声的时变曲线是一条分形曲线的假设。

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。