Application of strength reduction method to dynamic anti-sliding stability analysis of high gravity dam with complex dam foundation

Considering that there are some limitations in analyzing the anti-sliding seismic stability of dam-foundation systems with the traditional pseudo-static method and response spectrum method,the dynamic strength reduction method was used to study the deep anti-sliding stability of a high gravity dam with a complex dam foundation in response to strong earthquake-induced ground action.Based on static anti-sliding stability analysis of the dam foundation undertaken by decreasing the shear strength parameters of ...     

钢丝非稳态加热的运行速度计算

在热处理钢丝时,大多在对流换热条件下对钢丝进行加热,铅浴热处理是其加热方法之一。本文根据传热学理论,依据能量守恒原理,应用集总热容法,对钢丝在第三类边界条件下的加热建立合适的数学模型,推导出第三类边界条件下的钢丝在对流换热情况时的加热时间计算式,给出了钢丝表面到温和钢丝中心到温时间表达式,由此导出钢丝非稳态加热的运行速度计算式,为钢丝热处理工艺的制定和钢丝加热炉(槽)的设计提供理论计算依据。     

Research on forecasting model of sandstone deformation rate during sine wave loading segment under the lag effect

To reduce data variance caused by individual differences of different samples,a new experimental method is proposed by loading and unloading the axial forces with different frequencies and different waves of a certain load amplitude to the same rock sample without damaging it.Lag time segments are defined and fractionized into segments I and Ⅱ.Criterions for seg-mentation,definitions of relevant parameters and empirical analysis are also offered afterwards.In the course of sinusoidal loading,the serious pea...     

对资金时间价值的再认识

在对资金时间价值的内涵进行分析的基础上,文章提出了资金时间价值应用中需要注意的一些事项。这对更好地运用时间价值的观念去解决实际问题具有参考价值。     

Fold-Hopf bifurcation in a simplified four-neuron BAM (bidirectional associative memory) neural network with two delays

The bidirectional associative memory (BAM) neural network with four neurons and two delays is considered in the present paper.A linear stability analysis for the trivial equilibrium is firstly employed to provide a possible critical point at which a zero and a pair of pure imaginary eigenvalues occur in the corresponding characteristic equation.A fold-Hopf bifurcation is proved to happen at this critical point by the nonlinear analysis.The coupling strength and the delay are considered as bifurcation parame...     

Stochastic stability of quasi-integrable Hamiltonian systems with time delay by using Lyapunov function method

The asymptotic Lyapunov stability of one quasi-integrable Hamiltonian system with time-delayed feedback control is studied by using Lyapunov functions and stochastic averaging method.First,a quasi-integrable Hamiltonian system with time-delayed feedback control subjected to Gaussian white noise excitation is approximated by a quasi-integrable Hamiltonian system without time delay.Then,stochastic averaging method for quasi-integrable Hamiltonian system is used to reduce the dimension of the original system,a...     

时间序列在FY2C云检测中的应用

对FY2C时间序列图像的研究分析表明,时间序列云图的像元亮温/温度时较差(一小时之内亮温/温度差,也称亮温/温度时变化)规律可以用于标称图云检测,能较好地实现运动剧烈的云和运动云区的边缘云检测.以中国区域内地面站资料为标准进行对比分析,利用时间序列结合晴空背景场方法进行云检测,在2007年1月和6月的准确率分别为72.89%和79.94%.与目前业务云检测相比,利用静止卫星高时间分辨率特征在一定程度上改善了低云和薄云的检测.利用了静止卫星高时间分辨率的特点,并为动态求取阈值提供了一种新思路,具有一定的应用价值.     

Optical properties of CdSe quantum dots grown on ZnSe and ZnBeSe by molecular beam epitaxy

We report detailed studies of the optical properties of CdSe quantum dots (QDs) grown on ZnSe and ZnBeSe by molecular-beam epitaxy (MBE). We performed steady-state and time-resolved photoluminescence (PL) measurements and observe that nonradiative processes dominate at room temperature (RT) in the CdSe/ZnBeSe QDs structures, though these nonradiative processes do not dominate in the CdSe/ZnSe QDs structures up to RT. We performed secondary ion-mass spectrometry (SIMS) measurement and propose that the oxygen incorporation in the ZnBeSe layers (possibly caused by the reactivity of Be) may contribute to the dominant nonradiative processes at high temperatures in the QDs grown on ZnBeSe.     

缓冲气体对超辐射光抽运远红外激光器的影响

以NH3作为远红外激光的工作气体 ,以N2 作为缓冲气体 ,对加入缓冲气体前后的小型超辐射光抽运远红外激光器作理论比较研究。基于缓冲气体作用机理模型 ,计算出激光工作物质的综合弛豫时间 ;通过解半经典的密度矩阵方程 ,计算出远红外激光输出的频谱特性和工作气压。计算表明 ,加入缓冲气体后 ,远红外激光的输出得到提高 ;存在一个最佳混合气体比例 ,在这一比例下远红外激光输出达到最大 ;加入缓冲气体后 ,最佳工作气压比加入缓冲气体前获得提高。     

实时数据库及在电厂集成自动化系统中的应用

从控制信息系统集成角度出发 ,在简述火力发电厂自动化发展的基本现状和分析比较实时数据库与关系数据库异同的基础上 ,结合萧山电厂集成自动化系统项目 ,总结了实时数据库工程应用的关键技术 ,最后提出了实时数据库的选型原则。