用DQM求解成层地基一维非线性固结问题

由于多层地基的一维非线性固结问题求解的复杂性,其解析解很难求得。本文基于Davis和Raymond一维非线性固结理论,利用DQM(Differential Quadrature Method)导了初始有效应力沿深度变化、任意边界条件、任意荷载作用下成层地基一维非线性固结的统一表达式,求得了孔压、有效应力和平均固结度的解答。通过解的收敛性分析讨论了DQM解的有效性。由于DQM解对于固结间题各种复杂条件具有统一的矩阵表达式,更便于编程计算和工程应用。最后,用本文解答对三层地基一维非线性固结问题进行了讨论。     

基于刚性约束的双移动机器人协同定位

准确、快速的状态估计是保证多机器人顺利完成协作搬运任务的关键.然而,大部分现有多机器人协同定位方法都存在一定的局限性,往往无法同时兼顾定位精度与计算复杂度.因此,本文从协作搬运任务的特点出发,将距离与方位的刚性约束条件引入协同定位中,同时根据机器人之间的紧密耦合关系建立起通用有效的运动模型和量测模型.最终在此刚性约束系统建模的基础上,提出一种基于高斯-厄米特求积分卡尔曼滤波（Quadrature Kalman Filter,QKF）的双移动机器人协同定位方法.仿真实验结果表明：与基于无约束模型的QKF协同定位方法相比,本文所提方法不但具有更高的定位精度,而且计算复杂度大大降低,有助于实现多机器人实时协同定位.     

一致网格上二次样条插值及其在积分中的应用（英）

In this paper an error estimate is derived, if λ∈[0, 1], for tile lacunaryquartic C²-spline interpolant which interpolates the first derivative of a given smooth function at the mesh points and as well as its second derivative at an arbitrary interior point between consecutive knots, if the mesh is uniform. Moreover, all application to quadratures is also presented.     

三共振准相位匹配光学参量振荡器反射抽运场的正交位相压缩

利用全固化单频Nd∶YVO₄激光器抽运由periodically poled lithium niobate(PPLN)准相位匹配晶体组成的光学参量振荡器,通过调节晶体的温度,在信号模与闲置模近简并的情况下,完成了抽运场与两个亚谐波模在腔内同时共振,实现了光学参量振荡器的极低阈值运转(阈值为1.2mW);当抽运功率为阈值抽运功率的2.8倍时,观察到反射抽运光的正交位相压缩,压缩度达1.1dB.数值计算与实验结果一致     

非线性抛物型方程有限元法数值积分的有效性

Abstract. The effect of numerical integration in finite element methods applied to a class of nonlinear parabolic equations is considered and some sufficient conditions on the quadrature scheme to ensure that the order of convergence is unaltered in the presence of numerical integration are given. Optimal Lz and H1 estimates for the error and its time derivative are established.     

一种无人机载合成孔径雷达宽带波形产生及正交接收的实验研究

对无人机载合成孔径雷达的宽带波形产生及正交接收进行了分析、研究,给出了基于数字直读和模拟正交解调的实验结果,该技术已应用于某超宽带VHF/UHF合成孔径雷达中,取得了较好的效果。     

Molecular integrals by numerical quadrature. I. Radial integration

 This article presents a numerical quadrature intended primarily for evaluating integrals in quantum chemistry programs based on molecular orbital theory, in particular density functional methods. Typically, many integrals must be computed. They are divided up into different classes, on the basis of the required accuracy and spatial extent. Ideally, each batch should be integrated using the minimal set of integration points that at the same time guarantees the required precision. Currently used quadrature schemes are far from optimal in this sense, and we are now developing new algorithms. They are designed to be flexible, such that given the range of functions to be integrated, and the required precision, the integration is performed as economically as possible with error bounds within specification. A standard approach is to partition space into a set of regions, where each region is integrated using a spherically polar grid. This article presents a radial quadrature which allows error control, uniform error distribution and uniform error reduction with increased number of radial grid points. A relative error less than 10⁻¹⁴ for all s-type Gaussian integrands with an exponent range of 14 orders of magnitude is achieved with about 200 grid points. Higher angular l quantum numbers, lower precision or narrower exponent ranges require fewer points. The quadrature also allows controlled pruning of the angular grid in the vicinity of the nuclei. Received: 30 August 2000 / Accepted: 21 December 2000 / Published online: 3 April 2001     

A Quadrature Formula Based On Sampling In Meyer Wavelet Subspaces

In this paper we discuss a weighted trapezoidal rule based on sampling in Meyer wavelet subspaces. For a wide class of functions, we obtain convergence and error bounds. Some examples are given to construct sampling functions.     

Quantum Statistical Behaviors of Interaction of an Atomic Bose-Einstein Condensate with Laser

We have investigated quantum statistical behaviors of photons and atoms in interaction of an atomic Bose Einstein condensate with quantized laser field. When the quantized laser field is initially prepared in a superposition state which exhibits holes in its photon-number distribution, while the atomic field is initially in a Fock state, it is found that there is energy exchange between photons and atoms. For the input and output states, the photons and atoms may exhibit the sub-Poissonian distribution. The input and output laser fields may exhibit quadrature squeezing, but for the atomic field, only the output state exhibits quadrature squeezing. It is shown that there exists the violation of the Cauchy-Schwartz inequality, which means that the correlation between photons and atoms is nonclassical.``     

一种9.8-mW 1.2-GHz CMOS 低噪声正交输出频率综合器

实现了一种基于标准0.18µm CMOS工艺的应用于北斗导航射频接收机的1.2GHz频率综合器。在频率综合器中采用了一种基于分布式偏置技术实现的低噪声高线性LC压控振荡器和一种基于源极耦合逻辑的高速低开关噪声正交输出二分频器,集成了基于与非触发器结构的高速8/9双模预分频器、无死区效应的延迟可编程的鉴频鉴相器和电流可编程的电荷泵。该频率综合器的输出频率范围从1.05到1.30GHz。当输出频率为1.21GHz 时,在100-kHz和1-MHz的频偏处相位噪声分别为-98.53dBc/Hz和-121.92dBc/Hz。工作电压为1.8V时,不包括输出Buffer的核心电路功耗为9.8mW。北斗射频接收机整体芯片面积为2.41.6 mm2。