排序方式: 共有57条查询结果,搜索用时 15 毫秒
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数字图像相关方法中散斑图的质量评价研究 总被引:4,自引:0,他引:4
在利用数字图像相关方法测量物体表面变形时,被测物体表面必需覆盖有灰度随机分布的散斑场,该散斑场作为试件表面变形信息的载体随试件一起变形。在实际情况下,不同的散斑场会显示出完全不同的灰度分布特征,并对数字图像相关方法的测量结果有着重要影响。因此如何定量评价散斑图的优劣是数字图像相关方法中一个重要的基本问题,也是该方法的使用者非常关心的问题。基于最近数字图像相关方法基本理论研究的进展,本文提出平均灰度梯度这一新参数用于散斑图质量的评价。为证实该参数的有效性,本文对五幅明显不同的散斑图进行了精确平移,并将数字图像相关方法测量的位移与预加的平移量进行比较,分析了位移测量结果的均值误差和标准差。结果显示位移测量结果的均值误差和标准差均与散斑图的平均灰度梯度有关,一个好的散斑图应该具有较大的平均灰度梯度。 相似文献
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自动网格法在轮胎橡胶力学行为测试中的应用 总被引:7,自引:1,他引:7
本文利用自动网格法光学测量技术的非接触、高精度以及可以获得全场变形信息等优点,建立了一套包含图像采集功能的载荷-变形同步测试,实验轮胎橡胶单向拉伸较大变形力学行为的测试。试验结果表明自动网格法适用于轮胎橡胶等软试件较大变形力学行为的测试,同时也验证了加和卸载过程中,胎面碳黑填充橡胶(以下简称胎面胶)具有明显的迟滞效应、Mullins效应以及残余变形;而纵横向平均应变的数据则有力的证明了在单向拉伸的较大变形范围内,胎面胶是可压缩的,且体积比随轴向拉伸应变增大而逐渐增大。 相似文献
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原子反射镜是人们从事原子光学实验研究的重要器件之一.本文将简单综述采用冷原子磁、光操控技术发展起来的诸如消逝波原子反射镜、半高斯光束原子反射镜、周期性磁化的磁带反射镜、周期性排列的永久磁铁反射镜和载流导线磁反射镜等各种原子反射镜的基本原理、实验方案及其最新进展,并就原子反射镜在原子光学实验中的应用作一简单介绍. 相似文献
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This paper proposes a scheme to guide cold polar molecules by using a single charged
wire half embanked in an insulating substrate and a homogeneous bias
electric field, which is generated by a plate capacitor composed of two
infinite parallel metal plates. The spatial distributions of the
electrostatic field produced by the combination of the charged wire and the
plate capacitor and the corresponding Stark potentials (including dipole
forces) for metastable CO molecules are calculated, the relationships
between the electric field and the parameters of our charged-wire layout are
analysed.
It also studies the influences of the insulator on the electric field
distribution and the discharge effect. This study shows that the proposed
scheme can be used to guide cold polar molecules in the weak-field --
seeking
states, and to form various molecule-optical elements, such as molecular
funnel, molecular beam-splitters and molecule interferometer, even to
construct a variety of integrated molecule-optical elements and their
molecule chips. 相似文献
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Adiabatic cooling for cold polar molecules on a chip using a controllable high-efficiency electrostatic surface trap 下载免费PDF全文
We propose a controllable high-efficiency electrostatic surface trap for cold polar molecules on a chip by using two insulator-embedded charged rings and a grounded conductor plate. We calculate Stark energy structure pattern of ND3 molecules in an external electric field using the method of matrix diagonalization. We analyze how the voltages that are applied to the ring electrodes affect the depth of the efficient well and the controllability of the distance between the trap center and the surface of the chip. To obtain a better understanding, we simulate the dynamical loading and trapping processes of ND3 molecules in a |J, KM = |1,-1 state by using classical Monte–Carlo method. Our study shows that the loading efficiency of our trap can reach ~ 88%. Finally, we study the adiabatic cooling of cold molecules in our surface trap by linearly lowering the potential-well depth(i.e., lowering the trapping voltage), and find that the temperature of the trapped ND3 molecules can be adiabatically cooled from 34.5 m K to ~ 5.8 m K when the trapping voltage is reduced from-35 k V to-3 k V. 相似文献
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Electrostatic surface trap for cold polar molecules on a chipElectrostatic surface trap for cold polar molecules on a chipElectrostatic surface trap for cold polar molecules on a chip 下载免费PDF全文
We propose a simple scheme for trapping cold polar molecules in low-field seeking states on the surface of a chip by using a grounded metal plate and two finite-length charged wires that half embanked in an insulating suhstrate, calculate the electric field distributions generated by our charged-wire layout in free space and the corresponding Stark potentials for ND3 molecules, and analyze the dependence of the trapping center position on the geometric parameters. Moreover, the loading and trapping processes of cold ND3 molecules are studied by using the Monte Carlo method. Our study shows that the loading efficiency of the trap scheme can reach 11.5%, and the corresponding temperature of the trapped cold molecules is about 26.4 inK. 相似文献
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