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Analysis of Depth of View and Focus of Digital Holographic Imaging System
数字全息成像系统的景深和焦深分析

王华英,,赵洁,王广俊,王大勇
光子学报 , 2008,
Abstract: Based on the Fresnel diffraction theory, the depth of view (DOV) and the depth of focus (DOF) of the digital holographic system are analyzed. The approximate expressions of the DOF of the different holographic recording configurations are deduced. The results show that the DOV and DOF of the digital holographic imaging system are related to the optical wavelength and the numerical aperture of the CCD camera and to the offset of the reference light wave. With both the same recording distance and parameter of CCD, the DOF of the off-axis Fresnel holographic system is found larger than that of the in-line Fresnel digital holographic system. The DOF of off-axis lensless Fourier digital holographic system with symmetrical offset of reference wave is slightly smaller than that of the system without symmetrical offset. Moreover, in digital holographic microscopy, the DOF of off-axis lensless Fourier digital holographic system is larger than that of in-line Fresnel digital holographic system. The computer simulation results confirm the validity of the theoretical analysis.
预放大数字全息显微系统的特点
王华英,刘飞飞,,廖薇,于梦杰,刘佐强,马彦晓
强激光与粒子束 , 2013,
Abstract: ?为了提高预放大数字全息显微系统的成像质量,采用理论分析与实验验证相结合的方法,分别对采用平面及球面参考光记录的预放大数字全息显微系统进行了研究和比较。结果表明:在通常的实验条件下,系统的横向分辨力主要取决于显微物镜的成像分辨力;记录距离较小时,两种系统的横向分辨力均随着记录距离的增大略有降低;但当记录距离较大时,球面参考光预放大数字全息系统的横向分辨力降低得更为明显,即平面参考光预放大数字全息显微系统较为优越;在记录距离为0的情况下,即像面数字全息成像情况下,两种系统的再现像均具有最高的分辨力,在利用普通工业用传感器条件下,横向分辨力远超过了2.19μm,且像质较好。因此,尽可能减小全息图的记录距离,或者采用像面数字全息系统,可以有效提高数字全息系统的成像分辨力。
Optimized digital micro-holographic imaging system
优化的数字全息显微成像系统

Wang Hua-Ying,Liu Fei-Fei,Liao Wei,Song Xiu-Fa,Yu Meng-Jie,Liu Zuo-Qiang,
王华英
,刘飞飞,廖薇,,于梦杰,刘佐强

物理学报 , 2013,
Abstract: Based on the analysis of the recording and reconstructing of hologram and the point spread function of pre-magnification digital micro-holographic system (PMDMHS), the performances of the six common PMDMHSs are compared in imaging resolution, imaging quality and conveniences, for the first time to our knowledge. The results show that the digital image-plane holography (DIPH) has the highest imaging resolution and the best imaging quality; the resolution of DIPH is independent of the photosensitive surface size of the recording device; this system can completely record the information about the object transmitted through the micro-objective (MO); it is not needed to consider the size of illuminated region of object. Moreover, the reconstruction process of DIPH is very simple. DIPH is an optimized digital holographic imaging system. The DIPH with equal curvature of reference wavefront and object wavefront is very conducive to phase unwrapping and phase aberration compensation; therefore DIPH is more suitable for phase microscopy. The experimental results demonstrate the validation of the theoretical analysis.
Focal depth of digital lensless Fourier transform micro-holographic system
无透镜傅里叶变换显微数字全息成像系统的焦深

Wang Hua-Ying,Zhang Zhi-Hui,Liao Wei,Song Xiu-F,Guo Zhong-Jia,Liu Fei-Fei,
王华英
,张志会,廖薇,,郭中甲,刘飞飞

物理学报 , 2012,
Abstract: Based on the Strehl criterion of coherent lens imaging system, the focal depth (FD) of lensless Fourier digital micro-holographic system is deduced. The FD expressions of the holographic systems with symmetrical and unsymmetrical reference point sources are obtained. The results show that the FD of lensless Fourier digital micro-holographic system is dependent not only on the optical wavelength and the numerical aperture of the recording system but also on the offset of the reference optical source, which is different from the FD of lensless Fourier digital micro-holographic system. The validities of the theoretical analysis are demonstrated by the computer simulations and experiments.
基于无监督学习的专业领域分词歧义消解方法
驰*,
计算机应用 , 2013,
Abstract: ?中文自然语言处理中专业领域分词的难度远远高于通用领域。特别是在专业领域的分词歧义方面,一直没有找到有效的解决方法。针对该问题提出基于无监督学习的专业领域分词歧义消解方法。以测试语料自身的字符串频次信息、互信息、边界熵信息为分词歧义的评价标准,独立、组合地使用这三种信息解决分词歧义问题。实验结果显示该方法可以有效消解专业领域的分词歧义,并明显提高分词效果。
海平面长期变化对推算多年一遇极值水位的影响
于宜,俞聿
华东政法大学学报 , 2003,
Abstract: 利用乳山口24a的年极值高、低水位和年平均海平面,分析讨论了平均海平面长期变化对推算多年一遇极值水位的影响.同时讨论了消除平均海平面中长期变化的途径.比较了消除平均海平面长期变化和保留这种变化情况下推算出的两种多年一遇极值水位,可以发现,对多年一遇高水位来说,保留平均海平面长期变化所得结果高于消除了的,而对多年一遇低水位而言,情况正好相反.
渤海天文-风暴潮数值模拟和一种多年一遇极值水位的计算方法
于宜,俞聿
华东政法大学学报 , 2003,
Abstract: 在渤海选用了82个强天气过程,利用三维模式模拟了海区的天文-风暴潮,模式经实测资料检验,获得了较满意的模拟结果。根据渤海沿岸主要验潮站观测年极值高(低)水位和年极值风增(减)水所得到的多年一遇高(低)水位和多年一遇风增(减)水,以及天文最高(最低)潮位,建立了由多年一遇风增(减)水和天文最高(最低)潮位的线性组合计算多年一遇高(低)水位的计算公式,并以此公式推算了渤海海区5个典型地区的多年一遇高(低)水位,供海洋工程设计时使用。
大缸径双伸缩立柱内加载液压试验系统设计
王万,
煤炭科学技术 , 2012,
Abstract: 为解决500mm缸径立柱的日常厂内试验和出厂试验问题,介绍了一种大缸径双伸缩立柱卧式内加载试验台。该试验台的增压加载系统,能达到大于乳化液泵压的内加载试验压力,完成被试缸的耐压性能和拉压性能等试验;根据试验系统使用的液压元件,利用1对液压缸首尾对接,建立了Simhydraulics模型,完成了仿真和实测支撑性能的负载效率曲线绘制;采用VisualC#语言编制数据采集程序,按试验步骤自动采集试验系统的试验数据和自动输出试验报表数据文件等,研究结果表明,该试验系统能满足大缸径立柱检验需求,并可大幅提高生产效率。
考虑损伤门槛的统计损伤本构模型研究
,
煤田地质与勘探 , 2007,
Abstract: 在统计损伤理论的基础上,从统计损伤本构模型的一般性公式出发,考虑到岩石的受力状态,提出统计损伤本构模型应考虑损伤门槛的影响,建立了考虑损伤门槛的统计损伤本构方程。以石膏角砾岩的常规三轴试验结果作为实例,进行了验证。理论计算结果与试验结果对比表明,考虑损伤门槛的统计损伤本构模型是更加合理的。
分级加载下岩土流变的神经网络模型
,
岩土力学 , 2006,
Abstract: 针对分级加载下用线性叠加原理来描述岩土非线性流变存在的问题,采用人工神经网络方法代替传统数学力学方法,建立了分级加载下岩土流变的神经网络模型,并且对具体岩石的蠕变试验曲线进行了模拟。结果表明,该模型能较好地描述岩土的非线性流变,具有较强的泛化能力,为研究岩土的流变特性特别是分级加载下岩土的非线性流变特性提供了一条新途径。
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