全文获取类型
收费全文 | 83篇 |
免费 | 20篇 |
国内免费 | 12篇 |
专业分类
力学 | 16篇 |
物理学 | 99篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 1篇 |
2020年 | 2篇 |
2017年 | 1篇 |
2016年 | 2篇 |
2015年 | 2篇 |
2014年 | 4篇 |
2013年 | 3篇 |
2012年 | 10篇 |
2011年 | 7篇 |
2010年 | 4篇 |
2009年 | 4篇 |
2008年 | 9篇 |
2007年 | 10篇 |
2006年 | 12篇 |
2005年 | 4篇 |
2004年 | 8篇 |
2003年 | 6篇 |
2002年 | 3篇 |
2001年 | 1篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1997年 | 1篇 |
1996年 | 5篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1991年 | 2篇 |
1989年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有115条查询结果,搜索用时 31 毫秒
31.
Nonlinear effect of the structured light profilometry in the phase-shifting method and error correction 下载免费PDF全文
Digital structured light (SL) profilometry is increasingly used in three-dimensional (3D) measurement technology. However, the nonlinearity of the off-the-shelf projectors and cameras seriously reduces the measurement accuracy. In this paper, first, we review the nonlinear effects of the projector-camera system in the phase-shifting structured light depth measurement method. We show that high order harmonic wave components lead to phase error in the phase-shifting method. Then a practical method based on frequency domain filtering is proposed for nonlinear error reduction. By using this method, the nonlinear calibration of the SL system is not required. Moreover, both the nonlinear effects of the projector and the camera can be effectively reduced. The simulations and experiments have verified our nonlinear correction method. 相似文献
32.
33.
M. B. Klein 《International Journal of Infrared and Millimeter Waves》1981,2(2):239-246
We have measured electro-optic coefficients at 94 GHz for several orientations in LiNbO3 and LiTaO3. These coefficients are considerably enhanced over their values in the visible, due to contributions from lattice vibrations. A scaling law is developed which allows the calculation of these coefficients in terms of the linear susceptibility. The phase shifting performance of a number of promising materials is discussed. 相似文献
34.
L. Y. Zhu X. F. Huang W. B. Fan X. W. Wang W. Li L. Wang K. J. Chen 《Superlattices and Microstructures》2002,31(6):285
We employed atomic force microscopy, cross-section transmission electron microscopy and high-resolution electron microscopy to investigate the microstructures and surface morphology of laser interference crystallized a-Si : H/a-SiNx : H superlattices. The experimental results show that Si nanocrystallites (nc-Si) are formed within the initial a-Si : H sublayers and are patterned in certain regions with the same periodicity of 2.0 μ m as the phase-shifting mask grating. The size of nc-Si is limited by adjacent a-SiN x: H sublayers due to the constrained crystallization effect so it is possible to use this crystallization method to get a three-dimensional ordered nc-Si array. 相似文献
35.
任意相移阴影叠栅相位解调技术的研究 总被引:1,自引:1,他引:0
结合时域和频域干涉图分析方法,提出一种任意相移阴影叠栅条纹图相位解调技术,降低了干涉图在采样过程中对相移量的严格标定要求,补偿了相移阴影叠栅技术固有的相移不匀误差。使用空域技术确定采样干涉图的正交信号,进而得到了采样干涉图的相移量,然后运用任意相移相位提取算法搜索测量相位信息。实验证明此方法简单方便、求解迅速,且优于典型的相移算法,其测量误差的标准差不超过3×10-3 mm,该方法为提高相移阴影叠栅技术的测量精度提供了有效手段。 相似文献
36.
介绍了基于计算机控制的频闪显微干涉测量技术,实现了对MEMS微变形镜的表面形貌、离面变形、静态电压-位移曲线和谐振频率的测量。采用频闪成像、计算机微视觉技术以及基于最小二乘曲面拟合法的亚像素定位技术实现了对平面内微位移的测量;利用频闪成像以及5步相移干涉技术实现了对干涉相位的提取,建立了适合于MEMS微变形镜特性测试的相位解缠算法,恢复了代表被测物体表面形貌的真实相位,实现了微变形镜静动态特性的测试。测试结果表明:频闪显微相移干涉测量技术具有测量速度快、精度高、易实现自动控制等特点。 相似文献
37.
38.
We report our experimental results of phase-shifting interferometry with an iterative least-squares fitting technique to estimate both the wave front phases and the phase shifts. The method allows phase retrieval from phase-shifting interferograms even though the calibration data of the phase shifter is unknown. The algorithm is used to analyze two sets of experimental interferograms. One records by moving a piezoelectric transducer shifter randomly and therefore has embedded random phase shifter errors, and the other samples the interference movie recorded by a video recorder while driving a stepping motor and therefore has embedded random intensity noises. The results are comparable with that of the conventional M-frame algorithm. Investigation of the effects of the intensity noises and phase shift errors shows the algorithm to perform well in both. Problems such as convergence, unique solution and reliability are also discussed. 相似文献
39.
相移全息CT技术测量双烛火焰温度场 总被引:2,自引:0,他引:2
提出了相移全息CT技术,实验中采用双参考光相移方法在再现阶段引入相移,重建了双烛火焰层面的温度场,结果表明,这一技术能够快速,高精度地获取各个投影响方向上的位相分布,重建出令人满意的结果。 相似文献
40.