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用改进的快速傅里叶变换法评估一维标准样板线节距数据 被引量:1
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作者 李同保 +3 位作者 雷李华 李源 蔡潇雨 马艳 《光学精密工程》 EI CAS CSCD 北大核心 2015年第1期230-236,共7页
由于利用快速傅里叶变换(FFT)法定量测量标准样板的平均节距时会因为频谱分辨率Δf有限而在数据分析过程中丢失信息,故本文对常用的FFT法进行了改进。首先在FFT的频谱中得到最大振幅值对应的频率分量fmax,使用二分法缩小fmax附近的频率... 由于利用快速傅里叶变换(FFT)法定量测量标准样板的平均节距时会因为频谱分辨率Δf有限而在数据分析过程中丢失信息,故本文对常用的FFT法进行了改进。首先在FFT的频谱中得到最大振幅值对应的频率分量fmax,使用二分法缩小fmax附近的频率范围;然后利用连续傅里叶变换法寻找更大的振幅值与更精确的f′max以求得更接近真实值的线节距。为了验证该方法的可行性,利用Matlab软件仿真被测标准样板(TGD1)的轮廓图,比较了FFT与改进后的FFT对不同扫描长度下数据的评估结果,并展示了改进FFT法评估时部分数据的运算过程。同时,通过计量型原子力显微镜实测20μm×2μm内的TGD1形貌。两种评估法下的数据比对结果显示:改进FFT评估后的线节距为(277.84±0.39)nm,符合标称值(278±1)nm,验证了改进后FFT方法对线节距求解的准确性与合理性。 展开更多
关键词 快速傅里叶变换法 线节距 一维线间隔标准样板 微纳米计量
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Fabrication and measurement of traceable pitch standard with a big area at trans-scale 被引量:5
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作者 邓晓 李同保 +4 位作者 雷李华 马艳 马蕊 李源 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第9期143-147,共5页
Atom lithography with chromium can be utilized to fabricate a pitch standard, which is chrectly traceable to me wavelength of the laser standing waves. The result of a calibrated commercial AFM measurement demonstrate... Atom lithography with chromium can be utilized to fabricate a pitch standard, which is chrectly traceable to me wavelength of the laser standing waves. The result of a calibrated commercial AFM measurement demonstrates that the pitch standard is (212.8±0.1) nm with a peak-to-valley-height (PTVH) better than 20 nm. The measurement results show the high period accuracy of traceability with the standing laser wavelength (λ/2 = 212.78 nm). The Cr nano-grating covers a 1000μm×500 μm area, with a PTVH better than 10 nm. The feature width broadening of the Cr nanostructure has been experimentally observed along the direction of the standing waves. The PTVH along the Gaussian laser direction is similar to a Gaussian distribution. Highly uniform periodic nanostructures with a big area at the millimeter scale, and the surface growth uniformity of the Cr nano-grating, show its great potential in the application of a traceable pitch standard at trans-scales. 展开更多
关键词 atom lithography nano-scale metrology standard TRACEABILITY
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Nano-Traceability Study of a Cr Standard Grating Fabricated by Laser-Focused Atomic Deposition
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作者 雷李华 李源 +4 位作者 范国芳 邓晓 蔡潇雨 李同保 《Chinese Physics Letters》 SCIE CAS CSCD 2014年第7期46-49,共4页
A dimensional artifact is developed, which is a chromium (Cr) deposition grating fabricated by a laser-focused atomic deposition technique. The mean pitch of the grating is measured by using a metrological atomic fo... A dimensional artifact is developed, which is a chromium (Cr) deposition grating fabricated by a laser-focused atomic deposition technique. The mean pitch of the grating is measured by using a metrological atomic force microscope with a large range, where a series of reference signs have been performed to locate the deposition area. Cosine error of the measurement result is analyzed and eliminated by the iterative angle calibration. The measurement result shows that the mean pitch of the grating is 212.66 ±0.02nm, which is very close to half of the standing laser wavelength (λ = 425.55 nm). This means that the grating has traceability with high accuracy and can substitute the laser interference technology for instrument calibration. Moreover, using the Cr deposition grating as a nano standard can shorten the traceability chain and improve the practical application. 展开更多
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麻花辫的故事
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作者 《文学港》 2005年第2期185-185,共1页
头发——简单,微不足道。可是,头发一旦长在女孩的头上时,头发就不只是头发,它更是件饰品。天生就有打扮特权的女孩们,自然会使那头乌黑的秀发展示出独特的魅力。如今,有一种轻薄细长、斜披式的刘海逐渐成为潮流,特别为女孩所喜。这种... 头发——简单,微不足道。可是,头发一旦长在女孩的头上时,头发就不只是头发,它更是件饰品。天生就有打扮特权的女孩们,自然会使那头乌黑的秀发展示出独特的魅力。如今,有一种轻薄细长、斜披式的刘海逐渐成为潮流,特别为女孩所喜。这种刘海有着时尚的美。但时尚毕竟太抽象了,让人难以把握。于是,时尚的美总让人觉得浮华。无意间,一种已逝的单纯的感觉油然而生,两根可爱的麻花辫传递着这种感觉,让我感到真切的欣喜,遥远的心痛。 展开更多
关键词 麻花 头发 童年回忆 心痛 女生 时尚 故事 印记 摆动 天使
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