共查询到20条相似文献,搜索用时 11 毫秒
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提出一种基于粒子群优化算法实现的硅钢涂层厚度近红外光谱检测新方法.首先,采用近红外光谱仪采集获得了硅钢表面绝缘涂层的近红外光谱,然后,采用离散粒子群算法筛选出近红外光谱数据的最佳波长变量并组成新的光谱数据,最后,建立涂层厚度的核偏最小二乘定量分析模型.实验显示,所建定最分析模型对检验样本分析的绝对误差范围为-0.12~... 相似文献
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Kazuhiko Ishikawa Hitomi Yamano Katsuhiko Asada Koichi Iwata Masahiro Ueda 《Optics and Lasers in Engineering》2004,41(5):731
An ingenious optical method was developed for measuring the thickness of a coating directly and in real time at a measuring frequency of a few tens of Hz. The basic optical arrangement is very simple, and consists of a semiconductor laser, two cylindrical lenses, and a silicon photodiode array or CCD camera. The range of measurable thickness is roughly between λ and 100λ, where λ is a wavelength of the laser light, and its measuring error is a few percent. The previously developed method for measuring the thin film in air, which can be analyzed theoretically, can also be applied for estimating the thickness of a coating on the substratum within an error of 2%. 相似文献
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针对常用电阻应变片法的点测结果不易反映构件表面应变场分布的问题,将光弹性贴片方法应用于材料表面应变场测量。制作了光弹性贴片,并标定光弹性贴片的材料条纹值,通过几种典型形状光弹性贴片试件的加载实验掌握应力场分布的条纹图像判读方法。开展光弹性贴片在简支钢梁的应变场测量应用,在薄弱点位置光弹性贴片法相比电阻应变片法应变值偏差在5%以内。对C30混凝土试块进行4.4 MPa~39.6 MPa的应力加载过程中,有效监测到混凝土表面裂缝产生、稳定扩展及失稳破坏过程中的条纹图像变化过程。实验表明,光弹性贴片方法可以直观可靠地测量金属及混凝土的表面应力场变化。 相似文献
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积分光谱法测量塑料薄膜厚度研究 总被引:1,自引:0,他引:1
在谱带朗伯定律概念的基础上,通过分析光束在透过塑料薄膜时光强所发生的变化,提出了谱带积分透过率定义并建立基于谱带积分透过率的薄膜厚度测量模型。采用不同厚度的聚丙烯薄膜作为实验对象,使用光谱仪测量了其光谱透过率。按上述模型拟合了薄膜厚度与谱带积分透过率关系式。使用500K理想黑体,分析了基于此方法研制新型宽谱带塑料薄膜厚度在线检测装置的可行性。实验结果表明:使用积分光谱法可以较高精度的测量塑料薄膜厚度。基于此方法研制的塑料薄膜厚度在线检测装置,有望解决使用双单色光对比法测薄膜厚度时存在的准确性低、通用性差的问题。 相似文献
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薄膜样品在实验研究领域要求样品的厚度测量精度非常高,但由于样品质量小,采用称重的方法,测量精度较差。在北京同步辐射装置的中能(4B7A)和低能(4B7B)束线上(光源能区为0.1~6.0 keV,能量分辨大于1 000),采用材料对单能光子的透过率来确定样品的质量厚度,通过不同能点的测量值进行不确定度分析,提高测量精度,降低不确定度。利用该方法开展了复合样品厚度的测量方法研究,给出了有CH衬底的薄膜样品的厚度,通过不确定度分析得出,薄膜样品厚度的测量不确定度小于1%。 相似文献
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薄膜样品在实验研究领域要求样品的厚度测量精度非常高,但由于样品质量小,采用称重的方法,测量精度较差。在北京同步辐射装置的中能(4B7A)和低能(4B7B)束线上(光源能区为0.1~6.0 keV,能量分辨大于1 000),采用材料对单能光子的透过率来确定样品的质量厚度,通过不同能点的测量值进行不确定度分析,提高测量精度,降低不确定度。利用该方法开展了复合样品厚度的测量方法研究,给出了有CH衬底的薄膜样品的厚度,通过不确定度分析得出,薄膜样品厚度的测量不确定度小于1%。 相似文献
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为了快速、准确得到纳米薄膜厚度,采用Kiessig厚度干涉条纹计算薄膜厚度的线性拟合公式,计算了不同系列厚度(10~120 nm)的二氧化硅薄膜。薄膜样品采用热原子层沉积法(T-ALD)制备,薄膜厚度使用掠入射X射线反射(GIXRR)技术表征,基于GIXRR得到的反射率曲线系统讨论了线性拟合公式计算薄膜厚度的步骤及影响因素,同时使用XRR专业处理软件GlobalFit2.0比较了两种方法得到的膜厚,最后提出一种计算薄膜厚度的新方法-经验曲线法。结果表明:峰位级数对线性拟合厚度产生主要影响,峰位级数增加,厚度增大;峰位对应反射角同样对线性拟合厚度有较大影响,表现为干涉条纹周期增大,厚度减小。但峰位级数及其对应反射角在拟合薄膜厚度过程中引入的误差可进一步通过试差法,临界角与干涉条纹周期的校准来减小。对任意厚度的同一样品,线性拟合和软件拟合两种方法得到的薄膜厚度具有一致性,厚度偏差均小于0.1 nm,表明线性拟合方法的准确性。在厚度准确定值的基础上提出薄膜厚度与干涉条纹周期的经验关系曲线,通过该曲线,可直接使用干涉条纹周期计算薄膜厚度,此方法不仅省略了线性拟合过程中确定峰位级数及其对应反射角的繁琐步骤,而且避免了软件拟合过程中复杂模型的建立,对快速、准确获得薄膜厚度信息具有重要的意义。 相似文献
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This paper studies the absolute thickness measurement of pyrolytic graphite spheroids (GSs) by using STEM-EELS mode with log-ratio method and Kramers-Kroning (K-K) method, taking the measured thickness from TEM image as reference that is the diameter of GSs ranging from 60 to 250 nm. The effect of collection semi-angle (β) on thickness measurement has been investigated. It is found that in general the thickness obtained by K-K analysis with surface effect corrected shows the best accuracy, followed by K-K sum rule and then log-ratio method for the three different collection semi-angles of 12.4, 17.3 and 21.1 mrad applied. Of these angles, the smallest one gives an overestimated result and the largest one gives an underestimated result, whereas between the two, the angle of 17.3 mrad that is about 2x convergence semi-angle (9.0 mrad) is identified as more appropriate for K-K analysis. The surface-scattering correction, inelastic mean free path of GS and effect of refractive index n on thickness measurement for different β angles are also investigated. Moreover, the optical property deduced from the data collected at the center of graphite spheroid, which is related to its microstructure, is characterized by K-K analysis. 相似文献
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The super-hydrophobic coating was successfully fabricated on the surface of magnesium alloy AZ31 by chemical etching and surface modification. The surface morphologies, compositions, wettability and corrosion resistance of the coating were investigated with SEM, XPS, contact angle measurement and electrochemical method, respectively. It shows that the rough and porous micro-nano-structure was presented on the surface of magnesium alloy, and the contact angle could reach up to 157.3 ± 0.5° with sliding angle smaller than 10°. The super-hydrophobic coating showed a long service life. The results of electrochemical measurements showed that anticorrosion property of magnesium alloy was improved. The super-hydrophobic phenomenon of the prepared surface was analyzed with Cassie theory, and it finds that only about 10% of the water surface is contacted with the metal substrate and the rest 90% is contacted with the air cushion. 相似文献
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Coating thickness affects surface stress measurement of brush electro-plating nickel coating using Rayleigh wave approach 总被引:1,自引:0,他引:1
A surface ultrasonic wave approach was presented for measuring surface stress of brush electro-plating nickel coating specimen, and the influence of coating thickness on surface stress measurement was discussed. In this research, two Rayleigh wave transducers with 5 MHz frequency were employed to collect Rayleigh wave signals of coating specimen with different static tensile stresses and different coating thickness. The difference in time of flight between two Rayleigh wave signals was determined based on normalized cross correlation function. The influence of stress on propagation velocity of Rayleigh wave and the relationship between the difference in time of flight and tensile stress that corresponded to different coating thickness were discussed. Results indicate that inhomogeneous deformation of coating affects the relationship between the difference in time of flight and tensile stress, velocity of Rayleigh wave propagating in coating specimen increases with coating thickness increasing, and the variation rate reduces of difference in time of flight with tensile stress increasing as coating thickness increases. 相似文献
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全息干板膜的厚度是全息干板的重要参数之一。使用迈克尔逊干涉仪和白光光源对2种全息干板膜厚度进行测量,并对测量结果误差进行分析,给出了测量误差与膜厚及折射率之间的关系以及此方法的适用范围。研究结果表明:在膜厚从8μm增至41μm的过程中,测量结果的绝对误差≤2μm且变化很小,相对误差则从14.1%降到了2.2%。随着膜厚的增加,相对误差明显降低;折射率n也参与了误差传递,其值与测量误差呈类似反比关系;当n值在1.5附近时,为保证测量的准确性,所测膜厚≥40μm。最后指出,迈克尔逊干涉仪在测量全息干板膜等较厚的薄膜时,具有测量范围大,结果较准确等优点。 相似文献
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为减少坦克在实战中的红外辐射, 分析了坦克炮慢射后的辐射特征, 针对其炮管所辐射的特征波长在8-12 μm的电磁波,选用常见的SiO2和Si为介质, 并在考虑各自色散关系的基础上, 设计了具有光子晶体结构的防辐射涂层. 数值计算表明: 当两介质各取4层, 其几何厚度分别取1330和825 nm时,在8-12 μm 的范围内有一个严格的带隙. 当两介质的几何厚度增加, 带隙红移, 宽度增加, 反之亦然. 只要两介质的几何厚度变化不同时超过10%, 原带隙总是存在. 当介质层数取7-8时, 涂层在上述波长范围内的严格带隙已形成, 介质层数再增加, 带隙没有实质性的变化. 带隙结构对入射角的变化并不敏感. 相似文献
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铁基合金锡、锌镀层厚度的X射线荧光光谱快速测定 总被引:4,自引:0,他引:4
铁基合金锡、锌镀层的厚度通常采用湿法化学法分析,本文根据在临界厚度以内,X射线荧光强度与样品厚度有关的原理,用波长色散X射线荧光光谱仪测定镀锡板(俗称马口铁)、镀锌板中的SnKα_1、ZnKα_(1.2)、FeKα_(1.2)等特征谱线的强度,然后用线性回归和非线性拟合等方法获得谱线强度和镀层厚度之间的数学关系。本法测量锡、锌镀层厚度准确、快速、简便,所得结果可与湿法化学分析结果相比。 相似文献
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透射式微型X射线管是能量色散X射线荧光分析中的主要激发源,在能量色散X射线荧光分析中希望得到谱分布较为单一的X射线管输出谱。采用MC方法,研究了透射式微型X射线管在不同目标靶厚度的情况下输出谱的特征,通过低谱段(<5 keV)和高能谱段(5~50 keV)的分析比较,高能谱段计数随厚度加大先增加而后减小,低能谱段计数则随厚度增加减小,增加目标靶厚度可以有效抑制低能谱段。在入射电子能量为50 keV和目标靶为4 Ag的条件下,X射线管输出能谱具有较高的高能谱段注量,同时有效压制低能谱段注量,适合能量色散X射线荧光分析中使用。 相似文献
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本文首先介绍了激光武器在未来战争中的突出地位和发展现状,阐明了高能激光束与目标材料相互作用时的热效应毁伤机理;总结了基于等离子喷涂的反射型激光防护涂层的研究进展,包括等离子喷涂金属涂层和陶瓷涂层的研究进展、以及各自的技术特点和防护效果,为高能激光防护领域的研究提供了借鉴。研究结果表明,控制金属涂层在激光辐照过程中的氧化现象能有效地提高涂层的激光防护性能,同时具有优异反射性能的新型陶瓷涂层在高能激光防护领域中有较好的发展前景。 相似文献