Application of rigorous coupled-wave theory on quality analysis of natural jadeite

In order to make more available methods for natural jadeite quality evaluation,this study applied rigorous coupled wave theory to calculate and simulate the reflection characteristics of various natural jadeites,and establish evaluation standard based on the relationship between refractive index and reflectivity and responses of reflection efficiency to refractive index,grating thickness and incident angles,etc.The results suggest that reflection efficiency varies significantly as a function of the natural jadeite quality,which can provide a new method to evaluate natural jadeite.

A coin-tap method of composite materials non-destructive testing based on improved grey clustering

Aiming at the problems of low reliability and complex operation of traditional coin-tap test of composite material,this paper introduces the grey system theory and achieves better performance.The response signals of coin-tap are classified through the grey clustering based on relation analysis,and corresponding improvements are made to the calculation method of the relation degree of nearness.First,the time history of acceleration is taken as the system behavior sequence.The improved correlation calculation method is used to solve the relation degree of nearness between the sequences,and the matrix of degree of grey relation is constructed based on this.Then,the sequence groups are summarized through the matrix,and the response signals of coin-tap are qualitatively classified according to the location of the reference sequence.Finally,the defect detection of composite materials is completed without pre-testing.The test results show that the accuracy of the coin-tap test based on improved grey clustering reaches 100%,which simplifies the operation steps while ensuring the reliability of the coin-tap test results.

Sugar Cane （Saccharum officinarum L.） Analysis through Biospeckle and Spectroscopy （NIR）

The objective of this paper was to evaluate the sugar and water content in sugar cane samples by means of twonon-destructive techniques in comparison with conventional methods. One non-destructive technique is the Biospeckle, aninteraction between the laser and the biological material which provides information about the material. The other technique is thenear infrared spectroscopy （NIR）. The Biospeckle technique has been constantly used in agricultural engineering. In this paper, therelation between the water and the sugar contents were obtained. The results for the Biospeckle were acquired through the moment ofinertia （MI）. The data acquired through already consolidated methodologies were used to quantify the samples＇ water and sugarcontents, correlating to the spectroscopy results and also to the Biospeckle. It was obtained a high determination coefficient （R^2 =0.9287） between the predicted Brix by the model generated by NIR spectroscopy and Brix measured by refractometer. It was alsopossible to differentiate the water contents of the sugar cane samples both externally lit （husk） and internally lit （cut） by Biospeckleanalysis through the calculation of MI. It is possible to evaluate the water content and the sugar content in samples combiningBiospeckle and NIR spectroscopy, which are non-invasive and non-destructive methods.

Tomatoes Maturation Analysis with Reflectance Spectral Images

The demands for high quality products are increasing in the market, so several tests are performed. These analyses are destructive, time consuming and sometimes expensive. The spectral imaging technique is an alternative that can reduce costs and time and increase the efficiency and cost-effectiveness of these analyses. In this context, the aim of this study was to verify the spectral behavior of the tomato in function of the maturation and its potential use for non-destructive evaluation of food quality. Eighty tomatoes of the Italian group were selected in four stages of maturation （green, pink, light red and red）. Images were collected in wavelengths 480 nm to 710 nm （every 10 nm）. After the images were collected, the fruits were submitted to the physical-chemical analyses. The following parameters were analyzed： color, color index （CI）, pH, soluble solids （SS）, total titratable acidity （TTA） and ratio （SS/TTA）. After characterization the mean spectrum was obtained by the extraction of the spectral characteristics. It was observed that the spectral behavior was the same for all stages of maturation. It was possible to differentiate the green tomatoes in the wavelengths from 520 nm to 560 nm and from 610 nm to 660 nm. These intervals represent the area of reflection of chlorophyll and lycopene, respectively. Near the wavelength 560 nm, the highest absorbance was recorded by ripe tomatoes due to the concentration of lycopene. It is concluded that the best wavelengths for analysis are those in which green has the highest reflectance and it is possible to apply this technique for non-destructive analysis of the maturation of tomatoes.

The non-destructive analysis of ancient jade artifacts unearthed from the Liangzhu sites at Yuhang,Zhejiang

Samples of the jade artifacts unearthed from the Liangzhu sites at Yuhang (Fanshan,Yaoshan, Huiguanshan and Tangshan) of Zhejiang province were described. The chemical composition, phase and jade structure of a hundred and more intact samples were analyzed by the non-destructive techniques of PIXE, XRD and laser Raman spectroscopy. Results showed that the minerals of the jade artifacts mostly belonged to tremolite and tremolite-actinolite. Relationship of the civilization development in the Neolithic age and the application of tremolite type mineral in jade artifacts was discussed. The contents of rare and trace elements in tremolite jade artfacts and in mineral samples were measured for the first time. The possible mineral sources of these tremolite type jade artifacts were discussed.

55 Years of Holographic Non-Destructive Testing and Experimental Stress Analysis:Is there still Progress to be expected?

Holographic methods for non-destructive testing,shape measurement,and experimental stress analysis have shown to be versatile tools for the solution of many inspection problems.Their main advantages are the non-contact nature,the non-destructive and areal working principle,the fast response,high sensitivity,resolution and precision.In contrast to conventional optical techniques such as classical interferometry,the holographic principle of wavefront storage and reconstruction makes it possible to investigate objects with rough surfaces.Consequently,the response of various classes of products on operational or artificial load can be examined very elegantly.The paper looks back to the history of holographic metrology,honors the inventors of the main principles,discusses criteria for the selection of a proper inspection method,and shows exemplary applications.However,the main focus is on modern developments that are inspired by the rapid technological process in sensing technology and digitization,on current applications and future challenges.

Relating estimates of wood properties of birch to stem form, age and species

Birch has long suffered from a lack of active forest management,leading many researchers to use mate-rial without a detailed management history.Data collected from three birch(Betula pendula Roth,B.pubescens Ehrh.)sites in southern Sweden were analyzed using regression analysis to detect any trends or differences in wood proper-ties that could be explained by stand history,tree age and stem form.All sites were genetics trials established in the same way.Estimates of acoustic velocity(AV)from non-destructive testing(NDT)and predicted AV had a higher correlation if data was pooled across sites and other stem form factors were considered.A subsample of stems had radial profiles of X-ray wood density and ring width by year created,and wood density was related to ring number from the pith and ring width.It seemed likely that wood density was negatively related to ring width for both birch species.Linear models had slight improvements if site and species were included,but only the youngest site with trees at age 15 had both birch species.This paper indicated that NDT values need to be considered separately,and any predictive models will likely be improved if they are specific to the site and birch species measured.

激光诱导击穿光谱技术(LIBS)定量分析缅甸翡翠中的镁与钙

激光诱导击穿光谱对于宝玉石的定量分析一直是研究热点和难点,为了拓展激光诱导击穿光谱在宝石学研究与检测领域的应用,采用激光诱导击穿光谱(LIBS)对22个缅甸翡翠样品进行镁、钙含量的测量和分析,选取Ca(315.954 nm)、Mg(285.210 nm)和作为定标分析谱线,以Si(288.170 nm)光谱线作为内标谱线。以15个样品分别绘制出了基于谱线强度和基于谱线积分强度的MgO与CaO内定标曲线,基于谱线强度内定标法分析建立的MgO与CaO拟合曲线的相关系数R^(2)分别为0.904和0.949,以检验集中7个样品检验定标曲线,MgO与CaO的LIBS测量值与参考值的相对偏差分别为9.4%~42.2%、4.1%~55.2%,与样品参考值的偏差分别低于0.47%、0.73%;而基于谱线积分强度内定标法分析建立的MgO与CaO元素拟合曲线的相关系数R^(2)分别为0.947和0.973,以检验集中7个样品检验定标曲线,MgO与CaO的LIBS测量值与参考值的相对偏差分别为3.7%~34.9%、3.8%~37.3%,与样品参考值的偏差分别低于0.56%、0.49%。实验结果表明,基于谱线的积分强度的内定标法提高LIBS检测翡翠中MgO与CaO的精确度。研究表明,LIBS对翡翠样品的定量分析具有可靠的重复性和准确性,在宝石学研究领域具有重要的应用潜力。

硬玉微区显微红外光谱分析

缅甸硬玉的微区显微红外光谱中出现的OH、C—H、C O基团的定量比较分析表明,在不同颜色硬玉中其浓度差异明显;说明硬玉的颜色与物化环境的局部变异密切相关,是在一个复杂的有机与无机的天然环境中形成;在合成不同颜色硬玉时,需与适当的物化环境相匹配,尤其是绿色硬玉,才有利于硬玉的生长。

阴极显微发光下识别翡翠

在阴极发光下翡翠的主要矿物成分硬玉通常发暗—中亮绿—黄绿色光 ;当硬玉成分较纯时发亮紫红色光 ;当硬玉中不含铁而含钙和锰时往往发中—亮紫蓝色光和白色光。在阴极显微镜下翡翠的结构清楚可鉴 ;A、 B、 C货各有其明显的区别特征 ;依据 CL图像能较好地区分翡翠和其它相似玉或仿制品。

硬玉的差热分析和紫外荧光光谱研究

通过对缅甸硬玉的差热分析和紫外荧光光谱研究,发现不同颜色硬玉的紫外荧光谱中的617nm处的谱峰,可能是Cr引起的;对不同颜色硬玉进行的差热分析表明,其熔融温度略有不同,说明其生长环境有一定差异,而硬玉也可能是较好的耐热材料,具一定的开发潜能。

单变量分析方法与多变量分析方法结合激光诱导击穿光谱分析翡翠化学成分的对比

激光诱导击穿光谱（LIBS）是一种原子光谱技术,可以同时快速分析多基质成分样品的化学元素组成,包括气体、液体和固体。然而,由于激光消融的不稳定性、基体效应以及自吸收等原因,LIBS的定量测量分析的能力一直没有得到公认。LIBS结合单变量分析方法与多变量分析方法可以快速分析多基质成分样品的化学元素含量,为了探究哪一种分析方法更适合LIBS定量测量分析翡翠,分别采用单变量和多变量的偏最小二乘法（PLS）分析翡翠样品的LIBS光谱数据并建立模型预测Ca和Al的含量。采用单变量建立模型时,对于Ca元素,校正模型与预测模型的相关系数分别为0.93和0.92,校正模型与预测模型的标准均方根误差分别为1.14和1.43;对于Al元素,校正模型与预测模型的相关系数分别为0.63和0.58,校正模型与预测模型的标准均方根误差分别为3.04和3.59。在建立多变量的偏最小二乘法模型时,使用波长197.33-762.8nm范围的峰值强度与质量分数之间的拟合,对于Ca元素,校正模型与预测模型的相关系数分别为0.97和0.95,校正模型与预测模型的相标准均方根误差分别为0.81和1.08;对于Al元素,校正模型与预测模型的相关系数分别为0.92和0.89,校正模型与预测模型的标准均方根误差分别为1.36和1.79。结果显示偏最小二乘法能够提高LIBS对缅甸翡翠的定量测量分析。

利用X射线衍射测定单斜辉石中硬玉组分含量

硬玉是单斜辉石中十分重要的端元组分,是单斜辉石分类的主要基础。利用x射线衍射分析确定的硬玉组分含量计算式为Jd(％)=[A-2.235]×25.741,其中Jd为硬玉组分百分含量,A为2—Theta角为30°(d=2.97)时峰值的相对强度Ⅰ与半高宽的乘积,其计算误差仅6.32％。

宝石翡翠的合成、热行为和热稳定性的研究

按硬玉分子组成配料,在1350～1550℃的高温下灼烧,然后淬火到室温得到具有硬玉组成的玻璃,在5.0GPa,1450℃下晶化,合成了宝石翡翠,其尺寸可达到(?)12mm×6mm。并通过差热分析及高压下的淬火分析研究了翡翠在常压下及高压下的熔点变化,利用淬火、退火及老化实验研究了人工翡翠宝石的稳定性。结果表明,人工翡翠宝石的热稳定性与天然翡翠相同。

翡翠成分、结构和矿物组成的无损分析

利用便携式能量色散型X射线荧光(portable energy-dispersive X-ray fluorescence,PXRF)、外束质子激发X射线(external beam proton induced X-ray emission,PIXE)、X射线衍射(X-ray diffraction,XRD)和激光拉曼光谱(laser Raman spectroscopy,LRS)对12块样品进行了成分、结构和矿物组成分析。结果表明,PXRF和PIXE的分析结果有较好的可比性,样品主要由较纯的硬玉组成,次要元素含量较低。1块样品含少量绿辉石,一块样品主要由绿辉石组成。硬玉的Raman特征峰位于201,372,698,985,1 037cm-1,绿辉石的特征峰位于680和1 017cm-1。利用Raman光谱测试样品的裂隙处,发现3块样品含白蜡,1块样品含环氧树脂。白蜡的Raman特征峰位于2 846和2 880cm-1,环氧树脂的特征峰位于2 924和3 065cm-1。无损分析技术在翡翠中的应用拓展了样品的研究范围,为翡翠的进一步研究、鉴定和分级提供了技术支持。

翡翠烧红实验温度探究

由于商业化的原因,翡翠烧红工艺及其内容方面的资料很难获得,作者在翡翠烧红实验研究过程中进行了多组翡翠烧红实验,初步获得了烧红翡翠的温度条件。利用差热分析手段对翡翠样品进行了分析,结合实验样品外观分析,探讨了烧红实验中温度因素与翡翠水头和颜色变化的一些联系。

与翡翠伴生钠长石的矿物学特征研究

市场上与翡翠极其相似的钠长石越来越多。通过外观特征、镜下观察、红外光谱分析、粉末X射线衍射分析等手段,研究了与缅甸翡翠相伴生的钠长石的矿物学特征,从而为珠宝鉴定中如何区分钠长石与翡翠提供了依据。外观上,钠长石常呈白等浅色调和不同色调的绿色。光学显微镜下观察,第一世代的钠长石早于翡翠形成,第二世代的钠长石与翡翠共生,除钠长石和硬玉外,还有角闪石及不透明的黑色矿物,钠长石发育有聚片双晶。粉末X射线衍射分析结果显示缅甸与翡翠相伴生的钠长石是有序的,属低温钠长石。

西双版纳翡翠市场营销策略分析

翡翠因其稀缺性而具有比较稳定的价值。西双版纳凭借靠近翡翠原产地缅甸的地理优势,形成了相应的翡翠市场。深入分析西双版纳翡翠市场,研究其营销策略及存在的问题,针对其国内和国外市场竞争环境,提出可行的营销发展对策和措施。

Transient-Spatial Pattern Mining of Eddy Current Pulsed Thermography Using Wavelet Transform

Eddy current pulsed thermography（ECPT） is an emerging Non-destructive testing and evaluation（NDT E） technique, which uses hybrid eddy current and thermography NDT E techniques that enhances the detectability from their compensation. Currently, this technique is limited by the manual selection of proper contrast frames and the issue of improving the efficiency of defect detection of complex structure samples remains a challenge. In order to select a specific frame from transient thermal image sequences to maximize the contrast of thermal variation and defect pattern from complex structure samples, an energy driven approach to compute the coefficient energy of wavelet transform is proposed which has the potential of automatically selecting both optimal transient frame and spatial scale for defect detection using ECPT. According to analysis of the variation of different frequency component and the comparison study of the detection performance of different scale and wavelets, the frame at the end of heating phase is automatically selected as an optimal transient frame for defect detection. In addition, the detection capabilities of the complex structure samples can be enhanced through proper spatial scale and wavelet selection. The proposed method has successfully been applied to low speed impact damage detection of carbon fibre reinforced polymer（CFRP） composite as well as providing the guidance to improve the detectability of ECPT technique.

Proton induced X-ray emission (PIXE) analysis of sources of porcelain body of Ru Guan and Jun Guan porcelains

34 samples of Ru Guan porcelain body and 50 samples of Jun Guan porcelain body (both kinds being in different body colors) were selected with the purpose of finding out the source of raw materials and their classification relationship so as to search for ways of non-destructive discrimination. Proton induced X-ray emission (PIXE) has been applied to these samples to determine their chemical elements. The data of seven major chemical elements collected from these samples were further studied through fuzzy cluster analysis. Results indicate that the origin of raw materials of Jun Guan porcelain body samples is comparatively more concentrated in certain places, while that of Ru Guan porcelain body samples is scattered about. The places of origin of raw materials of the majority of Ru Guan and Jun Guan porcelain body samples have something in common, but some differences still exist. It might be an important way for non-destructive discrimination among Ru Guan and Jun Guan porcelains by combining PIXE with fuzzy cluster analysis.