Due to complex scattering from the sample dark matrix, absorption in the detector window and the competing Auger effect with higher cross-section for low Z elements (Z < 14), direct quantification of low Z elements by measuring characteristic X-ray fluorescence intensities during energy dispersive X-ray fluorescence (EDXRF) analysis of geological samples is challenging. This paper reports the chemometric quantitative analysis model of low Z elements (O, Na, Mg, and Al) in geological samples obtained by training the backpropagation neural network (BPNN) using the Compton scatter data combined with the concentrations of measurable elements. The training data is derived from the measured spectra of soil and rock standard samples and their synthetic samples configured with compounds. The standardized Compton scatter data and correlated element concentrations were used as the input data of the BPNN model. The prediction results of the BPNN model show that the coefficient of determination (R2) values between true and predicted concentrations for O, Na, Mg, and Al are both >0.95. It implied that the modeling approaches significantly overcome matrix effects between the concentrations of low Z elements and Compton scatter peaks. So, the method has the potential for being widely used in the analysis of samples rich in low Z elements.

This paper reports a method for measuring the true porosity of ceramic samples based on X-ray transmission. The measurement of the true porosity of ancient Ding kiln white porcelain and two daily white porcelains was carried out by X-ray transmission method. The research results show that the average true porosity of ancient Ding kiln white porcelain, daily white porcelain A, and daily white porcelain B measured by the X-ray transmission method is 5.44%, 9.10%, and 13.97%, respectively; and the values measured by the suspension method were 5.35%, 8.43%, and 12.89%, respectively. Although the true porosity values of the ceramic samples measured by the X-ray transmission method are slightly larger than the measurement value of the suspension method, they are in good agreement with each other. In addition, compared with the suspension method, the X-ray transmission method has significant advantages such as simple operation and short measurement time.

The fitting software QMXRS (Quantitative analysis of Micro-Energy Dispersive X-ray fluorescence spectra) which is used for fitting micro-energy X-ray fluorescence spectrum focused by poly-capillary optics is developed in our Lab with Python language. The signal de-noising of the wavelet transform, background subtraction, energy calibration and characteristic peak fitting of spectrum is carried out by QMXRS. The ploy-capillary X-ray optics used here can improve the intensity of X-ray and change the distributions of X-ray fluorescence spectra. The background prediction model of QMXRS can effectively retain peak information and improve the accuracy of data processing of energy spectra. On the other hand, the constraint of the full width at half maximum(FWHM) of the Gaussian peak is added to the conventional nonlinear least-squares fitting. The Micro-Energy dispersive X-ray fluorescence spectra of the NIST 610 standard sample is used to demonstrate the performances of QMXRS. The results show that our QMXRS is better than PyMca and QXAS.

The X-ray diffraction analysis is a nondestructive phase analytical method has been widely used in archaeology, physical chemistry, geoscience and materialogy, etc.. In this study, we developed a type of X-ray diffractometer equipped with slightly-focusing ploycapillary optics and reported some new results of this instrument. By comparing the diffraction peaks of irregular surface of the RMB 5 Jiao coin in our instrument with that of X-Pert Pro MPD (PANalytical, Holland) diffractometer. The results show that our instrument can get the accurate phases but the peaks’ positions of the phases of X-Pert Pro MPD drift largely. Moreover, our instrument measured the color glaze of a piece of ancient porcelain fired in Jizhou kiln. It shows that the 3Al2O3·2SiO2 (PDF 15-0776) and Fe2O3 (PDF 25-1402) are the main crystal structures in white glaze, the black glaze is mainly composed of the Fe3O4 (PDF 28-0491) and 3Al2O3·2SiO2 and the main phase of body is 3Al2O3·2SiO2 (PDF 15-0776) and quartz (PDF 46-1045). From those results, we can understand that the white glazes are fired in a high temperature about 1250°C while the black glaze is fired in low temperature. That is helpful to understand the firing and coloring process with color glaze of ancient porcelain fired Jizhou kiln. Therefore, it can be concluded that slightly-focusing ploycapillary optics diffractometer has broader application prospects in the analysis of samples with irregular or curving surface.

In order to realize micron scale to millimeter scale phase structure analysis, as well as accurate phase structure analysis of surface uneven samples, X-ray diffractometer named Hawk-II, which can adaptively adjust the diameter of irradiated X-ray beam spot according to the diameter of internal tangential circle at the measured point, is developed by combining X-ray diffraction technology, CCD camera imaging technology and slightly-focusing ploycapillary X-ray control technology. The X-ray source system, six-dimensional linkage motion system, CCD camera, detection system and control system based on LabVIEW are the main components of the Hawk-II. Compared with the 3°–5° divergence of the conventional X-ray source, the divergence of the X-ray emitted by the slightly-focusing polycapillary X-ray optics is only about 0.15° and also the intensity within the beam spot range is dozens of times stronger. Therefore, the shift of peak position will not appear due to the pores, curvature or uneven surface of the sample, when Hawk-II is used to analyze the samples with irregular surface. The diffraction pattern of the uneven Ren Min Bi five-cent coin are collected in the Hawk-II and PANalytical X-Pert Pro MPD conventional X-ray diffractometer respectively. By comparing the analysis results, it is found that the diffraction peaks measured by the X-Pert Pro MPD are shifted seriously, with a maximum deviation angle of 0.52°. While the diffraction peaks detected by the Hawk-II are basically consistent with the data from the standard PDF card, which verifies the advantages of the analysis of irregular samples by the Hawk-II. In order to explore the difference between different beam spots used for analysis at the same point, red and green porcelain fired in Qing dynasty and GaAs-based Cu and Fe plated films are analyzed by the Hawk-II. It is found that when the samples are relatively uniform, the intensities of diffraction peaks of different beam spots are relatively close, while when the samples are not uniform, the diffraction peaks vary greatly. Especially, some microcrystalline phases can be detected only with large beam spots. In addition, to verify the adaptive functionality of the Hawk-II, a bronze from the Western Han Dynasty, with different rust spots on it, is tested. It is found that the Hawk-II can adjust the beam spot size according to the different corrosion points, making the irradiation area coincide with the area to be analysed and the phase structure detected more accurately. Therefore, the Hawk-II is a general purpose X-ray diffractometer, which has the analytical capability from micron scale to millimeter scale and the energy dispersive X-ray fluorescence analysis function. Moreover, it has the advantages of the accurate analysis of irregular samples, fast detection speed, simple operation, etc. Based on the above analysis, the Hawk-II will be widely used in different fields.

本文研究了一种微束X射线衍射仪,并对其硬件、软件和性能进行了介绍.该衍射仪采用毛细管X光透镜将X射线束会聚到μm量级,并通过由PLC和步进电机等组成的闭环运动控制系统调节三维样品台来实现对样品微区的物相分析和物相的二维扫描分析.利用自行开发的控制软件实现了微区X射线衍射分析和微区能量色散X射线荧光分析两种模式.为了验证设备的可行性,采用本微束X射线衍射仪以微区X射线衍射的方式扫描了苹果手机主板的焊锡接触点上1.0 mm×0.6 mm的区域,得到了区域内SnO2(312)的晶相分布图.此外,利用本微束X射线衍射仪分析了1片清代红绿彩瓷表面的白色瓷釉和彩料中钾长石和钙长石等主要的晶相,这些实验数据可为古代瓷器的烧制工艺提供有益的参考.因此,这种微束X射线衍射仪在材料、文物保护等研究领域具有广泛的应用前景.

Micro-X-ray diffraction (μ-XRD) plays a significant role in measuring the phase structures of small samples or micro areas of larger samples. In this article, we propose a new type of desktop micro-X-ray diffractometer named μ-Hawk focused by polycapillary optics. It consists mainly of a microfocus X-ray tube, polycapillary optics, receiving slits, a silicon drift diode (SDD) X-ray detector integrated with single/multi-channel pulse analyzer, independently rotating θ-θ goniometer, high precision XYZ sample stage, computer programs developed by LabVIEW codes, etc. The main interface of the program has micro-X-ray diffraction analysis mode and micro energy dispersive X-ray fluorescence analysis mode. In addition, the monochromatization of X-ray, the angular resolution and the accuracy of the results of μ-Hawk are discussed. In order to demonstrate the feasibility of the instrument, the phase of micro area in the middle of the first stroke on the Chinese character “Jiao” from a 5-Jiao coin (Chinese currency) is measured by the μ-Hawk, and the phase of a copper wire 140 μm in diameter is also detected by it. After that, the phase of 1.0 mm × 0.6 mm area on the welding joint of the motherboard from an iPhone is two-dimensionally scanned by μ-Hawk. The θ-θ scanning is performed at each detected point inside the two-dimensional area. Four motors drive the X and Y axis of the sample stage as well as the θ1 and θ2 axis of the goniometer to accomplish the above functions. The results show that the micro energy dispersive X-ray fluorescence analysis mode of μ-Hawk can provide elementary reference information for the analysis of phase structure. Compared with conventional X-ray diffractometer, the μ-Hawk can detect the same diffraction peaks on the coin with lower background. Furthermore, the accurate diffraction peaks can be measured with a lower power and shorter time. The measured results can better reflect the true phase structure of the micro area. Six diffraction peaks and their phases can be clearly identified from the diffraction pattern of the copper wire. For the welding joint, the phase mapping of SnO2 (3 1 2) is acquired through data processing. Therefore, the μ-Hawk can adapt to the micro-X-ray diffraction analysis of small samples or micro areas of samples as well as the two-dimensional scanning analysis of phase mapping. The μ-Hawk exhibits the unique advantages of accomplishing accurate micro-X-ray diffraction analysis, convenient software, low working power, time saving, and small in size. It indicates a wide application prospect in the fields of materials, geosciences and heritage protection.

The portable micro-X-ray fluorescence analysis with polycapillary optics has advantages of being non-destructive, and it has been widely used in the analysis of cultural relics. However, due to the irregular or curving surface of archaeological objects and the shortcoming of polycapillary optics in focusing X-rays, the distances between the irradiation spot of samples and exit of polycapillary optics are variables. As a result, the sizes of focused X-ray spot cant keep constant, which reduces the accuracy of measurement and the resolution of elemental mappings of scanning area. In this paper, we propose a new type of portable micro -X-ray fluorescence spectrometer that consists of a new closed loop feedback system and SDD X-ray detector, 30W lower power X-ray tube, polycapillary optics, CCD and so on. In particularly, the closed loop feedback system is composed of Laser Displacement Sensor (LDS) stepper motor, sample stage and computer programs developed by LabVIEW languages. During measuring, the LDS accurately controls the distances between the irradiation spot of samples and exit of polycapillary optics. Based on this closed loop feedback system, our portable micro X-ray fluorescence spectrometer can keep the sizes of focused X-ray spot constant. On the other hand, we provide different alternative sizes of focused X-ray spot by controlling the distances between the exit of polycapillary optics and measured spot of samples in our spectrometer. In order to test the feasibility of this instrument, the concentration of elements and elemental mappings of K, Ca, Zn, Fe and other elements in the irregular colored glaze of a piece of ancient porcelain have been measured by our portable micro X-ray fluorescence spectrometer under enabling and disabling LDS conditions. From the results, it can be concluded that the concentration of elements is very close to the real values and the resolution of elemental mappings is better when LDS is enabled. This indicates that the closed loop feedback system based on LDS can accurately reduce the measurement errors caused by the irregular or curving surface of archaeological objects. Therefore, this portable micro X-ray fluorescence spectrometer developed by our laboratory has potential application prospects in nondestructive analysis of cultural relics.

研制了便携式微束X射线荧光谱仪,并对其硬件、软件和性能等特征进行了分析.该谱仪应用激光位移传感器实时检测样品测量点到透镜出端之间的距离并自动调节该距离的方法,来解决考古样品表面不平整或弧度而造成的照射样品X射线束斑变化的问题,从而保证X射线照射光斑大小不变.为验证谱仪的可靠性,采用该谱仪测量了表面高度差接近5 mm的古陶瓷样品微区的釉彩层元素的分布.分析结果表明,激光位移传感器能有效减少由于样品表面不平整或弧度带来的测量误差.此外,使用本谱仪分析了5角硬币表面4 mm×4 mm的区域,经过数据处理后得到Cu、Sn等元素的分布及其合金相的分布,表明该谱仪不仅可进行微区能量色散X射线荧光分析(μ-EDXRF),同时还可进行微区能量色散X射线衍射分析(μ-EDXRD).

针对不同样品的分析需求,本文设计了几种不同类型的微束X射线荧光谱仪.用高精度激光位移传感器实时校正样品表面被测量点与毛细管透镜出端之间的距离,以减少形状不规则的古陶瓷样品测量时带来的误差;利用毛细管X光透镜传输能量高于25 keV的X射线效率低的特点,将其应用于高铅釉瓷器彩料的无损分析中;采用大功率X射线源,扫描分析了大米中K、Ca等元素分布;以人民币5角硬币为例,研究了能量色散的微束X射线衍射方法.研究结果表明,本文研发的微束X射线荧光谱仪在生物样品和文物样品的分析研究中有广泛的应用前景.

In order to find out the relationship between copper-red glaze of official Jun porcelain and the chemical elements in them, the chemical elements of six color glazes of official Jun porcelain are tested. Box plot analysis and Factor analysis are used to analyze the data to explore the relationship between the glaze color and the number of chemical elements in glaze. The results show the six porcelain glazes can be divided into three categories: 1) begonia-red and chicken-blood-red; 2) purple tinged with red, blue and violet; 3) grape purple and eggplant purple.

大米是人类从外界获得营养的主要方式之一,大米中的微量元素对人体的健康有重要的意义.为人体合理补充微量元素提供参考意见.本文利用X射线荧光分析方法并结合干灰化样品前处理方法研究了岳阳、五常、新民、哈尔滨、万昌等5种不同品牌大米中K、Ca、Cr、Mn、Fe、Co、Ni、Cu、Zn、As、Se、Sr等微量元素的含量;同时,用毛细管X光透镜聚焦的微束X射线荧光扫描了单粒大米中多元素的分布.结果表明,5种品牌大米中所含微量元素种类基本相同,五常大米中对人体有益的元素Ca、Fe、Ni、Zn等含量较高;此外,P、Cl、K、Ca等元素主要富集在大米的胚芽处.大米中微量的金属元素Fe、Cu、Zn等元素分布均匀.

Energy dispersive X-ray scattering (EDXRS) technique is an effective method for identification of sorts of liquids.In this experiment,the polycapillary X-ray half optics is used to replace the slits of the EDXRS to identify the sorts of the liquid samples.The experimental results show that alignment system consisting of the two polycapillary X-ray half optics can improve the efficiency of X-ray source and the resolution of the scattering spectrum.The EDXRS with polycapillary X-ray half optics is an appropriate method to identify the sorts and concentrations of liquids,and has a widely applications for the identification of sorts of liquids.

20 samples and 44 samples of terracotta warriors and horses from the 1st and 3rd pits of Qin Shihuang’s Mausoleum, 20 samples of clay near Qin’s Mausoleum, and 2 samples of Yaozhou porcelain bodies are obtained to determine the contents of 32 elements in each of them by neutron activation analysis (NAA). The NAA data are further analyzed using fuzzy cluster analysis to obtain the fuzzy cluster trend diagram. The analysis shows that the origins of the raw material of the terracotta warriors and horses from 1st and 3rd pits are not exactly the same but are closely related to the loam soil layer near Qin’s Mausoleum while distant from the loess layers in the same area and remotely related to the Yaozhou porcelain bodies. It can be concluded that the raw material of the terracotta warriors and horses was taken from certain loam layer near Qin’s Mausoleum and the kiln sites might be located nearby.

In this paper, the px+ipy topological superconductor with vortex square superlattice is studied. We calculated the edge spectrum in the presence of vortex superlattice, and found that there exist mid-gap vortex fermion bands induced by the vortex superlattice with nontrivial topological properties, which relate to gapless edge mode and non-zero winding number. Moreover, we proposed a topological anisotropic tight-binding Majorana lattice model to describe the mid-gap states.

In this paper we study an s-wave topological SC with a square vortex-lattice. We proposed a topological Majorana lattice model to describe this topological state. We found that the Majorana lattice model is really a "topological SC" on the parent topological SC. Such correspondence between the Majorana lattice model and the topological SC with vortex-lattice is another holographic feature of the topological state. In addition, the numerical calculations confirm our theoretical prediction.

This paper puts forward an ancient porcelain system that can be identified and analyzed online. It can put discriminant analysis of ancient porcelain technology identification use to network platform. In addition, the system can provide efficient ancient porcelain identification service and collect more ancient porcelain samples data. The system exercises JSP, JavaBean and SQL Server 2000 technologies to establish an ancient porcelain database management system, and to achieve data exchange between JSP pages and database, and uses Java program to invoke Matlab program to achieve the identification analysis function. Test analysis results show that the system can be used to identify Liu Jiamen celadon porcelain, Ruguan porcelain and Zhang Gongxiang celadon porcelain.

In this paper, we use molecular dynamics simulation to analyze the diffusion and dissociation barriers of homogeneous (Cu-2) and heterogeneous dimer (Ag-2, Pd-2) on the surface of Cu(100), (111) surface. We explore the diffusion and dissociation process and characteristics of those dimers on Cu surface and compare their diffusion and dissociation barriers of dimer, the binding energies of the dimer and substrate, substrate surface textures, temperatures, etc. The semiempirical EAM potential is used in the simulation.

In order to find out the kiln of some articles unearthed at Fancui tomb of Northern Dynasty, we use the article samples to track to a kiln site near Cao village, Linzhang town, Hebei province. By compare and contrast of Cao village kiln samples with Northern Dynasty tomb articles, we conclude that Cao village kiln are of Northern Dynasty. We measure the physical properties and the chemical composition of the samples using energy dispersive X-ray fluorescence (EDXRF), and identify the samples are of lead glaze pottery, Fuzzy cluster analysis of the samples shows that Cao village kiln body samples raw materials come from 3~4 batches, while the glaze samples raw material come from 3 batches. It also shows that the body raw materials and the glaze raw materials of the sample supporting pins are the same as those of Cao Village kiln.