X-射线荧光光谱法同时测定润滑油中多种元素

润滑油中金属元素测定,目前在我国仍以化学法作为标准方法。用XRF测定石油产品中某些元素在国外已有报道,个别元素的测定已形成国际标准方法。本文作者之一曾对润滑油中Ca、Ba、Cu、Fe、Zn、P、S、CI,等元素分别建立了X-射线荧光光谱的分析方法,并用于润滑油分析中,效果良好。但随着高档润滑油的研制和生产,大量使用复合添加剂,使润滑油中金属元素种类增多,一个油样中往往含有多种待测元素,原有的分析方法已不适应。为此,我们研究以人工合成含多种元素的润滑油标准样品。

X-ray Spectroscopically Probing Mo_(2)C@MoSe_(2)Heterojunction Electrodes

Due to their high electrical conductivity and layered structure,two dimensional MXene materials are re⁃garded as promising candidates for energy storage applications.However,the relatively low stability and specific ca⁃pacity of MXene materials limit their further utilization.In this study,these issues are addressed using a heterostruc⁃ture strategy via a one-step selenization method to form Mo_(2)C@MoSe_(2).Synchrotron radiation X-ray spectroscopic and high-resolution transmission electron microscopy(HRTEM)characterizations revealed the heterostructure consisting of in-situ grown MoSe_(2)on Mo_(2)C MXene.Electrochemical tests proved the heterojunction electrode’s superior rate perfor⁃mance of 289.06 mAh·g^(-1)at a high current density of 5 A·g^(-1)and long cycling stability of 550 mAh·g^(-1)after 900 cycles at 1 A·g^(-1).This work highlights the useful X-ray spectroscopic analysis to directly elucidate the heterojunction structure,providing an effective reference method for probing heterostructures.

弱Gorenstein X-投(内)射模

引入弱Gorenstein X-投(内)射模,讨论其基本同调性质,证明在任意环R上,若lD(R) ≤ 1,则Gorenstein X-投(内)射模类、弱Gorenstein X-投(内)射模类、Gorenstein投(内)射模类和弱Gorenstein投(内)射模类是同一个类。

A Novel High Temperature Apparatus for in situ Synchrotron X-ray Diffraction Studies of Molten Salt

This study demonstrates the design and application of a novel high temperature rotatory apparatus for insitu synchrotron X-ray diffraction studies of molten salts,facilitating investigation into the interaction between various structural materials and molten salts.The apparatus enables accurate detection of every phase change during hightemperature experiments,including strong reaction processes like corrosion.Molten salts,such as chlorides or fluo⁃rides,together with the structure materials,are inserted into either quartz or boron nitride capillaries,where X-ray diffraction pattern can be continuously collected,as the samples are heated to high temperature.The replacement re⁃action,when molten ZnCl2 are etching Ti3AlC2,can be clearly observed through changes in diffraction peak intensity as well as expansion in c-axis lattice parameter of the hexagonal matrix,due to the larger atomic number and ionic ra⁃dius of Zn2+.Furthermore,we investigated the high-temperature corrosion process when GH3535 alloy is in FLiNaK molten salt,and can help to optimize its stability for potential applications in molten salt reactor.Additionally,this high temperature apparatus is fully compatible with the combined usage of X-ray diffraction and Raman technique,providing both bulk and surface structural information.This high temperature apparatus has been open to users and is extensively used at BL14B1 beamline of the Shanghai Synchrotron Radiation Facility.

C_(60)/花生酸混合LB膜 Ⅰ.LB膜的X射线衍射和分子排列模型

制备了纯C60和C60／AA的混合LB膜。用X－射线衍射详细研究了它们的周期结构，表明C60分子在C60／AA混合LB膜中不是顶在花生酸疏水端头，而是包埋在花生酸分子之间。由此提出了一个新的分子排列模型。

Evaluation on residual stresses of silicon-doped CVD diamond films using X-ray diffraction and Raman spectroscopy

The effect of silicon doping on the residual stress of CVD diamond films is examined using both X-ray diffraction (XRD) analysis and Raman spectroscopy measurements. The examined Si-doped diamond films are deposited on WC-Co substrates in a home-made bias-enhanced HFCVD apparatus. Ethyl silicate (Si(OC2H5)4) is dissolved in acetone to obtain various Si/C mole ratio ranging from 0.1% to 1.4% in the reaction gas. Characterizations with SEM and XRD indicate increasing silicon concentration may result in grain size decreasing and diamond [110] texture becoming dominant. The residual stress values of as-deposited Si-doped diamond films are evaluated by both sin2ψ method, which measures the (220) diamond Bragg diffraction peaks using XRD, with ψ-values ranging from 0° to 45°, and Raman spectroscopy, which detects the diamond Raman peak shift from the natural diamond line at 1332 cm-1. The residual stress evolution on the silicon doping level estimated from the above two methods presents rather good agreements, exhibiting that all deposited Si-doped diamond films present compressive stress and the sample with Si/C mole ratio of 0.1% possesses the largest residual stress of ~1.75 GPa (Raman) or ~2.3 GPa (XRD). As the silicon doping level is up further, the residual stress reduces to a relative stable value around 1.3 GPa.

Determination of Structure and Polarity of Si C Single Crystal by X-Ray Diffraction Technique

Structure and polarity of the Si C single crystal have been analyzed with the four- circle X- ray diffraction method by a double- crystal diffractom eter.The hexagonal{ 10 15 } pole figure shows that this Si C sam ple has a6 H modification.The difference between the integrated intensities m easured byω scan in the triple- axis diffraction set- up finds some convincing evidence that the surface is either a Si- terminated face or C- terminated face.The experi- mental ratios of| F( 0 0 0 L) | 2 / | F( 0 0 0 L) | 2 are in good agreem entwith the calculated ones after the dispersion cor- rections to the atomic scattering factors( L=6 ,12 and18,respectively) .Thus,this m easurem ent technique is con- venient for the application of the materials with remarkable surface polarity.

NOVEL CELESTIAL NAVIGATION FOR SATELLITE USING X-RAY PULSARS

The X-ray pulsar-based navigation is a novel technology for the satellite autonomous navigation. The position and the velocity of the satellite are deterimined by using the pulse phases detected at the satellite and predicted by the pulse timing models. With the detected pulse phase, the satellite position with respect to the Earth center can be calculated along the line-of-sight to the pulsar. Using three pulsars, the satellite position in the in- ertial frame can be resolved. The extended Kalman filter （EKF） algorithm is designed to incorporate the range measurements with the satellite dynamics. Simulation verification shows that the proposed algorithm can accu- rately determine the satellite orbit, with the position error less than 100 m. Furthermore, the factors influencing the navigation performance are also discussed.

X-ray Comparative Analysis of Rhubarb in Different Production Areas of Qinghai

[Objective] The aim of this study was to provide a basis for distinguishing quality of rhubarb in different production areas. [Method ] X-ray diffraction patterns of rhubarbs in different production areas of Qinghai were obtained by X-ray diffraction analysis, and then its similarity analysis was also investigated. [ Result] The content of chemical components in rhubarbs from different production areas had differences, but its diffraction patterns and diffraction peaks had certain fingerprint characteristics. [ Conclusion] X-ray diffraction method is a fast and effective method for identifying rhubarb and other Chinese herbal medicines in different production areas.

Analysis of PTCDA/ITO Surface and Interface Using X-ray Photoelectron Spectroscopy and Atomic Force Microscopy

The electronic states of the surface and interface of 3,4, 9, 10-perylenetetracarboxylic dianhydride （PTCDA）/indium-tin-oxide （ITO） thin film are investigated using X-ray photoelectron spectroscopy （XPS）. A- tomic force microscopy （AFM） is also applied to investigate the pattern of PTCDA/ITO film. XPS results show that there are two main peaks,which are associated with C atoms in the perylene rings and acid anhydride groups, located at 284.6 and 288.7eV, respectively,in the Cls spectrum of the original surface. It can be deduced from the emergence of a small peak at 290.4eV in the Cls spectrum that some C atoms are oxidized by O atoms from ITO. The binding energies of O atoms in C-O bonds and C--O---C bonds are 531.5 and 533.4eV respectively. At the interface,the peak at the high binding energy in the Cls spectrum disappears,and the peak value shifts about 0.2eV to lower binding energy, There is a significant 1.5eV chemical shift to lower binding energy in the Ols spectrum. These observations indicate that perylene rings inside PTCDA molecules are combined with In vacancies in the ITO at the interface. The AFM results show that PTCDA molecules formed an island-like structure a height of about 14nm. The sizes of the crystal grains are about 100--300nm. The island-like pattern comes from the delocalized π bonds of adjacent molecules in PTCDA and the combination of vacancies in ITO with perylene rings at the PTCDA/ITO interface.

A Straightforward Method of Calculating Finely the Soft X-Ray Spectra of Hydrogenlike Highly Ionized-States

A new method of calculating finely the soft X ray spectra of hydrogenlike highly ionized states is presented. It is based on the relation of the ionicity and the ionization energies of hydrogenlike atoms and the new model of potential function of hydrogenlike atoms. The relativistic revision and the spin orbit couping of excitation energy levels are taken into account. The calculated results are in good agreement with the experiments.

Projection registration of X-ray image and CT image

A methodology for alignment of an X-ray image and a CT image, based on the Chamfer 3-4 distance transform and simulated annealing optimization algorithm is presented. Firstly, an initial transformation matrix is constructed. For the convenience of computing, geometric models of the X-ray device to reconstruct the calibration matrix are used. Then, by defining the distance between the 3-D protective and the 2-D object image, we optimize this distance matching problem, using the simulated annealing algorithm. This method is also integrated into medical intra-operation, dealing with the data set acquired from 3-D image workstation and active navigation.

X-ray image distortion correction based on SVR

X-ray image has been widely used in many fields such as medical diagnosis,industrial inspection,and so on.Unfortunately,due to the physical characteristics of X-ray and imaging system,distortion of the projected image will happen,which restrict the application of X-ray image,especially in high accuracy fields.Distortion correction can be performed using algorithms that can be classified as global or local according to the method used,both having specific advantages and disadvantages.In this paper,a new global method based on support vector regression（SVR）machine for distortion correction is proposed.In order to test the presented method,a calibration phantom is specially designed for this purpose.A comparison of the proposed method with the traditional global distortion correction techniques is performed.The experimental results show that the proposed correction method performs better than the traditional global one.

Analysis of Wettability and X-ray Photoelectron Spectroscopy of Wheat Straw/SPI

[Objective] The aim was to improve the adhesive bonding property of wheat straw surface to prepare wheat straw particleboard of soy protein isolate （SPI） adhesive through chemical and enzyme treatments. [Method] Evaluation and analysis were made on wettability of wheat straws in the control group and treated groups （chemical and enzyme treatments） by means of measurement of contact angle and calculation of spreading-penetration parameters （K）. In addition, we made analysis on surface elements through X-ray photoelectron spectroscopy （XPS）. [Result] The re- sults showed that K value of straw treated with sodium hydroxide, hydrogen peroxide and lipase increased by 58.0%, 48.7% and 83.2% compared to that of control group, respectively. The XPS analysis indicated that rapid decrease of silicon content and destruction of wax layer greatly contributed to wettability improvement of wheat straw surface. [Conclusion] The chemical and lipase treatments of wheat straw provided technical support for manufacture of wheat straw particle boand.

In situ analysis of multi-twin morphology and growth using synchrotron polychromatic X-ray microdiffraction

Synchrotron polychromatic X-ray microdiffraction（micro-XRD） was applied to study in situ deformation twinning of commercially AZ31（Mg-3Al-1Zn） strip subjected to uniaxial tension.The morphology and growth of twins were analyzed in situ under the load level from 64 to 73 MPa.The X-ray microdiffraction data,collected on beamline 12.3.2 at the Advanced Light Source,were then used to map an area of 396μm x 200μm within the region of interest.The experimental set-up and X-ray diffraction microscopy with a depth resolution allow the position and orientation of each illuminated grain to be determined at the submicron size.A list of parent grains sorted by crystallographic orientation were selected to examine their twinning behavior.The results depict twin variant selection,local misorientation fluctuation and mosaic spread for multi-twins within the same parent grain.As load increases,the amplitude of misorientation fluctuation along twin trace keeps increasing.This is attributable to the accumulation of geometrically necessary dislocations.

X-ray and DFT Study of Glaucocalyxin A Compound with Cytotoxic Activity

The title compound glaucocalyxin A （1） （Ta,14β-dihydroxy-ent-kaur-16-en-3,15-dione） iso- lated from the leaves of isodon excisoides was characterized by IR, 1H NMR, 13C NMR, 1H-1H COSY, HMQC, HMBC, and EIMS, and its crystal structure was determined by singlecrystal X-ray diffraction. The X-ray crystal structure revealed that the molecular backbone of the chosen crystal is a tetracyclic system, including three six-membered rings and a five- membered ring, and the three six-membered rings are in a chair-like conformation. The five-membered ring adopts a twisted envelope-like conformation, and its geometrical param- eters were compared with theoretical calculations at the B3LYP and HF level of theory. The molecules form extensive networks through the intra- and intermolecular hydrogen bonds. The experimental NMR data were interpreted with the aid of magnetic shielding constant calculations, by means of the GIAO （gauge-Including atomic orbitals） method. Calculated and experimental results were compared with a satisfactory level of agreement. Molecular electrostatic potential map was used in an attempt to identify key features of the diterpenoid glaucocalyxin A that is necessary for its activity. Calculations of molecular electrostatic po- tential and stabilization energies suggest that the protonation of glaucocalyxin A will be able to occur on carbonyl oxygen atoms.

Defect Cluster-Induced X-Ray Diffuse Scattering in GaN Films Grown by MOCVD

High-resolution X-ray diffraction has been employed to investigate the diffuse scattering in a （0001） oriented GaN epitaxial film grown on sapphire substrate. The analysis reveals that defect clusters are present in GaN films and their concentration increases as the density of threading dislocations increases. Meanwhile, the mean radius of these defect clus- ters shows a reverse tendency. This result is explained by the effect of clusters preferentially forming around dislocations, which act as effective sinks for the segregation of point defects. The electric mobility is found to decrease as the cluster concentration increases.

Geochemical analysis of marine sediments using fused glass disc by X-ray fluorescence spectrometry

A method was developed for content determination of Na, Mg, A1, Si, P,S, C1, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Nb, Zr, Y, Sr, Rb, Ba, La and Ce etc. covering 26 major, minor, and trace elements in marine sediment samples using fused glass disc by X-ray Fluorescence spectrometry. Calibration was made using marine sediment certified reference materials and the synthetic standard samples prepared by mixing several marine sediments with stream sediment and carbonate standard samples in different proportions. The matrix effect was corrected using theoretical alpha coefficients, experience coefficients and the scattered radiation as the internal standard （for the trace elements）. The accuracy of the method was evaluated by analysis of certified reference materials GBW07314, GBW07334 and GSMS6. The results are in good agreement with the certified values of the standards with RSD less than 2.60%, except for Y, Cr, Ga, Ce, La, Nb, Rb, and V with RSD less than 9.0% （n=12）.

SnO_2-based solid solutions for CH_4 deep oxidation: Quantifying the lattice capacity of SnO_2 using an X-ray diffraction extrapolation method

A series of SnO2‐based catalysts modified by Mn, Zr, Ti and Pb oxides with a Sn/M （M=Mn, Zr, Ti and Pb） molar ratio of 9/1 were prepared by a co‐precipitation method and used for CH4 and CO oxidation. The Mn3＋, Zr4＋, Ti4＋and Pb4＋cations are incorporated into the lattice of tetragonal rutile SnO2 to form a solid solution structure. As a consequence, the surface area and thermal stability of the catalysts are improved. Moreover, the oxygen species of the modified catalysts become easier to be reduced. Therefore, the oxidation activity over the catalysts was improved, except for the one modified by Pb oxide. Manganese oxide demonstrates the best promotional effects for SnO2. Using an X‐ray diffraction extrapolation method, the lattice capacity of SnO2 for Mn2O3 was 0.135 g Mn2O3/g SnO2, which indicates that to form stable solid solution, only 21%Sn4＋cations in the lattice can be maximally replaced by Mn3＋. If the amount of Mn3＋cations is over the capacity, Mn2O3 will be formed, which is not favorable for the activity of the catalysts. The Sn rich samples with only Sn‐Mn solid solution phase show higher activity than the ones with excess Mn2O3 species.

Soil Macropore Structure Characterized by X-Ray Computed Tomography

Undisturbed soil core with many macropores and disturbed soil core with onlyone macropore (diameter is 10 mm) were probed by X-ray computed tomography (CT). The size, number,shape and continuity of macropores in the transverse and vertical sectionsof soil were characterizedusing CT scanning images. The probability densities of macropores in the transverse section of soilcore exhibited a logarithmic P distribution. Results indicated that CT scanning was a promisingnondestructive method for characterizing macropores in soils.