Understanding Pseudocapacitance Mechanisms by Synchrotron X-ray Analytical Techniques

Pseudocapacitive materials that store charges via reversible surface or near-surface faradaic reactions are capable of overcoming the capacity limitations of electrical double-layer capacitors.Revealing the structure–activity relationship between the microstructural features of pseudocapacitive materials and their electrochemical performance on the atomic scale is the key to build high-performance capacitor-type devices containing ideal pseudocapacitance effect.Currently,the high brightness(flux),and spectral and coherent nature of synchrotron X-ray analytical techniques make it a powerful tool for probing the structure–property relationship of pseudocapacitive materials.Herein,we report a comprehensive and systematic review of four typical characterization techniques(synchrotron X-ray diffraction,pair distribution function[PDF]analysis,soft X-ray absorption spectroscopy,and hard X-ray absorption spectroscopy)for the study of pseudocapacitance mechanisms.In addition,we offered significant insights for understanding and identifying pseudocapacitance mechanisms(surface redox pseudocapacitance,intercalation pseudocapacitance,and the extrinsic pseudocapacitance phenomenon in battery materials)by combining in situ hard XAS and electrochemical analyses.Finally,a perspective for further depth of understanding into the pseudocapacitance mechanism using synchrotron X-ray analytical techniques is proposed.

Thermal Diffusion of Si Atoms at the Interface of Mo/Si Bilayers Studied with a Soft X-ray Emission Microscope

Thermal diffusion of Si atoms at the interface in Mo/Si multilayers was observed with an imaging type soft X ray emission microscope developed by us. It was possible to observe the diffusion with 0.2nm depth resolution in the direction normal to the interface by comparing the emission intensity for exactly the same position. The diffusion coefficient of Si atoms in Mo at 600℃ was roughly estimated to be 6.0×10 17 cm 2/s.

Atmospheric transmission algorithm for pulsed X-rays from high-altitude nuclear detonations based on scattering correction

In high-altitude nuclear detonations,the proportion of pulsed X-ray energy can exceed 70%,making it a specific monitoring signal for such events.These pulsed X-rays can be captured using a satellite-borne X-ray detector following atmospheric transmission.To quantitatively analyze the effects of different satellite detection altitudes,burst heights,and transmission angles on the physical processes of X-ray transport and energy fluence,we developed an atmospheric transmission algorithm for pulsed X-rays from high-altitude nuclear detonations based on scattering correction.The proposed method is an improvement over the traditional analytical method that only computes direct-transmission X-rays.The traditional analytical method exhibits a maximum relative error of 67.79% compared with the Monte Carlo method.Our improved method reduces this error to within 10% under the same conditions,even reaching 1% in certain scenarios.Moreover,its computation time is 48,000 times faster than that of the Monte Carlo method.These results have important theoretical significance and engineering application value for designing satellite-borne nuclear detonation pulsed X-ray detectors,inverting nuclear detonation source terms,and assessing ionospheric effects.

X-ray phase-sensitive microscope imaging with a grating interferometer:Theory and simulation

A general theoretical framework is presented to explain the formation of the phase signal in an x-ray microscope integrated with a grating interferometer,which simultaneously enables the high spatial resolution imaging and the improved image contrast.By using this theory,several key parameters of phase contrast imaging can be predicted,for instance,the fringe visibility and period,and the conversion condition from the differential phase imaging(DPI)to the phase difference imaging(PDI).Additionally,numerical simulations are performed with certain x-ray optical components and imaging geometry.Comparison with the available experimental measurement[Appl.Phys.Lett.113063105(2018)]demonstrates the accuracy of this developed quantitative analysis method of x-ray phase-sensitive microscope imaging.

The Method of Testing for Asbestos in Electronic and Electric Products through Polarizing Microscope and X-Ray Diffraction

Asbestos is widely applied in such sectors as manufacturing automobiles, tractors, chemical industrial equipment, and electric equipment. Asbestos fiber is harmful to human health. Therefore, the technology of testing for asbestos in products is especially important. At present, in our country’s national specifications, there is no determination method or specification that is applicable to the asbestos in electronic and electric products. In this article, the components of asbestos in electronic and electric products are identified using the method of combining polarizing microscope with X-ray diffractometer. This method is simple, fast, highly reliable, and suitable to be widely adopted.

Analytical solution of crystal diffraction intensity

Plasma density and temperature can be diagnosed by x-ray line emission measurement with crystal,and bent crystals such as von Hamos and Hall structures are proposed to improve the diffraction brightness.In this study,a straightforward solution for the focusing schemes of flat and bent crystals is provided.Simulations with XOP code are performed to validate the analytical model,and good agreements are achieved.The von Hamos or multi-cone crystal can lead to several hundred times intensity enhancements for a 200μm plasma source.This model benefits the applications of the focusing bent crystals.

Energy-dispersive X-ray Spectroscopy for the Quantitative Analysis of Pyrite Thin Specimens

To explore ways to improve the accuracy of quantitative analysis of samples in the micrometer to nanometer range of magnitudes,we adopted analytical transmission electron microscopy(AEM/EDS)for qualitative and quantitative analysis of pyrite materials.Additionally,the k factor of pyrite is calculated experimentally.To develop an appropriate non-standard quantitative analysis model for pyrite materials,the experimentally calculated k factor is compared with that estimated from the non-standard quantitative analytical model of the instrument software.The experimental findings demonstrate that the EDS attached to a TEM can be employed for precise quantitative analysis of micro-and nanoscale regions of pyrite materials.Furthermore,it serves as a reference for improving the results of the EDS quantitative analysis of other sulfides.

Investigation of bubbles escape behavior from low basicity mold flux for high-Mn high-Al steels using 3D X-ray microscope

During the continuous casting process of high-Mn high-Al steels,various types of gases such as Ar need to escape through the top of the mold.In which,the behavior of bubbles traversing the liquid slag serves as a restrictive link,closely associated with viscosity and the thickness of liquid slag.In contrast to two-dimensional surface observation,three-dimensional(3D)analysis method can offer a more intuitive,accurate,and comprehensive information.Therefore,this study employs a 3D X-ray microscope(3D-XRM)to obtained spatial distribution and 3D morphological characteristics of residual bubbles in mold flux under different basicity of liquid slag,different temperatures,and different holding times.The results indicate that as basicity of slag increases from 0.52 to 1.03,temperature increases from 1423 to 1573 K,the viscosity of slag decreases,the floating rate of bubbles increases.In addition,when holding time increases from 10 to 30 s,the bubbles floating distance increases,and the volume fraction and average equivalent sphere diameter of the bubbles solidified in the mold flux gradually decreases.In one word,increasing the basicity,temperature,and holding time leading to an increase in the removal rate of bubbles especially for the large.These findings of bubbles escape behavior provide valuable insights into optimizing low basicity mold flux for high-Mn high-Al steels.

载玻片打号机评价指标体系的建立研究

目的研究并建立一套客观完善的评价指标体系,以便从安全性、设备技术性能、适用性、易用性及可靠性多个方面对载玻片打号机进行客观全面的临床评估,明确进口和国产设备之间的差异。方法通过文献查询、产品资料分析、厂家交流、专家咨询等方法拟定初步载玻片打号机评价指标体系,并制成在线问卷,应用德尔菲法和层次分析法确定指标及权重,形成载玻片打号机指标体系。结果本文通过三轮专家咨询,构建了一套载玻片打号机评价指标体系,包含5项一级指标、25项二级指标。结论本研究所建立的载玻片打号机评价指标体系,可以相对定量的进行客观的设备评价,明确进口和国产设备之间的差异,帮助国产厂商准确定位设备的优势和不足之处,并为医疗机构的采购提供技术手段和理论基础。

The Completeness of Accreting Neutron Star Binary Candidates from the Chinese Space Station Telescope

A neutron star(NS)has many extreme physical conditions,and one may obtain some important information about an NS via accreting neutron star binary(ANSB)systems.The upcoming Chinese Space Station Telescope(CSST)provides an opportunity to search for a large sample of ANSB candidates.Our goal is to check the completeness of the potential ANSB samples from CSST data.In this paper,we generate some ANSBs and normal binaries under the CSST photometric system by binary evolution and binary population synthesis method and use a machine learning method to train a classification model.Although the Precision(94.56%)of our machine learning model is as high as before study,the Recall is only about 63.29%.The Precision/Recall is mainly determined by the mass transfer rate between the NSs and their companions.In addition,we also find that the completeness of ANSB samples from CSST photometric data by the machine learning method also depends on the companion mass and the age of the system.ANSB candidates with a low initial mass companion star(0.1 M_(⊙)to 1 M_(⊙))have a relatively high Precision(94.94%)and high Recall(86.32%),whereas ANSB candidates with a higher initial mass companion star(1.1 M_(⊙)to 3 M_(⊙))have similar Precision(93.88%)and quite low Recall(42.67%).Our results indicate that although the machine learning method may obtain a relatively pure sample of ANSBs,a completeness correction is necessary for one to obtain a complete sample.

雪菊质量标准及抗氧化活性研究

目的:建立雪菊的质量检验方法,评价不同产地雪菊的抗氧化活性。方法:对12批雪菊进行性状及显微鉴别;参照2020年版《中华人民共和国药典》方法测定水分、总灰分、浸出物含量;紫外-可见分光光度法(UV-Vis)测定雪菊总黄酮含量;测定12批雪菊的1,1-二苯基-2-三硝基苯肼(DPPH)自由基清除率及对小鼠血清超氧化物歧化酶(SOD)活力和丙二醛(MDA)浓度的影响;采用层次分析-变异系数法结合优劣解距离法评价不同产地雪菊抗氧化活性。结果:12批雪菊性状稳定,水分、总灰分为(6.92±0.02)%~(9.71±0.12)%、(5.90±0.03)%~(7.46±0.21)%,水溶性和醇溶性浸出物分别为(38.63±0.30)%~(45.78±0.07)%、(40.77±0.14)%~(46.55±0.24)%,雪菊总黄酮含量为(168.44±1.27)~(289.42±0.25)mg/g;12批雪菊抗氧化活性排序为S1(新疆克里阳)>S8(云南丽江)>S6(青海都兰)>S2(新疆库尔勒)>S7(云南昆明)>S12(西藏拉萨)>S5(青海西宁)>S9(云南丽江)>S3(新疆克里阳)>S4(青海西宁)>S11(西藏林芝)>S10(西藏林芝)。结论:初步拟定雪菊中水分、总灰分不超过12%、8%,水溶性浸出物、醇溶性浸出物均不少于30%,雪菊总黄酮含量不低于160 mg/g。S1(新疆克里阳)、S8(云南丽江)和S6(青海都兰)的雪菊抗氧化活性较好。

X-Ray Analysis by Williamson-Hall and Size-Strain Plot Methods of ZnO Nanoparticles with Fuel Variation

In this paper, a simple and facile surfactant assisted combustion synthesis is reported for the ZnO nanoparticles. The synthesis of ZnO-NPs has been done with the assistance of non-ionic surfactant TWEEN 80. The effect of fuel variations and comparative study of fuel urea and glycine have been studied by using characterization techniques like X-ray diffraction (XRD), transmission electron microscope (TEM) and particle size analyzer. From XRD, it indicates the presence of hexagonal wurtzite structure for ZnO-NPs. Using X-ray broadening, crystallite sizes and lattice strain on the peak broadening of ZnO-NPs were studied by using Williamson-Hall (W-H) analysis and size-strain plot. Strain, stress and energy density parameters were calculated for the XRD peaks of all the samples using (UDM), uniform stress deformation model (USDM), uniform deformation energy density model (UDEDM) and by the size-strain plot method (SSP). The results of mean particle size showed an inter correlation with W-H analysis, SSP, particle analyzer and TEM results.

钢渣粉/聚酯纤维沥青混合料水稳定性研究

为了实现钢渣粉在沥青路面中的可持续利用,同时结合河南省冬季冰雪天气下路面的除冰情况,研究了掺有聚酯纤维与钢渣粉沥青混合料的水稳定性。制备4种聚酯纤维掺量(0、0.3%、0.4%、0.5%)AC-13沥青混合料开展复盐(掺量配比为NaCl∶CaCl2∶CH2COONa=1∶1∶2)冻融循环劈裂试验,结果表明聚酯纤维掺量为0.4%时,沥青混合料水稳定最好;在最佳纤维掺量下制备5种替代率(0、25%、50%、75%、100%)钢渣粉沥青混合料,采用冻融劈裂抗拉强度比(freeze-thaw splitting tensile strength ratio,TSR)确定最佳钢渣粉替代率为75%,混合料水稳定性最佳;通过冻融腐蚀因子K评价沥青混合料的抗侵蚀性能,结果表明:聚酯纤维/钢渣粉沥青混合料的抗侵蚀性能最强,聚酯纤维沥青混合料次之,普通石灰岩沥青混合料最弱。通过电镜扫描(scanning electron microscope,SEM)、X射线衍射(X-ray diffraction,XRD)技术探索钢渣粉/聚酯纤维沥青混合料界面黏附作用的改性机理。微观分析表明:掺量为0.4%的聚酯纤维形成的纤维网状结构以及沥青、钢渣粉(75%的替代率)和矿粉三者存在界面能量作用可以很好地改善沥青混合料的水稳定性。

High-resolution X-ray flash radiography of Ti characteristic lines with multilayer Kirkpatrick–Baez microscope at the Shenguang-ⅡUpdate laser facility

High-resolution X-ray flash radiography of Ti characteristic lines with a multilayer Kirkpatrick-Baez microscope was developed on the Shenguang-Ⅱ(SG-Ⅱ)Update laser facility.The microscope uses an optimized multilayer design of Co/C and W/C stacks to obtain a high reflection efficiency of the Ti characteristic lines while meeting the precise alignment requirement at the Cu Kα line.The alignment method based on dual simulated balls was proposed herein,which simultaneously realizes an accurate indication of the center field of view and the backlighter position.The optical design,multilayer coatings,and alignment method of the microscope and the experimental result of Ti flash radiography of the Au-coned CH shell target on the SG-Ⅱ Update are described.

工科专业大型精密分析仪器运用能力培养体系的建设——透射电镜运用能力培养体系的建设实践

掌握大型精密分析仪器的核心科技,突破西方的技术壁垒,对创新型人才的培养至关重要。以透射电镜运用能力培养体系的建设实践为例,研究了工科专业大型精密分析仪器运用能力培养体系的建设方法。通过开发实物教学模型,结合计算机多媒体技术、网络技术和虚拟仿真技术搭建多媒体素质教育平台,借助MOOC和超星网络教学平台,建成了理论与实践深度融合,课内与课外、线上与线下有机结合的,以创新型人才培养为目标的透射电镜运用能力培养体系。透射电镜运用能力培养体系的建设经验可为其他大型精密分析仪器运用能力培养体系的建设提供借鉴与参考。

用偏光显微镜检测硝化棉的含氮量

建立了偏光显微镜测定硝化棉含氮量的新方法。采用色那蒙法测定了平均光程差。结果表明,当硝化棉含氮量为11.0%-13.8%时,光程差与含氮量线性相关,线性回归方程为w=-0.0466λ＋12.388,线性相关系数R=0.999 3。用硝化棉标准物质对新方法检测结果进行了验证,回收率为99.7%-100.2%,变异系数为0.15%-0.20%。新方法操作简单,结果准确,环境友好。

基于AFM表征的页岩孔隙特征及其与解析气量关系

页岩储层的孔隙结构影响着页岩气的储集特性。为了较为真实地反映样品表面孔隙三维结构,著者选用原子力显微镜研究页岩微-纳米孔隙特征。以重庆市涪陵地区焦页1井(JY1)和渝参4井(YC4)典型样品为研究对象,用原子力显微镜表征岩样的微观结构,获取岩样的三维形貌图,分析岩样的孔隙分布特征和储集空间特征,构建代表岩样孔隙特征的参数。分别比较相同井号不同井段之间的特征参数差异和不同井号之间的特征参数差异,从而定量描述岩样的形貌特征。结合样品提取现场解析气量数据,建立JY1、YC4样品的解析气量与特征参数之间的关系。结果表明:JY1样品的储集空间密集,孔隙占的空间相对多,其微观结构更有利于气体的吸附和储集;结合两口井取心现场解析页岩气量分析发现,JY1、YC4样品的空间起伏度FDI与现场解析气量均呈现正相关关系。

焊接气溶胶的 ATEM 分析方法

阐述了分析电子显微镜应用于焊接气溶胶研究的方法，并列举了分析结果，指出分析电子显微镜特别适宜于气溶胶粒子的形貌观察，放大倍数在５０００～２００００倍之间已可获得足够的信息．

表面吸附的微观机理研究进展

介绍了表面吸附的微观机理研究进展 ,着重阐述了表面吸附的微观机理研究的理论基础、现代表面吸附的分析技术、现代理论研究方法 ,并指出了现代表面吸附研究的发展趋势。

论显微构造地质学的解析性研究与教学

本文在解析构造学纲要的指导下,结合笔者在显微构造地质学领域的教学与研究实践,剖析了显微构造鉴定所能解决的解析构造学的科学问题,认为对于"构造的分期性和阶段性"、"表壳构造与深层次构造"等问题可发挥重要作用。教学体系方面,显微构造鉴定应分为光学显微构造地质学教学和电子显微构造地质学教学两个体系。结合实践提出了光学显微鉴定的循序渐进的实用训练方法。