A review of in-situ high-temperature characterizations for understanding the processes in metallurgical engineering

For the rational manipulation of the production quality of high-temperature metallurgical engineering,there are many challenges in understanding the processes involved because of the black box chemical/electrochemical reactors.To overcome this issue,various in-situ characterization methods have been recently developed to analyze the interactions between the composition,microstructure,and solid-liquid interface of high-temperature electrochemical electrodes and molten salts.In this review,recent progress of in-situ hightemperature characterization techniques is discussed to summarize the advances in understanding the processes in metallurgical engineering.In-situ high-temperature technologies and analytical methods mainly include synchrotron X-ray diffraction(s-XRD),laser scanning confocal microscopy,and X-ray computed microtomography(X-rayμ-CT),which are important platforms for analyzing the structure and morphology of the electrodes to reveal the complexity and variability of their interfaces.In addition,laser-induced breakdown spectroscopy,high-temperature Raman spectroscopy,and ultraviolet-visible absorption spectroscopy provide microscale characterizations of the composition and structure of molten salts.More importantly,the combination of X-rayμ-CT and s-XRD techniques enables the investigation of the chemical reaction mechanisms at the two-phase interface.Therefore,these in-situ methods are essential for analyzing the chemical/electrochemical kinetics of high-temperature reaction processes and establishing the theoretical principles for the efficient and stable operation of chemical/electrochemical metallurgical processes.

In-situ/operando characterization techniques in lithium-ion batteries and beyond

Nowadays,in-situ/operando characterization becomes one of the most powerful as well as available means to monitor intricate reactions and investigate energy-storage mechanisms within advanced batteries.The new applications and novel devices constructed in recent years are necessary to be reviewed for inspiring subsequent studies.Hence,we summarize the progress of in-situ/operando techniques employed in rechargeable batteries.The members of this large family are divided into three sections for introduction,including bulk material,electrolyte/electrode interface and gas evolution.In each part,various energy-storage systems are mentioned and the related experimental details as well as data analysis are discussed.The simultaneous strategies of various in-situ methods are highlighted as well.Finally,current challenges and potential solutions are concluded towards the rising influence and enlarged appliance of in-situ/operando techniques in the battery research.

In-situ/operando characterization techniques for organic semiconductors and devices

The increasing demands of multifunctional organic electronics require advanced organic semiconducting materials to be developed and significant improvements to be made to device performance. Thus, it is necessary to gain an in-depth understanding of the film growth process, electronic states, and dynamic structure-property relationship under realistic operation conditions, which can be obtained by in-situ/operando characterization techniques for organic devices. Here, the up-todate developments in the in-situ/operando optical, scanning probe microscopy, and spectroscopy techniques that are employed for studies of film morphological evolution, crystal structures, semiconductor-electrolyte interface properties, and charge carrier dynamics are described and summarized. These advanced technologies leverage the traditional static characterizations into an in-situ and interactive manipulation of organic semiconducting films and devices without sacrificing the resolution, which facilitates the exploration of the intrinsic structure-property relationship of organic materials and the optimization of organic devices for advanced applications.

In-situ Characterization of Non-aqueous Nano-dispersion Systems by Freeze-etching TEM and Comparative Study with Laser Scattering Method

In-situ characterization of non-aqueous nano-dispersion systems（NANDS） by freeze-etching transmission electron microscope（FETEM） was reported.To improve just-for-once successive rate of specimen preparation and get good characterization results,an improving specimen preparation method of freezing etching was developed.Size,distribution and morphology of NANDS were directly visualized.Some information of particle dispersion feature and particle density can also be obtained.Reproductivity of the FETEM characterization is excellent.Comparing with laser scattering method,which is liable to give positive error especially for small size particle anchoring disperser,FETEM characterization can give more accurate measurement of particle size.Moreover,FETEM can give dispersion feature of nanoparticle in non-aqueous medium.

Fabrication and Characterizations of Mechanical Properties of Al-4.5%Cu/10TiC Composite by <i>In-situ</i>Method

Addition of reinforcement such as TiC, SiC, Al2O3, TiO2, TiN, etc. to Aluminium matrix for enhancing the mechanical properties has been a well established fact. In-situ method of reinforcement of the Aluminium matrix with ceramic phase like Titanium Carbide (TiC) is well preferred over the Ex-situ method. In the present investigation, Al-Cu alloy (series of 2014 Aluminium alloy) was used as matrix and reinforced with TiC using In-situ process. The Metal Matrix Composite (MMC) material, Al-4.5%Cu/10%TiC developed exhibited higher yield strength, ultimate strength and hardness as compared to Al-4.5%Cu alloy. Percentage increase in yield and ultimate tensile strengths were reported to be about 15% and 24% respectively whereas Vickers hardness increased by about 35%. The higher values in hardness indicated that the TiC particles contributed to the increase of hardness of matrix. Fractured surface of the tensile specimen of the composite material indicated presence of dimpled surface, indicating thereby a ductile type of fracture. During the fabrication of composite, reaction products such as Al3Ti, Al2Cu and Al3C4 were identified with various morphologies and sizes in metal matrix.

Application of in-situ characterization techniques in modern aqueous batteries

The development of high-performance aqueous batteries calls for an in-depth knowledge of their chargedischarge redox and failure mechanism,as well as a systematic understanding of the dynamic evolution of microstructure,phase composition,chemical composition,and local chemical environment of the materials for battery.In-situ characterization technology is expected to understand and reveal the problems faced by aqueous rechargeable batteries,such as the dissolution of electrode materials,the growth of metal negative electrode dendrites,passivation,corrosion,side reactions and a series of problems.Based on this,typical in-situ characterization techniques and their basic mechanisms are summarized,including in-situ optical visualization,in-situ microscopy techniques(in-situ scanning electron microscopy(SEM),in-situ transmission electron microscopy(TEM)),in-situ X-ray techniques(in-situ X-ray diffraction(XRD),in-situ X-ray photoelectron spectroscopy(XPS),in-situ near-edge structural X-ray absorption spectroscopy(XANES)),and in-situ spectroscopy techniques(in-situ Raman spectroscopy,in-situ Fourier transform infrared(FTIR)).Moreover,some emerging techniques concerning aqueous battery research,especially gas evolution and materials dissolution issues,such as in-situ electrochemical quartz crystal microbalance(EQCM).in-situ fiber-optic sensing,in-situ gas chromatography(GC) are introduced.At last,the applications of advanced in-situ characterizations in future research of aqueous batteries are emphasized and discussed,along with some of the remaining challenges and possible solutions.

In-situ SEM characterization of fracture mechanism of TiB/Ti-2Al-6Sn titanium matrix composites after electroshocking treatment

In this article,in-situ scanning electron microscope characterization of the tensile properties of TiB/Ti-2Al-6Sn titanium matrix composite(TMC)was conducted before and after electroshocking treatment(EST).After EST,the tensile strength increased by 113.2 MPa.The effect of EST on the tensile strength and fracture behavior of TiB was investigated using in-situ characterization of the fracture morphology and crack propagation path of the matrix and TiB.Before EST,TiB fracture introduced cracks that extended into the matrix,resulting in material failure.After EST,the refined TiB improved the bearing capacity of the matrix,thereby improving TMC strength.Moreover,after EST,the cracks were introduced into the matrix,and resulting the fracture of matrix first.With an increase in the external load,cracks in the matrix were observed to propagate to TiB,and the refined TiB was fractured,detached,and pulled out,resulting in the formation of pores.Analyzing the propagation path of the main crack after EST showed that the deflection angle of the main crack increased.The micro structure of the fracture surface indicated that the fracture of the matrix was plastic,whereas that of TiB was brittle.After EST,the size and area of the dimples increased,confirming the increase in plasticity.The results revealed that the comprehensive mechanical properties of TiB/Ti-2Al-6Sn improved after EST.Hence,EST is an efficient method for tailoring the micro structures and mechanical properties of TMCs.

Individualized Pixel Synthesis and Characterization of Combinatorial Materials Chips

Conventionally, an experimentally determined phase diagram requires studies of phase formation at a range of temperatures for each composition, which takes years of effort from multiple research groups. Combinatorial materials chip technology, featuring high-throughput synthesis and characterization, is able to determine the phase diagram of an entire composition spread of a binary or ternary system at a single temperature on one materials library, which, though significantly increasing efficiency, still requires many libraries processed at a series of temperatures in order to complete a phase diagram. In this paper, we propose a "one-chip method" to construct a complete phase diagram by individually synthesizing each pixel step by step with a progressive pulse of energy to heat at different temperatures while monitoring the phase evolution on the pixel in situ in real time. Repeating this process pixel by pixel throughout the whole chip allows the entire binary or ternary phase diagram to be mapped on one chip in a single experiment. The feasibility of this methodology is demonstrated in a study of a Ge-Sb-Te ternary alloy system, on which the amorphouscrystalline phase boundary is determined.

Recent progress of in-situ characterization of LiNi_(1−x−y)Co_(x)Mn_(y)O_(2) cathodes for lithium metal batteries: A mini review

In the context of the gradual popularity of electric vehicles(EVs),the development of lithium battery systems with high energy density and power density is regarded as the foremost way to improve the range of EVs.LiNi_(1-x-y)Co_(x)Mn_(y)O_(2)(NCM)cathodes have been the focus of researchers due to their high energy density,excellent power performance,and low-temperature resistance.However,the elaboration of the decay mechanism of NCM cathode based on lithium metal batteries(LMBs)is still being restricted to the primary level.In the past decades,the development and application of advanced in-situ characterization tools have facilitated researchers'understanding of the internal operation mechanism of batteries during charging and discharging.In this minireview,the latest progress of in-situ observation of the NCM cathode by X-ray diffraction(XRD),fourier transform infrared(FT-IR)spectroscopy,Raman spectroscopy,atomic force microscopy(AFM),transmission electron microscope(TEM),optical microscope,and other characterization tools is summarized.The mechanisms of structural degradation,cathode-electrolyte interfaces(CEIs)composition,and dynamic changes of NCM,electrolyte breakdown,and gas production are elaborated.Finally,based on the existing research progress,the opportunities and challenges for future in-situ characterization technology in the study of the mechanism of LMBs are discussed in depth.Therefore,the purpose of this minireview is to summarize recent work that focuses on the outstanding application of in-situ characterization techniques in the mechanistic study of LMBs,and pointing the way to the future development of high energy density and power density LMBs systems.

Full life cycle characterization strategies for spatiotemporal evolution of heterogeneous catalysts

The sustainable development of the chemical industry requires novel and efficient catalysts and catalytic processes,especially eco-friendly and intrinsically safe processes.The idea is to improve the selectivity,activity,and stability of the catalyst in an appropriate reactor.Therefore,it is of great academic and industrial significance to conduct in-situ characterization of a working catalyst while testing its catalytic performance.This is beneficial for a comprehensive study on the dynamic evolution of the catalyst structure under real conditions,deepening the understanding of the structure-performance relationship of catalysts,and providing a scientific basis for the development of future generation catalytic technology.Thus far,it is still a great challenge to realize full life cycle characterization of heterogeneous catalysts from catalyst formation and function to deactivation under real world conditions.In this mini review,we summarize the characterization strategies for heterogeneous catalysts,using zeolite,metal,and metal oxide catalysts as typical examples.The research strategies for the approximation of industrial conditions,multi-scale in-situ characterization devices,and computational modeling of realistic conditions should provide insight for the research and development of industrial catalysis.

CHARACTERIZATION OF VELOCITY SINGULARITY AND SUPPRESSION OF NOISE

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Spectroscopy framework and review of characterization of energy resource sites

Site characterization and rapid reliable identification of energy resources play a key role for future efficient energy production.Over the last several decades,many laboratory and in-situ techniques were developed to qualitatively and quantitatively characterize the sites and minerals.Despite the advancements,there are still many challenges associated with exploration,rapid detection,and spatial interpolation of the energy resources within a site.Spectroscopy techniques offer solutions to the current ongoing efforts on site characterization,exploration and collection of resources,quality control monitoring during production,and reclamation of the production sites due to environmental contamination.Spectral analysis has shown great promise in providing in-situ measurements that are comparable to arduous laboratory physio-chemical analysis.Spectroscopy is a fairly new technology in some sectors and has seen limited use but has shown great potential in exceeding the minimum standards implemented.This paper presents review of the current spectroscopy techniques that have been used in the agriculture,landfill,nuclear power,mining,and ground contamination industries with respect to the production of energy.A general overview of how spectral analysis techniques are being used to benefit each of these sectors along with some of the drawbacks associated with each is presented.Three frameworks including basic process,operation flowchart,minimum number of tests to be performed,and information on spatial interpolation analysis are presented.These frameworks along with the basic processes can be implemented for characterization of energy resource sites。

页岩储层多尺度天然裂缝表征与三维地质建模:以四川盆地平桥构造带五峰组龙马溪组页岩为例

天然裂缝是页岩储层重要的储集空间和渗流通道,查明天然裂缝类型及其空间展布特征是页岩气勘探开发的重要基础之一。基于地震、露头、岩心观察、测井和微观测试分析等资料,重点考虑裂缝对页岩气富集高产的控制作用,将页岩储层天然裂缝分为大尺度、中小尺度和微尺度3类,明确了各尺度裂缝表征与建模方法和应用效果。(1)大尺度裂缝通过叠后地震属性表征,中小尺度裂缝以岩心、成像测井和地震属性预测相结合的方法表征,微尺度裂缝通过岩心描述、扫描电镜观测等方法表征,明确了各尺度裂缝发育密度、开度、产状和充填状况等特征。(2)大尺度裂缝通过输入叠后地震属性表征参数,采用确定性建模方法建立大尺度裂缝DFN模型;中小尺度裂缝以单井成像测井解释数据为先验信息,以多信息融合的裂缝概率体为空间约束建立裂缝密度体,采用随机模拟方法建立中小尺度裂缝DFN模型;微尺度裂缝建模以微观测试分析获取的微裂缝参数为基础,井资料与TOC等主控因素属性体结合建立微裂缝密度体,采用随机模拟方法建立微裂缝DFN模型。(3)以四川盆地平桥构造带页岩气为例,开展了页岩储层不同尺度裂缝表征与三维地质建模工作,明确了不同尺度裂缝的发育位置、规模和产状特征,刻画了不同尺度裂缝的空间位置、倾角、方位角、几何尺寸、发育密度等属性特征,形成了多尺度页岩储层天然裂缝表征与建模技术,为页岩气藏数值模拟提供了较可靠的模型依据。该方法建立的平桥构造带页岩储层三维地质模型及其模拟结果与地质认识、生产数据吻合较好,对页岩气田开发具有参考价值。

复合固体推进剂损伤行为的多尺度研究进展

从微观、细观、宏观尺度和跨尺度4个方面,对复合固体推进剂损伤行为的研究进展进行了梳理,重点综述了不同尺度下损伤的观测和表征方法、损伤阈值的确定方法、损伤演化模型的构建方法、损伤数值模拟方法及宏细观跨尺度分析方法,并在此基础上针对当前研究中存在的若干不足,展望了需进一步重点开展研究的方向:拓宽微观尺度上开展复合固体推进剂损伤行为数值模拟时考虑的影响因素的范围,并从多个方面加强与试验研究结论的验证;提高细观尺度上损伤观测试验的能力、损伤演化模型的表征水平和损伤数值模拟的计算精度;提高宏观尺度上损伤识别测试试验的检测精度、损伤阈值确定方法的精确性和损伤演化模型的预测能力;在形成微细宏观单一尺度上复合固体推进剂损伤行为研究的标准规范的基础上,进一步建立推进剂损伤行为跨尺度研究的理论方法体系。

Remote plasma enhanced cyclic etching of a cyclosiloxane polymer thin film

The continuous evolution of chip manufacturing demands the development of materials with ultra-low dielectric constants.With advantageous dielectric and mechanical properties,initiated chemical vapor deposited(iCVD)poly(1,3,5-trimethyl-1,3,5-trivinyl cyclotrisiloxane)(pV3D3)emerges as a promising candidate.However,previous works have not explored etching for this cyclosiloxane polymer thin film,which is indispensable for potential applications to the back-end-of-line fabrication.Here,we developed an etching process utilizing O2/Ar remote plasma for cyclic removal of iCVD pV3D3 thin film at sub-nanometer scale.We employed in-situ quartz crystal microbalance to investigate the process parameters including the plasma power,plasma duration and O2 flow rate.X-ray photoelectron spectroscopy and cross-sectional microscopy reveal the formation of an oxidized skin layer during the etching process.This skin layer further substantiates an etching mechanism driven by surface oxidation and sputtering.Additionally,this oxidized skin layer leads to improved elastic modulus and hardness and acts as a barrier layer for protecting the bottom cyclosiloxane polymer from further oxidation.

Electrocatalysts with atomic-level site for nitrate reduction to ammonia

Ammonia(NH_(3))is an important raw material for modern agriculture and industry,being widely demanded to sustain the sustainable development of modern society.Currently,the industrial production methods of NH_(3),such as the traditional Haber-Bosch process,have drawbacks including high energy consumption and significant carbon dioxide emissions.In recent years,the electrocatalytic nitrate reduction reaction(NO_(3)RR)powered by intermittent renewable energy sources has gradually become a multidisciplinary research hotspot,as it allows for the efficient synthesis of NH_(3)under mild conditions.In this review,we focus on the research of electrocatalysts with atomic-level site,which have attracted attention due to their extremely high atomic utilization efficiency and unique structural characteristics in the field of NO_(3)RR.Firstly,we introduce the mechanism of nitrate reduction for ammonia synthesis and discuss the in-situ characterization techniques related to the mechanism study.Secondly,we review the progress of the electrocatalysts with atomic-level site for nitrate reduction and explore the structure-activity relationship to guide the rational design of efficient catalysts.Lastly,the conclusions of this review and the challenges and prospective of this promising field are presented.

纤维缠绕复合材料损伤演化多尺度表征方法构建

针对复合材料多尺度表征中以细观到宏观力学性能预测为主的问题,发展了包含细观到宏观结构力学性能预测和宏观到细观组分损伤演化表征的纤维缠绕复合材料损伤演化多尺度表征方法。通过确定纤维缠绕复合材料组分本构及力学参数,完成基于细观RFDRVE(Random fiber distributions representative volume element)的单向复合材料力学参数预测,进而实现了纤维缠绕复合材料NOL环的宏观力学性能预测。而后,通过分析NOL环宏观破坏情况,将损伤区域应变加载至RFDRVE,得到NOL环的细观损伤演化情况,并结合扫描电镜观测了细观损伤演化形貌。结果表明,不同缠绕张力下NOL环细观到宏观预测拉伸强度与平均试验拉伸强度的最大误差仅5.08%,且宏观到细观损伤分析能够表征NOL环细观组分上出现的纤维断裂、基体断裂和纤维-基体界面破坏。纤维缠绕复合材料损伤演化多尺度表征方法能实现细观到宏观结构力学性能预测和宏观到细观组分损伤演化表征。

复合材料壳体结构损伤演化多尺度表征与强度智能预测进展

随着计算机算力的发展和数值模拟技术的日趋成熟,以跨宏细观参数传递为主的复合材料多尺度表征计算应运而生,得到了世界各国学者和研究人员的关注。本文基于纤维缠绕复合材料壳体结构损伤演化研究,详述了在单向纤维增强复合材料宏观工程弹性常数预测、纤维随机分布代表性体积元高效建模、纤维增强复合材料损伤演化多尺度表征与强度预测、机器学习在纤维增强复合材料领域应用方面的进展。最后,对未来发展趋势进行了预测。

Pd-based nanocatalysts for oxygen reduction reaction:Preparation,performance,and in-situ characterization

Electrochemical energy devices such as fuel cells have received extensive concern in recent decades.However,the commercial applications of fuel cells have been restricted by the slow kinetics of oxygen reduction reaction(ORR).Pd-based fuel cell catalysts are strong candidates for enhanced ORR activities,especially under alkaline conditions.Therefore,extensive exploration has been made to improve the performance of Pd-based nano-catalysts for oxygen reduction reaction.This paper reviews the research progress of preparation,electrocatalytic performance,and in-situ characterization of various Pd-based oxygen reduction catalysts,from zero-dimensional nanoparticles,to one-dimensional nanowires,to two-dimensional nanosheets,and to Pd single-atom catalysts.It may provide some help for improving the activity of Pd-based catalysts and understanding the reaction mecha-nisms and structure-activity relationships.

Comprehensive kinetostatic modeling and morphology characterization of cable-driven continuum robots for in-situ aero-engine maintenance

In-situ maintenance is of great significance for improving the efficiency and ensuring the safety of aero-engines.The cable-driven continuum robot(CDCR)with twin-pivot compliant mechanisms,which is enabled with flexible deformation capability and confined space accessibility,has emerged as a novel tool that aims to promote the development of intelligence and efficiency for in-situ aero-engine maintenance.The high-fidelity model that describes the kinematic and morphology of CDCR lays the foundation for the accurate operation and control for in-situ maintenance.However,this model was not well addressed in previous literature.In this study,a general kinetostatic modeling and morphology characterization methodology that comprehensively contains the effects of cable-hole friction,gravity,and payloads is proposed for the CDCR with twin-pivot compliant mechanisms.First,a novel cable-hole friction model with the variable friction coefficient and adaptive friction direction criterion is proposed through structure optimization and kinematic parameter analysis.Second,the cable-hole friction,all-component gravities,deflection-induced center-of-gravity shift of compliant joints,and payloads are all considered to deduce a comprehensive kinetostatic model enabled with the capacity of accurate morphology characterization for CDCR.Finally,a compact continuum robot system is integrated to experimentally validate the proposed kinetostatic model and the concept of in-situ aero-engine maintenance.Results indicate that the proposed model precisely predicts the morphology of CDCR and outperforms conventional models.The compact continuum robot system could be considered a novel solution to perform in-situ maintenance tasks of aero-engines in an invasive manner.