In-situ investigation of atmospheric corrosion behavior of bronze under thin electrolyte layers using electrochemical technique

The atmospheric corrosion behavior of bronze under thin electrolyte layer （TEL） with different thicknesses was monitored using cathodic polarization curves, open circuit potential （OCP） and electrochemical impedance spectroscopy （EIS）. Cathodic polarization result indicates that the cathodic limiting current density increases with decreasing the TEL thickness. EIS result shows that the corrosion rate increases with decreasing the TEL thickness at the initial stage because the corrosion is dominated by the cathodic process, whereas after long immersion time, the corrosion degree with the TEL thickness is in the sequence of 150 μm 〉 310 μm〉 10μm ≈ bulk solution 〉 57 μm. The measurements of OCP and EIS present in-situ electrochemical corrosion information and their results are in good agreement with that of physical characterizations.

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 techniques to identify active sites for thermochemical conversion of CO_(2) over heterogeneous catalysts

The catalytic conversion of CO_(2) to fuels or chemicals is considered to be an effective pathway to mitigate the greenhouse effect. To develop new types of efficient and durable catalysts, it is critical to identify the catalytic active sites, surface intermediates, and reaction mechanisms to reveal the relationship between the active sites and catalytic performance. However, the structure of a heterogeneous catalyst usually dynamically changes during reaction, bringing a great challenge for the identification of catalytic active sites and reaction pathways. Therefore, in-situ/operando techniques have been employed to real-time monitor the dynamic evolution of the structure of active sites under actual reaction conditions to precisely build the structure–function relationship. Here, we review the recent progress in the application of various in-situ/operando techniques in identifying active sites for catalytic conversion of CO_(2) over heterogeneous catalysts. We systematically summarize the applications of various optical and X-ray spectroscopy techniques, including Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and X-ray absorption spectroscopy (XAS), in identifying active sites and determining reaction mechanisms of the CO_(2) thermochemical conversion with hydrogen and light alkanes over heterogeneous catalysts. Finally, we discuss challenges and opportunities for the development of in-situ characterization in the future to further enlarge the capability of these powerful techniques.

Dynamic phase transition behavior of a LiMn_(0.5)Fe_(0.5)PO_(4) olivine cathode material for lithium-ion batteries revealed through in-situ X-ray techniques

LiMn_(0.5)Fe_(0.5)PO_(4) has attracted great interest due to its good electrochemical performance and higher operating voltages.This has led to a greater than 30 percent higher energy density than for commercial Li Fe PO4 olivine cathodes.Understanding the phase transition behaviors and kinetics of this material will help researchers to design and develop next generation cathodes for Li-ion batteries.In this study,we investigated non-equilibrium phase transition behaviors in a LiMn_(0.5)Fe_(0.5)PO_(4) cathode material during charge–discharge processes by varying current rates(C-rates)using synchrotron in-situ X-ray techniques.These methods included wide angle X-ray scattering(in-situ WAXS)and X-ray absorption spectroscopy(in-situ XAS).The WAXS spectra indicate that the phase transition of LiMn_(0.5)Fe_(0.5)PO_(4) material at slow C-rates is induced by a two-phase reaction.In contrast,at a high C-rate(5 C),the formation of an intermediate phase upon discharge is clearly observed.Concurrently,the oxidation numbers of the redox reactions of Fe^(2+)/Fe^(3+)and Mn^(2+)/Mn^(3+)were evaluated using in-situ XAS.This combination of synchrotron in-situ X-ray techniques gives clear insights into the non-equilibrium phase transition behavior of a LiMn_(0.5)Fe_(0.5)PO_(4) cathode material.This new understanding will be useful for further developments of this highly promising cathode material for practical commercialization.

Techniques for in-situ stress measurement at great depth

Reliable information of in--situ stress state is necessary for the design andconstruction of most important rock projects. As most rock projects are getting deeper and deeper,traditional techniques of in--situ stress measurement are not very suitable. The current techniquesof in--situ stress measurement and their insufficiency for use at great depth are analyzed. Somebasic ideas of the development of new techniques and the improvement of current techniques for useat great depth are provided.

A Review of In‑Situ Techniques for Probing Active Sites and Mechanisms of Electrocatalytic Oxygen Reduction Reactions

Electrocatalytic oxygen reduction reaction(ORR)is one of the most important reactions in electrochemical energy technologies such as fuel cells and metal–O2/air batteries,etc.However,the essential catalysts to overcome its slow reaction kinetic always undergo a complex dynamic evolution in the actual catalytic process,and the concomitant intermediates and catalytic products also occur continuous conversion and reconstruction.This makes them difficult to be accurately captured,making the identification of ORR active sites and the elucidation of ORR mechanisms difficult.Thus,it is necessary to use extensive in-situ characterization techniques to proceed the real-time monitoring of the catalyst structure and the evolution state of intermediates and products during ORR.This work reviews the major advances in the use of various in-situ techniques to characterize the catalytic processes of various catalysts.Specifically,the catalyst structure evolutions revealed directly by in-situ techniques are systematically summarized,such as phase,valence,electronic transfer,coordination,and spin states varies.In-situ revelation of intermediate adsorption/desorption behavior,and the real-time monitoring of the product nucleation,growth,and reconstruction evolution are equally emphasized in the discussion.Other interference factors,as well as in-situ signal assignment with the aid of theoretical calculations,are also covered.Finally,some major challenges and prospects of in-situ techniques for future catalysts research in the ORR process are proposed.

Strategy &Techniques for Restoration of Healthy Aquaecosystem from Toxic Super Eutrophic Water Body

There are complex river-lake systems in the Taihu Lake catchment with total water surface area of 6174.7 km2, and population density of 1079/km2, including Taihu Lake water surface area of 2338 km2. The water systems in this catchment have healthy aquaecosystems during long history. However, in some riverlets in this catchment the water quality was estimated as “acute toxicity for higher organisms” and over standards for many heavy metal elements content;there were no any living plants and macro organisms in the water body, because there were developed a series of industry with abundant release of heavy metals and difficult decomposition organic chemical components along the riverlets during last decades. The even more serious situation was observed in sediments of the riverlets. How to restore such riverlet into a healthy aquaeosystem with abound plants and higher organisms? The main strategy and techniques are described in this paper as summarizing a report of engineering in a riverlet in Wuxi New District during last years, which leads to restore the aquaecosystem into a healthy one with abundant surface plant cultured on floating islands and observed living fish, lobster, frog, toad, mollusk and others in the riverlet. The main techniques are: 1) softwall buffer technic;2) floating eco-island technic by using which can culture any plant which can be cultured in solution;3) immobilized nitrogen cycle bacteria (INCB) technic;4) tattering esters and other big-molecule organic chemicals by using electronic pulse technic and photosensitization technic;5) mist spray facility technic for improving dissolved oxygen in deep water layers;6) technic for buffering and suppressing H2S release from water;7) the appropriate portion of surface with cultured plant to the total water surface area is about 1/3;8) Cress [Oenanthe Ljavanica (Bl.) DC.] and Myriophyllum verticilatum L. may be cultured in Taihu Lake catchment during the whole year as main plants with mosaic combination of other supplement plants in different seasons.

In-situ tracking CO_(2)-assisted isothermal-isobaric synthesis of selfassembled Bi-based photocatalyst using novel SAXS/XRD/XAFS combined technique

The synthetic path of a catalyst determines its morphology,species,and performance,and in-situ monitoring the catalyst formation process is fascinating and challenging.Herein,a newly developed synchrotron radiation smallangle X-ray scattering/X-ray diffraction/X-ray absorption fine structure(SAXS/XRD/XAFS)combined technique was used to in-situ monitor the isothermal-isobaric synthesis process of CO_(2)-assisted(BiO)_(2)CO_(3)(BOC)photocatalyst,and the atomic near-neighbor structure,crystalline structure and nanoscale particle size evolution with reaction time were simultaneously captured.The results show that both polyvinyl pyrrolidone and CO_(2)formed uniformly-distributed nano-sized scatterers in the Bi-based precursor solution,presenting short-range ordered structures to a certain extent.The as-prepared BOC catalytic particles underwent the evolution process of initial Bi(OH)3 precipitate,early-stage formed KBiO_(2)molecules,intermediate amorphous(BiO)4CO3(OH)2 nanoparticles,and finally crystallized flower-like BOC particles self-assembled by nanosheets.The flower-like BOC particles,Bi/BOC composite,and Bi nanospheres were further prepared with different synthesis paths.Flower-like BOC particles showed the best photocatalytic degradation performance of RhB.Scavenger experiment and theoretical calculation revealed the photocatalytic mechanisms of BOC.This work has implications for path-dependent synthesis of other catalysts.

Advance of in-situ stress measurement in China

In-situ stress is an essential parameter for design and construction of most engineering projects that involve excavation in rocks. Progress in in-situ stress measurement from the 1950s in China is briefly introduced. Stress relief by overcoring technique and hydraulic fracturing： technique are the two main techniques for in-situ stress measurement in China at present. To make them suitable for application at great depth and to increase their measuring reliability and accuracy, a series of techniques have been developed. Applications and achievements of in-situ stress measurement in Chinese rock engineering, including mining, geotechnical and hydropower engineering, and earthquake prediction, are introduced. Suggestions for further development of in-situ stress measurement are also proposed.

Synthesis, in-situ coating and characterization of scorodite with high leaching stability

To improve stability of scorodite,a method of simultaneous synthesis and in-situ coating of scorodite was proposed.Scorodite particles with polyhedral and raspberry-like morphologies were synthesized in an Fe(Ⅱ).As(Ⅴ).H2O system at 90℃and pH 1.5 by blowing oxygen gas into the system.When the initial Fe/As molar ratio exceeded 1:1,a coating of sulfate-containing iron(hydr)oxides formed on the surfaces of scorodite particles during synthesis.To evaluate the leaching stability of synthesized scorodite samples,toxicity characteristic leaching procedure(TCLP)tests were conducted at pH 4.93 for 60 h,and long-term leaching tests were conducted for 30.40 d within a pH range of 5.40.10.88.The leaching results indicated that the release of arsenic from scorodite was noticeably postponed by the coating,and the average arsenic concentrations in the leaching solutions were as low as 0.12 mg/L in the TCLP tests and lower than 0.5 mg/L in the long-term leaching tests.

Advances in in-situ characterizations of electrode materials for better supercapacitors

In past decades,the performance of supercapacitors has been greatly improved by rationalizing the electrode materials at the nanoscale.However,there is still a lack of understanding on how the charges are efficiently stored in the electrodes or transported across the electrolyte/electrode interface.As it is very challenging to investigate the ion-involved physical and chemical processes with single experiment or computation,combining advanced analytic techniques with electrochemical measurements,i.e.,developing in-situ characterizations,have shown considerable prospect for the better understanding of behaviors of ions in electrodes for supercapacitors.Herein,we briefly review several typical in-situ techniques and the mechanisms these techniques reveal in charge storage mechanisms specifically in supercapacitors.Possible strategies for designing better electrode materials are also discussed.

Reductive immobilization of Re(VⅡ)by graphene modified nanoscale zero-valent iron particles using a plasma technique

Technetium-99(~99Tc),largely produced by nuclear fission of ~235U or ~239Pu,is a component of radioactive waste.This study focused on a remediation strategy for the reduction of pertechnetate(Tc O_4^-)by studying its chemical analogue rhenium(Re(VⅡ))to avoid the complication of directly working with radioactive elements.Nanoscale zero-valent iron particles supported on graphene(NZVI/r GOs)from GOs-bound Fe ions were prepared by using a H_2/Ar plasma technique and were applied in the reductive immobilization of perrhenate(Re O_4^-).The experimental results demonstrated that NZVI/r GOs could efficiently remove Re from the aqueous solution,with enhanced reactivity,improved kinetics(50 min to reach equilibrium)and excellent removal capacity(85.77 mg/g).The results of X-ray photoelectron spectroscopy analysis showed that the mechanisms of Re immobilization by NZVI/r GOs included adsorption and reduction,which are significant to the prediction and estimation of the effectiveness of reductive Tc O_4^- by NZVI/r GOs in the natural environment.

Effect of In-Situ TiB₂Particle Addition on the Mechanical Properties of AA 2219 Al Alloy Composite

Aluminium alloy AA2219 was reinforced with TiB2 particles introduced in-situ by the saltmetal reaction technique. The microstructural examinations of the composites clearly reveal the formation of TiB2 particles with a hexagonal morphology. The addition of TiB2 particles results in increased mechanical properties, such as 0.2%YS, UTS and hardness. The improvement in mechanical properties is correlated to the microstructure.

In-situ Investigation of BBr_3/benzene Solution by Fourier Transformation Infrared Spectroscopy

By means of the in-situ Fourier transformation infrared spectroscopy（FTIR）, the properties of BBr3/ benzene solution, which is usually used as the reactant and solution to synthesize BN by benzene-thermal method, have been investigated. The results show that there are some side reactions between BBr3 and benzene： （1） BBr3 as an electron-deficient molecule reacts with benzene at room temperature; （2） below 100℃, substitution of Br atom for H atom of benzene（ring-H） dominates in BBr3/benzene solution; （3） cracking of benzene ring occurs at a temperature above 100℃; （4） decomposition of benzene molecules and formation of long-chain aliphatic compounds feature the spectra of BBr3/benzene solution collected at above 160℃, They are unfavor for BN to form when BBr3 is excessive in the synthesis of BN by benzene-thermal route. On the basis of the experimental results, a coordination reaction mechanism via a η^2-C6H6 binding mode in BBr3/benzene solution is suggested.

厌氧氨氧化菌固定化技术及其研究进展

厌氧氨氧化因其低能耗和高效脱氮而受到广泛关注,该技术在处理高氨氮、低碳氮比废水方面具有极大的应用价值。然而,自养型厌氧氨氧化菌倍增速度缓慢,污泥容易流失,且对生长环境的要求非常严格,导致厌氧氨氧化脱氮技术的应用受到限制。笔者总结了目前主要的4种厌氧氨氧化菌固定化技术的原理、优缺点以及适用场景,阐述了厌氧氨氧化菌固定化技术的最新研究进展,介绍了厌氧氨氧化菌的不同载体材料,并对厌氧氨氧化菌固定化技术的关键影响因素和最佳应用条件进行了总结,最后对厌氧氨氧化菌固定化技术现有研究的不足和未来可能的研究方向进行了总结和展望,以期为该技术的进一步发展提供一些研究思路。

A novel SAXS/XRD/XAFS combined technique for in-situ timeresolved simultaneous measurements

Synchrotron radiation based combined technique can provide multiple structural information simultaneously,which is an important development direction of structural detection.In this study,a novel small-angle X-ray scattering/X-ray diffraction/X-ray absorption fine structure(SAXS/XRD/XAFS)combined setup was constructed,where an area detector,a curved detector,and a point detector are,respectively,used for the measurements of SAXS,XRD,and XAFS signals.A detailed description about the combined setup was given.A minitype diamond detector coupled to a SAXS beamstop was used to record the transmitted X-ray intensity,making the scattering(SAXS and XRD)signal measurement compatible with the absorption(XAFS)signal measurement,avoiding mechanical switching.The two-way sampling strategy was used to acquire XAFS signals,shortening the non-counting time.The two-way and one-way sampling strategies were discussed.High-frequency sampling scheme was used to collect experimental signals,improving the measurement efficiency and signal-to-noise ratio.A detailed description and discussion about the high-frequency scheme were also given in this paper.Except the rotation of monochromator,there is no mechanical movement in measurements,time resolution may reach the level of seconds.Using this SAXS/XRD/XAFS combined setup,SAXS,XRD,and XAFS signals can be acquired simultaneously.With some in-situ sample environment system,the newlydeveloped combined technique can be used to track the structure evolution in complex fluids.During the formation processes of(BiO)2CO3 and ZnAPO-34 particles,the changes of in-situ experimental data with reaction time demonstrate that SAXS/XRD/XAFS combined technique is feasible to track the dynamic process.

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.

Spallation Process of Thermally Grown Oxides by In-Situ CCD Monitoring Technique

In cooling process of Fe-Cr-Al alloy oxidized at 1 300 ℃, the effect of cooling speed and exposure time on oxide spalled area fraction and successive variety of the spalled region were studied by investigating evolvement of the thermally grown oxide using in-situ CCD monitoring technique. The results showed that oxide spallation can be restrained by controlling cooling speed and the critical temperature drop of spallation initiation which is closely related to the oxide thickness or exposure time, and the spallation process of a little region may be described in more detail as two routes： from the oxide/substrate interface micro-decohesion, micro-buckles, buckle spreading, buckle crack to spallation and from the interface micro-decohesion, micro-buckles, buckle crack and spallation to the residual oxide decohesion and spallation.

新型微生物包埋颗粒固定化技术降解甲醛的研究

传统的甲醛去除方法效率低、易致二次污染,微生物法则操作复杂、易受环境影响。固定化微生物技术有生物量浓度高、处理效率高、条件简易等诸多优点。本实验对以甲醛为唯一碳源的微生物进行培养和鉴定,采用反复冻融聚乙烯醇和海藻酸钠制作包埋颗粒,评估其降解效果。在9天的降解后,经筛选培养的微生物包埋颗粒使甲醛含量降至初始值的52.1%。本研究通过固定化生物技术降解室内甲醛,在兼顾环保的同时提高了甲醛降解的效率和稳定性。

Generation of color-controllable room-temperature phosphorescence via luminescent center engineering and in-situ immobilization

Materials with controllable luminescence colors are highly desirable for numerous promising applications, however, the preparation of such materials, particularly with color-controllable room-temperature phosphorescence(RTP), remains a formidable challenge. In this work, we reported on a facile strategy to prepare color-controllable RTP materials via the pyrolysis of a mixture containing 1-(2-hydroxyethyl)-urea(H-urea) and boric acid(BA). By controlling the pyrolysis temperatures, the as-prepared materials exhibited ultralong RTP with emission colors ranging from cyan, green, to yellow. Further studies revealed that multiple luminescent centers formed from H-urea, which were in-situ embedded in the B2O3matrix(produced from BA) during the pyrolysis process. The contents of the different luminescent centers could be regulated by the pyrolysis temperatures, resulting in color-tunable RTP. Significantly, the luminescent center engineering and in-situ immobilization strategy not only provided a facile method for conveniently preparing color-controllable RTP materials, but also endowed the materials prepared at relatively lower temperatures with color-changeable RTP features under thermal stimulus. Considering their unique properties, the potential applications of the as-obtained materials for advanced anti-counterfeiting and information encryption were preliminarily demonstrated.