The development of azobenzene photoisomerization materials marks a pivotal advancement in solar-thermal conversion technologies.Their properties and performance,explored through comprehensive characterization,are vita...The development of azobenzene photoisomerization materials marks a pivotal advancement in solar-thermal conversion technologies.Their properties and performance,explored through comprehensive characterization,are vital for further progress.Despite extensive research in this area,a detailed summary of characterization methods for azobenzene materials remains largely unexplored.This review addresses this gap by detailing structural and performance characterization techniques.It provides an in-depth overview of various experimental methods,highlighting their objectives,operational mechanics,and practical applications.This detailed review sheds light on the complex relationship between the materials'structure and their performance.Moreover,the review presents a critical analysis of these methods,assessing their strengths and limitations.By doing so,it highlights the revolutionary potential of azobenzene materials in the realm of solar energy conversion and underscores their significance in fostering sustainable energy solutions.展开更多
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...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.展开更多
The development of high-performance lithium ion batteries requires the discovery of new materials and the optimization of key components.By contrast with traditional one-by-one method,high-throughput method can synthe...The development of high-performance lithium ion batteries requires the discovery of new materials and the optimization of key components.By contrast with traditional one-by-one method,high-throughput method can synthesize and characterize a large number of compositionally varying samples,which is able to accelerate the pace of discovery,development and optimization process of materials.Because of rapid progress in thin film and automatic control technologies,thousands of compounds with different compositions could be synthesized rapidly right now,even in a single experiment.However,the lack of rapid or combinatorial characterization technologies to match with high-throughput synthesis methods,limit the application of high-throughput technology.Here,we review a series of representative highthroughput characterization methods used in lithium batteries,including high-throughput structural and electrochemical characterization methods and rapid measuring technologies based on synchrotron light sources.展开更多
At present,blast furnace ironmaking is still the main process for producing molten iron,and sinters are the main raw material for blast furnace ironmaking.A sinter with good metallurgical performance can not only ensu...At present,blast furnace ironmaking is still the main process for producing molten iron,and sinters are the main raw material for blast furnace ironmaking.A sinter with good metallurgical performance can not only ensure smooth operation of the blast furnace but also reduce the blast furnace fuel ratio and increase the molten iron production.Structure is the most important factor affecting the metallurgical properties of the sinter.Thus,the research progress of sinter pore and mineral phase structures was reviewed and the mechanism by which they influence sinter properties was expounded.Multiscale characterization methods for the sinter and their advantages and disadvantages were introduced,and the future research direction of sinter was discussed.展开更多
Ethinyl estradiol(EE) as a contraceptive,(17α)-19-nopregna-1,3,5-(10)-trien-20-yne-3,17-diol(formula: C(20)H(24)O2, molecular weight: 296.4, CAS number: 57-63-6), is known to have different pseudo-poly...Ethinyl estradiol(EE) as a contraceptive,(17α)-19-nopregna-1,3,5-(10)-trien-20-yne-3,17-diol(formula: C(20)H(24)O2, molecular weight: 296.4, CAS number: 57-63-6), is known to have different pseudo-polymorphic forms. Some EE polymorphs have been synthesized by means of physical or chemical methods, characterized by X-ray powder diffraction(XRPD), thermogravimetric(TG), differential scanning calorimetry(DSC) and IR spectra. Dissolution profile was tested by high performance liquid chromatography(HPLC). Meanwhile, the crystal structure of the new EE solvate(formamide) was characterized by single-crystal X-ray structure analysis(SXRD). The results confirmed that EE existed polymorphism. Five crystal forms of EE were presented and two of them were reported firstly. Furthermore, five polymorphs' dissolution curves were drawn and they could be identified by several analysis methods. Our study on polymorphs of EE could provide a variety of crystal material composition, preparation methods and solubility.展开更多
A photovoltaic technology historically goes through two major steps to evolve into a mature technology. The first step involves advances in materials and is usually accompanied by the rapid improvement of power conver...A photovoltaic technology historically goes through two major steps to evolve into a mature technology. The first step involves advances in materials and is usually accompanied by the rapid improvement of power conversion efficiency. The second step focuses on interfaces and is usually accompanied by significant stability improvement. As an emerging generation of photovoltaic technology, perovskite solar cells are transitioning to the second step of their development when a significant focus shifts toward interface studies and engineering. While various interface engineering strategies have been developed, interfacial characterization is crucial to show the effectiveness of interfacial modification. Here, we review the characterization techniques that have been utilized in studying interface properties in perovskite solar cells. We first summarize the main roles of interfaces in perovskite solar cells, and then we discuss some typical characterization methodologies for morphological, optical,and electrical studies of interfaces. Successful experiences and existing problems are analyzed when discussing some commonly used methods. We then analyze the challenges and provide an outlook for further development of interfacial characterizations. This review aims to evoke strengthened research devotion on novel and persuasive interfacial engineering.展开更多
A simple creep testing method is presented which involves using coiled specimens. With this method, a single experiment can give all the data required for a plot of strain rate versus stress. The value of the stress-e...A simple creep testing method is presented which involves using coiled specimens. With this method, a single experiment can give all the data required for a plot of strain rate versus stress. The value of the stress-expo-nent of room temperature steady-state creep a Pb-61. 5wt %Sn solder was measured in this way to be 1. 06,aselected from a diffusion creep mechanism.展开更多
In order to establish the quantitative relationship between equivalent strain and the performance index of the deformed material within the range of certain passes for equal channel angular processing (ECAP), a new ...In order to establish the quantitative relationship between equivalent strain and the performance index of the deformed material within the range of certain passes for equal channel angular processing (ECAP), a new approach to characterize the equivalent strain was proposed. The results show that there exists better accordance between mechanical property (such as hardness or strength) and equivalent strain after rolling and ECAP in a certain range of deformation amount, and Gauss equation can be satisfied among the equivalent strain and the mechanical properties for ECAP. Through regression analysis on the data of hardness and strength after the deformation, a more generalized expression of equivalent strain for ECAP is proposed as:ε=k0exp[-(k1M-k2)^2], where M is the strength or hardness of the material, k1 is the modified coefficient (k1∈ (0, 1)), ko and k2 are two parameters dependent on the critical strain and mechanical property that reaches saturation state for the material, respectively. In this expression the equivalent strain for ECAP is characterized novelly through the mechanical parameter relating to material property rather than the classical geometry equation.展开更多
Validating a method of analysis goes through different steps, which aims at testing the normality of measurements distribution, estimating the uncertainty of the components of a measurement (i.e., accuracy and correc...Validating a method of analysis goes through different steps, which aims at testing the normality of measurements distribution, estimating the uncertainty of the components of a measurement (i.e., accuracy and correctness), and finally, define the control tests of non degradation of the method performances. This paper outlines the steps for validating a biological method of analysis. It involves the construction of an experimental design, a statistical model, and the preparation of an interne laboratory reference material (pilot vaccine). The latter is used to study the impact of deviation and variation factors, in order to, optimize the analytical method, to evaluate the bias (random error), and to calculate the uncertainty of measurement, and make the control charts. This method is applied in the titration of live viral vaccines of Gumboro disease on chicken's embryos fibroblasts. The experimental results show that potential influence factors related to the titration method had no significant influence on the obtained results. Taking into account these results, an operating mode has been elaborated. The finalized method proved to be faithful to standard deviation of repeatability and reproducibility of 0.21 and 0.22, respectively, with a confidence level of 95%. The calculated uncertainty of measurement is equal to 0.2, which represents the average error level of a titer. A homogeneous stock of interne laboratory reference vaccine (MRIL), with an average titer of 5.9 log DIT 50, was produced and the control chart set in away to provide the laboratory with an important tool of control and monitoring of the viral titers evolution in time, as well as, the mastery of the validated titration method performances.展开更多
The compounds of iron substituted yttrium oxide systems have been prepared for the importance in the field of magneto electric materials.The polycrystalline samples of Y2–xFexO3–y(x=0.1,0.2) were prepared by solid-s...The compounds of iron substituted yttrium oxide systems have been prepared for the importance in the field of magneto electric materials.The polycrystalline samples of Y2–xFexO3–y(x=0.1,0.2) were prepared by solid-state reaction method.The single-phase formation of these compounds was confirmed by X-ray diffraction studies.It was found that the samples crystallized in tetragonal phase and the lattice parameters were calculated as a=1.0559(7) nm,c=1.0832(9) nm for Y1.9Fe0.1O3–y and a=1.0545(6) nm,c=1.0841(8)...展开更多
With the advancement of secondary batteries,interfacial properties of electrode materials have been recognized as essential factors to their electrochemical performance.However,the majority of investigations are devot...With the advancement of secondary batteries,interfacial properties of electrode materials have been recognized as essential factors to their electrochemical performance.However,the majority of investigations are devoted into advanced electrode materials synthesis,while there is insufficient attention paid to regulate their interfaces.In this regard,the solid electrolyte interphase(SEI)at anode part has been studied for 40 years,already achieving remarkable outcomes on improving the stability of anode candidates.Unfortunately,the study on the cathode electrolyte interfaces(CEI)remains in infancy,which constitutes a potential restriction to the capacity contribution,stability and safety of cathodes.In fact,the native CEI generally possesses unfavorable characteristics against structural and compositional stability that requires demanding optimization strategies.Meanwhile,an in-depth understanding of the CEI is of great significance to guide the optimization principles in terms of composition,structure,growth mechanism,and electrochemical properties.In this literature,recent progress and advances of the CEI characterization methods and optimization protocols are summarized,and meanwhile the mutually-reinforced mechanisms between detection and modification are explained.The criteria and the potential development of the CEI characterization are proposed with insights of novel optimization directions.展开更多
Dye-sensitized solar cell (DSSC) is one of the most rapidly developed solar cells in the past 20 years. Many characterization methods have been employed for further understanding the operational details of the photo...Dye-sensitized solar cell (DSSC) is one of the most rapidly developed solar cells in the past 20 years. Many characterization methods have been employed for further understanding the operational details of the photo- electric conversion in DSSC as well as the evaluation of cell performance. Electrochemical methods have become pow- erful tools for studying the charge transfer and interfacial process. In this review, we introduce and explain the various electrochemical methods used to characterize and analyze DSSC, including current-voltage (I-V) scan measurement, cyclic voltammetry, electrochemical impedance spec- troscopy, intensity-modulated photocurrent spectroscopy, and intensity-modulated photovoltage spectroscopy. In ad- dition, some applications were provided as samples to elucidate electron transfer kinetics, energy levels and electrocatalytic activity of the materials used in DSSC.展开更多
Multiuser online system is useful, but the administrator must be nervous at security problem. To solve this problem, the authors propose applying signature verification to multiuser online system. At the authors' res...Multiuser online system is useful, but the administrator must be nervous at security problem. To solve this problem, the authors propose applying signature verification to multiuser online system. At the authors' research, they attempt adding signature verification function based on DP (Dynamic Programming) matching to existing multiuser online kanji learning system. In this paper, the authors propose the construction of the advance system and methods of signature verification, and evaluate performance of those signature verification methods that difference is combination of using features. From signature verification's experimental results, the authors adopted to use writing velocity and writing speed differential as using feature to verify the writer for the system. By using signature database which is construct with 20 genuine signatures and 20 forged signatures with 40 writers and written mostly by English or Chinese literal, experimental results of signature verification records 12.71% as maximum EER (Equal Error Rate), 6.00% as minimum EER, and 8.22% as average EER. From mentioned above, the authors realized to advance the reliability and usefulness of the multiuser online kanji learning system.展开更多
Hydroxyapatite-magnesium titanate composite nanopowders have been developed using a mechanothermal process.Thermal treatment of the milled powders at 700℃resulted in the formation of HAp/MgTiO_(3)-MgO nanocomposite.X...Hydroxyapatite-magnesium titanate composite nanopowders have been developed using a mechanothermal process.Thermal treatment of the milled powders at 700℃resulted in the formation of HAp/MgTiO_(3)-MgO nanocomposite.X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),and energy dispersive X-ray spectroscopy(EDX)techniques were utilized to characterize the synthesized powders.The results revealed that the dominant phases after mechanical activation were hydroxyapatite,anatase(TiO_(2))and periclase(MgO);while after thermal annealing process at 700℃,hydroxyapatite along with geikielite(MgTiO_(3))and periclase(MgO)were the major phases.Based on the XRD analysis,the evaluation of structural features of the samples indicated that the average crystallite sizes of hydroxyapatite after 10 h of milling and subsequent thermal treatment at 700℃were about 21 nm and 34 nm,respectively.Microscopic observations illustrated that the synthesized powders contained large agglomerates which consisted of significantly finer particles with spheroidal morphology.It is concluded that the mechanothermal method can be used to produce hydroxyapatite-based nanocomposite with appropriate structural and morphological features.展开更多
ZnO/graphene oxide(ZnO/GO) composite material,in which ZnO nanoparticles were densely coated on the GO nanosheets,was successfully prepared by an improved two-step method and characterized by IR, XRD,TEM,and UV-vis ...ZnO/graphene oxide(ZnO/GO) composite material,in which ZnO nanoparticles were densely coated on the GO nanosheets,was successfully prepared by an improved two-step method and characterized by IR, XRD,TEM,and UV-vis techniques.The improved photocatalytic property of the ZnO/GO composite material,evaluated by the photocatalytic degradation of methyl orange(MO) under UV irradiation,is ascribed to the intimate contact between ZnO and GO,the enhanced adsorption of MO,the quick electron transfer from excited ZnO particles to GO sheets and the activation of MO molecules viaπ-πinteraction between MO and GO.展开更多
A low-frequency multi-mode ultrasonic Lamb wave method suitable for character- izing the thickness, the density and the elastic constants of the ultra-thin transversely isotropic laminate composite is presented. The &...A low-frequency multi-mode ultrasonic Lamb wave method suitable for character- izing the thickness, the density and the elastic constants of the ultra-thin transversely isotropic laminate composite is presented. The 'ultra-thin' here means that the thickness of the plate is much less than the wavelength of the ultrasonic wave so that the echoes from the front and back faces of the plate can't be separated in the time domain. The dispersion equations for the low frequency ultrasonic Lamb waves with the propagation directions parallel and vertical to the fiber direction are derived. In conjunction with the least square algorithm method, the secant algorithm is used to estimate the parameters of the ultra-thin fiber-reinforced composite layer. The evaluation errors and the sensitivity of the method to different paramters of the thin composite are analyzed. The technique has been used to characterize the ultra-thin grass fiber reinforced PES composite with thickness down to ten percents of the ultrasonic wavelength. It is observed that the agreement between the nominal and the estimation values is reasonably good.展开更多
Automatic identification of characters marked on billets is very important for steelworks to achieve manu- facturing and logistics informatization management. Due to the presence of adhesions, fractures, blurs, and ot...Automatic identification of characters marked on billets is very important for steelworks to achieve manu- facturing and logistics informatization management. Due to the presence of adhesions, fractures, blurs, and other problems in characters painted on billets, character recognition accuracy with machine vision is relatively low, and hardly meets practical application requirements. To make the character recognition results more reliable and accu- rate, an identification results classification and post-pro- cessing method has been proposed in this paper. By analyzing issues in the image segmentation and recognition stage, the recognition result classification model, based on character encoding rules and recognition confidence, is built, and the character recognition results can be classified as correct, suspect, or wrong. In the post-processing stage, a human-machine-cooperation mechanism with a post- processing interface is designed to eliminate error infor- mation in suspect and wrong types. The system was developed and experiments conducted with images acquired in an iron and steel factory. The results show the character recognition accuracy to be approximately 89% using the character recognizer. However, this result cannot be directly applied in information management systems. With the proposed post-processing method, a human worker will query the suspect and wrong results classified by the system, determine whether the result is correct or wrong, and then, correct the wrong result through the post-processing interface. Using this method, the character recognition accuracy ultimately improves to 99.4%. Thus, the results will be more reliable applied in a practical system.展开更多
The rapid evolution of flexible electronic devices promises to revolutionize numerous fields by expanding the applications of smart devices.Nevertheless,despite this vast potential,the reliability of these innovative ...The rapid evolution of flexible electronic devices promises to revolutionize numerous fields by expanding the applications of smart devices.Nevertheless,despite this vast potential,the reliability of these innovative devices currently falls short,especially in light of demanding operation environment and the intrinsic challenges associated with their fabrication techniques.The heterogeneity in these processes and environments gives rise to unique failure modes throughout the devices'lifespan.To significantly enhance the reliability of these devices and assure long-term performance,it is paramount to comprehend the underpinning failure mechanisms thoroughly,thereby,enabling,optimal design solutions.A myriad of investigative efforts have been dedicated to unravel these failure mechanisms,utilizing a spectrum of tools from analytical models,numerical methods,to advanced characterization methods.This review delves into the root causes of device failure,scrutinizing both the fabrication process and the operation environment.Next,We subsequently address the failure mechanisms across four commonly observed modes:strength failure,fatigue failure,interfacial failure,and electrical failure,followed by an overview of targeted characterization methods associated with each mechanism.Concluding with an outlook,we spotlight ongoing challenges and promising directions for future research in our pursuit of highly resilient flexible electronic devices.展开更多
In this paper we reported the preparation and extensive characterization of La9.83–x Sr x Si6O26+δ(0≤x≤0.50) precursors, intermediate and final products. The sintering reactions, the phase formation, the struct...In this paper we reported the preparation and extensive characterization of La9.83–x Sr x Si6O26+δ(0≤x≤0.50) precursors, intermediate and final products. The sintering reactions, the phase formation, the structure as well as the powders' morphology were studied by means of thermogravimetric analysis, X-ray diffraction(XRD), Fourier-transform infrared spectroscopy(FTIR) and scanning electron microscopy(SEM). Moreover, the effect of stoichiometry on precursor's structure and morphology as well as on intermediate and final products was reported. As was concluded pure La9.83Si6O26+δ, La9.38Sr0.45Si6O26+δ and La9.33Sr0.50Si6O26+δ could be prepared after sintering at 1400 °C for 20 h while La9.68Sr0.15Si6O26+δ and La9.53Sr0.30Si6O26+δ compounds contained minor traces(〈3.5%) of La2Si2O7 secondary phase. Concerning the synthesis, there have been no previous reports on the preparation of pure La9.83Si6O26+δ, La9.38Sr0.45Si6O26+δ and La9.33Sr0.50Si6O26+δ compounds. The final powders consisted of spherical particles and an increase of Sr content seemed to inhibit sintering phenomena. The existence of interstitial oxygen at intermediate crystallographic positions of apatite structure had great effect on Si O4 sub-structure distortion. The increase of Sr content led to a major reduction of interstitial oxygen quantity and the refutation of silicon tetrahedron distortion.展开更多
A series of novel ester-capped carbosilane dendrimers(G0-COOCH3–G2-COOCH3) were designed and successfully synthesized via a hybrid divergent–convergent method through a facile hydrosilylation reaction. The structu...A series of novel ester-capped carbosilane dendrimers(G0-COOCH3–G2-COOCH3) were designed and successfully synthesized via a hybrid divergent–convergent method through a facile hydrosilylation reaction. The structures of these dendrimers were confirmed by FTIR,1H NMR, and HRMS analyses.展开更多
基金supported by the National Natural Science Foundation of China(No.51966015).
文摘The development of azobenzene photoisomerization materials marks a pivotal advancement in solar-thermal conversion technologies.Their properties and performance,explored through comprehensive characterization,are vital for further progress.Despite extensive research in this area,a detailed summary of characterization methods for azobenzene materials remains largely unexplored.This review addresses this gap by detailing structural and performance characterization techniques.It provides an in-depth overview of various experimental methods,highlighting their objectives,operational mechanics,and practical applications.This detailed review sheds light on the complex relationship between the materials'structure and their performance.Moreover,the review presents a critical analysis of these methods,assessing their strengths and limitations.By doing so,it highlights the revolutionary potential of azobenzene materials in the realm of solar energy conversion and underscores their significance in fostering sustainable energy solutions.
基金financially supported by the National Key R&D Program of China(No.2022YFC2906100).
文摘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.
基金This work was supported by National Science Foundation of China(51602191,51602190)the Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning.
文摘The development of high-performance lithium ion batteries requires the discovery of new materials and the optimization of key components.By contrast with traditional one-by-one method,high-throughput method can synthesize and characterize a large number of compositionally varying samples,which is able to accelerate the pace of discovery,development and optimization process of materials.Because of rapid progress in thin film and automatic control technologies,thousands of compounds with different compositions could be synthesized rapidly right now,even in a single experiment.However,the lack of rapid or combinatorial characterization technologies to match with high-throughput synthesis methods,limit the application of high-throughput technology.Here,we review a series of representative highthroughput characterization methods used in lithium batteries,including high-throughput structural and electrochemical characterization methods and rapid measuring technologies based on synchrotron light sources.
基金The authors acknowledge the financial support from the National Natural Science Foundation of China(51474164,U1760101 and 51704216).
文摘At present,blast furnace ironmaking is still the main process for producing molten iron,and sinters are the main raw material for blast furnace ironmaking.A sinter with good metallurgical performance can not only ensure smooth operation of the blast furnace but also reduce the blast furnace fuel ratio and increase the molten iron production.Structure is the most important factor affecting the metallurgical properties of the sinter.Thus,the research progress of sinter pore and mineral phase structures was reviewed and the mechanism by which they influence sinter properties was expounded.Multiscale characterization methods for the sinter and their advantages and disadvantages were introduced,and the future research direction of sinter was discussed.
基金supported by the Key National Research and Development Programs(No.2016YFC1000900)
文摘Ethinyl estradiol(EE) as a contraceptive,(17α)-19-nopregna-1,3,5-(10)-trien-20-yne-3,17-diol(formula: C(20)H(24)O2, molecular weight: 296.4, CAS number: 57-63-6), is known to have different pseudo-polymorphic forms. Some EE polymorphs have been synthesized by means of physical or chemical methods, characterized by X-ray powder diffraction(XRPD), thermogravimetric(TG), differential scanning calorimetry(DSC) and IR spectra. Dissolution profile was tested by high performance liquid chromatography(HPLC). Meanwhile, the crystal structure of the new EE solvate(formamide) was characterized by single-crystal X-ray structure analysis(SXRD). The results confirmed that EE existed polymorphism. Five crystal forms of EE were presented and two of them were reported firstly. Furthermore, five polymorphs' dissolution curves were drawn and they could be identified by several analysis methods. Our study on polymorphs of EE could provide a variety of crystal material composition, preparation methods and solubility.
基金Tsupported by the Science and Technology Development Project of Henan Province(grant no.202300410048)the Intelligence Introduction Plan of Henan Province in 2021(CXJD2021008)+3 种基金the Postdoctoral Fund of China(grant no.FJ3050A0670111)the Henan University Fundthe Canada Research Chairs Supplement FundNew Frontiers in Research Fund(NFRF)。
文摘A photovoltaic technology historically goes through two major steps to evolve into a mature technology. The first step involves advances in materials and is usually accompanied by the rapid improvement of power conversion efficiency. The second step focuses on interfaces and is usually accompanied by significant stability improvement. As an emerging generation of photovoltaic technology, perovskite solar cells are transitioning to the second step of their development when a significant focus shifts toward interface studies and engineering. While various interface engineering strategies have been developed, interfacial characterization is crucial to show the effectiveness of interfacial modification. Here, we review the characterization techniques that have been utilized in studying interface properties in perovskite solar cells. We first summarize the main roles of interfaces in perovskite solar cells, and then we discuss some typical characterization methodologies for morphological, optical,and electrical studies of interfaces. Successful experiences and existing problems are analyzed when discussing some commonly used methods. We then analyze the challenges and provide an outlook for further development of interfacial characterizations. This review aims to evoke strengthened research devotion on novel and persuasive interfacial engineering.
文摘A simple creep testing method is presented which involves using coiled specimens. With this method, a single experiment can give all the data required for a plot of strain rate versus stress. The value of the stress-expo-nent of room temperature steady-state creep a Pb-61. 5wt %Sn solder was measured in this way to be 1. 06,aselected from a diffusion creep mechanism.
基金Projects(50471102,50671089) supported by the National Natural Science Foundation of China
文摘In order to establish the quantitative relationship between equivalent strain and the performance index of the deformed material within the range of certain passes for equal channel angular processing (ECAP), a new approach to characterize the equivalent strain was proposed. The results show that there exists better accordance between mechanical property (such as hardness or strength) and equivalent strain after rolling and ECAP in a certain range of deformation amount, and Gauss equation can be satisfied among the equivalent strain and the mechanical properties for ECAP. Through regression analysis on the data of hardness and strength after the deformation, a more generalized expression of equivalent strain for ECAP is proposed as:ε=k0exp[-(k1M-k2)^2], where M is the strength or hardness of the material, k1 is the modified coefficient (k1∈ (0, 1)), ko and k2 are two parameters dependent on the critical strain and mechanical property that reaches saturation state for the material, respectively. In this expression the equivalent strain for ECAP is characterized novelly through the mechanical parameter relating to material property rather than the classical geometry equation.
文摘Validating a method of analysis goes through different steps, which aims at testing the normality of measurements distribution, estimating the uncertainty of the components of a measurement (i.e., accuracy and correctness), and finally, define the control tests of non degradation of the method performances. This paper outlines the steps for validating a biological method of analysis. It involves the construction of an experimental design, a statistical model, and the preparation of an interne laboratory reference material (pilot vaccine). The latter is used to study the impact of deviation and variation factors, in order to, optimize the analytical method, to evaluate the bias (random error), and to calculate the uncertainty of measurement, and make the control charts. This method is applied in the titration of live viral vaccines of Gumboro disease on chicken's embryos fibroblasts. The experimental results show that potential influence factors related to the titration method had no significant influence on the obtained results. Taking into account these results, an operating mode has been elaborated. The finalized method proved to be faithful to standard deviation of repeatability and reproducibility of 0.21 and 0.22, respectively, with a confidence level of 95%. The calculated uncertainty of measurement is equal to 0.2, which represents the average error level of a titer. A homogeneous stock of interne laboratory reference vaccine (MRIL), with an average titer of 5.9 log DIT 50, was produced and the control chart set in away to provide the laboratory with an important tool of control and monitoring of the viral titers evolution in time, as well as, the mastery of the validated titration method performances.
文摘The compounds of iron substituted yttrium oxide systems have been prepared for the importance in the field of magneto electric materials.The polycrystalline samples of Y2–xFexO3–y(x=0.1,0.2) were prepared by solid-state reaction method.The single-phase formation of these compounds was confirmed by X-ray diffraction studies.It was found that the samples crystallized in tetragonal phase and the lattice parameters were calculated as a=1.0559(7) nm,c=1.0832(9) nm for Y1.9Fe0.1O3–y and a=1.0545(6) nm,c=1.0841(8)...
基金supported by the National Natural Science Foundation of China(51804290,22075025,21975026)the Beijing Natural Science Foundation(L182023)+1 种基金the Science and Technology Program of Guangdong Province(Grant No.2020B0909030004)the Beijing Institute of Technology Research Fund Program for Young Scholars(2019CX04092)。
文摘With the advancement of secondary batteries,interfacial properties of electrode materials have been recognized as essential factors to their electrochemical performance.However,the majority of investigations are devoted into advanced electrode materials synthesis,while there is insufficient attention paid to regulate their interfaces.In this regard,the solid electrolyte interphase(SEI)at anode part has been studied for 40 years,already achieving remarkable outcomes on improving the stability of anode candidates.Unfortunately,the study on the cathode electrolyte interfaces(CEI)remains in infancy,which constitutes a potential restriction to the capacity contribution,stability and safety of cathodes.In fact,the native CEI generally possesses unfavorable characteristics against structural and compositional stability that requires demanding optimization strategies.Meanwhile,an in-depth understanding of the CEI is of great significance to guide the optimization principles in terms of composition,structure,growth mechanism,and electrochemical properties.In this literature,recent progress and advances of the CEI characterization methods and optimization protocols are summarized,and meanwhile the mutually-reinforced mechanisms between detection and modification are explained.The criteria and the potential development of the CEI characterization are proposed with insights of novel optimization directions.
基金supported by the National Natural Science Foundation of China(51072170,21321062)the National Basic Research Program of China(2012CB932900)
文摘Dye-sensitized solar cell (DSSC) is one of the most rapidly developed solar cells in the past 20 years. Many characterization methods have been employed for further understanding the operational details of the photo- electric conversion in DSSC as well as the evaluation of cell performance. Electrochemical methods have become pow- erful tools for studying the charge transfer and interfacial process. In this review, we introduce and explain the various electrochemical methods used to characterize and analyze DSSC, including current-voltage (I-V) scan measurement, cyclic voltammetry, electrochemical impedance spec- troscopy, intensity-modulated photocurrent spectroscopy, and intensity-modulated photovoltage spectroscopy. In ad- dition, some applications were provided as samples to elucidate electron transfer kinetics, energy levels and electrocatalytic activity of the materials used in DSSC.
文摘Multiuser online system is useful, but the administrator must be nervous at security problem. To solve this problem, the authors propose applying signature verification to multiuser online system. At the authors' research, they attempt adding signature verification function based on DP (Dynamic Programming) matching to existing multiuser online kanji learning system. In this paper, the authors propose the construction of the advance system and methods of signature verification, and evaluate performance of those signature verification methods that difference is combination of using features. From signature verification's experimental results, the authors adopted to use writing velocity and writing speed differential as using feature to verify the writer for the system. By using signature database which is construct with 20 genuine signatures and 20 forged signatures with 40 writers and written mostly by English or Chinese literal, experimental results of signature verification records 12.71% as maximum EER (Equal Error Rate), 6.00% as minimum EER, and 8.22% as average EER. From mentioned above, the authors realized to advance the reliability and usefulness of the multiuser online kanji learning system.
基金research affairs of Islamic Azad University,Najafabad Branch,for supporting this research.
文摘Hydroxyapatite-magnesium titanate composite nanopowders have been developed using a mechanothermal process.Thermal treatment of the milled powders at 700℃resulted in the formation of HAp/MgTiO_(3)-MgO nanocomposite.X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),and energy dispersive X-ray spectroscopy(EDX)techniques were utilized to characterize the synthesized powders.The results revealed that the dominant phases after mechanical activation were hydroxyapatite,anatase(TiO_(2))and periclase(MgO);while after thermal annealing process at 700℃,hydroxyapatite along with geikielite(MgTiO_(3))and periclase(MgO)were the major phases.Based on the XRD analysis,the evaluation of structural features of the samples indicated that the average crystallite sizes of hydroxyapatite after 10 h of milling and subsequent thermal treatment at 700℃were about 21 nm and 34 nm,respectively.Microscopic observations illustrated that the synthesized powders contained large agglomerates which consisted of significantly finer particles with spheroidal morphology.It is concluded that the mechanothermal method can be used to produce hydroxyapatite-based nanocomposite with appropriate structural and morphological features.
基金supported by the Natural Science Foundation of China(No.21174114)the Ministry of Education Plan for Yangtze River Scholar and Innovation Team Development(No.IRT1177)+2 种基金Scientific and Technical Plan Project of Gansu Province(No. 1204GKCA006)the Natural Science Foundation of Gansu Province (No.1010RJZA024)Scientific and Technical Innovation Project of Northwest Normal University(No.nwnu-kjcxgc-03-63)
文摘ZnO/graphene oxide(ZnO/GO) composite material,in which ZnO nanoparticles were densely coated on the GO nanosheets,was successfully prepared by an improved two-step method and characterized by IR, XRD,TEM,and UV-vis techniques.The improved photocatalytic property of the ZnO/GO composite material,evaluated by the photocatalytic degradation of methyl orange(MO) under UV irradiation,is ascribed to the intimate contact between ZnO and GO,the enhanced adsorption of MO,the quick electron transfer from excited ZnO particles to GO sheets and the activation of MO molecules viaπ-πinteraction between MO and GO.
基金the National Natural Science Foundation of China (No. 69631020) and theOffice of Naval Research of America (00014-93-1-0340).
文摘A low-frequency multi-mode ultrasonic Lamb wave method suitable for character- izing the thickness, the density and the elastic constants of the ultra-thin transversely isotropic laminate composite is presented. The 'ultra-thin' here means that the thickness of the plate is much less than the wavelength of the ultrasonic wave so that the echoes from the front and back faces of the plate can't be separated in the time domain. The dispersion equations for the low frequency ultrasonic Lamb waves with the propagation directions parallel and vertical to the fiber direction are derived. In conjunction with the least square algorithm method, the secant algorithm is used to estimate the parameters of the ultra-thin fiber-reinforced composite layer. The evaluation errors and the sensitivity of the method to different paramters of the thin composite are analyzed. The technique has been used to characterize the ultra-thin grass fiber reinforced PES composite with thickness down to ten percents of the ultrasonic wavelength. It is observed that the agreement between the nominal and the estimation values is reasonably good.
文摘Automatic identification of characters marked on billets is very important for steelworks to achieve manu- facturing and logistics informatization management. Due to the presence of adhesions, fractures, blurs, and other problems in characters painted on billets, character recognition accuracy with machine vision is relatively low, and hardly meets practical application requirements. To make the character recognition results more reliable and accu- rate, an identification results classification and post-pro- cessing method has been proposed in this paper. By analyzing issues in the image segmentation and recognition stage, the recognition result classification model, based on character encoding rules and recognition confidence, is built, and the character recognition results can be classified as correct, suspect, or wrong. In the post-processing stage, a human-machine-cooperation mechanism with a post- processing interface is designed to eliminate error infor- mation in suspect and wrong types. The system was developed and experiments conducted with images acquired in an iron and steel factory. The results show the character recognition accuracy to be approximately 89% using the character recognizer. However, this result cannot be directly applied in information management systems. With the proposed post-processing method, a human worker will query the suspect and wrong results classified by the system, determine whether the result is correct or wrong, and then, correct the wrong result through the post-processing interface. Using this method, the character recognition accuracy ultimately improves to 99.4%. Thus, the results will be more reliable applied in a practical system.
基金support by the National Natural Science Foundation of China(NSFC)[Grant No.11972325,12272342,12202398]the Natural Science Foundation of Zhejiang Province(LGF20A020001).
文摘The rapid evolution of flexible electronic devices promises to revolutionize numerous fields by expanding the applications of smart devices.Nevertheless,despite this vast potential,the reliability of these innovative devices currently falls short,especially in light of demanding operation environment and the intrinsic challenges associated with their fabrication techniques.The heterogeneity in these processes and environments gives rise to unique failure modes throughout the devices'lifespan.To significantly enhance the reliability of these devices and assure long-term performance,it is paramount to comprehend the underpinning failure mechanisms thoroughly,thereby,enabling,optimal design solutions.A myriad of investigative efforts have been dedicated to unravel these failure mechanisms,utilizing a spectrum of tools from analytical models,numerical methods,to advanced characterization methods.This review delves into the root causes of device failure,scrutinizing both the fabrication process and the operation environment.Next,We subsequently address the failure mechanisms across four commonly observed modes:strength failure,fatigue failure,interfacial failure,and electrical failure,followed by an overview of targeted characterization methods associated with each mechanism.Concluding with an outlook,we spotlight ongoing challenges and promising directions for future research in our pursuit of highly resilient flexible electronic devices.
基金funded by the Research Committee of National Technical University of Athens
文摘In this paper we reported the preparation and extensive characterization of La9.83–x Sr x Si6O26+δ(0≤x≤0.50) precursors, intermediate and final products. The sintering reactions, the phase formation, the structure as well as the powders' morphology were studied by means of thermogravimetric analysis, X-ray diffraction(XRD), Fourier-transform infrared spectroscopy(FTIR) and scanning electron microscopy(SEM). Moreover, the effect of stoichiometry on precursor's structure and morphology as well as on intermediate and final products was reported. As was concluded pure La9.83Si6O26+δ, La9.38Sr0.45Si6O26+δ and La9.33Sr0.50Si6O26+δ could be prepared after sintering at 1400 °C for 20 h while La9.68Sr0.15Si6O26+δ and La9.53Sr0.30Si6O26+δ compounds contained minor traces(〈3.5%) of La2Si2O7 secondary phase. Concerning the synthesis, there have been no previous reports on the preparation of pure La9.83Si6O26+δ, La9.38Sr0.45Si6O26+δ and La9.33Sr0.50Si6O26+δ compounds. The final powders consisted of spherical particles and an increase of Sr content seemed to inhibit sintering phenomena. The existence of interstitial oxygen at intermediate crystallographic positions of apatite structure had great effect on Si O4 sub-structure distortion. The increase of Sr content led to a major reduction of interstitial oxygen quantity and the refutation of silicon tetrahedron distortion.
基金support by the National Natural Science Foundation of China(No.21307053)China Postdoctoral Science Foundation Funded Project(No.2013M541911)+1 种基金Promotive Research Fund for Excellent Young and Middle-Aged Scientists of Shandong Province(No.BS2013CL044)Natural Science Foundation of Ludong University(No.LY2011004)
文摘A series of novel ester-capped carbosilane dendrimers(G0-COOCH3–G2-COOCH3) were designed and successfully synthesized via a hybrid divergent–convergent method through a facile hydrosilylation reaction. The structures of these dendrimers were confirmed by FTIR,1H NMR, and HRMS analyses.