Configuration Transformation Research Articles

La(Fe,Si/Al)13-based materials with exceptional magnetic functionalities: a review

The field of magnetic functional materials continues to garner significant attention due to its research and diverse applications, such as magnetic storage and spintronics. Among these, La(Fe,Si/Al)13-based materials exhibit abundant magnetic properties and emerge as highly captivating subjects with immense potential. This review provides an overview of the diverse magnetic structures and itinerant electron metamagnetic transition observed in La(Fe,Si/Al)13-based materials. The transformation of different magnetic configurations elicits the phenomena such as negative thermal expansion, magnetostriction, magnetocaloric effect, and barocaloric effect. In addition, the pivotal role of spin and lattice coupling in these phenomena is revealed. The magnetic functionalities of La(Fe,Si/Al)13-based materials can be controlled through adjustments of magnetic exchange interactions. Key methods, including chemical substitution, external field application, and interstitial atom insertion, enable precise modulation of these functionalities. This review not only provides valuable insights into the design and development of magnetic functional materials but also offers significant contributions to our understanding of the underlying mechanisms governing their magnetic behaviors.

Atomistic Simulation of the Interaction between the Σ9[110](221) Shear-Coupled Grain Boundary Motion and the Cu-rich Precipitates in α-Iron

Shear-coupled grain boundary motion (SCGBM) is an important and efficacious plasticity mechanism in the deformation of metals. In this work, a molecular dynamic (MD) simulation of the interaction between the SCGBM of Σ9[110](221) GB and Cu-rich precipitates in α-iron was carried out. The effects of the size, the temperature, and the composition of the Cu precipitates were also studied. It was found that the precipitates inhibited the GB motion significantly, and the configuration transformation from spheroid to ellipsoid was also investigated in the simulation results. The critical stress of the interaction increased with the size of the precipitates. At higher temperatures, the GB sliding event increased the critical stress of the GB motion, which was higher than that of the interaction, inducing no stress-rise stage in the stress–time curve. The critical stress of the CuNi precipitates on the SCGBM was higher than that of the pure Cu precipitates with the same size, which was one of the reasons for the outstanding strength of the high-strength low-alloy (HSLA) steels compared with the traditional Cu-containing steels.

New insights into the effect of pyrolysis temperature on the spectroscopy properties of dissolved organic matter in manure-based biochar.

Dissolved organic matter (DOM) derived from biochar takes a crucial role in transport and bioavailability toward contaminants; hence, it is undeniable that a thorough analysis of its properties is important. So far, the effect of pyrolysis temperature on the functional groups, components, and evolutionary sequence of manure-based biochar DOM has not been adequately investigated. Here, DOM was released from two typical livestock manures (cow and pig) at five pyrolysis temperatures (300 ~ 700°C), and it was explored in depth with the aid of moving window 2D correlation spectroscopy (MW-2D-COS) and heterogeneous 2D correlation spectroscopy (hetero-2D-COS). The results demonstrated that the concentration, aromaticity, and hydrophobicity of DOM were greater at high temperatures, and more DOM was liberated from cow manure-based biochar at identical temperature. Protein-like compounds dominated at high temperatures. The pyrolysis temperatures of final configuration transformation points of the fulvic acid-like component and the aromatic ring C=C in DOM were 400°C and 500°C, respectively. Moreover, Fourier transform infrared spectroscopy combined with two-dimensional correlation analysis indicated that the functional group evolution of DOM depends on the pyrolysis temperature and feedstock type. The study provides a new perspective on manure management and environmental applications of biochar.

Regulation of ovalbumin allergenicity and structure-activity relationship analysis based on pulsed electric field technology

The study focused on the regulation of ovalbumin (OVA) allergenicity using pulsed electric field (PEF) technology and examined the structure-activity link. Following PEF treatment, the ability of OVA to bind to IgE and IgG1 at 6 kHz was inhibited by 30.41 %. According to the microstructure, PEF caused cracks on the OVA surface. Spectral analysis revealed a blue shift in the amide I band and a decrease in α-helix and β-sheet content indicating that the structure of OVA was unfolded. The disulfide bond conformation was transformed and the structure tended to be disordered. The increased fluorescence intensity indicated that tryptophan and tyrosine were exposed which led an increase in hydrophobicity. In addition, the results of molecular dynamics (MD) simulations confirmed that the stability of OVA was reduced after PEF, which was related to the reduction of hydrogen bonding and the sharp fluctuation of aspartic acid. Therefore, PEF treatment induced the exposure of hydrophobic amino acids and the transformation of disulfide bond configuration which in turn masked or destroyed allergenic epitopes, and ultimately inhibited OVA allergenicity. This study provided insightful information for the production of hypoallergenic eggs and promoted the use of PEF techniques in the food field.

Thermal and Vapor Induced Triple‐Mode Luminescent Switch of Manganese (II) Halides Hybrid

AbstractIt is imminent to develop phosphors with multiple stimuli responses due to the increasing demand on anti‐counterfeiting and information encryption technologies. Here, a zero dimensional (0D) organic–inorganic hybrid (DPPE)2MnBr4·H2O (DPPE = 4,4‐Difluoropiperidine, 1), which emits green light and exhibits reversible thermo‐ and vapor‐luminescence responses to heat and organic solvents is reported. Specifically, when heated above 100 °C for 30 s, hybrid 1 transforms into yellow‐emitting hybrid 2. Upon exposure to dichloromethane (DCM), it transforms into a red‐emitting hybrid 3. Experimental analysis reveals that Mn2+‐Mn2+ magnetic coupling interactions and coordination configuration transformation are responsible for the obvious switching of photoluminescence. Owing to its extraordinary triple‐mode switching characteristics, enabling luminescence‐adjustable transformations such as green to yellow, green to red, and yellow to red emission, this metal‐halide hybrid is promising for the application in anti‐counterfeiting and information encryption.

The Affective Configuration of the Public Problem of Depopulation: From Resignation to Obstinance

Participation in public problems involves diverse strategies, including the challenging and transformation of hegemonic affective configurations. By exposing and disrupting the established emotional norms, actors gain affective agency, enabling resistance against the prevailing status quo and facilitating active engagement in democratic deliberation. To explore this idea, we present a sociocultural analysis of the Empty Spain Revolt (Revuelta de la España Vaciada) as a compelling case study. Employing semiotic-enunciational discourse analysis, we focus on the affective-emotional dimension, utilizing the movement’s Manifesto and photographs of banners from the March 31, 2019, demonstration in Madrid as our primary sources. Our research reveals the emergence of affective agency through three gestures: 1) Indignation as a Catalyst: Indignation serves as a driving emotion, stemming from frustration due to perceived neglect. This emotion fosters the assignment of responsibility to political parties and fuels demands for immediate action. 2) Pride and Urban-Rural Dynamics: The appeal to urban subject emphasizes the interdependence between urban and rural areas, advocating for justice, equality, and rural dignity. 3) From Resignation to Obstinance: The transition from a resigned figure to an obstinate figure shifts the enunciative agency. The resolute voices of the obstinate subject sustain a collective identity and enable a politically active subject. Our analysis underscores the pivotal role of affects and emotions in shaping public problems and in the articulation of actor. The process of dismantling existing affective configurations and presenting alternative ones not only influences encyclopedias and imaginaries but also impacts collective agency and power structures. This study offers insights into the intricate relationship among affect, discourse, and sociopolitical change.

Vibrational spectroscopy of dispersed ReVIIOx sites supported on monoclinic zirconia.

In situ Raman and FTIR spectra complemented by in situ Raman/18O isotope labelling are exploited for deciphering the structural properties and configurations of the (ReOx)n phase dispersed on monoclinic ZrO2 at temperatures of 120-400 °C under oxidative dehydration conditions and coverages in the range of 0.71-3.7 Re nm-2. The dispersed (ReOx)n phase is heterogeneous, consisting of three distinct structural units: (a) Species-I with mono-oxo termination ORe(-O-Zr)m (ReO mode at 993-1005 cm-1); (b) Species-IIa with di-oxo termination (O)2Re(-O-Zr)m-1 (symmetric stretching mode at 987-998 cm-1); and (c) Species-IIb with di-oxo termination (O)2Re(-O-Zr)u (symmetric stretching mode at 982-991 cm-1); all terminal stretching modes undergo blue shifts with increasing coverage. With increasing temperature, a reversible temperature-dependent Species-IIa ↔ Species-I transformation is evidenced. At low coverages, below 1 Re nm-2, isolated species prevail; at 400 °C the mono-oxo ORe(-O-Zr)m Species-I is the majority species, the di-oxo Species-IIa occurs in significant proportion and di-oxo Species-IIb is in the minority. At coverage ≥1.3 Re nm-2, at 400 °C the di-oxo Species-IIa prevails clearly over mono-oxo Species-I. Below 80 °C and at a low coverage of 0.71 Re nm-2, the occurrence of a fourth structural unit, Species-III taking on a tri-oxo configuration (symmetric stretching mode at 974 cm-1) is evidenced. All temperature-dependent structural and configurational transformations are fully reversible and interpreted by mechanisms at the molecular level.

Wartości niematerialne i turystyka przestrzeni publicznych w starożytnym centrum Neapolu (Włochy)

The identity of the ancient city centre of Naples has been historically founded on the co-existence of tangible and intangible values underpinning a compact fabric of centuries-old architectural and urban stratifications. Their lasting character and presence in public spaces contributes to the image of Naples as an authentic and multi-layered city, recognized as Historic Urban Landscape and listed as a World Heritage Site twenty-eight years later. At the same time, preservation of these values poses a challenge with regard to the change of roles in some public spaces due to material, economic and social pressure, particularly touristification. This cyclical process determined by physical transformations of the urban configuration and new functional characterization of “overtouristic” areas is especially affecting public spaces located along the main tourist routes in the ancient centre, for example the churchyard of Santa Chiara. The article aims to reflect on the prospects of these areas, examining the role played by touristification in the conservation of their identity as crucial in the management of historic urban preservation. This is supplemented with more general reflections on significant spaces such as churchyards and gardens, which are turned into public areas, shaping both cities and their citizens, with the aim to define the right balance between the reasons behind development and the conservation of heritage and authenticity.

Robust anti-perturbation safety control of multi-heterogeneous unmanned vessels

The identical nature of unmanned vessels in a homogeneous formation imposes limitations on their adaptability to diverse task demands in complex environmental conditions or constantly evolving task requirements, hindering their ability to achieve optimal performance. This paper presents the heterogeneous formation comprising fully actuated and underactuated vessels to overcome these limitations. Firstly, an affine transformation is employed to implement arbitrary configuration transformations within the formation system. Secondly, a composite learning formation controller is proposed for the underactuated vessels acting as the leaders to track the arbitrary formation transformation. Thirdly, considering that certain followers have access to the state information of the leaders, a new virtual leader–follower structure is constructed to achieve formation maneuver control by designing distributed estimators to estimate the state information of the virtual leader. Finally, simulation results validate the proposed control law’s effectiveness.

THE EFFECT OF THE TRANSFORMATION PROCESS: ORGANIZATIONAL CHANGES AND MATHEMATICAL STATISTICS

Organizational changes for the purpose of enterprise development, as a topic of scientific research, are especially relevant for Ukraine now, when organizations need systematic and continuous development, which in most cases depends on how the process of transforming the structural configuration will take place in the process of implementing the enterprise's strategy, if it is the transformation of the configuration necessary due to a change in the level of influence of the main characteristics of the external environment. In turn, the fact of achieving the goal of transformation cannot be considered without determining the effect of this process.
 The need for theoretical substantiation of the transformation’s effect of the organization as an economic category arose long before the appearance of most modern methods of building organizational structures and methods of mathematical statistics. At the current level of understanding the transformation process, new models of organizational construction are important. Therefore, this article considers the application of mathematical statistics methods in the context of determining the effect of enterprise transformation in case of organizational changes.
 The work proposes to consider the possibility of determining the effect of the transformation process by mathematical modelling for enterprises occupying a monopoly position on the market of goods and services in the case of fixing the sale price of products by state regulators and for organizations belonging to the market structures of imperfect and perfect competition, unregulated monopoly and oligopolies.
 It is proved that the expansion of the break-even zone of the enterprise after the transformation of the organizational form configuration, which is determined by the ratio of the functional dependencies of the cost and income parts over time, can be considered as an indicator of the effect on the transformation process of the enterprise.
 It is the indicator of the transformation process effect, which is characterized by a change towards the expansion of the break-even zone, that should be used in various cases of transformational changes, in particular, in case of existing restrictions on the total volume of sales of the company's products while optimizing the growth of production costs.

Brønsted ionic liquids as catalysts for synthesis of 2-pyrazoline derivatives from ketazines: A combined experimental and theoretical approach

Brønsted ionic liquids (BILs) were designed and applied to catalyze intramolecular cyclization of ketazines to 2-pyrazoline derivatives. Under the optimal conditions as 90 °C, 15 mol% [PsBim][CF3SO3] dosage and 4 h, the conversion rate and selectivity of the reaction are up to 98 % and 99 % respectively. Through the substrate screening, it shows that the steric hindrance of the R group in ketazines is a big factor of cyclization activities, following the order of methyl (98 %) > ethyl (93 %) > n-propyl (87 %) > n‑butyl (81 %) > isopropyl (52 %) > isobutyl (46 %)> neobutyl (13 %). Moreover, the results of the density functional theory (DFT) calculations indicate that the cations and anions of BIL can synergistically participate in the ketazines configuration transformation step so as to significantly reduce the Gibbs free barrier energy from 30.65 to 20.12 kcal/mol, thereby promoting the cyclization reaction to synthesize 2-pyrazoline derivatives.

Reblooming of the cis-Bis(2-phenylpyridine) Platinum(II) Complex: Synthesis Updating, Aggregation-Induced Emission, Electroluminescence, and Cell Imaging.

Studies on the syntheses, photophysical properties, and applications of cis-bis(2-phenylpyridine) platinum(II) complex (Pt(ppy)2) family are of great importance, but very limited progress has been achieved to date. Herein, a one-pot method was established for the syntheses of Pt(ppy)2-type complexes Pt-ppy and Pt-tBu. These two compounds were nonemissive in dilute solutions. However, they produced intense red and deep-red phosphorescence in the aggregation and film states, with lifetimes and quantum yields up to 1.92 μs and 70%, respectively, exhibiting unique aggregation-induced emission (AIE) characteristics. According to the experimental and theoretical studies, molecular configuration transformation (MCT) in the excited state may occur because of the d-d transition from the Pt center, causing nonradiative transitions in the solution. Nevertheless, the MCT would be largely restricted by the intermolecular interactions or rigid matrix, thereby enabling efficient phosphorescence in the aggregation state and in the PMMA films. Consequently, the AIE characteristics of Pt-ppy and Pt-tBu probably result from the restriction of molecular configuration transformation (RMCT). Due to the π-π and/or weak Pt-Pt interactions and the concentration-dependent emission characteristics, they emit deep-red and NIR emissions generated by excimer and/or MMLCT emitting species. Inspired by their AIE features, electroluminescence and cell imaging applications are explored. To the best of our knowledge, this is the first comprehensive study on the synthesis optimization, photophysical properties, AIE characteristics, and applications of the Pt(ppy)2-type complexes, which may rebloom the research studies on this type of Pt(II) complex family and provide valuable insights on the development of phosphorescent AIE metal-organic complexes.

Modeling and numerical simulation of thermo-electro-mechanical coupling behaviors of liquid crystal elastomers

Liquid crystal elastomer (LCE), as a newly emerging soft material, has been extensively explored to construct diverse structures for a wide range of applications. Many unique yet complex properties of LCEs originate from the tight coupling between the alignment of liquid crystal mesogens and the deformation of polymer network. It makes the modeling and simulation of the deformation of LCEs caused by the actions of multiple external stimuli very challenging. In this work, we formulate a theoretical framework to model the intricate behaviors of LCEs with thermo-electro-mechanical coupling and derive analytical solutions for homogeneous deformation. To implement the model in finite element simulation, a numerical approach that employs a quasi-convexified free energy function and achieves a key transformation of reference configuration is proposed. The numerical approach is further developed into a user subroutine for the commercial software ABAQUS. Various simulations are conducted by using it to validate the effectiveness of the model and numerical approach, as well as to demonstrate their potential applications. We hope the current work, particularly the developed program, provides a useful tool for various researchers to study the complex phenomena of LCEs.

Gait and simulation analysis of quadruped crawling robot based on metamorphic structure

PurposeThis study aims to present a type of metamorphic mechanism-based quadruped crawling robot. The trunk design of the robot has a metamorphic mechanism, which endows it with excellent crawling capability and adaptability in challenging environments.Design/methodology/approachThe robot consists of a metamorphic trunk and four series-connected three-joint legs. First, the walking and steering strategy is planned through the stability and mechanics analysis. Then, the walking and steering performance is examined using virtual prototype technology, as well as the efficacy of the walking and turning strategy.FindingsThe metamorphic quadruped crawling robot has wider application due to its variable trunk configuration and excellent leg motion space. The robot can move in two modes (constant trunk and trunk configuration transformation, respectively, while walking and rotating), which exhibits outstanding stability and adaptability in the examination and verification of prototypes.Originality/valueThe design can enhance the capacity of the quadruped crawling robot to move across a complex environment. The virtual prototype technology verifies that the proposed walking and steering strategy has good maneuverability and stability, which considerably expands the application opportunity in the fields of complicated scene identification and investigation.

Phase transition behavior and mesophase aging phenomenon during liquid-state carbonization of FCC decant oil

The FCC decant oil (FCC-DO), primarily comprising 2- to 5-ring aromatic hydrocarbons with short alkyl side-chains, is widely acknowledged as the optimal precursor for the production of spinnable mesophase pitch, thus achieving its high-value utilization. The preparation of spinnable mesophase pitch from FCC-DO faces the challenge associated with achieving both high mesophase content and low softening point. To address this challenge, the phase separation behavior of the isotropic matrix and the aging phenomenon of coexisting anisotropic phases are examined using high-temperature centrifugation and advanced analytical techniques. The phase transition behavior of isotropic matrix can be described by a multi-stage continuous self-assembly induced by polymerized reactions. And this dynamic assembly process is tightly related to “steric hinderance effect” and “solvent dispersion effect”, which are mainly affected by the configuration and size distribution of formed mesogens respectively. Meanwhile, the formed anisotropic phase gradually undergoes two-staged time-dependent aging behavior, leading to poor compatibility of sub-fractions and then deterioration of melt fluidity. The initial aging of the mesophase is characterized by an almost unchanged molecular weight distribution, but a transformation of molecular configuration from a semi-rigid skeleton to a rigid one. This transformation is caused by intramolecular condensation resulting from the removal of the α-CH3 shielded by adjacent aromatic rings and dehydrogenation of naphthenic rings. When the previously-formed anisotropic phase under the liquid-state carbonized conditions for a long time, the second-stage aging of mesophase is readily triggered through the elimination of the α-CH3 not shielded by adjacent aromatic rings. This gives rise to the intermolecular polymerization and a shift towards higher molecular weight. This study provides insights into the preparation of excellent melt-fluidity mesophase pitch by promoting the rapid transformation of the isotropic matrix before significant aging of the coexisting anisotropic phase.

Metal Mo and nonmetal N, S co-doped 3D flowers-like porous carbon framework for efficient electromagnetic wave absorption

The carbon-based material co-doped with metal and nonmetal can induce electron spin redistribution and polarization configuration transformation, and consequently affected the electromagnetic wave absorption (EWA) performance. To explore this effect, we masterly prepared Mo and N, S co-doped 3D flower-like porous carbon framework (Mo/N/S-PCF) by pyrolysising the modified ZIF(Zn)-L. The EWA properties of N-PC, Mo/N-PCF and Mo/N/S-PCF show a trend of gradual enhancement. In addition, the calcination temperature plays a decisive role in regulating the amount of doping, the degree of graphitization and EWA properties of Mo/N/S-PCF. When the pyrolysis temperature is 900 °C, the optimum reflection loss of Mo/N/S-PCF can reach −53dB only with the thickness of 1.7 mm. Excellent performance of Mo/N/S-PCF is attributed to the increased dipole polarization that caused by the Mo, N and S co-doped in the carbon skeleton.

Origami-Inspired Design of a Single-Degree-of-Freedom Reconfigurable Wing With Lockable Mechanisms

Abstract The morphing wing can enable the aircraft to maintain good flight performance in different missions or flight stages, which has enjoyed much attention in recent research. However, it is difficult to design the wing with multiple configurations and lightweight. Inspired by the origami art, a reconfigurable mechanism with a single-degree-of-freedom (single-DOF) is introduced to the morphing wing design in this paper. The bending configuration, the deployable configuration, and the configuration transformation of the reconfigurable mechanism are respectively analyzed. The lengths of some links are also optimized according to the motion requirements. Specific kinematic pairs of the reconfigurable mechanism are required to have the locking function. Therefore, a reliable “plug-in” type lockable mechanism is designed and its working performance is verified by comparing the analytical model and the finite element method model. Finally, by assembling the reconfigurable mechanism with the ribs, the reconfigurable wing which can realize the arbitrary transformation of four configurations under a single drive mode can be obtained.

Surface oxygen vacancy-dependent molecular oxygen activation for propane combustion over α-MnO2

Oxygen vacancies (OV), as the sites of molecular oxygen adsorption and activation, play an important role in the catalytic combustion process of volatile organic compounds (VOCs). Revealing the relationship between OV concentration and molecular oxygen activation behavior is of significance to construct the efficient catalysts. Herein, α-MnO2 with different OV concentrations was prepared to investigate the molecular oxygen activation for C3H8 combustion. It is disclosed that the enhanced OV concentration in α-MnO2 induced the reconfiguration of surface metal atoms, resulting in the transformation of oxygen activation configuration from end-on mode to side-on mode. Oxygen molecules in side-on mode possessed more localized electron density and weaker coordination bond strength with surrounding Mn atoms, which were more favorable to adsorb C3H8 molecules and activate C-H bond for the improved combustion performance. This work provides a new understanding to reveal that the increased OV concentration contributes to more efficient VOCs combustion.

M2STaR: A Multimode Spatio-Temporal Redundancy Design for Fault-Tolerant Coarse-Grained Reconfigurable Architectures

Coarse-grained reconfigurable architectures (CGRAs) can provide both energy efficiency and performance for embedded systems, and thus they are increasingly deployed in the areas of aerospace, automotive engineering, and security where reliability is also a main criterion. However, the state-of-the-art fault-tolerant strategies for CGRAs apply either temporal or spatial scheme, including redundancy, periodic detection, workload balancing, and reconfiguration, failing to exploit the feature of dynamic and partial reconfiguration of CGRAs. Also, vulnerable judging circuits and inflexible mode shifting bottleneck the reliability design of fault-tolerant CGRAs. This paper proposes a novel multi-mode fault-tolerant framework for CGRAs, which combines spatial-redundant data-paths with temporal-redundant voters and thus reduces the vulnerable judging circuits while balancing the performance and reliability. This framework can also enable a changing reliability level at runtime via an online configuration transformation method based on pre-compiled patterns. Within the proposed framework, we systematically searched the design space spanning various combinations of the mainstream schemes with a Markov process model to compare the effectiveness and accordingly selected five points as available modes in our design after comprehensive consideration of fault tolerance and time overhead on CGRA. The framework is comprehensively evaluated on a cycle-accurate CGRA simulator, considering both permanent and transient faults. The experimental results show that the fault coverage rate of single transient faults or permanent faults has increased from 71.74% to 93.84%, which means the fault tolerance of the system has been increased by 31.03% compared with the state-of-the-art methods. There is also a great improvement in mean-time-to-failure (MTTF) and reconfiguration latency over baseline designs.

Activating dynamic atomic-configuration for single-site electrocatalyst in electrochemical CO2 reduction

One challenge for realizing high-efficiency electrocatalysts for CO2 electroreduction is lacking in comprehensive understanding of potential-driven chemical state and dynamic atomic-configuration evolutions. Herein, by using a complementary combination of in situ/operando methods and employing copper single-atom electrocatalyst as a model system, we provide evidence on how the complex interplay among dynamic atomic-configuration, chemical state change and surface coulombic charging determines the resulting product profiles. We further demonstrate an informative indicator of atomic surface charge (φe) for evaluating the CO2RR performance, and validate potential-driven dynamic low-coordinated Cu centers for performing significantly high selectivity and activity toward CO product over the well-known four N-coordinated counterparts. It indicates that the structural reconstruction only involved the dynamic breaking of Cu–N bond is partially reversible, whereas Cu–Cu bond formation is clearly irreversible. For all single-atom electrocatalysts (Cu, Fe and Co), the φe value for efficient CO production has been revealed closely correlated with the configuration transformation to generate dynamic low-coordinated configuration. A universal explication can be concluded that the dynamic low-coordinated configuration is the active form to efficiently catalyze CO2-to-CO conversion.