Formation Process Research Articles

Технология использования мультипликационных фильмов в обучении бурятскому языку детей дошкольного возраста

The Buryat language is in danger of extinction. Vitality of the language is determined by children's use of it. At present, there is an urgent need in the republic to develop and apply in the process of teaching the Buryat language such technologies that will be interesting and demanded by pre-school children. The purpose of the study is to show the possibilities of using cartoons in the process of teaching Buryat language as a second language to preschool children. In the course of the study we applied the following methods: generalization of experience in teaching Buryat language as a second language to preschool children, analysis of scientific literature on the methods of early foreign language teaching, speech development of preschool children, use of cartoons in language classes, observation of the process of language skills formation in preschool children, experimental and pedagogical work, conversation with Buryat language teachers of preschool educational organizations of the Republic of Buryatia. The study revealed that cartoons created in the Buryat language have a great didactic potential. To use them for the purpose of teaching the Buryat language, a selection of cartoon series was made and a set of tasks for them was developed. This set of tasks realizes the methods of teaching second languages and the algorithm of work on video materials. Scientific novelty of the study consists in methodical analysis of the teaching potential of cartoons in the Buryat language, the study of linguistic and speech content of cartoon texts and the possibility of using them in the formation of linguistic skills and the development of technology of using these cartoons in teaching the Buryat language to preschool children. The practical significance of the study lies in the description of a set of tasks for working on cartoons, which makes it possible to use the results of the study in the development of new technologies of teaching Buryat language and other languages with the use of cartoons, in particular, in the development of a set of tasks and exercises for different types of language and speech skills, in the creation of educational cartoons.

Neural Technologies for Objects Classification with Mobile Applications

This paper is related to the study of the features of the neural technologies’ application, in particular, ResNet neural networks for the classification of objects in photographs. The work aims to increase the accuracy of recognition and classification of objects in photographs by using various models of the ResNet neural network. The paper analyzes the features of the application of the corresponding models in comparison with other architectures of deep neural networks and evaluates their efficiency and accuracy in the classification of objects in photographs. The process of data formation for training neural networks, their processing and sorting is described. A web application and a mobile application for recognizing and classifying objects in a photo were also developed. A system for classifying objects, in particular airplanes in photographs, was developed using neural network technologies. It gives a recognition and classification accuracy of about 95%. Research results of ResNet models are of great practical importance, as they can improve the classification accuracy of various images. Features of ResNet, such as the use of skip connections or residual connections, make it effective in the relevant tasks. The results of the study will help to implement ResNet in various fields, including medicine, automatic pattern recognition and other areas where the classification of objects in photographs is an important task.

Triple-Dearomative Photocycloaddition: A Strategy to Construct Caged Molecular Frameworks.

An unprecedented caged 2H-benzo-dioxo-pentacycloundecane framework was serendipitously obtained in a single transformation via triple-dearomative photocycloaddition of chromone esters with furans. This caged structure was generated as part of an effort to access a tricyclic, oxygen-bridged intermediate enroute to the dihydroxanthone natural product nidulalin A. Reaction scope and limitations were thoroughly investigated, revealing the ability to access a multitude of synthetically challenging caged scaffolds in a two-step sequence. Photophysical studies provided key mechanistic insights on the process for formation of the novel caged scaffold.

PRDM14 extinction enables the initiation of trophoblast stem cell formation

Trophoblast stem cells (TSCs) can be chemically converted from embryonic stem cells (ESCs) in vitro. Although several transcription factors (TFs) have been recognized as essential for TSC formation, it remains unclear how differentiation cues link elimination of stemness with the establishment of TSC identity. Here, we show that PRDM14, a critical pluripotent circuitry component, is reduced during the formation of TSCs. The reduction is further shown to be due to the activation of Wnt/β-catenin signaling. The extinction of PRDM14 results in the erasure of H3K27me3 marks and chromatin opening in the gene loci of TSC TFs, including GATA3 and TFAP2C, which enables their expression and thus the initiation of the TSC formation process. Accordingly, PRDM14 reduction is proposed here as a critical event that couples elimination of stemness with the initiation of TSC formation. The present study provides novel insights into how induction signals initiate TSC formation.

Perovskite Colloidal Nanocrystal Solar Cells: Current Advances, Challenges and Future Perspectives.

The power conversion efficiencies (PCEs) of polycrystalline perovskite (PVK) solar cells (SCs) (PC-PeSCs) have been rapidly increased. However, PC-PeSCs are intrinsically unstable without encapsulation, and their efficiency drops during large-scale production; these problems hinder the commercial viability of PeSCs. Stability can be increased by using colloidal PVK nanocrystals (c-PeNCs), which have high surface strains, low defect density, and exceptional crystal quality. Use of c-PeNCs separates the crystallization process from film formation process, which is preponderant in large-scale fabrication. Consequently, use of c-PeNCs has substantial potential to overcome challenges encountered when fabricating PC-PeSCs. Research on colloidal nanocrystal-based PVK SCs (NC-PeSCs) has increased their PCEs to the level greater than those of other quantum-dot SCs, but has not reached the PCEs of PC-PeSCs; this inferiority significantly impedes widespread application of NC-PeSCs. This review at first introduces the distinctive properties of c-PeNCs, then the strategies that have been used to achieve high-efficiency NC-PeSCs. Then it discusses in detail the persisting challenges in this domain. Specifically, the major challenge and solutions for NC-PeSCs related to low short-circuit current density Jsc are covered. Lastly, the article presents a perspective on future research directions and potential applications in the realm of NC-PeSCs. This article is protected by copyright. All rights reserved.

Impact of Migration on Identity Formation: A Study of Second-Generation Immigrants

Purpose: This study sought to explore the impact of migration on identity formation looking at the second generation immigrants. Methodology: The study adopted a desktop research methodology. Desk research refers to secondary data or that which can be collected without fieldwork. Desk research is basically involved in collecting data from existing resources hence it is often considered a low cost technique as compared to field research, as the main cost is involved in executive’s time, telephone charges and directories. Thus, the study relied on already published studies, reports and statistics. This secondary data was easily accessed through the online journals and library. Findings: The findings reveal that there exists a contextual and methodological gap relating to the impact of migration on identity formation. Preliminary empirical review revealed that migration experiences profoundly influenced the construction of cultural identities. Through an analysis of diverse experiences, the study revealed the heterogeneous nature of identity trajectories among second-generation immigrants, ranging from strong attachment to ethnic heritage to fluid, hybrid identities. Socio-cultural factors such as family dynamics, socio-economic status, and institutional support played significant roles in shaping individuals' identity formation processes. The findings emphasized the importance of inclusive policies and supportive networks in facilitating positive identity development among second-generation immigrants, contributing to a deeper understanding of identity construction in multicultural societies. Unique Contribution to Theory, Practice and Policy: The Social Identity theory, Intersectionality theory and Acculturation theory may be used to anchor future studies on the impact of migration on identity formation. The study made significant contributions to theory, practice, and policy by elucidating the complex interplay between migration experiences and identity formation among second-generation immigrants. Drawing upon established theories such as Social Identity Theory, Intersectionality Theory, and Acculturation Theory, the study provided a nuanced understanding of the factors shaping identity trajectories. Recommendations included implementing culturally responsive teaching practices, developing interventions to support psychosocial well-being, and adopting inclusive integration policies. These insights empowered educators, mental health professionals, community organizations, and policymakers to create more inclusive and supportive environments for second-generation immigrants navigating their identities within the context of migration.

RUSSIAN TRADE COOPERATION: FORMING A STRATEGIC PARTNERSHIP IN THE CONTEXT OF SANCTIONS

Under the conditions of sanctions confrontation transformation of trade and economic relations in the world arena is inevitable. This article analyzes the process of Russian formation of strategic trade cooperation within the global economic system in the context of the evolution of the geography of international trade in 2022–2023. The methodology is based on comparative and statistical approaches. The study shows the growing importance of strategic partnership with China, India and Turkey against the background of the slowdown in trade relations between Russia and the European Union after February 2022. The author's opinion is that the concentration of major commodity flows in a rather narrow group of states has several negative consequences. As the analysis has shown, there is a need to rethink the strategy of Russia's international economic cooperation in the direction of diversification of its economic ties. The purpose of the study is to develop recommendations to support domestic non-resource nonenergy exports (NRE) as a source of sustainable development of trade relations in the direction of friendly countries in the new economic reality. The article identified the most important partner countries for Russian non-resource non-energy exports (China, Kazakhstan, Turkey, Belarus, Uzbekistan and Egypt), which at the same time have the highest indicator of unrealized export potential. Based on the results of the research, it was developed recommendations how to expand the geography of Russian non-resource non-energy exports in the direction of identified strategic partners in the conditions of the sanctions.

Facies analysis, depositional environment and diagenetic processes of the Lower Cretaceous Yamama Formation, Riyadh, Saudi Arabia

Facies analysis, depositional environment and diagenetic processes of the Lower Cretaceous Yamama Formation, Riyadh, Saudi Arabia

Escarpments within Mediterranean seagrass Posidonia oceanica meadows increase habitat heterogeneity and structural complexity enhancing fish diversity and biomass

Seagrass meadows provide important ecosystem services including carbon sequestration, coastal protection from erosion, and sustained biodiversity and fisheries thereby improving the wellbeing and livelihoods of coastal communities. The erosion of millenary deposits of intertwined roots and rhizomes of Posidonia results in the formation of three-dimensional structures named escarpments that constitute a biogenic reef habitat. However, the natural history of seagrass escarpments including their formation processes and their role as habitat for reef fauna and flora remains poorly understood. This research located and characterized Posidonia oceanica escarpments in Menorca (Balearic Islands) and compared structural complexity and fish assemblages among seagrass escarpments, seagrass meadows, rocky substrates and bare sand with emphasis on its role as habitat and shelter for typical rocky fish. Fish abundance and biomass were similar between seagrass escarpments and rocky substrates (P > 0.05), but significantly lower in seagrass meadows (P < 0.001). The large number of caves found along seagrass escarpments provide shelter to fish, including species only associated to rocky substrates. Seagrass meadows form a rather homogenous habitat within their canopy, but the presence of seagrass escarpments enhances habitat heterogeneity and structural complexity along with fish abundance and biomass at the seascape level. This study enhances understanding on the ecological importance of seagrass escarpments.

CAPILLARY PROCESSES DURING FLOODING OF LAYERED-HETEROMOGENEOUS PRODUCTIVE FORMATIONS

The paper presents an analysis of existing laboratory methods for determining capillary pressure functions used in mathematical and computer modeling of the processes of capillary impregnation of low-permeability layers of layered heterogeneous hydrophilic reservoirs during their flooding.It is shown that in existing methods for determining capillary pressure functions in rock samples using capillarimeters and high-speed centrifuges, the factor of the formation of residual oil in the pore space of the rock is not taken into account. At the same time, the processes of displacement of oil by water from productive formations and, in particular, the processes of capillary impregnation of the rock, are characterized by the processes of formation of microvolumes precisely of immobile residual oil in its pore space. Meanwhile, when conducting laboratory studies of rock samples using existing methods, another process is physically reproduced — the process of displacement of water by oil, during which microvolumes of residual water, rather than oil, are formed.This difference in the structure of the oil-water medium leads to a significant difference between the capillary pressure functions determined by traditional methods and the capillary pressure functions that control the distribution of oil and water phases in the pore space of rocks in the processes of displacement of oil from them by water pumped into the reservoir.This difference is especially significant when flooding low-permeability rocks characterized by high capillary pressure values.The work suggests possible approaches to conducting laboratory studies of rock cores that are more consistent with the structural features of the oil-water environment during flooding of productive formations.For the most complete capillary impregnation of low-permeable layers of a layered heterogeneous formation with water from quickly watered high-permeability layers, a method is proposed that consists in the fact that the water pumped into the formation must contain the minimum required amount of oil, ensuring the mobility (connectivity) of the oil phase in the watered high-permeability layers.For this purpose, water from production wells containing a certain amount of residual oil can be used for injection into the reservoir. The economic feasibility of the proposed method should be justified by the results of computer modeling of capillary impregnation processes, taking into account the described features of capillary pressure functions characteristic ofprocesses of oil displacement from productive formations during their waterflooding.

ALMA-IMF XI. The sample of hot core candidates: A rich population of young high-mass protostars unveiled by the emission of methyl formate

The star formation process leads to an increased chemical complexity in the interstellar medium. Sites associated with high-mass star and cluster formation exhibit a so-called hot core phase, characterized by high temperatures and column densities of complex organic molecules. We aim to systematically search for and identify a sample of hot cores toward the 15 Galactic protoclusters of the ALMA-IMF Large Program and investigate their statistical properties. We built a comprehensive census of hot core candidates toward the ALMA-IMF protoclusters based on the detection of two mf emission lines at 216.1\,GHz. We used the source extraction algorithm GExt2D to identify peaks of methyl formate ( emission, a complex species commonly observed toward sites of star formation. We performed a cross-matching with the catalog of thermal dust continuum sources from the ALMA-IMF 1.3\,mm continuum data to infer their physical properties. We built a catalog of 76 hot core candidates with masses ranging from sim 0.2\,Msun to sim 80\,Msun , of which 56 are new detections. A large majority of these objects, identified from methyl formate emission, are compact and rather circular, with deconvolved full width at half maximum (FWHM) sizes of sim \,2300\,au on average. The central sources of two target fields show more extended, but still rather circular, methyl formate emission with deconvolved FWHM sizes of sim 6700\,au and 13400\,au. About 30<!PCT!> of our sample of methyl formate sources have core masses above 8\,Msun and range in size from sim \,1000\,au to 13400\,au, which is in line with measurements of archetypical hot cores. The origin of the emission toward the lower-mass cores may be explained as a mixture of contributions from shocks or may correspond to objects in a more evolved state (i.e., beyond the hot core stage). We find that the fraction of hot core candidates increases with the core mass, suggesting that the brightest dust cores are all in the hot core phase. Our results suggest that most of these compact methyl formate sources are readily explained by simple symmetric models, while collective effects from radiative heating and shocks from compact protoclusters are needed to explain the observed extended mf emission. The large fraction of hot core candidates toward the most massive cores suggests that they rapidly enter the hot core phase and that feedback effects from the forming protostar(s) impact their environment on short timescales.

The separate effect of halo mass and stellar mass on the evolution of massive disk galaxies

Abstract We analyse a sample of massive disk galaxies selected from the SDSS-IV/MaNGA survey to investigate how the evolution of these galaxies depends on their stellar and halo masses. We applied a semi-analytic spectral fitting approach to the data from different regions in the galaxies to derive several of their key physical properties. From the best-fit model results, together with direct observables such as morphology, colour, and the Mgb/〈Fe〉 index ratio measured within 1Re, we find that for central galaxies both their stellar and halo masses have a significant influence in their evolution. For a given halo mass, galaxies with higher stellar mass accumulate their stellar mass and become chemically enriched earlier than those with smaller stellar mass. Furthermore, at a given stellar mass, galaxies living in more massive halos have longer star-formation timescales and are delayed in becoming chemically enriched. In contrast, the evolution of massive satellite galaxies is mostly determined by their stellar mass. The results indicate that both the assembled halo mass and the halo assembly history impact the evolution of central galaxies. Our spatially resolved analysis indicates that only the galaxy properties in the central region (0.0–0.5Re) show the dependencies described above. This fact supports a halo-driven formation scenario since the galaxies’ central regions are more likely to contain old stars formed along with the halo itself, keeping a memory of the halo formation process.

Synthesis and characterization of CuxCd1‐xS nanocrystals into functionalized nitrile butadiene rubber matrix

AbstractIntroductionPolymetallic sulfides and heterostructures like CdIn2S4, CdZnS2, CuxS‐NiySz, Cu2CoSnS4, CoNi2S4, Zn0.76Co0.24S have been fabricated with various shapes and forms for new applications. Ternary copper cadmium sulfides (CuCdS2) are a p‐type semiconductor with a direct band gap of about 2.4 eV forms very good nanocrystals like copper sulfide could be potentially applied to optical and electronic applications. Knowing that the SILAR synthesis, optical, paramagnetic, dielectric properties, and annealing of copper cadmium sulfides have not been sufficiently investigated, they are extensively analyzed and studied in the present work.ObjectivesCuxCd1−xS (x = 0, 0.5, and 1) nanoparticles have been synthesized on the base of functionalized nitrile butadiene rubber by SILAR method and characterized using scanning electron microscopy, x‐ray diffractometer, UV–visible spectroscopy, Fourier‐transform infrared spectroscopy, electron paramagnetic resonance spectroscopy, and Raman spectroscopy. Effects of cycles, reaction time, and precursor concentration on the particle size, crystal growth and structure, bandgap energy, dielectric and paramagnetic properties, elemental composition, and morphology were investigated.MethodsThe synthesis of CuxCd1−xS nanocrystals was carried out into the obtained functional polymer matrix by SİLAR method. The functional polymer (FNBR) is a dark brown powder which contains ‐PO(OH)2 and ‐OPO(OH)2 functional groups and does not dissolve in organic and inorganic solvents, can be used as a very good stabilizer of nanostructures. The synthesis of CuxCd1−xS/FNBR nanocompsite was carried out in 3, 5, and 15 cycles.Results and discussionIn the process of ternary sulfide formation, the nucleation rate of CdS was high at the beginning of the reaction, while the growth rate and stability of CuS were high in the later course of the reaction. The average crystallite size of the nancrystallites has been increased from 1.13 nm to 7.39 nm by the increasing of the number of cycles from 5 to 15, respectively. It is explained by the inclusion of copper in the composition and getting more stable material. Copper cadmium sulfide nanostructures demonstrate wide band gap energy (~3.7 eV) in this work which is explained by the formation of nanosized particles in a limited volume of FNBR matrix.ConclusionsThe synthesis of CuxCd1‐xS nanocrystals was carried out into the obtained functional polymer matrix by SİLAR method. Strong diffraction peaks corresponding to cubic CdS are found with low SILAR cycles. SEM images of CuxCd1−xS/FNBR nanocomposite show that the atomic percentage of Cu and Cd into the ternary sulfide is 20.19% and 0.61%, respectively. It is explained by the inclusion of copper in the composition and getting more stable material with low solubility products (Ksp) which is in good agreement with XRD results. The calculated band gaps are higher than that of bulk CdS, CuS, and CuCdS2. Larger band gap is usually reported for defects or structural disorders, which is in good agreement with XRD and Raman results.

“Tell me who your friends are, and I will tell you who you are:” The contribution of peers to adolescents' values

AbstractValues serve as guiding principles, motivating specific behaviors, and actions. Peers spend a considerable amount of time together, thus offering a unique platform for the acquisition and development of values. During adolescence, a stage of life when youth are actively defining their identities, peers emerge as vital social agents, contributing significantly to the process of value formation. In this article, I examine the ways peers contribute to the development of youth's values, with a focus on basic personal values theory. This theory sheds light on how and why peers play a role in shaping the values of adolescents. It examines the phenomenon of similarity in peer values (values similarity) and explores how factors such as gender, age, and culture act as potential moderators in the relation between peers' and youth's values similarity. I conclude by summarizing key insights and proposing directions for research.

Rocks Really Rock: electronic field trips via Web Google Earth can generate positive impacts in attitudes toward Earth sciences in middle- and high-school students

Abstract. Earth sciences (ESs) are relevant to society and its relationship with the Earth system. However, ES education in K-12 environments in the United States faces several challenges, including limited exposure to ESs, lack of awareness of ES careers, and low ES literacy. International associations have recognized these challenges and recommended that Earth scientists improve the public's perception of the relevance of ES. In recent years, informal science communication and outreach platforms such as the Streaming Science model of electronic field trips (EFTs), which connect K-12 classrooms with science, engineering, technology, and mathematics (STEM) professionals, have gained popularity as an educational technology tool. EFTs are inexpensive, have spatiotemporal benefits, and have proven an effective informal science education pathway for introducing STEM content into formal classrooms to increase positive attitudes and interest in STEM careers. Nevertheless, EFTs in ES for K-12 environments have not been widely disseminated, and their impact on ES education has yet to be studied. This study presents the creation and implementation of an EFT in geology called “Rocks Really Rock: An Electronic Field Trip across Geological Time.” The program was implemented in seven schools in spring 2022. The EFT was built in Web Google Earth and had six stops that featured prerecorded videos recorded in different locations in Idaho (USA). The lead presenter or author used multimedia and science communication strategies such as storytelling to develop and teach concepts related to geological time, rock formation, and landscape-forming geological processes. The content aligned with four specific topics listed in the National Science Foundation's Earth Sciences Literacy Principles and intersected with the Next Generation Science Standards for middle-school classrooms. Participating students (n=120) completed a post-assessment after the program implementation to evaluate its impact. Results showed that the EFT positively impacted students' attitudes toward geology, geology careers, and perceptions of geology literacy. We identified the three main factors that determined a positive attitude change in K-12 students toward ES: (1) the use of videos and the Web Google Earth platform to create outreach materials for K-12 students, (2) the use of storytelling to craft the content of an EFT, and (3) the asynchronous interactions between teacher, student, and scientist. The results indicated a statistically significant positive change in attitudes toward geology, suggesting that participating in the EFT increased students' positive attitudes toward ES. These findings demonstrate the potential of expanding EFT to other ES fields and reaching middle- and high-school students. We suggest that EFTs are effective outreach tools that can address the challenges in ES education and that can be extended to other ES areas and distributed to students in middle, high, and home schools to support science educators in ES education.

Gas-phase formation of fullerene/9-hydroxyfluorene cluster cations

Abstract In interstellar environment, fullerene species readily react with large molecules (e.g. PAHs and their derivatives) in the gas phase, which may be the formation route of carbon dust grains in space. In this work, the gas-phase ion-molecule collision reaction between fullerene cations (Cn +, n = 32, 34, …, 60) and functionalized PAH molecules (9-hydroxyfluorene, C13H10O) are investigated both experimentally and theoretically. The experimental results show that fullerene/9-hydroxyfluorene cluster cations are efficiently formed, leading to a series of large fullerene/9-hydroxyfluorene cluster cations (e.g. [(C13H10O)C60]+, [(C13H10O)3C58]+, and [(C26H18O)(C13H10O)2C48]+). The binding energies and optimized structures of typical fullerene/9-hydroxyfluorene cluster cations were calculated. The bonding ability plays a decisive role in the cluster formation processes. The reaction surfaces, modes and combination reaction sites can result in different binding energies, which represent the relative chemical reactivity. Therefore, the geometry and composition of fullerene/9-hydroxyfluorene cluster cations are complicated. In addition, there is an enhanced chemical reactivity for smaller fullerene cations, which is mainly attributed to the newly formed deformed carbon rings (e.g. 7 C-ring). As part of the coevolution network of interstellar fullerene chemistry, our results suggest that ion-molecule collision reactions contribute to the formation of various fullerene/9-hydroxyfluorene cluster cations in the ISM, providing insights into different chemical reactivity caused by oxygenated functional groups (e.g. hydroxyl, OH, or ether, C-O-C) on the cluster formations.

Theoretical and experimental investigation of ultrasonic cutting kinematics and its effect on chip formation and surface generation in high-frequency ultrasonic vibration-assisted diamond cutting

Ultrasonic vibration-assisted cutting (UVAC) is regarded as a feasible technology to machine difficult-to-cut materials. High-frequency ultrasonic vibration-assisted cutting (HFUVAC), with a working frequency of more than low and medium frequency (20-60kHz), has been reported to improve material machinability and prolong tool life. This paper presents a comprehensive investigation of the ultrasonic cutting kinematics and the generated chip/surface formation process in HFUVAC of a 316l stainless steel workpiece. First, the ultrasonic cutting kinematics was analyzed and verified by comparing the experimental and theoretical surface texture under different nominal cutting speeds. Based on the ultrasonic cutting kinematics and the simulated strain/stress distributions, the chip and surface formation between conventional cutting (CC) and HFUVAC was analyzed. More importantly, the incremental cutting mode was defined when the cutting stroke, namely the effective cutting length in one vibration cycle was less than 800 nm. The results show that in the incremental cutting mode, defect-free surface was achieved due to suppressed large deformation and friction action. Finally, HFUVAC of the sinusoidal microstructure was performed under the incremental cutting mode, achieving optical requirements with nanometer-scale surface roughness and submicrometric form accuracy, which validates the technical feasibility in HFUVAC of micro-structured surfaces.

The acceleration of the active phase transition of NiCoFe hydroxide by Ta doping to achieve Long-Time seawater electrolysis at Ampere-Level current density

Considering the regional distribution of freshwater resources, acquiring hydrogen by seawater electrolysis has lower cost and feasibility. NiCoFe-based materials have been widely studied due to their excellent catalytic oxidation performance in freshwater. However, the large amount of chloride ions in seawater will severely erode the catalytic site and greatly reduce the catalyst's lifetime. In this paper, a two-dimensional nanosheet quaternary metal hydroxide electrode composed of Ni, Co, Fe, and Ta elements was synthesized via a facile one-step hydrothermal method for efficient oxygen evolution reaction (OER) in seawater electrolysis. Structural characterization and in-situ test revealed that the incorporation of Ta not only optimized the electronic structure of the catalyst but also accelerated the formation of the γ-NiOOH phase, making the active phase is protected from being attacked by Cl- ions during the formation process, enhancing its OER activity while achieving extended durability. The catalyst was operated at an ampere-level of 1 A cm-2 for over one month (800 h), and no significant degradation was observed. This work provides a promising strategy for developing cost-effective, efficient, and stable catalysts for challenging applications in seawater electrolysis.

Exploring the Deprotonation Process during Incorporation of a Ligand Water Molecule at the Dangling Mn Site in Photosystem II.

The Mn4CaO5 cluster, featuring four ligand water molecules (W1 to W4), serves as the water-splitting site in photosystem II (PSII). X-ray free electron laser (XFEL) structures exhibit an additional oxygen site (O6) adjacent to the O5 site in the fourth lowest oxidation state, S3, forming Mn4CaO6. Here, we investigate the mechanism of the second water ligand molecule at the dangling Mn (W2) as a potential incorporating species, using a quantum mechanical/molecular mechanical (QM/MM) approach. Previous QM/MM calculations demonstrated that W1 releases two protons through a low-barrier H-bond toward D1-Asp61 and subsequently releases an electron during the S2 to S3 transition, resulting in O•- at W1 and protonated D1-Asp61. During the process of Mn4CaO6 formation, O•-, rather than H2O or OH-, best reproduced the O5···O6 distance. Although the catalytic cluster with O•- at O6 is more stable than that with O•- at W1 in S3, it does not occur spontaneously due to the significantly uphill deprotonation process. Assuming O•- at W2 incorporates into the O6 site, an exergonic conversion from Mn1(III)Mn2(IV)Mn3(IV)Mn4(IV) (equivalent to the open-cubane S2 valence state) to Mn1(IV)Mn2(IV)Mn3(IV)Mn4(III) (equivalent to the closed-cubane S2 valence state) occurs. These findings provide energetic insights into the deprotonation and structural conversion events required for the Mn4CaO6 formation.

Analysis of frost layer growth behavior on cryogenic surfaces in ultralow dew point environments by experimental tests and numerical simulations

Maintaining an ultralow dew point is essential for the operation of transonic cryogenic wind tunnels, as it significantly influences aerodynamic characteristics. Even in extremely dry conditions, minute quantities of frost can form on cryogenic surfaces, which compromises data quality. Conducting experiments on frost desublimation in such ultralow dew point environments poses significant challenges due to the demanding experimental conditions. Therefore, this study aimed to explore the desublimation characteristics of cryogenic surfaces in ultralow dew point environments and to address the challenges of experimental investigations under such extreme conditions. Initially, the study experimentally investigated frost formation by assessing the impact of various factors, such as temperature and water vapor content. It was observed that the type of frost formed depended on the water vapor content, and altering the surface temperature influenced the growth region of the frost crystals. The irregular growth of the frost layer on low-temperature surfaces was evident, as temperature markedly affected both the growth rate and the diffusion direction of frost formation. Moreover, the process of trace water frost formation was simulated using a dispersive multiphase model, predicting the frost layer's thickness. The numerical results suggest that the frost layer is micrometers thick, with a minimum thickness of 20 μm. A nonlinear relationship was identified between frost growth and dew point level. This research lays the groundwork for a deeper understanding of desublimation characteristics in ultralow dew point environments and for further investigation of low-temperature heat and mass transfer phenomena.