bluuebunny/crossref_metadata_2025 huggingface dataset:
Design and Control Strategies for a 25 kW LLC Converter with a Wide Output Voltage Range Comprising Distributed Core Transformers
Authors: Sim Dong Hyeon , Lee Ju-A. , Lee Byoung Kuk
Published: February 2025

This paper presents the design and experimental validation of a 25 kW LLC converter for a 50 kW electric vehicle (EV) fast charging system (FCS) module, emphasizing a broad output voltage range. The resonant network of the LLC converter is analyzed to ensure optimal operational efficiency, and the half-bridge control method is explored to accommodate extensive voltage range. The converter features a distributed core transformer, focusing on the evaluation of connection methods for enhanced power density and efficient heat dissipation. Based on these analyses, an LLC converter optimized for efficient operation was developed. Experimental verification on a 25 kW testbed confirms the effectiveness and validity of the proposed design and control methods, demonstrating their substantial applicability for high-power EV charging.
AI wellbeing
Authors: Goldstein Simon , Kirk-Giannini Cameron Domenico
Published: February 2025

Under what conditions would an artificially intelligent system have wellbeing? Despite its clear bearing on the ethics of human interactions with artificial systems, this question has received little direct attention. Because all major theories of wellbeing hold that an individual’s welfare level is partially determined by their mental life, we begin by considering whether artificial systems have mental states. We show that a wide range of theories of mental states, when combined with leading theories of wellbeing, predict that certain existing artificial systems have wellbeing. Along the way, we argue that there are good reasons to believe that artificial systems can have wellbeing even if they are not phenomenally conscious. While we do not claim to demonstrate conclusively that AI systems have wellbeing, we argue that there is a significant probability that some AI systems have or will soon have wellbeing and that this should lead us to reassess our relationship with the intelligent systems we create.
Institutions and Environment in Ancient Southern East Asia (3000 BCE to 300 CE)
Authors: Korolkov Maxim
Published: February 2025

Over the past decades, archaeological exploration of southern China has shattered the image of primitive indigenous people and their pristine environments. It is known, for example, that East Asia's largest settlements and hydraulic infrastructures in the third millennium BCE were located in the Yangzi valley, as were some of the most sophisticated metallurgical centers of the following millennium. If southern East Asia was not a backward periphery of the Central Plains, then what created the power asymmetry that made possible 'China's march toward the Tropics'? What did becoming 'Chinese' practically mean for the local populations south of the Yangzi? Why did some of them decide to do so, and what were the alternatives? This Element focuses on the specific ways people in southern East Asia mastered their environment through two forms of cooperation: centralized and intensive, ultimately represented by the states, and decentralized and extensive, exemplified by interaction networks.
Sea Ice Heterogeneity as a Result of Ocean Eddy Activity During the Ice Growth Season
Authors: Martínez‐Moreno Josué , Lique Camille , Talandier Claude
Published: February 2025

Mesoscale eddies, generated by lateral gradients in salinity and temperature in the Arctic marginal ice zone, are known to modulate the melting of sea ice. Yet, it remains unclear if eddies modify sea ice growth during the freezing season. Here, we use idealized spin‐down simulations of a front to explore the sea ice growth above an eddying ocean. In the presence of eddies, mixing of the sea surface temperature and salinity induces spatial variability in the heat and salt fluxes at the ice‐ocean interface, imprinting spatial variability on the sea ice thickness. Sea ice thickness shows an order of magnitude more spatial variability in our simulations with strong eddies compared to those without. Increased spatial heterogeneity in the sea ice could make it more brittle and affect its evolution. This effect may become more pronounced as the Arctic transitions to a summer open‐ocean regime and the eddy field intensifies.
Magnetotelluric Evidence for Lithospheric Hydration and Thinning Beneath the Youjiang Basin in Southwestern China
Authors: Yang Zhen , Li Xin , Deng Yangfan , Yu Nian , Kong Wenxin , Chen Minghao , Chen Yun , Bai Denghai , Teng Jiwen
Published: February 2025

Determining the water content in the lithospheric mantle is crucial for understanding its dynamic evolution. Because the electrical conductivity of mantle minerals is particularly sensitive to water, the magnetotelluric (MT) method becomes a vital tool to determine the water content in the lithospheric mantle. Here we used broadband and long‐period MT data collected along a 600‐km‐long, NS‐trending profile to obtain the electrical resistivity structure of the lithosphere across the southwestern South China Block. By combining the results of laboratory electrical conductivity measurements of mantle minerals, xenolith‐derived composition, and geotherm information, we further estimated the water content of the lithospheric mantle. The results show that the Youjiang Basin has a relatively thin lithosphere segmented by zones of low‐resistivity that spatially coincide with major faults. The relatively conductive mantle lithosphere could be explained by the combined effects of water in nominally anhydrous minerals, sulfide and phlogopite. Combined with regional tectonic context, we proposed that H2O‐rich fluids derived from the previously subducted slabs and related metasomatic processes lead to lithospheric hydration and thinning within the Youjiang Basin. Additionally, such processes, together with magmatic‐hydrothermal activities, likely contribute to the formation of gold deposits within the basin. By contrast, the lithosphere beneath the Yangtze Craton is characterized by high resistivity extending to a depth of ∼200 km, representing a typical cratonic lithosphere that has not undergone significant tectonic modification and contains no or very little water.
A Scheme of Sea Surface Upward Longwave Radiation With Sea Spray Layer Effect
Authors: Jing Xueyi , Wang Lanning , Wu Qizhong , Cheng Huaqiong
Published: February 2025

Estimation of sea surface upward longwave radiation (SULR) are generally dependent on sea surface temperature (SST), in accordance with the Stefan‐Boltzmann law. The consensus is that the inaccuracy in estimating SST contributes to bias in the estimation. This study proposes the incorporation of the spray layer in estimating upward longwave radiation, as when the sea surface is covered by the spray layer, it becomes the primary source of longwave radiation emitted to the atmosphere. Analysis of ERA5 data suggests that the bias in sea SULR is associated with the temperature of the sea spray layer and the whitecap coverage. Incorporating the spray layer in the estimation of sea SULR results in a decrease of the overestimation in ERA5 by over 15%. The revised scheme, implemented in CESM2.1.3, led to an average percentage bias improvement around 16%. The percentage bias improvement in localized areas of the southeastern Pacific and the southeastern Indian Oceans reaches up to 40%. The regions where bias has been effectively reduced are mainly found within latitudes of 30°, and the negative bias in the Southern Ocean is increased. This study offers a novel insight into the errors in estimating sea SULR.
Enhanced Simulation of Atmospheric Blocking in a High‐Resolution Earth System Model: Projected Changes and Implications for Extreme Weather Events
Authors: Gao Yang , Guo Xiaojie , Lu Jian , Woolings Tim , Chen Deliang , Guo Xiuwen , Kou Wenbin , Zhang Shaoqing , Leung L. Ruby , Schiemann Reinhard , O'Reilly Christopher H. , Guo Chuncheng , Li Jianping , Gao Huiwang , Wu Lixin
Published: February 2025

Atmospheric blocking is closely linked to the occurrence of extreme weather events. However, low‐resolution Earth system models often underestimate the frequency of blocking, undermining confidence in future projections. In this study, we use the high‐resolution Community Earth System Model (CESM‐HR; 25 km atm and 10 km ocean) to show that CESM‐HR reduces biases in atmospheric blocking for both winter and summer, particularly for events lasting longer than 10 days. This improvement is partly due to reduced sea surface temperature biases at higher resolution. Additionally, applying a bias correction to the 500 hPa geopotential height further enhances blocking frequency simulations, highlighting the crucial role of the mean state. Under the Representative Concentration Pathway 8.5 scenario, CESM‐HR projects a decrease in wintertime blocking over regions such as the Euro‐Atlantic and Chukchi‐Alaska, consistent with previous studies. In contrast, summer blocking is expected to become more frequent and persistent, driven by weakened zonal winds. The blocking center shifts from historical locations over Scandinavia and eastern Russia to central Eurasia, significantly increasing blocking over the Ural region. Summer blocking frequency over the Scandinavia‐Ural region may eventually surpass historical winter blocking over the Euro‐Atlantic. This increase in summer blocking could exacerbate summer heatwaves in a warming climate, making severe heatwaves, like those observed recently, more common in the future.
South European Heatwaves and Their Impacts on the Power System in 2022
Authors: Xu Xinping , He Shengping , Zhou Botao , Wang Huijun , Jiang Han , Liu Changyi , Sun Bo , Yin Tienan , Yan Jie
Published: February 2025

Unprecedented heatwaves accompanying severe droughts hit South Europe in May‒July 2022. From the interdisciplinary perspective, this study revealed that the extreme climate events can intensify European energy crisis through pushing up electricity demand and limiting renewable energy supply that makes up more than one‐third of gross electricity consumption in the European Union (EU). The record‐high electricity demand over South Europe in May‒July was closely associated with the long‐lasting extreme heatwaves. On the other hand, the anomalous high‐pressure system over Europe contributed to the severe heatwaves and the shortage of renewable power generation, for instance, through affecting the wind speed. The wind power generation over South Europe was reduced by the anomalous anticyclone which weakened low‐tropospheric prevailing northwesterly wind. The results indicate a potential intensive conflict between the increasing power demand and the decreasing renewable power generation in Europe that are induced simultaneously by the extreme heatwaves. Therefore, it is suggested that the energy sectors' resilience to extreme climate events should be well built as the EU sets to significantly increase the renewable energy target to meet the goal of climate‐neutral by 2050.
An Upgraded Alvin Puts New Ocean Depths Within Reach
Authors: Rubin Kenna , Michel Anna , Soule S.
Published: February 2025

The newly retooled submersible, which has already returned fascinating new findings from Earth’s watery depths, is opening more of the deep ocean to direct human exploration.
miR-142 deficit in T cells during blast crisis promotes chronic myeloid leukemia immune escape
Authors: Chen Fang , Zhao Dandan , Xu Yongfang , Zhang Yi , Chen Min-Hsuan , Pathak Khyatiben V. , Hansen Nate , Lovell Brooke , Liang Yong , Estrella Katrina , Wang Wei-Le , Ghoda Lucy , Rockne Russell , Wu Xiwei , Ali Haris , Yu Jianhua , Caligiuri Michael A. , Forman Stephen J. , Trent Jeff M. , Kuo Ya-Huei , Li Ling , Swiderski Piotr , Zhang Jianying , Kortylewski Marcin , Nguyen Le Xuan Truong , Pirrotte Patrick , Boldin Mark , Marcucci Guido , Zhang Bin
Published: February 2025

We reported that an acquired miR-142 deficit transforms chronic phase (CP) chronic myeloid leukemia (CML) leukemic stem cells (LSCs) into blast crisis (BC) LSCs. Given the role of miR-142 in the development and activity of the immune system, we postulated that this deficit also promotes LSC immune escape. Herein, we report on IL-6-driven miR-142 deficit occurring in T cells during BC transformation. In CML murine models, miR-142 deficit impairs thymic differentiation of lymphoid-primed multipotent progenitors (LMPP) into T cells and prevents T cells’ metabolic reprogramming, thereby leading to loss of T cells and leukemia immune escape. Correcting miR-142 deficit with a miR-142 mimic compound (M-miR-142), alone or in combination with immune checkpoint antibodies, restores T cell number and immune activity, leading to LSC elimination and prolonged survival of BC CML murine and patient-derived xenograft models. These observations may open new therapeutic opportunities for BC CML and other myeloid malignancies.
Machine learning assisted composition design of high-entropy Pb-free relaxors with giant energy-storage
Authors: Wang Xingcheng , Zhang Ji , Ma Xingshuai , Luo Huajie , Liu Laijun , Liu Hui , Chen Jun
Published: February 2025

The high-entropy strategy has emerged as a prevalent approach to boost capacitive energy-storage performance of relaxors for advanced electrical and electronic systems. However, exploring high-performance high-entropy systems poses challenges due to the extensive compositional space. Herein, with the assistance of machine learning screening, we demonstrated a high energy-storage density of 20.7 J cm-3 with a high efficiency of 86% in a high-entropy Pb-free relaxor ceramic. A random forest regression model with key descriptors based on limited reported experimental data were developed to predict and screen the elements and chemical compositions of high-entropy systems. Following basic experiments, a (Bi0.5Na0.5)TiO3-based high-entropy relaxor characterized by fine grains, weakly-coupled and small-sized polar clusters was identified. This resulted in a near-linear polarization behavior and an ultrahigh breakdown strength of 95 kV mm-1. Further, this high-entropy realxor presented a high discharge energy density of 7.7 J cm-3 under discharge rate of about 27 ns, along with superior temperature and fatigue stability. Our results present the data-driven model for efficiently exploring high-performance high-entropy relaxors, demonstrating the potential of machine learning in developing relaxors.
A hybrid Prairie INFO fission naked algorithm with stagnation mechanism for the parametric estimation of solar photovoltaic systems
Authors: Sharma Pankaj , Salgotra Rohit , Raju Saravanakumar , Abouhawwash Mohamed , Askar S. S.
Published: February 2025

This paper presents a study to enhance the performance of a recently introduced naked mole-rat algorithm (NMRA), by local optima avoidance, and better exploration as well as exploitation properties. A new set of algorithms, namely Prairie dog optimization algorithm, INFO, and Fission fusion optimization algorithm (FuFiO) are included in the fundamental framework of NMRA to enhance the exploration operation. The proposed algorithm is a hybrid algorithm based on four algorithms: Prairie Dog, INFO, Fission Fusion and Naked mole-rat (PIFN) algorithm. Five new mutation operators/inertia weights are exploited to make the algorithm self-adaptive in nature. Apart from that, a new stagnation phase is added for local optima avoidance. The proposed algorithm is tested for variable population, dimension size, and efficient set of parameters is analysed to make the algorithm self-adaptive in nature. Friedman as well as Wilcoxon rank-sum tests are performed to determine the effectiveness of the PIFN algorithm. On the basis of a comparison of outcomes, the PIFN algorithm is more effective and robust than the other optimization techniques evaluated by prior researchers to address standard benchmark functions (classical benchmarks, CEC 2017, and CEC-2019) and complex engineering design challenges. Furthermore, the effectiveness as well as reliability of the PIFN algorithm is demonstrated by testing using various PV modules, namely the RTC France Solar Cell (SDM, and DDM), Photowatt-PWP201, STM6- 40/36, and STP6-120/36 module. The results obtained from the PIFN algorithm are compared with various MH algorithms reported in the existing literature. The PIFN algorithm achieved the lowest root-mean-square error value, for RTC France Solar Cell (SDM) is 7.72E−04, RTC France Solar Cell (DDM) is 7.59E−04, STP6-120/36 module is 1.44E−02, STM6-40/36 module is 1.723E−03, and Photowatt-PWP201 module is 2.06E−03, respectively. In order to enhance the accuracy of the obtained results of parameter estimation of solar photovoltaic systems, we integrated the Newton-Raphson approach with the PIFN algorithm. Experimental and statistical results further prove the significance of the PIFN algorithm with respect to other algorithms.
Fully automated CFD simulation system research based on design scheme tree
Authors: Liu Zijun
Published: February 2025

Compared with the remarkable achievements of computer-aided drug discovery systems for drug discovery, the role of computational fluid dynamics (CFD) in flow channel design requires further development. While CFD has undergone rapid evolution, the absence of integrated geometry and mesh processing hinders the potential development of advanced applications of this technology. To overcome this limitation, in this paper, the JIACFD toolset is presented, and a fully automated CFD simulation system is established. The simulation system is also constructed on a design scheme tree, which is more in accordance with engineering logic. The control parameter trend analysis method is introduced to select appropriate candidates from the design scheme tree. Additionally, the control parameter trend assumption, which is proven via the Spearman method, is proposed to improve the efficiency of the system. During the verification process for the study case, two independent control parameters exhibit correlating trends, and one control parameter converges when the number of meshes increases, indicating a lack of trend sensitivity. The design scheme tree and trend curve are subsequently utilized to effectively analyze the flow field characteristics of different schemes. Finally, the control parameter trend analysis method is employed to rank the design scheme tree and verify that the ranking of candidates is not dependent on the number of meshes. This paper investigates and verifies the presented system, method, and assumption and explores the possibility of an established system playing a more critical role in performance design work.
Tracking metal pollution from illegal gold mining: a health risk assessment in Edfu, Egypt
Authors: AbdelMaksoud Kholoud M. , Al-Metwaly Wael M. , Hathout Heba M. R.
Published: February 2025

Over the past decade, there has been an increase in small-scale gold mining in the arid southern region of Egypt. Miners extract ore from the Eastern Desert and transport it to Nile Valley farms, where ample water facilitates the processing. In Edfu, Egypt, the lack of economic opportunities prompted resource-constrained farmers to transform their agricultural lands into gold mines. The study utilized a multifaceted approach that integrated various methodologies, including remote sensing technologies, field surveys, chemical analyses, and statistical methods. The study aimed to assess the concentrations of carcinogenic agents and determine the potential human health risks associated with these agents in soil and fish samples collected within the city boundaries. The study examined correlations between various heavy metals (HMs), such as Ni, Pb, Cd, Cr, Cu, and Hg, in Soilsamples collected in 2020 and 2022. The results revealed direct proportional relationships among specific HMs. The Index of Geoaccumulation (Igeo) and Pollution Load Index (PLI) revealed significantly elevated values in both years, indicating potential environmental degradation. Although no carcinogenic hazards were identified, non-carcinogenic risks related to ingestion were observed for both adults and children exposed to mercury (Hg), copper (Cu), and arsenic (As). Contamination Factor (CF) values were also significantly high. Ecological risks were observed in both Soiland water, as well as in Nile Tilapia samples. Hazard Quotients (HQ) calculated for Nile Tilapia indicated potential risks for both adults and children, particularly associated with elevated arsenic (As) levels. This transformation elicited concerns regarding environmental and health implications, leading us to undertake a thorough investigation.
High-Precision computational solutions for nonlinear evolution models in graphene sheets
Authors: Khater Mostafa M. A. , Alfalqi Suleman H. , Vokhmintsev Aleksander
Published: February 2025

This study investigates the analytical solutions of a nonlinear evolution model governing the dynamics of graphene sheets, a material renowned for its exceptional electronic properties and versatile applications in nanotechnology. Three advanced analytical approaches-the Khater II (Khat II) method, the Khater III (Khat III) method, and the Generalized Rational (GRat) approach-are employed to derive exact solutions for this model with high precision. The accuracy and reliability of these solutions are validated by comparing them to numerical results obtained via He’s Variational Iteration (HVI) method, which serves as a benchmark for numerical verification. The analysis reveals a remarkable agreement between the analytical and numerical solutions, highlighting the robustness and effectiveness of the proposed methodologies. Furthermore, this study provides new insights into the nonlinear dynamics and physical properties of graphene sheets, while also identifying connections to other prominent nonlinear evolution equations. The innovative use of these analytical techniques offers practical frameworks for addressing complex nonlinear models in mathematical physics, thus advancing solution methodologies for such equations. This research contributes significantly to applied mathematics, material science, and nanotechnology by delivering accurate solutions and enhancing our understanding of graphene’s nonlinear behavior. Finally, the findings have far-reaching implications, offering potential applications in designing advanced materials with tailored properties to support technological advancements, thereby pushing the boundaries of nanotechnology and materials engineering.
Assessing hazard prediction and risk calibration skills in experienced and novice e-scooter riders
Authors: Ventsislavova Petya , Harrison Lydia , Baguley Thom
Published: February 2025

Less experienced e-scooter riders often exhibit risky riding behaviours. Despite this, no studies have examined how riders calibrate risk, respond to hazardous situations, and the impact of riding experience on these skills. To address this, this study assessed hazard prediction and risk calibration in e-scooter riders via bespoke video-based tests featuring real e-scooter footage filmed from the rider’s perspective. The first experiment assessed the ability of e-scooter riders to predict hazardous riding scenarios. The second experiment evaluated their proneness to engage in risky riding situations. The results indicated that increased riding experience did not improve riders’ hazard prediction skills or reduced their proneness to engage in risky riding. In fact, a higher riding frequency was linked to an increased tendency to engage in risky behaviour in certain scenarios. The results highlight that the typically short duration of e-scooter trips may limit riders’ exposure to a variety of hazards, hindering their ability to develop effective risk calibration skills. The observed high propensity to engage in risky riding scenarios, combined with average hazard prediction scores, emphasizes the need for targeted rider training focused on vigilance and risk awareness.
Exploring potential biomarkers for acute myocardial infarction by combining circadian rhythm gene expression and immune cell infiltration
Authors: Yu Xiao , Zhang Xiaopeng , Bilal Hazrat , Shi Chang , Sun Lei
Published: February 2025

Current diagnostic biomarkers for acute myocardial infarction (AMI), such as troponins, often lack specificity, leading to false positives under non-cardiac conditions. Recent studies have implicated circadian rhythm and immune infiltration in the pathogenesis of AMI. This study hypothesizes that analyzing the interplay between circadian rhythm-related gene expression and immune infiltration identify highly specific diagnostic biomarkers for AMI. Our results demonstrated differential expression of 15 circadian rhythm-related genes (CRGs) between AMI patients and healthy individuals, with five key genes—JUN, NAMPT, S100A8, SERPINA1, and VCAN identified as key contributors to this process. Functional enrichment analyses suggest these genes significantly influence cytokine and chemokine production in immune responses. Immune infiltration assessments using ssGSEA indicated elevated levels of neutrophils, macrophages, and eosinophils in AMI patients. Additionally, we identified potential therapeutic implications with 13 pivotal miRNAs and 10 candidate drugs targeting these genes. The Benjamini–Hochberg method was employed to adjust for multiple testing, and the results retained statistical significance. RT-qPCR analysis further confirmed the upregulation of these five genes under hypoxic conditions, compared to controls. Collectively, our findings highlight the critical role of CRGs in AMI, providing a foundation for improved diagnostic approaches and novel therapeutic targets.
Focal adhesion dynamics-mediated cell migration and proliferation on silica bead arrays
Authors: Park Yi-Seul , Choi Yerin , Lee Jin Seok
Published: February 2025

This study investigated the adhesion-mediated cell migration and proliferation of HeLa cells cultured on silica bead (SB) arrays with various nanotopographies, featuring the controllable adhesive area obtained by varying the curvature of SBs.
Uniform and size-tunable dasatinib nanoemulsions synthesized by a high-throughput microreactor for enhanced temperature stability
Authors: Wang Su , Li Chao , Zhang Jiaxiang , Ma Kaixuan , Zhang Wanyao , Gao Yan , Li Xue , Zhang Jingsheng , Guo Liang , Nie Yingying , Li Yuguang , Sun Ruiyan , Zhu Ning , He Wei , Zhao Shuangfei , Guo Kai
Published: February 2025

High-throughput microreactor-mediated synthesis of uniform dasatinib nanoemulsions with tunable particle sizes for enhanced temperature stability.
NaOH/urea aqueous solution facilitates spectroscopic quantitation of lignin in corn stalk
Authors: Yan Kexin , Li Nan , Tian Qifan , Tan Zijian , Qin Qingchen , Duan Jinao , Zhu Leilei , Liu Haifeng
Published: February 2025

A facile spectrometric determination of lignin in corn straw was constructed through dissolving the lignin–carbohydrate complex in aqueous solution at room temperature.
Heteropolyacids and ruthenium on covalent triazine frameworks – a bifunctional, recyclable catalyst for bio-based tandem systems
Authors: Hombach Lea , Müller Fabian , Varamo Fulvio , Ogolla Charles Otieno , Hoffmann Renée , Frohne Jonas , Schönherr Holger , Palkovits Regina , Butz Benjamin , Beine Anna Katharina
Published: February 2025

A recyclable catalytic system for the one-pot hydrolytic hydrogenation of xylan to xylitol has been developed.
Fabrication and characterization of phosphoinositide containing asymmetric vesicles in physiological salt conditions
Authors: Paratore Trevor A , Ross Alonzo H , Gericke Arne
Published: February 2025

Phosphoinositide (PIPs) lipids mediate a broad range of physiological functions by attracting proteins at specific time points to distinct cellular sites. Many of these processes are associated with the local...
Regioisomerism in NIR-II-emissive semiconducting biradicals for high-performance bioimaging and phototheranostics of tumors
Authors: Luo Yu , Liu Ying , Chen Wenbin , Gao Yijian , Kan Lijun , Chen Huan , Wang Yu , Li Mingde , Li Shengliang , Zhang Xiao-Hong
Published: February 2025

A regioisomerism of semiconducting biradicals provides enhanced NIR-II absorption and photothermal conversion capabilities and achieves high-resolution whole-body and tumor trimodal NIR-II imaging with high tissue penetration.
Engineering tri-channel orthogonal luminescence in a single nanoparticle for information encryption
Authors: Zheng Jianhao , Du Pengye , An Ran , Liang Yuan , Wei Yi , Liu Shuyu , Lei Pengpeng , Zhang Hongjie
Published: February 2025

Tri-channel orthogonal luminescence under different excitation wavelengths is achieved in a single nanoparticle for information encryption.
Photocatalytic selective disulfuration of aryl aldehydes and alkenyl aldehydes with dithiosulfonate as a bifunctional disulfur reagent and hydrogen atom acceptor
Authors: Jiao Jingchao , Xu Juan , Li Jingru , He Hongru , Yang Runliang , Ren Xiaorui , Gao Qianwen , Wang Xi
Published: February 2025

We developed a photocatalytic method for the selective disulfuration of aryl aldehydes and alkenyl aldehydes using a bifunctional dithiosulfonate (ArSO2-SSR), enabling the synthesis of benzoyl disulfides and chroman-4-ones with disulfide moieties.
Organic reactions catalyzed by the Brønsted acid B(C6F5)3·H2O
Authors: Liu Tianwei
Published: February 2025

This article reviews the organic reactions catalyzed by the Brønsted acid B(C6F5)3·H2O and their mechanisms, along with an outlook on its future catalytic prospects.
Anti-poisoning of CO and carbonyl species over Pd catalysts during the electrooxidation of ethylene glycol to glycolic acid at elevated current density
Authors: Cheng Jia , Tu Yunchuan , Xiang Yang , Ni Jingtian , Guo Tao , Huang Xun , Liu Bin , Wei Zidong
Published: February 2025

Incorporating Ni and Mo significantly boosts Pd-based catalysts' activity and durability in ethylene glycol electrochemical oxidation to glycolic acid, especially by enhancing CO poisoning resistance.
Controlled crystal orientation and reduced lattice distortion with a cystamine dihydrochloride spacer for efficient and stable 2D/3D perovskite solar cells
Authors: Liu Shunhui , Wang Xueying , Zhong Yang , Luo Xiao , Liu Yikun , Gao Binlou , Tan Licheng , Chen Yiwang
Published: February 2025

A novel spacer cation, cystamine dihydrochloride, is employed to build DJ 2D/3D perovskites. It regulates crystal orientation and reduces residual strain in perovskite. The champion device achieves an efficiency of 24.54% with excellent stability.
Natural Binders for Synchronous Management of Iodine Species Adsorption and Redox toward Sustainable Carbon-Based Perovskite Solar Cells
Authors: Ding Feifei , Zhou Huanyi , Chen Yan , Sang Kaihang , Tong zhensang , Wei Jianwu , Wu dongqi , zhang jiayu , He haixiang , Pang Qi , Chen Peican , Zhou Liya
Published: February 2025

Under illumination or heat conditions, iodine ions in perovskites are highly susceptible to oxidation into iodine molecules (I0). This can set off a chain reaction that accelerates perovskite degradation and...
Heterogeneous and microporous structure evolution of heated/radiated polyacrylonitrile fibers revealed by X-ray micro-computed tomography and scattering
Authors: Huang Yuhang , Shao Ruiqi , Tian Feng , Shi Haiting , Wang Gaohui , Wang Wei , Pei Xiaoyuan , Xue Yanling , Xu Zhiwei
Published: February 2025

Heat treatment, a critical pre-oxidation process, plays an essential role in the preparation of carbon fibers.
The influence of an acid additive on linear and branch selectivity in the C–H alkylation of N-pyridinecarbonyl-protected 2-methylbenzylamine with 1-heptene catalyzed by Rh2(OAc)4: a theoretical investigation
Authors: Han Lingli , Guan Fei , Chen Zifan , Xing Yaqian , Meng Zitong , Lv Kang , Liu Tao
Published: February 2025

The role of an acid additive and the origins of the reaction are clarified through our calculations.
Human activity recognition: A review of deep learning‐based methods
Authors: Dutta Sanjay Jyoti , Boongoen Tossapon , Zwiggelaar Reyer
Published: February 2025

Human Activity Recognition (HAR) covers methods for automatically identifying human activities from a stream of data. End‐users of HAR methods cover a range of sectors, including health, self‐care, amusement, safety and monitoring. In this survey, the authors provide a thorough overview of deep learning based and detailed analysis of work that was performed between 2018 and 2023 in a variety of fields related to HAR with a focus on device‐free solutions. It also presents the categorisation and taxonomy of the covered publication and an overview of publicly available datasets. To complete this review, the limitations of existing approaches and potential future research directions are discussed.
Structural optimisation of oil immersed transformer winding block washers based on WOA‐DRBF surrogate model optimisation strategy
Authors: Dong Yufei , Gao Chenglong , Xiang Wenxin , Liu Gang , Liu Yunpeng , Liu Yang , Du Zhenbin
Published: February 2025

In order to reduce the transformer winding hot spot temperature (HST), a dynamic radial basis function surrogate model optimisation strategy is proposed to optimise the structure of the forced oil circulation transformer winding's block washers in this paper. The whale optimisation algorithm (WOA) is introduced to obtain the optimal hyperparameter, and the WOA‐DRBF surrogate model optimisation strategy is used to improve the fitting and optimisation ability. After optimisation, the HST corresponding to the size of the block washers decreased by 3.67°C, and the maximal temperature rise decreased by 12.93%, effectively ameliorating the phenomenon of excessive local temperature rise within each partition. Comparing the above optimisation results with those of the WOA‐RBF static surrogate model and the genetic algorithm (GA), the proposed method shows superior performance in both optimisation search capability and efficiency. Comparing the optimisation efficiencies of the three methods, the number of model calls for the WOA‐DRBF method is 23.89% of the WOA‐RBF method and 1.77% of the GA method, respectively. The proposed method significantly enhances optimisation efficiency while improving global optimisation search capability. It offers a feasible solution for efficiently and accurately solving the optimisation problem of the transformer winding's block washer.
Effect of reversible plasticity of superconductors on their physical properties (a review)
Authors: Boiko V. S. , Kosevich A. M. , Kosevich Yu. A.
Published: February 2025

The existence of reversible plasticity of superconducting materials opens new possibilities of controlling their superconducting parameters with the help of external fields which may change the volume of the inclusions of the other phase and the total area of the boundaries. The reversible plasticity of traditional and high-temperature superconductors and its effect on their physical properties are analyzed. The reversible variation of the parameters of traditional superconductors under the action of elastic fields is studied, as well as the localized superconductivity of twin boundaries and the possible mechanisms of its realization, twin structure of high-temperature superconductors, effect of twin boundaries on the superconductivity of HTS materials, pinning at the boundaries, realization of the reversible plasticity of HTS materials and its possible mechanisms, and the reversible variation of parameters of HTS materials under the action of mechanical loads and magnetic fields.
Oscillatory motion in 3He-A and the participation of the superfluid component in diffusion modes
Authors: Kekutiya Sh. E. , Sanikidze D. G. , Chkhaidze N. D.
Published: February 2025

Diffusion vibrational modes are studied in superfluid 3He-A in zero magnetic field for different angles θ between the orbital axis I and the wave vector q. The dispersion relation for these modes is found to depend on the wave polarization. It is shown that in addition to the normal component velocity, the superfluid component velocity also oscillates in the diffusion modes of 3He-A. The frictional forces due to viscous waves in 3He-A, exerted in the plane surface which is in contact with a superfluid liquid layer of finite thickness and performs a simple harmonic oscillatory motion, are calculated. It is found that the frictional force has not only parallel, but also a perpendicular component relative to the plane of oscillations.
Temperature anomalies in the impedance and heat capacity of yttrium ceramics at T ≳ T
c
Authors: Dmitriev V. M. , Eropkin V. N. , Gurevich A. M. , Isakina A. P. , Ofitserov M. N. , Prentslau N. N. , Prokhvatilov A. I.
Published: February 2025

Correlating anomalies in the rf impedance and the heat capacity of single-phase YBa2Cu3O6.8 ceramic are observed for the same sample in the temperature intervals 82–85, 92–95, 155–165, 180–240, and 260–290 K. The anomalies are manifested in the form of peaks and valleys on the temperature dependences of these quantities as well as in hysteresis effects. The nature of the observed peculiarities is discussed.
Oxygen concentration in intergranular layers and superconductivity of YBa2Cu3Ox metaloxide ceramics
Authors: Ivanchenko Yu. M. , Mikheenko P. N.
Published: February 2025

A diamagnetic study is carried out for YBa2Cu3Ox metal oxide ceramic subjected to deoxidation (followed by quenching) at different temperatures from 300 to 900 °C. A method of determining the oxygen concentration in granules and intergranular layers of the metaloxide is developed. It is found that oxygen-depleted N-interlayers are responsible for the degradation of superconducting properties of Josephson junctions of the S–I–N–S type formed during deoxidation. The possibility of decreasing the critical temperature of intergranular layers by varying the properties of insulating (I) interlayer is considered. The value of oxygen deficiency in intergranular layers of the ceramic relative to oxygen content in the bulk of granules is restored for the entire practically important temperature interval of metaloxide quenching. The physical principles of an analysis of the family of temperature dependences of diamagnetic response in bulk superconducting materials are considered.
Influence of defects on the motion of the phase boundary in dysprosium orthoferrite
Authors: Chizhik A. B. , Gnatchenko S. L. , Kharchenko N. F.
Published: February 2025

The theory of thermally activated motion of domain walls is used to consider the influence of crystal defects on the dynamics of phase boundaries (PB) in dysprosium orthoferrite. A comparison of the experimental and theoretical data shows that the defects are responsible for an exponential dependence of the velocity of PB on the magnetic field strength. The field dependence of the velocity of continuous motion of PB between defects is separated, and a good agreement is observed between this dependence and the dependence V(H) calculated within the framework of the theory, taking into account the transformation of DB in a magnetic field.
Effect of heat removal on avalanche crystallization of amorphous metals
Authors: Kuz’menko V. M. , Shklovskii V. A. , Vladychkin A. N.
Published: February 2025

The dependence of the rate of propagation of the avalanche (explosive) crystallization front on the thickness of amorphous bismuth films is studied. It is shown that avalanche crystallization cannot take place in amorphous films of ytterbium and bismuth on metal substrates. The obtained results are explained in the framework of the modern theory.
Volume dependence of thermal pressure in solidified noble gases
Authors: Yakub L. N.
Published: February 2025

The volume dependence of the derivative (∂P/∂T)V for solidified noble gases is investigated on isotherms, melting and sublimation curves. Theoretical predictions are compared with the experimental results for solid xenon. The value of (∂P/∂T)V is found to decrease with increasing volume and temperature.
Excited state of muonium atom in condensed nitrogen
Authors: Grebinnik V. G. , Duginov V. N. , Zhukov V. A. , Kirillov B. F. , Lazarev A. B. , Pirogov A. V. , Storchak V. G. , Shilov S. N.
Published: February 2025

The dependence of the initial phase of muon precession of the magnitude of the transverse magnetic field is measured in order to determine the state of the short-lived muonium in condensed nitrogen. It is found that muonium exists in an excited state in nitrogen.
The effect of impurities on the planar structure of a spin chain with a Dzyaloshinskii interaction
Authors: Zvyagin A. A.
Published: February 2025

The effect of impurities on the planar spin structure of a spin chain with a Dzyaloshinskii-type interaction is investigated theoretically.
Photoelectric enhancement in degenerate semiconductor–HTS–insulator–metal tunnel structure
Authors: Alfeev V. N. , Men’shov V. N. , Neustroev L. N.
Published: February 2025

The quasiparticle photoelectric current emerging in the semiconductor–high-temperature superconductor–insulator–metal tunnel structure as a result of absorption of light in the superconductor is investigated. It is shown that a considerable photoelectric enhancement is possible in such a structure.
Coherent charge fluctuations in Josephson junctions and effective capacitance oscillations
Authors: Krive I. V. , Rozhavskii A. S.
Published: February 2025

A new effect of macroscopic coherent 2e-charge fluctuations leading to voltage oscillations of the effective capacitance is predicted for small Josephson junctions. The oscillation period is Vc = 2e/C (C is the total capacitance of the junction), and the oscillation amplitude decreases rapidly with increasing temperature as exp (−π2T/Ec), where Ec = (2e)2/2C.
Subharmonics of energy gap in superconducting channels under non-Josephson generation
Authors: Churilov G. E. , Dikin D. A. , Dmitriev V. M. , Svetlov V. N.
Published: February 2025

A subharmonic structure of the energy gap in a superconducting channel is experimentally detected on the first derivative of the I–V curve for voltages lower than 2Δ/e. The dependence of the variation of subharmonic features on temperature, power, and frequency of the external radiation leads to the conclusion that the phase slip center displays the properties of the SNS structure under high voltages. At certain temperatures, a dip appears against the background of the subharmonic peak, and this is followed by the initiation of a non-Josephson generations in the sample. Measurements of the external signal reflected from the sample over a wide frequency range reveal that, during the generation, an internal resonance exists in the film at the generation frequency.
Kinetic characteristics of high-T
c thallium superconductors
Authors: Shchetkin I. S. , Osmanov T. Sh. , Abramov N. V. , Evseev V. Z.
Published: February 2025

The results of investigations of the temperature dependence of electrical resistance and thermo-emf of thallium based high-Tc superconductors Tl2BaCa2Cu3Ox, TlBaCaCu3Ox, and Tl4Ba2Ca3Cu4Ox are presented.
Reversible recovery of excess current in Y(Ho)–Ba–Cu–O–normal metal point contacts under high voltages
Authors: Rybal’chenko L. F. , Fisun V. V. , Bobrov N. L. , Yanson I. K. , Bondarenko A. V. , Obolenskii M. A.
Published: February 2025

A polarity-dependent reversible change in the current–voltage characteristics between states corresponding to different values of the excess current Iexc is observed for bias voltages of several hundred millivolts in Ag-ReBa2Cu3O7–x (Re = Y, Ho) point contacts in the current–carrying state. The observed effect has a high intensity (right up to a complete suppression or recovery of Iexc) and is not accompanied by a noticeable variation of the energy gap or the critical temperature in the point contact region. It is also established that the states with intermediate values of Iexc are stable for zero bias voltages across the point contacts, at least up to 110 K. It is assumed that the variation of Iexc and the coresponding modification of IVC are due to the oxygen migration processes induced by the electric field and current, resulting in a local variation of the superconducting parameters in the point-contact region.
Nonequilibrium phonon relaxation in beryllium point contacts
Authors: Balkashin O. P. , Yanson I. K. , Pilipenko Yu. A.
Published: February 2025

The frequency dispersion of the background component in Be point-contact spectra is studied. The frequency of the electron–phonon relaxation at Debye energies is found to be 3·1010 Hz. Possible reasons behind residual background are analyzed as well as the improvement of rf resolution of point-contact spectroscopy.
Superfluidity in a suppressing field: asymptotic behavior and characteristic lengths
Authors: Kiknadze L. V. , Mamaladze Yu. G.
Published: February 2025

A unified approach is used for analyzing the density distribution of the superfluid component in liquid helium in various magnetic fields suppressing superfluidity. The asymptotic behavior in superfluid and normal regions is considered as well as various characteristic lengths determining the variety of spatial distributions under investigation.
Analysis of the electron structure of YBa2Cu3O7−xFx (x = 0, 1, 2) films
Authors: Dubrovskii O. I. , Kurganskii S. I. , Domashevskaya E. P.
Published: February 2025

The electronic energy spectrum of thin films of YBa2Cu3O7−x Fx (x = 0, 1, 2) is investigated by using the linearized augmented plane wave method. Total and partial densities of electron states (DES) are calculated for each film. The substitution of F atoms for the oxygen atoms in the Ba-O layer in a unit cell of the film leads to an increase in the DES value at the Fermi level and to a change in the form of local DES for Cu and O atoms. The O→F substitution in the layer formed by one-dimensional Cu–O chains practically does not affect the electronic structure.
Proximity effect in superlattices
Authors: Gvozdikov V. M. , Teixeira M.
Published: February 2025

The spatial dependence of the superconductor order parameter in a superlattice formed by alternating layers of two types of normal metals in contact with a bulk superconductor is studied in terms of the Ginzburg–Landau theory by using the method of transfer matrix. It is found that the exponent is proportional to a discrete variable Ls = bn rather than to the total distance L = (b + d)n to the SN boundary, where n is the number of superlattice periods counted for the SN boundary. This is due to the fact that in the superlattice model under consideration, the interlayers are homogeneous films of a nonsuperconducting metal of thickness d. In contrast to interlayers, the normal layers (which are also metal films of thickness b of the order of the coherence length) may go over to the superconducting state at a temperature slightly lower than the critical temperature of the bulk superconductor.
Nonlinear magnetoresistance of compensated metals
Authors: Peschanskii V. G. , Oyamada K. , Stepanenko D. I.
Published: February 2025

Nonlinear dynamic effects in the electrical conductivity of compensated metals in a constant magnetic field H0 are investigated theoretically. The current distribution over the cross section of a plate is analyzed for different angles θ between the current density j and the vector H0 parallel to the plate faces. It is shown that with increasing j the quadratic increase in the resistivity ρ with H0 will be replaced by a considerably weaker dependence of ρ on H0. The domain of H0 and θ in which the nature of conductivity changes, due to the expulsion of the current to the sample surface with increasing H0 even under nonlinear conditions, is determined.