bluuebunny/crossref_metadata_2025 huggingface dataset:
Passivity theorems for input-to-state stability of forced Lur'e inclusions and equations, and consequent entrainment-type properties
Authors: Guiver Chris
Published: January 2025

A suite of input-to-state stability results are presented for a class of forced differential inclusions, so-called Lur'e inclusions. As a consequence, semi-global incremental input-to-state stability results for systems of forced Lur'e differential equations are derived. The results are in the spirit of the passivity theorem from control theory as both the linear and nonlinear components of the Lur'e inclusion (or equation) are assumed to satisfy passivity-type conditions. These results provide a basis for the analysis of forced Lur'e differential equations subject to (almost) periodic forcing terms and, roughly speaking, ensure the existence and attractivity of (almost) periodic state- and output-responses, comprising another focus of the present work. One ultimate aim of the study is to provide a robust and rigorous theoretical foundation for a well-defined and tractable ``frequency response'' of forced Lur'e systems.
GIS-Driven mineral exploration: Enhancing geological insight through aeromagnetic integration
Authors: Benyas Kawtar , Idrissi Assia , Qarbous Abdelmounim , Sassioui Slimane , Aarab Abdellatif , Lakhloufi Abdellah , Aitali Rajaa
Published: January 2025

The Rehamna Variscan massif, located in the western Moroccan Meseta, is known for its geological complexity and mining potential, requiring detailed investigation to uncover its hidden resources. This study combines spatial analysis with aeromagnetic geophysical prospecting methods, using Geographic Information Systems (GIS), which are effective for integrating spatio-temporal data and organizing research phases. The goal is to demonstrate that incorporating aeromagnetic data into GIS enhances the detection and analysis of geological structures, thus facilitating mineral prospecting. This integration identified a significant bipolar magnetic anomaly, similar to that of the Hajjar mine, indicating favorable geological structures for mineralization. It also helped map faults and other geological discontinuities, revealing new target areas for in-depth mineral exploration, particularly for precious metals. The findings highlight the effectiveness of GIS in mineral prospecting in geologically complex regions. However, interpreting the data requires expertise in geophysics and geology to improve model accuracy. This combined approach allows for more precise analysis and better planning of mining exploration efforts.
Identification of Suitable Sites for Rainwater Harvesting Using AHP and GIS in the Middle and High Moulouya Basin, Morocco
Authors: Amiri Mustapha , Bouguelba Smail , Sbai Abdelkader , Ghzal Mohamed , Qadem Zohair , Salem Ali
Published: January 2025

Several researchers have utilized various methodological frameworks to determine appropriate locations and methodologies for Runoff Water Harvesting (RWH) in semi-arid and arid area. This plays a crucial role in addressing water scarcity during dry periods. Establishing RWH sites within basins to collect rainwater from small basin and facilitate artificial groundwater replenishment is a viable solution to mitigate water deficiencies in the middle and upper Moulouya basin. In this study, a methodology integrating remote sensing data and geographic information systems was developed based on a model created in SIG software. Seven factors including lithology, climate, land cover/land use, digital elevation, recharge, and surface runoff. Were employed to assess the suitability of sites for RWH. The resulting spatial distribution of the suitability map categorized the basin into five classes of RWH potential, ranging from very high to very low suitability. These findings offer significant promise in terms of identifying suitable sites for RWH. The RWH suitability map revealed that within the Moulouya basin, areas were classified into unsuitable (20.15%), less suitable (40.82%), moderately suitable (24.38%), well-suited (9.60%), and highly suitable (5.02%) categories for RWH. This final map serves as a valuable resource for decision-makers, hydrologists, and urban planners, offering crucial guidance for future water resource and land management initiatives by swiftly pinpointing areas with the highest potential for rainwater harvesting.
Development of an Importance Scale for Seawater Intake Types Based on Physical Parameters Database
Authors: El Masmodi Rim , El Mansouri Bouabid
Published: January 2025

This article presents an advanced Geographic Information Systems (GIS) based interface that innovates coastal water resource management in Morocco, with specific application to the ASSILAH region. This solution integrates spatial analysis with multi-criteria decision support, particularly focusing on the geographical distribution and territorial challenges of the Moroccan coastline, using programming tools such as Excel Visual Basic for Applications (VBA). The methodology combines GIS spatial analysis capabilities with the Analytic Hierarchy Process (AHP) to evaluate complex geographical parameters including bathymetry and coastal infrastructure. The integration of geospatial data provides a clear and precise visualization of potential areas for seawater intake installations, thereby facilitating the understanding of territorial issues for decision-makers. The AHP method, known for its robustness in multi-criteria decision support, allows for choosing the optimal type of seawater intake. The interface, developed through Excel and VBA, transforms complex spatial and analytical data into an accessible decision support tool. The resulting system offers regional planners a comprehensive framework for coastal sustainable infrastructure development in the Assilah coastal region as a pilot case for Morocco's unique geographical context.
Using the phantom 4 RTK drone for photogrammetry to create topographic plan of road
Authors: El Atiq Jaouad , El Harti Abderrazak
Published: January 2025

Drone photogrammetry is a swift, inexpensive, accurate, and detailed procedure that makes it possible to obtain pictures for the creation of a high spatial resolution Digital Terrain Model (DTM) with enhanced planimetric and altimetric precision. It also provides the possibility of cartographic land use. Study site: the experiment was carried out in a mountain area using a Phantom 4 RTK drone over the road connecting Demnate to Aït Bouguemez in the province of Azilal. The results were processed with Agisoft software running a TIN (Triangulated Irregular Network) based algorithm for a geometric classification (ground vs above ground). This was followed by manual intervention to increase the accuracy of the desired output. Image processing and classification helped to build a Digital Terrain Model with an altimetric RMSE of 5 cm - just 3 cm for planimetric error. This extreme accuracy is valuable when performing tasks that demand great precision, like building a detailed road development plan.Drone photogrammetry excels in the development of roads, highway, and many other tasks mainly thanks to its speed, cost-effectiveness and detail. In this paper, the results show that this technique produces high- fidelity images and can make a DTM with high precision. This higher accuracy leads to informed decisions in the planning and implementation of road work.
Use of the LCM Model in the prospective simulation of land use in the Nafoun watershed (Northern Ivory Coast)
Authors: Kamagate Anzoumanan , Koffi Ehouman Serge , Koffi Yao Blaise
Published: January 2025

Land use change is known worldwide as a driver of environmental change. Environmental change assessment is the most accurate method for understanding land use, the types of change to be estimated, and the forces and evolutions driving these changes. The aim of the study is to assess the temporal and spatial dynamics of land use change and to predict the future using Landsat images. The Land Change Modeler (LCM) was therefore used. LCM is a module integrated into a Geographic Information System (GIS) and TerrSet geospatial modeling system, assimilated to the Multi- Layer Perceptron (MLP) and the CA_Markov chain for analysis and prediction of land use change and assessment of environmental implications. LCM forward modeling relies on two types of input maps: (1) land cover maps at previous times and (2) explanatory variable maps. Our study area is the Nafoun watershed in the Poro region of northern Côte d'Ivoire. Landsat images from 1986, 2000 and 2023 were used to assess and predict the spatio- temporal distributions of land use change. The historical results show that from 1986 to 2023, two trends were observed in the evolution of the different land cover classes in the Nafoun watershed. The first trend is regressive and concerns forests, savannahs, water and habitats/bare ground. The second trend is progressive and concerns crops, whose surface area has practically increased tenfold, from 8.31 to 78.15 km2. The land-use map of the Nafoun watershed to 2070 in the deforestation scenario shows a trend towards an increase in agricultural areas and bare habitats/soils, and a decrease in savannah, forest and water areas. However, in the reforestation scenario, the forest and savannah class have increased significantly, while the area of habitats/bare ground has decreased. In this scenario, a sound environmental protection policy would play a positive role in the conservation of natural plant resources.
Numerical and experimental investigations on a hybrid vertical axis wind turbine
Authors: Budea Sanda , Simionescu Ștefan-Mugur , Copăceanu Valentin
Published: January 2025

Wind energy represents one of the main sources of renewable energies. Innovation in wind turbine technology tends to focus on increasing energy production, especially at low wind velocities. Vertical axis wind turbines could have a greater expansion because they have many advantages, such as the capacity to start at low wind velocities and no need for orientation to the wind direction. The present paper analyses numerically and experimentally, a Savonius-Darrieus hybrid wind system on a common vertical shaft. CFD modeling and simulation show a slight instability at low velocities, up to entering the nominal working regime of 2-3 m/s, but also the separation of vortices and the fluid-blade interaction at over 9 m/s. At higher velocities, the performances and the power coefficients decrease, observations demonstrated also experimentally within the study. The optimal wind velocity for the Savonius-Darrieus vertical turbine is 6 m/s.
Optimizing building performance with Digital Twins: Pathways to energy efficiency and decarbonization
Authors: Tanase Andra , Croitoru Cristiana
Published: January 2025

In the context of current energy consumption and CO2 emissions, the impact of buildings is highly significant. In the quest for sustainable building management, the concept of digital twins emerges as a transformative technology, offering unprecedented capabilities for enhancing energy efficiency and reducing carbon footprints. This article explores the application of digital twins in the built environment, emphasizing their role in achieving significant energy and environmental benefits. Beginning with a brief discussion introducing the concept of digital twins, the article highlights their critical importance in modern building management and their potential to revolutionize sustainability practices. It then examines the role of IoT and AI in enabling advanced aspects of digital twin technology, including its technological functionalities. A comparative analysis of different simulation tools and methodologies follows, providing a comprehensive overview of how digital twins can be utilized to optimize building performance.
Enhancing the performance of a heating, ventilation, and air conditioning system using ice slurry
Authors: Iakabos Emil , Danca Paul , Chiriac Florea , Ilie Anica , Girip Alina , Nichita Madalina Teodora
Published: January 2025

This article examines the impact of different ice-slurry fractions on the cooling performance of an HVAC system. The findings reveal that increasing the ice percentage in the ice-slurry solution leads to a proportional enhancement in the system’s cooling capacity. This demonstrates the effectiveness of higher ice concentrations in improving cooling performance. This phenomenon could be particularly advantageous in designing cooling systems, enabling adjustments in ice concentration to optimize thermal efficiency based on specific requirements.
Development of an experimental setup for propeller performance measurements
Authors: Pugna Andreea , Hrab Călin , Hînsa Liviu-Nicolae , Hopârtean Andrei , Giurgea Corina-Maria , Marcu Lucian
Published: January 2025

With the increasing demand for efficient and adaptable unmanned aerial vehicles (UAVs), optimizing propeller performance has become essential to enhancing energy efficiency and thrust. This study introduces a compact, cost-effective experimental setup designed specifically for testing drone propellers on a small scale, making it accessible for both research and educational applications. The setup integrates off-the-shelf components, including a brushless motor controlled by an electronic speed controller (ESC), a load cell for precise thrust measurement, and a custom-built current sensor for power consumption analysis. The experimental set-up enables real-time data acquisition and evaluation of propeller performance across various operating speeds. By testing two commercial propellers—a two-blade and a three-blade design—the setup demonstrates its ability to analyze thrust and efficiency trends effectively. This innovative framework bridges the gap between theoretical studies and practical UAV applications, providing a versatile and scalable platform for advancing UAV propulsion research.
Exploring dilemma games in sustainable urban planning: A Cypriot case study on urban rooftop utilization for climate change
Authors: Merry Anna , Zachariou Aravella , Yau Jane
Published: January 2025

This paper describes the initial stages of a Cypriot case study on urban rooftop utilization for climate change, indicating how games can: foster collaboration; engage citizens; and produce policy incentives through real-world exploration and implications. The focus of the case study is a co-designed serious game developed within the context of the GREAT project (Games Realizing Effective and Affective Transformation) to be utilized as a facilitation tool between citizens and policy makers. Through learning and role-play scenarios, target groups can: voice their attitudes towards climate policies; gain valuable insights into specific initiatives; and enhance their acceptance of green infrastructure and sustainable urban planning. In this paper, we describe the initial co-design stages of the dilemma game, discuss the lessons learned, and provide future directions for research.
Citizen science for monitoring rainfall in Vietnam
Authors: Tran Huan N. , Duwal Sudeep , Prajapati Rajaram , Davids Jeffrey C. , Nguyen Dung T. , Miegel Konrad
Published: January 2025

Citizen Science (CS) has been arising as a promising approach to address hydro-meteorological data gaps spatially and temporally and providing information about catchment characteristics for water resource management for the last ten years. In Vietnam, many national efforts aimed to renovate and extend the operating water monitoring networks. However, the lack of reliable hydro-meteorological data remains an issue that may be better handled by using a CS approach. This study examines the CS approach to monitor rainfall in the Bui River Basin in Vietnam using low-cost rain gauges constructed from soda bottles, concrete, and rulers. The rainfall data of 19 citizen scientists from January 2022 to August 2023 were used for the analysis. The CS data were compared with data from one official reference station. The correlation coefficient (R) was applied to evaluate the significance of the agreement between the monthly CS data at the station with the longest measurement period and reference data. Results yield a significant correlation between CS and reference station with an R = 0,90. The results show that citizen science has the potential of being a complementary approach for existing Vietnamese monitoring systems, particularly for data-scarce areas.
Elimination of metoclopramid by the adsorption process (GAC) and ozone process
Authors: Oussama Khemis , Gabriel Racovițeanu , Elena Vulpașu
Published: January 2025

Existence of pharmaceutical substances in water with different concentrations in natural ecosystems it poses a danger to humans and animals.

Conventional methods for water treatment have proven to be relatively ineffective in removing pharmaceutical contaminants, while the more effective process used for our research to eliminate pharmaceutical substance metoclopramid are ozone processes and adsorption process.

This study investigated the reduction of a pharmaceutical substance metoclopramid during two simultaneous processes (ozone process and adsorption process) applied in a large-scale drinking water treatment pilot with two different EBCTs (3 minutes and 6 minutes), and the initial concentrations used were 1.6 mg/l, 0.8 mg/l, and 0.4 mg/l. we chose ozonation, which produces many hydroxyl radicals to decompose the pharmaceutical substance metoclopramide to eliminate it, and for the adsorption process, we chose granular activated carbon with a high capacity for adsorption.
The Romanian coastal area and green transport infrastructure
Authors: Nică Flaviu Ioan
Published: January 2025

The first part of the paper presents the local transport infrastructure conditions of the Romanian Coastal Area. The Coastal Area, from the geographical point of view is located on the East and South - East of the country, being part of South – East Development Region. It is aggregated mainly in two counties, Tulcea, where is found the intersection of Danube with Black Sea in Danube Delta and, Constanta where is the entire Romanian Black Sea shoreline. The first part also presents the steps that are already made by Romanian authorities to ensure the sustainability and reduce the pollution by increasing the green transport infrastructure. The second part of the paper presents the analysis of the transport system in the region together with the supporting data, and the challenges that puts pressure on our coastal area. Finaly, the aim is to come with solutions in order to increase sustainability, climate resilience, and to reduce the vulnerability on our coastal area with the purpose of multiplying and creating a good practice example for the entire community.
Tibial Plateau Angle Changes following Repair of Salter–Harris Type 1 and 2 Fractures in Dogs
Authors: Turner Abigail , Joffe Michelle R. , Davis Conor , Baron Sophie , Meyerowitz-Katz Gideon , Levien Andrew S.
Published: January 2025

Objective To determine (1) whether the tibial plateau angle (TPA) in dogs with Salter–Harris type 1 (SH-1) or type 2 (SH-2) fractures of the proximal tibial physis significantly decreases in the time between diagnosis and reevaluation following surgical repair and (2) whether the method of surgical repair influences the change in TPA over time.

Study Design This study was a retrospective study. Medical records from 2017 to 2022 were reviewed to identify dogs with SH-1 or SH-2 fractures of the proximal tibial physis that had undergone surgical repair with Kirschner wires (K-wires), with or without a tibial tuberosity tension band. The TPA of the affected limb was measured by four investigators on radiographs taken prior to surgery, immediately postoperatively and at 4–8 weeks follow-up, with the average values recorded.

Results A total of 32 dogs, 22 fractures repaired with K-wires and a tension band, and 10 with K-wires only. There was a mean decrease in TPA from injury to first reevaluation of 5.89 degrees (p < 0.001) and from immediately postoperatively to first reevaluation of 2.2 degrees (p = 0.018); however, no significant decrease in TPA was observed when comparing fractures repaired with or without a tension band.

Conclusion The TPA of dogs with SH-1 and SH-2 fractures of the proximal tibial physis decreased in the reevaluation interim following repair with K-wires with or without a tension band. Despite initial imperfect reduction, the risk of cranial cruciate ligament rupture may not be increased, potentially reducing the need for additional surgery if high TPA is observed postoperatively. This study was overrepresented by small breeds, and future studies on large and giant breeds with extended follow-up would be indicated.
Energy-demanding Redox Transformations via Electrophotocatalysis
Authors: Kang Wen-Jie , Tung Chen-Ho , Wu Li-Zhu
Published: January 2025

Electrocatalysis and photocatalysis are two widely recognized approaches to organic synthesis. Over the past decades, these strategies, leveraging distinct energy sources (electricity or light), have demonstrated remarkable capabilities in facilitating chemical transformations. Integrating the broad reactivity of photochemistry with the high chemoselectivity of electrochemistry, the recent advent of electrophotocatalysis has garnered increasing attention. This innovative approach is poised to revolutionize organic synthesis by capitalizing on their synergistic benefits. This Short Review aims to encapsulate the recent advancements in electrophotocatalytic energy-demanding redox transformations. These include, but are not limited to, C–H functionalization, C–X functionalization, and C=X functionalization, highlighting the potential of electrophotocatalysis to enhance the efficiency and selectivity of organic synthesis processes.
Comparative Evaluation of (18F)AlF-PSMA-HBED-CC and 68Ga-PSMA-HBED-CC in Staging Intermediate-/High-Risk Prostate Cancer: A Prospective Study
Authors: dos Santos Loureiro Gerardo Gabriel , Duarte Couto Pablo , Gambini Gonzalez Juan Pablo , Alonso Nuñez Omar
Published: January 2025

Objectives 68Ga-PSMA-HBED-CC positron emission tomography (PET)/computed tomography (CT) represents a clinically relevant technique for the evaluation of prostate cancer (PCa) patients, whereas 18F-AIF-PSMA-HBED-CC is a novel tracer produced in our center, with suitable radiochemical purity for clinical purposes. We prospectively compared the diagnostic values of both tracers for the detection of metastatic disease in patients with intermediate-/high-risk PCa at initial staging.

Materials and Methods Sixty-six patients (mean age: 63 years; range: 52–78 years) with PCa at initial staging (Gleason score ≥6; median prostate-specific antigen [PSA]: 10 ng/mL; range:1.7–152 ng/mL) prospectively underwent routine 68Ga-PSMA-11 and 18F-AlF-PSMA-11 PET/CT scanning with a 64-slice PET/CT scan with time-of-flight (TOF) correction. We measured the maximum standardized uptake value (SUVmax) and lesion-to-background ratio (LBR) in all coincidentally detected lesions. Open prostatectomy and pelvic lymph node dissection were performed in nonmetastatic patients. Histopathology, correlative imaging, and/or clinical follow-up were considered the gold standard. Follow-up was conducted at least 4 months after PET/CT scanning (median: 6.4 months; range: 4–11 months). Sensitivity, specificity, and predictive values were calculated.

Results The overall detection rate was 85% (56/66) for both tracers. At least one suspicious lesion indicating potential PCa metastasis was detected in 20 (30%) and 21 (32%) of 66 patients for 68Ga-PSMA-11 and 18F-AIF-PSMA-11 tracers, respectively. A total of 145 extra-prostatic lesions were detected in the bone (n = 56), lymph nodes (n = 88), and lung (n = 1) by at least one radiopharmaceutical: 131 (90%) for 68Ga-PSMA-11 and 123 (85%) for 18F-AlF-PSMA-11.

In concordant lesions, a significant correlation was found between the SUVmax of both tracers (r = 0.90, p = 0.001). The SUVmax and LBR for 18F-AlF-PSMA-11 were higher in bone foci (n = 39) compared with 68Ga-PSMA-11 (7.2 vs. 8.9 and 14 vs. 13, respectively, p = 0.02).

For the detection of systemic metastasis, the sensitivity values were the same for both techniques: 0.90 (95% confidence interval [CI]: 0.68–0.98). We calculated specificities of 0.96 (95% CI: 0.85–0.99) and 0.94 (95% CI: 0.82–0.98) for 68Ga-PSMA-11 and 18F-AlF-PSMA-11, respectively.

Conclusions 68Ga-PSMA-11 and 18F-AlF-PSMA-11 PET/CT seem to be clinically equivalent imaging techniques for the assessment of primary intermediate-/high-risk PCa with promising potential for the detection of metastatic spread that would impact patient management.
The impact of political, financial, and economic risks on energy transition: the role of natural resource rents
Authors: Wang Qiang , Li Xueting , Li Rongrong
Published: January 2025

The global emphasis on energy transition arises from the recognition of fossil fuel reliance exacerbating environmental degradation. The transition to cleaner, renewable energy sources stands central in mitigating climate change and promoting sustainability. This paper explores the influence of country risks, particularly political, financial, and economic, on energy transition while considering the role of natural resource rents. Using data spanning 88 countries from 2006 to 2020, categorized by income levels, the analysis reveals distinct patterns. Low political and financial risks exhibit a negative correlation with energy transition, while low economic risks display a positive association. The study identifies threshold effects: higher resource rents worsen the negative impact of low political and financial risks and weaken the positive effects of low economic risk on energy transition. These relationships differ among countries with different income levels. These insights highlight the nuanced interplay between country risks, natural resource rents, and the trajectory of the energy transition, crucial for steering societies toward sustainable development pathways.
Equations for the order parameter of a superfluid Fermi liquid with triplet pairing near T
c in magnetic field
Authors: Tarasov A. N.
Published: January 2025

The equilibrium properties of the superfluid 3He phases in a magnetic field are described for temperatures close to the phase transition temperature Tc from the normal to superfluid state. Landau’s Fermi-liquid approach, generalized to superfluid Fermi liquids (SFL), is employed. Equations are derived for the order parameter (OP) of an electrically neutral paramagnetic SFL with triplet pairing in a moderately high (MH) uniform magnetic field without account of strong-coupling effects. In the general case of triplet pairing (spin of the pair, s = l; orbital momentum of the pair, l, is an arbitrary odd number), an integral-differential equation has been derived, which is valid for small spatial inhomogeneities in SFL in the presence of de magnetic fields and at temperatures close to Tc. For the case of triplet pairing, the Ginzburg-Landau (GL) equation for the OP Aαj (complex-valued rank-3 matrix) has been derived. The corrections to the coefficients in the GL equation are found as a result of a perturbative account of the effect of the MH magnetic field and the Fermi-liquid interaction. In such fields, these corrections can be comparable with and even exceed the so called “nontrivial” strong-coupling corrections to the coefficients in the GL equation as well as exceed by far the contribution due to the particle-hole asymmetry in the distribution of quasi-particles. The corrections that are due to deformations of the OP in MH magnetic fields are important for the description of 3He–B at low pressures.
Continual description of vortices in He II at low rotational velocities
Authors: Kiknadze L. V. , Mamaladze Yu. G.
Published: January 2025

The continual description of rotating He II is used for deriving a relatively simple formula for the critical rate of formation of first vortices in the annular gap between two cylinders. A paradoxical situation emerging in a freely rotating vessel during the He I-He II phase transition followed by fast cooling is considered.
Influence of magnetic structure distortions induced by Cu2+ impurity ions on the transport properties of excitons in the quasi-one-dimensional antiferromagnet CsMnCI3·2H2O
Authors: Karachevtsev V. A. , Slavin V. V. , Shapiro V. V.
Published: January 2025

The characteristics of low-temperature exciton luminescence in the quasi-one-dimensional antiferromagnet CsMnCl3·2H2O doped with various concentrations of Cu2+ impurity ions are investigated. The quasi-one-dimensional migration of optical excitations in the vicinity of an impurity is observed as a result of the spin block being eliminated by distortion of the magnetic structure.
Magnetoelectric effects in spatially inhomogeneous magnetized 2D electron systems
Authors: Shikin V. B.
Published: January 2025

Local magnetoelectric perturbations of the electron density in heterogeneous 2D electron systems are considered in detail in the regions where the local filling factor assumes integral values. The contribution of these perturbations to the magnetocapacitance of the 2D electron band is determined. The possibility of spatial homogeneity violation is indicated for a problem of the magnetocapacitance of a parallel-plate capacitor formed by the 2D system and a screening electrode.
Anisotropy of point-contact characteristics of URu2Si2 in the normal state
Authors: Naidyuk Yu. G. , Kvitnitskaya O. E. , Yanson I. K. , Nowack A. , Menovsky A. A.
Published: January 2025

Differential resistance dV/dI(V) of point contacts based on the heavy-fermion compound (HFC) URu2Si2 is measured in the temperature range 1.5–20 K along two principal crystallographic directions. A distinguishing feature of dV/dI(V) measured below the Néel temperature TN = 17.5 K for URu2Si2 point contacts is a peak located asymmetrically with respect to zero voltage (V = 0). On the symmetric part of the dependence dV/dI(V) for homojunctions, such a peak is observed for currents directed at right angles to the c-axis, while the peak is suppressed or missing along the c-axis. The existence of such a peak is associated with anisotropic energy gap in the ab-plane, which is attributed to the spin-density waves (SDW) and appears on a part of the Fermi surface at temperatures below TN. The magnitude of the gap, estimated from the width of the peak in the symmetric part of dV/dI(V) for V = 0, was found to be equal to 10±l mV. The reproducible asymmetry of the differential resistance of heterojunctions between URu2Si2 and simple metals is studied and attributed to the effect of the peak of the high-density electron states, located asymmetrically with respect to the Fermi level in the HFC.
Effect of nonequilibrium structure and temperature on photoinduced changes in the optical transmission of the film YBa2Cu3O6.35
Authors: Fugol’ I. Ya. , Samovarov V. N. , Libin M. Yu.
Published: January 2025

Strong (∼25%) photoinduced changes in the optical transmission of a YBa2Cu3O6.35 film, which depend nonlinearly on the exposure time, are observed in the low-temperature region T < 125 K in a weak luminous flux (∼1013 photon/cm2·s). The conditions for a transition from nonlinear changes in the transmission to a linear law are investigated. An analysis of the effect based on the relation between the intensity of optical transitions and the change in the electron (hole) concentration in the CuO2 plane leads to the conclusion that (1) the degree of ortho-nonequilibrium of the sample forms the critical condition for effective photopumping of charge carriers for small exposure doses and at low temperatures (2) photopumping accelerates relaxation to equilibrium ortho-ordering in CuOx chains in the case of nonlinear photoinduced changes, and (3) two channels of electron transitions from CuO2 to CuOx operate simultaneously during photodoping by luminous fluxes above the metalization threshold—one for photoelectrons and the other for electrons from the Fermi level of the CuO2 plane. At 125 K, a heavily pumped film undergoes an order–disorder structural transition during which photopumped electrons (holes) are released upon an increase in temperature.
Mesoscopic fluctuations in the conductivity of tunnel contacts between a superconductor and a normal metal with localized electron states within the barrier
Authors: Demin A. V. , Khlus V. A. , Chernyakova L. P.
Published: January 2025

Peculiarities in the conductivity of superconductor–normal metal tunnel contacts with localized electron states within the barrier are considered for the case of a small number and a low density of such states. Mesoscopic effects associated with Andreev’s reflection in such systems are considered. The conductivity and its dispersion in various temperature limits are calculated. It is shown that the nonmonotonicity of the temperature dependence of the conductivity can be due to Andreev’s reflection.
Drift of magnetic domains in a weak ferromagnet DyFeO3 in ac and pulsed magnetic fields
Authors: Chizhik A. B. , Gnatchenko S. L.
Published: January 2025

A directed motion of the strip domain structure in an ac or pulsed periodic magnetic field is observed in the weakly ferromagnetic crystal of dysprosium orthoferrite. The domain structure drift has a threshold in the magnetic field amplitude. The dependence of the threshold field on frequency of ac field and the duration of the pulsed field are obtained as well as the field dependence of the drift velocity. It is found that the directed motion of the domain structure is induced by new domains formed periodically in an ac or pulsed magnetic field.
Kinetics of hardening of a supercooled liquid with concurrent formation of several solid phases
Authors: Alekseechkin N. V. , Bakai A. S. , Lazarev N. P.
Published: January 2025

The solidification of a liquid cooled at a uniform rate is studied taking into account the concurrent formation and growth of crystalline and noncrystalline nuclei. The results of kinetics of nucleation and growth of noncrystalline nuclei (clusters) are used as well as the Kolmogorov equation generalized to the case of concurrent two-component phase transition. The numerical integration of kinetic equations is used to find the dependence of the structure of a solid on the cooling rate. The size distribution functions of crystallites and clusters are studied at various cooling rates and the conditions of formation of polycrystalline, amorphous–crystalline, and polycluster amorphous solids are determined. The effect of clusterization of a liquid on the crystallization rate is explained.
Influence of a weak inhomogeneity of a tunnel barrier on localized states induced by superconducting current in a Josephson (SIS) junction
Authors: Kuplevakhskiĭ S. V. , Fal’ko I. I.
Published: January 2025

A theory is formulated to account for the influence of random structural inhomogeneities of a tunnel barrier on localized states induced by a superconducting current in Josephson junctions. A general equation for a quasidiscrete level is derived on the assumption that the fluctuations of the barrier potential are small. It is shown that the decrease in energy of the localized level and its attenuation are attributable to the finite probability of tunneling without conservation of the momentum component parallel to the barrier.
Magnetic phases and quadrupole phenomena in rare-earth orthochromites
Authors: Karnachev A. S. , Solov’ev E. E. , Lukina M. M.
Published: January 2025

The method of nuclear magnetic resonance of 53Cr nuclei is used to investigate several substituted and unsubstituted rare- earth orthochromites. A correlation is established between the magnetic ordering of Cr3+ ions and the magnitude of the quadrupole splitting of the NMR spectrum. Nonuniformities of the local and exchange fields are detected, along with an electric field gradient in the substituted orthochromites. The possible causes of these nonuniformities are discussed.
Interaction of charged particle beams with plasmons in a two-dimensional electron gas
Authors: Burtyka M. V. , Yakovenko V. M. , Yakovenko I. V.
Published: January 2025

A theory is formulated for the interaction of charged particle beams with a two-dimensional electron gas localized in the vicinity of a delta-function potential well U(y) = U0δ(y). A kinetic equation is derived for plasmons in the two-dimensional gas, the conditions for the onset of plasmon instability are given, and corresponding expressions are found for the instability growth rate.
Nuclear magnetic resonance of 69Ga and 71Ga nuclei in gallium-substituted ferric borate
Authors: Doroshev V. D. , Kol’tsov M. A. , Solov’ev E. E. , Moskvin A. S. , Seleznev V. N.
Published: January 2025

Electron–nucleus interactions in gallium-substituted ferric borate are investigated by the method of nuclear magnetic resonance of 69Ga and 71Ga nuclei at a temperature of 4.2 K. The supertransferred hyperfine fields of gallium nuclei in the investigated compound are determined here for the first time. The results are compared with the supertransferred hyperfine fields of gallium nuclei in orthoferrites.
Percolation in bismuth and vanadium films containing a normal metal–superconductor interface
Authors: Kuz’menko V. M. , Shklovskiĭ V. A. , Navozenko Yu. V.
Published: January 2025

The percolation properties of partially crystallized amorphous Bi and V films obtained by low-temperature condensation are investigated. A superconducting (S) phase and a normal (N) phase coexist at a certain temperature in such mixed amorphous–crystalline films, and their concentration ratio can be varied at will. The percolation threshold pc and the critical parameter s are evaluated in the expression given in percolation theory for the conductivity (σ) of NS systems: σ ∝ (pc‒p)‒s. The values obtained for pc and s are in good agreement with the theoretical “Swiss cheese” and “inverse Swiss cheese” models for two-dimensional systems.
Quantum features of two types of Dzyaloshinskii–Moriya coupling in antiferromagnetic spin chain
Authors: Zvyagin A. A.
Published: January 2025

A 1D spin quantum system (S= 1/2) with the Dzyaloshinskii–Moriya interaction is studied. It is shown that this type of coupling in the antiferromagnetic chain with an odd structure with respect to the main axis accounts for a staggered magnetic ordering in the ground state. For an even structure the Dzyaloshinskii–Moriya interaction causes a helicoidal spin structure only. Correlation functions are calculated under different conditions.
Magnetostriction effects in bounded magnetic media with spin reorientation
Authors: Lavrinenko N. M. , Stefanovskiĭ E. P.
Published: January 2025

It is shown that the equilibrium state of bounded magnetic materials is spatially inhomogeneous in some cases in the presence of a spinreorientation phase transition. Magnetostriction effects that induce spontaneous cylindrical flexural strain in a plane-parallel plate of a tetragonal ferromagnet are investigated.
Weak localization and hole–hole interaction effects in boron δ-layers in epitaxial silicon
Authors: Krasovitskiĭ Vit. B. , Makarovskiĭ O. N. , Mironov O. A. , Whall T. E. , Mattey N. L.
Published: January 2025

The galvanomagnetic properties of a boron δ-layer in epitaxial silicon (carrier concentration 7·1013 cm‒2) in weak magnetic fields (from 10‒3 T to 2 T) at temperatures of 1.7−50 K is reported. It is shown that the temperature dependence of the conductivity is attributable to the simultaneous occurrence of the effects of weak localization in the presence of spin–orbit interaction and hole–hole interaction in the diffusion channel. In an investigation of the temperature dependence of the magnetoconductivity and the Hall effect the contributions of the weak localization and hole–hole interaction effects are separated, and their characteristic parameters are determined. The magnetic-field dependences, which are very accurately described by the weak localization equations without regard for hole–hole interaction in the diffusion channel, are used to determine the absolute values and the temperature dependence of the phase slip time of the electron wave function: τφ ∝T‒1, which suggests that hole-hole interactions are predominant in inelastic scattering processes at low temperatures. A comparison of the magnetoresistance in magnetic fields perpendicular and parallel to the δ-layer yields the effective thickness of the quasi-two-dimensional hole channel, which is found to be equal to (8.5±0.5)·10‒9 m over the entire investigated temperature range.
Modified Ising model in external field
Authors: Kovarskiĭ V. L. , Khristov A. V.
Published: January 2025

A modified Ising model (MIM) taking into account a finite height of the energy barrier between the states is considered. The behavior of the MIM in an external static field is analyzed. The temperature dependences of susceptibility are calculated for various model parameters. A metastable state simulating glass is examined. It is shown that the dependence χ(T) can have two peaks. The calculations are made in the molecular field approximation.
Magnetic excitations in Ni(C2H8N2)2Ni(CN)4
Authors: Zvyagin S. A. , Eremenko V. V. , Pishko V. V. , Feher A. , Orendác M. , Orendác̆ová A.
Published: January 2025

A Ni(C2H8N2)2Ni(CN)4 single crystal whose magnetic structure can be regarded as a Heisenberg spin chain is studied by using the EPR method in the millimeter range. The existence of two nonequivalent positions of Ni2+ ions in the octahedral surrounding is postulated. The initial splitting of the paramagnetic levels of the Ni2+ ion is found to be (Δε = 6.5±0.3K). The value of the g-factor is determined experimentally at T = 4.2 K (g = 2.29±0.03). Peculiarities of the absorption spectrum for Ni(C2H8N2)2 Ni(CN)4 manifested in an applied magnetic field H* = 4.4±0.3T are considered. As the field is increased beyond this value, one of the doublet components becomes the lowest level of the paramagnetic ion Ni2+.
Peculiarities of magnetic resonance in CsEr(MoO4)2
Authors: Khats’ko E. N. , Pereverzev Yu. V. , Kobets M. I. , Pashchenko V. A. , Kut’ko V. I.
Published: January 2025

The magnetic resonance of CsEr(MoO4)2 is studied in a wide range of frequencies (11–190 GHz) and temperatures (1.8–35 K). It is shown that this compound belongs to Ising magnets with a strong anisotropy of spin–spin interactions. The observed triplet structure of the spectrum is explained by the presence of Ising ferromagnetic chains along the b-axis The interactions in a chain are estimated. An additional absorption line observed for H∥b is explained in terms of a four-level model as a transition between the ground and excited doublet states. A spectral singularity associated with a structural phase transition induced by the applied magnetic field is observed along the c-axis.
Thermal conductivity of quasi-two-dimensional organic superconductor κ-(ET)2Cu[N(CN)2]Br
Authors: Efimov V. B. , Mezhov-Deglin L. P. , Makova A. M.
Published: January 2025

The temperature dependences of the thermal conductivity κ and electrical conductivity σ of quasi-two-dimensional organic superconductor κ-(ET)2Cu[N(CN)2]Br with the superconducting transition temperature Tc ≃ 11 K are measured in the direction of the conducting ac-plane. It is shown that heat transport in the crystal from room-to helium temperatures is controlled by phonons. The effective mean free paths λph of phonons at temperatures above that corresponding to the κ(T) peak (T > 15 K) is limited by the phonon–phonon scattering as well as the scattering by point defects. Below the temperature corresponding to the thermal conductivity peak, scattering at macroscopic defects of the type of grain boundaries or dislocation walls in the bulk of the sample dominates.
Anion photoelectron imaging and theoretical study of Cu(CO)3−
Authors: Li Zhen , Liu Wenli , Hu Gaoming , Zhu Boxing , Zhang Qiang , Chen Yang , Zhao Dongfeng
Published: January 2025

Photoelectron velocity map images of Cu(CO)3− have been experimentally recorded in the 700–1100 nm range. The infrared-inactive Cu-C symmetric stretching modes for Cu(CO)3 (v2 ≈ 367 cm−1) and Cu(CO)3− (v2 ≈ 408 cm−1), as well as the electron affinity (1.03±0.11 eV) of Cu(CO)3, are accurately determined from high resolution photoelectron spectra. In combination with quantum chemical calculations and bonding analyses, the coordination bonds in both Cu(CO)3− are Cu(CO)3 are found to be due to back-donation π bonding type, formed via electron promotion from Cu’s 4s orbital to the 4p orbital, which is consequently donated to the unoccupied anti-bonding π* orbitals of the carbonyl groups. The attachment of an additional electron to Cu(CO)3 strengthens the Cu-CO coordination, making Cu(CO)3− more stable. The intramolecular interactions between the Cu/Cu− and carbonyl groups are found to be primarily governed by electrostatic forces and orbital interactions.
Combined experimental and theoretical study on low-lying electronic states of CuO−
Authors: Hu Gaoming , Li Zhen , Liu Wenli , Zhang Qiang , Zhu Boxing , Chen Yang , Zhao Dongfeng
Published: January 2025

We present a combined experimental and theoretical study on the electronic structure and bonding characteristics of the CuO− anion. On the experimental side, high resolution photoelectron imaging has allowed the detection of new features of the low-lying states of the CuO−. Supporting MRCI+Q calculations with inclusion of complex spin-orbit coupling effects have yielded complemented assignments of the photoelectron spectra obtained in the present and previous experiments to low-lying spin-orbit mixed states, which also reveal strong multiconfiguration correlation effects in CuO−. Analyses on the experimentally measured photoelectron angular distributions indicate that, the Cu–O bond in the X1Σ+ state can be characterized by mixed ionic and covalent interactions, with the ionic character being more dominant, while the a3П state can be characterized by a typical ionic bond. Our results provide a renewed understanding in the interplay of ionic-covalent bonding characters in the diatomic CuO− anion.
Broadband coherent Fourier scatterometry: A two-pulse approach
Authors: van der Sijs T. A. , Rafighdoost J. , Siaudinyte L. , Urbach H. P. , Pereira S. F. , El Gawhary O.
Published: January 2025

We demonstrate a broadband implementation of coherent Fourier scatterometry (CFS) using a supercontinuum source. Spectral information can be resolved by splitting the incident field into two pulses with a variable delay and interfering them at the detector after interaction with the sample, bearing similarities with Fourier-transform spectroscopy. By varying the time delay between the pulses, a collection of diffraction patterns is captured in the Fourier plane, thereby obtaining an interferogram for every camera pixel. Spectrally resolved diffraction patterns can then be retrieved with a per-pixel Fourier transform as a function of the delay. We show the physical principle that motivates the two-pulse approach, the experimental realization, and results for a silicon line grating. The presented implementation using a supercontinuum source offers a cost-effective way to acquire multi-wavelength CFS data over a wide wavelength range, with the potential to improve reconstruction robustness and sensitivity in applications such as dimensional metrology.