bluuebunny/crossref_metadata_2025 huggingface dataset:
Real‐time object detection for unmanned vehicles in Bangladesh: Dataset, implementation and evaluation
Authors: Ali Muhammad Liakat , Biswas Topu , Akter Shahin , Jawad Mohammed Farhan , Ullah Hadaate
Published: December 2024

Automated vehicle detection within the advanced application framework of autonomous vehicles significantly enhances road safety compared to human drivers on roads and highways. However, the intelligent identification of road vehicles in a densely populated country like Bangladesh is challenging due to irregular traffic patterns, highly diverse vehicle types, a cluttered environment, and a lack of high‐quality datasets. This study proposes a system that utilizes computer vision technology to identify road vehicles with greater speed and accuracy. First, the dataset was collected and organized in Roboflow to identify the 21 classes of Bangladeshi native vehicle images, along with two additional classes for people and animals. Subsequently, the You Only Look Once v5 (YOLOv5) model underwent training on the dataset. This process produced bounding boxes, which were then refined using the non‐maximum suppression technique. The loss function complete intersection over union is employed to obtain the accurate regression bounding box of the vehicles. The MS COCO (Microsoft Common Objects in Context) dataset weights are included in the YOLOv5 deep learning network for transfer learning. Finally, Python TensorBoard was used to evaluate and visualize the model's performance. The model was developed and validated on the Google Colab platform. A set of experimental evaluations demonstrate that the proposed method is effective and efficient in recognizing Bangladeshi vehicles. In all test road scenarios, the proposed computer vision system for road vehicle identification achieved 95.8% accuracy and 0.3 ms processing time for 200 epochs. This research could lead to intelligent transportation systems and driverless vehicles in Bangladesh.
Molecular identification and subtyping of Cryptosporidium spp. in laboratory mice and rats
Authors: Zhou Shanshan , Hu Xinyu , Li He , Yuan Zhongying , Li Zhen , Liu Aiqin , Jiang Yanyan , Cao Jianping
Published: December 2024

Cryptosporidium species can infect humans and more than 260 animal species, including 54 rodent species. However, data on the occurrence and genetic characterizations of Cryptosporidium spp. in laboratory rodents are limited. The present study aimed to determine the occurrence rate and genetic characterizations of Cryptosporidium spp. in laboratory mice and rats. We collected 506 fresh combined fecal pellet specimens (457 from mice and 49 from rats) of more than 2,000 laboratory rodents in Heilongjiang Province and Shanghai City, China. Cryptosporidium spp. were identified and subtyped by DNA sequencing of the SSU rRNA and the gp60 genes, respectively. By sequence analysis of the SSU rRNA gene, the occurrence rate of Cryptosporidium spp. was 16.6% (84/506) in combined fecal specimens, with 18.2% (83/457) for mice and 2.0% (1/49) for rats. Cryptosporidium parvum (n = 39), C. tyzzeri (n = 33), and C. parvum + C. tyzzeri (n = 11) were identified in mice. Cryptosporidium parvum was only detected in one rat fecal specimen. At the gp60 locus, 71.4% (60/84) of the Cryptosporidium-positive specimens were successfully amplified, and they all came from mice. We identified five C. parvum subtypes (IIaA14G2R1, IIaA16G2R1, IIaA17G1R1, IIaA17G2R1, and IIaA18G2R1) and two C. tyzzeri subtypes (IXaA6R1 and IXbA8). Based on the identification in laboratory mice of C. parvum subtypes that have been reported previously in humans, the mice infected with this species may threaten human health, especially for people who have contact with the animals and their feces.
Begleitende Therapie von Otitis media bei Kindern
Authors: Corts Magga , Welsch Katja , Dichtl Karoline , Löwensprung Nathalie Rosenhauer-von
Published: December 2024

4 Expert*innen stellen Ihnen Behandlungsstrategien aus der Biochemie nach Dr. Schüßler, Anthroposophie, Osteopathie und Homöopathie vor.
Der weibliche Beckenboden im Sport
Authors: Leitner Monika
Published: December 2024

Aus Studien weiß man, dass eine erhebliche Anzahl weiblicher Athleten Probleme damit hat, beim
Sporttreiben den ungewollten Abgang von Urin zu verhindern. Doch immer noch ist die Belastungsinkontinenz
im Sport ein Tabuthema. Es wird höchste Zeit, mit mehr Aufklärung und geeigneten Maßnahmen betroffenen
Frauen zu helfen.
Wenn alles neu und herausfordernd ist
Authors: Opalka Markus
Published: December 2024

Neugeborene befinden sich in einer intensiven Entwicklungsphase mit kognitiven und neuronalen Anpassungen, die jedes Kind selbst regulieren muss. Der Omega-3-Spiegel, die Darmflora, die Schlafposition des Babys – eine genaue Betrachtung dieser 3 Faktoren hat sich in der Praxis bei Problemen bewährt. Gezielte Unterstützungsmaßnahmen fördern die Fähigkeit zur Selbstregulation und schaffen gute Startbedingungen für ein gesundes Leben.
Vom Vibrationstrauma zur pharyngealen Muskelinstabilität – Ein sich selbst unterhaltender pathophysiologischer Prozess (Circulus vitiosus) bei obstruktiver Schlafapnoe (OSA)
Authors: Koehler Ulrich , Hildebrandt Olaf , Degerli Mikail Aykut , Viniol Christian , Hildebrandt Wulf , Conradt Regina , Birk Richard , Stuck Boris , Sambale Janine , Korbmacher-Steiner Heike
Published: December 2024

Die Pharynxstabilität wird sowohl durch anatomische als auch nicht-anatomische Faktoren gewährleistet. Neben der anatomischen Weite sind auch funktionelle Faktoren für den Obstruktionsgrad des oberen Atemwegs bedeutsam. Die Funktionsfähigkeit der pharyngealen Muskeln ist von einer ungestörten Sensomotorik abhängig. Bei Patienten mit Rhonchopathie bzw. obstruktiver Schlafapnoe (OSA) verändern sich Sensomotorik und Muskelmorphologie in zunehmendem Ausmaß. Es ist zu mutmaßen, dass langjähriges Schnarchen zu einer vibrationsbedingten sensomotorischen Neuropathie mit Verlust der Funktion und Struktur der pharyngealen Muskulatur führt. Pharyngeale Mechanorezeptoren verlieren ihre Empfindlichkeit und die Informationen können aufgrund eines neuronalen Schadens nicht mehr adäquat motorisch umgesetzt werden. Es stellt sich die Frage, nach welchem Zeitraum es zu einem irreversiblen vibrationsbedingten Rezeptorschaden durch Schnarchen kommt.
Incisionless Otoplasty: Current State of the Art
Authors: Madsen Buba Cibele , Gantous Andres
Published: December 2024

Prominent ears, also known as prominauris, inflict psychological distress and suffering on both children and adults. Otoplasty has become one of the most common aesthetic operations due to its high prevalence and significant impact on patients. Various surgical techniques for otoplasty have been documented and developed over time. While complications are rare, open and cartilage-resection techniques may result in hemorrhage, hematomas, contour deformities, hypertrophic scarring, and keloid formation. Incisionless otoplasty has been demonstrated in the literature to be an effective method, when correctly indicated, to correct prominauris with a shorter recovery time and reduced morbidity. A thorough preoperative evaluation, awareness of the different techniques, and assessment of their appropriate application minimize potential risks and unpleasant results.
Mitochondriale Dysfunktion – Treiber der Seneszenz und chronischer
Erkrankungen
Authors: Friedrichsen Hans-Peter , Gröber Uwe
Published: December 2024

Die mitochondriale Dysfunktion ist charakterisiert durch eine Dysbalance zwischen
ATP-Synthese, also Energieproduktion, einerseits und ROS(Reactive Oxygen
Species)-Bildung, also oxidativer Belastung, andererseits. Die Ursachen dafür
sind vielfältig und reichen von angeborenen Störungen, z. B. bei den
Enzymkomplexen der ETK (Elektronentransportkette) wie beim Down-Syndrom bis zu
neurotoxischen Schädigungen z. B. durch Quecksilber. Es resultiert ein
Energiedefizit und/oder eine erhöhte oxidative Belastung in dem betroffenen
Gewebe mit vielfältigen Folgeerscheinungen. Die durch mitochondriale Dysfunktion
ausgelösten Gesundheitsstörungen reichen dabei von A wie Arteriosklerose bis Z
wie zerebrale Insuffizienz.
Trieb mit Bedeutung – Überlegungen im Anschluss an die Sigusch-Schmidt-Kontroverse
Authors: Lahl Aaron
Published: December 2024

Einleitung Der Trieb gehört zu den provokantesten und umstrittensten Annahmen der Psychoanalyse. Im deutschsprachigen sexualwissenschaftlichen Diskurs stehen Gunter Schmidt mit seiner kritischen Historisierung des Triebkonzepts und Volkmar Sigusch mit seinem „Lob des Triebes“ exemplarisch für zwei widerstreitende Positionen zum Triebkonzept.

Forschungsziele Der Beitrag möchte die seit Mitte der 1970er-Jahre und bis in die jüngere Vergangenheit geführte Debatte zwischen Schmidt und Sigusch rekonstruieren und dabei konzeptuelle Unklarheiten und Missverständnisse auf beiden Seiten herausarbeiten. Letztlich geht es dabei um das fragliche gesellschaftskritische Potenzial des Triebbegriffs.

Methoden Es wird zwischen einer psychologisch-konzeptuellen und einer zeitdiagnostischen Ebene in der Debatte differenziert und es werden zentrale Argumente Schmidts und Siguschs auf diesen Ebenen herausgearbeitet. Zur Frage der von Sigusch und Schmidt nur ungenügend theoretisierten Dialektik von Sexuellem und Nicht-Sexuellem wird Jean Laplanches „ Allgemeine Verführungstheorie“ in die Debatte eingebracht.

Ergebnisse Schmidt kritisiert ein vereinfachtes Konzept des Triebes, wenn er einen Gegensatz von Trieb und Bedeutung behauptet. Seine Kritikpunkte laufen gegen einen dialektischen Triebbegriff im Anschluss an Sigusch und Laplanche ins Leere. Die zeitdiagnostischen Differenzen zwischen den liberal-optimistischen Einschätzungen Schmidts und den pessimistischen Urteilen Siguschs lassen sich als Konsequenzen aus der ursprünglich differenten Konzeption sexueller Motivation verstehen. Beide Diagnosen werden als vereinfacht problematisiert.

Schlussfolgerung Der Artikel schließt mit einem Plädoyer für den Trieb als Grundbegriff einer kritischen Sexualwissenschaft, in dessen Konzeption theoretische Impulse sowohl von Schmidt als auch Sigusch aufgenommen werden.
Association between Slow and Rapid Weight Gain before 36 Weeks of Corrected Age and 6-Year-Developmental Quotient in Infants Born at <26 Weeks of Gestation
Authors: Hotta Masashi , Hirata Katsuya , Hirano Shinya , Wada Kazuko
Published: December 2024

Objective The postnatal growth of preterm infants is influenced by various factors; however, the association between growth and long-term outcomes in extremely preterm infants remains unclear. Therefore, we aimed to determine the association between 6-year development and body weight (BW) at 36 weeks of corrected age (CA) in extremely preterm infants.

Study Design We conducted a retrospective observational study including extremely preterm infants born at < 26 weeks of gestation. We defined the key standard deviation score (SDS) using BW at birth and evaluated the association between BW-related values at 36 weeks of CA and the 6-year developmental quotient (DQ).

Results This study included 90 infants. The absolute difference between changes in the BW SDS from birth and the median changes in DQ ≥ 85 infants was significantly greater in infants with a DQ < 85 than ≥85 (median [interquartile range]: 0.80 [0.29, 1.31] vs. 0.34 [0.13, 0.55]; p = 0.001). After adjustment by the logistic regression analysis for DQ < 85, the absolute difference was statistically significant (odds ratio: 4.99, 95% confidence interval: 1.71–14.5). The correlation coefficient between the absolute difference and DQ was −0.35 (p < 0.001). There were no significant associations between a DQ < 85 and SDS or changes in SDS from birth.

Conclusion For infants born at <26 weeks of gestation, slow and rapid weight gain were associated with a low 6-year DQ when using values representing individual body sizes at birth. Individual backgrounds should be considered to avoid both slow and rapid weight gain for the growth management of these infants for at least up to 36 weeks of CA. Further research is needed to determine which body size has a positive impact on the long-term outcomes of infants.

Key Points
Simplifying Management of Cholestasis: A Proposal for a Classification System
Authors: Sarker Minhazur , Ramos Gladys A. , Ferrara Lauren , Gyamfi-Bannerman Cynthia
Published: December 2024

Given the stillbirth risk associated with intrahepatic cholestasis of pregnancy, management to reduce this adverse outcome has primarily involved planned delivery as early as 36 weeks gestation. While earlier planned delivery has decreased the incidence of stillbirth in this population, recently, there have been multiple published retrospective studies to better correlate the association of adverse outcomes with cholestasis severity. Despite these new data, the uptake of individualized management for cholestasis has been varied from provider to provider. In this opinion, we briefly review the current literature and evidence regarding cholestasis and adverse outcomes and propose a cholestasis classification system with subsequent algorithms for management.

Key Points
Derivation and Validation of Prediction of Preterm Preeclampsia Using Machine Learning Algorithms
Authors: Kawakita Tetsuya , Martins Juliana G. , Diab Yara H. , Nehme Lea , Saade George
Published: December 2024

Objective This study aimed to develop machine learning (ML) models for predicting preterm preeclampsia using the information available before 23 weeks gestation.

Study Design This was a secondary analysis of the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be (nuMoM2b) cohort. We considered 131 features available before 23 weeks including maternal demographics, obstetrics and family history, social determinants of health, physical activity, nutrition, and early second-trimester ultrasound. Our primary outcome was preterm preeclampsia before 37 weeks. The dataset was randomly split into a training set (70%) and a validation set (30%). ML models using glmnet, multilayer perceptron, random forest, XGBoost (extreme gradient boosting), and LightGBM models were developed. Using the ML approach that achieved the best area under the curve (AUC), we developed the final model. Further feature selection was conducted from the top 25 important features based on SHapley Additive exPlanations (SHAP) values. The performance of the final model was assessed using the validation dataset.

Results Of 9,467 individuals, 219 (2.3%) had preterm preeclampsia. The AUC of the XGBoost model was the highest (AUC = 0.749 [95% confidence interval (95% CI), 0.736–0.762]) compared with other models. Therefore, XGBoost was used to develop models using fewer variables. The XGBoost model with the eight features (in order of importance: mean uterine artery pulsatility index in the early second trimester, chronic hypertension, pregestational diabetes, uterine artery notch, systolic and diastolic blood pressure in the first trimester, body mass index, and maternal age) was chosen as the final model as it had an AUC of 0.741 (95% CI, 0.730–0.752) which was not inferior to the original model (p = 0.58). The final model in the validation dataset had an AUC of 0.779 (95% CI, 0.722–0.831). An online application of the final model was developed (
https://kawakita.shinyapps.io/Preterm_preeclampsia/
).

Conclusion ML algorithms using information available before 23 weeks can accurately predict preterm preeclampsia before 37 weeks.

Key Points
A Child with Non-Growth Hormone-Deficient Short Stature with Chromosome 2 Deletion of 2q35-36.1: A Case Report and Literature Review of Haploinsufficiency of Epha4 Gene
Authors: Sun Jun , Xiao Ya , Jiang Shu-qin , Wang Yi-fan , Zhang Hong-ru , Wang Wei
Published: December 2024

Non-growth hormone-deficient short stature is a group of growth developmental disorders with complex pathophysiological mechanisms involving multiple pathways, including abnormalities in the growth hormone/insulin-like growth factor 1 signal pathway. We report a 4-year-old girl with severe growth and developmental delay: her height was 91 cm (<–3 standard deviation [SD]), and her growth rate was 3 to 4 cm/year (<–2 SD). Growth hormone stimulation tests indicated a normal peak growth hormone level (11.1 μg/L), while insulin-like growth factor-1 levels were reduced (7.98 nmol/L, <–1SD). Whole exome sequencing and copy number variation analysis revealed a 3.19 Mb deletion at 2q35-q36.1 on chromosome 2, encompassing all coding regions of the Epha4 gene. This study suggests an association between Epha4 gene deletion and non-growth hormone-deficient short stature, highlighting the importance of further research on this gene and its related signaling pathways to understand the molecular mechanisms of the disease and potential therapeutic approaches.
Thermodynamic properties of liquid Ne–H2 solutions
Authors: Marinin V. S. , Pashkov V. V. , Khokhlov Yu. I.
Published: December 2024

Thermodynamic perturbation theory is used to study p-v-T relationships, liquid-vapor phase equilibrium, compressibility, and speed of sound in liquid Ne–H2 solutions. Special attention is given to calculation of excess volume, both along isobars and on the saturation line; excess volme values at high pressures are predicted.
Current states and band spectrum of a condensate in superconducting superstructures
Authors: Omel’yanchuk A. N. , Gogadze G. A. , Kulik I. O.
Published: December 2024

The dependence of the current on the “macroscopic quasimomentum” ps in a system with periodically varying order parameter in space is investigated (superconducting superstructure). This dependence has the nature of a non-monotonic function which vanishes every time the quasi-momentum is a multiple of the quantity πℏ/a (a is the superstructure period). There is a finite number of bands (branches) of the functions j = jn(ps) and energies E = En(ps) whose number is of the order of pca/ℏ where pc is the critical momentum of breaking the homogeneous current state. The function j(ps) becomes single-valued upon achievement of the threshold degree of modulation of the superlattice order parameter, namely, in this case qualitative distinctions between the band pattern and the homogeneous current state occur.
Electron energy structure in conductors with magnetic domain structure
Authors: Bass F. G. , Fal’ko V. L.
Published: December 2024

The electron energy spectrum in a spatially periodic magnetic field is found and shown to have a band structure. Band parameters are determined in the weak and strong coupling approximations, together with the magnetic field dependence of forbidden and permitted band widths. Surface states analogous to Tamm levels in a crystal are studied.
Electromagnetic excitation and dispersion of the velocity of sound in nickel in high magnetic fields
Authors: Drobot’ko V. F. , Naberezhnykh V. V.
Published: December 2024

An experimental study is made of frequency resonant changes in surface impedance produced by excitation of standing sound waves in a nickel monocrystal. Also studied are dispersion of the speed of sound and damping of sound waves as a function of the magnitude of a constant magnetic field H0 at a temperature of 4.2°K. It is established that in magnetic fields exceeding the field of magnetic saturation of the specimen at low temperatures conversion of an electromagnetic wave into a sound wave within the skin layer of ferromagnetic nickel is controlled by an induction mechanism of conduction electron interaction with the lattice. This same mechanism determines sound damping in strong magnetic fields. The dispersion of the speed of sound within the specimen volume is then produced by the magnetoelastic mechanism of interaction of the magnetization M with the lattice deformation. The possibility of determining the magnetoelastic constants of nickel by electromagnetic excitation of sound is considered.
Nonlinear magnetization of metals
Authors: Nedorezov S. S.
Published: December 2024

The magnetic susceptibility χ of metals near the 2 1/2 order electronic transition is considered with account of the spin-orbit interaction. Relations are obtained, describing the electronic susceptibility of h.c.p. metals when changes occur in the isoenergetic surface topology. The anomalies in the temperature and magnetic field dependences of the magnetic susceptibility χ, observed in cadmium-magnesium alloys, are shown to be in good agreement with theory. A non-monotonic H-dependence of χ with an extremum in the weak field region is predicted. This extremum is due to intraband magnetic breakdown in the vicinity of the conical point.
Magnetic structures in manganese phosphide
Authors: Kovalev O. V.
Published: December 2024

A method of studying successive magnetic structures is described in the case where these structures include a helical one. On the basis of experimental data and with the aid of an additional introduced relation, the range, of values of interaction parameters is established within which a sequence of magnetic phases can exist in manganese phosphide.
Structural and activation characteristics of nickel creep in the temperature range from 4.2 to 140°K
Authors: Aksenov V. K. , Gindin I. A. , Lebedev V. P. , Starodubov Ya. D.
Published: December 2024

We studied the creep of polycrystalline nickel at various levels of stress and determined the activation energy, activation volume, and the effective stresses in the temperature range from 4.2 to 140°K. Using electron microscopy and measurements of the electrical resistivity, we studied the defect structure formed in the transient stage of creep at various temperatures. On the basis of a parallel analysis of the temperature and effective-stress dependences of the activation characteristics as well as the structural state in the course of creep we come to the conclusion that dislocations within the boundaries of cells control the low-temperature creep of nickel over the entire range of temperatures and stresses investigated.
Change of the electronic spectrum of antimony under plane strain
Authors: Posledov Yu. A.
Published: December 2024

Changes in the electronic band structure of antimony single crystals under plane strain in a ring-type arrangement [N.B. Brandt et al., Fiz. Nizk. Temp. 4, 489 (1978)] are studied by the Falicov–Lin pseudopotential method, using previously developed numerical methods [Yu.A. Posledov, Pis’ma Zh. Eksp. Teor. Fiz. 29, No. 4 (1979)]. To determine the deformation of the Sb lattice we calculated the stress tensor under stretching in the described apparatus. The changes of the extreme cross sections of the Fermi surface are in good agreement with the corresponding experimental data (N.B. Brandt et al., loc. cit.). When the crystal is stretched along the binary or bisector axis in the ring-type apparatus, the changes of the Fermi surface result in the redistribution of current carriers among the different ellipsoids. Within the accuracy of the calculation, the total current-carrier concentration remains constant.
Excitation of cyclotron waves in metals with a diffuse boundary
Authors: Makarov N. M. , Fal’ko V. L. , Yampol’skii V. A.
Published: December 2024

Excitation of short cyclotron waves in metals by an external electromagnetic field is investigated theoretically. Electron scattering by the specimen boundary is assumed diffuse. It is shown that a wave is generated in the main skin layer and in spikes of the anomalous penetration field. Asymptotically exact formulas are obtained which describe the excited cyclotron wave field. Differences in the process of cyclotron wave excitation for diffuse and specular electron scattering are discussed.
Effect of pressure on anisotropy of magnetic susceptibility of Cd–Mg alloys
Authors: Manchenko V. N. , Svechkarev I. V. , Sereda Yu. P.
Published: December 2024

Pressure-induced changes in the anisotropy of the magnetic susceptibility of cadmium single crystals and Cd1–x Mgx alloys (x <0.02) were studied in the liquid-hydrogen temperature range. Pressure-initiated 2 1/2- order electronic phase transitions allowed estimates on the basis of the concept of an effective temperature, to be made of the effect of scattering in orbital magnetism associated with magnesium impurities in the cadmium matrix: T* = 13 ±1 °K/at.% Mg.
Temperature dependence of the antiferromagnetic-resonance frequencies and integral line intensities in crystals with single ion anisotropy
Authors: Kitaev V. N. , Pervukhin N. A.
Published: December 2024

A Heisenberg antiferromagnet with spin S = 1 is considered and the permissible range of values for the constants of single ion anisotropy is examined. The temperature dependence of the frequencies and the integral intensities in the various branches of the antiferromagnetic-resonance spectrum are sought by the generalized self-consistent field method. On the basis of the results we predict the possibility of some antiferromagnetic-resonance frequencies anomalously increasing with temperature and it is predicted that below the Néel point the intensity of the absorption peak, with longitudinal ploarization of the radio­frequency field, will be independent of the temperature.
Influence of a constant magnetic field on the electrical resistivity of nickel ultrasonically deformed at low temperature
Authors: Belostotskii V. F.
Published: December 2024

The results of measurements of the residual resistivity of nickel deformed at a frequency of 17.5 kHz in liquid helium in a constant magnetic field ranging from 10 to 1500 Oe are presented. It is found that the increase in the residual resistivity of nickel after ultrasonic deformation in a magnetic field is larger than after an analogous deformation without application of the field. It is proposed that the observed effect is magnetoplastic in origin.
Low frequency absorption spectra of α-nitrogen
Authors: Fugol’ I. Ya. , Khashchina L. V.
Published: December 2024

Infrared absorption spectra of α-nitrogen were studied in the region of phonon vibrations (30–100 cm−1) at a temperature of 8 °K. The resolution of 0.6 cm−1 achieved made it possible to refine the literature values for the frequencies of the bands and to observe several new librational modes, nearly forbidden in IR absorption. It is suggested that the breakdown of the selection rules is caused by the presence of 0.7% of 14N15N molecules in the naturally occurring isotopic mixture of N2 gas.
Anharmonic renormalization of the phonon spectrum of inert crystals
Authors: Ratner A. M. , Shamfarova O. Ya.
Published: December 2024

The calculation of an anharmonic lattice is typically carried out by the method of self-consistent phonons, which does not admit a quantitative error estimate. In the present work we employ an alternate approach, based on a variational technique, the errors of which may be rather precisely calculated and accounted for in the results. The systematic error in the variational method, δ, characterized by an increase in the phonon frequencies, is calculated by replacing the crystal by a one-dimensional system, which is simultaneously calculated exactly and by the variational technique. One dimensional motion of an atom takes place in the field U(x) = u(x) + u(2l — x), where u is the pair potential of its neighbors, located at a distance 2l. Since u(x) has a minimum at a point xm≠l, the behavior of the even function U near the minimum point l is determined by both the even and the odd anharmonicities of the pair potential u. Thus, U″ = 2u″(l) = 2u″(xm) + 2u″(xm)+2u‴(xm)(l — xm) + ... The one-dimensional model, which represents the anharmonicity of the potential fairly well, also achieves a fair description of the lattice thermodynamics. The error δ, calculated from the one-dimensional model and the anharmonic renormalization of the spectrum α, corrected for the value of δ, are tabulated as a function of T. At T = 0, the values of α for crystals of Ne, Ar, and Kr are, respectively, 32, 8, and 4% (δ = 12,4, and 2.5%).
Ellipticity and inclination of the plane of rotation for a magnetic spiral in MnP
Authors: Kovalev O. V.
Published: December 2024

It is shown that the magnetic energy may be minimized for an MnP crystal by means of a double circular spiral, but only if one neglects the nonexchange interaction. Ellipticity arises if the latter is incorporated. A perturbation method is used to examine the error arising on replacing a real crystal with four Mn atoms in the unit cell by a model with two atoms and a higher symmetry group. It is shown that the displacement of the atoms in a real crystal perpendicular to the axis of the spiral results in a magnetic density periodic along the axis of the spiral.
Effect of bound impurity pairs on surface tension of helium solutions
Authors: Antsygina T. N. , Slyusarev V. A.
Published: December 2024

The effect of bound He3 impurity pairs located in surface states of He3−He4 liquid solutions on system properties is studied. It is shown that in the temperature range below the binding energy, consideration of the interaction leading to pair formation significantly changes the temperature dependence of the excess surface tension produced by the He3 impurities. The results obtained are compared with data of earlier studies.
Magnetic properties and energy spectrum of Cd1−xMgx alloys
Authors: Grechnev G. E. , Svechkarev I. V. , McClure J. W.
Published: December 2024

The Fukuyama theory of conduction electron magnetism and the K·p model Hamiltonian are used to analyze the magnetic properties of Cd1−xMgx alloys. The experimental information on the effect of impurity scattering on the magnetic susceptibility was also used. By comparing quantitatively the experimental and theoretical value of the magnetic susceptibility we determined the parameters of the energy spectrum of pure cadmium crystals which agree well with the results of a direct calculation of the spectrum using the Stark–Auluck nonlocal pseudopotential. The effect of isovalent impurities (up to 12 at.% Mg) on the parameters of the spectrum is also determined.
Static magnetic properties of a spin chain with an impurity
Authors: Kleiner V. Z. , Tsukernik V. M.
Published: December 2024

A one-dimensional spin system with XY-interaction which contains a substitutional impurity is examined for two orientations of the permanent magnetic field, along and perpendicular to the selected direction. Field and temperature dependences are found for the magnetic moment of the impurity and the host. It is shown that a change in the relationship between the system parameters substantially influences the nature of this dependence.
Exchange symmetry of magnetically ordered crystals
Authors: Bar’yakhtar V. G. , Yablonskii D. A.
Published: December 2024

We present a phenomenological method which makes it possible, in the framework of the exchange approximation, to find the possible microscopic spin-density distribution compatible with a given lattice space group in the magnetically ordered state. All the possible magnetic structures (homogeneous and helical) are found and classified according to symmetry types. The classification is similar to that suggested by Andreev and Marchenko [Zh. Ésp. Teor. Fiz. 70, 528 (1976)].
First principles calculation of the hole bands in crystalline Ne
Authors: Sribnaya V. K. , Tolpygo K. B.
Published: December 2024

We have calculated the hole bands in crystalline Ne under the assumption that the removal of one electron from the filled 2p shell has a small effect on the state of the remaining electrons. We have used the wave functions previously calculated by /V. F. Brattsev, Tables of Atomic Wave Functions /in Russian/, Nauka, Moscow–Leningrad (1966), p. 192, which we have approximated products of exponentials exp (−αir) and polynomials of first order in r. The minimum hole energy is ∼20.72 eV and the width of the hole band is about 0.523 eV. Calculated values of the effective mass at the Гl5 point are given for various directions of the wave vector. They range from 4.2 to 80.5 me.
Temperatures attainable by adiabatic demagnetization of cerium–lanthanum–magnesium nitrates
Authors: Odehnal M. , Švec K. , Koláč M. , Matas J. , Těthal T. , Šafrata R. S. , Fialovă M.
Published: December 2024

A new expression is derived for the final temperature Tf attainable by adiabatic demagnetization of a paramagnetic salt to a zero intensity of the external magnetic field. This expression, based on the first three terms in the high-temperature van Vleck series expansion of the magnetic entropy Sm, takes into account dipole–dipole interaction of magnetic-ion moments as well as interaction of these moments with proton spins. For cerium–lanthanum–magnesium nitrate (CexLa1−x)2Mg3(NO3)12·24H2O this expression describes the dependence of the final temperature Tf on the cerium content x in close agreement with experimental data.
Temperature dependences of sound absorption and dispersion associated with Fermi-surface plateaus
Authors: Stepanova N. A. , Kopeliovich A. I.
Published: December 2024

It is shown that Fermi surface plateaus (points, lines, and sections of zero curvature) result in temperature dependences of the sound absorption and dispersion in the “collision-free” domain kl>1. The temperature and frequency dependences characteristic for different kinds of plateaus are considered.
Superconducting fluctuations in thin tin films deposited at helium temperature
Authors: Belevtsev B. I.
Published: December 2024

We examine the variation in the critical superconducting transition temperature of thin tin films prepared at 4.2 °K as a function of thickness and annealing temperature together with the effect of fluctuations on Tc and on the shape of the curves of R(T) of the superconducting transition.
Magnetization stimulation in ferromagnets by an alternating magnetic field
Authors: Seminozhenko V. P. , Yatsenko A. A.
Published: December 2024

It is shown that a nonresonant alternating magnetic field can result in nonequilibrium stationary magnon states in which the magnetization will exceed its equilibrium value. This effect is analogous to the Éliashberg effect of superconductivity stimulation.
Performance estimation of a piezoelectric energy harvester with rotatable external magnets
Authors: Cui Diandian , Shang Huilin
Published: December 2024

This study estimates the performance of a piezoelectric energy harvester (PEH) with rotatable external magnets from the viewpoint of global dynamics. According to static analysis of the PEH dynamic system, the monostable and bistable potential wells are configured under different values of the inclined angle of the external magnets. In the monostable case, the method of multiple scales is applied for the analysis of periodic responses, while the extended averaging method and the Melnikov method are utilized to analyze the periodic and chaotic responses in the bistable case. Numerical results are in great agreement with the theoretical ones. It follows from the comparison of the dynamical behaviors in the two cases that the bistable-well configuration is more efficient in harvesting vibration energy under low-frequency or low-level ambient excitation. In the bistable case, sequences of the coexisting attractors and basins of attraction (BAs) with the increase in the excitation strength are presented, illustrating that the inter-well periodic and chaotic responses can be successively triggered by the rise in the excitation level, and which attractor will contribute to increasing the voltage output depends on the location and size of their BAs. With the increase in the excitation level, rich nonlinear dynamic phenomena, such as multistability, period-2 attractors, chaos, fractal BAs, and hidden attractors, can be observed.
Hopf-like bifurcations and multistability in a class of 3D Filippov systems with generalized Liénard’s form
Authors: Wang Fanrui , Wei Zhouchao , Zhang Wei , Kapitaniak Tomasz
Published: December 2024

Based on the observable conditions of control systems, a class of 3D Filippov systems with generalized Liénard’s form is proposed. The bifurcation conditions for two types of Hopf-like bifurcations are investigated by considering the stability changes of the sliding region and the invisible two-fold point. The primary objective of this paper is to elucidate the sudden transitions between attractors. Phase portraits, bifurcation diagrams, time series diagrams, Poincaré maps, and basins of attraction are utilized to illustrate the novel and intriguing chaotic behaviors. The simulation results indicate that after undergoing the Hopf-like bifurcation of type I, the proposed system can exhibit multiple types of attractors within remarkably narrow intervals. Even when the pseudo-equilibrium disappears, the multistable phenomena can still emerge by adjusting the parameters.
Applying the Stackelberg game to assess critical infrastructure vulnerability: Based on a general multi-layer network model
Authors: Li Haitao , Ji Lixin , Wang Kai , Liu Shuo , Liu Shuxin
Published: December 2024

Critical infrastructure systems (CIS) are closely related to human life. Attacks against CIS occur frequently, making accurate and effective protection of CIS essential. Vulnerability assessment is the primary issue to achieving this goal. The interconnected characteristic of CIS means that it is best represented by a multi-layer network, but a uniform model is absent. Game theory offers a suitable framework for researching intelligent confrontation. Previous research combining game theory and network science mainly focuses on a single-layer network and lacks a comprehensive assessment that combines qualitative and quantitative aspects of vulnerability. In this paper, we apply the Stackelberg game to the multi-layer network and comprehensively assess vulnerability based on game equilibrium to realize accurate protection. We first present a method for constructing a general model of the multi-layer network and introduce a multi-layer weighted factor to extend topological attribute metrics. Then, we design a Stackelberg game model for the multi-layer network. Furthermore, we qualitatively analyze the impact of multi-layer network characteristics on vulnerability and propose a method to quantify vulnerability. Experiments show that the vulnerability of the multi-layer network is greatly influenced by the multi-layer weighted factor, single-layer network type, and inter-layer coupling method. The quantitative value of network vulnerability does not rely entirely on the topology attributes on which the attack and defense costs depend but also relates to the resources available. Our work provides an adaptive model for CIS and gives a new approach to developing accurate protection based on comprehensive vulnerability assessment, which deserves further study.
A novel linear stability method based on Shakhov Bhatnagar–Gross–Krook equations for Rayleigh–Bénard convection in rarefied gases
Authors: Wu Chao , Bi Lin , Zhao Jin , Tang Zhigong , Yuan Xianxu , Wen Dongsheng
Published: December 2024

In light of the limitations of the traditional Navier–Stokes (NS) equations in rarefied gas flows, this paper proposes a flow stability analysis method based on Shakhov Bhatnagar–Gross–Krook (S-BGK) equations to investigate the instability of Rayleigh–Bénard convection in rarefied gases. The study explores the effects of the Knudsen number (Kn), the Froude number (Fr), the temperature ratio, and the Prandtl number (Pr) on flow stability. The results indicate that as Kn increases, the linear stability equations (LSEs) based on Navier–Stokes equations (NS-LSEs) tend to underestimate the growth rate. Analysis of the effects of Kn and Fr reveals that the most unstable mode transitions with changes in these parameters. In addition, the effects of temperature ratio and Pr on the stability present different trends: an increase in the temperature ratio stabilizes the flow, whereas an increase in Pr destabilizes it.
A transition edge sensor operated in coincidence with a high sensitivity athermal phonon sensor for photon coupled rare event searches
Authors: Romani R. K. , Chang Y.-Y. , Mahapatra R. , Platt M. , Reed M. , Rydstrom I. , Sadoulet B. , Serfass B. , Pyle M.
Published: December 2024

Experimental searches for axions or dark photons that couple to the standard model photon require photosensors with low noise, broadband sensitivity, and near zero backgrounds. Here, we introduce an experimental architecture, in which a small photon sensor, in our case a transition edge sensor (TES) with a photon energy resolution σγ=368.4±0.4 meV, is colocated on the same substrate as a large high sensitivity athermal phonon sensor (APS) with a phonon energy resolution σphonon=701±2 meV. We show that single 3.061 eV photons absorbed in the photon-sensing TES deposit ∼35% of their energy in the electronic system of the TES, while ∼26% of the photon energy leaks out of the photon-sensing TES during the downconversion process and becomes absorbed by the APS. Backgrounds, which we associate with the broadly observed “low energy excess” (LEE), are observed to be largely coupled to either the TES (“singles” LEE), or phonon system, (“shared” LEE). At high energies, these backgrounds can be efficiently discriminated from TES photon absorption events, while at low energies, their misidentification as photon events is well modeled. With significant sensitivity improvements to both the TES and APS, this coincidence technique could be used to suppress backgrounds in bosonic dark matter searches down to energies near the superconducting bandgap of the sensor.
An opportunity for streamlined computational fluid dynamics integration via a semi-analytical method for weighted finite volume fragmentation equations
Authors: Yadav Sarita , Wadhwa Deesha , Singh Mehakpreet , Kumar Jitendra
Published: December 2024

Over the past decade, finite volume schemes have significantly advanced, becoming well-regarded for solving linear and nonlinear population balance equations (PBEs). These schemes are highly accurate and efficient, making them ideal for applications like liquid–liquid dispersion, bubble and droplet fragmentation, in the chemical and pharmaceutical industries. Solving PBEs in continuous form remains challenging, particularly with complex fragmentation kernels and selection functions. Typically, these problems are tackled by forming discretized ordinary differential equations, with accuracy depending on the mesh type and cell count. To address these challenges, a new semi-analytical approach for solving the weighted finite volume scheme breakage equations has been developed [Kumar et al. (2015), “Development and convergence analysis of a finite volume scheme for solving breakage equation,” SIAM J. Numer. Anal. 53(4), 1672–1689]. This approach can replace traditional numerical schemes using the fourth order Runge-Kutta method. The mesh-independence with respect to time of finite volume schemes allows efficient coupling with computational fluid dynamics (CFD) tools. The accuracy and efficiency of the proposed method have been validated with analytically tractable and physically relevant fragmentation kernels and selection functions, demonstrating high accuracy in estimating number density functions and their integral moments. This new approach reduces computational time by approximately 60%, making it an excellent option for integration with CFD software due to its efficiency.
Numerical research of unsteady forces induced by turbulence inflow for propeller
Authors: Hu Jian , Li Xusheng , Ning Xiaoshen , Zhang Weipeng , Wan Qingyuan , Wang Zibin
Published: December 2024

In this work, the unsteady force response of non-cavitation propeller is analyzed. Numerical simulation is carried out using large-eddy simulation on the hydrodynamic performance of a ten-blade propeller. Different grid-propeller models are established, and the influence of turbulent flow conditions and skew angle on propeller unsteady force is studied. Results show that both turbulence intensity and turbulence length scale affect unsteady propeller force, which is mainly reflected in the broadband part of unsteady propeller force. In addition, the load distribution on the blade surface changes with the increase in the skew angle, which also changes the unsteady force performance of the propeller.
Initial coalescence between a drop and a liquid pool: A lattice Boltzmann investigation validated by experiments
Authors: Collignon E. , Zhang Q. D. , Frank X. , Li Huai Z.
Published: December 2024

We present a numerical investigation of the coalescence of a drop with a pool of the same liquid. The simulations were carried out with both viscous Newtonian and viscoelastic fluids based on an axisymmetric high density ratio lattice Boltzmann method with a diffuse interface coupled with the Oldroyd-B Model. Particular attention was paid to the widening dynamics of the liquid bridge between the drop and the pool and to the velocity fields within both the drop and liquid bulk. The results were compared with experimental data obtained using a high-speed camera and a micro-particle image velocimetry (μ-PIV) and displayed satisfactory agreement. In particular, the simulated temporary evolution of the rescaled coalescing width of the liquid bridge as a function of the normalized time compares favorably with the experimental results for both the inertially limited viscous and the inertial regimes for short and long time.
Exploration of refrigerant vapor–lubricating oil two-phase flow in a scroll compressor
Authors: Hong Jiahua , He Xiaoxi , Sun Chang , Zhang Dongsheng , Tao Wenquan
Published: December 2024

Precise information about the oil discharge rate (ODR) of a compressor and the oil retention rate (ORR) in the oil sump is essential for compressor design, development, and operation. An extended two-fluid model (E–TFM) is developed to study the complicated refrigerant vapor–lubricating oil two-phase flow inside a compressor. Gas–liquid bubbly, droplet, and well-mixed flows are defined on the local cell scale in the E–TFM. Numerical simulations are conducted to investigate the oil–vapor flow field and predict the ODR and ORR of a scroll compressor. The ODR predictions given by the volume-of-fluid method, the conventional Euler–Euler model, and the E–TFM are compared and validated against available measured data. The results confirm the reliability and applicability of the E–TFM. Most oil droplets escaping from the discharge pipe are found to originate from the newly generated droplets via stripping and breakage of the down-flowing thin oil film in the middle cavity. The droplet diameter significantly influences the predicted ODR, whereas the termination criterion for gas–liquid bubbly flow has little effect on the predicted ODR or flow field over the range considered in this study. To improve the ODR prediction performance of E–TFM, efforts should be made to implement a population balance equation to capture the droplet size.
Bifurcations in the Kuramoto model with external forcing and higher-order interactions
Authors: Costa Guilherme S. , Novaes Marcel , de Aguiar Marcus A. M.
Published: December 2024

Synchronization is an important phenomenon in a wide variety of systems comprising interacting oscillatory units, whether natural (like neurons, biochemical reactions, and cardiac cells) or artificial (like metronomes, power grids, and Josephson junctions). The Kuramoto model provides a simple description of these systems and has been useful in their mathematical exploration. Here, we investigate this model by combining two common features that have been observed in many systems: External periodic forcing and higher-order interactions among the elements. We show that the combination of these ingredients leads to a very rich bifurcation scenario that produces 11 different asymptotic states of the system, with competition between forced and spontaneous synchronization. We found, in particular, that saddle-node, Hopf, and homoclinic manifolds are duplicated in regions of parameter space where the unforced system displays bi-stability.