bluuebunny/crossref_metadata_2025 huggingface dataset:
Single atom alloy clusters Agn−1X− (X = Cu, Au; n = 7–20) reacting with O2: Symmetry-adapted orbital model
Authors: Du Qiuying , Huang Lulu , Fu Jiaqi , Cao Yongjun , Xing Xiaopeng , Zhao Jijun
Published: December 2022

Single atom alloy AgCu catalysts have attracted great attention, since doping the single Cu atom introduces narrow free-atom-like Cu 3d states in the electronic structure. These peculiar electronic states can reduce the activation energies in some reactions and offer valuable guidelines for improving catalytic performance. However, the geometric tuning effect of single Cu atoms in Ag catalysts and the structure–activity relationship of AgCu catalysts remain unclear. Here, we prepared well-resolved pristine Agn− as well as single atom alloy Agn−1Cu− and Agn−1Au− (n = 7–20) clusters and investigated their reactivity with O2. We found that replacing an Ag atom in Agn− (n = 15–18) with a Cu atom significantly increases the reactivity with O2, while replacement of an Ag with an Au atom has negligible effects. The adsorption of O2 on Agn− or Agn−1Cu− clusters follows the single electron transfer mechanism, in which the cluster activity is dependent on two descriptors, the energy level of α-HOMO (strong correlation) and the α-HOMO–LUMO gap (weak correlation). Our calculation demonstrated that the cluster arrangements caused by single Cu atom alloying would affect the above activity descriptors and, therefore, regulates clusters’ chemical activity. In addition, the observed reactivity of clusters in the representative sizes with n = 17–19 can also be interpreted using the symmetry-adapted orbital model. Our work provides meaningful information to understand the chemical activities of related single-atom-alloy catalysts.
UV–Vis photodetector based on ionic liquid-modified perovskite–ZnO composite
Authors: Peng Yanyan , Jiang Dayong , Zhao Man
Published: December 2022

Photodetectors (PDs) that combine inorganic semiconductors with organic lead halide perovskites to produce broader spectral responses have captured great interest from researchers; however, the imperfect perovskite crystallinity and the defects on the film surface are still the main factors inhibiting the PD's capability. Here, we proposed a simple method by introducing ionic liquid [1-butyl-3-methylimidazolium iodide (BMII)] into ZnO/CH3NH3PbI3 to encourage the growth of perovskite grains, raise the crystallinity of perovskite, and reduce the trap states, finally enhancing the photoelectric performances. After the addition of BMII, there are 171-fold, 74-fold, and 76-fold increases, respectively, in the light–dark current ratio, the spectral responsivity, and the external quantum efficiency, meanwhile, detectivity can reach 2.58 × 1013 Jones in the UV–vis range. The impressive results can be owed to the higher carrier concentration of ZnO/CH3NH3PbI3 with BMII, which can facilitate the charge transfer and suppress the recombination of photogenerated carriers. This study may be of assistance to extend our knowledge of developing high-performance PDs.
Bonding and antibonding characters of the first order reduced density matrix. A new look at two charge-shift bonds
Authors: Hernández-Lechuga Karem , Hernández-Pérez Julio-Manuel , Hô Minhhuy
Published: December 2022

This article reports a new way of analyzing chemical bonds based on the use of gradient of a first order reduced density matrix (1-RDM) map to partition bonds into atomic core, valence, and dorsal regions that can be further characterized as bonding or antibonding. These classifications are directly related to the familiar language of molecular orbital analysis. Analyses based on these quantities and the critical points of the 1-RDM performed on two charge-shift bonds show that although they share common features, there are fundamental differences in these interactions that are detected neither by density-based analysis nor by valence bond theory. The results suggest the gradient of 1-RDM as a valuable tool in bond analysis.
Consequences of fear effect and prey refuge on the Turing patterns in a delayed predator–prey system
Authors: Anshu  , Dubey Balram , Kumar Sasmal Sourav , Sudarshan Anand
Published: December 2022

This study presents a qualitative analysis of a modified Leslie–Gower prey–predator model with fear effect and prey refuge in the presence of diffusion and time delay. For the non-delayed temporal system, we examined the dissipativeness and persistence of the solutions. The existence of equilibria and stability analysis is performed to comprehend the complex behavior of the proposed model. Bifurcation of codimension-1, such as Hopf-bifurcation and saddle-node, is investigated. In addition, it is observed that increasing the strength of fear may induce periodic oscillations, and a higher value of fear may lead to the extinction of prey species. The system shows a bistability attribute involving two stable equilibria. The impact of providing spatial refuge to the prey population is also examined. We noticed that prey refuge benefits both species up to a specific threshold value beyond which it turns detrimental to predator species. For the non-spatial delayed system, the direction and stability of Hopf-bifurcation are investigated with the help of the center manifold theorem and normal form theory. We noticed that increasing the delay parameter may destabilize the system by producing periodic oscillations. For the spatiotemporal system, we derived the analytical conditions for Turing instability. We investigated the pattern dynamics driven by self-diffusion. The biological significance of various Turing patterns, such as cold spots, stripes, hot spots, and organic labyrinth, is examined. We analyzed the criterion for Hopf-bifurcation for the delayed spatiotemporal system. The impact of fear response delay on spatial patterns is investigated. Numerical simulations are illustrated to corroborate the analytical findings.
Polyvinyl chloride cooperates with biomass to assist in the directional conversion of N and Cl as NH3 and HCl to prepare clean fuel by low-temperature microwave heating
Authors: Liu Zhen , Li Meining , Gong Shiyu , Wu Qiyao , Yin Ke , Du Chengyuan , Wang Zichen , Yuan Yue
Published: December 2022

This work proposed an innovative integrated process to produce clean fuel. Waste polyvinyl chloride (PVC) was co-pyrolysis with biomass as a hydrogenation agent to enhance the conversion N of biomass to NH3 in the gaseous product by microwave heating. This work demonstrated the conditions suitable for the co-pyrolysis of PVC and the biomass (straw and rice husk, respectively) process based on the denitrification and dechlorination effects including indexes of N and Cl removal ratio and NH3 and HCl production ratio. The mass ratio of PVC to biomass (PVC: biomass), microwave heating power, active carbon (AC), and the pyrolysis temperature turned out to be significant factors for N and Cl removal and PVC: biomass and AC were also positive for converting N and Cl to NH3 and HCl. The optimum operating conditions were PVC: biomass 1:9, microwave heating power 500 W, active carbon 1.6 g, and heating temperature 300 °C. The mechanism could be primarily related to the volumetric and selective heating advantage of microwave heating, being attributed to producing abundant H radicals from PVC and promoting the hydrogenation reaction of biomass to remove N as NH3. Moreover, the denitrification and dechlorination effect differences between microwave heating and electric heating were studied to explore the microwave non-thermal heating effect. The amount of the N removal ratio and the NH3 production ratio by microwave heating was almost 5%–10% higher. The amount of the Cl removal ratio and the HCl production ratio was almost 10% and 7% higher than that by electric heating. The pyrolysis reaction enhancement and the better denitrification and dechlorination effect of microwave heating could be a result of specific microwave non-thermal effects in addition to the thermal effect, containing more uniform heat distribution and selective heating characteristics. The present work may provide a new viewpoint for the clean utilization of biomass and chlorinated plastic waste as a fuel and avoid HCl corrosion when treating the chlorinated plastic waste.
Entropy scaling of viscosity for molecular models of molten salts
Authors: Young Jeffrey M. , Bell Ian H. , Harvey Allan H.
Published: December 2022

Entropy scaling relates dynamic and thermodynamic properties by reducing the viscosity to a function of only the residual entropy. Molecular simulations are used to investigate the entropy scaling of the viscosity of three models of sodium chloride and five monovalent salts. Even though the correlation between the potential energy and the virial is weak, entropy scaling applies at liquid densities for all models and salts investigated. At lower densities, entropy scaling breaks down due to the formation of ion pairs and chains. Entropy scaling can be used to develop more extendable correlations for the dynamic properties of molten salts.
Hyperthermia temperature reduction in biomagnetic flow: Thermal transfer in Fe3O4–blood particle suspension with uniform and non-uniform effects
Authors: Faruk M. H. , Ferdows M. , Tzirtzilakis E. E.
Published: December 2022

Magnetic hyperthermia is beneficial in cancer treatment and in the treatment of some blood vessel diseases. However, excessive temperatures may also kill healthy cells in the vicinity of a sick cell. Using magnetic nanoparticles and changing the nature of the magnetic field as required, magnetic hyperthermia may be regulated in the blood. This research examines the effects of uniform and non-uniform magnetic fields on suspensions of bio-magnetic fluid and nano-bio-magnetic fluid under hyperthermia. Blood is a diamagnetic material, and when combined with superparamagnetic Fe3O4, its thermo-mechanical characteristics are changed significantly. By manipulating the nature of the magnetic field, it is possible to raise or decrease the temperature in the flow domain of magnetic nano-fluids. A computational study of two such magnetic fields has been conducted, and their effects on the blood-based magneto nano-fluid flow in a rectangular conduit have been documented in this study using COMSOL multi-physics. Results indicate that a uniform magnetic field increases temperature only locally, but decreases the overall temperature in the domain. The non-uniform field of a current-carrying wire decreases both the local maximum and average blood temperature as field strength increases.
Charging a electrochemical double layer supercapacitor exhibiting a distribution of relaxation times
Authors: Helseth L. E.
Published: December 2022

A charging electrochemical double layer supercapacitor can usually be described by a single capacitance and a single resistance in parallel, wherein the latter represents the ohmic losses. Such an ideal behavior may occur if the supercapacitor consists of self-similar porous carbon micro- and nanostructures. However, if the electrochemical double layer supercapacitor consists of a sequence of slices with different relaxation times, a strong deviation from ideal charging curves may occur. Here, it is demonstrated how such charging curves can be interpreted in terms of a distribution of relaxation times. It is found that in the presence of a broad distribution of charge transfer resistances, the voltage initially appears to increase faster than normal during galvanostatic charging. Care should be taken to avoid misinterpretation of the capacitance under such circumstances.
The influence of Al2O3 nanolamination in ALD ZrO2 capacitor on physical and electrical characteristics
Authors: Guillon Virgil , Riou Benoit , Billoué Jérôme , Defforge Thomas , Gardes Pascal , Bah Micka , Gautier Gaël
Published: December 2022

In this paper, the nanolamination of a ZrO2 insulator by Al2O3 for metal insulator metal capacitor applications has been studied. The insulating layers (ZrO2 and Al2O3) were deposited by atomic layer deposition and the electrodes were made of TiN. Different configurations of ZrO2 and Al2O3 alternations were studied, including 1 to 16 Al2O3 inclusions in the ZrO2 layer. X-ray diffraction of the insulator configurations showed that with four or more Al2O3 inclusions, the structure loses its crystalline orientation and becomes amorphous. Electrical characterizations have been conducted to study the capacitance, breakdown field, and leakage current for every insulator configuration. The capacitance density significantly decreases as the number of Al2O3 layers increases, except when an amorphous transition occurs; at this point, a local maximum of 17 nF/mm2 was found. A 19% increase of the breakdown field of samples with two or more Al2O3 inclusions has been correlated with an increase of leakage current explained by the emergence of the Fowler–Nordeim conduction mechanism at electrical fields higher than 4 MV/cm.
Positronium chemistry of a Fe2+/3+ solution under electrochemical control
Authors: Brunner Philipp , Steyskal Eva-Maria , Topolovec Stefan , Würschum Roland
Published: December 2022

The positronium chemistry of a Fe2+/3+ solution is studied under full electrochemical control. For this novel approach to positronium electrochemistry, a suitable cell setup is used, which allows simultaneously both electrochemical measurements and positron annihilation spectroscopy. For the Fe2+/3+ redox couple, positronium serves as an ideally suited atomic probe owing to the rather different positronium chemistry of Fe2+ (spin conversion) and Fe3+ (total positronium inhibition and oxidation). This enabled the precise in situ monitoring of oxidation and reduction by means of positron lifetime upon slow cycling voltammetry or galvanostatic charging. The variation of the mean positron lifetime with the Fe2+/3+ concentration ratio could be quantitatively described by a reaction rate model for positronium formation and annihilation. An asymmetric behavior of the variation of the mean positron lifetime with applied potential, as compared to the simultaneously recorded symmetric current–potential curve, could be explained by the stronger influence of Fe3+ on the characteristics of positronium formation and annihilation. The highly reversible galvanostatic charging behavior monitored by positron lifetime underlines the attractive application potentials of positronium electrochemistry for in situ studies of iron-based redox-flow battery electrolytes.
Phenotyping of rare circulating cells in the blood of non-metastatic breast cancer patients using microfluidic Labyrinth technology
Authors: Pore Adity A. , Bithi Swastika S. , Zeinali Mina , Navaid Hunaiz Bin , Nagrath Sunitha , Layeequr Rahman Rakhshanda , Vanapalli Siva A.
Published: December 2022

Label-free technologies for isolating rare circulating cells in breast cancer patients are widely available; however, they are mostly validated on metastatic patient blood samples. Given the need to use blood-based biomarkers to inform on disease progression and treatment decisions, it is important to validate these technologies in non-metastatic patient blood samples. In this study, we specifically focus on a recently established label-free microfluidic technology Labyrinth and assess its capabilities to phenotype a variety of rare circulating tumor cells indicative of epithelial-to-mesenchymal transition as well as cancer-associated macrophage-like (CAML) cells. We specifically chose a patient cohort that is non-metastatic and selected to undergo neoadjuvant chemotherapy to assess the performance of the Labyrinth technology. We enrolled 21 treatment naïve non-metastatic breast cancer patients of various disease stages. Our results indicate that (i) Labyrinth microfluidic technology is successfully able to isolate different phenotypes of CTCs despite the counts being low. (ii) Invasive phenotypes of CTCs such as transitioning CTCs and mesenchymal CTCs were found to be present in high numbers in stage III patients as compared to stage II patients. (iii) As the total load of CTCs increased, the mesenchymal CTCs were found to be increasing. (iv) Labyrinth was able to isolate CAMLs with the counts being higher in stage III patients as compared to stage II patients. Our study demonstrates the ability of the Labyrinth microfluidic technology to isolate rare cancer-associated cells from the blood of treatment naïve non-metastatic breast cancer patients, laying the foundation for tracking oncogenic spread and immune response in patients undergoing neoadjuvant chemotherapy.
Ultrasensitive detection of SARS-CoV-2 S protein with aptamers biosensor based on surface-enhanced Raman scattering
Authors: Gu Man-Man , Guan Peng-Cheng , Xu Shan-Shan , Li Hong-Mei , Kou Yi-Chuan , Lin Xiao-Dong , Kathiresan Murugavel , Song Yanling , Zhang Yue-Jiao , Jin Shang-Zhong , Li Jian-Feng
Published: December 2022

A rapid and accurate diagnostic modality is essential to prevent the spread of SARS-CoV-2. In this study, we proposed a SARS-CoV-2 detection sensor based on surface-enhanced Raman scattering (SERS) to achieve rapid and ultrasensitive detection. The sensor utilized spike protein deoxyribonucleic acid aptamers with strong affinity as the recognition entity to achieve high specificity. The spherical cocktail aptamers-gold nanoparticles (SCAP) SERS substrate was used as the base and Au nanoparticles modified with the Raman reporter molecule that resonates with the excitation light and spike protein aptamers were used as the SERS nanoprobe. The SCAP substrate and SERS nanoprobes were used to target and capture the SARS-CoV-2 S protein to form a sandwich structure on the Au film substrate, which can generate ultra-strong “hot spots” to achieve ultrasensitive detection. Analysis of SARS-CoV-2 S protein was performed by monitoring changes in SERS peak intensity on a SCAP SERS substrate-based detection platform. This assay detects S protein with a LOD of less than 0.7 fg mL−1 and pseudovirus as low as 0.8 TU mL−1 in about 12 min. The results of the simulated oropharyngeal swab system in this study indicated the possibility of it being used for clinical detection, providing a potential option for rapid and accurate diagnosis and more effective control of SARS-CoV-2 transmission.
Electronic and magnetic structure of ultrathin Co9Se8 nanosheets and Co9Se8 bulk from density functional theory calculations
Authors: van Gog Heleen
Published: December 2022

Two-dimensional transition-metal chalcogenides are one of the most interesting new classes of 2D materials. 2D cobalt selenide nanomaterials are being actively pursued and investigated as well, and recently, the first large-scale synthesis of half-unit-cell-thick Co9Se8 nanosheets has been reported. In the present study, using density functional theory calculations and employing the advanced hybrid HSE06 exchange-correlation functional, the electronic and magnetic structure of Co9Se8 nanosheets is investigated. To allow a comparison with bulk, the electronic and magnetic properties of Co9Se8 bulk are investigated as well. The bulk phase is found to be a ferrimagnetic semiconductor. Reducing the dimensions of Co9Se8 bulk to form a half-unit-cell-thick Co9Se8 nanosheet strongly alters the electronic and magnetic structure of the material. The nanosheet is predicted to have a different type of ferrimagnetic ordering and to be a metal with semimetallic features. Analysis of the X–M segment of the nanosheet's band structure, which mainly determines the electronic transport properties of the material, shows that within this segment, the main band below the Fermi level consists of only spin-up states (Se 4p), while the main band above the Fermi level consists of only spin-down states (Se 4p hybridized with Co 3d). This combination points to possibilities of selective conductivity of either spin-up or spin-down electrons and indicates that ultrathin Co9Se8 nanosheets are a most promising candidate for nanoelectronic and spintronic applications.
Low-frequency anharmonic couplings in crystalline bromoform: Theory
Authors: Sertcan Beliz , Mousavi Seyyed Jabbar , Iannuzzi Marcella , Hamm Peter
Published: December 2022

Theoretical calculations of the low-frequency anharmonic couplings of the β-phase of crystalline bromoform are presented based on density functional theory quantum chemistry calculations. The electrical and mechanical anharmonicities between intra- and intermolecular modes are calculated, revealing that the electrical anharmonicity dominates the cross-peak intensities in the 2D Raman–THz response and crystalline, as well as liquid, bromoform. Furthermore, the experimentally observed difference in relative cross-peak intensities between the two intramolecular modes of bromoform and the intermolecular modes can be explained by the C3v-symmetry of bromoform in combination with orientational averaging. The good agreement with the experimental results provides further evidence for our interpretation that the 2D Raman–THz response of bromoform is, indeed, related to the anharmonic coupling between the intra- and intermolecular modes.
Passive control of vortex-shedding past finite cylinders under the effect of a free surface
Authors: Carvalho I. A. , Assi G. R. S.
Published: December 2022

Passive technologies for the control of the flow past bluff bodies have been widely studied. Most of these works have focused on high-aspect-ratio, wall-mounted, or infinitely long cylinders, leaving a gap for low-aspect-ratio bodies fully submerged or under the effect of a free water surface. This is the object of the present work. Detached-eddy simulations at a Reynolds number of 1000 have been carried out for infinitely long (case i) and low-aspect-ratio bodies. For the finite case, two configurations were investigated: bodies fully submerged in the flow, away from surface effects (case ii) and that involving a free surface, here represented by a fixed slip-allowing plane (case iii). These computations were conducted for the bare cylinder and the system is comprised of the same main body fitted with eight wake-control rods uniformly distributed around its perimeter. Results showed that the low-aspect-ratio cases relative to infinitely long structures (1) lowered mean drag and root mean square lift, (2) presented a less coherent wake topology, (3) had frontal rods that concentrated most of the hydrodynamic loads, (4) extended the formation length, and (5) although all cases developed larger hydrodynamic loads when the rods were fitted to the main body compared to the plain cylinder, the finite cases produced a lower increase. We show that these results are intrinsically related to end effects and associated with a less correlated wake lacking coherent vortical structures. Furthermore, we analyze the more accentuated streamwise vortices produced by the presence of the free surface in case iii compared with case ii.
Eye in the sky: observing wild dingo hunting behaviour using drones
Authors: Pollock Tahlia I. , Hunter Daniel O. , Hocking David P. , Evans Alistair R.
Published: December 2022

Context The behaviours used by mammalian predators to track, kill, and consume prey are some of the most dynamic interspecific interactions in nature. However, they are often challenging to follow through the landscape and observe directly without disturbing the animals being watched. Aims We describe the behaviours used by wild dingoes while hunting macropods in Namadgi National Park, Australian Capital Territory, Australia. Methods Footage was initially captured by wildlife cinematographers on behalf of documentary programs and was made available for viewing after production. Hunting events were filmed from an altitude of >50 m by using a ‘long lens’ fitted to either a drone or helicopter. Results We recorded a suite of hunting behaviours that would have been extremely challenging to observe from the ground via traditional methods. This includes some of the first video records published in the scientific literature of the behaviours used by dingoes to hunt and kill macropod prey, as well as some rare observations of mother and pup hunting dynamics. We did not observe any signs of disturbance as a result of filming for either predator or prey. Conclusions The varied repertoire of predatory behaviours displayed by dingoes is similar to that documented in wolves and asserts them as a behaviourally complex top predator in the Australian landscape. In addition, we highlight the use of drones as a valuable approach for directly observing wild behaviours. They offer a minimally invasive and relatively inexpensive and accessible alternative to helicopters. This project is also a case study exemplifying the value of collaborations between filmmakers and researchers that enable the sharing of archival documentary footage for the study of wild animal behaviour. Implications Future studies of wild animal behaviour should consider employing drones (at a safe distance and in accordance with published best practices and guidelines) as an additional tool to collect types of data that would be challenging using other methods.
Kinesin-1 autoinhibition facilitates the initiation of dynein cargo transport
Authors: Qiu Rongde , Zhang Jun , Xiang Xin
Published: December 2022

The functional significance of Kinesin-1 autoinhibition has been unclear. Kinesin-1 transports multiple cargoes including cytoplasmic dynein to microtubule plus ends. From a genetic screen for Aspergillus mutants defective in dynein-mediated early endosome transport, we identified a kinesin-1 mutation kinAK895* at the C-terminal IAK motif involved in autoinhibition. The kinA∆IAK and kinAK895E mutants exhibited a similar defect in dynein-mediated early endosome transport, verifying the importance of kinesin-1 autoinhibition in dynein-mediated transport. Kinesin-1 autoinhibition is not critical for dynein accumulation at microtubule plus ends or for the secretory vesicle cargoes of kinesin-1 to reach the hyphal tip. However, it facilitates dynein to initiate early endosome transport. This is unrelated to a direct competition between dynein and kinesin-1 on early endosomes because kinesin-3 rather than kinesin-1 drives the plus-end-directed early endosome movement. This effect of kinesin-1 autoinhibition on dynein-mediated early endosome transport is related to cargo adapter-mediated dynein activation but at a step beyond the switching of dynein from its autoinhibited conformation.
Cilia bent out of shape over dysfunctional astrocyte mitochondria
Authors: Bear Rachel M. , Caspary Tamara
Published: December 2022

Mitochondrial dysfunction in astrocytes drives neurodegenerative brain pathology. In this issue, Ignatenko et al. (2022. J. Cell. Biol.https://doi.org/10.1083/jcb.202203019) discover a novel connection between cilia and mitochondria in astrocytes, whereby mitochondrial dysfunction leads to abnormal cilia structure and a motile cilia program.
Calcium activation through thick and thin?
Authors: Previs Michael J.
Published: December 2022

A historical perspective of the super-relaxed (SRX) state, interacting heads motif (IHM), and impact of calcium on muscle contractility.
Near thermal-electric field controlled electrohydrodynamic 3D printing of high aspect ratio microstructures
Authors: Li Dongya , Hong Haodong , Sun Xinhu , Zhang Yang , Liu Yu
Published: December 2022

Electrohydrodynamic (EHD) printing is an effective method for high-resolution two-dimensional patterning because of its high material compatibility. The latest research on three-dimensional (3D) structure fabrication has been reported for metal nanoparticles, small molecular materials, and phase change materials by process regulation. One of the main challenges in conventional EHD 3D printing of polymers is the low accuracy of filament deposition and stacking at the microscale. It is difficult to achieve a high aspect ratio (AR) for printed structures. This study develops an external field-assisted EHD printing process for polymer materials, where the filament formation can be improved by the near thermal field and the stacking accuracy of filaments is further promoted by applying an alternating voltage between layers. The feasibility of this method is demonstrated by printing polystyrene, a typical polymer material, on the silicon substrate with. The regulatory effect of the process parameters on the filament width is explored. The influence of the external thermal field on filament formation and deposition is discussed, and a promotion mechanism is revealed of alternating voltage for accurate deposition. Based on these combinative effects, micro-scale 3D structures with a high AR are successfully printed on the insulating substrate with three kinds of polymers.
Theoretical study of low energy electron collisions with the BeO molecule
Authors: Mukherjee N , Chakrabarti K
Published: December 2022

An R-matrix calculation is reported for low energy electron collision with the beryllium oxide (BeO) molecule at its equilibrium bond length

R

e

=
2.515

a
0 for incident energies below 15 eV. Using a suitably constructed model to represent the BeO target, detailed scattering calculations are performed to obtain cross sections for many collision processes, namely total cross sections for elastic scattering and electronic excitations to some of its low lying states and cross section for electron impact dissociation. Additionally, we have also calculated differential cross sections for electronic excitations from the X

1

Σ
+

ground state to the first two excited states of the target BeO molecule. BeO is likely to be present as an impurity component in the plasma of fusion devices operating with beryllium as first wall material. We therefore expect the present study to be of substantial importance to the fusion community.
Investigation of the diameter-dependent piezoelectric response of semiconducting ZnO nanowires by Piezoresponse Force Microscopy and FEM simulations
Authors: Jalabert Thomas , Pusty Manojit , Mouis Mireille , Ardila Gustavo
Published: December 2022

Semiconducting piezoelectric nanowires (NWs) are promising candidates to develop highly efficient mechanical energy transducers made of biocompatible and non-critical materials. The increasing interest in mechanical energy harvesting makes the investigation of the competition between piezoelectricity, free carrier screening and depletion in semiconducting NWs essential. To date, this topic has been scarcely investigated because of the experimental challenges raised by the characterization of the direct piezoelectric effect in these nanostructures. Here we get rid of these limitations using the piezoresponse force microscopy technique in DataCube mode and measuring the effective piezoelectric coefficient through the converse piezoelectric effect. We demonstrate a sharp increase in the effective piezoelectric coefficient of vertically aligned ZnO NWs as their radius decreases. We also present a numerical model which quantitatively explains this behavior by taking into account both the dopants and the surface traps. These results have a strong impact on the characterization and optimization of mechanical energy transducers based on vertically aligned semiconducting NWs.
Strain and charge contributions to the magnetoelectric coupling in Fe3O4/PMN-PT artificial multiferroic heterostructures
Authors: Schöffmann Patrick , Sarkar Anirban , Hussein Hamed Mai , Bhatnagar-Schöffmann Tanvi , Pütter Sabine , Kirby Brian J , Grutter Alexander J , Barthel Juri , Kentzinger Emmanuel , Stellhorn Annika , Gloskovskii Andrei , Müller Martina , Brückel Thomas
Published: December 2022

The quest to realize new kinds of data storage devices has motivated recent studies in the field of magnetoelectric heterostructures. One of the most commonly investigated systems is Fe3O4/[Pb(Mg

1

/

3

Nb

2

/

3

)

O3]0.7–[PbTiO3]0.3 (PMN-PT), however, the interplay between different coupling mechanisms is not yet well understood. To disentangle the role of strain and polarisation influence in Fe3O4/PMN-PT, we report on magnetoelectric coupling measurements for different orientations of the applied magnetic field and for two different substrate cuts, PMN-PT(001) and PMN-PT(011). For Fe3O4/PMN-PT(011), having the sample aligned such that the magnetic field is parallel to the [01

1
‾

] easy axis leads to a remanent increase of the magnetisation for each electric field cycle. On the other hand, for the magnetic field along the [100] hard axis, the magnetisation follows a butterfly-like loop characteristic of strain coupling imparted by the substrate. For Fe3O4/PMN-PT(001), the magnetoelectric effect is a superposition of the observed behaviour of both in-plane directions in Fe3O4/PMN-PT(011). The magnetisation shows an initial remanent increase followed by a butterfly like loop. Polarised neutron reflectometry measurements on Fe3O4/PMN-PT(011) shows no difference between the behaviour at the interface and the bulk of the film and no decline of the interaction further away from the shared interface. Our results demonstrate the role of strain and polarisation on the magnetisation of the Fe3O4 layer and provide a clear step towards the design of future magnetoelectric systems.
Analysis of displacement damage effects on the charge-coupled device induced by neutrons at Back-n in the China Spallation Neutron Source
Authors: Xue Yuan-Yuan , Wang Zu-Jun , Chen Wei , Guo Xiao-Qiang , Yao Zhi-Bin , He Bao-Ping , Nie Xu , Lai Shankun , Huang Gang , Sheng Jiang-Kun , Ma Wu-Ying , Gou Shi-Long
Published: December 2022

Displacement damage effects on the charge-coupled device (CCD) induced by neutrons at the back-streaming white neutron source (Back-n) in the China Spallation Neutron Source (CSNS) are analyzed according to an online irradiation experiment. The hot pixels, random telegraph signal (RTS), mean dark signal, dark current and dark signal non-uniformity (DSNU) induced by Back-n are presented. The dark current is calculated according to the mean dark signal at various integration times. The single-particle displacement damage and transient response are also observed based on the online measurement data. The trends of hot pixels, mean dark signal, DSNU and RTS degradation are related to the integration time and irradiation fluence. The mean dark signal, dark current and DSNU2 are nearly linear with neutron irradiation fluence when nearly all the pixels do not reach saturation. In addition, the mechanisms of the displacement damage effects on the CCD are demonstrated by combining the experimental results and technology computer-aided design (TCAD) simulation. Radiation-induced traps in the space charge region of the CCD will act as generation/recombination centers of electron–hole pairs, leading to an increase in the dark signal.
Runaway electron dynamics in Experimental Advanced Superconducting Tokamak helium plasmas
Authors: Luo Chen-Xi , Zeng Long , Zhu Xiang , Tang Tian , Qiu Zhi-Yong , Lin Shi-Yao , Zhang Tao , Liu Hai-Qing , Shi Tong-Hui , Zhang Bin , Ding Rui , Gao Wei , Wang Min-Rui , Gao Wei , Ti Ang , Zhao Hai-Lin , Zhou Tian-Fu , Qian Jin-Ping , Sun You-Wen , Lv Bo , Zang Qing , Jie Yin-Xian , Liang Yun-Feng , Gao Xiang
Published: December 2022

The generation of runaway electrons (REs) is observed during the low-density helium ohmic plasma discharge in the Experimental Advanced Superconducting Tokamak (EAST). The growth rate of hard x-ray (HXR) is inversely proportional to the line-average density. Besides, the RE generation in helium plasma is higher than that in deuterium plasma at the same density, which is obtained by comparing the growth rate of HXR with the same discharge conditions. The potential reason is the higher electron temperature of helium plasma in the same current and electron density plateau. Furthermore, two Alfvén eigenmodes driven by REs have been observed. The frequency evolution of the mode is not fully satisfied with the Alfvén scaling and when extension of the Alfvén frequency is towards 0, the high frequency branch is ∼50 kHz. The different spatial position of the two modes and the evolution of the helium concentration could be used to understand deviation between theoretical and experimental observation.
Turing pattern selection for a plant–wrack model with cross-diffusion
Authors: Sun Ying , Wang Jinliang , Li You , Jiang Nan , Xia Juandi
Published: December 2022

We investigate the Turing instability and pattern formation mechanism of a plant–wrack model with both self-diffusion and cross-diffusion terms. We first study the effect of self-diffusion on the stability of equilibrium. We then derive the conditions for the occurrence of the Turing patterns induced by cross-diffusion based on self-diffusion stability. Next, we analyze the pattern selection by using the amplitude equation and obtain the exact parameter ranges of different types of patterns, including stripe patterns, hexagonal patterns and mixed states. Finally, numerical simulations confirm the theoretical results.
Atomic optical spatial mode extractor for vector beams based on polarization-dependent absorption
Authors: Chang Hong , Yang Xin , Wang Jinwen , Ma Yan , Yang Xinqi , Cao Mingtao , Zhang Xiaofei , Gao Hong , Dong Ruifang , Zhang Shougang
Published: December 2022

Vector beams with spiral phase and spatially varying polarization profiles have many applications from optical micromanipulation to materials processing. Here, we propose and demonstrate an atomic spatial mode extracting scheme for the vector beam based on polarization-dependent absorption in the atom vapor. By employing the linear polarization pump beam which induces polarization sensitive absorption in the atomic ensemble, a counter-propagated weak probe vector beam is extracted by spatial absorption, and extracted part still maintains the original polarization and the vortex phase. The topological charges of the extracted mode are verified by interfering with the Gaussian beam, and it can be found that the orbital angular momentum is conserved in the extracting process. Our work will have potential applications in non-destructive spatial mode identification, and is also useful for studying higher-dimensional quantum information based on atomic ensembles.
Methods for efficiency evaluation of MX-1.8 GV cotton pickers in horizontal-spindle design
Authors: Matchanov R D , Yuldashev A T , Kuldoshev D A
Published: December 2022

The article is devoted to determining the economic profitability of MX-1.8 GV cotton pickers in comparison with handpicking. The article presents the results of field tests of a horizontal-spindle design of MX-1.8 GV cotton harvester performance, compared with the results of numerical studies obtained using a computer program. The results obtained were used to further determine the economic efficiency of machine harvesting. The costs of machine and handpicking are determined. On the basis of numerical studies, it was proved that machine harvesting using MX-1.8 GV cotton picker is economically profitable at an open crop yield of more than 2.75 t/ha.
Development and use of modern mobile applications for training
Authors: Volodina E V , Mikishanina E A
Published: December 2022

The article describes the development and introduction of a mobile application based on Android using Java programming language the educational process of students. An overview of applications for teaching the subject “Probability theory, mathematical statistics and random processes” and for teaching solving problems with parameters is given. The main stages of working on a mobile app are described in details, the advantages and disadvantages of the research are indicated.
Simulation of gaseous fuel jet combustion process in the OpenFOAM package
Authors: Kurbanaliev A Y , Kaleeva A K , Tattybubu Mars kyzy , Kalyskan Imatali kyzy , Teshebaeva U T
Published: December 2022

The general mathematical formulation of describing flows with chemical reactions problem includes mass conservation, momentum, energy and concentrations equations for each chemical substance, supplemented by the state equation and other thermodynamic relations. Chemical kinetics, through the heat of reactions, relates the concentrations of various substances to the energy equation. In many combustion systems, it is the chemical kinetics that determines the characteristic spatial and temporal scales of the equations to be solved. In this paper, we consider the problem of spray combustion of gaseous simple hydrocarbon fuel in a cylindrical channel. Mathematical modeling was carried out within the framework of the open package OpenFOAMv7, and the visualization of numerical results was carried out using Paraview 5.6. Deep understanding and tuning of a simple gaseous reaction scheme in the OpenFOAM package when modeling reacting flows is the goal of this work. It is shown that the CFD package used makes it possible to successfully simulate this class of flows.
On the determination of stresses in the case of a plastic problem with an ellipsoidal cavity
Authors: Maksimov A N , Maksimova L A , Derevyanikh E A , Belova N N , Konstantinov Yu V , Mitrofanova T V
Published: December 2022

The material of the work is an integral element of the problem of determining the stress-strain state of various types of arrays, including various forms of recess. In the current problem, the stress state is determined in the plastic zone near an ellipsoidal recess for a compressible mass. There is no pressure inside the recess, and at a considerable distance there is compression by mutually perpendicular forces. A solution is obtained for the case of the first approximation by the small parameter method. The results can be applied in the field of structural mechanics, mining business, and other related fields.
An error analysis of a rheological study of magnetic nanofluids on a rotational viscometer
Authors: Bolotov A N , Novikov V V , Novikova O O
Published: December 2022

The paper considers metrological instrumentation for studying the rheological properties of magnetic fluids. It also presents the design of a magnetic coaxial viscometer. There is a metrological analysis of the factors that affect the measurement accuracy. Errors are systematized into 2 main groups: method and instrumental. The authors analyse the contribution of each group to the total metrological error. It is established that the temperature instability of the liquid under study and the error in determining the level of the liquid in contact with the measuring cylinder have the greatest effect on the measurement results. There is a theoretical assessment of the instrument error and its minimum value. The authors propose the main directions for improving the viscometer design. They also show the possibility of a significant reduce in the total measurement error by calibrating the device. There are comparative studies of experimental and reference liquids indicating good accuracy and reliability of experimental data.
Principles for optimizing the working process of a high-speed heat engine when converting it to a gas-liquid modification
Authors: Kazakov Y F , Alatyrev S S , Vasiliev A O , Maksimov I I , Pushkarenko N N , Likhanov V A , Rossokhin A V
Published: December 2022

Converting a compression-ignition thermal plant to gas-liquid operation is one way to neutralize the danger of waste while maintaining the high efficiency of the engine corresponding to the original modification. Although debugging the functioning of a gas-liquid installation is a significantly problematic task, since we are dealing with a large number of interrelated properties. Therefore, optimizing the injection of diesel fuel (DF)/methane by solving a problem with several unknowns was one of the goals of our research. More than 10 parameters must be taken into account for the modeling to be adequate, including the initial (flammable) DF injection. In our experiments, the volume of the ignition DF was determined to be optimal in the amount of 0.15...0.20 relative to the single-fuel modification, respectively, the duration of fuel injection changed proportionally.
Development of e-learning resources for distance learning in the field of radio engineering
Authors: Galkina A I , Grishan I A , Kleynosova N P , Orehvo D O , Khrunichev R V
Published: December 2022

The article presents the analysis of the results of electronic educational resources development in the field of “Radio Engineering”, registered by the authors of Ryazan State Radio Engineering University after V.F. Utkin in the United Foundation of Electronic Resources «Science and Education». Under epidemic constraints, the higher education system is faced with the need to provide distance or blended learning, with no loss of quality. The basis of distance learning consists of electronic educational resources of different formats, which allow providing information interaction of all participants of the educational process: students, teachers, administration. The object of research is electronic educational resources. The subject of the study is electronic educational resources in the field of radio engineering, developed at Ryazan State Radio Engineering University. The research methods are statistical, logical and semantic analysis methods. The information on electronic resources is selected from the database of the United Fund of Electronic Resources «Science and Education» for the period from 2019 to 2021. Statistical processing of database records is automated, carried out with the help of software developed by the specialists of the “Science and Education” pool of electronic resources.
Numerical simulation of a flat turbulent near-wall jet in the OpenFOAMv7 package
Authors: Kurbanaliev A Y , Abdimutalipova Z K , Aknazarova S S , Erkin Abdinabi uulu , Suyumkan Myktarbek kyzy
Published: December 2022

In this research, the numerical simulation of a planar stationary near-wall turbulent jet using the OpenFOAMv7 package at Reynolds number, Re, equal to 9600 has been performed. Comparison of numerical results with corresponding experimental data on longitudinal velocity profiles shows the adequacy of the used mathematical model of the problem under consideration. This model should be used in further studies of turbulent jet flows.
The specifics of teaching bachelors and masters in the field of applied physics and metrology
Authors: Yakovlev Valeriy A , Zakharova Diana V
Published: December 2022

At the official level, the profession of “Metrologist” appeared only a few decades ago. However, even now there is no doubt that this profession has a huge impact on the daily life of a person. The thing is that metrology one way or another affects most of the areas of human activity. The most common ruler, which every person is used to using on a daily basis, is also the result of the work of a metrologist. At the same time, it is quite difficult to find a metrologist specialist in the modern world, since not every person dares to get such a specialty. Although there is no doubt that metrologists are popular. And they have great career prospects! An engineer is a leading position, therefore this specialist is always familiar with the basic norms and rules of labor protection, as well as the basic provisions of the Labor Code of the Russian Federation. Within the framework of this article, the main features of a narrow profile specialization will be considered in more detail.
MOOC in physics as an additional resource for the fundamental training of would-be engineers
Authors: Liksina E V , Vagaeva O A , Galimullina N M , Efremkina I N , Dianova Y A
Published: December 2022

Physics is one of the key disciplines stipulated by the curricular of engineering majors. Despite a sufficient amount of academic hours dedicated to this discipline at schools and universities, it is necessary to expand the opportunities for applying additional learning tools, autonomous studies of the most important areas of physics. One of such tools is mass open online courses (MOOCs). The article analyzes open online courses in physics provided by foreign (Coursera and EdX) and Russian (Open Education and Stepik) platforms. The criteria for analysis were the courses duration, the required level of training, the scope and content, as well as the features of pedagogical design of the courses. The demand for courses (number of learners), the universities developing them and the language of teaching were also taken into account.