bluuebunny/crossref_metadata_2025 huggingface dataset:
The role of mechanobiology in bone and cartilage model systems in characterizing initiation and progression of osteoarthritis
Authors: Hodgkinson Tom , Amado Isabel N. , O'Brien Fergal J. , Kennedy Oran D.
Published: January 2022

Multifaceted changes in the mechanobiological environment of skeletal joints, at multiple length scales, are central to the development of diseases-like osteoarthritis (OA). Recent evidence demonstrates related mechanical alterations in both bone and cartilage tissues, with crosstalk between the tissues being an important factor in acute and chronic degenerative processes. However, recapitulating multicellular tissue systems in the laboratory to study the entire osteochondral unit remains challenging. Thus, the development of accurate and reproducible OA model systems and the selection of the most suitable model for individual experimental approaches are critical. This review first discusses recent progress in understanding mechanosensory processes in healthy and osteoarthritic joints. Subsequently, we review advancements in the development of in vitro and ex vivo model systems ranging from 2D monocultures through to joint organ-on-a-chip models. Use of these systems allows for the study of multiple cell types in controlled, reproducible, and dynamic environments, which can incorporate precisely controlled mechanical and biochemical stimuli, and biophysical cues. The way in which these models have, and will continue to, improve our ability to recapitulate complex mechanical/paracrine signaling pathways in osteochondral tissues is then discussed. As the accuracy of model systems advances, they will have a significant impact on both our understanding of the pathobiology of OA and in identifying and screening therapeutic targets to improve treatment of this complex disease.
An ultra-low background alpha detection system with a Micromegas-based time projection chamber
Authors: Pan Jiang , Zhang Zhiyong , Feng Changqing , Wang Deyi , Zhang Ruiyang , Liu Shubin
Published: January 2022

In this paper, a time projection chamber (TPC) system for α radiation detection with ultra-low background is presented, which is based on Micromegas, a type of micro-pattern gaseous detector. Based on multi-dimensional information acquired by the TPC, such as the features of particle energy deposition and 3D track, the system can achieve the purpose of α identification with ultra-low background. A prototype TPC with the volume of 15 × 15 × 6.5 cm3 was developed. It was filled with a gas mixture of 95% neon and 5% isobutene at about 1 bar, and no additional shielding or control of alpha-emitting materials was employed. A low-noise high-integration electronic system based on multi-channel waveform sampling techniques was adopted to read out the anode strip signals. A test with a 241Am α source (5.5 MeV), a 49-h background test, and several other tests with weak radioactive samples in the laboratory environment were conducted. A feature selection method was designed to maximize the suppression of background events while retaining the events of interest. Test results showed that within an assumed 5 × 5 cm2 effective area in the center region of the TPC window, the background count rate of this system was lower than 1.6 × 10−3 counts per minute at 95% confidence level, while retaining the acceptance rate of about 96% for 241Am α particles.
3D velocity map imaging of electrons with TPX3CAM
Authors: Cheng Chuan , Moğol Gönenç , Weinacht Thomas , Nomerotski Andrei , Trallero-Herrero Carlos
Published: January 2022

We demonstrate three-dimensional velocity map imaging of low energy electrons using a TPX3CAM, where the three-dimensional momentum information [px, py, pz] is encoded in position and timing [x, y, t] of hits on the camera sensor. We make use of the camera sensor for the [x, y] information and a constant fraction discriminator and fast time to digital converter in the camera for the time information. We illustrate the capabilities of our apparatus by presenting above threshold ionization measurements of xenon, which produces well defined structures in the momentum resolved photoelectron yield.
Cross-channel distribution and streamwise dispersion of micro-swimmers in a vertical channel flow: A study on the effects of shear, particle shape, and convective inertial torque
Authors: Wang Bohan , Jiang Weiquan , Chen Guoqian
Published: January 2022

In quiescent water, gyrotactic micro-swimmers swim upward on average. This anti-gravity swimming behavior is usually thought to be caused by micro-swimmers' bottom-heaviness. However, recent research has shown the importance of convective inertial torque in the orientational dynamics of settling elongated particles, and the torque can cooperate with self-propulsion to result in an effective gyrotactic mechanism. In this paper, we compare the cross-channel distribution and streamwise dispersion of micro-swimmers with and without convective inertial torque in a two-dimensional vertical channel flow, using a recently proposed generalized Taylor dispersion method. Meanwhile, we incorporate other effects such as shear-shape interaction and wall accumulation. Reflective boundary condition and Robin boundary condition are imposed to represent periodic boundaries and mimic motility-induced wall accumulation effect, respectively. For non-gyrotactic inertialess elongated micro-swimmers, a transition from high-shear trapping regime to low-shear trapping regime appears, consistent with results in previous studies. For micro-swimmers with an effective gyrotaxis intensity resulting from the convective inertial torque, their macroscopic transport properties are essentially the same as those of inertialess micro-swimmers with the same aspect ratio and an equal physical gyrotaxis intensity. The non-monotonic variations of effective drift velocity and dispersivity as functions of the flow rate are also characterized. Additionally, upstream swimming behavior, which is reflected by negative drift velocity, is found in weak flows for both gyrotactic micro-swimmers and non-gyrotactic micro-swimmers with motility-induced wall accumulation.
Detection and tuning of spin-orbit interactions on inclined-grown Bi2O2Se nanoplates
Authors: Gao Jie , Lu Fangchao , Liu Xiaolong , Deng Jiajun , Zhang Xiaoyue , Sun Zhenhao , Liu Xingchen , Shi Xiaojing , Wang Nan , Wu Yuting , Wang Wenjie , Ding Xunlei
Published: January 2022

Inclined semiconductor Bi2O2Se nanoplates of a high crystal quality were prepared via chemical vapor deposition, and a circular photogalvanic effect (CPGE) current was detected in them. The CPGE current in the Bi2O2Se nanoplate reached 100 nA/W, which is far beyond what has been found in other two-dimensional (2D) materials, e.g., Bi2Se3, WSe2, and Sb2Te3, as well as some 2D electron systems such as AlxGa1-xN/GaN heterostructures, indicating the large spin–orbit coupling (SOC) in inclined Bi2O2Se. To tune the strength of the SOC, an ionic liquid gate was applied to the Bi2O2Se nanoplate. The significant increase in the CPGE current that appeared with the application of the positive gate voltage indicates that the gate can further break spatial inversion symmetry, leading to enhanced SOC. Unlike the in-plane Bi2O2Se, the bottom surface of which has electrostatic interactions with the mica substrate and hence is naturally asymmetric with the top surface, the inclined-grown nanoplate has two Bi2O2Se-air interfaces. Therefore, the large CPGE current in the inclined Bi2O2Se shows that strong SOC is intrinsic to the Bi2O2Se lattice instead of the interfaces, and Bi2O2Se is a prospective material in the application of spintronic devices.
Localization of anisotropic exciton polariton condensates in perovskite microcavities
Authors: Li Honghao , Ai Qiang , Li Yao , Zhai Xiaokun , Liu Tong , Ren Yuan , Gao Tingge
Published: January 2022

Perovskite materials such as CsPbBr3 attract intensive attention due to excellent photonic properties. Especially, the exciton polariton condensate based on perovskite CsPbBr3 has been realized at room temperature. In this work, we observe the XY splitting of exciton polaritons localized in disorder induced potential traps in a CsPbBr3 microcavity due to the anisotropy of the perovskite and polariton condensation onto the horizontally and vertically linear polarized modes. In addition, the refractive index of the microcavity can be modified by filling liquid crystal molecules into the cavity layer, which can modify the XY splitting of localized polaritons. Our results pave the way to study the nontrivial band structure based on the XY splitting of the localized polariton condensate in microcavities.
Electrospray propulsion: Modeling of the beams of droplets and ions of highly conducting propellants
Authors: Gamero-Castaño Manuel , Galobardes-Esteban Marc
Published: January 2022

This article presents a model for the beams of charged droplets and ions typical of electrospray thrusters. The model is applied to a typical highly conducting propellant operating in the mixed droplet-ion emission regime but can be extended to simulate other emission regimes. A key feature of the model is the separation of the beam in two zones: a small inner region including the droplet emission area, where the equations of motion of all droplets are integrated simultaneously while retaining direct droplet-on-droplet Coulomb interactions and a much larger outer region where the beam is treated as a continuum. In addition to the geometry of the electrodes, inputs to the model include the distribution of diameters and charge-to-mass ratios of the droplets and their initial positions and velocities. Most of this information is determined from experiments. The analysis of the numerical solution confirms that lateral oscillations of the slender jet producing the droplets is an important factor in the expansion of electrospray beams, and that droplets in flight are the main sources of ion emission in these propellants. In addition to improving the knowledge of the physics of electrospray beams, the model is a significant tool for designing the extractor and accelerator electrodes of electrospray thrusters and for minimizing the deposition of beam particles on the surfaces of spacecrafts.
Onset of convective instability in an inclined porous medium
Authors: Luther Emmanuel E. , Dallaston Michael C. , Shariatipour Seyed M. , Holtzman Ran
Published: January 2022

The diffusion of a solute from a concentrated source into a horizontal, stationary, fluid-saturated porous medium can lead to a convective motion when a gravitationally unstable density stratification evolves. In an inclined porous medium, the convective flow becomes intricate as it originates from a combination of diffusion and lateral flow, which is dominant near the source of the solute. Here, we investigate the role of inclination on the onset of convective instability by linear stability analyses of Darcy's law and mass conservation for the flow and the concentration field. We find that the onset time increases with the angle of inclination (θ) until it reaches a cutoff angle beyond which the system remains stable. The cutoff angle increases with the Rayleigh number, Ra. The evolving wavenumber at the onset exhibits a lateral velocity that depends non-monotonically on θ and linearly on Ra. Instabilities are observed in gravitationally stable configurations (θ≥90°) solely due to the nonuniform base flow generating a velocity shear commonly associated with Kelvin–Helmholtz instability. These results quantify the role of medium tilt on convective instabilities, which is of great importance to geological CO2 sequestration.
Switchable out-of-plane shift current in ferroelectric two-dimensional material CuInP2S6
Authors: Zhang Yijin , Taniguchi Rei , Masubuchi Satoru , Moriya Rai , Watanabe Kenji , Taniguchi Takashi , Sasagawa Takao , Machida Tomoki
Published: January 2022

Polar materials are interesting platforms for fundamental research because they exhibit the spontaneous electric polarization (SEP) and the shift current photovoltaic effect, both originating from the inherent Berry connection. Owing to the electrical controllability, these phenomena are often studied in ferroelectric materials. Recently, the SEP and the shift current are enthusiastically studied in two-dimensional materials, but an electrical control has not been realized. In this study, we observed an out-of-plane shift current and demonstrated its electrical control at room temperature in a ferroelectric two-dimensional material CuInP2S6, by utilizing a multilayer graphene as a transparent electrode. The shift current origin was confirmed by an analysis of the excitation power dependence. Our results are an important step in the study of the Berry connection physics as well as put forward a device concept to utilize out-of-plane shift current photovoltaic effect for optoelectronic devices.
Scattering-type scanning near-field optical microscopy with Akiyama piezo-probes
Authors: Dapolito Michael , Chen Xinzhong , Li Chaoran , Tsuneto Makoto , Zhang Shuai , Du Xu , Liu Mengkun , Gozar Adrian
Published: January 2022

Recent developments of the scattering-type scanning near-field optical microscope at cryogenic temperatures (cryogenic s-SNOM or cryo-SNOM) have led to many breakthroughs in the studies of low energy excitations in quantum materials. However, the simultaneous demands on vibration isolation, low base temperature, precise nano-positioning, and optical access make the construction of a cryo-SNOM a daunting task. Adding to the overhead space required for a cryo-SNOM is the atomic force microscopy control, which predominantly utilizes a laser-based detection scheme for determining the cantilever tapping motion. In this work, we provide an alternative and straightforward route to performing s-SNOM using metal-coated Akiyama probes, where the cantilever tapping motion is detected through a piezoelectric signal. We show that the Akiyama-based cryo-SNOM attains high spatial resolution, good near-field contrast, and is able to perform imaging with a significantly more compact system compared to other cryo-SNOM implementations. Our results firmly establish the potential of s-SNOM based on self-sensing piezo-probes, which can easily accommodate far-infrared wavelengths and high magnetic fields in the future.
Chemisorbed vs physisorbed surface charge and its impact on electrokinetic transport: Carbon vs boron nitride surface
Authors: Mangaud Etienne , Bocquet Marie-Laure , Bocquet Lydéric , Rotenberg Benjamin
Published: January 2022

The possibility of controlling electrokinetic transport through carbon and hexagonal boron nitride (hBN) nanotubes has recently opened new avenues for nanofluidic approaches to face outstanding challenges such as energy production and conversion or water desalination. The pH-dependence of experimental transport coefficients points to the sorption of hydroxide ions as the microscopic origin of the surface charge and recent ab initio calculations suggest that these ions behave differently on carbon and hBN, with only physisorption on the former and both physisorption and chemisorption on the latter. Using classical non-equilibrium molecular dynamics simulations of interfaces between an aqueous electrolyte and three models of hBN and graphite surfaces, we demonstrate the major influence of the sorption mode of hydroxide ions on the interfacial transport properties. Physisorbed surface charge leads to a considerable enhancement of the surface conductivity as compared to its chemisorbed counterpart, while values of the ζ-potential are less affected. The analysis of the MD results for the surface conductivity and ζ-potential in the framework of Poisson–Boltzmann–Stokes theory, as is usually done to analyze experimental data, further confirms the importance of taking into account both the mobility of surface hydroxide ions and the decrease in the slip length with increasing titratable surface charge density.
Dynamics of droplet impact on a ring surface
Authors: Lin Chensen , Cao Damin , Zhao Dongxiao , Wei Ping , Chen Shuo , Liu Yang
Published: January 2022

We investigate the dynamics of droplet impacts on a ring-decorated solid surface, which is reported to reduce the integral of contact area over contact time by up to 80%. By using many-body dissipative particle dynamics (MDPD), a particle-based simulation method, we measure the temporal evolution of the shape and the impact force of two specific types of phenomena, overrun and ejection. The numerical model is first validated with experimental data on a plain surface from literature. Then, it is used to extract the impacting force of the ring and substrate separately, showing the ring does not provide the majority of vertical force to redirect the horizontal spreading. The impacting pressure in different concentric rings is also present as a function of time, showing pressure waves traveling from ring to center. The effect of the ring's height and radius on the impacting force is also discussed. To the best of our knowledge, this is the first MDPD study on droplets impacting on a solid surface with a validated force analysis.
On the three-dimensional wake flow behind a normal flat plate
Authors: Ong Muk Chen , Yin Guang
Published: January 2022

Two-dimensional (2D) and three-dimensional (3D) numerical simulations are carried out for uniform flow past a normal flat plate with two semicircular ends to investigate the three-dimensional effects of the wake flow behind the plate. The Reynolds numbers under investigation based on the inflow velocity and the width of the plate (H) are Re= 125, 200, 250, 500, and 1000. The instantaneous vortical structures show that the three-dimensionality characterized by streamwise vortical ribs becomes obvious at Re=200. Their spatial densities increase with the increasing Re. The time-averaged drag coefficient remains almost the same from Re=500 to 1000. The relative difference of the predicted drag coefficients between 2D and 3D simulations can be up to 77%. The amplitude of the lift force obtained using 2D simulations can be up to 30 times that obtained using 3D simulations. A drag force element decomposition analysis is conducted for the results obtained using 2D and 3D simulations. It is found that although the time-averaged wake flows obtained using the 2D and 3D simulations are different, the relative difference of their contributions to the time-averaged drag coefficient is only 10% while the difference comes mainly from the contribution of the Reynolds shear stress. The three-dimensionality of the wake flow is further investigated using quadrant and the Lumley triangle analysis of the Reynolds stress. The spanwise spatial scales of the streamwise vortices are quantified using Hilbert transform along the spanwise direction. The width of the streamwise vortices is approximately 0.5–1H in the near wake region. The dependence of the spatial scales on Re is discussed.
Two-step nucleation of the Earth’s inner core
Authors: Sun Yang , Zhang Feng , Mendelev Mikhail I. , Wentzcovitch Renata M. , Ho Kai-Ming
Published: January 2022

Significance

Understanding the formation of the Earth’s inner core is essential to understanding the geodynamo and Earth's history. However, recent attempts to explain the initial solidification of the inner core have been unsuccessful. The supercooling necessary to form hcp iron is unrealistically large and creates the “inner core nucleation paradox.” Our work demonstrates that molten iron can crystallize via a two-step nucleation process involving the intermediate bcc phase under core conditions. This mechanism significantly reduces the required undercooling necessary to nucleate solid iron. This work also suggests that bcc and hcp iron have similar free energies at pressures near the inner core center.
Angular correlations of causally-coherent primordial quantum perturbations
Authors: Hogan Craig , Meyer Stephan S
Published: January 2022

We consider the hypothesis that nonlocal, omnidirectional, causally-coherent quantum entanglement of inflationary horizons may account for some well-known measured anomalies of cosmic microwave background (CMB) anisotropy on large angular scales. It is shown that causal coherence can lead to less cosmic variance in the large-angle power spectrum C

ℓ
of primordial curvature perturbations on spherical horizons than predicted by the standard model of locality in effective field theory, and to new symmetries of the angular correlation function C(Θ). Causal considerations are used to construct an approximate analytic model for C(Θ) on angular scales larger than a few degrees. Allowing for uncertainties from the unmeasured intrinsic dipole and from Galactic foreground subtraction, causally-coherent constraints are shown to be consistent with measured CMB correlations on large angular scales. Reduced cosmic variance will enable powerful tests of the hypothesis with better foreground subtraction and higher fidelity measurements on large angular scales.
Failure of the split property in gravity and the information paradox
Authors: Raju Suvrat
Published: January 2022

In an ordinary quantum field theory, the ‘split property’ implies that the state of the system can be specified independently on a bounded subregion of a Cauchy slice and its complement. This property does not hold for theories of gravity, where observables near the boundary of the Cauchy slice uniquely fix the state on the entire slice. The original formulation of the information paradox explicitly assumed the split property and we follow this assumption to isolate the precise error in Hawking’s argument. A similar assumption also underpins the monogamy paradox of Mathur and AMPS. Finally, the same assumption is used to support the common idea that the entanglement entropy of the region outside a black hole should follow a Page curve. It is for this reason that computations of the Page curve have been performed only in nonstandard theories of gravity, which include a nongravitational bath and massive gravitons. The fine-grained entropy at

I

+

does not obey a Page curve for an evaporating black hole in standard theories of gravity but we discuss possibilities for coarse graining that might lead to a Page curve in such cases.
Overview of photonic devices based on functional material-integrated photonic crystal fibers
Authors: Wang Xinyu , Li Shuguang , Cheng Tonglei , Li Jianshe
Published: January 2022

Photonic crystal fibers (PCFs) have brought tremendous advancements due to their predominant feature of a peculiar air-hole arrangement in the 2D direction. Functional materials like metals, magnetic fluids, nematic liquid crystals, graphene and so on, are being extensively adopted for integration with PCFs to obtain extraordinary transmission properties. This review takes the development stages of photonic devices based on functional material-infiltrated PCFs into consideration, covering the overview of common materials and their photoelectric characteristics, state-of-art infiltrating/coating techniques, and the corresponding applications involving polarization filtering and splitting devices in optical communication and sensing elements related to multiple-parameter measurement. The cladding airhole of PCFs provides a natural optofluidic channel for materials to be introduced, light–matter interaction to beenhanced, and transmission properties to be extended, in this case, a lab on a fiber are able to be implemented. This paves the way for the development of photonic devices in the aspects of compact, multi-functional integration as well as electromagnetic resistance. When the PCFs are integrated with the phemomenon of surface plasmon resonance, the property of tunable refractive indices, and the flexible geometry structures, it comes up to some representative researches on polarization filters, multiplexer-demultiplexers, splitters, couplers and sensors. It makes a candidate for widespread fields of telecommunication, signal-capacity, and high-performance sensing.
Tunable dual plasmon-induced transparency and slow-light analysis based on monolayer patterned graphene metamaterial
Authors: Yao Pengju , Zeng Biao , Gao Enduo , Zhang Hao , Liu Chao , Li Min , Li Hongjian
Published: January 2022

We propose a novel terahertz metamaterial structure based on patterned monolayer graphene. This structure produces an evident dual plasmon-induced transparency (PIT) phenomenon due to destructive interference between bright and dark modes. Since the Fermi level of graphene can be adjusted by an external bias voltage, the PIT phenomenon can be tuned by adjusting the voltage. Then the coupled-mode theory (CMT) is introduced to explore the internal mechanism of the PIT. After that, we investigate the variation of absorption rate at different graphene carrier mobilities, and it shows that the absorption rate of this structure can reach 50%, which is a guideline for the realization of graphene terahertz absorption devices. In addition, through the study of the slow-light performance for this structure, it is found that its group index is as high as 928, which provides a specific theoretical basis for the study of graphene slow-light devices.
Y2O3-based memristive crossbar array for synaptic learning
Authors: Gautam Mohit Kumar , Kumar Sanjay , Mukherjee Shaibal
Published: January 2022

Here, we report the fabrication of an Y2O3-based memristive crossbar array along with an analytical model to evaluate the performance of the memristive array system to understand the forgetting and retention behavior in the neuromorphic computation. The developed analytical model is able to simulate the highly dense memristive crossbar array-based neural network of biological synapses. These biological synapses control the communication efficiency between neurons and can implement the learning capability of the neurons. During electrical stimulation of the memristive devices, the memory transition is exhibited along with the number of applied voltage pulses, which is analogous to the real human brain functionality. Further, to obtain the forgetting and retention behavior of the memristive devices, a modified window function equation is proposed by incorporating two novel internal state variables in the form of forgetting rate and retention. The obtained results confirm that the effect of variation in electrical stimuli on forgetting and retention is similar to that of the biological brain. Therefore, the developed analytical memristive model can further be utilized in the memristive system to develop real-world applications in neuromorphic domains.
Freestanding Fe3O4/Ti3C2T
x
MXene/polyurethane composite film with efficient electromagnetic shielding and ultra-stretchable performance
Authors: Hu Yongqin , Hou Chen , Shi Yuxia , Wu Jiamei , Yang Da , Huang Zhuili , Wang Yan , Liu Yufei
Published: January 2022

Electromagnetic pollution seriously affects the human reproductive system, cardiovascular system, people’s visual system, and so on. A novel versatile stretchable and biocompatible electromagnetic interference (EMI) shielding film has been developed, which could effectively attenuate electromagnetic radiation. The EMI shielding film was fabricated with a convenient solution casting and steam annealing with 2D MXene, iron oxide nanoparticles, and soluble polyurethane. The EMI shielding effectiveness is about 30.63 dB at 8.2 GHz, based on its discretized interfacial scattering and high energy conversion efficiency. Meanwhile, the excellent tensile elongation is 30.5%, because of the sliding migration and gradient structure of the nanomaterials doped in a polymer matrix. In addition, the film also demonstrated wonderful biocompatibility and did not cause erythema and discomfort even after being attached to the arm skin over 12 h, which shows the great potential for attenuation of electromagnetic irradiation and protection of human health.
Reversible down-regulation and up-regulation of catalytic activity of poly(N-isopropylacrylamide)-anchored gold nanoparticles
Authors: Han Yufen , Li Jiaqian , Zhang Xiaojin , Xia Fan , Dai Yu
Published: January 2022

Regulating catalytic activity plays an important role in further optimizing and developing multifunctional catalysts with high selectivity and high activity. Reversible dual regulation of catalytic activity has always been a challenging task. Here, we prepared poly(N-isopropylacrylamide)-anchored gold nanoparticles (AuNP@CDs-Azo-PNIPAM) through host-guest interaction of cyclodextrin capped gold nanoparticles (AuNP@CDs) and azobenzene-terminated poly(N-isopropylacrylamide) (Azo-PNIPAM). Azo-PNIPAM as thermal and light responsive ligand allows reversible dual regulation of catalytic activity. When the temperature is higher than the lowest critical solution temperature, the PNIPAM chain shrinks rapidly, increasing the steric hindrance around AuNPs and reducing the catalytic activity. Under ultraviolet light irradiation, cis-azobenzene disassembles from cyclodextrin and the number of surface active sites of AuNPs increases, which improves the catalytic activity. The reaction rate of UV irradiation is almost 1.3 times that of visible light irradiation. This work provides a simple and effective strategy for the construction of reversible catalysts.
Dealing with artefacts in JET iterative bolometric tomography using masks
Authors: Peluso Emmanuele , Gelfusa Michela , Craciunescu Teddy , Martellucci Luca , Gaudio Pasqualino , Carvalho Pedro , Murari Andrea
Published: January 2022

Bolometric tomography is a widely applied technique to infer important indirect quantities in magnetically confined plasmas, such as the total radiated power. However, being an inverse and ill-posed problem, the tomographic algorithms have to be carefully steered to converge on the most appropriate solutions, and often specialists have to balance the quality of the obtained reconstructions between the core and the edge of the plasma. Given the topology of the emission and the layout of the diagnostics in practically all devices, the tomographic inversions of bolometry are often affected by artefacts, which can influence derived quantities and specific studies based on the reproduced tomograms, such as power balance studies and the benchmarking of gyrokinetic simulations. This article deals with the introduction of a simple, but very efficient methodology. It is based on constraining the solution of the tomographic inversions by using a specific estimate of the initial solution, built with the data from specific combinations of detectors (called ‘masks’). It has been tested with phantom and with real data, using the Maximum Likelihood approach at JET. Results show how the obtained tomograms improve sensibly both in the core and at the edge of the device, when compared with those obtained without the use of masks as the initial guess. The correction for the main artefacts can have a significant impact on the interpretation of both the core (electron transport, alpha heating) and the edge physics (detachment, SOL). The method is completely general and can be applied by any iterative algorithm starting from an initial guess for the emission profile to be reconstructed.
Biochemical indicators of woody plants in the diagnosis of air condition
Authors: Anishchenko L N , Borzdyko E V , Dolganova M V , Moskalenko I V , Avramenko M V
Published: January 2022

It is found that anthropogenic pollution has a significant effect on the change in the content of total nitrogen, glutathione and vitamin E, which increases the resistance of woody plants to stress. A series of woody plants with regard to their sensitivity to aerosol pollution has been compiled: according to the degree of decrease in total nitrogen – Picea abies > Thuja occidentalis > Syringa vulgaris > Acer platanoides > Tilia cordata > Sorbus aucuparia; the degree of decrease in glutathione content – Picea abies > Thuja occidentalis > Syringa vulgaris > Acer platanoides > Tilia cordata > Sorbus aucuparia; the degree of decrease in the content of vitamin E – Picea abies > Thuja occidentalis > Sorbus aucuparia > Tilia cordata > Syringa vulgaris > Acer platanoides. A positive correlation was revealed between the biochemical parameters of woody plants and the monitoring complex indices proposed by the Russian meteorological service. A close direct regression dependence of the air pollution index and the average stability coefficient for the content of total nitrogen, vitamin E and glutathione in the biomass of model woody plants was revealed: with an increase in the degree of air pollution, the average stability coefficient for certain biochemical indicators increases.
Synanthropic rodent fauna of Eastern Transbaikalia in the early 21st century
Authors: Bazhenov Yu A
Published: January 2022

The article provides information on the synanthropic rodent fauna of Eastern Transbaikalia. In 2017–2020 the city of Chita, the town of Baley and small settlements of Zabaykalsky krai were surveyed. True synanthropes: the house mouse and the brown rat are most abundant in residential landscapes. Natural populations of the house mouse are typical for coastal biotopes of the steppe zone, and the brown rat is typical for forest-steppe zone of Zabaykalsky krai. In Chita (administrative centre of Zabaykalsky krai) the share of the brown rat in rodent communities has considerably increased in recent decades. There is an extension of the brown rat’s habitat in the area of Baikal-Amur Mainline. Optional synanthropes: striped field mouse, striped dwarf hamster, Maximowicz’s vole, and narrow-headed vole are less important in residential landscapes of the region. In the beginning of the 21st century the field mouse is extending its habitat to the disjunct zone to the west of Transbaikalia: it is now common in the residential area of the town of Baley. Penetration of another optional synanthropic species recorded in the neighbouring Siberian regions – the East European vole – has not been detected.
Ice 0: the experimental proof of its existence – the result of combining approaches used in radiophysics, geology and geography
Authors: Bordonskiy G S
Published: January 2022

The experience of combining the efforts of researchers working at the interface of radiophysics, geology and geography is discussed. The effectiveness of such collaboration of researchers is shown by the example of the experimental proof of the existemce of a new crystalline modiciation of ice, ice 0. This kind of ice is formed at the temperature below –23 °C out of supercooled water, and, together with ice Ih and ice Ic, may be formed at the temperatures and pressures corresponding to the surface layers of the Earth’s atmosphere. For this reason, this study is of great interest for understanding the natural processes taking place in the geospheres (atmosphere, cryosphere, biosphere, and hydrosphere).
The effectiveness of the use of Sinorhizobium meliloti in the cultivation of variable alfalfa (Medicago varia Mart.)
Authors: Ivanova E P , Skalozub O M
Published: January 2022

As a result of three-year studies, we have established a growth in the yield and feed advantages of variable alfalfa in the variants with inoculation of seeds with virulent active strains of rhizobia. The total yield augmentation of green mass in the experimental variants over the three years of alfalfa life were 6.8–13.7 % compared to the control ones. The positive effect of inoculation with virulent active rhizobia strains on the total collection of dry matter was expressed in its increase in experimental conditions by 12.6–21.7 %. The highest yield of green mass, as well as dry matter was obtained in the variant with the inoculation of alfalfa seeds with the main production strain 425. The researched factor has a positive effect on the collection of feed units, digestible protein and feed protein units from 1 ha. The collection of feed units per hectare in the experimental versions increases by 1.1–1.3 times, the collection of digestible protein – by 1.2–1.4 times. The maximum substance of feed units and digestible protein per hectare was observed in the version with seed inoculation with strain 425a. The provision of a feed unit with digestible protein increases by 10.44–18.18 g or by 6.1–10.6 %.
The ecological characteristics of small rivers in the Shilka river basin by zoobenthos organisms
Authors: Kazikina S M
Published: January 2022

Zoobenthos organisms are directly related to the biogeochemical processes occurring at the bottom and in the water column of the channel. The paper presents the results of studies of the quantitative characteristics of the zoobenthos and the water quality of small rivers in the river basin of Shilka in the area of gold mining enterprises.
Analysis of recreational needs of visitors to the Arey Nature Park
Authors: Pomazkova N V , Ts Darmaeva O
Published: January 2022

The article presents the results of a sociological survey of visitors to the Arey Nature Park. Based on the questionnaire conducted in July 2020, the paper demonstrates an analysis of recreational needs and a sociological portrait of a visitor to the Arey Nature Park. The article analyses suggestions of vacationers and contains recommendations based on the identified needs and problems mentioned by the visitors in the organization of operation of the protected area. Almost all park visitors note a strong appeal to the natural scenery of the territory. The sanitary condition of the territory and the limited range of services available are highlighted as significant shortcomings in the operation of the park administration.
Water as a thermodynamic parameter of biosphere evolution
Authors: Ptitsyn A B , Matyugina E B
Published: January 2022

Water has a profound influence on the evolution of the biosphere and can be regarded as a thermodynamic parameter. The priorities and objectives in this research include determining the hydrological features of rivers and lakes in the region as indicators of the thermodynamic activity of water in the evolutionary processes; hydrology and ecology of the cryptobiosphere; the effects of water on the evolutionary adaptations and strategies in living organisms in biogeochemical systems of different origins; and the hydrology of possible alternative stable states of biogeochemical systems.
Technogenesis and Ecological State of Natural Waters in Eastern Transbaikalia
Authors: Ts Tsybekmitova G
Published: January 2022

The research on the state of water ecosystems is significant in terms of future biological impacts of natural and anthropogenic effects. The key branches of natural resources management in Eastern Transbaikalia (agriculture, hydraulic power industry) are based on using water resources. The findings show that technogenesis affects surface waters of the region. Alluvial gold mining represents a significant part of mining industry. Gold mining in river channels results in run-of-stream diversion and interferes with the ecosystem of watercourses. A newly formed structure of a water ecosystem is not favourable for self-purification capacity of rivers. This leads to pollutants accumulation in water objects and deteriorates ecological state of watercourses. Natural components in the technoecosystem of hydropower objects in Eastern Transbaikalia are Lake Kenon and the Kharanor Reservoir. Although the catchment area is polluted by TPP-1, the ecosystem of the lake is still capable of self-purification due to biodiversity of hydrobionts. Under the dry climate in recent years, the Kharanor Reservoir ecosystem turned as rather unstable due to constant refilling from the Onon River. However, generally, pigment indices show physiological activity of primary producers of organic matter.
Plant communities with Ulmus japonica (Rehd.) Sarg. in Eastern Transbaikalia
Authors: Vikulina N A , Kayukova S N , Ishina L A
Published: January 2022

The article presents the data of long-term studies of communities with U. japonica in Eastern Transbaikalia, in particular, the results of anatomical studies, floristic, ecological and biological, biomorphological and arealogical analysis of the flora of elms.
Bituminous substances in soils of Baikal Rift zone
Authors: Vishnyakova O V , Ubugunova V I , Ubugunov V L , Ubugunov L L
Published: January 2022

Parameters of hydrocarbon complex of the soils of lacustrine-alluvial plain and sandy uplands of the Baikal rift zone within the Barguzin Depression have been studied. Data were obtained on organic (non-carbonate) carbon, chloroform and hexane bitumoids, as well as on individual polycyclic aromatic hydrocarbons. The content, composition and properties of bitumoids vary depending on the intensity of endogenous activity. In soils located in the zone of active unload of hydrothermal waters and hydrocarbon fluids, atypical accumulation of organic carbon was noted; the concentrations of bitumoids do not correlate with its content. High values of the bitumoid coefficient, significant level of polycyclic aromatic compounds and their diversity, in combination with salts accumulation, indicate an additional influx of hydrocarbons and instability of the soil hydrocarbon system. The level of the indicators shifts towards background values in the soils of sandy hills with a complex combination of exogenous and endogenous factors of soil forming. Studied parameters of the soil hydrocarbon system in aggregate can serve as markers of the intensity of endogenous processes.
Quantitative characteristics of zooplankton in the rivers of the Upper Amur Basin, exposed to the effects of placer gold mining
Authors: Zykova E H
Published: January 2022

Research conducted in June and September 2020 showed that the species composition of rotifers and lower crustaceans in 17 water courses of the Upper Amur Basin, exposed to the effects of placer gold mining, included 43 species. Most of the water courses were researched for the first time. Based on the environmental and geographic assessment, the prevalent species were widespread and eurytopic. Most parts of the rivers were characterised by low quantitative characteristics (0.01–3.77 × 103 ind. m-3 and 0.06–54.64 mg m-3), which was explained by the hygrological conditions and long-term effects of mining in the river beds. A better productivity (up to 39 × 103 ind. m-3 and 228 mg m-3) was registered in the areas of former excavations in the river beds, with slower water exchange and better conditions for the development of zooplankton.
Efficiency of using peroxide-carbonate compounds in reagent complexes for leaching gold hard to recover from placer
Authors: Sekisov A G , Konareva T G , Yu Lavrov A , Yu Burov V , Emirziadi E S
Published: January 2022

The article deals with the data of theoretical and experimental studies of the processes of activation gold leaching using reactive peroxide carbonate compounds, obtained by electrophotochemical treatment of solutions of initial reagents of the corresponding composition, in the composition of reagent complexes. The obtained results of the experiments on the interaction of various carbonate and peroxide-carbonate compounds with sodium cyanide in the process of mixing activated and non-activated solutions with aqueous cyanide solutions in different order definitely prove that supramolecular percarbonate-cyanide compounds are being formed in them. It has been established that these activated solutions, prepared on the basis of the initial hydrocarbonate ones, contain metastable compounds that provide a higher rate of gold extraction from crude minerals than standard aqueous cyanic solutions of the same initial concentration.
Antimony, arsenic and bismuth in sediments of the Ukureyskaya formation of the Olovskaya depression in Transbaikalia, containing fossil remains of the dinosaurs of a new genus and species Kulindadromeus zabaikalicus
Authors: Vasilenko E A
Published: January 2022

The concentrations of antimony, arsenic, and bismuth in sediments of the Ukureyskaya formation of the Olovskaya Depression in Transbaikalia are considered. It was determined that their maximum concentrations are confined to the sediments around the village of Novoberezovskoye and Kulinda locality, which contains fossils of the dinosaurs Kulindadromeus zabaikalicus.
Mineral waters and sediments of the ferruginous spring Ulan-Bulak Urulyunguevsky (South-Eastern Transbaikalia, Russia)
Authors: Zamana L V
Published: January 2022

The data on the chemical composition and content of balneological components (Fe, H2SiO3, CO2, S2-) for three water samples from the Ulan-Bulak acidic ferruginous spring are presented. For the first time, carbonic water was released in the composition of the spring waters, the origin of which is explained by the ingress of hydrocarbonate water into an acidic medium, followed by dissociation according to the HCO3
- + H+ → H2CO3 → H2O + CO2 scheme. An acidic environment is formed as a result of oxidation of sulfide mineralization, presumably gold-bearing. From secondary minerals at the spring, modern sulfate minerals (gypsum, jarosite), hydromica (illite) were found, ocher sediments are widely developed. Given the uncertain nature of the formation of the spring waters, it is considered worthy of special studies, including an inspection of the presence of sulfide mineralization.
Cloud computing security requirements: A Review
Authors: Tsochev G R , Trifonov R I
Published: January 2022

Cloud computing is a new technology that is undergoing tremendous development today. People who use it are not able to separate the reasonable from the unreasonable arguments that come with the security requirements in the cloud. The claim that cloud computing is hereditarily insecure is as absurd as the claim that cloud computing does not create new security problems. Cloud computing is a way to dynamically increase resources without the need for in-depth knowledge of a brand new infrastructure, without training new workers or designing new software solutions. The article aims to analyse the different cloud security issues and models of cloud architectures. Some of the main problems with security in virtualization, concerns about storing data in the cloud and the assessment of risk tolerance in cloud computing are presented. Legal and regulatory issues for the protection of personal data are addressed.
Statistical models expressing relations between soil moisture, aggregate speed, and tillage depth at plowing and cultivation
Authors: Veleva P M , Hristova G M
Published: January 2022

The study is based on a one-year field experiment (2019) in the land of the Chirpan region located in central Bulgaria. The agrotechnical operations of plowing and cultivation, applied in technology for the production of sunflower, are studied. Four models (Linear, Exponential, Logarithmic, and Quadratic) were compared at p < 0.05, defining the relation between soil moisture, aggregate speed, and the uniformity of the soil index Tillage depth during plowing and cultivation. It was found that in plowing at a speed of 4 km/h the Quadratic model described the relation between soil moisture and tillage depth with the highest coefficient of determination (R2 = 0.682). Relating to plowing at a speed of 4.5 km/h the most suitable is the Exponential model (R2 = 0.729), i.e. about 68.2% and 72.9% of the variations in tillage depth are due to the influence of the moisture of the soil. The coefficients of determination, calculated when cultivating at speeds of 8 km/h (R2 = 0.526) and 9 km/h (R2 = 0.557), show that the Quadratic model most strongly (52.6% and 55.7%) determines the relation between soil moisture and tillage depth. The developed models could be used to optimize the control systems of agricultural machinery.