bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct bandgap dependence of bismuth films on their thickness
Authors: Nevinskas I. , Stanionytė S. , Devenson J. , Krotkus A.
Published: August 2022

Thin bismuth films of various thicknesses between 5 and 32 nm grown by molecular beam epitaxy on Si (111) substrates were investigated. The samples were characterized by the x-ray diffraction method, which allowed us to identify two types of Bi crystallographic structures—α and β bismuth. Terahertz radiation pulses emitted from the samples after their illumination by femtosecond optical pulses with different wavelengths were characterized. The main THz emission features were similar for both types of Bi layers. Due to 2D confinement, the electron energy band structure depends on the thickness. With the terahertz excitation spectroscopy method, direct bandgaps were determined to be in the range from 0.25 to 0.5 eV—much greater than the indirect bandgaps of the layers. A simple model was used to describe the nature of THz emission from these films, which is the cause of uncompensated lateral photocurrents occurring because of the diffusive electron scattering at the Bi/Si interface.
Sidewall effect on turbulent band in subcritical transition of high-aspect-ratio duct flow
Authors: Kohyama Kazuki , Sano Masaki , Tsukahara Takahiro
Published: August 2022

We numerically studied high-aspect-ratio channel flows with spanwise sidewalls, that is, wide duct flows, in its subcritical turbulent transitional regime. The infinite channel flow is known to form large-scale intermittency of turbulent–laminar coexistence and undergo two-stage transition (or crossover transition) process: a second-order phase transition with a critical Reynolds number Rec≈1000 and a deviation from it to maintain turbulence down to the global critical value Reg≈700. However, a real channel must have spatial finiteness, and its effect on transition phenomena is nontrivial. With the objective of understanding the turbulence maintenance limitations in the real channel flow, we investigated the effect of spanwise finiteness on the localized turbulence and its criticality, using direct numerical simulation. In our widest duct with an aspect ratio of 1:96 in the flow cross section, turbulent bands colliding with sidewalls above Re = 1069 often stochastically reflected or reversely traveled, keeping two-dimensional intermittencies with oblique bands, similar to the channel flow, whereas, in a narrower duct of 1:24, the critical value was higher as 1151 in the steeper transition profile, forming a quasi-one-dimensional intermittency dominantly. The transition in the high-aspect-ratio duct flow was converged to Reg≈1000 as the sidewall distance was increased. The critical phenomenon differs significantly from the channel flow for all duct flows, even for high aspect ratios. Due to spatial finiteness, the duct flows become fully laminar within a finite time for Re≲1000, unlike the channel flow. Possible causes of the difference in Reg between the two systems with fixed pressure gradient and fixed flow rate are discussed.
Coarse-grained description of monounsaturated peroxidized phospholipid bilayers
Authors: Zhang Yangyang , Liu Donghui , Zhang Yiyang , Guo Yachong , Li Wenfei , Thalmann Fabrice
Published: August 2022

Lipid peroxides result from a reaction between cis-unsaturated lipid chains and singlet oxygen molecules leading to the addition of a peroxide OOH side group next to the acyl-chain double bond. It is now established that HP-POPC (hydroperoxidized POPC) molecules form stable, thin, and laterally expanded bilayers. The difference in the structural organization arises from the hydrophilic character of the OOH side group that has a strong affinity with the water interface region, leading to significant reorganization of the bilayer. In this article, we describe a coarse-grained (CG) model of POPC and DOPC lipid peroxides within the framework of the Martini CG force-field (v2.2), derived from experimental data. We then discuss extensively the predicted structure and the influence of hydration and show how shifting the position of the unsaturated bonds along the chain changes the structure. Finally, we provide electron and neutron scattering length density profiles of the simulated bilayers.
Ultra-broadband frequency up-converter based on AlGaAs\GaAs heterojunction detector
Authors: Li X. H. , Huang S. H. , Bai H. Z. , Bai P. , Lian X. R. , Song W. J. , Shen W. Z. , Xu G. Y. , Zhang Y. H.
Published: August 2022

The development of high performance is essential for the realization of ultra-broadband imaging technology, which can be widely used in astronomy, medical health, defense and security, and many other applications. In this work, we demonstrate an ultra-broadband upconversion device based on a heterojunction interfacial work function internal photoemission (HEIWIP) detector and an AlGaAs/GaAs/In0.04Ga0.96 As quantum well LED. The up-converter exhibits an ultra-broad response covering from the terahertz to mid-infrared region (3–165 THz) due to free carrier absorption and inter-valence-band absorption in p-type based photodetectors. The peak responsivity in the terahertz and mid-infrared region is measured to be 7.2 A/W at 9.2 THz and 3.5 A/W at 28.8 THz, respectively, which is improved by an order of magnitude compared to the previous homojunction interfacial work function internal photoemission-based up-converter (0.5 A/W) in the THz region. The up-converter also demonstrates an improved upconversion efficiency of 1.5%. The noise equivalent power (NEP) of the imaging system consisting of the HEIWIP-LED up-converter and Si CCD is studied. The optimized NEP can achieve ∼10 pW/Hz1/2 in both terahertz and mid-infrared regions. The HEIWIP-LED up-converter exhibits excellent properties of high responsivity, ultra-broad response, and low noise, making it a great prospect for future applications in the field of ultra-broadband imaging.
Ultra-efficiency broadband terahertz polarization converter based on a cross-shaped metamaterial
Authors: Liu Wenjia , Zhang Yonggang , Liang Lanju , Yao Haiyun , Yan Xin , Qiu Fu , Huang Chengcheng , Li Weili , Tan Yihui , Li Weiran , Huang Yuxuan , Wu Jingbo , Zhang Caihong , Jin Biaobing
Published: August 2022

In this study, we describe the design, fabrication, and characterization of a cross-shaped structure reflective broadband THz polarization converter. The operating bandwidth of the proposed polarization converter was in the range of 0.8–1.6 THz. The polarization conversion rate (PCR) exceeded 85% in the frequency range of 1.07–1.35 THz and was as high as 91% at 1.35 THz. The cross PCR value exceeded 85% in the frequency range of 1.05–1.35 THz and reached a maximum value of 91%. The performance characteristics (bandwidth and PCR) of the proposed polarization converter were compared with those of similar previously reported devices, and the results indicated that the proposed polarization converter exhibits better performance. The proposed THz polarization converter is suitable for a wide range of applications in communication and polarization manipulation devices.
Precise interface engineering using a post-oxidized ultrathin MgAl layer for the voltage-controlled magnetic anisotropy effect
Authors: Nozaki Takayuki , Nozaki Tomohiro , Onoda Hiroshige , Nakayama Hiroyasu , Ichinose Tomohiro , Yamamoto Tatsuya , Konoto Makoto , Yuasa Shinji
Published: August 2022

The voltage-controlled magnetic anisotropy (VCMA) effect has been proposed as an energy efficient approach for controlling the direction of magnetization. To demonstrate the scalability of a voltage-controlled magnetoresistive random access memory, we need to optimize the perpendicular magnetic anisotropy (PMA), tunnel magnetoresistance (TMR), and VCMA properties. Here, we performed a systematic investigation of the effects of inserting a post-oxidized MgAl layer on PMA, TMR, and VCMA in epitaxial magnetic tunnel junctions (MTJs). PMA and TMR have substantial dependences on the thickness of the MgAl layer, and their maximum values occurred when the MgAl layer was 0.20 nm thick, resulting in threefold and twofold increases in the PMA energy and TMR ratio, respectively, compared with the case without a MgAl layer. On the other hand, the VCMA coefficient increased as the MgAl layer thickness decreased and had a maximum value of −350 fJ/Vm when the MgAl layer was 0.16 nm thick, suggesting that the weakly oxidized interface provides a larger VCMA effect. Interface engineering using a post-oxidized ultrathin MgAl layer provides us with a valuable technique for precisely controlling the PMA, TMR, and VCMA properties of voltage-controlled MTJs.
Self-formation of InAs/InGaAsSb type-II superlattice structures on InP substrates by MBE and their application to mid-infrared LEDs
Authors: Uno Kou , Iijima Naoto , Miyashita Naoya , Yamaguchi Koichi
Published: August 2022

InAs/InGaAsSb type-II superlattice structures (SLSs) were spontaneously formed by the molecular beam epitaxy of InAs/GaAs0.86Sb0.14 SLSs on InP substrates. The strain due to lattice mismatch between InAs and GaAs0.86Sb0.14 induced two exchange reactions of In–Ga and As–Sb at both InAs/GaAs0.86Sb0.14 heterointerfaces, resulting in the strain relaxation and the self-formation of InAs/InGaAsSb type-II SLS. By energy dispersive x-ray spectroscopy analysis, the mixed crystal composition of the InGaAsSb layer was determined to be approximately In0.8Ga0.2As0.9Sb0.1. Electroluminescence spectra of LEDs, including the self-formed InAs/In0.8Ga0.2As0.9Sb0.1 2.5-periodic SLS, showed double peaks of 2.6 and 3.2 µm at 15 K. The luminescence spectrum was based on two transition mechanisms of type-I transition in InAs and type-II transition between InAs and InGaAsSb. The experimental results of luminescence spectra were supported by theoretical calculations. The 3.3 µm emission was maintained above 220 K.
Magnetic imaging of superconducting qubit devices with scanning SQUID-on-tip
Authors: Marchiori E. , Ceccarelli L. , Rossi N. , Romagnoli G. , Herrmann J. , Besse J.-C. , Krinner S. , Wallraff A. , Poggio M.
Published: August 2022

We use a scanning superconducting quantum interference device (SQUID) to image the magnetic flux produced by a superconducting device designed for quantum computing. The nanometer-scale SQUID-on-tip probe reveals the flow of superconducting current through the circuit as well as the locations of trapped magnetic flux. In particular, maps of current flowing out of a flux-control line in the vicinity of a qubit show how these elements are coupled, providing insight on how to optimize qubit control.
Targeting acetyl-CoA metabolism attenuates the formation of fear memories through reduced activity-dependent histone acetylation
Authors: Alexander Desi C. , Corman Tanya , Mendoza Mariel , Glass Andrew , Belity Tal , Wu Ranran , Campbell Rianne R. , Han Joseph , Keiser Ashley A. , Winkler Jeffrey , Wood Marcelo A. , Kim Thomas , Garcia Benjamin A. , Cohen Hagit , Mews Philipp , Egervari Gabor , Berger Shelley L.
Published: August 2022

Histone acetylation is a key component in the consolidation of long-term fear memories. Histone acetylation is fueled by acetyl-coenzyme A (acetyl-CoA), and recently, nuclear-localized metabolic enzymes that produce this metabolite have emerged as direct and local regulators of chromatin. In particular, acetyl-CoA synthetase 2 (ACSS2) mediates histone acetylation in the mouse hippocampus. However, whether ACSS2 regulates long-term fear memory remains to be determined. Here, we show that Acss2 knockout is well tolerated in mice, yet the Acss2-null mouse exhibits reduced acquisition of long-term fear memory. Loss of Acss2 leads to reductions in both histone acetylation and expression of critical learning and memory-related genes in the dorsal hippocampus, specifically following fear conditioning. Furthermore, systemic administration of blood–brain barrier–permeable Acss2 inhibitors during the consolidation window reduces fear-memory formation in mice and rats and reduces anxiety in a predator-scent stress paradigm. Our findings suggest that nuclear acetyl-CoA metabolism via ACSS2 plays a critical, previously unappreciated, role in the formation of fear memories.
The Role of Spin-Flip Collisions in a Dark-Exciton Condensate
Authors: Misra Subhradeep , Stern Michael , Umansky Vladimir , Bar-Joseph Israel
Published: August 2022

We show that a Bose–Einstein condensate consisting of dark excitons forms in GaAs coupled quantum wells at low temperatures. We find that the condensate extends over hundreds of micrometers, well beyond the optical excitation region, and is limited only by the boundaries of the mesa. We show that the condensate density is determined by spin-flipping collisions among the excitons, which convert dark excitons into bright ones. The suppression of this process at low temperature yields a density buildup, manifested as a temperature-dependent blueshift of the exciton emission line. Measurements under an in-plane magnetic field allow us to preferentially modify the bright exciton density and determine their role in the system dynamics. We find that their interaction with the condensate leads to its depletion. We present a simple rate-equations model, which well reproduces the observed temperature, power, and magnetic-field dependence of the exciton density.
Spatially averaged ion temperature model for low-temperature plasma sources
Authors: Kwon Deuk-Chul , Yook Yeong-Geun , Chung Sang-Young , Chang Won-Seok , Yu Dong-Hun , Im Yeon-Ho
Published: August 2022

Although the ion temperature can considerably affect bulk plasma parameters and ion angle distribution functions arriving at the substrate, limited experiments have been conducted on this phenomenon because ion temperature measurement is difficult. Furthermore, only a few simulations have been performed under specific conditions. Therefore, in this study, a novel method was developed to calculate the ion temperature using a global model. The spatially averaged ion temperature equation was derived by integrating the ion temperature over space. Continuity and electron temperature equations were used in a self-consistent manner to solve the equation. We investigated radio-frequency inductively coupled Ar, N2, and Cl2 discharges in the pressure range of 5–20 mTorr and power range of 200–1000 W. The obtained results were highly consistent with experimental and two-dimensional simulation results.
Numerical simulation of effectively driving the trajectory of magnetic particles in a Newtonian fluid using a uniform magnetic field
Authors: Xu Zhiqiang , Chen Feng , Bo Xinqian , Tang Zhifa , Jiang Shengqiang
Published: August 2022

Herein, the interaction and relative motion of two circular magnetic particles in a static flow and planar Poiseuille flow is investigated via numerical simulation. A two-dimensional numerical model is constructed based on Maxwell’s finite element method, fully considering the interactions between particles and particles, particles and magnetic fields, and particles and flow fields. First, the motion state and action mechanism of the magnetic particles in contact state in the static fluid are analyzed under a vertical magnetic field; then, the simulation results are verified via experiments. Based on the motion state of the magnetic particles in the planar Poiseuille flow, the feasibility of effectively controlling the trajectory of magnetic particles in the planar Poiseuille flow using a magnetic field is discussed. In the static flow, the vertical magnetic field was unable to separate the contacting magnetic particles; thus, the magnetic field cannot effectively control magnetic particles in static flows. In the planar Poiseuille flow, the free contact and separation of magnetic particles was effectively controlled by the combined action of the magnetic field and the fluid. This study provides insights into the interactions among magnetic particles in static flows and summarizes a set of methods for effectively controlling two circular magnetic particles.
Cornell potential in generalized soft wall holographic model
Authors: Afonin Sergey , Solomko Timofey
Published: August 2022

We derive and analyze the confinement potential of the Cornell type within the framework of the generalized soft wall holographic model that includes a parameter controlling the intercept of the linear Regge spectrum. In the phenomenology of Regge trajectories, this parameter is very important for the quantitative description of experimental data. Our analysis shows that the ‘linear plus Coulomb’ confinement potential obtained in the scalar channel is quantitatively consistent with the phenomenology and lattice simulations while the agreement in the vector channel is qualitative only. This result indicates the key role of the vacuum scalar sector in the formation of the confinement potential. As a by-product the overall consistency of our holographic description of confinement potential seems to confirm the glueball nature of the scalar meson f
0(1500).
Research on global calibration method of large-scene multi-vision sensors in wheel alignment
Authors: Song Limei , Wang Ruohan , Chen Enze , Yang Yangang , Zhu Xinjun , Liu Mengya
Published: August 2022

Wheel measurement and positioning technology is an important technology in vehicle production, and is of great importance for the safety of vehicles. At present, visual measurement and other methods are widely used in automotive production and inspection, but these methods are limited to the measurement of regular-sized vehicles. There is no effective solution to the problem of wheel alignment for large special-purpose vehicles with multiple tires. In order to solve the wheel positioning problem of large-size special-purpose vehicles, this paper designs a vision measurement system for wheel parameters in large scenes by combining vision sensors with linear motion guides to extend the vision measurement range and complete the global calibration of multiple-vision sensors with the help of laser trackers and self-researched stereo targets. This paper proposes an Elementary–Advance global calibration algorithm to improve the accuracy of coordinate system conversion during global calibration. This paper establishes a correction model for the measurement errors that exist in the initial global calibration process, and iterates the objective function to optimize the coordinate system conversion parameters between multiple vision sensors to improve the measurement accuracy of the system. The experimental results show that the goodness of fit and the accuracy of fit for the feature cylinder are 98.31% and 99.03% based on the global calibration method of this paper. The standard deviation of measurements for the standard ruler of the Inva alloy is less than 0.391 mm in the large dimensional range of 6050 mm × 3500 mm × 800 mm. Finally, by comparing the measurement results with the TrukCam four-wheel alignment instrument, the feasibility of the visual measurement system designed in this paper for large scenarios of wheel parameters is verified, and the measurement accuracy requirements for four-wheel alignment of special-purpose vehicles are met.
Formation and propagation of cracks in RRP Nb3Sn wires studied by deep learning applied to x-ray tomography
Authors: Bagni Tommaso , Mauro Diego , Majkut Marta , Rack Alexander , Senatore Carmine
Published: August 2022

This paper reports a novel non-destructive and non-invasive method to investigate crack formation and propagation in high-performance Nb3Sn wires by combining x-ray tomography and deep learning networks. The next generation of high field magnet applications relies on the development of new Nb3Sn wires capable to withstand the large stresses generated by Lorentz forces during magnets operation. These stresses can cause a permanent reduction of the transport properties generated by residual deformation of the Nb3Sn crystal lattice as well as the formation of cracks in the brittle Nb3Sn filaments. Studies for the development of the high luminosity LHC (HL-LHC) upgrade showed that nominal transverse compressive stresses above 150 MPa may be sufficient to generate cracks in the wires. In the case of fusion magnets, wires experience periodic bending due to the electro-magnetic cycles of the reactor which over time may induce wire deformation and filament cracks. Therefore, it has become essential to develop a quantitative method for the characterization of crack formation and propagation under compressive loads. The x-ray tomographic data of a series of restacked-rod-process (RRP) Nb3Sn wires was acquired at the micro-tomography beamline ID19 of the European Synchrotron Radiation Facility (ESRF), after intentionally inducing a broad spectrum of cracks in the Nb3Sn sub-elements. The samples were submitted to transvers compressive stresses, with and without epoxy impregnation, at different pressures, up to 238 MPa. The resulting tomographic images were analysed by means of deep learning semantic segmentation networks, using U-net, a convolutional neural network (CNN), to identify and segment cracks inside the wires. The trained CNN was able to analyse large volumes of tomographic data, thus enabling a systematic approach for investigating the mechanical damages in Nb3Sn wires. We will show the complete three-dimensional reconstruction of various cracks and discuss their impact on the electro-mechanical performance of the analysed wires.
Vortex shedding frequency of a moving obstacle in a Bose–Einstein condensate
Authors: Lim Younghoon , Lee Yangheon , Goo Junhong , Bae Dalmin , Shin Y
Published: August 2022

We experimentally investigate the periodic vortex shedding dynamics in a highly oblate Bose–Einstein condensate using a moving penetrable Gaussian obstacle. The shedding frequency f
v is measured as a function of the obstacle velocity v and characterized by a linear relationship of f
v = a(v − v
c) with v
c being the critical velocity. The proportionality constant a is linearly decreased with a decrease in the obstacle strength, whereas v
c approaches the speed of sound. When the obstacle size increases, both a and v
c are decreased. We discuss a possible association of a with the Strouhal number in the context of universal shedding dynamics of a superfluid. The critical vortex shedding is further investigated for an oscillating obstacle and found to be consistent with the measured f
v. When the obstacle’s maximum velocity exceeds v
c but its oscillation amplitude is not large enough to create a vortex dipole, we observe that vortices are generated in the low-density boundary region of the trapped condensate, which is attributed to the phonon emission from the oscillating obstacle.
Optomagnonically induced RoF chaotic synchronization
Authors: Gao Yong-Pan , Liu Xin-Chang , Cao Cong , Han Li-Hong , Lu Peng-Fei
Published: August 2022

Optomagnonics is a good platform for the interplay of radio frequency and optical signals, which are the primary communication carriers in the present day. On the basis of optomagnonics, we provide a multi-scale method for analyzing its behavior, including frequency comb and RoF chaotic synchronization at the microwave scale. Adjusting the pump light intensity permits the transition of RoF signals between harmonics, frequency combs, and chaotic movements. The dual optomagnonical device enables the synchronization of RoF signals between different cavities. Our study will contribute to the use of multiscale electromagnetic wave coupling in both conventional and quantum information applications.
Electrical characterization of the 2 × 6 × n cobweb cascaded resistor network model by the improved recursion-transform method
Authors: Li Wei-Yi , Hu Yi-Fan , Ge Huang-Rong , Ai Yi-Ran , Luo Li-Jin
Published: August 2022

Since the cobweb model combines the properties of several network topologies, the cobweb resistor network based on the cobweb model has aroused the interest of scholars. However, owing to the complicated structure of the cobweb cascaded resistor network, it is very challenging to solve with conventional approaches. To address this issue, an improved recursion-transform approach was employed. The electrical characterization of the 2 × 6 × n cobweb cascade resistor network model was studied in this paper. Firstly, the equivalent circuit of the resistor network to be solved was found. Secondly, the recursive equation of the equivalent circuit was constructed. Then, the recursive equation was linearized. Finally, the equivalent resistance of the resistor network was obtained by solving the linear recursive equation. This approach significantly reduces the computation procedure because it adopts the scheme of simplifying the circuit first, then establishing the equation and solving it. The findings indicate that the equivalent resistances between the two nodes of this resistor network change with the change of the order n. When n tends to infinity, these equivalent resistances will have definite convergence values. The calculation results show that these equivalent resistances are already very close to their convergence values, respectively, when n takes 7 or 8.
Effect of CuS buffer layer on the structural and optical properties of TeO2 nanowires: a comparative study
Authors: Alhazime Ali A , Mohamed S H , Khan Mohd Taukeer , Awad M A
Published: August 2022

The current work concerns with the effects of cupper sulfide (CuS) buffer layer on morphological, structural and optical properties of tellurium dioxide (TeO2) nanostructured thin films synthesized by vapor transport method. Single crystalline tetragonal TeO2 crystallographic phase with enhanced peak intensity and crystallinity for CuS/TeO2 film are observed by x-ray diffraction analysis. Scanning electron microscopy examinations revealed small rod-like morphology for TeO2 and randomly oriented nanowires morphology for CuS/TeO2 samples. The estimated optical band gap energies were 3.78 and 3.63 eV for TeO2 and CuS/TeO2 nanostructured films, respectively. The photoluminescence of CuS/TeO2 film was enhanced and red-shifted from 450 to 455 nm by the presence of CuS layer. The effective charge carrier life times were 0.14 ns and 1.92 ns for TeO2 and CuS/TeO2 films, respectively. These results could be beneficial for optoelectronic devices such as light emitting devices.
Magnetic moments of hidden-charm strange pentaquark states*
Authors: Gao Feng , Li Hao-Song
Published: August 2022

In this study, the magnetic moments of hidden-charm strange pentaquark states with quantum numbers

,

,

, and

are calculated in the molecular, diquark-diquark-antiquark, and diquark-triquark models. The numerical results demonstrate that the magnetic moments change for different spin-orbit couplings within the same model and when involving different models with the same angular momentum.
Magnetic dipole moments of

states
Authors: Özdem Ulaş
Published: August 2022

We systematically study the magnetic dipole moments of multiquark states. In this study, the magnetic dipole moments of possible

,

,

,

,

,

,

,

, and

states are extracted using light-cone sum rules. We explore the magnetic dipole moments of these states in a molecular picture with spin-parity

. The magnetic dipole moments of hadrons include useful information on the distributions of internal charge and magnetization, which can be used to understand their geometrical shapes and quark-gluon organization. The results of the present study along with the spectroscopic parameters may help future theoretical and experimental research on the characteristics of doubly-bottom tetraquark states.
Experimental studying the propagation and absorption of electromagnetic waves on various rock-forming minerals in Uzbekistan
Authors: Saydalimov A S
Published: August 2022

The nature of wave propagation often depends on the frequency and on the type of radiation used. The main goal of these technologies is to bring into development low-permeability isolated zones of the reservoir by exposing them to elastic waves that attenuate in high-permeability sections of the reservoir, but propagate over considerable distances and with sufficient intensity to excite low-permeability sections of the reservoir. In this paper, a more in-depth study of the propagation and absorption of electromagnetic waves through various minerals contained in rock was considered, in particular, the behavior of electromagnetic waves through rock with different moisture contents (water molecules) and clay particles (aluminosilicates) was studied. It was found that the radiative power reached the highest value at 0.01 distance, which was 506 at 10% water content, followed by 505 at 20% water content, 504 at 30% water content, 502 at 40% water content, 500 at 50% water content, and it was 498 when water content was 60%.
Results of mineralogical and geochemical investigations of rocks and ores of productive horizons of sandstone type of Dzhengeldy deposit
Authors: Khalilov A , Akbarova Z , Khoshjanova K , Atabaeva N , Juraev Sh , Juliev M
Published: August 2022

The mineralogical and geochemical study of the productive horizons of the Dzhengeldy site was carried out from 2016 to 2020. It should be noted that each horizon has ore-bearing rocks with similar mineralogical and geochemical characteristics. We studied 2 horizons of the Dzhengeldy site (Maastricht and Lyavlyakan). Below are the results of studying the material composition and geochemical features of rocks and ores from deposits of the productive horizons of the Maastrichtian and Lavlyakan selected for various geochemical subzones: oxidized (oreless, selenium dispersion aureoles, uranium and selenium dispersion aureoles, uranium dispersion aureoles, selenium ores) and unoxidized (selenium dispersion aureoles, uranium and selenium dispersion aureoles, selenium ores, uranium ores, uranium dispersion aureoles, uranium and molybdenum dispersion aureoles, molybdenum dispersion aureoles) parts of zoning. It should be noted that the subzones of uranium-selenium, uranium-molybdenum and molybdenum mineralization localized in the grey part of the section have not been studied due to the lack of samples. The subzone of the uranium-molybdenum dispersion aureoles is represented by only one sample, the subzone of the molybdenum dispersion aureoles is represented by three samples (1 sample from the Lavlyakan horizon, 2 samples from the Maastrichtian horizon).
Methodology improvement of geodetic work on the basis of geoinformation technologies
Authors: Inamov A N , Ibragimov O , Mukhamedayubova Sh
Published: August 2022

In the system of topographic and geodetic works, the introduction of modern technologies based on GPS and GLONASS satellite systems, geoinformation systems, digital and laser-electronic measuring and computing techniques, as well as laser scanning technologies is a modern requirement. Currently, the relevant authorities in the maintenance of state cadastres are working on the creation and formation of a cadastral database. In this research, the results of scientific research on the significant contribution to the development of the Republic by eliminating the inconveniences of geodetic work in mountainous areas of the Republic were given. According to the results, the resulting territorial points were combined according to a scheme (abris) created for use on the ground, and an electronic digital map of the geo-database of the region was formed.
Geoportal visualization of state cadastre objects: (a case study from Uzbekistan)
Authors: Inamov A , Sattorov Sh , Dadabayev A , Narziyev A
Published: August 2022

The Cadastre Agency under the State Tax Committee of the Republic of Uzbekistan (State Geodetic Inspection) is responsible for processing the state cadastre data of geodesy and cartography, which are part of the state cadastres, and visualizing the information in the geodata database. The State Cadastre of Geodesy and Cartography has a total of 115,616 objects in the Republic of Uzbekistan, of which 111,838 are included in the geodata database. Taking into account the transparency of this information and the fact that it is not widely used by young researchers in scientific research. During this research, proposals were developed to visualize the state cadastre of geodesy and cartography in the geoportal. During the research, world experience was studied and considered on the example of the Russian Federation, which was homogeneous in terms of systematization of geodetic and cartographic data. The created and recommended geoportal had sections on zone, column, row and nomenclature, and the zone section had rows 10N, 11N, 12N and 13N. Accordingly, the topographic map of the zones was provided with space and cartographic bases.
Integral indicators of the ecological and biological state of soils in Jizzakh steppe, Uzbekistan
Authors: Makhkamova D , Gafurova L , Nabieva G , Makhammadiev S , Kasimov U , Juliev M
Published: August 2022

In the study of soil fertility, biological factors, especially the microbiological activity of soils, have recently attracted increasing attention. Agronomically important groups of microorganisms that participate in the nitrogen and carbon cycle play an important role in soil fertility. By the number of these organisms, it is possible to indicate the state of the soil and characterize the direction of the processes occurring in it. In this regard, it seemed to us necessary to carry out a quantitative account of the main physiological groups of microorganisms involved in the transformations of nitrogen- and carbon-containing substances. The studied area is included in the semi-desert serozem zone with its characteristic geomorphology, climate and vegetation cover. Agrochemical, agrophysical, physical and chemical properties and the sum of integral indicators of the ecological and biological state of soils, it makes it possible to determine the level of impact of their ecological and genetic properties, as well as natural and environmental factors on soil fertility and land degradation.
Selection of partenogenetic clones for mixing with fine silkworm breeds in the conditions of Uzbekistan
Authors: Daniyarov U , Navruzov S
Published: August 2022

The creation and introduction into production of new breeds and hybrids that meet the needs of the world market and industrial enterprises through the development of selection methods for breeding stations and seed enterprises is of great scientific and practical importance. In this regard, the work of a number of local and international scientists is devoted to the selection and creation of new breeds and hybrids of mulberry silkworm on the basis of leading selection traits. The effectiveness of the artificial parthenogenesis method developed in our laboratory is that the effect applied suppresses the reduction division of egg cells. Also, the parthenogenetic genus immediately receives the same set of chromosomes and genes. However, ♀ clone × ♂ hybrid worms have a high viability, the cocoons are the same in shape and other characteristics, there is no work on the separation of the primary parent breed (parthenoclonus) for hybridization (because it consists of 100% only females), breeding at all stages work is not done (because all parthenoclon females are genetically the same and do not change by generation). It is also possible to obtain all the cocoons of parthenoclon in the extraction of cocoons, as their genetic homogeneity completely eliminates the sorting of cocoons in breeding stations and seed plants.
Influence of phosphorus fertilizers on the yield of soybean varieties in the conditions of Uzbekistan
Authors: Atabayeva Kh N , Yakubov S Sh
Published: August 2022

Soybean varieties are being studied in Uzbekistan, and cultivation technologies are being improved and new ones are being created. In this research, the effect of phosphorus fertilizers on soybean varieties was studied in the conditions of meadow-swamp soils of Tashkent region. The field experiments were carried out in 4 rows, the piles were 20 m long, 3.6 m wide, with 6 rows, of which 2 rows were marked in the middle and 4 rows were marked as protective rows at the edges. The results showed that when the norm of nitrogen and potassium-based phosphorus fertilizers was 80 kg, the leaf surface averaged 42.6 thousand m2/ha in the Nafis variety. In the second variant, when the phosphorus content was increased to 40 kg, the leaf surface was found to be 2,000 m2/ha higher. In the Vilana variety, the leaf surface area was 42.4 thousand m2/ha at low phosphorus levels, while the leaf surface was found to be 2.2 thousand m2/ha when the phosphorus level was increased by 40 kg.
Representatives of Lepidoptera groups in the biotecenosis of Uzbekistan and their effective parasite-entomophage types
Authors: Jumaev R , Rustamov A
Published: August 2022

In this article, we traced the development of fauna, bioecology and populations of more than 50 species of the main family Lepidoptera, found in the biocenosis of Uzbekistan. Research has been conducted in agricultural crops, forestry and natural biocenoses, and representatives of the Lepidoptera family have been involved in scientific research on species that cause great economic damage. Trichogrammatidae, Braconidae, Ichneumonidae, Chalcididae, Pteromalidae, and Tachinidae, the main entomophagous species that effectively control the number of members of the Lepidoptera family, have also been identified and systematically analyzed. The representatives of the family Trichogrammatidae, which are effective parasitic entomophagous in the management of the number of representatives of the family Lepidoptera. The study revealed that in the agrobiocenoses of cotton, mung bean, corn and cabbage in Tashkent province, the level of occurrence of three main species of nightshade pests of the family Trichogrammatidae, which are egg parasites of the family Lepidoptera, was determined. This means that the number of nights can be effectively controlled by members of the trichogramma family.
Effectiveness of application of mineral fertilizers in growing food plants in desert pasture conditions of Uzbekistan
Authors: Namozov N , Teshaboev B , Saidova M , Kodirova D , Usmanova M , Tursinbaev M
Published: August 2022

Pastures are the main source of fodder for the desert livestock of the country and can be used all year round. Pasture fodder is the cheapest source of fodder. This research work focused on the effectiveness of the use of mineral fertilizers in the cultivation of forage crops in desert pastures, phenological observations of desert forage plants, the determination of the amount of macronutrients in the vegetative organs of desert forage plants. Based on the results, one of the most effective ways to get high yields from desert forage plants was the use of mineral, local, micro and bacterial fertilizers. Moreover, it was found that preventing the degradation of sandy desert soils and improving fodder production for livestock depended on the planting and care of high-yielding desert forage crops, mainly in desert pastures. In general, the use of agro-technical measures was aimed at preventing the degradation of sandy desert soils and improving natural pastures, ensuring the germination of seeds of various desert forage plants in sandy desert soils, achieving growth and accumulation of high nutrient mass, and using mineral forage plants.
Development factors of the state of the livestock sector in Uzbekistan
Authors: Dosmukhamedova M H
Published: August 2022

In each district of Uzbekistan, 3,000 inter-farm fattening enterprises have been established, and the weight of young cattle has reached 450-550 kilograms. Large quantities of beef were produced. It should be noted that the largest industrial complexes (10,000 heads) have been operating effectively. In this research, the state and development of animal husbandry in Uzbekistan for 1985-2017, issues of selection and breeding of cattle, the use of feed resources, the results of the privatization of livestock facilities and animals were studied. Besides, different fodder crops, including alfalfa (hay), oats, feed peas, barley, maize (for silage and grain), seed for intermediate crops, and soybean, were studied and analyzed in term of structure of arable land (%), arable land (ha), productivity (quintals/ha), gross yield (tons). According to the results, the area of land allocated to livestock farms with 500 head of cattle, including 200 cows (380 conditional cattle), was 115 hectares (0.30 hectares for each conditional cattle). According to the results of the experiment, it was proposed to plant alfalfa in 25% of this fodder area and intermediate and secondary fodder crops in 75%.
An overview of the environmental impact of coal industry waste
Authors: Straupnik I A
Published: August 2022

In this paper the actual statistical data on the topic of coal industry waste accumulation in the Russian Federation are given. Also, the basic consequences of waste accumulation for the natural environment are considered and quantitative data are outlined.
Method of estimating fuel combustion efficiency at a boiler house
Authors: Gordin S A , Shamak V A , Berdonosov V D
Published: August 2022

There are various ways to estimate fuel combustion efficiency of a boiler house. Most of these ways are based on complex instrumental measurements and are not always applicable in practice. Batch feeding of fuel into a boiler furnace makes it difficult to accurately determine fuel combustion speed and, correspondingly, the amount of heat released during combustion. The method of estimating fuel combustion efficiency at a boiler house considered here allows to determine actual fuel combustion speed by visual observation.
Modeling the prediction of water and steam quality in a power unit
Authors: Yegoshina O V , Lin Ted Wei , Zvonareva S K
Published: August 2022

In this article, mathematical models based on the material balance equations for the drums of the low and high pressure circuit of the heat recovery boiler are compiled. Investigated impurities: sodium, silica, iron. For the equation for the concentration of iron, the coefficients of the rate of formation and flushing of deposits proposed by the authors are taken into account. The concentrations of impurities obtained according to the developed models in controlled streams were studied: feed and boiler water, saturated steam. The calculation results are compared with industrial data. It was found that the error does not exceed 20%, which confirms the possibility of using the developed mathematical models in cycle chemistry. These algorithms reduce the volume of measured water and steam quality indicators and facilitate the work of operational personnel.
Mathematical modeling of greenhouse-livestock complex heated by solar and bioenergy sources
Authors: Ergashev Sh H , Fayziev T A , Tilavov Yu S , Sattorov B N , Khidirov M M , Mirzayorova S U
Published: August 2022

The article develops a mathematical model of the heat supply system of the greenhouse complex, taking into account the free heat flow in the animals, solar energy, heat energy stored in heat accumulators and developed through the program MATLAB / Simulink. In the development of a mathematical model of the heat supply system of the greenhouse complex, a block diagram of the equation in the program MATLAB / Simulink was developed, without taking into account the change in air density and specific heat capacity with temperature. According to the graphic results obtained for the daily value of solar radiation 500 W/m2, outside air temperature, -6 °C in Karshi, the air temperature inside the greenhouse rises to 22 °C, water tank battery temperature to 13 °C, underground heat accumulator temperature to 17 °C. can be seen. while the amount of total solar radiation was 300 W/m2, this figure was found to be 14 °C, 9 °C, and 12 °C.
Orbital Change of belt for Metal V-belt Type CVT (Continuously Variable Transmission) - Change of pitch angle at strings -
Authors: Oshima Kazuki , Mitsubayashi Seiji , Obunai Kiyotaka , Okubo Kazuya
Published: August 2022

The object of this study is to investigate the orbital change of belt with the increase of the transfer torque, during steady-state belt of rotation using a bench-type CVT testing machine. Acceleration sensors were attached to the V-belt to measure accelerations of each element. The pitch angle of each element at the strings also near the entrances and exit was continuously measured by calculating the 3-axis accelerations during the belt travel. Macroscopic change of pitch angle was almost followed by the geometrical change of the angle during the orbital motion of the belt. However, local change of pitch angle at near the entrance and exit of the pulley was not explained by the angle of the geometric posture movement of elements. The pitch angle of each element was locally increased near the entrance and exit of the driven pulley as the load torque increased, while the opposite tendency was observed near those locations of the driving pulley.
Conversion of Steel Converter Slag into Anion Removing Agent via Alkali Fusion
Authors: Wajima Takaaki
Published: August 2022

Steel converter slag, a by-product of iron- and steel-making plants, was converted into a product containing hydrocalumite-like compound using the alkali fusion method. Most of the crystalline phase in the converter slag was converted into a soluble phase by the fusion method, and could be transformed into a product which included hydrocalumite-type crystals. The ability of the product to remove BO3
−, F−, PO4
3−, AsO2
−, AsO4
3−, SeO3
2− and SeO4
2− from aqueous solution is higher than that of raw slag, especially for BO3
−, AsO2
−, AsO4
3− and SeO3
2−.
High-performance dielectric nano-cavities for near- and mid-infrared frequency applications
Authors: Hoang Thanh Xuan , Chu Hong-Son , García-Vidal Francisco J , Png Ching Eng
Published: August 2022

We present a judicious design approach for optimizing semiconductor nanocavities, starting from single photonic atoms to build photonic molecules functioning as high-performance nanocavities. This design approach is based on exact analytical solutions to the Maxwell equations for collective Mie resonances. Conceptually, we distinguish different concepts of cavity modes including Mie mode, collective Mie mode, photonic-crystal (PC) band-edge mode, and Feshbach-type bound states in the continuum (BIC) mode. Using the design approach, we present a unique structure of nanocavity supporting the Feshbach-type BIC mode, capable of enhancing the emission rate of a dipolar emitter by orders of magnitude. This high-performance nanocavity suppresses radiative loss channels strongly via destructive interference and consequently channels the emission light efficiently into an in-plane bi-directional beam with a divergence angle of 10°. Engineering the geometrical parameters of the nanocavity for near-infrared frequency applications requires a fabrication tolerance of ±5 nm. This high accuracy is challenging for the mass production of devices. The fabrication accuracy can be relaxed greatly for mid-infrared frequency devices. As a showcase, we analyze and optimize the well-known PC L3 defect nanocavity for mid-infrared frequency applications in the framework of Feshbach resonance. We show that the optimal structure of this defect nanocavity requires a fabrication tolerance of ±50 nm. Our nanocavity design approach may be useful for near- and mid-infrared frequency applications.