bluuebunny/crossref_metadata_2025 huggingface dataset:
Sliding bearings with lead-bismuth liquid metal lubrication
Authors: Roshchin M N
Published: December 2022

The article presents the results of tribological tests of a thrust bearing made of steel-bronze materials when lubricated with a lead-bismuth metal melt under conditions of heating up to 500°C. The influence of steel-bronze on the coefficient of friction in the ranges of load 0.17–1.0 MPa, velocity 0.05–0.23 m/s, and temperature 250–500°C was studied. It has been established that the tribological properties of friction pairs under experimental conditions mainly depend on temperature, which determines the wetting angle and the viscosity of the metal melt. With an increase in the temperature of the melt above 300°C, the viscosity of the melt decreases, and the liquid metal lubricant is squeezed out of the actual contact areas.
Study of the passive method of induced polarization at the copper deposit “Zhaman-Aibat”
Authors: Belolipetskii P V , Potylitsyn V S , Shajdurov G Y , Maykov O A , Kokhonkova E A , Krasnov T V , Dashkova A K
Published: December 2022

The article presents data from field experimental observations using the passive method of induced polarization, at the Zhomart mine (Zhaman-Aibat deposit, Republic of Kazakhstan) on September 7-8, 2021. Profiling was carried out with a step of 50 meters, non-polarizing electrodes of the “VITR” brand were used as electrodes. The signals were recorded using a specialized precision 24-bit analog-to-digital converter. In the course of field observations, a profile characteristic was obtained in terms of the induced polarization parameter. An analysis of the profiling graph shows that the obtained profile characteristic marks the presence of an ore body with two peaks with values of 0.35 and 0.32, which, when using a three-electrode differential setup, indicates the presence of polarization anomaly boundaries. Thus, the passive method of induced polarization makes it possible to register ore anomalies down to a depth of 600 m and makes it possible to detect copper-bearing ores.
Making amendments to CNC machines in order to improve manufacturing accuracy
Authors: Kiseleva A I , Barbashov N N
Published: December 2022

New methods are needed to be developed to improve the accuracy of equipment, due to the fact that requirements for the accuracy of products with complex configurations manufactured on CNC machines have increased and it is necessary to reduce metal consumption in their production. One of the ways is to purposefully influence the process of equipment development: designing a rational layout of the machine, choosing modern materials, precise manufacturing of components. The method is effective, but it is associated with high economic costs. Currently, mathematical and statistical methods of quality management at an industrial enterprise are becoming increasingly widespread. The possibility of forming a conclusion about the total set of manufactured products based on several observed in the sample is important for the continuation of the production process and compliance with the specified quality criteria. Statistical regulation of this characteristic is the current control over production and the prevention of defects by timely intervention in the technological process.
Modeling the influence of heat sinks on the structure of the temperature field of a profile heat pipe
Authors: Petrov D A , Karachinov V A
Published: December 2022

Within the framework of a computer experiment using the finite element method, a technique has been developed graphical representation the structure of the temperature field of a heat pipe with active-type defects - heat energy sink, localized in the body between the ribs. It is shown that when the pipe start-up mode is implemented and certain heat energy sink power, a typical isotherm shape with a concave front is formed. The passage by the isotherm heat energy sink of a round form is accompanied by the formation of a local isothermal circuit. Significant variability of the shape of the isotherms is noted.
Development of the installation and experimental research of the patterns of change in influencing factors in the process of tomato drying
Authors: Rasulov Shukhrat , Artikov Askar , Abidov Kamiljan , Djuraev Khayrullo
Published: December 2022

Annotation. The scientific research illustrates that experimental installation of a cylindrical type for the combined drying of highly moist agricultural products, using the example of a tomato, the regularities of the course of mass transfer processes are studied and the technological process is described. In order to determine the main influencing parameters in the process of drying tomatoes grown in a regional climate, an effective method of heat transfer system was used to study the kinetics of dehydration of wet material. A plan of a multifactorial experiment was developed, on the basis of which the boundary conditions of the influencing factors on the drying process were determined, with the study of the mechanism of moisture mixing over the layers of the material, a tomato drying curve was constructed depending on time, as well as the amount of energy consumed to remove 1 kg of moisture from the dried material.
Experimental determination of the law of vibration of the improved jet mechanism of the sewing machine
Authors: Mavlonova Iroda , Fayziev Sirojiddin , Rakhimov Khakimboy , Vokhidova Munira
Published: December 2022

The article presents the results of experimental determination of the oscillation law of the proposed additional conical spring mechanism of the effective reaction. The results of calculation of compressive strength and spring elasticity are presented. The change in the force acting on the reaction is determined by the electrostrain method and is based on its parameters.
Mathematical modeling of factors influencing the process of filling karakul semi-finished products
Authors: Kazokov Farkhot , Kodirov Tulkin
Published: December 2022

This article discusses the results of research aimed at solving the problem of increasing the operational durability of dressed astrakhan fur in a fur coat. To solve it, an approach was chosen based on an understanding of the physicochemical processes occurring in the material under the influence of operational factors. The use of the developed method, which gives an unambiguous assessment of the material, made it possible to investigate the dependence of the durability of the material on the parameters of the technological process of its manufacture.
Instrumentation complex for measuring the thermophysical properties of rocks in natural occurrence temperature conditions
Authors: Kalyak A A , Kazantsev S A , Gruznov V M , Zasypkina I I
Published: December 2022

A schematic diagram and an operation algorithm of an instrumentation complex for measuring the thermal conductivity and thermal diffusivity of rocks by the non-stationary method of a linear source under natural occurrence temperature conditions up to 200 °C are proposed. Thermocouples are used to measure the temperature of the probes. The complex contains two linear (needle) probes, which are placed in a rock sample at a certain distance r from each other. One probe, containing a linear heater and a thermocouple, radiates heat, the other one, containing a thermocouple, is a measuring probe. The cold junction temperature of thermocouples is measured by a semiconductor sensor. To calculate the voltage of the cold junction from the value of its temperature, a direct conversion of thermoEMF by a power polynomial is used. To calculate the temperature of the hot junction of the probe, an inverse transformation by a power polynomial of the voltage values of the hot junction of thermocouples into temperature was applied. In direct and inverse transformations, the degree of polynomials is 10. To reduce the temperature measurement error, digital filtering of signals from thermocouples was used. A digital-to-analogue converter is included in the heater circuit of the radiating probe for flexible heating control. The results of measuring the thermal conductivity and thermal diffusivity of dry and wet sand samples are consistent with the literature data on the temperature dependence.
Improved dusty gas cleaning in open-cast automobile transport
Authors: Zinurov V E , Kharkov V V , Madyshev I N , Dmitrieva O S , Dubkova N Z
Published: December 2022

Service life extension of internal combustion engines is an urgent task for open-cast automobile transport. Dust contamination of oil and constructive elements of the internal combustion engine accelerates its wear and tear, resulting in breakage. The authors developed a separation device with sections of double-T elements as a replacement for the first stage cleaning device in open-cast automobile transport. Numerical results show that the proposed separation device provides gas cleaning with high efficiency from fine, medium, and coarse solid particles. The use of this device improved the overall efficiency of gas cleaning and extended the service life of the fine filter, which has a positive effect on the internal combustion engine. Studies have shown that the separation device has an average efficiency of 81.2% with the following parameters: dust particle size 5–20 μm, dust particle density 1000–7000 kg/m3, inlet gas velocity 3–15 m/s.
Experimental work on determining the coordinates of an underground active vibration sensor for diagnosing main pipelines
Authors: Kokhonkova E A , Maykov O A
Published: December 2022

The article deals with the problem of determining the location of the main underground pipelines, using the method of subsurface location. To date, the problem of registering the deviation of the location of underground pipelines from the design one, in the conditions of the Far North, when laying pipelines in unstable soils, remains relevant. The displacement of the pipeline in the ground leads to the formation of stressed sections of the pipeline walls, in which cracks may form, followed by leakage of oil products into the environment.
Multispectral lidar method for monitoring the forest ecosystem under the forest canopy
Authors: Belov M L , Belov A M , Gorodnichev V A , Alkov S V , Ivanov S E , Shkarupilo A A
Published: December 2022

This study demonstrates the potential of the multispectral lidar method to monitor the forest ecosystem under the forest canopy. The mathematical modeling results of forest territories elements classification on the created neural network using experimentally measured reflection coefficients are presented. It is shown that the neural network provides a high probability of correct classification for the forest ecosystem elements classification task (when using lidar measurement data about the height of the forest ecosystem elements). Laser pulse sounding at two wavelengths in near infrared spectral range 1064 and 2030 nm and the created neural network provide the probabilities of correctly classify the undergrowth of green broadleaved and coniferous trees, swamps and soils more than 0.84 and the probability of incorrect classification less than 0.08.
Changes in the absorption coefficient of solar spectrum concrete over time under variable technological factors and introduced color compositions into the concrete mixture
Authors: Usmanov Farkhod , Usmanova Gulrukh , Sadikov Mizrob , Kakhhorov Hamid , Yakhshiev Yokub
Published: December 2022

The absorption coefficient of concrete from different wavelengths of the solar spectrum has been studied for varying technological factors. Experimental studies have established a pattern of changes in the absorption coefficient of freshly laid concrete over time.
Analysis of modern methods of determination of mechanical status and diagnostic models of power transformers
Authors: Fazliddinov Salokhiddin , Kuchkarov Behzod , Sharibaev Nosir , Abdulkhaev Abror , Tulkinov Mukhammad-Ali
Published: December 2022

The development and modernization of methods for analyzing the mechanical condition of power transformer windings remains an urgent task. The main reason for this is that many interruptions in the electrical system are caused by faults in the windings of power transformers. With this in mind, we have developed methods for analyzing the mechanical condition to overcome these shortcomings and recommend its application in practice. It should be noted that the assessment of the state of the number of coils by the method of frequency reaction analysis is the most promising direction in the field of packaging diagnostics this method provides the best sensitivity to changes in the geometric dimensions of the packaging reflected.
Stability of a weakly collisional plasma with runaway electrons
Authors: Grasso Daniela , Borgogno Dario , Singh Lovepreet , Subba Fabio
Published: December 2022

We investigate the problem of the tearing stability of a post-disruption weakly collisional plasma where the current is completely carried by runaway electrons. We adopt here a two fluid model which takes into account also ion sound Larmor radius and electron inertia effects in the description of the reconnection process. In the past, it has been demonstrated in [Helander et al. Phys. Plasmas
14, 12, (2007)] that in the purely resistive regime the presence of runaway electrons in plasma has a significant effect on the saturated magnetic island width. In particular, runaway electrons generated during disruption can cause an increase of 50% in the saturated magnetic island width with respect to the case with no runaway electrons. These results were obtained adopting a periodic equilibrium magnetic field that limited the analysis to small size saturated magnetic islands. Here we present our results to overcome this limitation adopting a non-periodic Harris’ type equilibrium magnetic field. Preliminary results on the effects of the ion sound Larmor radius effects will also be presented.
Resonant transport of fusion alpha particles in quasisymmetric stellarators
Authors: Albert C.G. , Rath K. , Babin R. , Buchholz R. , Kasilov S.V. , Kernbichler W.
Published: December 2022

In modern, highly optimized stellarator configurations where prompt fusion alpha particle losses from the plasma core are absent, alpha particles can still be lost due to stochastic orbits which result in delayed losses. One mechanism leading to stochastic orbits are changes in the particle trapping class during drift motion along the contours of the parallel adiabatic invariant J
∥ leading to jumps in J
∥ when crossing class boundaries. Another mechanism, which is of main interest here, is the resonance between particle drift and bounce motion (drift-orbit resonance). The first mechanism affects mainly trapped particles near the trapped-passing boundary in the phase space of quasi-symmetric and quasi-isodynamic devices, and can be minimized there by aligning local magnetic field maxima on a given flux surface. The second mechanism may affect a broader range in the trapped particle domain where contours of J
∥ still remain closed. Drift-orbit resonances modify the topology of orbits leading to island-like structures on Poincaré plots where these islands may overlap thus leading to the stochastic transport. In this report, we study this stochastization mechanism in quasi-symmetric stellarator configurations with help of the Hamiltonian drift-kinetic code NEO-RT as well as orbit classification and direct computation of fusion alpha losses within the symplectic orbit following code SIMPLE. The width and overlap of resonances in phase-space is studied using Hamiltonian perturbation theory. Based on optimized reactor configurations we assess if this approach can be used as a fast metric for fusion alpha losses in stellarator optimization.
Role of avalanche transport in competing drift wave and interchange turbulence
Authors: Ghendrih Philippe , Dif-Pradalier Guilhem , Panico Olivier , Sarazin Yanick , Bufferand Hugo , Ciraolo Guido , Donnel Peter , Fedorczak Nicolas , Garbet Xavier , Grandgirard Virginie , Hennequin Pascale , Serre Eric , Tamain Patrick
Published: December 2022

We complete the 2D 2-fields turbulence model previously used with an interchange-like instability by slightly modifying the parallel loss terms to drive drift wave instabilities. We show that the instability driven by temperature fluctuations of the sheath losses is identical to that of the drift wave turbulence. The linear analysis is performed and used to select control parameters that yield identical maximum growth rates for the interchange alone and drift wave alone instability. Combining the two instabilities doubles the maximum growth rate. The non-linear simulations are used to analyse the SOL width. The simulations allow one to identify a low field side SOL region where interchange and drift wave are unstable and a high field side SOL region where only the drift wave is unstable. The SOL profiles appear exponential in the region close to the source but depart from a simple exponential fall-off in the far SOL. The low field side SOL width is found to be larger in the interchange alone case, slightly smaller when both instabilities are present and finally narrower when only the drift waves. For the high field side SOL, without interchange, the drift wave SOL width is observed to be identical to that on the low field side and larger than that when both instabilities at play. The Sherwood dimensionless parameter, ratio of convective particle flux divided by the diffusive particle flux, is used to compare the efficiency of turbulent transport. The profiles of the Sherwood parameter for time and flux surface averaged transport indicate that turbulent transport is dominant close to the separatrix but is less effective towards the far SOL. The Sherwood parameter evolution, determined with the flux-surface averaged transport, indicates that outward avalanche transport with corrugations governs the case with interchange only. When combining the two instabilities, outward avalanche transport is less pronounced and inward avalanche transport is observed, reducing the overall turbulent transport efficiency. The avalanche transport with drift waves only compared to interchange only is found to be inhibited.
On the vertical and horizontal profiles of the atmospheric electric field during thunderstorms
Authors: Chilingarian A , Hovsepyan G , Karapetyan T , Sargsyan B , Zazyan M
Published: December 2022

We present the first results of a new experiment on Mt. Aragats for measuring the horizontal profile of atmospheric electric fields during thunderstorms. Networks of advanced particle spectrometers operated on the slopes of Mt. Aragats continuously measure fluxes of charged and neutral particles, periodically registering impulsive enhancements, so-called Thunderstorm Ground Enhancements (TGEs). This gives the possibility to estimate the strength of the electric field in the lower atmosphere. Relativistic Runaway Electron Avalanches (RREAs) are registered by the particle detectors located on the Earth's surface as TGEs sometimes exceeding the fair-weather fluxes up to a hundred times. The strong accelerating electric field can reach 1.7-2.2 kV/cm at altitudes 3-6 km, and extend down to 50-150 m above the Earth's surface. The horizontal extent of the electric field can reach 10 km and more.
Classification and Reconstruction of single and multiple ELVES in AUGER
Authors: Mussa R , Vasquez A.
Published: December 2022

ELVES have been regularly studied since 2013 with the twenty-four telescopes of the Pierre Auger Observatory, exploiting a dedicated trigger and extended readout. A large fraction of the observed events shows double ELVES within the time window, and, in some cases, even more complex structures are observed. We classify double ELVES using the radial variation of the time gap and the photon flux ratio between flashes. Such parameters may be related to the different types of lightning in which they originated. We will review the cross correlations of the ELVES light emissions with the radio waves detected by the antennas of the ENTLN network, active in Argentina since late 2018. Further improvements of our detection and classification algorithms were achieved by detecting ELVES from closer lightning: since December 2020, the ELVES trigger was extended to the three High Elevation Auger Telescopes (HEAT), which observe the night sky at elevation angles between 30 and 60 degrees, with an enhanced time resolution (50 ns time binning). Both single and double ELVES are recorded with unprecedented time and space resolution. Events from the first year of data taking will be shown.
Seven years of quasi-continuous LIDAR data
Authors: Gaug Markus , Hahn Alexander , Acciari Victor , Besenrieder Jürgen , Prester Dijana Dominis , Dorner Daniela , Fink David , Font Lluís , Fruck Christian , Mićanović Saša , Mirzoyan Razmik , Pavletić Lovro , Schmuckermaier Felix , Will Martin
Published: December 2022

We have analyzed seven years of quasi-continuous LIDAR data taken during those nights when the MAGIC telescopes were operating. Characterization of the nocturnal ground layer is possible through an absolute calibration of the LIDAR during clear nights and yields zenith and azimuth-angle dependent aerosol extinction scale heights for clear nights. We derive aerosol transmission statistics for light emitted from various altitudes throughout the year and separated by seasons. We find further seasonal dependencies of cloud base and top altitudes. The Cumbre Vieja volcano dust plume observation is shown to highlight the possibilities and limitations of our method.
Assessing aerosol induced errors in Monte Carlo based air-shower reconstruction for atmospheric Cherenkov detectors
Authors: Holch T L , Leuschner F , Schäfer J , Steinmassl S
Published: December 2022

Aerosol levels influence the wavelength dependent transmission properties of the atmosphere. Variations in aerosol levels therefore affect the amount of Cherenkov light from air-showers that can reach an atmospheric Cherenkov detector. As the amount of detected Cherenkov light is directly related to a primary shower particle’s energy, deviations between actual and assumed atmospheric transmission properties yield errors in reconstructed particle energies as well as energy axes of instrument response functions. In this work, a scheme is presented to assess this influence and potentially reduce related errors in the air-shower reconstruction. The proposed scheme relies on estimations or measurements of the aerosol optical depth and atmospheric density profile which are then used in radiative transfer simulations to generate atmospheric transmission profiles. As the scheme furthermore uses detector specific quantum efficiencies and generalised shower evolution models, it does not rely on detailed Monte Carlo simulations for the different atmospheric conditions but only on the transmission profile which the initial shower reconstruction algorithm is based on. The approach is derived and presented on the example of the H.E.S.S. experiment which employs imaging atmospheric Cherenkov telescopes in the Khomas Highland of Namibia to detect gamma rays in the GeV to TeV energy range.
Remaining Useful Life Prediction Based on CNN-BGRU-SA
Authors: Sun Junjie , Zheng Lehui , Huang Ying , Ge Yu
Published: December 2022

Remaining Useful Life (RUL) prediction has very high importance for improving the safety and reliability of equipment, and its accurate estimation can provide technical support for fault Prognostics and Health Management (PHM). A hybrid deep neural network model has been proposed to improve the prognosis accuracy of equipment RUL. Convolution Neural Network (CNN) is used to extract the local features with Bidirectional Gated Recurrent Unit (BGRU) capturing the anterior and backward long-term dependence and then Self Attention (SA) assigning weights. Finally, Fully-Connection Network (FCN) is stacked to output the RUL prediction value, and its superiority is verified on C-MAPSS dataset. Experimental results show that CNN-BGRU-SA acquires better prognosis performance compared with a single network and the approach based on the BLCNN model, with high accuracy and generalization.
Design of a Curved Surface Adaptive Permanent Magnet Wall Climbing Robot
Authors: Zhu LuShan , Zheng XiongSheng
Published: December 2022

At present, there are more and more wall climbing robots applied to metal surfaces at home and abroad, and traditional wall climbing robots can no longer meet the needs of reality. In this paper, a wall climbing robot structure based on a flexible track with variable curvature is designed. By increasing the contact area between the caterpillar and the contact surface, the structure principle, static analysis, and simulation of the influence of wall thickness and air gap on the adsorption capacity of the permanent magnet are introduced. The prototype is manufactured to verify its feasibility. The result proves that. The wall climbing robot designed in this paper can move with the load on the variable curvature elevation and has a certain adaptive ability of variable curvature and obstacle surmounting ability.
Research on Intelligent Vehicle Trajectory Tracking Control
Authors: Zhu Boqing , Du Feng , Shi Zhehui , Liu Chang
Published: December 2022

In order to make the trajectory tracking of the intelligent vehicle has good tracking accuracy. In this article, a horizontal and vertical cooperative control strategy is proposed. This measure takes vehicle dynamics model as the research object, and the feedforward control is added to the lateral controller to make up for the deficiency of LQR tracking. The longitudinal dual PID control algorithm is used to track the trajectory of the intelligent vehicle in the longitudinal controller. In CarSim with Simulink environment set up a simulation model of the design of five polynomial trajectory simulation experiments. The experimental results show that in low-speed real driving conditions, this control method has better tracking accuracy and stability in tracking there is very good.
Design and Research of Test Bench for Loading and Performance Testing of Aerospace Precision Ball Screw
Authors: Zhanga Yang , Fan YuanXun , Xu LuHui
Published: December 2022

Aiming at the problem of insufficient research on the motion failure caused by the degradation of the grease of the precision ball screw pair under the typical working conditions of high frequency and high load in aerospace, a set of high frequency inertial loading test bench is designed. Loading and performance testing functions are integrated. The mechanical structure of the test bench, the inertia adjustment device and the connecting member of the pendulum rod are designed, which can simulate the loading under aerospace conditions. Installing multiple sensors can test the force response characteristics, vibration characteristics, temperature rise characteristics and transmission efficiency of the precision ball screw pair when it operates under different frequencies and different axial forces. The axial force of the nut with different rotational speeds under inertial load is tested by experiments.
Accuracy Analysis of Timing Comparison for BDS-3 and GPS Based on Satellite Common View Algorithm
Authors: Zhou Mingduan , Ji Xu , Zhang Muyuan , Tian Ye , Shang Leyi
Published: December 2022

With the networking completion of the Beidou navigation satellite system (BDS-3), the BDS-3 system was opened in the whole world on July 31, 2020. It is important practical significance to analyze the performance of the BDS-3 system and the GPS in terms of satellite common view timing comparison. In order to analyze the accuracy of timing comparison for BDS-3/GPS global navigation satellite system common view time, the comparison experimental of BDS-3/GPS with medium and long baseline is carried out based on satellite common view algorithm by using the National Metrology benchmark system of atomic time scale maintained by National Institute of Metrology (NIM), China. The timing model and algorithm of the BDS-3/GPS satellite common view algorithm are deduced in detail, and the stability of receiver clock difference and accuracy analysis of timing comparison for the BDS-3/GPS based on the satellite common view algorithm are compared and analyzed. The experimental results show that the stability of receiver clock difference of BDS-3 and GPS is respectively ns-level, but the stability of receiver clock difference of BDS-3 system is slightly better than that of GPS; the accuracy analysis of timing comparison for BDS-3 and GPS based on satellite common view algorithm is respectively better than 24 ns, but the accuracy analysis of timing comparison for BDS-3 system is slightly better than that of the GPS.
Based on Wavelet Threshold Denoising-LDA and Bilstm Aircraft Engine Life Prediction
Authors: Li Honglin , Wang Jiaxi
Published: December 2022

Turbine engines operate in extreme environments and require regular maintenance and replacement. It leads to a lot of human and financial investment, and once the aircraft fails during the navigation process, it will cause irreparable losses. Therefore, it is very necessary to propose an engine life prediction model, which can intervene manually before the engine fails, thereby reducing the probability of an air accident. In order to solve the problem, this paper proposes a wavelet threshold denoising-LDA and Bilstm aero-engine life prediction method, and uses the C-MAPSS data set for simulation prediction. Based on this data set, this paper firstly carried out wavelet threshold denoising to the data set to remove noise, and then used LDA to reduce the dimension to screen out the main features. The processed features are input into the bidirectional LSTM network for prediction. By training the above preprocessed data, BIlstm has better adaptability than the convolutional neural network CNN and LSTM, and the prediction error is greatly reduced.
Optimal Numbers and Mix of SSA Drones and Radio Repeater Drones based on Ant Colony Algorithm
Authors: Yu Shu , Wang Haiying , Zheng Luo
Published: December 2022

During the 2019-2020 fire season in Australia, there were destructive wildfires in every state, particularly in Victoria. Therefore, we are required to build a model to deploy drones to surveil the fire. We develop the basic model to find out the optimal numbers and mix of SSA drones and radio repeater drones. First, we use Ant Colony Algorithm to solve the shortest path, which could make the government purchase as few drones as possible under the premise of covering a large area. According to the operating mode of UVA and the theory of UAV formation cooperative control, we find out the information state of the radio repeater and its cruise path length. Besides, we create a fire risk assessment to determine the speed of information updates and adjust the number of drones. Finally, we determine the optimal combination of 1260 SSA drones and 151 repeater drones.
Research the SDRAM Controller Based on FPGA
Authors: Gao Jinggang , Gao Yunxia
Published: December 2022

A global SDRAM controller was designed based on FPGA. The major components of the controller include the interface control module, the command generation module, the data path module, and the source program simulation using Quartus II. From the simulation results, the soft core of the SDRAM controller could complete the mode setting, normal R/W operation, and auto-refresh function. It could easily meet different needs by simple modification, and it is much more flexible and programmable.
Nonuniform ISRJ suppression based on time shift alignment and morphological processing
Authors: Zhang Haiqing , Zhu Yongfeng , Feng Jiamei , Fu Qiang
Published: December 2022

Non-uniform interrupted-Sampling Repeater Jamming is a coherent interference technology based on the principle of undersampling, and it has a salient feature over several uniform interferences in terms of pseudo-randomness, which makes it more difficult for radar to detect real targets. Aiming at the target detection problem of non-uniform interrupted-sampling repeater jamming, a method for radar based on time-frequency domain interference suppression is proposed in this paper. Firstly, according to the short-term Fourier transform strategy, the echo signal is converted to the time-frequency domain, and then we select one of the columns in the time-frequency matrix as the reference column for translating the signal perpendicular to the timeline. Furthermore, the interference distribution area is accurately extracted and filtered out according to the morphological processing. Finally, the simulation results prove that the proposed algorithms have an advantage over non-uniform interrupted-sampling repeater jamming in terms of interference suppression.
Data Augmentation Based on Contrastive Learning in Audio Anomaly Detection
Authors: Li Jiajia
Published: December 2022

Based on the contrastive supervised learning algorithm, this paper studies the impact of the linear combination of data augmentation in audio anomaly detection. Previous studies have shown that the linear combination of data enhancement performs well in image detection. However, there are few studies on similar methods in sound anomaly detection, and this study makes up for this gap. We apply transformations to one branch of the algorithm with the audio augmentation module of the AugLy library, and the other branch is directly transformed into the Mel spectrogram. We find that more data augmentation patterns can help neural networks learn more high-quality representations, and a suitable linear data combination augmentation can improve the performance of model generalization at a low cost. The combination effect of Add Background Noise + Pitch Shift is the best. The AUC index of the fan dataset is increased by 10.06% on average, and other datasets are also improved to varying degrees.
Gait Simulation Research of 2-DOF Lower Limb Rehabilitation Robot Based on ADAMS and MATLAB
Authors: Yang Yalong , Wang Jirong , Shi Lianwen , Li Jun
Published: December 2022

The two-degree-of-freedom (2-DOF) lower limb rehabilitation robot is developed to promote the functional recovery of hemiplegic patients. In order to improve the gait movement and shorten the development cycle, co-simulation technology is used to simulate and analyze the lower limb rehabilitation robot. ADAMS simulation software is used to model and analyze the dynamics of the robot and the MATLAB/Simulink module is used to build a PID control system to track the gait of the robot. In ADAMS dynamic simulation, the model walks according to the target trajectory, which verifies the correctness of the virtual prototype. In ADAMS and MATLAB co-simulation, the model follows the target trajectory to complete the gait. The trajectory tracking error was less than 1°.
Test-beam and simulation studies towards RPWELL-based DHCAL
Authors: Shaked-Renous D. , Amaro F.D. , Bhattacharya P. , Breskin A. , Chefdeville M. , Drancourt C. , Geralis T. , Karyotakis Y. , Moleri L. , Tesi A. , Titov M. , Veloso J. , Vouters G. , Bressler S.
Published: December 2022

Digital Hadronic Calorimeters (DHCAL) were suggested for future Colliders as part of the particle-flow concept. Though studied mainly with RPC, studies focusing on sampling elements based on Micro-Pattern Gaseous Detector have shown the potential advantages; they can be operated with environment-friendly gases and reach similar detection efficiency at lower average pad multiplicity. We summarize here the experimental test-beam results of a small-size DHCAL prototype, incorporating six Micromegas and two RPWELL sampling elements, interlaced with steel-absorber plates. It was investigated with 2–6 GeV pion beams at the CERN/PS beam facility. The data permitted validating a GEANT4 simulation framework of a DHCAL, and evaluating the expected pion energy resolution of a full-scale RPWELL-based calorimeter. The pion energy resolution derived for the RPWELL concept is competitive to that of glass RPC and Micromegas sampling techniques.
Effective Gain and Ion Back Flow study of triple and quadruple GEM detector
Authors: Greene Senta V. , Velkovska Julia , Blankenship Brandon , Reynolds Michael Z. , Tarafdar Sourav
Published: December 2022

Gas electron Multipliers (GEM) are a new generation of
gaseous avalanche devices in the Micro Pattern Gaseous Detector
(MPGD) category. GEMs are widely used in both nuclear and high
energy experiments as well as in medical science. Several parameters
define the performance of these types of devices under various
experimental conditions. This article focuses on the study of
effective gain and Ion Back Flow (IBF) in both triple and quadruple
GEM detectors. Effective gain and IBF are two of the most important
parameters in determining the performance of GEM detectors.
Exact calculation of the mean first-passage time of continuous-time random walks by nonhomogeneous Wiener–Hopf integral equations
Authors: Dahlenburg M , Pagnini G
Published: December 2022

We study the mean first-passage time (MFPT) for asymmetric continuous-time random walks in continuous-space characterised by waiting-times with finite mean and by jump-sizes with both finite mean and finite variance. In the asymptotic limit, this well-controlled process is governed by an advection-diffusion equation and the MFPT results to be finite when the advecting velocity is in the direction of the boundary. We derive a nonhomogeneous Wiener–Hopf integral equation that allows for the exact calculation of the MFPT by avoiding asymptotic limits and it emerges to depend on the whole distribution of the jump-sizes and on the mean-value only of the waiting-times, thus it holds for general non-Markovian random walks. Through the case study of a quite general family of asymmetric distributions of the jump-sizes that is exponential towards the boundary and arbitrary in the opposite direction, we show that the MFPT is indeed independent of the jump-sizes distribution in the opposite direction to the boundary. Moreover, we show also that there exists a length-scale, which depends only on the features of the distribution of jumps in the direction of the boundary, such that for starting points near the boundary the MFPT depends on the specific whole distribution of jump-sizes, in opposition to the universality emerging for starting points far-away from the boundary.
Physiological responses of several beef cattle breeds based on environmental conditions in Beef Cattle Research Station
Authors: Irmawanti S , Luthfi M , Prihandini P W
Published: December 2022

Physiological conditions were one factors that can affect the growth of cattle. The study aimed to determine the physiological responses of several beef cattle breeds that are reared in Beef Cattle Research Station (BCRS), Grati District, Pasuruan Regency, East Java Indonesia, was carried out by measure temperature, humidity, Temperature Humidity Index (THI), rectal temperature, respiration frequency, body temperature, Head Tolerance Coefficient (HTC) and heart rate of 159 cows consisting of Bali, Madura, Jabres, Galekan, Rambon, Peranakan Ongole (PO), Belgian Blue x PO cross, PO x Bali cross (POBA) which were observed during 4 months in pens. Data were analysed descriptively. The result of the study were ambient temperature and relative humidity of the pen ranged from 25-34.12°C and 54.88-84.27%, THI ranged from 74.92-84.97, body temperature ranged from 35.06-38.53°C, respiration frequency ranged from 20-54 times/minute, HTC ranged from 1.81-3.34, and heart rate ranged from 65-92 times/minute. It was concluded that several breeds of beef cattle in BCRS have mild to severe heat stress, high heat tolerance, respiration rate and heart rate. This condition does not cause production problem in several beef cattle, but in BB x PO cross it has potential to low productivity.
Is a State Bank A Useful Economic Development Tool in the USA?
Authors: Chirinko Robert S
Published: December 2022

The possibility of creating a state bank has received much recent attention in the USA. In 2021, six states introduced legislation to create a state bank; in 2019, similar legislation was enacted in California for municipal banks. This article develops a framework to evaluate state banking, reviews prior experiences with state banking and related alternatives to traditional private banking, and identifies five questions determining the advisability of creating a state bank. The overall goal is to shed some light on whether a state bank can be a useful tool to further state economic development and the welfare of state residents (JEL codes: G21 (banks), G28 (government policy, financial institutions), and H70 (state and local governments)).
The chromosome-scale genome of Kobresia myosuroides sheds light on karyotype evolution and recent diversification of a dominant herb group on the Qinghai-Tibet Plateau
Authors: Ning Yu , Li Yang , Dong Shu Bin , Yang Hong Guo , Li Chun Yi , Xiong Biao , Yang Jun , Hu Yu Kun , Mu Xian Yun , Xia Xiao Fei
Published: December 2022

Kobresia species are common in meadows on the Qinghai–Tibet Plateau. They are important food resources for local livestock, and serve a critical foundation for ecosystem integration. Genetic resources of Kobresia species are scarce. Here, we generated a chromosome-level genome assembly for K. myosuroides (Cyperaceae), using PacBio long-reads, Illumina short-reads, and Hi–C technology. The final assembly had a total size of 399.9 Mb with a contig N50 value of 11.9 Mb. The Hi–C result supported a 29 pseudomolecules model which was in consistent with cytological results. A total of 185.5 Mb (44.89% of the genome) transposable elements were detected, and 26,748 protein-coding genes were predicted. Comparative analysis revealed that Kobresia plants have experienced recent diversification events during the late Miocene to Pliocene. Karyotypes analysis indicated that the fission and fusion of chromosomes have been a major driver of speciation, which complied with the lack of whole-genome duplication (WGD) in K. myosuroides genome. Generally, this high-quality reference genome provides insights into the evolution of alpine sedges, and may be helpful to endemic forage improvement and alpine ecosystem preservation.
Karyotype evolution of the Asterids insights from the first genome sequences of the family Cornaceae
Authors: Dong Congcong , Wang Shang , Zhang Han , Liu Jianquan , Li Minjie
Published: December 2022

Cornaceae is a core representative family in Cornales, the earliest branching lineage in the Asterids on the life tree of angiosperms. This family includes the only genus Cornus, a group of ~55 species. These species occur widely in Northern Hemisphere and have been used as resources for horticultural ornaments, medicinal and industrial manufacturing. However, no any genome sequences are available for this family. Here, we reported a chromosome­level genome for Cornus controversa. This was generated using high-fidelity plus Hi–C sequencing, and totally ~771.80 Mb assembled sequences and 39,886 protein-coding genes were obtained. We provided evidence for a whole-genome duplication event (WGD) unique to C. controversa. The evolutionary features of this genome indicated that the expanded and unique genes might have contributed to response to stress, stimulus and defense. By using chromosome-level syntenic blocks shared between eight living genomes, we found high degrees of genomic diversification from the ancestral core-eudicot genome to the present-day genomes, suggesting an important role of WGD in genomic plasticity that leads to speciation and diversification. These results provide foundational insights on the evolutionary history of Cornaceae, as well as on the Asterids diversification.
Temporal resolution in transmission electron microscopy using a photoemission electron source
Authors: Kuwahara Makoto , Agemura Toshihide
Published: December 2022

Temporal resolution in transmission electron microscopy (TEM) has progressed to the sub-picosecond level with the stroboscopic method using a photoemission mechanism with an ultrafast laser for the electron gun. Time-resolved TEM in conjunction with a photocathode (PC)-type electron source pumped by a pulsed laser has been actively developed to exceed sub-nanosecond time resolution. Here, we provide an overview of the trends in this field and discuss the measurement targets that can be obtained by time-resolved measurements. Furthermore, we consider the types and characteristics of PC materials and their related physical quantities for evaluation of electron beam properties. Experimental results obtained by time-resolved TEM using a semiconductor PC that has a surface with a negative electron affinity are presented, and application results based on quantum mechanics are given. We also describe new techniques for improving the time resolution and new applications of pulsed electron beams in electron microscopy and discuss the measurement targets that are expected for time-resolved electron microscopy.
CONSTANS-LIKE 1a positively regulates salt and drought tolerance in soybean
Authors: Xu Chongjing , Shan Jinming , Liu Tianmeng , Wang Qi , Ji Yujia , Zhang Yuntong , Wang Mengyuan , Xia Ning , Zhao Lin
Published: December 2022

Salt and drought stresses are major factors limiting soybean (Glycine max [L.] Merr.) growth and development; thus, improving soybean stress tolerance is critical. In this study, both salt stress and drought stress induced mRNA levels of CONSTANS-like 1a (GmCOL1a) and stabilized the GmCOL1a protein. Transgenic 35S:GmCOL1a soybean plants exhibited enhanced salt and drought tolerance, with higher relative water content in leaves, greater proline content, lower malondialdehyde (MDA) content, and less reactive oxygen species (ROS) production compared with wild-type plants; the GmCOL1a knockout co-9 mutant showed opposite phenotypes. In addition, GmCOL1a promoted the expression of genes related to salt tolerance, effectively reducing the Na+/K+ ratio in soybean plants, especially in stems and leaves of 35S:GmCOL1a soybean. Chromatin immunoprecipitation sequencing (ChIP-seq) analysis identified two potential direct targets of GmCOL1a, late embryogenesis abundant (GmLEA) and Δ1-pyrroline-5-carboxylate synthetase (GmP5CS) genes, which were verified by chromatin immunoprecipitation quantitative polymerase chain reaction (ChIP-qPCR), electrophoretic mobility shift assay (EMSA), and transient transcriptional activation assays. GmCOL1a bound directly to the Myc(bHLH)-binding and Che-binding motifs of GmLEA and GmP5CS promoters to stimulate mRNA expression. Analysis of transgenic hairy-root GmP5CS:GmP5CS soybean plants in wild type, co-9, and 35S:GmCOL1a backgrounds further revealed that GmCOL1a enhances salt and drought tolerance by promoting GmP5CS protein accumulation in transgenic soybean hairy roots. Therefore, we demonstrate that GmCOL1a plays an important role in tolerance to abiotic stress in soybean.
Topological states in one-dimensional 𝒫𝒯-symmetric non-Hermitian spin-orbit-coupled Su–Schrieffer–Heeger lattices
Authors: Li Jia-Rui , Wang Zi-An , Xu Tong-Tong , Zhang Lian-Lian , Gong Wei-Jiang
Published: December 2022

Energy and topological-state properties of the one-dimensional non-Hermitian spin-orbit-coupled Su–Schrieffer–Heeger lattice are theoretically investigated by introducing spin-dependent onsite imaginary potentials with gain and loss. It is found that imaginary potentials lead to the appearance of imaginary energies in the topologically nontrivial phase region, and ${\cal {PT}}$ phase transition occurs in the topologically trivial region. In addition, the imaginary potentials and spin–orbit coupling act together to make the topological phase transition occur in the topologically trivial region, and the topologically nontrivial region becomes wider. The energy spectrum results show that imaginary potentials and spin–orbit coupling have obvious effects on the zero-energy edge states of this system, which mainly lie in the presence of four types of zero-energy states with different localization and numbers. Furthermore, we discuss diagonal disorder and the transport behavior of system, further characterizing the properties of the individual topological states. The above results indicate the special adjustment effect of imaginary potentials and spin–orbit coupling on the band structure of such a system.