Post-processing methods that rely on fusion-grided forecast products can reduce systematic biases from Numerical Weather Prediction (NWP) precipitation forecasts. However, these also limit the capability to accurately at local stations. We constructed a Station-based Precipitation Model (SPPM) utilizes deep-learning algorithms, predominantly convolutional layers and ResNet modules. Based 390 meteorological stations in North China European Centre for Medium-Range Forecasts Highest-resolution...

As the frozen soil in South Pole region of Moon is an important water resource, operation drilling and retrieving samples this will be a crucial task for us to accomplish future deep-space exploration. Thus, paper investigated effects increasing temperature heat transfer between tools simulated lunar minimize degradation during due increased temperature. Specifically, discrete element method was adopted parameters particles were calibrated based on equivalent particle system. Moreover,...

This paper presents a detailed thermal simulation analysis of the drilling process for icy soil in lunar polar region. The aim is to investigate temperature changes that occur debris removal area during process. We developed multi-level particle size model includes sieve based on geometric constraints evaluate influence specific heat capacity and conductivity temperature. Using central composite design method, we carried out test analyzed average difference particles within outside range...

This study is part of the preliminary research for Chang’e 7 project in China. The plans to drill penetrate lunar polar soil and collect samples using a spiral groove structure. Ice cold environment region one important targets sampling. In vacuum surface, icy are sensitive ambient temperature prone solid–gas phase change as increases. To predict range samples, this analyzed effect thermal parameters on rise particles discrete element simulation. included analysis conductivity specific heat...

Abstract Coaxial composite fibers with a cortex of polyacrylonitrile (PAN) and core layer mesophase pitch (MP) PAN were prepared by wet spinning, then heat‐treated in air. The effects heat treatment on the thermal reaction characteristics, pre‐oxidation degree, radial structure, stability coaxial studied differential scanning calorometry, Raman, thermogravimetric analysis. As temperature increases, only undergo cyclization without oxidation, peak increases from 258 to 270°C, enthalpy 19.66...

Water ice is an important water source in lunar polar soil. Drilling and sampling soil are engineering tasks of exploration. In view the influence temperature rise on quality samples obtained by drilling, heat transfer drilled ice-containing were investigated. this study, a thermal simulation model for drilling was established based discrete element method (DEM). Simulations containing at 3–5% performed assuming normal pressure low temperature. After validating feasibility accuracy method,...

Drilling samples of lunar soil is an important and indispensable part China’s exploration project. The drill bit temperature during the drilling process one key concerns for scholars, especially hard rock in vacuum. In this article, simulation analysis atmosphere vacuum conducted. Moreover, a fiber grating measuring system integrated with established. Experiment on stimulant taken out compared. DOI :  http://dx.doi.org/10.11591/telkomnika.v12i6.5496 Full Text: PDF

The study of direct push sampling characteristics forms the theoretical basis for deep tool design. In this paper, a ground test was carried out to analyze three influencing factors: tube diameter; friction coefficient; and soil plug length. Using discrete element method software, EDEM, lunar subsurface model established. We propose vortex structure particle displacement field in establish connection between factors disturbance plug. EDEM simulation revealed microscopic mechanism penetration...

Electric multiple unit is a modern transportation tool with high efficiency and large carrying capacity. Regarding its speed, reliability requirement of the train very important. As main load bearing component train, wheel subjected to harsh working condition. Rolling contact between rail leads fatigue failure so that becomes one most attractive fields in electric study. This article proposed assessment method. It could obtain critical parts’ stress distribution efficiently through...

At present, 80% of the information people receive every day comes from vision. The traditional direct contact measurement method cannot meet highly intelligent requirements in operation and manipulation. In current research, a novel measuring distance was proposed to simplify steps promote efficiency terms two-dimensional image recognition inverse perspective transformation. This new developed by primarily establishing prior knowledge base auto-correlation function MATLAB program Harris...

Discrete element method (DEM) is getting a wider use in granular media study. It fundamental of lunar soil DEM study that matching the micromechanical parameters simulant with its macro parameters. In this paper, work carried out by simulating triaxial test applying PFC3D software, and constitutive model parallel-bonded (PB) to match physical characteristics high-dense simulant. We first discuss influence different on peak strength soil. then role particle size simulation work, find key...

In the lunar rock drill mission, bit design is restricted by environment and system load.As executive unit of bit, cutter its material decides drilling system's penetration performance.In this paper, a new kind surface set PCBN developed, application advantage cubic boron nitride (CBN) on cutters discussed.The tested load experiments comparing with cemented carbide bit.

Abstract As an important index to quantitatively measure the motion performance of a manipulator, reliability is affected by many factors, such as joint clearance. The present research utilized UR10 manipulator object. A factor mapping model for influencing was established. link flexibility factor, clearance and Denavit–Hartenberg (DH) parameters were comprehensively considered in this model. coupling relationship among various factors concisely expressed. Subsequently, nonlinear response...

For a better original state and scientific value of lunar soil samples, research on the impact drill bits perturbation rate based DEM was carried out. A simulated model established linear adhesion contact model. The parameters were determined by matching between mechanics discrete elements. evaluation criteria states samples built basis actual project needs. Based this, some simulations for drilling sampling with different bit parameters, such as internal diameter, cutting angle height...

Purpose The purpose of this paper is to develop a novel method for analyzing wheel-rail (W-R) contact using thermo-mechanical measurements and study the effects heating on characteristics W-R under different creepages. Design/methodology/approach This developed an implicit-explicit finite element (FE) model which could solve both partial slip full sliding problems by setting angular velocities wheels. Based model, four material types six creepages were simulated. Findings results showed that...

Abstract To improve the kinematic performance of remote center mechanism for surgical robot, a double space index and accuracy reliability are proposed to optimize dimensional sizes mechanism. First, influence angular error on position operability in workspace analyzed. The weighted establish index. Second, is established based joint clearance output accuracy. Finally, adjustment parallelogram optimized optimization indices. Multipopulation genetic algorithm used obtain optimal size...

Abstract Critical size lunar soil particles refer to with a particle similar the diameter of drill bit, which is an important factor affecting drilling sampling, and its influence uncertain. In this paper, discrete element method used simulate sampling process critical size, position shape on load analysed. It found that have special migration trajectories characteristics during sampling. The are key factors load. This study can support design tools for exploration

Nanoscale zero-Valent Iron (nZVI) particles were prepared in the presence of 20 kHz ultrasonic irradiation order to enhance disparity and reactivity simultaneously avoid agglomeration. Dechlorination 3-chlorobiphenyl (3-Cl BP) by nZVI was investigated understand its feasibility for an situ remediation contaminated groundwater. Experimental results showed that induction ultrasound during preparation further enhanced removal efficiency 3-Cl BP, meanwhile Biphenyl (BP) formation rates increased...

Abstract A “X” type spring folding wing is taken as the research object in this paper, and schematic diagrams of unfolding locking process are drawn according to its structure working principle. The theoretical model kinematics dynamics which considering gravity moment established by simplifying geometric deployment mechanism wing, so curve angle angular velocity outer during can be obtained. pulley diameter, preload force stiffness spring-actuated random variables, time regarded evaluation...

As an important basis for determining the state of liver, mechanical responses are associated with many factors, and belong to a complex coupling system. Liver tissue has significantly complicated vascular channels. The diameter, deflection angle depth defined as key characteristic parameters. influences these parameters on were analyzed. On real parameters, coupled numerical model blood vessel, flow liver was established. corresponding obtained by utilizing different effects differences...