Density Distribution Characteristics Research Articles

Investigation of current density and temperature distribution characteristics under transient conditions based on a 108 cm2 segmented proton exchange membrane fuel cell

Visualizing the electrochemical and temperature distribution characteristics inside proton exchange membrane fuel cell (PEMFC) should greatly contribute to the product development and performance optimization. In the study, a customized 27-segment 108 cm2 fuel cell was fabricated based on the printed circuit board methodology to achieve the local current density and local voltage measurement. In addition, 27 thermocouples were embedded in the segmented cathode graphite gas flow plate for local temperature measurement. Detailed information of fuel cell core components, multi-channel data acquisition system, external temperature control system, and uncertainty analysis was presented. According to the test results of 4000 s current rising conditions and 2400 s current decreasing conditions, the measurement deviation of total current between data acquisition system and TOYO test station is 2.4%–3.2%. Meanwhile, the deviation of output voltage ranges from 0.1% to 2.6%. To quantify the degree of distribution non-uniformity, the range and standard deviation of local parameter values as well as contour map are demonstrated. The non-uniformity of local current density and local temperature becomes more significant under higher operating current conditions. Furthermore, the degree of parameter non-uniformity is more noticeable under current rising conditions compared with current decreasing conditions. The transient increase of operating current leads to the sudden overshoot phenomena of local current range, and the change of local current density among all segments is instantaneously finished. However, the range of current demonstrates relatively smooth transition trends when reactant flow rate rises. Higher temperature area appears in the middle of membrane electrode assembly, especially in the position with higher local current density. The parameter distribution and transition characteristics could provide helpful guidance for fuel cell optimization and diagnosis.

Wind-induced interference effect of complex building clusters on long-span roof structures

The presence of complex buildings introduces interference effects and complicates the wind field around the long-span roof structure. The complexity of the problem makes it challenging to predict wind load of long-span roof structures, resulting in a scarcity of design data available to engineers and designers. Thus, the influence of interference effect on mean and peak pressure coefficients of a long-span tri-centered cylindrical roof structure was investigated through wind tunnel tests conducted in an atmospheric boundary layer wind tunnel. The study focused on the interference effects caused by two cooling towers, chimney, and some low-rise buildings, considering all wind directions. The results show that the interference effects are the result of a combination of amplification effects from the adjacent cooling towers and chimney and shielding effects from the surrounding low-rise buildings. Due to the shielding effect of low-rise buildings, the wind suction on the roof is mitigated compared to that of a single building, while at the end of the roof, wind suction is amplified by cooling tower effects. The interference effect of the building clusters, however, amplifies the fluctuating wind pressure coefficient and the peak pressure coefficient on the roof. To accurately estimate the wind load of building components and envelopes, furthermore, this study investigates the influence mechanism of interference effect on non-Gaussian characteristics of wind pressure combining with fluctuating wind pressure spectrum, spatial correlation of fluctuating wind pressure, and probability distribution characteristics of standardized wind pressure coefficient. The spatial correlation of wind pressure in the roof interference area exhibits a strong association, and the probability density distribution characteristics of the standardized wind pressure coefficient significantly deviate from the Gaussian curve, with a peak factor exceeding 3.5. Thus, it can be concluded that the wind pressure within this region demonstrates significant non-Gaussian characteristics. Hence, the zone values of peak pressure coefficients are determined using the peak factor approach to inform the wind resistance design of the envelope structure.

Design and characteristic analysis of flame cutting nozzles for ultralarge-thickness steel ingots

The cutting thickness of the flame cutting nozzle mainly depends on the characteristics of the cutting oxygen jet, and in the process of designing and manufacturing a flame cutting nozzle with an ultralarge thickness, it is impossible to carry out multiple experiments to optimize the design due to the difficulty in testing, safety, manufacturing cost, environmental pollution, and other problems. In this paper, the Laval-type cutting oxygen orifice channel was first designed by theoretical calculation, the pressure, velocity, Mach number, and density distribution characteristics of the cutting oxygen jet were investigated by numerical simulation, and the reliability and adaptability of the numerical simulation results were verified by experiments. Then, the numerical simulation comparison and estimation method of jet characteristics with the general-purpose G301-7# nozzle was used to study the cutting oxygen orifice channel of the ultralarge thickness flame cutting nozzle. The results show that under the condition of a 19 mm throat diameter and 10 atm inlet pressure, it was estimated that the length of cutting oxygen flow from the design nozzle can reach 1800 mm and the cutting thickness can reach 2500 mm based on the density value; the length of cutting oxygen flow can reach 2000 mm and the cutting thickness can reach 3800 mm based on the velocity value; the length of cutting oxygen flow can reach 1600 mm according to the value of the oxygen quality fraction; and the cutting thickness can reach 2800 mm based on the oxygen mass fraction content. Finally, trial production of the nozzle design, verification of the cutting test, the nozzle with a cutting thickness of 2500 mm at an oxygen pressure of 7 atm, and the cutting quality were all good.

Spatial Distribution Characteristics and Influencing Factors of Geographical Indication Agricultural Products in Shaanxi Province

Geographical indication agricultural products are of great significance to promote the high-quality development of rural revitalization due to their unique quality and brand value. Based on the geographical concentration index, the nearest neighbor index and the kernel density estimation method, this paper empirically studies the spatial distribution characteristics and influencing factors of 117 geographical indication agricultural products in Shaanxi Province. The results show that the spatial distribution of geographical indications in Shaanxi is extremely uneven, showing the characteristics of ' dense in the south and sparse in the north, regional agglomeration '. From the perspective of density distribution characteristics, the overall spatial distribution of geographical indications in Shaanxi shows a distribution pattern of ' three high and three times ', and the three high-density areas show a agglomeration distribution pattern of ' pin-shaped '. The difference between the north and the south is obvious, and the overall distribution pattern is ' cold in the north and hot in the south '. The spatial distribution pattern of geographical indications in Shaanxi is affected by many factors. Natural factors are the basis, social and economic factors strengthen the spatial distribution pattern of geographical indications, and government-led and policy factors play a regulatory and guiding role. It is suggested to optimize the spatial distribution pattern of geographical indications in Shaanxi, rely on local social resources, give full play to the leading role of the government, and actively promote the industrialization development of geographical indication products.

Optimal design and performance analysis of anode flow channels in proton exchange membrane water electrolyzers

In proton exchange membrane water electrolysis, the water/oxygen distribution characteristics in the anode channel significantly affect the electrolyzer performance. In this paper, a three-dimensional two-phase non-isothermal numerical model of the electrolyzer is established, in which the reaction kinetics equation is modified theoretically and is validated experimentally. Two novel anode channel structures (Straight-through turbulent flow channel and Mesh-like structured flow channel) are designed and their multiphysical field distribution characteristics are compared with the traditional straight-through flow channel. Results show that, for Straight-through flow channel structure, the liquid water saturation and temperature gradient between the under-channel and under-rib areas are large, resulting in bubble accumulation under the ribs, deterioration of heat and mass transfer, and harming the electrolyzer reaction rate. The two novel structures both have velocity component perpendicular to the channel flow direction, promoting the expulsion of oxygen accumulated in the anode porous electrode, contributing to more uniform distribution characteristics of gas-liquid two-phase flow and current density. At 2.5 V, the current density of Straight-through flow channel, Straight-through turbulent flow channel, and Mesh-like structured flow channel are 4.12, 4.14, and 4.53 A/cm2, respectively. The excellent heat and mass transfer characteristics enable the Mesh-like structured flow channel to have the best electrochemical performance.

A novel algorithm for estimating phytoplankton algal density in inland eutrophic lakes based on Sentinel-3 OLCI images

As one of the optically active components, phytoplankton are common photosynthetic organisms in oceans, nearshore, and inland water bodies. The variations in phytoplankton algal density play a crucial role in understanding primary productivity, carbon cycling, and early warning of algal blooms. In this study, three typical eutrophic lakes in China, Lake Taihu, Lake Chaohu, and Lake Dianchi, were taken as the research area. Algorithms for estimating algal density of cyanobacteria-dominated and non-cyanobacteria-dominated water types were developed based on Mie theory. The results demonstrated that the developedalgorithm had favorable estimation performance for inland eutrophic lakes, with a determination coefficient (R2) of 0.88, a mean absolute percentage error (MAPE) of 51%, an unbiased mean absolute percentage error (UMAPE) of 39%, and a root mean square error (RMSE) of 23.99 × 106 cells/L. Furthermore, comparison with other algorithms for estimating algal density showed that the developed algorithm had the lowest MAPE of 60% and UMAPE of 43%, with the RMSE of 23.42 × 106cells/L. Extensive evaluation based on satellite-ground synchronous data demonstrated the applicability of the developed algorithm to the Sentinel-3 OLCI sensor, enabling the determination of spatial and temporal distribution characteristics of algal density in the three lakes from 2016 to 2022 using Sentinel-3 OLCI images. The results of algal density inversion revealed a continuous decreasing trend in algal density in Lake Dianchi from 2016 to 2022, while the algal density in Lake Taihu and Lake Chaohu both decreased after 2019.

The effect of silica nanoparticles on the shock adiabatic relation and tensile strength in polyurethane

This work exploded the effect of silica nanoparticles on shock adiabatic relation and tensile fracture in polyurethane based on atomistic simulations. It is found that the non-uniform interface structures introduced by nanoparticles can increase the shock impedance, which also leading to increased twisting of polyurethane chains and the generation of local hotspots near the nanoparticles. The interface structures near the nanoparticle consists of polyurethane chains with a high gyration radius, and the average gyration radius increases approximately linearly with the increase in nanoparticle content. At lower shock velocity, the potential energy increment initially increases and then decreases with the increase in nanoparticle content. Bond analysis reveal that flexible segments dominate the bending and twisting deformations of polyurethane, while nanoparticles enhance the corresponding deformation degrees. Furthermore, nanoparticles can serve as void nucleation sites for early-stage tensile damage, resulting in a decrease in fracture strength. Differing from metals, the relationship between tensile strength and fracture temperature follows a more linear law. Nanoparticles inhibit the later growth and coalescence of voids by increasing the temperature and steric hindrance. The density and size distribution characteristics of voids are consistent with the changes in potential energy during the shock compression process. Unlike classical spallation, the curled polyurethane chains in the tensile region gradually orient along the shock direction, evolving into a void-fiber structure.

Effect of fluidized bed shapes on gas-solid fluidization characters and flow regime transition

The technology of gas-solid dense-phase fluidized bed separation is applied in the separation of fine particles in minerals due to its stable and reliable characteristics. The experiment collected time-domain distribution signals of pressure drop from fluidized beds with different shapes, systematically analyzed the spatiotemporal distribution characteristics of bed density, and studied the effects of bed shape and fluidization number N on the fluidization and flow transition of the bed layer. The results indicate significant differences in Umf among fluidized beds with different shapes, and the tapered bed requires the highest energy for fluidization. When N=1.3, the cylindrical bed layer is the most stable, maintaining an average density of 1.8 g/cm3, with a density fluctuation variance of 0.02 g/cm3. Additionally, when N<1.0, almost no bubbles inside the bed layer. With an increase in gas velocity, the time-domain distribution of pressure drop signals shows different degrees of fluctuation. When N=1.1, Conspicuous non-uniform particle flow is evident in the tapered bed, with a bubble main frequency of 8 Hz, an amplitude of 27.1, and the highest pressure drop energy signal, indicating that the tapered bed enters the bubbling state prematurely. Finally, fine coal separation experiments were conducted, and the results showed that the minimum E value for the cylindrical bed is 0.08 g/cm3, while the maximum E value for the tapered bed is 0.17 g/cm3.

Effects of community structure of Cunninghamia lanceolata sprouting forests with different densities on ecosystem carbon density at the early stage of succession.

To explore potential responses of ecosystem carbon density to changes of community structure during natural regeneration of woody plants, we analyzed the relationships between ecosystem carbon density and its components, tree species diversity, structural diversity (CVDBH) and spatial structure parameters (mingling, aggregation, dominance, crowding) of Cunninghamia lanceolata forests with different sprouting densities (1154, 847 and 465 individuals·hm-2) at the early stage of succession in Baishanzu National Park. The results showed that tree species diversity (species richness index and Shannon diversity index) increased with the decrease of sprouting density of C. lanceolata. Among the stand structural parameters, CVDBH, stand density, and mingling increased with the decrease of sprouting density of C. lanceolata. The stand distribution pattern of different C. lanceolata densities was uniform, with sub-dominant stand growth status and relatively dense status. The carbon density of tree layer under high, medium, and low sprouting densities of C. lanceolata were 57.56, 56.12 and 46.54 t·hm-2, soil carbon density were 104.35, 122.71 and 142.00 t·hm-2, and the total carbon density of ecosystem were 164.59, 182.41 and 190.13 t·hm-2, respectively. There was little variation in carbon density of understory layer and litter layer among different treatments. The carbon density distribution characteristics of different C. lanceolata densities were following the order of soil layer (63.4%-74.7%) > tree layer (24.5%-35.0%) > understory layer and litter layer (0.8%-2.0%). The results of variance partitioning analysis indicated that the change of tree layer carbon density was mainly influenced by stand structure diversity, soil layer carbon density was influenced by both tree species diversity and stand structure diversity, while ecosystem carbon density was mainly influenced by tree species diversity. Stand spatial structure parameters had a relatively little effect on ecosystem carbon density and its components. The sprouting density of C. lanceolata significantly affected ecosystem carbon accumulation during the conversion from C. lanceolata plantations to natural forests. A lower remaining density of C. lanceolata (about 500 individuals·hm-2) was more conducive to forest carbon sequestration.

Study on density distribution characteristics and fine coal separation of magnetically fluidized beds of microfine particles

ABSTRACT In this paper, the characteristics of the axial and the radial density distribution and the density stability of a gas-solid fluidized bed formed by microfine magnetite powder were studied under different fluidizing gas velocities and magnetic field intensities, and the separation experiments of −6 mm fine coal were carried out. The experimental results show that the axial density of the bed with magnetic field applied is lower than that without magnetic field applied under different gas velocities. The density fluctuation of the gas-solid fluidized bed with magnetic field is smaller than that of the ordinary gas-solid fluidized bed, and the stability of the bed density decreases with the increase of the fluidization number. The experimental results of separation of −6 mm fine coal show that the Ep value increases with the increase of fluidization number. Under the same fluidization number, the Ep value of −6 + 3 mm coal is smaller than that of −3 + 0.5 mm coal. When the fluidization number is 1.1, the Ep value of −6 + 3 mm coal is 0.0375 g/cm3, and the Ep value of −3 + 0.5 mm coal is 0.0475 g/cm3. This shows that the magnetically fluidized bed of microfine particles has a good separation effect for −6 mm coal.

Analysis of Atomic Thermal Vibration of CrN Based on Rietveld Refinement Method

The crystal structure of chromium nitride (CrN) is studied by X‐Ray diffraction from 25 to 600 °C. Based on the RIETAN‐2000 program of Rietveld refinement method, the experimental results are analyzed, and the crystal structure parameters of CrN powder crystals at different temperatures are refined. Atomic thermal vibration isotropic temperature factor B is directly obtained by the Rietveld refinement method. Using the maximum entropy method analytical procedure, the 3D and planar isoheight nuclear density distribution characteristics of CrN are derived, realizing the visualization of nuclear density distribution. It can help to calculate the thermal diffuse scattering.

Effects of temperature and cathode humidity on performance of PEM full cell

The performance of proton exchange membrane fuel cells (PEMFCs) is significantly influenced by their temperature and cathode humidity, as they affect power density and internal water distribution. The interdependent nature of these two parameters necessitates their simultaneous consideration in practical engineering to achieve high efficiency and reliable PEMFC operation. Therefore, this study proposes a synergistic analysis of the dual-parameter effect of working temperature and cathode humidity on PEMFC performance, using a three-dimensional steady-state model for counter-flow single-channel PEMFCs. The model's correctness is verified through comparison with experimental results, and the resulting power density and internal water distribution characteristics of PEMFCs are studied based on voltage changes. The findings indicate that the sensitivity of the proton exchange membrane (PEM) to temperature and cathode humidity varies at different voltage stages. Coupling analysis of these two factors enhances proton exchange membrane conductivity and expands the range of power density adjustment. Consequently, this study provides crucial insights into the interplay between temperature and cathode humidity in PEMFCs, facilitating the design and optimization of PEMFC systems for practical engineering applications.

B/PS bulges and barlenses from a kinematic viewpoint – I

ABSTRACT A significant part of barred disc galaxies exhibits boxy/peanut-shaped structures (B/PS bulges) at high inclinations. Another structure also associated with the bar is a barlens, often observed in galaxies in a position close to face-on. At this viewing angle, special kinematic tests are required to detect a 3D extension of the bars in the vertical direction (B/PS bulges). We use four pure N-body models of galaxies with B/PS bulges, which have different bar morphology from bars with barlenses to the so-called face-on peanut bars. We analyse the kinematics of our models to establish how the structural features of B/PS bulges manifest themselves in the kinematics for galaxies at intermediate inclinations and whether these features are related to the barlenses. We apply the dissection of the bar into different orbital groups to determine which of them are responsible for the features of the LOSVD (line-of-sight velocity distribution), i.e. for the deep minima of the h4 parameter along the major axis of the bar. As a result, we claim that for our models at the face-on position, the kinematic signatures of a ‘peanut’ indeed track the vertical density distribution features. We conclude that orbits responsible for such kinematic signatures differ from model to model. We pay special attention to the barlens model. We show that orbits assembled into barlens are not responsible for the kinematic signatures of B/PS bulges. The results presented in this work are applicable to the interpretation of IFU observations of real galaxies.

Study on forecasting model of transmission line failure rate and outage time

Given the complex problem of transmission line failure and outage and the difficulty of predicting the failure rate and outage time of the transmission line with certainty, the accident prediction information is provided for power grid managers. This paper proposes a three-order fundamental Fourier function fault rate prediction model based on a monthly time scale. This method does not rely on any strict assumptions and is driven by the real transmission line fault data in a province. The fitting results reflect the monthly bimodal fault characteristic distribution law of the transmission line fault rate. On this basis, the historical outage time is analyzed and counted, the probability density distribution characteristics of forced outage time are proposed, and the ExpGro function is used to fit it. The results show that the prediction results of the model proposed in this paper have good sharpness and reliability, which has a guiding significance for actual maintenance work.

Numerical Investigation of Electro-Thermal Field Distribution Law of Busbar under Different Operating Conditions

The electro-thermal state of a busbar system of electrolysis cells for aluminum production represents the main factor affecting hydromagnetic stability and current distribution. Based on the busbar system of a 500 kA aluminum electrolytic cell, an overall busbar electro-thermal field coupling calculation model was established based on ANSYS. The characteristics of busbar temperature, current density, and voltage drop distribution were analyzed. In addition, the electro-thermal distribution of the busbar system was simulated under different current intensities, ambient temperatures, and heat transfer coefficients. The results show that the temperature distribution of the riser busbar and the cathode busbar is higher in the middle location and tends to decrease along the two sides. Differences in heat conduction and heat dissipation environment are the main factors affecting the distribution of the busbar system’s electro-thermal field, while the Joule heat of the current is not the major factor. Increasing the current intensity will increase the average temperature and average voltage drop of the busbar. With an increase in the ambient temperature, the average busbar temperature increases significantly, and the voltage drop of the busbar also increases. With an increase in heat transfer coefficient, the average temperature and voltage drop of the busbar decreases.

Validation of FY-4A Temperature Profiles by Radiosonde Observations in Taklimakan Desert in China

The atmospheric temperature profiles (ATPs) retrieved through the geostationary Interferometric Infrared Sounder (GIIRS) onboard the FY-4A satellite (GIIRS/FY-4A) can effectively fill the gap of the scarce conventional sounding data in the Taklimakan Desert (TD), the second largest desert in the world, with an area of 330,000 square kilometers. In this study, we take the experimental radiosonde observations (RAOB) from one RAOB station in the hinterland of TD and seven conventional radiosondes in the oasis region around the desert as the true values and analyze the bias distribution characteristics of GIIRS/FY-4A ATPs with quality control (QC) flags 0 or 1 for this region. In addition, a bias comparison is made with GIIRS/FY-4A ATPs, and the fifth generation ECMWF atmospheric reanalysis of the global climate (ERA5) ATPs. The results show that (1) Missing measurements in GIIRS/FY-4A ATPs are the most frequent in the near-surface layer, accounting for more than 80% of all the retrieved grid points. The averaged total proportion of GIIRS/FY-4A ATPs with QC marks 0 or 1 is about 33.06%. (2) The root mean square error (RMSE) of GIIRS/FY-4A ATPs is less than 3 K, smaller than that of ERA5 ATPs. The RMSE of ERA5 ATPs can exceed 10 K in the desert hinterland. The absolute mean biases of GIIRS/FY-4A ATPs and ERA5 ATPs are, respectively, smaller than 3 K and 2 K, the former being slightly larger. The correlation coefficients of GIIRS/FY-4A ATPs with ERA5 ATPs and RAOB ATPs are higher than 0.98 and 0.99, respectively, and the correlation between GIIRS/FY-4A ATPs and RAOB ATPs is inferior to the latter. (3) The overall atmospheric temperature retrieved by GIIRS/FY-4A is 0.08 K higher than the temperature of RAOB, on average, while the overall temperature from ERA5 is 0.13 K lower than that of RAOB, indicating that the temperature profile obtained by integrating GIIRS/FY-4A ATPs and ERA5 ATPs may be much closer to RAOB ATPs. (4) The probability density of the GIIRS/FY-4A ATP biases in the TD region generally follows the Gaussian distribution so that it can be effectively assimilated in the 3-D variational assimilation modules. The probability density distribution characteristics of the GIIRS/FY-4A ATP biases in the desert hinterland and oasis are not much different. However, due to the fusion analysis of the relatively rich multi-source conventional observation data from the oasis stations, the probability density of ERA5 ATPs biases at the oasis stations is nearer to Gaussian distribution than that of the GIIRS/FY-4A ATPs. In the desert hinterland, where conventional observation is not enough, the probability density distributions of the ATPs biases from ERA5 and GIIRS/FY-4A are alike. Therefore, the GIIRS FY4A can contribute to a more accurate estimation of ERA5 ATPs in the TD region.

Density distribution characteristics of the explosively formed reactive material jet

The density evolution behaviour and distribution characteristics of the explosively formed reactive material jet were studied based on the SPH algorithm. Numerical simulations show that the reactive material jet has obvious expansion phenomenon under the shaped charge effect. Especially, the expansion and divergence of the jet head are obvious. In general, the density deficit occurs in the whole reactive material jet, and the density increases from the jet head to the tail. Compared with the initial density of the reactive liner material, the density of jet head decreases by about 30%. In addition, the effect laws of the reactive liner thickness, the liner cone angle, and the type of explosive on the jet density distribution were investigated. With increasing of the reactive liner thickness, increasing of the liner cone angle, and decreasing of the explosive detonation pressure, the proportion of the high-density area on the reactive jet and the average density of the jet head increase.

Influence of interface roughness and rock type on mixed mode fracture characteristics of tunnel shotcrete-rock interface

A four-point shear (FPS) test was conducted to investigate the mixed mode fracture characteristics of the shotcrete-rock interface. Real-time monitoring of the fracture process was achieved using acoustic emission (AE) and digital image correlation (DIC) techniques. The mechanical test results indicate that residual stress increases with modal Angle or roughness under the same crack mouth opening displacement (CMOD). As the modal angle increases, the crack morphology and damage mechanism of the granite-shotcrete interface change. For large modal angles, the crack expands into the granite during the expansion process, leading to a larger range of granite damage at the interface. The results obtained through the nearest neighbor method reveal that specimens with small mode angle, low roughness or weak material properties on one side do not exhibit obvious background events, whereas the cluster characteristics of density distribution are evident. The AE events with smaller nearest neighbor distances were found to be concentrated around the macroscopic cracks. Moreover, the modal angle was observed to have a significant impact on crack opening/sliding displacement, with crack mouth sliding displacement (CMSD) and crack tip sliding displacement (CTSD) both increasing significantly as the modal angle increases.

Ultrasound‐trigged micro/nanorobots for biomedical applications (2/2023)

Ultrasound (US)-propelled micro- and nanorobots (MNRs) have shown their bright future in multidisciplinary fields. This review presents several advanced and repre-sentative US-propelled MNRs with inhomogeneous density distribution, asymmet-ric shape, hollow cavity, and other features.

Multi-featured multi-scale combination of high-resolution remote sensing images for building extraction

Abstract As one of the important feature categories in urban geographic data, buildings are the key thematic elements to be represented in large-scale urban mapping with the high speed of urban digital construction. The identification and extraction of buildings are of great significance for feature extraction, feature matching, image interpretation and mapping. However, the great variability of building size, shape, color, orientation, etc., in remote sensing images poses a great challenge to building detection. To this end, this paper proposes an algorithm based on multi-feature multi-scale fusion for the automatic extraction of buildings in remote sensing images are represented in the form of roofs. It is difficult to represent all buildings with a single feature because of the different colors, textures and shapes of building roofs. Effective features to describe buildings are proposed, including edge density and edge distribution, brightness contrast, color contrast and other features to describe building edge brightness. We propose effective features to describe buildings, including edge density and edge distribution, luminance contrast, color contrast and other underlying features to describe the edges, luminance and color of buildings, and adding special structural features such as main direction orthogonality and target integrity and symmetry to describe buildings by multiple features together. Moreover, the K-value nearest neighbor classification algorithm is used to train a series of samples, and the weights of each feature in the multi-feature model are obtained through iterative learning to obtain the multi-feature linear model and calculate the visual saliency of buildings in the sliding window; finally, the proposed algorithm has experimented with several groups of high-resolution remote sensing images respectively, and the multi-scale multi-feature fusion model algorithm is used as the Erkoff random field model to compare the algorithm. The results of this paper show that the proposed multiscale multi-feature fusion model algorithm improves by 10.82% for building classification accuracy extraction and 13.96% for feature selection extraction accuracy, and finally, the comparison from the shape optimization effect figure concludes that the multiscale multi-feature fusion model can achieve better extraction accuracy and practical effect for buildings in remote sensing images, which has certain practicality and It has certain practicality and superiority. It promotes the in-depth application of multi-feature multi-scale combined high-resolution remote sensing image-building extraction in geographic states, road traffic and other industries.t