Mechanics and Advanced Technologies最新文献

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Features of using the over-skiving method for multi-pass cutting of external gears 使用过削法进行外齿轮多道切削的特点
Mechanics and Advanced Technologies Pub Date : 2023-12-22 DOI: 10.20535/2521-1943.2023.7.3.289230
Ihor Hrytsai, A. Slipchuk
{"title":"Features of using the over-skiving method for multi-pass cutting of external gears","authors":"Ihor Hrytsai, A. Slipchuk","doi":"10.20535/2521-1943.2023.7.3.289230","DOIUrl":"https://doi.org/10.20535/2521-1943.2023.7.3.289230","url":null,"abstract":"Problem. There is a problem of determining the working parameters, including axial feed and cutting speed, as well as the helix angle of the teeth of the disc cutter and the tool spindle, the geometry of the cutting part, and the cutting depth per pass in Power skiving technology.Objective. It is necessary to investigate the cutting process using the Power Skiving method for generating external gears over multiple passes and develop recommendations for selecting its optimal parameters.Implementation methodology. The cutting force and its tangential component acting on the cutter are presented based on the fundamental principles of cutting theory, using the function of the cross-sectional area of the cut, the material strength limits of the workpiece for shear, and the intensity of plastic deformation of the chip. Calculations of the cut area are based on a graphoanalytical 3D model of the undeformed chip. The coefficient of shear intensity is determined depending on the thickness of the cut layers using the Deform 2D system. The study of the force factors is conducted in the initial stage for single-tooth cutting, considering the operation of a single tooth of the tool, and for multi-tooth cutting conditions, corresponding to real cutting and forming conditions in this method.Results. Analysis of harmonic vibrations with different frequencies of the investigated forces indicates that, under average loading, the maximum principal component of the cutting force occurs on the third pass, and the tangential force on the tool axis occurs on the first pass. The variation in the frequency of these signals is explained by changes in the contact angle between the tool and the gear wheel in the machine engagement and the different number of teeth involved in cutting.Conclusions. The obtained data allowed the development of a methodology for selecting rational parameters - axial feed values, the number of passes with different cutting depths to minimize time consumption, and achieve the desired accuracy of gears. It has been demonstrated that to reduce processing errors, it is most rational to decrease cutting force by increasing the number of passes, rather than reducing the axial feed.","PeriodicalId":32423,"journal":{"name":"Mechanics and Advanced Technologies","volume":"2 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139163466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Alternative technologies of composite of highly loaded aircraft structures: a qualitative method for making multicriteria decisions: Part III. Research of the methodological basis in decision-making: technological constructions in in the assessment toolki 高负载飞机结构复合材料的替代技术:多标准决策的定性方法:第 III 部分.决策方法论基础研究:评估工具中的技术构造
Mechanics and Advanced Technologies Pub Date : 2023-12-22 DOI: 10.20535/2521-1943.2023.7.3.293231
Volodymyr Zabashta
{"title":"Alternative technologies of composite of highly loaded aircraft structures: a qualitative method for making multicriteria decisions: Part III. Research of the methodological basis in decision-making: technological constructions in in the assessment toolki","authors":"Volodymyr Zabashta","doi":"10.20535/2521-1943.2023.7.3.293231","DOIUrl":"https://doi.org/10.20535/2521-1943.2023.7.3.293231","url":null,"abstract":"The third part of the article proceeds from the starting points in the decision-making problem (DMP) specified in the first stages of research [1, 2]. Here, we continue to compare the predominance (first of all, quality) of autoclave and non-autoclave alternative technological processes (ATP) as part of the stages of TP(e) with a linear algorithm of end-to-end action in the manufacture of carbon fiber (CF) aircraft structures (AC) such as highly loaded wing stringer panels (HLS) of B787, A350, MC-21, CSeries mainline aircraft as a component of hierarchical systems. To describe and study them, the following were involved: initial technological and verbal models, technological and mathematical model of an autonomous dynamic system (ADS) and a number of two-dimensional manifolds (topology) to it in the form of technological and geometric models. The article continues the study of development in this direction by approximating manifolds by polyhedra. Including co-cellular and double-formed structures - pentagonal pyramids and bipyramids, as well as bodies of revolution around them - cone and bicon. Examples of schematic and technological interpretive modeling are presented. The methodological basis is the main provisions of decision-making theory, factor analysis and system-process approach with the involvement of practice results (expert analysis), first of all, the definition of technological factors of processes with criterion assessments of the advantages, components of alternatives in their competitive strategies.","PeriodicalId":32423,"journal":{"name":"Mechanics and Advanced Technologies","volume":"134 19","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139164076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Directed circulating flows in tanks of moving objects 移动物体水槽中的定向循环流动
Mechanics and Advanced Technologies Pub Date : 2023-12-22 DOI: 10.20535/2521-1943.2023.7.3.291259
V. Kovalev
{"title":"Directed circulating flows in tanks of moving objects","authors":"V. Kovalev","doi":"10.20535/2521-1943.2023.7.3.291259","DOIUrl":"https://doi.org/10.20535/2521-1943.2023.7.3.291259","url":null,"abstract":"The results of liquid fuel inertial flows numerical modeling in the tanks of the spacecraft during its maneuvering in the Earth's orbit are given. It is shown that the circulations that occur when internal guiding devices are used in the form of widely spaced rigid baffles can be deformed and affect the flow space not covered by them. In addition, the circular moments of inertia of the liquid on the baffles can be controlled by means of the appropriate location of the guide devices in terms of width and distance from the tank wall. The force effects calculation of the moving fluid on the walls and internal structures makes it possible to fairly correctly present the hydrodynamic picture of the of inertial flows development, as well as predict the methods and means of compensation for such disturbances. According to the obtained results of the specified processes simulation in the tanks, it can be stated that the inertial flows of the liquid in the tanks are strongly nonlinear, the properties of which depend on the geometry, the initial conditions for the generation of peak force effects tank on the tank walls and bottoms. The use of internal guiding devices in the flow significantly changes the geometry of wave formations, corrects the coordinates and duration of resonant currents in the tank. The main task is to minimize the mass and dimensions of the baffles with a simultaneous increase in the damping efficiency of resonant flows. In addition, the determination of the power parameters real distribution contributes to the development of the latest, more effective designs of baffles, which will allow more reliable influence on uncontrolled inertial flows in tanks.","PeriodicalId":32423,"journal":{"name":"Mechanics and Advanced Technologies","volume":"21 9","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139165154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Effective decoupling method for derivation of eigenfunctions for closed cylindrical shell 推导闭合圆柱壳特征函数的有效解耦方法
Mechanics and Advanced Technologies Pub Date : 2023-12-22 DOI: 10.20535/2521-1943.2023.7.3.282190
Hlib Yudin, Igor Orynyak
{"title":"Effective decoupling method for derivation of eigenfunctions for closed cylindrical shell","authors":"Hlib Yudin, Igor Orynyak","doi":"10.20535/2521-1943.2023.7.3.282190","DOIUrl":"https://doi.org/10.20535/2521-1943.2023.7.3.282190","url":null,"abstract":"By expansion into Fourier series along the circumferential coordinate, the problem for elastic thin-walled closed cylindrical shell is reduced to 8th order differential equation with respect to axial coordinate. In spite that the general structure of eigenvalues for this equation was known starting from 60-s of last century, they were derived only to some simplified versions of the shell theory. So, the main goal of paper consists in development of the general procedure for determination of the eigenvalues. The idea is based on that the theory of shell is actually formed by two much simple problems: the plane task of elasticity and the plate problem, each of them is reduced to much easily treated biquadratic equation. So, we start from either of two problems (main problem) while not taking into account the impact from another (auxiliary) problem. After computing its eigenfunctions, we gradually introduce the influence of auxiliary problem by presenting its functions as linear combination of functions for main problem. The results of calculation show the perfect accuracy of the method for any desired number of significant digits in eigenvalues. The comparison with known results for concentrated radial force shows the perfect ability to solve any boundary problem with any desirable accuracy.","PeriodicalId":32423,"journal":{"name":"Mechanics and Advanced Technologies","volume":"129 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139164056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Comparison of critical plane models for multiaxial fatigue life prediction 用于多轴疲劳寿命预测的临界面模型比较
Mechanics and Advanced Technologies Pub Date : 2023-12-22 DOI: 10.20535/2521-1943.2023.7.3.287522
Yevhenii Savchuk, S. Shukayev
{"title":"Comparison of critical plane models for multiaxial fatigue life prediction","authors":"Yevhenii Savchuk, S. Shukayev","doi":"10.20535/2521-1943.2023.7.3.287522","DOIUrl":"https://doi.org/10.20535/2521-1943.2023.7.3.287522","url":null,"abstract":"Background. The operation of numerous machines and units takes place under conditions of multi-axial cyclic loading, which, as a rule, is non-proportional. Evaluating the fatigue durability of metal alloys under conditions of multi-axial non-proportional loading is a relevant task in modern engineering. Solving this problem requires fatigue calculation methods that would consider operating conditions and properties of structural materials, including factors such as the type of stress state, loading trajectory, material sensitivity to non-proportional loading, and so on.Objective. To conduct a comparative analysis of a range of fatigue life models based on the concept of the critical plane, including the Fatemi-Socie, Wang-Brown, Smith-Watson-Topper, Liu I, and Liu II approaches, and to identify the limits and peculiarities of their application.Methods. The fatigue lives calculated using the selected models were compared with experimental results obtained for various metal alloys subjected to uniaxial tension-compression, alternating torsion, and proportional and non-proportional multiaxial loading.Results. The applicability limits of fatigue life models based on the critical plane concept were analyzed for different metal alloys under conditions of proportional and non-proportional multiaxial loading.Conclusions. The research results demonstrated that models requiring the use of material constants obtained from tests in both tension-compression and alternating torsion provide reliable fatigue life estimates for various types of metal alloys. Calculations based solely on fatigue curves from alternating torsion better correlate with the results of tests on ductile materials, while calculations based on criteria utilizing fatigue curves from tension-compression align more closely with results from tests on brittle materials.","PeriodicalId":32423,"journal":{"name":"Mechanics and Advanced Technologies","volume":"62 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139164263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Investigation of the strength of a tank container during road transport 公路运输过程中罐式集装箱强度调查
Mechanics and Advanced Technologies Pub Date : 2023-10-16 DOI: 10.20535/2521-1943.2023.7.2.277820
Alyona Lovska
{"title":"Investigation of the strength of a tank container during road transport","authors":"Alyona Lovska","doi":"10.20535/2521-1943.2023.7.2.277820","DOIUrl":"https://doi.org/10.20535/2521-1943.2023.7.2.277820","url":null,"abstract":"Background. Increasing the efficiency of the transport industry leads to the need to introduce modern means of transport with improved technical, economic and environmental characteristics. At present, transportation of liquid cargoes, including those in international traffic, is carried out mainly in tank containers. Therefore, in order to increase the efficiency of tank containers operation it is important to introduce designs with improved performance. Objective. Highlighting the results of improvements to the tank-container design and a study of its strength in road transport. Methods. In order to reduce the material intensity of the tank container, it is proposed to use pipes of circular cross section as frame elements and to create a boiler of composite material. Determination of pipe design parameters has been carried out by optimisation calculations according to material intensity minimum criterion. In order to define strength properties of improved tank-container design the calculation by finite element method has been made which has been implemented by SolidWorks Simulation software. Results. On the basis of the made calculations it is established that at lifting of the container for top corner fittings the maximum equivalent pressure arising in vertical racks of a skeleton are equal 133,6 MPa, and in a boiler – 121,5 MPa, that is below allowed. Under conditions of tank-container transportation by motor transport the maximum stresses in its structure are fixed at influence on it of acceleration 1,2g in a longitudinal direction on a course of movement. The maximum equivalent stresses in the frame were 202.4 MPa, and in the boiler – 122.2 MPa, i.e. do not exceed permissible values. Conclusions. The research carried out will contribute to the development of the design of modern tank container designs and improve the operational efficiency of the transport industry.","PeriodicalId":32423,"journal":{"name":"Mechanics and Advanced Technologies","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139318438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Application of the geometric component of a product digital twin when studying its actual geometric parameters 在研究产品实际几何参数时应用产品数字孪生的几何组件
Mechanics and Advanced Technologies Pub Date : 2023-10-16 DOI: 10.20535/2521-1943.2023.7.2.288545
Sergey Kozlov, Volodymyr Vanin
{"title":"Application of the geometric component of a product digital twin when studying its actual geometric parameters","authors":"Sergey Kozlov, Volodymyr Vanin","doi":"10.20535/2521-1943.2023.7.2.288545","DOIUrl":"https://doi.org/10.20535/2521-1943.2023.7.2.288545","url":null,"abstract":"The article analyzes the results of using the digital twin concept to study changes in the geometric parameters (GP) of an aircraft wing during its production. The concept of creating a product digital twin is put into practice by constructing geometric models of the wing console at each key stage of its manufacture. The main attention is focused on studying the change in the GP of the caisson part of the wing console at the following stages: assembling of consoles in an aircraft fixture, assembling of consoles out of an aircraft fixture and final assembling of an aircraft. It is concluded that the first significant changes in wing GP appear at the stage of removing the wing caisson from the aircraft fixture. It is shown that even with acceptable mold forming characteristics of the aircraft fixture, it does not ensure compliance of the actual wing GP with the design data within the permitted tolerances and cannot be a means of controlling GP. It is substantiated the necessity of implementing into a wing caisson manufacturing technological process a procedure for monitoring the geometric shape of the unit after its removal from an aircraft fixture. It is proposed for a comprehensive assessment of isolated units’ geometric parameters to use a digital model of the aircraft, which is formed at each stage of the product manufacturing based on executed models of the units’ actual surfaces.","PeriodicalId":32423,"journal":{"name":"Mechanics and Advanced Technologies","volume":"76 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139318669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Damage of materials under proportional loading 材料在比例荷载下的损坏
Mechanics and Advanced Technologies Pub Date : 2023-10-16 DOI: 10.20535/2521-1943.2023.7.2.261955
Anatoly Grabovskiy, O. Bondarets, I. Babiienko
{"title":"Damage of materials under proportional loading","authors":"Anatoly Grabovskiy, O. Bondarets, I. Babiienko","doi":"10.20535/2521-1943.2023.7.2.261955","DOIUrl":"https://doi.org/10.20535/2521-1943.2023.7.2.261955","url":null,"abstract":"The work is devoted to the study of material damage during elasto-plastic proportional loading, in particular, the influence of two loading mechanisms, detachment and shear, is taken into account. These mechanisms include viscous, brittle, and visco-brittle modes of failure. The accumulation of scattered damage is considered as a multi-scale and multi-stage phenomenon that occurs during proportional loading at the micro- and meso-levels of the destruction of the metal structural material. As part of the study, a quantitative assessment of the degradation of the physical and mechanical properties of materials was performed, in particular, changes in the modulus of elasticity E and G, and the definition of equivalent damage arising from an elastoplastic proportional load is proposed. Experimental data on the kinetics of damage accumulation on 12X18N10T steel samples, which were subjected to axial load (tension), shear (torsion) and proportional load with the stiffness parameter of the stress state K = 0.5 before failure, are considered. The work compares experimental results with theoretical data, damage accumulation. The obtained conclusions contribute to a deeper understanding of the mechanisms of destruction of materials under the action of a proportional load, and can also find practical application in the design and assessment of the load-bearing capacity of structural elements.","PeriodicalId":32423,"journal":{"name":"Mechanics and Advanced Technologies","volume":"69 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139318432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Determination of the KIC Fracture Toughness of the X210Cr12 High-Strength Material 测定 X210Cr12 高强度材料的 KIC 断裂韧性
Mechanics and Advanced Technologies Pub Date : 2023-10-16 DOI: 10.20535/2521-1943.2023.7.2.282705
Ergun Ateş
{"title":"Determination of the KIC Fracture Toughness of the X210Cr12 High-Strength Material","authors":"Ergun Ateş","doi":"10.20535/2521-1943.2023.7.2.282705","DOIUrl":"https://doi.org/10.20535/2521-1943.2023.7.2.282705","url":null,"abstract":"Purpose: It is an important problem that the machines become unusable due to the deformation of the machine elements produced before the planned time. In this study, it was aimed to determine the KIC value of X210Cr12, which is a high strength material. In this way, more accurate load values can be used in the design.Methods: In the experimental study to determine the KIC value, the sample geometry, the crack depth, the load-dependent parameters and calculations and some conformity checks were carried out. Experimental system; KIC consists of 3-point flexure specimens, a press, an electronic circuit capable of detecting the change in load crack opening, and a logger.Findings: In the study, the loads were determined from experimental graphs. Subsequently, load-crack opening values were determined. With these data, the KIC values were calculated as 719,7 and 839,7 MPa.mm1/2 as the minumum and maximum values, respectively.Conclusion: The experimental graphs are in the form of curves that break abruptly with unstable crack propagation without showing plastic deformation. There is no study in the literature on the KIC value of X210Cr12 and it has been determined that it has a low KIC value compared to the high-strength steels studied. It is valuable to determine the KIC value, as fracture problems may occur in designs prepared with the material. The results of the study are data at room temperature.","PeriodicalId":32423,"journal":{"name":"Mechanics and Advanced Technologies","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139318499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Comparative analysis of hot reverse extrusion of hollow products from round and square blanks 圆形和方形坯料热反向挤压空心产品的比较分析
Mechanics and Advanced Technologies Pub Date : 2023-10-16 DOI: 10.20535/2521-1943.2023.7.2.288484
Volodumur Kaliuzhnyi, Stanislav Sytnyk, Volodymyr Levchenko
{"title":"Comparative analysis of hot reverse extrusion of hollow products from round and square blanks","authors":"Volodumur Kaliuzhnyi, Stanislav Sytnyk, Volodymyr Levchenko","doi":"10.20535/2521-1943.2023.7.2.288484","DOIUrl":"https://doi.org/10.20535/2521-1943.2023.7.2.288484","url":null,"abstract":"Background. Modern production of hollow products by hot reverse extrusion poses the task of reducing energy consumption and reducing metal costs for the manufacture of such products. Such problems can be solved by using them for extruding square-shaped blanks. Goal. Determination using the finite element method (FEM) of the parameters of hot reverse extrusion of hollow products from round and square blanks and comparison of the results of theoretical studies. Methodology of implementation. Theoretical studies of force modes of extrusion, specific forces and stress-strain state of metal were carried out by simulation using MSE in the DEFORM software environment. The results. Modeling of the process of hot reverse extrusion from low-carbon steel of a hollow product with protrusions on the end of the bottom part was carried out with the help of MSE. Round and square blanks are used. Extrusion forces, forces for removing punches from deformed blanks and forces for pushing out products from matrices are established. The distribution of specific forces on the deforming tool is revealed. The stress-strain state and temperature distribution in the deformed metal at the end of extrusion were determined. Evaluation of the working of the metal structure by hot plastic deformation was carried out and the obtained parameters were compared. Conclusions. The use of square-shaped blanks during hot reverse extrusion of hollow products is substantiated.","PeriodicalId":32423,"journal":{"name":"Mechanics and Advanced Technologies","volume":"124 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139318312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
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