Pub Date : 2023-12-18DOI: 10.20998/2079-0775.2023.2.10
M. Tkachuk, Sergiy Nazarenko, A. Grabovskiy, M. Tkachuk, O. Shut, Andrii Lipeiko, Volodymyr Veiler, Oleksiі Marusenko, Mykola Prokopenko, S. Marusenko, Anton Vasiliev, I. Hrechka, I. Khramtsova
A lot of problems arise when tank engines are equipped with high-speed elements. They are related to the need of analyzing the stress-strain state and critical modes of rotation of these elements. For that reason, it requires an in-depth analysis of requirements and constructive solutions of engines and their high-speed elements. Moreover, modern studies of engine dynamics attract attention. Attention should also be paid to the analysis of existing designs of turbocharging systems of tank engines. It is important to analyze the models and research methods of the static and dynamic stress-strain state of turbocharger impellers as well. The analysis of problem aspects has been carried out and it is possible to note that for now the problem of studying the stress-strain state and critical modes of rotation of high-speed elements of tanks and engines for armored vehicles does not have a complete solution. We need new approaches, models and research methods and tools that create a basis for substantiating progressive technical solutions. Keywords: armored vehicles; tank engines; turbocharger; high-speed elements; stress-strain state
{"title":"ANALYSIS OF DESIGNS, MODELS AND METHODS OF STUDYING THE DYNAMICS OF HIGH-ROTATION ELEMENTS OF TANK ENGINES (REVIEW ARTICLE)","authors":"M. Tkachuk, Sergiy Nazarenko, A. Grabovskiy, M. Tkachuk, O. Shut, Andrii Lipeiko, Volodymyr Veiler, Oleksiі Marusenko, Mykola Prokopenko, S. Marusenko, Anton Vasiliev, I. Hrechka, I. Khramtsova","doi":"10.20998/2079-0775.2023.2.10","DOIUrl":"https://doi.org/10.20998/2079-0775.2023.2.10","url":null,"abstract":"A lot of problems arise when tank engines are equipped with high-speed elements. They are related to the need of analyzing the stress-strain state and critical modes of rotation of these elements. For that reason, it requires an in-depth analysis of requirements and constructive solutions of engines and their high-speed elements. Moreover, modern studies of engine dynamics attract attention. Attention should also be paid to the analysis of existing designs of turbocharging systems of tank engines. It is important to analyze the models and research methods of the static and dynamic stress-strain state of turbocharger impellers as well. The analysis of problem aspects has been carried out and it is possible to note that for now the problem of studying the stress-strain state and critical modes of rotation of high-speed elements of tanks and engines for armored vehicles does not have a complete solution. We need new approaches, models and research methods and tools that create a basis for substantiating progressive technical solutions. Keywords: armored vehicles; tank engines; turbocharger; high-speed elements; stress-strain state","PeriodicalId":505484,"journal":{"name":"Bulletin of the National Technical University «KhPI» Series: Engineering and CAD","volume":"122 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139174680","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}
Pub Date : 2023-12-18DOI: 10.20998/2079-0775.2023.2.09
Volodymyr Sierykov
The work is devoted to the review of modern trends in the research and use of planetary gearboxes of armored vehicles. An analysis of the areas of application of mechanical transmissions was carried out. The advantages and disadvantages of using gear gearboxes as part of mechanical transmissions are described. The design features of the use of gears in transmissions are considered. The requirements for gear gearboxes as part of transmissions are defined. The advantages and disadvantages of using planetary gearboxes and their areas of use are analyzed. The classification of mechanical adjustable gears according to general features, as well as individual ones, is considered. An overview of the fulfillment of the conditions for increasing reliability was carried out, taking into account the design features of stepped gearboxes, which are divided into three groups: simple gearboxes (with fixed shaft axes); planetary gearboxes (with movable shaft axes); combined (combination of a simple and planetary gearbox in one unit). A brief review of modern approaches to planetary gear box modeling, taking into account inertial, elastic, dissipative, transformer and frictional properties, taking into account other characteristic features of the planetary series, is carried out. An analysis of known ways of solving problems of such modeling was carried out. Modern methods of calculating the strength of planetary gearboxes, including those with partial destruction, and corresponding software complexes are analyzed. The need for the development of more advanced mathematical models that adequately describe the stress-strain state in gear engagements has been identified. Keywords: design, planetary gearboxes, mechanical transmission, influence of operating factors, diagnostic parameters, synthesis of kinematic schemes
{"title":"ANALYSIS OF RESEARCH ON PLANETARY GEARBOXES OF ARMORED VEHICLES (REVIEW ARTICLE)","authors":"Volodymyr Sierykov","doi":"10.20998/2079-0775.2023.2.09","DOIUrl":"https://doi.org/10.20998/2079-0775.2023.2.09","url":null,"abstract":"The work is devoted to the review of modern trends in the research and use of planetary gearboxes of armored vehicles. An analysis of the areas of application of mechanical transmissions was carried out. The advantages and disadvantages of using gear gearboxes as part of mechanical transmissions are described. The design features of the use of gears in transmissions are considered. The requirements for gear gearboxes as part of transmissions are defined. The advantages and disadvantages of using planetary gearboxes and their areas of use are analyzed. The classification of mechanical adjustable gears according to general features, as well as individual ones, is considered. An overview of the fulfillment of the conditions for increasing reliability was carried out, taking into account the design features of stepped gearboxes, which are divided into three groups: simple gearboxes (with fixed shaft axes); planetary gearboxes (with movable shaft axes); combined (combination of a simple and planetary gearbox in one unit). A brief review of modern approaches to planetary gear box modeling, taking into account inertial, elastic, dissipative, transformer and frictional properties, taking into account other characteristic features of the planetary series, is carried out. An analysis of known ways of solving problems of such modeling was carried out. Modern methods of calculating the strength of planetary gearboxes, including those with partial destruction, and corresponding software complexes are analyzed. The need for the development of more advanced mathematical models that adequately describe the stress-strain state in gear engagements has been identified. Keywords: design, planetary gearboxes, mechanical transmission, influence of operating factors, diagnostic parameters, synthesis of kinematic schemes","PeriodicalId":505484,"journal":{"name":"Bulletin of the National Technical University «KhPI» Series: Engineering and CAD","volume":"6 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139174754","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}
Pub Date : 2023-12-18DOI: 10.20998/2079-0775.2023.2.03
Vyacheslav N. Burlayenko, R. Kouhia, Svetlana Dimitrova
The finite element package Abaqus is used for modeling and analysis of free vibrations of axially functional graded beams with non-uniform cross-sections. Considerable attention has been paid to this aspect of the geometry, as it has a significant effect on the behavior of the beam as a structural component. User-defined material model subroutines (UMAT) were developed in a unified way for one- and three-dimensional models of the specified beams to provide numerical implementation of functional material gradients within each finite element. UMAT procedures were programmed in FORTRAN in the MS Visual Studio environment and compiled with the main program package using the Intel Fortran Compiler. In the procedures, material heterogeneity was assigned to each material integration point of appropriate standard one- and three-dimensional finite elements, eliminating the need to design graded finite elements via user-defined element subroutine. Frequencies and mode shapes of free vibrations of one- and three-dimensional axially functional graded beams with non-uniform cross-sections were found using the Lanczos method in Abaqus. An analysis of the accuracy and effectiveness of the proposed modeling approach was carried out, comparing the obtained results with data known in the literature. The presented modeling technique based on user-defined material subroutines provides valuable opportunities for scientists and engineers engaged in the dynamic analysis of structural components made of functionally gradient materials and having variable geometry along the axial direction. Keywords: axially functionally graded beams; non-uniform cross-section beams; free vibrations; graded finite element; Abaqus user defined subroutines
有限元软件包 Abaqus 用于对横截面不均匀的轴向功能分级梁的自由振动进行建模和分析。由于几何形状对梁作为结构组件的行为有重大影响，因此对这方面的问题给予了极大关注。针对指定梁的一维和三维模型，以统一的方式开发了用户自定义材料模型子程序（UMAT），以便在每个有限元中对功能材料梯度进行数值计算。UMAT 程序是在 MS Visual Studio 环境下用 FORTRAN 编写的，并使用英特尔 Fortran 编译器与主程序包一起编译。在程序中，材料异质性被分配到适当的标准一维和三维有限元的每个材料积分点，从而无需通过用户定义的元素子程序来设计梯度有限元。使用 Abaqus 中的 Lanczos 方法计算了具有非均匀横截面的一维和三维轴向功能分级梁的自由振动频率和模态振型。通过将获得的结果与文献中已知的数据进行比较，对所提出的建模方法的准确性和有效性进行了分析。所提出的基于用户定义材料子程序的建模技术为从事功能梯度材料结构组件动态分析的科学家和工程师提供了宝贵的机会，这些结构组件沿轴向具有可变的几何形状。关键词：轴向功能梯度梁；非均匀截面梁；自由振动；梯度有限元；Abaqus 用户自定义子程序
{"title":"FINITE ELEMENT MODELLING AND ANALYSIS OF FREE VIBRATIONS OF AXIALLY FUNCTIONALY GRADED BEAMS WITH NON-UNIFORM CROSS-SECTIONS","authors":"Vyacheslav N. Burlayenko, R. Kouhia, Svetlana Dimitrova","doi":"10.20998/2079-0775.2023.2.03","DOIUrl":"https://doi.org/10.20998/2079-0775.2023.2.03","url":null,"abstract":"The finite element package Abaqus is used for modeling and analysis of free vibrations of axially functional graded beams with non-uniform cross-sections. Considerable attention has been paid to this aspect of the geometry, as it has a significant effect on the behavior of the beam as a structural component. User-defined material model subroutines (UMAT) were developed in a unified way for one- and three-dimensional models of the specified beams to provide numerical implementation of functional material gradients within each finite element. UMAT procedures were programmed in FORTRAN in the MS Visual Studio environment and compiled with the main program package using the Intel Fortran Compiler. In the procedures, material heterogeneity was assigned to each material integration point of appropriate standard one- and three-dimensional finite elements, eliminating the need to design graded finite elements via user-defined element subroutine. Frequencies and mode shapes of free vibrations of one- and three-dimensional axially functional graded beams with non-uniform cross-sections were found using the Lanczos method in Abaqus. An analysis of the accuracy and effectiveness of the proposed modeling approach was carried out, comparing the obtained results with data known in the literature. The presented modeling technique based on user-defined material subroutines provides valuable opportunities for scientists and engineers engaged in the dynamic analysis of structural components made of functionally gradient materials and having variable geometry along the axial direction. Keywords: axially functionally graded beams; non-uniform cross-section beams; free vibrations; graded finite element; Abaqus user defined subroutines","PeriodicalId":505484,"journal":{"name":"Bulletin of the National Technical University «KhPI» Series: Engineering and CAD","volume":"159 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139173389","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}
Pub Date : 2023-12-18DOI: 10.20998/2079-0775.2023.2.08
Nickita Levin, Oleksandr Ustinenko, M. Bošanský, R. Protasov, O. Bondarenko, Sergij Andrienko
Reducing the mass and dimensions of gears is an actual task of modern mechanical engineering. One of the perspective ways to solve it is the use of gearing with a convex-concave contact of the teeth. The study is devoted to the development of mathematical model and algorithm for the optimal design of cylindrical gears with convex-concave contact of the working surfaces. Optimality criteria: minimum contact stresses taking into account design, geometrical and technological constraints. An objective function is constructed for the case of minimizing contact stresses: contact stresses σH in the mesh must take the minimum possible value when all constraints are met. Variables planning are defined. These are pressure angle at the pole αС, the curvature radius at the upper part of contact path rkh, and the curvature radius at the lower part of contact path rkd. A method for solving the problem of optimal design is chosen – probing the space of design parameters was chosen from all the variety. The points of the LPτ-sequence are used as test points. The algorithm for optimal design of gear has been developed. They take into account the constructive, technical and technological features. They also allow to reduce the error of the calculations due to the error-control of the calculations. The main stages of the algorithm are as follows: setting input data (numerical constraints on design variables, gear parameters and its load); generation of LPτ-sequence for variables planning with simultaneous consideration of their numerical constraints; checking of functional constraints; additional verification calculations (if necessary) of the gearing contact strength; formation of an array of possible solutions; searching of the best solution variant (the test point corresponding to the minimum value of the objective function) by sorting the array. Keywords: gear, convex-concave contact, optimization, objective function, variables planning, algorithm
{"title":"MATHEMATICAL MODEL AND OPTIMIZATION ALGORITHM ACCORDING TO THE CRITERIA OF MINIMUM CONTACT STRESS FOR GEARS WITH CONVEX-CONCAVE CONTACT","authors":"Nickita Levin, Oleksandr Ustinenko, M. Bošanský, R. Protasov, O. Bondarenko, Sergij Andrienko","doi":"10.20998/2079-0775.2023.2.08","DOIUrl":"https://doi.org/10.20998/2079-0775.2023.2.08","url":null,"abstract":"Reducing the mass and dimensions of gears is an actual task of modern mechanical engineering. One of the perspective ways to solve it is the use of gearing with a convex-concave contact of the teeth. The study is devoted to the development of mathematical model and algorithm for the optimal design of cylindrical gears with convex-concave contact of the working surfaces. Optimality criteria: minimum contact stresses taking into account design, geometrical and technological constraints. An objective function is constructed for the case of minimizing contact stresses: contact stresses σH in the mesh must take the minimum possible value when all constraints are met. Variables planning are defined. These are pressure angle at the pole αС, the curvature radius at the upper part of contact path rkh, and the curvature radius at the lower part of contact path rkd. A method for solving the problem of optimal design is chosen – probing the space of design parameters was chosen from all the variety. The points of the LPτ-sequence are used as test points. The algorithm for optimal design of gear has been developed. They take into account the constructive, technical and technological features. They also allow to reduce the error of the calculations due to the error-control of the calculations. The main stages of the algorithm are as follows: setting input data (numerical constraints on design variables, gear parameters and its load); generation of LPτ-sequence for variables planning with simultaneous consideration of their numerical constraints; checking of functional constraints; additional verification calculations (if necessary) of the gearing contact strength; formation of an array of possible solutions; searching of the best solution variant (the test point corresponding to the minimum value of the objective function) by sorting the array. Keywords: gear, convex-concave contact, optimization, objective function, variables planning, algorithm","PeriodicalId":505484,"journal":{"name":"Bulletin of the National Technical University «KhPI» Series: Engineering and CAD","volume":"16 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139175898","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}
Pub Date : 2023-12-18DOI: 10.20998/2079-0775.2023.2.05
Grigoriy Ivanets, S. Horielyshev, D. Baulin, Mihail Ivanets, Pavel Volkov
Modern war is a test of the material and spiritual forces of the people, the state and its Armed Forces, which prompts each country to maintain its defense capability at a level that guarantees reliable protection of society. Analysis of the nature of armed conflict in recent decades shows a sharp increase in the impact of modern weapons and military equipment on the course and outcome of military operations. Currently, weapons and military equipment form the basis of the combat power of the armed forces of any state and are the determining factor in achieving success in war or armed conflict. Despite the rapid development of anti-tank weapons and the decrease in survivability on the battlefield, main battle tanks remain one of the decisive means of modern combined arms combat, which is characterized by dynamism, saturation and speed. They provide the combat stability of their own forces in defense and advance during the offensive, destroy enemy armored vehicles, fire points and living forces. A comparative analysis of the main characteristics of modern combat tanks, the advantages and disadvantages of various types of vehicles of foreign and domestic production, used by the Armed Forces of Ukraine for the defense of the state and countering the aggression of Russia against Ukraine, in order to improve the effectiveness of their use in different conditions of combat. Western models of modern tanks and the Ukrainian tank "Oplot" in some significant combat characteristics prevail over the modern Russian tank T-90, in particular: in the power of the engine and its reliability of operation (engine overheating and failure); in the effectiveness of optoelectronic counteraction to optical enemy means; in the effectiveness of dynamic protection and countering modern weapons; in the perfection of the fire control system; in the sufficiency of the armor of the machine; in the effectiveness of actions in urban conditions. Keywords: war, battle tank, tactical and technical characteristics, effectiveness, comparative analysis
{"title":"COMPARATIVE ANALYSIS OF COMBAT CAPABILITIES OF MODERN TANKS OF VARIOUS TYPES","authors":"Grigoriy Ivanets, S. Horielyshev, D. Baulin, Mihail Ivanets, Pavel Volkov","doi":"10.20998/2079-0775.2023.2.05","DOIUrl":"https://doi.org/10.20998/2079-0775.2023.2.05","url":null,"abstract":"Modern war is a test of the material and spiritual forces of the people, the state and its Armed Forces, which prompts each country to maintain its defense capability at a level that guarantees reliable protection of society. Analysis of the nature of armed conflict in recent decades shows a sharp increase in the impact of modern weapons and military equipment on the course and outcome of military operations. Currently, weapons and military equipment form the basis of the combat power of the armed forces of any state and are the determining factor in achieving success in war or armed conflict. Despite the rapid development of anti-tank weapons and the decrease in survivability on the battlefield, main battle tanks remain one of the decisive means of modern combined arms combat, which is characterized by dynamism, saturation and speed. They provide the combat stability of their own forces in defense and advance during the offensive, destroy enemy armored vehicles, fire points and living forces. A comparative analysis of the main characteristics of modern combat tanks, the advantages and disadvantages of various types of vehicles of foreign and domestic production, used by the Armed Forces of Ukraine for the defense of the state and countering the aggression of Russia against Ukraine, in order to improve the effectiveness of their use in different conditions of combat. Western models of modern tanks and the Ukrainian tank \"Oplot\" in some significant combat characteristics prevail over the modern Russian tank T-90, in particular: in the power of the engine and its reliability of operation (engine overheating and failure); in the effectiveness of optoelectronic counteraction to optical enemy means; in the effectiveness of dynamic protection and countering modern weapons; in the perfection of the fire control system; in the sufficiency of the armor of the machine; in the effectiveness of actions in urban conditions. Keywords: war, battle tank, tactical and technical characteristics, effectiveness, comparative analysis","PeriodicalId":505484,"journal":{"name":"Bulletin of the National Technical University «KhPI» Series: Engineering and CAD","volume":"231 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139174207","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}
Pub Date : 2023-12-18DOI: 10.20998/2079-0775.2023.2.11
M. Tkachuk, M. Novikov, M. Tkachuk, A. Grabovskiy, Glib Pakki, Hanna Tkachuk, Serhii Podrieza, Roman Dereviankin
The paper describes an integrated approach to the design and technological support of enhanced performance of turbo-expander power plants. An analysis of the current state of development of turboexpander power plants has made it possible to establish that traditional approaches have largely exhausted the possibilities of improving their technical characteristics. Moreover, a situation is emerging where, in order to ensure the improvement of such characteristics, it is necessary to involve not isolated design or technological measures, but joint design and technological measures. To implement this approach, the method of generalized parametric modeling is used. At the same time, by combining design and technological parameters, the parametric space in which to search for rational technical solutions for turbo-expander power plants is expanded. This expansion of the parametric space makes it possible to increase the efficiency of the final solution. Such a solution cannot be achieved through design or technological measures alone. The developed approach is implemented in the form of a sequence of solved stages. First, it is a study of the working processes of gas dynamics, heat and mass transfer, and power generation in turboexpander power plants. Secondly, it is the optimization of technological operations for strengthening the elements of these plants. Thirdly, it is the development of real samples of turbo-expander power plants with improved technical characteristics. In general, these stages, which are carried out in a coordinated manner on the basis of the developed generalized parametric approach, made it possible to increase the durability of turboexpander elements by 25-40 % and ensure the efficiency of the detander at the level of 86 %. Keywords: turbo-expander power plant; turbine installation; discrete-continuous strengthening, generalized parameter, design and technological support; technical characteristics
{"title":"AREAS AND STAGES OF DESIGN AND TECHNOLOGICAL SUPPORT FOR ENHANCED PERFORMANCE OF TURBO-EXPANDER POWER PLANTS","authors":"M. Tkachuk, M. Novikov, M. Tkachuk, A. Grabovskiy, Glib Pakki, Hanna Tkachuk, Serhii Podrieza, Roman Dereviankin","doi":"10.20998/2079-0775.2023.2.11","DOIUrl":"https://doi.org/10.20998/2079-0775.2023.2.11","url":null,"abstract":"The paper describes an integrated approach to the design and technological support of enhanced performance of turbo-expander power plants. An analysis of the current state of development of turboexpander power plants has made it possible to establish that traditional approaches have largely exhausted the possibilities of improving their technical characteristics. Moreover, a situation is emerging where, in order to ensure the improvement of such characteristics, it is necessary to involve not isolated design or technological measures, but joint design and technological measures. To implement this approach, the method of generalized parametric modeling is used. At the same time, by combining design and technological parameters, the parametric space in which to search for rational technical solutions for turbo-expander power plants is expanded. This expansion of the parametric space makes it possible to increase the efficiency of the final solution. Such a solution cannot be achieved through design or technological measures alone. The developed approach is implemented in the form of a sequence of solved stages. First, it is a study of the working processes of gas dynamics, heat and mass transfer, and power generation in turboexpander power plants. Secondly, it is the optimization of technological operations for strengthening the elements of these plants. Thirdly, it is the development of real samples of turbo-expander power plants with improved technical characteristics. In general, these stages, which are carried out in a coordinated manner on the basis of the developed generalized parametric approach, made it possible to increase the durability of turboexpander elements by 25-40 % and ensure the efficiency of the detander at the level of 86 %. Keywords: turbo-expander power plant; turbine installation; discrete-continuous strengthening, generalized parameter, design and technological support; technical characteristics","PeriodicalId":505484,"journal":{"name":"Bulletin of the National Technical University «KhPI» Series: Engineering and CAD","volume":"155 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139174380","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}
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