Metall i lit''e Ukrainy最新文献

{"title":"Dependence of hardness and other properties of gray iron on its carbon equivalent and degree of eutecticity","authors":"К. A. Sirenko, V. L. Mazur, D. О. Derecha","doi":"10.15407/steelcast2023.02.042","DOIUrl":"https://doi.org/10.15407/steelcast2023.02.042","url":null,"abstract":"The chemical composition, carbon equivalent and properties of castings from unalloyed and low-alloyed gray irons with lamellar graphite of various grades from СЧ100 to СЧА400 were analyzed in accordance with DSTU 8833:2019. There is a reference to such cast iron in the technical conditions for brake pads made of composite materials (rubber mixtures), in particular, for the production of cast iron inserts. Other products for railway transport are also made from cast iron СЧ350, for example, the friction “Khanin wedge”. It is shown that in industrial batches of the “Khanin wedge”, cast from cast iron СЧ350, the hardness did not correlate either with the content of elements in the chemical composition of the cast iron, or with the carbon equivalent due to the narrow range of its values even within the cast iron of the same grade. According to DSTU 8833:2019, with an increase in the carbon equivalent in the possible regulated range of values (%) from 3.03 to 4.54, the Brinell hardness of HB monotonically decreases by approximately 1.54...1.57, and the coefficient of thermal conductivity increases by almost one and a half times. Reducing the sulfur content in the chemical composition from 0.20 to 0.05 % of CH350 cast iron significantly reduces the range of dispersion of the carbon equivalent. The parameters (mean values, mean square deviations and coefficients of variation) of the carbon equivalent and the degree of eutecticity of the chemical composition of cast irons with lamellar graphite of brands from СЧ100 to СЧА400 were determined by means of statistical tests using the Monte Carlo method. It is shown that due to the significant dispersion of the values of the carbon equivalent of the chemical composition, hardness, coefficient of thermal conductivity, strength, density, modulus of elasticity, linear shrinkage, heat capacity, coefficient of linear expansion of cast iron with lamellar graphite of grades from СЧ100 to СЧА400 according to DSTU 8833:2019, it is necessary from the specified list grades of cast iron to determine and regulate in the technical conditions for composite brake pads a specific grade of cast iron intended for the manufacture of inserts in such pads.","PeriodicalId":33778,"journal":{"name":"Metall i lit''e Ukrainy","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135501011","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}

{"title":"Some specifics of the billet open and submerged stream casting","authors":"O.M. Smirnov, V.Ye. Ukhin, S.V. Semiriagin, A.Yu. Semenko, V.V. Osypenko, Yu.O. Smirnov, Yu.P. Skorobagatko, D.V. Ryabiy","doi":"10.15407/steelcast2023.02.034","DOIUrl":"https://doi.org/10.15407/steelcast2023.02.034","url":null,"abstract":"Experimental series of steel casting were carried out to determine the effect of the continuous casting method on the fre-quency of defects formation in billets. At the same time, the 125x125 mm square billets production was carried out on a six-strand caster with casting speeds of 2.8-4.3 m/min. In the process of research, a series of 5 melts of steel 60 (St60) was initially casted with an open stream. After that, using the same molds, 5 melts of steel 40X were sequentially casted with a submerged stream. As a result of an industrial experiment, it was found that because of the open stream continuous casting the number of rhomboidal billets was 4.5 %. In the case of using the submerged stream technology defects in the billet shape were not observed. The use of the \"stopper rod” — \"tundish nozzle\" — \"submerged entry nozzle\" system allows to control metal consumption during casting more accurate and timelier in automatic mode without changing the billet casting speed. At the same time, the position of the metal level in the mold is constantly ensured, which most accurately considers the features of the billet solid shell formation over the entire mold length at the current casting speed. The absence of the need to control the casting speed by the level of metal in the tundish makes it possible to maintain the optimal amount of melt in it, which sta-bilizes the casting temperature. The submerged casting prevents bubbling at the phase boundary in the mold and provides the possibility of a significant increase in the nozzle inner diameter (compared to the open stream) that reduces the rate of its clogging with corundum deposits several times. In addition, submerged casting allows the use of special mold powders, which improve the surface quality of the billets. It is possible to additionally improve billets quality using electromagnetic stirring of liquid steel during continuous casting.","PeriodicalId":33778,"journal":{"name":"Metall i lit''e Ukrainy","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134889821","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}

{"title":"The investigation of the thermal performance of the graphitized hollow electrode in the \"ladle-furnace\" with the supply of neutral gas","authors":"V. O. Ruban, O. M. Stoianov","doi":"10.15407/steelcast2023.02.018","DOIUrl":"https://doi.org/10.15407/steelcast2023.02.018","url":null,"abstract":"The article presents an analysis of heat transfer efficiency from an electric arc discharge formed in the sub-electrode zone to a metal bath under different operating conditions of the “ladle-furnace” (LF). A numerical modeling methodology has been developed, and the obtained data have been analyzed to determine the heat transfer efficiency with the supply of neutral gas through a graphitized hollow electrode (GHE). The objective of this study is the numerical modeling of the influence of changing the geometric parameters of the metal bath cavity formed by gas injection through the channel of the graphitized hollow electrode on the heat transfer efficiency from the electric arc to the metal bath at different thickness of the slag cover in the “ladle-furnace”. Research methods. Numerical modeling of the heating of the metal bath was performed on a developed 3D model of a steel ladle with liquid metal and a cavity zone formed under the action of an electric arc and gas supplied through the channel of the graphitized hollow electrode. Heating was conducted under different geometric parameters of the cavity and varying heights of the slag cover. The obtained data were analyzed, indicating the advantage of using the graphitized hollow electrode with gas supply through its channel compared to a conventional electrode. Results obtained. The share of heat absorbed by the slag and metal under the conditions of using a conventional electrode and a hollow electrode with gas supply through its channel was determined. The influence of the parameters of the reaction zone formed under the GHE on the heat transfer from the electric arc to the metal bath was determined, with maximum temperature increase values of the metal amounting to 0.6 ºC/min. Scientific novelty. New data were obtained regarding the influence of neutral gas supply through GHE on the amount of heat transferred to the metal by convection, and indicators of the heat flux density from the electric arc to the metal cavity in the sub-electrode zone were determined. Practical significance. It was determined that increasing the area of the metal cavity by supplying gas through the GHE channel improves the heat transfer from the electric arc to the metal bath. Meanwhile, increasing the thickness of the slag cover reduces heat losses to the furnace atmosphere. The carried out research provided important data regarding the thermal performance of the \"ladle-furnace\" in the sub-electrode zone, which can be further utilized for process optimization.","PeriodicalId":33778,"journal":{"name":"Metall i lit''e Ukrainy","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135500766","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}

{"title":"Effect of electromagnetic melt mixing on the technological process of aluminium powder production","authors":"S. L. Polyvoda, O. V. Siryi, O. M. Hordynia, V. O. Tverdokhvalov, O. V. Perekhoda","doi":"10.15407/steelcast2023.02.069","DOIUrl":"https://doi.org/10.15407/steelcast2023.02.069","url":null,"abstract":"Efficiency of including the operation of electromagnetic stirring is shown on example of aluminium powder production modernization. The existing technological scheme was characterized by inefficiency due to the need to pour the melt with a ladle from the rotary furnace to the resistance furnaces, increased electricity costs due to the need to overheat the entire bath of liquid metal to the injection temperature, and the difficulty of adjusting the temperature of the melt, which led to the metal crystallization in the nozzle or required its significant overheating above 900 ºС. Due to modernization, the intermediate resistance furnaces were replaced by a resistance furnace with a capacity of 1.5 tons, equipped with an electromagnetic stirrer of liquid metal. This led to an increase in the production productivity, decrease in energy costs and an increase in the level of automatization. Stirring system provides a non-contact influence on the liquid metal and allows to maintain the necessary temperature and hydrodynamic regimes of the melt in the crucible of the resistance furnace. To form a stirrer channel, a mixture based on vologran was used. It has high heat resistance, low density and thermal conductivity, high chemical resistance to liquid aluminium alloys and low tendency to oxides overgrowth. The use of melt electromagnetic stirring eliminated its overheating in crucible and stabilized the temperature near point of 790 ± 10 ºС. At the same time, the temperature of a metal in the injection zone was 840-850 ºС. Stabilizing the temperature regimes of melt injection made it possible to exclude its crystallization in the nozzle and increase its service life. Lowering the injection temperature by 50-60 ºC made it possible to reduce the oxidation of powder particles, which increased its quality. Modernization of production increased the production capacity of aluminium alloy powder from 300 to 500 kg/hour.","PeriodicalId":33778,"journal":{"name":"Metall i lit''e Ukrainy","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135501009","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}

{"title":"Creation of binders for casting cores from orthophosphoric acid and aluminosilicate fillers","authors":"R. V. Liutyi, A. S. Kocheshkov, О. М. Myslyvchenko, D. V. Liuta","doi":"10.15407/steelcast2023.02.073","DOIUrl":"https://doi.org/10.15407/steelcast2023.02.073","url":null,"abstract":"The article presents the results of the research of aluminophosphate binders, which were obtained as a result of the chemical interaction of orthophosphoric acid with dust-like aluminosilicates. The subjects of the research are the phase and chemical composition, the dynamics of thermal transformations of the binders, as well as the properties of core mixtures with them. In the experiments, it was established that due to the chemical interaction of dust-like pyrophyllite Al2(OH)2[Si4O10] or dystensillimanite Al2O[SiO4] with orthophosphoric acid after heating to 300 ºC, strong and thermally stable binders are formed, which are crystalline and amorphous aluminum orthophosphates. These phases provide strong bonding of the refractory filler and high strength of the core mixture. X-ray phase and differential thermogravimetric analyzes were used in the work to determine the structure and properties of binders. To determine the composition of the core mixture, the compositional planning of the experiment with appropriate data processing was applied. For the first time, the structure of aluminum phosphate binders, which were obtained from refractory fillers common in foundry production, was investigated. The conditions for the formation of crystalline phases were analyzed for the first time. It was established that as a result of the interaction of orthophosphoric acid with dysten-sillimanite, a larger specific amount of aluminum orthophosphate and a smaller amount of residual quartz is formed than when the acid interacts with pyrophyllite. This ensures a higher strength of the core mixture, for the formation of the binder in which orthophosphoric acid and dystensillimanite are used. Mass ratios are taken into account for the complete realization of the chemical reaction of the formation of the aluminum phosphate binder. The composition of a core mixture based on quartz sand with orthophosphoric acid and dysten-sillimanite was developed, which hardens after heating to 300 ºC and has a compressive strength of at least 2.0 MPa.","PeriodicalId":33778,"journal":{"name":"Metall i lit''e Ukrainy","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135501014","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}

{"title":"Especially deep desulphurization of cast iron by magnesium mono-injection in ladles of different size","authors":"A. P. Shevchenko, B. V. Dvoskin, I. O. Manachyn, V. G. Kislyakov, S. A. Shevchenko","doi":"10.15407/steelcast2023.02.027","DOIUrl":"https://doi.org/10.15407/steelcast2023.02.027","url":null,"abstract":"The article is devoted to the development and industrial mastering of technological processes of particularly deep desulphurization of cast iron (sulphur content ≤ 0.002 %) by magnesium mono-injection in ladles of various sizes. The paper presents the results of research on the development of technologies for extra deep desulphurization of cast iron by mono-injection of granular magnesium, which was carried out at modern automated cast iron desulphurization and slag rolling complexes. The work was carried out jointly by Ukrainian and Chinese specialists in China at Wuhan Steel Plant No. 1 using 110-ton ladles and in Taiwan at CSC Steel Plant No. 2 using 300-ton ladles. The proven technological parameters of the cast iron desulphurization processes using granular magnesium injection with tuyeres with evaporation chambers at Steel Plant No. 1 of Wuhan Steel and double-nozzle tuyeres at Steel Plant No. 2 of CSC Concern ensured the required processing cycles, reliable and technological magnesium injection and its absorption efficiency. It was found that the degree of desulphurization of cast iron is up to 99 % of treatments and the final sulphur content in cast iron is up to 0.0002 %, with the total estimated degree of magnesium absorption into sulphur, residual magnesium and deoxidation of cast iron being ~95 %. It has been established that an important technological technique that increases the stability of the achieved processing parameters is the adjustment of the ladle slag composition, which was carried out by adding waste granular lime in the amount of 1.0-2.0 kg/t of cast iron and did not require significant costs. The results of industrial cast iron treatments were analysed and nomograms of the dependence of specific magnesium consumption on the initial sulphur content for tuyeres of various designs were constructed. The developed processes are economically justified for use in the practice of preparing cast iron for conversion.","PeriodicalId":33778,"journal":{"name":"Metall i lit''e Ukrainy","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135500769","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}

{"title":"Assessment of changes in productivity and limitations in forcing movement when increasing the volume of blast furnaces","authors":"G. Yu. Kryachko, Ye. M. Sigarev","doi":"10.15407/steelcast2023.02.008","DOIUrl":"https://doi.org/10.15407/steelcast2023.02.008","url":null,"abstract":"The selection of the useful volume of new or reconstructed blast furnaces is an urgent task for both manufacturers and designers; therefore, the assessment of the technological capabilities of furnaces of different volumes has always been of interest from both a practical and a theoretical point of view. The purpose of the presented work is the selection of the most representative indicators, with the help of which a comparative assessment of the operation of furnaces of different volumes is possible, the evaluation of the operation of furnaces in the conditions of planned and market economies, as well as an attempt to determine and classify the factors limiting the forced operation of furnaces of increased volume. It is shown that the use of indicators calculated per unit area furnace is not appropriate, since area furnace is not the main size furnace. The main size is full volume furnace, which determines design unit and amount of capital costs for its construction. Specific productivity indicators calculated per unit volume furnace similarly depend on the height furnace and adequately reflect performance of furnaces of different volumes. The indisputable advantage of compact blast furnaces with a useful volume < 1500 m3 in comparison with furnaces of larger volumes is shown, which indicates imperfection of a simplified approach to evaluating performance of furnaces based on the concepts of balance and gas dynamic components, since it is difficult to take into account all the components when determining these components influencing factors. Factors limiting process intensification in blast furnaces of medium and large volumes have been established and classified. The main external factors are the quality characteristics of coke, iron ore materials and blowing, more specifically, hot strength of coke, richness of raw materials in iron and the ability of air blowers to provide blowing with required degree of compression. The main structural solutions to overcome significant limitations in operation of furnaces with a useful volume > 1500 m3 are a rational profile, ratio of output cross-section of air nozzles and cross-section furnace, as well as the use of coneless loading devices.","PeriodicalId":33778,"journal":{"name":"Metall i lit''e Ukrainy","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135501034","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}

{"title":"Trends of the foundry market of Ukraine in the first quarter of the XXI century","authors":"V. A. Gnatush, V. S. Doroshenko, S. I. Klymenko","doi":"10.15407/steelcast2023.02.083","DOIUrl":"https://doi.org/10.15407/steelcast2023.02.083","url":null,"abstract":"An analysis of the state of foundry production in Ukraine is presented. The foundry industry of Ukraine in the 21st century significantly reduced its production indicators, which is due to the influence of such factors as the stagnation of industries that consume metal castings, as well as a decrease in exports. This situation has been negatively affected by the COVID-19 pandemic, as well as the global foundry industry, due to a decrease in demand for castings from end manufacturers. It was predicted that positive developments should be expected in the near future. However, russia's attack on Ukraine on February 24, 2022 made a significant correction in the development of the global economy, and, accordingly, in the functioning of the world foundry industry. Ukrainian companies in the foundry industry felt the impact of the war, some of them suffered partial destruction of their production premises. Large foundry enterprises of Ukraine are mostly located in the south-eastern regions, which were the most affected by hostilities. At the same time, in order to reflect the real situation in the foundry industry of Ukraine, it is advisable to organize the collection of real data regarding the production of castings from various alloys in the country, as well as regarding the export and import of foundry products. This will make it possible to make effective decisions regarding the program of modernization of the industry and the development of industries that consume domestic metal castings. Ultimately, this will help increase the competitiveness of Ukrainian products and increase revenues to the budget of Ukraine. To assess the direction of development of foundry production in advanced countries of the world, the statistical data of the leading countries regarding the production of castings and in more detail such countries as Poland, Germany and the USA are given. The structure of cast products produced in the world is in constant dynamics and there is a constant change in the ratio of the volumes of castings produced from various alloys. Recent years have been characterized by a tendency to reduce the production of castings from steel and gray iron with a simultaneous increase in the share of castings from highstrength cast iron and aluminum alloys.","PeriodicalId":33778,"journal":{"name":"Metall i lit''e Ukrainy","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135501013","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}

{"title":"Influence of sintering conditions on the structure formation of tungsten-based composite materials","authors":"А. V. Minitskyi, M. M. Yamshinskij, Ye. H. Byba, N. V. Minitska, K. V. Polishchuk, I. V. Lukianenko, B. V. Kyvhylo","doi":"10.15407/steelcast2023.02.062","DOIUrl":"https://doi.org/10.15407/steelcast2023.02.062","url":null,"abstract":"The use of heavy tungsten alloys is essential for many industries, as these alloys are ideal for a variety of products due to their high density. The main problem in creating such alloys is the need to use high sintering temperatures, which significantly complicates the technology of producing tungsten alloys. To reduce the sintering temperatures of tungsten alloys, alloying elements are added to their composition to activate sintering processes at lower temperatures (nickel, iron and copper). The main task in forming the structure and properties of tungsten-based alloys is to ensure sintering conditions in the presence of the liquid phase, which contributes to the formation of a strong framework in the material structure and high density of the composite. Various methods of producing tungsten-based alloys have been investigated and the influence of the chemical composition of alloying additives on the sintering process conditions has been studied. The effect of pressing and post-pressing pressure on the porosity of tungsten-based molds was determined. It is shown that in the pressure range of 200-700 MPa, the maximum compaction of tungsten powder occurs at pressures of 500-550 MPa, which provides porosity at the level of 35-37 %. The difference between the sintering mechanisms of W-Ni and W-Fe systems at a temperature of 1350 ºC, which is sufficient for liquid-phase sintering with a nickel bond, and low for an iron bond, is shown. The process of infiltration of a porous tungsten alloy framework with copper melt obtained from metal-working waste was studied. The conditions that ensure complete impregnation of the tungsten framework with copper at a temperature of 1200 ºC and allow to obtain a porous material are determined. The results of the work can be used to create tungsten-based products with high specific gravity and density, including from metalworking waste, which significantly reduces the cost of such materials.","PeriodicalId":33778,"journal":{"name":"Metall i lit''e Ukrainy","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135501012","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}

{"title":"Modern approaches in the creation of high-entropy and medium-entropy cast aluminum alloys","authors":"I.F. Likhatskyi, М.М. Voron","doi":"10.15407/steelcast2022.03.102","DOIUrl":"https://doi.org/10.15407/steelcast2022.03.102","url":null,"abstract":"","PeriodicalId":33778,"journal":{"name":"Metall i lit''e Ukrainy","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43743482","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}