To avoid potentially harmful wet sample preparation is offered to use laser ablation (LA) ‒ inductively coupled plasma ‒ optical emission spectrometry (ICP-OES) as a method for the elemental analysis of fly ash for boron, lithium, and some metals. For this purpose, synthetic samples were prepared by spiking with dissolved standards. As a result, great stability of calibration curves was achieved. It was found that a particle diameter less than 80 μm in fly ash is enough to have a satisfying homogeneity for successful calibration in the method of standard additions. The average recovery test for reference materials used in the study was 16–77% of the certified values for the elements observed. The low results might be the effect of spiking with calibration samples in the liquid state. This type of analysis requires further investigation. According to the results of elemental analysis, the content of boron and lithium was determined for ZUK-2 and SO-1, which was not previously noticed in other papers.
{"title":"Determination of Boron, Lithium and Some Metals in Fly Ash by Laser Ablation ‒ Inductively Coupled Plasma ‒ Optical Emission Spectr ometry","authors":"R. Kolmykov","doi":"10.18321/ectj1324","DOIUrl":"https://doi.org/10.18321/ectj1324","url":null,"abstract":"To avoid potentially harmful wet sample preparation is offered to use laser ablation (LA) ‒ inductively coupled plasma ‒ optical emission spectrometry (ICP-OES) as a method for the elemental analysis of fly ash for boron, lithium, and some metals. For this purpose, synthetic samples were prepared by spiking with dissolved standards. As a result, great stability of calibration curves was achieved. It was found that a particle diameter less than 80 μm in fly ash is enough to have a satisfying homogeneity for successful calibration in the method of standard additions. The average recovery test for reference materials used in the study was 16–77% of the certified values for the elements observed. The low results might be the effect of spiking with calibration samples in the liquid state. This type of analysis requires further investigation. According to the results of elemental analysis, the content of boron and lithium was determined for ZUK-2 and SO-1, which was not previously noticed in other papers.","PeriodicalId":11795,"journal":{"name":"Eurasian Chemico-Technological Journal","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43398048","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}
E. Kachina, N. Ivanova, Y. Zakharov, G. Simenyuk, Z. Ismagilov, M. Lomakin
A simple and reproducible method of chemical deposition was used to modify carbon nanotubes cobalt and nickel hydroxides. Thus the composites containing 5 and 10 wt.% Co0.5Ni0.5(OH)2(the ratio of hydroxides1:1)were obtained based on the matrix of multiwall carbon nanotubes: non-functionalized (MWCNT) and functionalized (MWCNT-f). The physicochemical properties of the obtained nanocomposites were investigated with a focus on the characteristics that are relevant for use as the electrode materials of supercapacitors. Electrical capacity characteristics (specific electrical capacitance, internal resistance, etc.) of nanocomposites were determined using cyclic voltammetry and impedancemetry. The effect of matrix functionalization and filler content on the electrochemical characteristics of the composites was considered. It is established that the surface of carbon nanotubes allows the accumulation of the charge in the electrical double layer, in particular at high polarization rates. At low rates, the contribution from the pseudo-capacity component increases on the filler nanoparticles, on the surface of channels in nanotubes, and pore surface in hydroxide aggregates. An increase in the specific electrical capacitance of the composites by a factor of 1.5 to the capacitance of MWCNTs was achieved. The schemes of electrode processes in the nanocomposite are proposed, and the nature of redox peaks on voltammetric curves providing the occurrence of the pseudo-capacity component is revealed. Relying on the analysis of impedancemetry results, the equivalent series resistance and the charge transfer resistance are evaluated. An equivalent circuit of the cell with the working composite electrode is proposed, and its major parameters are calculated.
{"title":"Electrochemical Properties of the Composites Based on Multiwall Carbon Nanotubes Modified with Nanoparticles of Mixed Cobalt and Nickel Hydroxides","authors":"E. Kachina, N. Ivanova, Y. Zakharov, G. Simenyuk, Z. Ismagilov, M. Lomakin","doi":"10.18321/ectj1323","DOIUrl":"https://doi.org/10.18321/ectj1323","url":null,"abstract":"A simple and reproducible method of chemical deposition was used to modify carbon nanotubes cobalt and nickel hydroxides. Thus the composites containing 5 and 10 wt.% Co0.5Ni0.5(OH)2(the ratio of hydroxides1:1)were obtained based on the matrix of multiwall carbon nanotubes: non-functionalized (MWCNT) and functionalized (MWCNT-f). The physicochemical properties of the obtained nanocomposites were investigated with a focus on the characteristics that are relevant for use as the electrode materials of supercapacitors. Electrical capacity characteristics (specific electrical capacitance, internal resistance, etc.) of nanocomposites were determined using cyclic voltammetry and impedancemetry. The effect of matrix functionalization and filler content on the electrochemical characteristics of the composites was considered. It is established that the surface of carbon nanotubes allows the accumulation of the charge in the electrical double layer, in particular at high polarization rates. At low rates, the contribution from the pseudo-capacity component increases on the filler nanoparticles, on the surface of channels in nanotubes, and pore surface in hydroxide aggregates. An increase in the specific electrical capacitance of the composites by a factor of 1.5 to the capacitance of MWCNTs was achieved. The schemes of electrode processes in the nanocomposite are proposed, and the nature of redox peaks on voltammetric curves providing the occurrence of the pseudo-capacity component is revealed. Relying on the analysis of impedancemetry results, the equivalent series resistance and the charge transfer resistance are evaluated. An equivalent circuit of the cell with the working composite electrode is proposed, and its major parameters are calculated.","PeriodicalId":11795,"journal":{"name":"Eurasian Chemico-Technological Journal","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43637151","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}
Е. Matus, I. Ismagilov, E. Mikhaylova, Z. Ismagilov
Coal industry methane is a fossil raw material that can serve as an energy carrier for the production of heat and electricity, as well as a raw material for obtaining valuable products for the chemical industry. To ensure the safety of coal mining, rational environmental management and curbing global warming, it is important to develop and improve methods for capturing and utilizing methane from the coal industry. This review looks at the scientific basis and promising technologies for hydrogen production from coal industry methane and coal production. Technologies for catalytic conversion of all types of coal industry methane (Ventilation Air Methane – VAM, Coal Mine Methane – CMM, Abandoned Mine Methane – AMM, Coal-Bed Methane – CBM), differing in methane concentration and methane-to-air ratio, are discussed. The results of studies on the creation of a number of efficient catalysts for hydrogen production are presented. The great potential of hybrid methods of processing natural coal and coal industry methane has been demonstrated.
{"title":"Hydrogen Production from Coal Industry Methane","authors":"Е. Matus, I. Ismagilov, E. Mikhaylova, Z. Ismagilov","doi":"10.18321/ectj1320","DOIUrl":"https://doi.org/10.18321/ectj1320","url":null,"abstract":"Coal industry methane is a fossil raw material that can serve as an energy carrier for the production of heat and electricity, as well as a raw material for obtaining valuable products for the chemical industry. To ensure the safety of coal mining, rational environmental management and curbing global warming, it is important to develop and improve methods for capturing and utilizing methane from the coal industry. This review looks at the scientific basis and promising technologies for hydrogen production from coal industry methane and coal production. Technologies for catalytic conversion of all types of coal industry methane (Ventilation Air Methane – VAM, Coal Mine Methane – CMM, Abandoned Mine Methane – AMM, Coal-Bed Methane – CBM), differing in methane concentration and methane-to-air ratio, are discussed. The results of studies on the creation of a number of efficient catalysts for hydrogen production are presented. The great potential of hybrid methods of processing natural coal and coal industry methane has been demonstrated.","PeriodicalId":11795,"journal":{"name":"Eurasian Chemico-Technological Journal","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47802418","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}
E. Zhuravleva, N. Zhuravleva, E. Mikhaylova, Z. Ismagilov, M. Shashkov, P. A. Dolgushev
Results of the investigation of polycyclic aromatic hydrocarbons (PAHs) content in fine coal powders prepared according to a special procedure within size classes (-0.2+0.1) mm, (-0.1+0.063) mm, (-0.063+0.04) mm, (-0.04) mm for ten different coal ranks (B, D, G, Zh, K, KS, OS, SS, T, A) from the Kuznetsk coal basin are presented. The qualitative and quantitative PAHs content in coal samples was determined by means of GC-MS using a SCION SQ SELECT instrument (Bruker, USA). The maximal Σ14 PAHs content is observed for A rank coal (224.3 mg/kg), KS (201.9 mg/kg) and T (197.8 mg/ kg), and the minimal Σ14 PAHs content is detected for B rank (2.2 mg/kg) for the size fraction (-0.04) mm. The concentration of benz(a)pyrene, which is a strong carcinogen, is within the range of 0.026‒103.1 mg/kg in coal samples under investigation. At the same time, the fraction of benz(a)pyrene is less than 45% of the total amount of detected PAHs, and it is less stable to the effect of the environment than other PAHs. The most stable component in PAHs series is phenanthrene, which was detected in the series of studied coal samples of different fractions (0.061‒43.7 mg/kg). Phenanthrene may be considered a PAHs of priority, and it may be used as a reference compound to evaluate the influence of coal mining and processing on the environment. The group composition of hydrocarbons in coal extracts was determined by means of two-dimensional gas chromatography with flame ionization detection.
{"title":"Determination of Polycyclic Aromatic Hydrocarbons in Coal from the Kuznetsk Coal Basin by Means of GC/MS and GC/GC-FID","authors":"E. Zhuravleva, N. Zhuravleva, E. Mikhaylova, Z. Ismagilov, M. Shashkov, P. A. Dolgushev","doi":"10.18321/ectj1322","DOIUrl":"https://doi.org/10.18321/ectj1322","url":null,"abstract":"Results of the investigation of polycyclic aromatic hydrocarbons (PAHs) content in fine coal powders prepared according to a special procedure within size classes (-0.2+0.1) mm, (-0.1+0.063) mm, (-0.063+0.04) mm, (-0.04) mm for ten different coal ranks (B, D, G, Zh, K, KS, OS, SS, T, A) from the Kuznetsk coal basin are presented. The qualitative and quantitative PAHs content in coal samples was determined by means of GC-MS using a SCION SQ SELECT instrument (Bruker, USA). The maximal Σ14 PAHs content is observed for A rank coal (224.3 mg/kg), KS (201.9 mg/kg) and T (197.8 mg/ kg), and the minimal Σ14 PAHs content is detected for B rank (2.2 mg/kg) for the size fraction (-0.04) mm. The concentration of benz(a)pyrene, which is a strong carcinogen, is within the range of 0.026‒103.1 mg/kg in coal samples under investigation. At the same time, the fraction of benz(a)pyrene is less than 45% of the total amount of detected PAHs, and it is less stable to the effect of the environment than other PAHs. The most stable component in PAHs series is phenanthrene, which was detected in the series of studied coal samples of different fractions (0.061‒43.7 mg/kg). Phenanthrene may be considered a PAHs of priority, and it may be used as a reference compound to evaluate the influence of coal mining and processing on the environment. The group composition of hydrocarbons in coal extracts was determined by means of two-dimensional gas chromatography with flame ionization detection.","PeriodicalId":11795,"journal":{"name":"Eurasian Chemico-Technological Journal","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45068311","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}
Data on the synthesis of carbon-mineral materials (CMM) through carbonization of native sapropel after preliminary mechanical activation (MA) in the air environment are presented. The effect of MA parameters (time, the size and acceleration of milling bodies) on the fractional composition and morphology of sapropel is investigated. MA for 5‒10 min promotes the dispersion of sapropel particles, while a further increase in treatment time causes their partial agglomeration. It is demonstrated that preliminary MA of native sapropel leads to changes in the texture parameters and acidity of the surface of CMM obtained after the carbonization stage. An increase in specific surface area from 90 to 560 m2g-1 is observed, with an increase in the adsorption pore volume from 0.16 to 0.52 cm3g-1 as a result of an increase in the fraction of micropores in the formed CMM. Despite this fact, CMM samples still contain large pores, and the fraction of meso- and macropores is 70%. In addition, a decrease in pH of the point of zero charge occurs as a consequence of an increase in the content of acidic oxygen-containing groups. The discovered effect is essential for the formation of sapropel-based materials with required properties and for broadening their application area.
{"title":"Mechanical Activation as a Method to Regulate Morphology, Texture and Surface Functional Composition of Carbon-Mineral Materials Derived from Sapropel","authors":"O. I. Krivonos, O. Belskaya, V. Likholobov","doi":"10.18321/ectj1325","DOIUrl":"https://doi.org/10.18321/ectj1325","url":null,"abstract":"Data on the synthesis of carbon-mineral materials (CMM) through carbonization of native sapropel after preliminary mechanical activation (MA) in the air environment are presented. The effect of MA parameters (time, the size and acceleration of milling bodies) on the fractional composition and morphology of sapropel is investigated. MA for 5‒10 min promotes the dispersion of sapropel particles, while a further increase in treatment time causes their partial agglomeration. It is demonstrated that preliminary MA of native sapropel leads to changes in the texture parameters and acidity of the surface of CMM obtained after the carbonization stage. An increase in specific surface area from 90 to 560 m2g-1 is observed, with an increase in the adsorption pore volume from 0.16 to 0.52 cm3g-1 as a result of an increase in the fraction of micropores in the formed CMM. Despite this fact, CMM samples still contain large pores, and the fraction of meso- and macropores is 70%. In addition, a decrease in pH of the point of zero charge occurs as a consequence of an increase in the content of acidic oxygen-containing groups. The discovered effect is essential for the formation of sapropel-based materials with required properties and for broadening their application area.","PeriodicalId":11795,"journal":{"name":"Eurasian Chemico-Technological Journal","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43544421","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}
M. Kulikova, M. Chudakova, M. Ivantsov, О.S. Dementyva, A. Maksimov
Carbon materials were formed by the hydrothermal carbonization of cellulose, which were used as support for carbon dioxide hydrogenation catalysts (Fe/C and Fe-Mn/C). In the presence of these catalytic systems, CO2 conversion reached 50%. It is shown that the manganese introduction into the Fe-containing catalytic system significantly affects the distribution of gaseous С1-С4 products and liquid С5+ hydrocarbons. Promotion leads to the suppression of methane formation and an increase in the proportion of C2-C4 light olefins in gaseous products, as well as to intensification of secondary processes with the formation of a significant amount of iso-structures in liquid products. The different distribution of С1-С6 alcohols in the oxygen-containing products on the Fe/C and Fe-Mn/C catalysts indicates the manganese effect on the routes of their formation.
{"title":"Hydrocarbon Synthesis from CO2 and H2 Using the Ultrafine Iron-Containing Catalytic Systems Based on Carbonized Cellulose","authors":"M. Kulikova, M. Chudakova, M. Ivantsov, О.S. Dementyva, A. Maksimov","doi":"10.18321/ectj1327","DOIUrl":"https://doi.org/10.18321/ectj1327","url":null,"abstract":"Carbon materials were formed by the hydrothermal carbonization of cellulose, which were used as support for carbon dioxide hydrogenation catalysts (Fe/C and Fe-Mn/C). In the presence of these catalytic systems, CO2 conversion reached 50%. It is shown that the manganese introduction into the Fe-containing catalytic system significantly affects the distribution of gaseous С1-С4 products and liquid С5+ hydrocarbons. Promotion leads to the suppression of methane formation and an increase in the proportion of C2-C4 light olefins in gaseous products, as well as to intensification of secondary processes with the formation of a significant amount of iso-structures in liquid products. The different distribution of С1-С6 alcohols in the oxygen-containing products on the Fe/C and Fe-Mn/C catalysts indicates the manganese effect on the routes of their formation.","PeriodicalId":11795,"journal":{"name":"Eurasian Chemico-Technological Journal","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49475699","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}
B. Aduev, G. Belokurov, I. Liskov, D. Nurmukhametov, Z. Ismagilov
The paper presents the results of a comparative investigation into the kinetic and energy characteristics of the ignition of microparticles of low-metamorphized coal ranks (lignite coal and high volatile C bituminous coal) under the impact of laser radiation at the wavelengths λ = 450 nm and λ = 808 nm with an exposure time of 1 sec. Coal ignition is carried out only during irradiation. There is no transition to stationary combustion. The ignition delay time decreases monotonically with increasing radiation power density. It is established that the energy costs of ignition of the studied coal ranks may be made more economical by using laser radiation with a wavelength of λ = 450 nm. It is concluded from the results of measuring the energy characteristics of coal ignition that the absorption of radiation has a quantum nature. Two components contribute to the coal particles emission spectra measured at the initial stage of ignition: CO (CO2*) flame and thermal glow associated with emitted carbon particles heated to T>2000 K for both coal ranks. At subsequent stages, only the glow of heated carbon particles with the thermal spectrum at T~2000 K is observed in the spectra.
{"title":"Ignition of Low-Metamorphized Coal with Continuous Lasers at Wavelengths 450 nm and 808 nm","authors":"B. Aduev, G. Belokurov, I. Liskov, D. Nurmukhametov, Z. Ismagilov","doi":"10.18321/ectj1321","DOIUrl":"https://doi.org/10.18321/ectj1321","url":null,"abstract":"The paper presents the results of a comparative investigation into the kinetic and energy characteristics of the ignition of microparticles of low-metamorphized coal ranks (lignite coal and high volatile C bituminous coal) under the impact of laser radiation at the wavelengths λ = 450 nm and λ = 808 nm with an exposure time of 1 sec. Coal ignition is carried out only during irradiation. There is no transition to stationary combustion. The ignition delay time decreases monotonically with increasing radiation power density. It is established that the energy costs of ignition of the studied coal ranks may be made more economical by using laser radiation with a wavelength of λ = 450 nm. It is concluded from the results of measuring the energy characteristics of coal ignition that the absorption of radiation has a quantum nature. Two components contribute to the coal particles emission spectra measured at the initial stage of ignition: CO (CO2*) flame and thermal glow associated with emitted carbon particles heated to T>2000 K for both coal ranks. At subsequent stages, only the glow of heated carbon particles with the thermal spectrum at T~2000 K is observed in the spectra.","PeriodicalId":11795,"journal":{"name":"Eurasian Chemico-Technological Journal","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41691572","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}
V. Merkulov, A.I. Almazov, S. Kabiyeva, S. Mantler, V. Konshin
The article is devoted to research on the synthesis of hydroxyquinoline derivative based on 8-oxyquinoline and maleic anhydride. Analysis of available literature was carried out, some drugs were found that are produced based on hydroxyquinoline derivatives and have antiprotozoal, antimicrobial and antiseptic effects, used alone or in combination with other active substances. A technique has been developed for the synthesis of a new derivative in the medium of petroleum distillate using sulfuric acid as a catalyst. A water-soluble ester of 8-oxyquinoline and maleic acid was obtained in good yield (95%), the structure of which was established based on UV, IR and NMR spectroscopy. By analogy with other oxyquinoline derivatives and the results of prediction bioactivity in the PASS program, the obtained derivative may be characterized by antifungal (antiseborrheic) action. It was determined its antibacterial properties at a concentration of 20.0–10.0 mg/cm3 as well as a significant antioxidant activity which is a useful biological property to expand the range of its application.
{"title":"A Simple Procedure for Synthesis of Biological Active \u00004-oxo-4-(quinolin-8-yloxy)but-2-enoic acid","authors":"V. Merkulov, A.I. Almazov, S. Kabiyeva, S. Mantler, V. Konshin","doi":"10.18321/ectj1148","DOIUrl":"https://doi.org/10.18321/ectj1148","url":null,"abstract":"The article is devoted to research on the synthesis of hydroxyquinoline derivative based on 8-oxyquinoline and maleic anhydride. Analysis of available literature was carried out, some drugs were found that are produced based on hydroxyquinoline derivatives and have antiprotozoal, antimicrobial and antiseptic effects, used alone or in combination with other active substances. A technique has been developed for the synthesis of a new derivative in the medium of petroleum distillate using sulfuric acid as a catalyst. A water-soluble ester of 8-oxyquinoline and maleic acid was obtained in good yield (95%), the structure of which was established based on UV, IR and NMR spectroscopy. By analogy with other oxyquinoline derivatives and the results of prediction bioactivity in the PASS program, the obtained derivative may be characterized by antifungal (antiseborrheic) action. It was determined its antibacterial properties at a concentration of 20.0–10.0 mg/cm3 as well as a significant antioxidant activity which is a useful biological property to expand the range of its application.","PeriodicalId":11795,"journal":{"name":"Eurasian Chemico-Technological Journal","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49434137","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}