Sea sediments can be probed as records of the environment of sedimentation. Much attention has been given to clarifying the environment of sedimentation from an elemental composition point of view. Valuable information for paleoceanography has been obtained by several projects such as the Deep Sea Drilling Project and Ocean Drilling Program. In general, the rate of sedimentation in the sea is lower than rates in rivers or estuaries, except when there is a large scale variation such as massive climate change or an eruption of an undersea volcano in the sea area. There is less pelagic sediment deposition from terrigenous materials in the deep sea than on the coast. Therefore, the long term variation in the environment of the sea can be determined with the analysis of sediment cores of short length. Sea sediments comprise many kinds of heavy metals. Almost all iron supplied to the sea is included in the terrigenous fracture. These materials are carried and finally accumulate in the sea sequentially from the area along the shore through carriers such as the atmosphere and rivers. Since iron is an essential element for many sea organisms, which take in iron from seawater, organic matter as product of the food chain accumulate in the sediments. In this paper, we focus on the chemical states of iron in Antarctic sediments. From the analysis of Fe Mössbauer spectra, ferrous and ferric iron can be represented by silicate and clay minerals respectively. Uptake of iron from seawater by phytoplankton mainly causes a redox reaction in the cycle of photosynthesis and respiration. Consequently, the difference in chemical states such as ligand and valence states depends on the origin of the iron. In addition, chemical states of heavy metals such as iron and manganese in the sediments change upon reduction by organic matter. It is important to trace the processes of these reactions in discussing the environments of sediments. 2. Experimental
{"title":"57Fe Mössbauer Study of Specific Iron Species in the Antarctic Ocean Sediments","authors":"K. Shozugawa, A. Kuno, H. Miura, M. Matsuo","doi":"10.14494/JNRS.10.1_13","DOIUrl":"https://doi.org/10.14494/JNRS.10.1_13","url":null,"abstract":"Sea sediments can be probed as records of the environment of sedimentation. Much attention has been given to clarifying the environment of sedimentation from an elemental composition point of view. Valuable information for paleoceanography has been obtained by several projects such as the Deep Sea Drilling Project and Ocean Drilling Program. In general, the rate of sedimentation in the sea is lower than rates in rivers or estuaries, except when there is a large scale variation such as massive climate change or an eruption of an undersea volcano in the sea area. There is less pelagic sediment deposition from terrigenous materials in the deep sea than on the coast. Therefore, the long term variation in the environment of the sea can be determined with the analysis of sediment cores of short length. Sea sediments comprise many kinds of heavy metals. Almost all iron supplied to the sea is included in the terrigenous fracture. These materials are carried and finally accumulate in the sea sequentially from the area along the shore through carriers such as the atmosphere and rivers. Since iron is an essential element for many sea organisms, which take in iron from seawater, organic matter as product of the food chain accumulate in the sediments. In this paper, we focus on the chemical states of iron in Antarctic sediments. From the analysis of Fe Mössbauer spectra, ferrous and ferric iron can be represented by silicate and clay minerals respectively. Uptake of iron from seawater by phytoplankton mainly causes a redox reaction in the cycle of photosynthesis and respiration. Consequently, the difference in chemical states such as ligand and valence states depends on the origin of the iron. In addition, chemical states of heavy metals such as iron and manganese in the sediments change upon reduction by organic matter. It is important to trace the processes of these reactions in discussing the environments of sediments. 2. Experimental","PeriodicalId":16569,"journal":{"name":"Journal of nuclear and radiochemical sciences","volume":"7 1","pages":"13-17"},"PeriodicalIF":0.0,"publicationDate":"2009-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85204171","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":"99Mo/99mTc-113Sn/113mIn Dual Radioisotope Generator Based on 6-Tungstocerate(IV) Column Matrix","authors":"M. Mostafa, A. El-Sadek, H. El-Said, M. El-Amir","doi":"10.14494/JNRS.10.1_1","DOIUrl":"https://doi.org/10.14494/JNRS.10.1_1","url":null,"abstract":"","PeriodicalId":16569,"journal":{"name":"Journal of nuclear and radiochemical sciences","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2009-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90142267","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":"Relationship between Carbon-14 Concentrations in Tree-ring Cellulose and Atmospheric CO2","authors":"Y. Yamada, K. Yasuike, K. Komura","doi":"10.14494/JNRS.9.41","DOIUrl":"https://doi.org/10.14494/JNRS.9.41","url":null,"abstract":"","PeriodicalId":16569,"journal":{"name":"Journal of nuclear and radiochemical sciences","volume":"36 1","pages":"41-44"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78558528","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}
Doped transition metal compounds with complex electronic and magnetic structures show a wide range of new physical phenomena like high-temperature superconductivity, room temperature magnetic semiconductivity, or colossal magnetoresistance (CMR). Following the discovery of the effect of colossal negative magnetoresistance in manganese based perovskites, several different classes of transition metal compounds such as Sr2FeMoO6 double perovskites or La1-xSrxCoO3 perovskites were found to exhibit unusually high magnetoresistance (MR) partly as a peak around their Curie-temperature (CMR effect), partly as an increasing feature with decreasing temperature (tunneling-type magnetoresistance, TMR)(Table1). The most important difference between these two types of MR is their temperature dependence: while CMR effect manifests only around the magnetic temperature as a peak in the MR vs. T plot, TMR increases monotonically with decreasing temperature. Due to the complexity of the underlying physical and chemical processes in these materials, the understanding of their electronic and magnetic structure is one of the most vital topics in condensed matter physics nowadays. The first models aiming to shed light on the CMR effect found in manganite perovskites, and to explain the unusually strong correlation between the magnetic state of the material and its electric transport properties were based on the theories of double exchange model and strong electron-lattice interactions. The former was based on the fact that in La1-xCaxMnO3 perovskites the doping divalent ions (usually Ca) introduce a number of x extra electrons to the system, either oxidizing Mn ions into Mn or creating oxygen vacancies, although for low doping rates the latter effect was found to be negligible. As a Mossbauer Studies for Exploring CMR and TMR Perovskites
具有复杂电子和磁性结构的掺杂过渡金属化合物表现出一系列新的物理现象，如高温超导性、室温磁半导体性或巨磁电阻(CMR)。在发现锰基钙钛矿的巨大负磁电阻效应之后，几种不同类型的过渡金属化合物，如Sr2FeMoO6双钙钛矿或La1-xSrxCoO3钙钛矿，被发现表现出异常高的磁电阻(MR)，部分表现为居里温度附近的峰值(CMR效应)，部分表现为随温度降低而增加的特征(隧道型磁电阻，TMR)(表1)。这两种类型的MR之间最重要的区别在于它们的温度依赖性:CMR效应仅在磁温周围表现为MR vs. T图中的峰值，而TMR则随着温度的降低而单调增加。由于这些材料中潜在的物理和化学过程的复杂性，对它们的电子和磁性结构的理解是当今凝聚态物理学中最重要的主题之一。基于双交换模型和强电子-晶格相互作用理论的第一个模型旨在揭示在锰矿钙钛矿中发现的CMR效应，并解释材料的磁性状态与其电输运性质之间异常强的相关性。前者是基于这样一个事实，即在La1-xCaxMnO3钙钛矿中，掺杂的二价离子(通常是Ca)向体系引入了大量x个额外的电子，要么将Mn离子氧化成Mn，要么产生氧空位，尽管在低掺杂率下，后者的影响被发现可以忽略不计。作为探索CMR和TMR钙钛矿的穆斯堡尔研究
{"title":"Mössbauer Studies for Exploring CMR and TMR Perovskites","authors":"Z. Nemeth, Z. Klencsár, A. Vertes, K. Nomura","doi":"10.14494/JNRS.9.R1","DOIUrl":"https://doi.org/10.14494/JNRS.9.R1","url":null,"abstract":"Doped transition metal compounds with complex electronic and magnetic structures show a wide range of new physical phenomena like high-temperature superconductivity, room temperature magnetic semiconductivity, or colossal magnetoresistance (CMR). Following the discovery of the effect of colossal negative magnetoresistance in manganese based perovskites, several different classes of transition metal compounds such as Sr2FeMoO6 double perovskites or La1-xSrxCoO3 perovskites were found to exhibit unusually high magnetoresistance (MR) partly as a peak around their Curie-temperature (CMR effect), partly as an increasing feature with decreasing temperature (tunneling-type magnetoresistance, TMR)(Table1). The most important difference between these two types of MR is their temperature dependence: while CMR effect manifests only around the magnetic temperature as a peak in the MR vs. T plot, TMR increases monotonically with decreasing temperature. Due to the complexity of the underlying physical and chemical processes in these materials, the understanding of their electronic and magnetic structure is one of the most vital topics in condensed matter physics nowadays. The first models aiming to shed light on the CMR effect found in manganite perovskites, and to explain the unusually strong correlation between the magnetic state of the material and its electric transport properties were based on the theories of double exchange model and strong electron-lattice interactions. The former was based on the fact that in La1-xCaxMnO3 perovskites the doping divalent ions (usually Ca) introduce a number of x extra electrons to the system, either oxidizing Mn ions into Mn or creating oxygen vacancies, although for low doping rates the latter effect was found to be negligible. As a Mossbauer Studies for Exploring CMR and TMR Perovskites","PeriodicalId":16569,"journal":{"name":"Journal of nuclear and radiochemical sciences","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84174993","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}
clarity, the structures of these compounds are collected in scheme 1. In the present study, these compounds have been investigated by temperature-dependent MES and the dynamical data concerning the iron atom(s) have been compared to the temperature factor Ui,j values determined by single crystal X-ray diffraction. A comparison between the MES and X-ray based data relating to the vibrational amplitudes of the metal atom in organometallics should consider the effect of lattice imperfections which play a more significant role in the magnitude of the Ui,j values extracted from X-ray diffraction data than in the mean-square-amplitude-of-vibration data contributing the the recoil-free fraction (MES) values. Inter-molecular motions will contribute more to the former than the latter, since the X-ray measurements sample all atomic positions over a lengthy period of time while the MES measurements involve only a single atom during the scattering event. It should also be noted that the presence of solvate molecules in the unit cell will influence the atomic positions sensed by the X-ray technique relative to the MES measurements. This point will be addressed again in the discussion to follow. Hence, in general the vibrational amplitudes calculated from the X-ray data are larger than those derived from the MES data at the same temperature, as will be discussed in greater detail, below. This observation has also been examined in detail in relation to protein dynamics by Parak et al. 8 The second point relates to the temperature dependence of the vibrational amplitudes. The frequency of such vibrations can be expressed as ω ∝ [k/M] 1/2 where k is the appropriate force constant and M is the vibrating mass. For intra-molecular motions, k is large and M is small (relatively), whereas for inter-molecular motions, k is small and M is large. Thus, at low temperatures where the phonon frequencies are low, the major contribution to the vibrational amplitude will be due to the inter-molecular motions, while with increasing temperature the intra-molecular motions become more appreciable. These considerations lead to the expectation that the tempera
{"title":"Hyperfine Interactions and Metal Atom Dynamic Effects of Pentafluorophenyl Substituents on Ferrocene Complexes","authors":"R. Herber, I. Nowik","doi":"10.14494/JNRS.9.33","DOIUrl":"https://doi.org/10.14494/JNRS.9.33","url":null,"abstract":"clarity, the structures of these compounds are collected in scheme 1. In the present study, these compounds have been investigated by temperature-dependent MES and the dynamical data concerning the iron atom(s) have been compared to the temperature factor Ui,j values determined by single crystal X-ray diffraction. A comparison between the MES and X-ray based data relating to the vibrational amplitudes of the metal atom in organometallics should consider the effect of lattice imperfections which play a more significant role in the magnitude of the Ui,j values extracted from X-ray diffraction data than in the mean-square-amplitude-of-vibration data contributing the the recoil-free fraction (MES) values. Inter-molecular motions will contribute more to the former than the latter, since the X-ray measurements sample all atomic positions over a lengthy period of time while the MES measurements involve only a single atom during the scattering event. It should also be noted that the presence of solvate molecules in the unit cell will influence the atomic positions sensed by the X-ray technique relative to the MES measurements. This point will be addressed again in the discussion to follow. Hence, in general the vibrational amplitudes calculated from the X-ray data are larger than those derived from the MES data at the same temperature, as will be discussed in greater detail, below. This observation has also been examined in detail in relation to protein dynamics by Parak et al. 8 The second point relates to the temperature dependence of the vibrational amplitudes. The frequency of such vibrations can be expressed as ω ∝ [k/M] 1/2 where k is the appropriate force constant and M is the vibrating mass. For intra-molecular motions, k is large and M is small (relatively), whereas for inter-molecular motions, k is small and M is large. Thus, at low temperatures where the phonon frequencies are low, the major contribution to the vibrational amplitude will be due to the inter-molecular motions, while with increasing temperature the intra-molecular motions become more appreciable. These considerations lead to the expectation that the tempera","PeriodicalId":16569,"journal":{"name":"Journal of nuclear and radiochemical sciences","volume":"27 1","pages":"33-36"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81158991","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}
The activation of gold by environmental neutrons was used to study the effect of concrete buildings at our laboratory (LLRL) on the neutron flux, and to estimate the thermal neutron flux in and around the building of Kinki University Training Reactor (UTRKinki). The results showed that three ceilings of thickness (34 g/cm each) decrease the fast neutrons to 26 %. However, the same reinforced concrete decreases the slow flux to only 62 %. On the other hand, the thermal neutron flux at 283m from the reactor center was two times higher than the environmental background. These results can give attention to the effect of concrete walls as a shielding around the reactors, especially those that have been hold near to the living environments.
{"title":"Some Applications of the Gold Activation by Environmental Neutrons","authors":"K. Komura, N. K. Ahmed, A. H. El-Kamel, A. Yousef","doi":"10.14494/JNRS.9.49","DOIUrl":"https://doi.org/10.14494/JNRS.9.49","url":null,"abstract":"The activation of gold by environmental neutrons was used to study the effect of concrete buildings at our laboratory (LLRL) on the neutron flux, and to estimate the thermal neutron flux in and around the building of Kinki University Training Reactor (UTRKinki). The results showed that three ceilings of thickness (34 g/cm each) decrease the fast neutrons to 26 %. However, the same reinforced concrete decreases the slow flux to only 62 %. On the other hand, the thermal neutron flux at 283m from the reactor center was two times higher than the environmental background. These results can give attention to the effect of concrete walls as a shielding around the reactors, especially those that have been hold near to the living environments.","PeriodicalId":16569,"journal":{"name":"Journal of nuclear and radiochemical sciences","volume":"19 1","pages":"49-52"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87906439","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}
As a part of interest in the study of the neutron flux in biological environments, variations of slow neutrons with depth of water and soil were measured through the radioactivity induced in gold by 197 Au(n, (cid:1) ) 198 Au interaction. The measurements made for 0-100 cm in fresh water and 20-400 cm in sea water showed that the thermal neutron flux showed peak at around 10 cm depth and then gradually decreased with depth in water. The depth profiles in seawater were almost the same profile as freshwater. In the case of soil made for 0-60 cm, thermal neutron flux showed a peak at 5 cm then through a shoulder-like decrease during 10~30 cm range and decreased with depth gradually rapidly to 60 cm.
{"title":"Variation of Environmental Neutron Flux with the Depth of Water and Soil","authors":"K. Komura, N. K. Ahmed, A.H.El-Kamel, M. Yousef","doi":"10.14494/JNRS.9.45","DOIUrl":"https://doi.org/10.14494/JNRS.9.45","url":null,"abstract":"As a part of interest in the study of the neutron flux in biological environments, variations of slow neutrons with depth of water and soil were measured through the radioactivity induced in gold by 197 Au(n, (cid:1) ) 198 Au interaction. The measurements made for 0-100 cm in fresh water and 20-400 cm in sea water showed that the thermal neutron flux showed peak at around 10 cm depth and then gradually decreased with depth in water. The depth profiles in seawater were almost the same profile as freshwater. In the case of soil made for 0-60 cm, thermal neutron flux showed a peak at 5 cm then through a shoulder-like decrease during 10~30 cm range and decreased with depth gradually rapidly to 60 cm.","PeriodicalId":16569,"journal":{"name":"Journal of nuclear and radiochemical sciences","volume":"104 1","pages":"45-47"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79230047","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}
Ago Bay in Mie Prefecture, central Japan, is world-famous for the site of Mikimoto pearl culture, but recently the production of pearls has considerably declined. Environmental deterioration of the bay is suspected of having caused the decline. The periodic investigation into iron speciation of the bay sediment by 57 Fe Mossbauer spectroscopy revealed its high pyrite (FeS2) content from the surface to the 20-cm depth. The pyrite in the surface sediment decreased only in spring, three months after the dissolved oxygen in the bottom water was at maximum. Such oxygen-consuming material as pyrite accumulated through long-term biotic activity is a most-likely explanation for the prolonged environmental deterioration of the bay, which appears in the high chemical oxygen demand (COD) of the sediment.
{"title":"Seasonal Variation of Iron Speciation in a Pearl-Raising Bay Sediment by Mössbauer Spectroscopy","authors":"A. Kuno, M. Matsuo, S. Chiba, Y. Yamagata","doi":"10.14494/jnrs.9.13","DOIUrl":"https://doi.org/10.14494/jnrs.9.13","url":null,"abstract":"Ago Bay in Mie Prefecture, central Japan, is world-famous for the site of Mikimoto pearl culture, but recently the production of pearls has considerably declined. Environmental deterioration of the bay is suspected of having caused the decline. The periodic investigation into iron speciation of the bay sediment by 57 Fe Mossbauer spectroscopy revealed its high pyrite (FeS2) content from the surface to the 20-cm depth. The pyrite in the surface sediment decreased only in spring, three months after the dissolved oxygen in the bottom water was at maximum. Such oxygen-consuming material as pyrite accumulated through long-term biotic activity is a most-likely explanation for the prolonged environmental deterioration of the bay, which appears in the high chemical oxygen demand (COD) of the sediment.","PeriodicalId":16569,"journal":{"name":"Journal of nuclear and radiochemical sciences","volume":"13 1","pages":"13-18"},"PeriodicalIF":0.0,"publicationDate":"2008-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91543400","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}
S. D. Partha, R. Acharya, A. Nair, S. Lakshminarayana, D. Lakshmana, A. Reddy
{"title":"Application of Instrumental Neutron Activation Analysis for Chemical Composition Analysis of Ancient Potteries from Buddhist Sites of Andhra Pradesh : Part I","authors":"S. D. Partha, R. Acharya, A. Nair, S. Lakshminarayana, D. Lakshmana, A. Reddy","doi":"10.14494/jnrs.9.7","DOIUrl":"https://doi.org/10.14494/jnrs.9.7","url":null,"abstract":"","PeriodicalId":16569,"journal":{"name":"Journal of nuclear and radiochemical sciences","volume":"28 1","pages":"7-12"},"PeriodicalIF":0.0,"publicationDate":"2008-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85140133","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":"Empirical Formulas for Estimation of Fission Prompt Neutron Multiplicity for Actinide Nuclides","authors":"T. Ohsawa","doi":"10.14494/jnrs.9.19","DOIUrl":"https://doi.org/10.14494/jnrs.9.19","url":null,"abstract":"","PeriodicalId":16569,"journal":{"name":"Journal of nuclear and radiochemical sciences","volume":"10 1","pages":"19-25"},"PeriodicalIF":0.0,"publicationDate":"2008-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85541691","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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