A study has been made of the electrostatics of the haematite (α-Fe2O3)/aqueous electrolyte solution interface. The haematite was a synthetic sample. Its surface properties have been characterized by several independent methods. There are positive indications of porosity. Surface-charge pH curves have been obtained by potentiometric titration. These measurements have been amplified by sol stability studies. Special attention has been paid to the influence of the nature of the electrolyte (KNO3, KCl, K2SO4, LiCl, CsCl, and the nitrates of Mg2+, Ca2+, Sr2+, and Ba2+). It appears that the electrical double layer on haematite has properties between those of silver iodide and mercury and those on silica.
{"title":"Interfacial electrochemistry of haematite (α-Fe2O3)","authors":"A. Breeuwsma, J. Lyklema","doi":"10.1039/DF9715200324","DOIUrl":"https://doi.org/10.1039/DF9715200324","url":null,"abstract":"A study has been made of the electrostatics of the haematite (α-Fe2O3)/aqueous electrolyte solution interface. The haematite was a synthetic sample. Its surface properties have been characterized by several independent methods. There are positive indications of porosity. Surface-charge pH curves have been obtained by potentiometric titration. These measurements have been amplified by sol stability studies. Special attention has been paid to the influence of the nature of the electrolyte (KNO3, KCl, K2SO4, LiCl, CsCl, and the nitrates of Mg2+, Ca2+, Sr2+, and Ba2+). It appears that the electrical double layer on haematite has properties between those of silver iodide and mercury and those on silica.","PeriodicalId":11262,"journal":{"name":"Discussions of The Faraday Society","volume":"44 1","pages":"324-333"},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80603243","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}
D. Bonniface, M. J. Braithwaite, D. D. Eley, R. G. Evans, R. Pethig, M. Willis
Conductivity measurements are reported on both isotactic and atactic polyvinyl pyridinium complex TCNQ salts. The isotactic materials are significantly better conductors than those derived from atactic materials, but not as good as those derived from the monomeric base. Seebeck and microwave Hall mobility measurements indicate that the isotactic materials behave as polycrystalline complex radical salts, whereas the atactic materials exhibit behaviour consistent with hopping conduction.
{"title":"Factors affecting conduction in polymeric complex TCNQ salts","authors":"D. Bonniface, M. J. Braithwaite, D. D. Eley, R. G. Evans, R. Pethig, M. Willis","doi":"10.1039/DF9715100131","DOIUrl":"https://doi.org/10.1039/DF9715100131","url":null,"abstract":"Conductivity measurements are reported on both isotactic and atactic polyvinyl pyridinium complex TCNQ salts. The isotactic materials are significantly better conductors than those derived from atactic materials, but not as good as those derived from the monomeric base. Seebeck and microwave Hall mobility measurements indicate that the isotactic materials behave as polycrystalline complex radical salts, whereas the atactic materials exhibit behaviour consistent with hopping conduction.","PeriodicalId":11262,"journal":{"name":"Discussions of The Faraday Society","volume":"76 1","pages":"131-138"},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80151548","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}
P. Gravelle, F. Juillet, P. Mériaudeau, S. Teichner
A moderate surface reduction of TiO2(anatase or rutile) at 573–773 K under vacuum, or in the presence of carbon monoxide or hydrogen, or finally at room temperature under ultra-violet irradiation in vacuum or in the presence of hydrocarbons, creates two types of paramagnetic centres, which are identified by e.s.r. spectra as Ti3+ ions.Adsorption of oxygen (between 77 and 373 K) on TiO2 samples reduced in the ways described above leads to the formation of ionic species of the type O–2. The same species are also formed at room temperature on unreduced TiO2 samples submitted to an UV irradiation in the range of 2000–6000 A.These results are paralleled with the occurrence of photocatalytic (in u.-v.) partial oxidation of isobutane on TiO2 at room temperature.
{"title":"Surface reactivity of reduced titanium dioxide","authors":"P. Gravelle, F. Juillet, P. Mériaudeau, S. Teichner","doi":"10.1039/DF9715200140","DOIUrl":"https://doi.org/10.1039/DF9715200140","url":null,"abstract":"A moderate surface reduction of TiO2(anatase or rutile) at 573–773 K under vacuum, or in the presence of carbon monoxide or hydrogen, or finally at room temperature under ultra-violet irradiation in vacuum or in the presence of hydrocarbons, creates two types of paramagnetic centres, which are identified by e.s.r. spectra as Ti3+ ions.Adsorption of oxygen (between 77 and 373 K) on TiO2 samples reduced in the ways described above leads to the formation of ionic species of the type O–2. The same species are also formed at room temperature on unreduced TiO2 samples submitted to an UV irradiation in the range of 2000–6000 A.These results are paralleled with the occurrence of photocatalytic (in u.-v.) partial oxidation of isobutane on TiO2 at room temperature.","PeriodicalId":11262,"journal":{"name":"Discussions of The Faraday Society","volume":"25 1","pages":"140-148"},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78243127","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 hole mobility in rubrene, in the c-direction, has been determined using time-of-flight measurements to be 2 cm2 V–1 s–1 at 473 K. The transport mechanism may be explained in terms of a band model with shallow trapping. No interpretable electron transport data were obtained.
{"title":"Hole mobility in rubrene","authors":"W. Williams","doi":"10.1039/DF9715100061","DOIUrl":"https://doi.org/10.1039/DF9715100061","url":null,"abstract":"The hole mobility in rubrene, in the c-direction, has been determined using time-of-flight measurements to be 2 cm2 V–1 s–1 at 473 K. The transport mechanism may be explained in terms of a band model with shallow trapping. No interpretable electron transport data were obtained.","PeriodicalId":11262,"journal":{"name":"Discussions of The Faraday Society","volume":"4 2 1","pages":"61-66"},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82839697","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}
Electrical and magnetic properties of poly(phenyleneaminochloranils, (PPhCh) obtained from different aromatic diamines (donors) and chloranil or quinone (acceptors) have been investigated. For each PPhCh, the current-voltage characteristics at different temperatures were recorded and Ea, σ293 and σ0 values were determined. Some of the (log10I,ƒ(1/T)), curves showed a kink and lead to two Ea values. For high temperatures the compensation law was fulfilled and a single value of the parameters α and β was calculated for all the PPhCh investigated. The characteristic temperature Tc does not correspond to the Tk value, nor do the Ea values correspond to the 1E1 value of the repeating unit. It is probable that the Ea values are modified by trap levels distributed throughout the sample. In support of this view, the dependence of Ea on voltage was investigated, and the trap density for unit energy was found. The magnetic properties, i.e., the susceptibility χ0 related to free carriers, depend on polymer structure. The χ0 values decrease with decrease of donor polarity and increase when the electron affinity of acceptors increases, thus enhancing the electrical conductivity.
研究了由不同芳香二胺(供体)和氯胺或醌(受体)合成的聚苯基氨基氯胺(PPhCh)的电、磁性质。记录了每一种PPhCh在不同温度下的电流-电压特性，测定了Ea、σ293和σ0值。一些(log10I, f (1/T))曲线显示出扭结并导致两个Ea值。在高温条件下，所有PPhCh均满足补偿规律，且α和β参数均为单一值。特征温度Tc不对应Tk值，Ea值也不对应重复单元的1E1值。很可能Ea值被分布在整个样品中的陷阱水平所改变。为了支持这一观点，研究了Ea对电压的依赖关系，并找到了单位能量的陷阱密度。磁性能，即与自由载流子相关的磁化率χ0，取决于聚合物的结构。χ0值随给体极性的减小而减小，随受体电子亲和力的增大而增大，从而提高了导电性能。
{"title":"Electrical and magnetic properties of poly(phenyleneaminochloranils)","authors":"M. Kryszewski, P. Wojciechowski, S. Sapieha","doi":"10.1039/DF9715100144","DOIUrl":"https://doi.org/10.1039/DF9715100144","url":null,"abstract":"Electrical and magnetic properties of poly(phenyleneaminochloranils, (PPhCh) obtained from different aromatic diamines (donors) and chloranil or quinone (acceptors) have been investigated. For each PPhCh, the current-voltage characteristics at different temperatures were recorded and Ea, σ293 and σ0 values were determined. Some of the (log10I,ƒ(1/T)), curves showed a kink and lead to two Ea values. For high temperatures the compensation law was fulfilled and a single value of the parameters α and β was calculated for all the PPhCh investigated. The characteristic temperature Tc does not correspond to the Tk value, nor do the Ea values correspond to the 1E1 value of the repeating unit. It is probable that the Ea values are modified by trap levels distributed throughout the sample. In support of this view, the dependence of Ea on voltage was investigated, and the trap density for unit energy was found. The magnetic properties, i.e., the susceptibility χ0 related to free carriers, depend on polymer structure. The χ0 values decrease with decrease of donor polarity and increase when the electron affinity of acceptors increases, thus enhancing the electrical conductivity.","PeriodicalId":11262,"journal":{"name":"Discussions of The Faraday Society","volume":"163 1","pages":"144-155"},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74798278","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}
A. Léonard, P. Ratnasamy, F. D. Declerck, J. J. Fripiat
In order to find to what extent the surface properties of amorphous silico-aluminas and aluminas are related to the atomic organization, the radial electron distribution and X-ray fluorescence spectroscopy were used to determine the kind of structure defects. For high-surface area solids (>100m2/g) a noticeable fraction of the cations and oxygen anions are in the first or the two first surface layers so that the averaged structure parameters obtained from these methods integrate the bulk and the surface organization. Assuming that the defects in the bulk and on the surface are comparable, it should be possible to correlate surface properties, such as the acid properties, with the nature of these defects. Moreover, if some quantitative agreements appear between e.g., the total number of defects and the number of surface acid sites of some sorts, the defects concentrations on the surface phase might be related to the total number of defects. The two above assumptions seem to be acceptable. The three main structure defects appear to be (i) the aluminium cations substituting silicon cations in tetrahedral coordination; (ii) aluminium cations in a perturbed tetrahedral arrangement and (iii) silicon in a perturbed tetrahedral arrangement. In these perturbed tetrahedral arrangements, one at least among the four oxygens might be displaced, exposing partially the cations to the outside. In aluminas, defects of type (ii) are the most probable; they are related to the Lewis acidity. In silico-aluminas, throughout the range of composition, 0 0.5, defects of type (iii) could provide a new source of Lewis acidity. These observations are supported by the variations in the catalytic cracking properties. Defects of type (ii) are also probable in the composition range 0.3 0.6. Also infra-red spectroscopic features of adsorbed NH3 seem to confirm these deductions.
{"title":"Structure and properties of amorphous silico-aluminas. Part 5.—Nature and properties of silico-alumina surfaces","authors":"A. Léonard, P. Ratnasamy, F. D. Declerck, J. J. Fripiat","doi":"10.1039/DF9715200098","DOIUrl":"https://doi.org/10.1039/DF9715200098","url":null,"abstract":"In order to find to what extent the surface properties of amorphous silico-aluminas and aluminas are related to the atomic organization, the radial electron distribution and X-ray fluorescence spectroscopy were used to determine the kind of structure defects. For high-surface area solids (>100m2/g) a noticeable fraction of the cations and oxygen anions are in the first or the two first surface layers so that the averaged structure parameters obtained from these methods integrate the bulk and the surface organization. Assuming that the defects in the bulk and on the surface are comparable, it should be possible to correlate surface properties, such as the acid properties, with the nature of these defects. Moreover, if some quantitative agreements appear between e.g., the total number of defects and the number of surface acid sites of some sorts, the defects concentrations on the surface phase might be related to the total number of defects. The two above assumptions seem to be acceptable. The three main structure defects appear to be (i) the aluminium cations substituting silicon cations in tetrahedral coordination; (ii) aluminium cations in a perturbed tetrahedral arrangement and (iii) silicon in a perturbed tetrahedral arrangement. In these perturbed tetrahedral arrangements, one at least among the four oxygens might be displaced, exposing partially the cations to the outside. In aluminas, defects of type (ii) are the most probable; they are related to the Lewis acidity. In silico-aluminas, throughout the range of composition, 0 0.5, defects of type (iii) could provide a new source of Lewis acidity. These observations are supported by the variations in the catalytic cracking properties. Defects of type (ii) are also probable in the composition range 0.3 0.6. Also infra-red spectroscopic features of adsorbed NH3 seem to confirm these deductions.","PeriodicalId":11262,"journal":{"name":"Discussions of The Faraday Society","volume":"100 1","pages":"98-108"},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74827946","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}
Ferric oxide hydrosols are composed of a haematite core surrounded by an hydrated oxide shell. Interactions have been studied, on both sides of the p.z.c., between ferric oxide surface and a series of anions and cations having characteristics ranging from structure promoters to structure breakers. Although ferric oxide has a moderate crystalline field, the observed adsorption sequences show that the interface acts as a structure promoter for water molecules. The large spreading of the measured adsorption sequences, especially at extreme pH values, proved the coagulation technique to be a good tool for the study of ion-surface interactions. A new type of behaviour has been observed; at low surface potentials the ions behave as indifferent but at higher surface potentials they are specifically adsorbed.
{"title":"Stability of ferric oxide hydrosols","authors":"F. Dumont, A. Watillon","doi":"10.1039/DF9715200352","DOIUrl":"https://doi.org/10.1039/DF9715200352","url":null,"abstract":"Ferric oxide hydrosols are composed of a haematite core surrounded by an hydrated oxide shell. Interactions have been studied, on both sides of the p.z.c., between ferric oxide surface and a series of anions and cations having characteristics ranging from structure promoters to structure breakers. Although ferric oxide has a moderate crystalline field, the observed adsorption sequences show that the interface acts as a structure promoter for water molecules. The large spreading of the measured adsorption sequences, especially at extreme pH values, proved the coagulation technique to be a good tool for the study of ion-surface interactions. A new type of behaviour has been observed; at low surface potentials the ions behave as indifferent but at higher surface potentials they are specifically adsorbed.","PeriodicalId":11262,"journal":{"name":"Discussions of The Faraday Society","volume":"271 1","pages":"352-360"},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81331898","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 energy band structures of coronene and ovalene have been calculated in the tight binding approximation using Slater-type orbitals for carbon. The energy band structures of both excess electrons and holes in coronene consist of two sets of energy bands, corresponding to the two degenerate molecular energy levels of the free molecule, which exhibit a high degree of anisotropy with an average width of 0.05 eV. The energy dependence on the wave vector for k parallel to b* has several unusual features. The behaviour can, however, be understood in terms of energy band-energy band interactions. Minimum values of the mobility, calculated such that the uncertainty principle is not violated, are ca. 5 cm2/V s along the b* axis. The energy band structure of ovalene is comparatively simple, again showing a high degree of anisotropy and large bandwidths (0.1 eV). Minimum values of the mobility are of a similar order to those in coronene.
{"title":"Calculation of the energy band structure and carrier mobilities in crystalline coronene and ovalene","authors":"H. Morris, J. Yates","doi":"10.1039/DF9715100024","DOIUrl":"https://doi.org/10.1039/DF9715100024","url":null,"abstract":"The energy band structures of coronene and ovalene have been calculated in the tight binding approximation using Slater-type orbitals for carbon. The energy band structures of both excess electrons and holes in coronene consist of two sets of energy bands, corresponding to the two degenerate molecular energy levels of the free molecule, which exhibit a high degree of anisotropy with an average width of 0.05 eV. The energy dependence on the wave vector for k parallel to b* has several unusual features. The behaviour can, however, be understood in terms of energy band-energy band interactions. Minimum values of the mobility, calculated such that the uncertainty principle is not violated, are ca. 5 cm2/V s along the b* axis. The energy band structure of ovalene is comparatively simple, again showing a high degree of anisotropy and large bandwidths (0.1 eV). Minimum values of the mobility are of a similar order to those in coronene.","PeriodicalId":11262,"journal":{"name":"Discussions of The Faraday Society","volume":"23 1","pages":"24-36"},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87148046","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}
A comparative study of the first-row transition metal ions Fe3+ and Mn2+ on the surfaces of aluminas and silicas has been made using the conventional techniques e.s.r., X-ray diffraction, magnetic susceptibility and in addition a relatively new technique phosphorescence spectroscopy.The results indicate that Fe3+ ions dissolve readily in γ-alumina up to 1 w% in samples calcined at 200°C and up to at least 10 % in samples calcined at 800°C. In silica not more than 0.1 w% Fe3+ could be dissolved, the remainder crystallizing as α-Fe2O3 on the surface. E.s.r. and phosphorescence indicate that Fe3+ ions on γ-Al2O3 calcined below 400°C are mostly octahedrally coordinated on the surface, but above this temperature the majority of the Fe3+ ions take up tetrahedral coordination. Mn2+ ions almost exclusively occupy tetrahedral holes at the surface. At the phase transition θ→α-Al2O3 above 1000°C, Fe3+ ions move into trigonally distorted octahedral sites whereas Mn2+ changes valence to Mn4+ in octahedral sites. Also in silica, Fe3+ ions preferentially take up tetrahedral coordination above 400°C heat treatments and remain in these sites up to 1200°C calcination temperatures.Most of these results can be explained on the basis of the differences between the structures of silicas and aluminas.
{"title":"Spectroscopic study of the coordination and valence of Fe and Mn ions in and on the surface of aluminas and silicas","authors":"G. T. Pott, B. D. Mcnicol","doi":"10.1039/DF9715200121","DOIUrl":"https://doi.org/10.1039/DF9715200121","url":null,"abstract":"A comparative study of the first-row transition metal ions Fe3+ and Mn2+ on the surfaces of aluminas and silicas has been made using the conventional techniques e.s.r., X-ray diffraction, magnetic susceptibility and in addition a relatively new technique phosphorescence spectroscopy.The results indicate that Fe3+ ions dissolve readily in γ-alumina up to 1 w% in samples calcined at 200°C and up to at least 10 % in samples calcined at 800°C. In silica not more than 0.1 w% Fe3+ could be dissolved, the remainder crystallizing as α-Fe2O3 on the surface. E.s.r. and phosphorescence indicate that Fe3+ ions on γ-Al2O3 calcined below 400°C are mostly octahedrally coordinated on the surface, but above this temperature the majority of the Fe3+ ions take up tetrahedral coordination. Mn2+ ions almost exclusively occupy tetrahedral holes at the surface. At the phase transition θ→α-Al2O3 above 1000°C, Fe3+ ions move into trigonally distorted octahedral sites whereas Mn2+ changes valence to Mn4+ in octahedral sites. Also in silica, Fe3+ ions preferentially take up tetrahedral coordination above 400°C heat treatments and remain in these sites up to 1200°C calcination temperatures.Most of these results can be explained on the basis of the differences between the structures of silicas and aluminas.","PeriodicalId":11262,"journal":{"name":"Discussions of The Faraday Society","volume":"1 1","pages":"121-131"},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88746389","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 effect of the geometrical structure and the chemistry of oxide surfaces on their adsorption properties","authors":"A. V. Kiselev","doi":"10.1039/DF9715200014","DOIUrl":"https://doi.org/10.1039/DF9715200014","url":null,"abstract":"","PeriodicalId":11262,"journal":{"name":"Discussions of The Faraday Society","volume":"24 1","pages":"14-32"},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78283143","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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