The phase equilibrium diagram for the binary system bismuth sesquioxide-niobium pentoxide has been constructed from observations of fusion characteristics and X-ray diffraction data. In the system five binary compounds were observed with Bi2O3:Nb2O5 ratios of 5:3, 1:1, 4:9, 1:5, and 1:6. The 1:1 compound was found to transform irreversibly (in laboratory time) from the orthorhombic bismutotantalite type structure to a triclinic form at about 1,020 °C and melt congruently at 1,245 °C. The 5:3 compound melts incongruently at 1,193 °C the 4:9 at 1,183 °C and the 1:6 at 1,242 °C. The 1:5 compound has a maximum temperature of stability at 1,095 °C and the 4:9 and 1:6 compounds have minimum temperatures of stability at 1,070 °C and 1,002 °C respectively. Nb2O5 was found to enter into solid solution in Bi2O3, up to about 23.5 mole percent Nb2O5. The melting point is increased and the monoclinic-cubic phase transformation temperature is decreased. A morphotropic phase change occurrs at about 19.5 mole percent Nb2O5 from the cubic to a pseudocubic structure.
{"title":"Phase Equilibrium Relations in the Binary System Bismuth Sesquioxide-Niobium Pentoxide","authors":"R. Roth, J. Waring","doi":"10.6028/jres.066A.046","DOIUrl":"https://doi.org/10.6028/jres.066A.046","url":null,"abstract":"The phase equilibrium diagram for the binary system bismuth sesquioxide-niobium pentoxide has been constructed from observations of fusion characteristics and X-ray diffraction data. In the system five binary compounds were observed with Bi2O3:Nb2O5 ratios of 5:3, 1:1, 4:9, 1:5, and 1:6. The 1:1 compound was found to transform irreversibly (in laboratory time) from the orthorhombic bismutotantalite type structure to a triclinic form at about 1,020 °C and melt congruently at 1,245 °C. The 5:3 compound melts incongruently at 1,193 °C the 4:9 at 1,183 °C and the 1:6 at 1,242 °C. The 1:5 compound has a maximum temperature of stability at 1,095 °C and the 4:9 and 1:6 compounds have minimum temperatures of stability at 1,070 °C and 1,002 °C respectively. Nb2O5 was found to enter into solid solution in Bi2O3, up to about 23.5 mole percent Nb2O5. The melting point is increased and the monoclinic-cubic phase transformation temperature is decreased. A morphotropic phase change occurrs at about 19.5 mole percent Nb2O5 from the cubic to a pseudocubic structure.","PeriodicalId":94340,"journal":{"name":"Journal of research of the National Bureau of Standards. Section A, Physics and chemistry","volume":"71 1","pages":"451 - 463"},"PeriodicalIF":0.0,"publicationDate":"1962-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90675249","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 surface pressure-area isotherms at 24.5 °C are reported for poly (ethylene adipate), poly(trimethylene adipate), and poly (propylene adipate), spread as monolayers at airaqueous interfaces. The monolayers were spread on distilled water and 0.01 N HC1, using benzene, chloroform, and acetone as spreading solvents. Poly (propylene adiptate) was the least compressible of the three, and poly (ethylene adipate) the most. Poly (propylene adipate) did not collapse at the highest pressure's studied. The spreading characteristics of both poly (ethylene adipate) and poly (propylene adipate) were independent of the amount of material used. The spreading of poly (trimethylene adipate) appeared to depend upon the spreading solvent. The effect of structure on the surface pressure—area isotherms and the specific areas for each polymer are discussed.
据报道，在24.5℃时，聚己二酸乙烯、聚己二酸三亚甲基和聚己二酸丙烯在空气-水界面上以单层形式分布。以苯、氯仿和丙酮为铺层溶剂，在蒸馏水和0.01 N HC1上铺层。聚己二酸丙烯的可压缩性最低，而聚己二酸乙烯的可压缩性最高。聚己二酸丙烯在研究的最高压力下未发生崩解。聚己二酸乙烯和聚己二酸丙烯的涂敷特性与材料用量无关。聚己二酸三亚甲基的涂覆似乎与涂覆溶剂有关。讨论了结构对各聚合物表面压力-面积等温线和比面积的影响。
{"title":"Monolayers of adipate polyesters at air-liquid interfaces","authors":"Wendell M. Lee, R. Stromberg, J. Shereshefsky","doi":"10.6028/JRES.066A.044","DOIUrl":"https://doi.org/10.6028/JRES.066A.044","url":null,"abstract":"The surface pressure-area isotherms at 24.5 °C are reported for poly (ethylene adipate), poly(trimethylene adipate), and poly (propylene adipate), spread as monolayers at airaqueous interfaces. The monolayers were spread on distilled water and 0.01 N HC1, using benzene, chloroform, and acetone as spreading solvents. Poly (propylene adiptate) was the least compressible of the three, and poly (ethylene adipate) the most. Poly (propylene adipate) did not collapse at the highest pressure's studied. The spreading characteristics of both poly (ethylene adipate) and poly (propylene adipate) were independent of the amount of material used. The spreading of poly (trimethylene adipate) appeared to depend upon the spreading solvent. The effect of structure on the surface pressure—area isotherms and the specific areas for each polymer are discussed.","PeriodicalId":94340,"journal":{"name":"Journal of research of the National Bureau of Standards. Section A, Physics and chemistry","volume":"32 1","pages":"439"},"PeriodicalIF":0.0,"publicationDate":"1962-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80728021","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}
An X-ray calorimeter has been used to determine the total energy transported by bremsstrahlung beams with maximum photon energies between 18.2 and 170 Mev. The measurements from two experiments have been used to calibrate an aluminum ionization chamber for routine determinations of total beam energy. The calibrations are compared with calibrations of the same chamber made with a scintillation spectrometer, and with calorimetric calibrations made in other laboratories.
{"title":"Calorimetric Calibration of an Ionization Chamber for Determination of X-ray Total Beam Energy*","authors":"J. S. Pruitt, S. Domen","doi":"10.6028/JRES.066A.038","DOIUrl":"https://doi.org/10.6028/JRES.066A.038","url":null,"abstract":"An X-ray calorimeter has been used to determine the total energy transported by bremsstrahlung beams with maximum photon energies between 18.2 and 170 Mev. The measurements from two experiments have been used to calibrate an aluminum ionization chamber for routine determinations of total beam energy. The calibrations are compared with calibrations of the same chamber made with a scintillation spectrometer, and with calorimetric calibrations made in other laboratories.","PeriodicalId":94340,"journal":{"name":"Journal of research of the National Bureau of Standards. Section A, Physics and chemistry","volume":"1 1","pages":"371"},"PeriodicalIF":0.0,"publicationDate":"1962-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77288959","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 Lorentz line shape formula is applied in the determination of half-width parameters due to foreign gas broadening. Various pressures of S0 2 and C0 2 are added to HCl and CO, respectively. The (1-0) and (2-0) HCl bands, as well as the (2-0) CO band, are investi gated, and there is found to be a very definite relationship between the half-width and the rotational quantum number, J. No error of more than 5 percent should be expected for the values of 7 0 presented. Some pressure-shifts are observed for HCl, but no quantitative determinations are made.
{"title":"Foreign Gas Broadening of the Lines of Hydrogen Chloride and Carbon Monoxide","authors":"E. K. Plyler, R. J. Thibault","doi":"10.6028/JRES.066A.043","DOIUrl":"https://doi.org/10.6028/JRES.066A.043","url":null,"abstract":"The Lorentz line shape formula is applied in the determination of half-width parameters due to foreign gas broadening. Various pressures of S0 2 and C0 2 are added to HCl and CO, respectively. The (1-0) and (2-0) HCl bands, as well as the (2-0) CO band, are investi gated, and there is found to be a very definite relationship between the half-width and the rotational quantum number, J. No error of more than 5 percent should be expected for the values of 7 0 presented. Some pressure-shifts are observed for HCl, but no quantitative determinations are made.","PeriodicalId":94340,"journal":{"name":"Journal of research of the National Bureau of Standards. Section A, Physics and chemistry","volume":"114 1","pages":"435"},"PeriodicalIF":0.0,"publicationDate":"1962-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80744837","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":"Pyrolysis of some polyvinyl polymers at temperatures up to 1,200 °C","authors":"S. Straus, S. L. Madorsky","doi":"10.6028/JRES.066A.041","DOIUrl":"https://doi.org/10.6028/JRES.066A.041","url":null,"abstract":"","PeriodicalId":94340,"journal":{"name":"Journal of research of the National Bureau of Standards. Section A, Physics and chemistry","volume":"70 1","pages":"401"},"PeriodicalIF":0.0,"publicationDate":"1962-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90374048","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}
Zinc oxide is the standard substance specified for calibrating the heat-of-solution calo rimeters used in determining the heat of hydration of portland cement in several American and foreign cement specifications. The heats of solution of zinc oxide samples from different sources and after different heat treatments have been determined in the standard mixture of nitric and hydrofluoric acids. It is concluded that the value given in the specifications is low, that heat treatment in the range 310 to 950 °C is not critical, that small variations in the ZnO/acid weight ratio are without significance, and that analytical-reagent zinc oxide from various sources may safely be used. The mean value obtained for the heats of solution of zinc oxide from twelve sources determined in triplicate in 1.00HNO 3,0.284HF,26.38H2O at a ZnO/acid weight ratio of 7/425 at 25 °C was 257.82 cal/g with a standard error of 0.015 cal/g. The thermochemical calorie of 4.1840 joules is used. The temperature coefficient based on least-square fitting to 16 data points obtained in an earlier study was —0.087 cal/g-deg, with a computed standard error of 0.013 cal/g-deg. The corresponding values for heat of solution and temperature coefficient given in the specifications are 256.6 cal/g and — 0.1 cal/g-deg, respectively.
{"title":"Zinc Oxide as a Standard Substance in the Solution Calorimetry of Portland Cement","authors":"E. Newman","doi":"10.6028/JRES.066A.039","DOIUrl":"https://doi.org/10.6028/JRES.066A.039","url":null,"abstract":"Zinc oxide is the standard substance specified for calibrating the heat-of-solution calo rimeters used in determining the heat of hydration of portland cement in several American and foreign cement specifications. The heats of solution of zinc oxide samples from different sources and after different heat treatments have been determined in the standard mixture of nitric and hydrofluoric acids. It is concluded that the value given in the specifications is low, that heat treatment in the range 310 to 950 °C is not critical, that small variations in the ZnO/acid weight ratio are without significance, and that analytical-reagent zinc oxide from various sources may safely be used. The mean value obtained for the heats of solution of zinc oxide from twelve sources determined in triplicate in 1.00HNO 3,0.284HF,26.38H2O at a ZnO/acid weight ratio of 7/425 at 25 °C was 257.82 cal/g with a standard error of 0.015 cal/g. The thermochemical calorie of 4.1840 joules is used. The temperature coefficient based on least-square fitting to 16 data points obtained in an earlier study was —0.087 cal/g-deg, with a computed standard error of 0.013 cal/g-deg. The corresponding values for heat of solution and temperature coefficient given in the specifications are 256.6 cal/g and — 0.1 cal/g-deg, respectively.","PeriodicalId":94340,"journal":{"name":"Journal of research of the National Bureau of Standards. Section A, Physics and chemistry","volume":"67 1","pages":"381"},"PeriodicalIF":0.0,"publicationDate":"1962-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73572741","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 nuclear optical model calculation of neutron elastic scattering using five parameters has been made. Appropriate estimates of the effect of compound elastic scattering at low energies are included. Comparisons have been made with experimental data, and results for the parameters adopted are given for elastic scattering in the energy range from 0.734 to 18 Mev. Although reasonably good agreement between the calculation and experimental results have been obtained, there is a discrepancy between experiments below 2 Mev, and experi mental data is needed between 6 and 14 Mev. Both angular distributions and Legendre expansion coefficients for the total elastic scattering are given.
{"title":"Nuclear Optical Model Analysis of Neutron Elastic Scattering for Calcium","authors":"R. S. Caswell","doi":"10.6028/JRES.066A.040","DOIUrl":"https://doi.org/10.6028/JRES.066A.040","url":null,"abstract":"A nuclear optical model calculation of neutron elastic scattering using five parameters has been made. Appropriate estimates of the effect of compound elastic scattering at low energies are included. Comparisons have been made with experimental data, and results for the parameters adopted are given for elastic scattering in the energy range from 0.734 to 18 Mev. Although reasonably good agreement between the calculation and experimental results have been obtained, there is a discrepancy between experiments below 2 Mev, and experi mental data is needed between 6 and 14 Mev. Both angular distributions and Legendre expansion coefficients for the total elastic scattering are given.","PeriodicalId":94340,"journal":{"name":"Journal of research of the National Bureau of Standards. Section A, Physics and chemistry","volume":"50 1","pages":"389"},"PeriodicalIF":0.0,"publicationDate":"1962-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81787493","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}
Infrared absorption spectra of inorganic nitrates and carbonates were obtained on single crystals at room temperature, under liquid nitrogen and liquid helium refrigeration. Diffuse absorption observed in the room temperature spectra between about 1400 and 700 cm/sup -1/ is solved under liquid helium refrigeration into a large number of bands not attributable to fundamentals or combinations of fundamental frequencies of the anions. Almost all of these bands are readily interpreted as summation bands of fundamental frequencies with successive levels of a librating oscillator. The libration is considered to represent a planar torsional oscillation of the anion about the trigonal axis. The librational frequency depends in part on the crystal structure and on the ions. In a given material the librational frequency as determined from successive bands is reasonably constant. In the substances studied the librational frequency varied from about 15 to 30 cm/sup -1/. Band limits observed in the spectra are interpreted as representing rotational energy barriers. These barrier heights are approximately 200 cm/sup -1/ with some dependence on the crystal structure and the ions involved. Barrier heights calculated from a cosine potential function agree reasonably well with the observed barriers for the cubic and calcite structures. Similar calculations weremore » not made for other structures studied because of doubtful assignments or unknown structural details. In particular, spectra of the aragonite structures are remarkable in detail and complexity, and were not analyzed. However, the details of these and all other spectra studied appear to involve similar phenomena. (auth)« less
{"title":"LATTICE FREQUENCIES AND ROTATIONAL BARRIERS FOR INORGANIC CARBONATES AND NITRATES FROM LOW TEMPERATURE INFRARED SPECTROSCOPY","authors":"R. Schroeder, C. Weir, E. Lippincott","doi":"10.6028/JRES.066A.042","DOIUrl":"https://doi.org/10.6028/JRES.066A.042","url":null,"abstract":"Infrared absorption spectra of inorganic nitrates and carbonates were obtained on single crystals at room temperature, under liquid nitrogen and liquid helium refrigeration. Diffuse absorption observed in the room temperature spectra between about 1400 and 700 cm/sup -1/ is solved under liquid helium refrigeration into a large number of bands not attributable to fundamentals or combinations of fundamental frequencies of the anions. Almost all of these bands are readily interpreted as summation bands of fundamental frequencies with successive levels of a librating oscillator. The libration is considered to represent a planar torsional oscillation of the anion about the trigonal axis. The librational frequency depends in part on the crystal structure and on the ions. In a given material the librational frequency as determined from successive bands is reasonably constant. In the substances studied the librational frequency varied from about 15 to 30 cm/sup -1/. Band limits observed in the spectra are interpreted as representing rotational energy barriers. These barrier heights are approximately 200 cm/sup -1/ with some dependence on the crystal structure and the ions involved. Barrier heights calculated from a cosine potential function agree reasonably well with the observed barriers for the cubic and calcite structures. Similar calculations weremore » not made for other structures studied because of doubtful assignments or unknown structural details. In particular, spectra of the aragonite structures are remarkable in detail and complexity, and were not analyzed. However, the details of these and all other spectra studied appear to involve similar phenomena. (auth)« less","PeriodicalId":94340,"journal":{"name":"Journal of research of the National Bureau of Standards. Section A, Physics and chemistry","volume":"56 1","pages":"407"},"PeriodicalIF":0.0,"publicationDate":"1962-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91227832","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. L. Madorsky, D. Mclntyre, J. H. O’Mara, S. Straus
In previous work on the thermal degradation of polystyrene of average molecular weight of 230,000, carried out in a vacuum in the temperature range 318 to 348 °C, the rate curves exhibited distinct maximums when percentage loss of sample per minute was plotted as a function of percentage volatilization. These maximums correspond to a volatilization of about 35 to 45 percent and tend to flatten with decreased temperature of pyrolysis. A similar study of rates of thermal degradation at 307.5 °C has now been made on two groups of polymers: (1) low molecular weight, 24,000; 51,000; and 66,000; and (2) high molecular weight, 2,000,000; 2,250,000; and 5,000,000. Whole polymers and also fractions of narrow-range molecular weight were used. The rate curves for the 24,000 and 51,000 molecular-weight samples exhibit very high initial rates, but no maximums; the 66,000 sample showed a maximum at 45 percent volatilization. The rate curves for the 2,000,000, 2,250,000, and 5,000,000 molecular-weight samples exhibit a gradual rise up to about 25 percent volatilization; then, instead of forming maximums, they follow plateaus to about 50 percent volatilization. These plateaus are indicative of a zero-order reaction in the range that they cover, and the rates corresponding to them fit well on the Arrhenius activation-energy curve obtained previously for polystyrene samples at higher temperatures.
{"title":"Thermal Degradation of Fractionated High and Low Molecular Weight Polystyrenes","authors":"S. L. Madorsky, D. Mclntyre, J. H. O’Mara, S. Straus","doi":"10.6028/jres.066A.029","DOIUrl":"https://doi.org/10.6028/jres.066A.029","url":null,"abstract":"In previous work on the thermal degradation of polystyrene of average molecular weight of 230,000, carried out in a vacuum in the temperature range 318 to 348 °C, the rate curves exhibited distinct maximums when percentage loss of sample per minute was plotted as a function of percentage volatilization. These maximums correspond to a volatilization of about 35 to 45 percent and tend to flatten with decreased temperature of pyrolysis. A similar study of rates of thermal degradation at 307.5 °C has now been made on two groups of polymers: (1) low molecular weight, 24,000; 51,000; and 66,000; and (2) high molecular weight, 2,000,000; 2,250,000; and 5,000,000. Whole polymers and also fractions of narrow-range molecular weight were used. The rate curves for the 24,000 and 51,000 molecular-weight samples exhibit very high initial rates, but no maximums; the 66,000 sample showed a maximum at 45 percent volatilization. The rate curves for the 2,000,000, 2,250,000, and 5,000,000 molecular-weight samples exhibit a gradual rise up to about 25 percent volatilization; then, instead of forming maximums, they follow plateaus to about 50 percent volatilization. These plateaus are indicative of a zero-order reaction in the range that they cover, and the rates corresponding to them fit well on the Arrhenius activation-energy curve obtained previously for polystyrene samples at higher temperatures.","PeriodicalId":94340,"journal":{"name":"Journal of research of the National Bureau of Standards. Section A, Physics and chemistry","volume":"62 5 1","pages":"307 - 311"},"PeriodicalIF":0.0,"publicationDate":"1962-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89818661","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}
Relaxation spectra have been used in both the presentation and interpretation of measurements of the mechanical properties of rubberlike polymers.
弛豫谱已被用于描述和解释类橡胶聚合物的力学性能测量。
{"title":"Derivation of the Relaxation Spectrum Representation of the Mechanical Response Function","authors":"R. Marvin","doi":"10.6028/JRES.066A.036","DOIUrl":"https://doi.org/10.6028/JRES.066A.036","url":null,"abstract":"Relaxation spectra have been used in both the presentation and interpretation of measurements of the mechanical properties of rubberlike polymers.","PeriodicalId":94340,"journal":{"name":"Journal of research of the National Bureau of Standards. Section A, Physics and chemistry","volume":"52 1","pages":"349 - 350"},"PeriodicalIF":0.0,"publicationDate":"1962-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85723642","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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