Pub Date : 2015-06-01DOI: 10.1515/umcschem-2015-0001
M. Hierro-Oliva, A. M. Gallardo-Moreno, A. Rodríguez-Cano, J. Bruque, M. Gónzalez-Martín
Abstract In the biomedical field, water contact angle is a useful gauge to follow how a biomaterial surface would interact with the surrounding water-like physiological environment. Ti6Al4V alloy is widely used in orthopedic applications. Nevertheless, the values of its water contact angle reported in the literature show a large dispersion, from 40° up 80°. However, in addition to the expected dependence of the surface wettability on preliminary treatments, the values of the water contact angle on the pristine Ti6Al4V alloy suffers from an important variability and lack of reproducibility. The present research pays attention to this difficulty and proposes a simple experimental procedure to ensure adequate contact angle reproducibility. Controlled passivation growth in mild underwater conditions of freshly polished disks, followed by ultrasonic washing, avoiding the rubbing of the surface, gives average water contact angles of 80° with very low standard deviations also among samples from the same batch.
{"title":"Experimental approach towards the water contact angle value on the biomaterial alloy Ti6Al4V","authors":"M. Hierro-Oliva, A. M. Gallardo-Moreno, A. Rodríguez-Cano, J. Bruque, M. Gónzalez-Martín","doi":"10.1515/umcschem-2015-0001","DOIUrl":"https://doi.org/10.1515/umcschem-2015-0001","url":null,"abstract":"Abstract In the biomedical field, water contact angle is a useful gauge to follow how a biomaterial surface would interact with the surrounding water-like physiological environment. Ti6Al4V alloy is widely used in orthopedic applications. Nevertheless, the values of its water contact angle reported in the literature show a large dispersion, from 40° up 80°. However, in addition to the expected dependence of the surface wettability on preliminary treatments, the values of the water contact angle on the pristine Ti6Al4V alloy suffers from an important variability and lack of reproducibility. The present research pays attention to this difficulty and proposes a simple experimental procedure to ensure adequate contact angle reproducibility. Controlled passivation growth in mild underwater conditions of freshly polished disks, followed by ultrasonic washing, avoiding the rubbing of the surface, gives average water contact angles of 80° with very low standard deviations also among samples from the same batch.","PeriodicalId":7937,"journal":{"name":"Annales UMCS, Chemia","volume":"429 1","pages":"1 - 13"},"PeriodicalIF":0.0,"publicationDate":"2015-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76635887","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}
Pub Date : 2015-06-01DOI: 10.1515/umcschem-2015-0009
K. Terpiłowski
Abstract Wettability of solids is a key phenomenon in many processes. One should mentioned those which accompany us in our everyday life i.e. washing or cementing as well as those applied in industry e.g. flotation of minerals. Value of the contact angles are affected by many factors. One of them is temperature. In this paper monocrystaline quartz was used in the investigations which were carried out in the range 5−50°C with the step every 5°C. As follows the value of the contact angle of both water and diiodomethane changes with the increasing temperature. The change of its value for water is much larger than in case of another liquids of apolar character. Using Chibowski approach the apparent surface free energy was calculated in two ways with and without correction about temperature change of the surface tension. The calculation show difference between both results. Taking into consideration another value of the surface tension should not be neglected even if measurements is taken at a temperature close to 20°C which is the standard in one in such measurements
{"title":"Influence of the ambient temperature on water and diiodomethane contact angle with quartz surface","authors":"K. Terpiłowski","doi":"10.1515/umcschem-2015-0009","DOIUrl":"https://doi.org/10.1515/umcschem-2015-0009","url":null,"abstract":"Abstract Wettability of solids is a key phenomenon in many processes. One should mentioned those which accompany us in our everyday life i.e. washing or cementing as well as those applied in industry e.g. flotation of minerals. Value of the contact angles are affected by many factors. One of them is temperature. In this paper monocrystaline quartz was used in the investigations which were carried out in the range 5−50°C with the step every 5°C. As follows the value of the contact angle of both water and diiodomethane changes with the increasing temperature. The change of its value for water is much larger than in case of another liquids of apolar character. Using Chibowski approach the apparent surface free energy was calculated in two ways with and without correction about temperature change of the surface tension. The calculation show difference between both results. Taking into consideration another value of the surface tension should not be neglected even if measurements is taken at a temperature close to 20°C which is the standard in one in such measurements","PeriodicalId":7937,"journal":{"name":"Annales UMCS, Chemia","volume":"1 1","pages":"125 - 136"},"PeriodicalIF":0.0,"publicationDate":"2015-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89755995","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}
Pub Date : 2014-12-01DOI: 10.2478/umcschem-2013-0014
G. Thirunarayanan
Abstract A series containing ten aryl 3-(substituted phenyl) bicyclo [2.2.1] heptene-2-yl-methanone derivatives including 3- (substituted phenyl) bicyclo [2.2.1]hepten-2-yl-(pyren-1-yl)- methanones have been synthesized by aqueous phase fly-ash catalyzed [4+2] Diels-Alder cyclo addition reaction of cyclopentadiene and aryl chalcones. The yields of the methanones are more than 60%. The synthesized methanones are characterized by their physical constants and spectral data. The insect antifeedant activities of synthesized methanones have been studied using Dethler’s leaf-discs bioassay method.
{"title":"Aqueous phase fly-ash catalyzed [4+2] Diels-Alder reaction of aryl enones and cyclopentadiene: Synthesis and insect antifeedant activities of aryl bicyclo [2.2.1] heptene-2-yl-methanones","authors":"G. Thirunarayanan","doi":"10.2478/umcschem-2013-0014","DOIUrl":"https://doi.org/10.2478/umcschem-2013-0014","url":null,"abstract":"Abstract A series containing ten aryl 3-(substituted phenyl) bicyclo [2.2.1] heptene-2-yl-methanone derivatives including 3- (substituted phenyl) bicyclo [2.2.1]hepten-2-yl-(pyren-1-yl)- methanones have been synthesized by aqueous phase fly-ash catalyzed [4+2] Diels-Alder cyclo addition reaction of cyclopentadiene and aryl chalcones. The yields of the methanones are more than 60%. The synthesized methanones are characterized by their physical constants and spectral data. The insect antifeedant activities of synthesized methanones have been studied using Dethler’s leaf-discs bioassay method.","PeriodicalId":7937,"journal":{"name":"Annales UMCS, Chemia","volume":"61 1","pages":"127 - 140"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91235418","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}
Pub Date : 2014-12-01DOI: 10.2478/umcschem-2013-0016
P. Mayavel, K. Thirumurthy, S. Dineshkumar, G. Thirunarayanana
Abstract A series of Schiff’s bases (aryl E-imines) have been derived from the perchloric acid catalyzed condensation of aryl amines and substituted benzaldehydes. The yield of the Schiff’s bases are more than 80%. The synthesized Schiff’s bases are characterized by their physical constants, analytical and spectroscopical data. The antibacterial activities of these Schiff’s bases have been studied using Bauer-Kirby method.
{"title":"Perchloric acid catalyzed condensation of amine and aldehydes: Synthesis and antibacterial activities of some aryl (E)-imines","authors":"P. Mayavel, K. Thirumurthy, S. Dineshkumar, G. Thirunarayanana","doi":"10.2478/umcschem-2013-0016","DOIUrl":"https://doi.org/10.2478/umcschem-2013-0016","url":null,"abstract":"Abstract A series of Schiff’s bases (aryl E-imines) have been derived from the perchloric acid catalyzed condensation of aryl amines and substituted benzaldehydes. The yield of the Schiff’s bases are more than 80%. The synthesized Schiff’s bases are characterized by their physical constants, analytical and spectroscopical data. The antibacterial activities of these Schiff’s bases have been studied using Bauer-Kirby method.","PeriodicalId":7937,"journal":{"name":"Annales UMCS, Chemia","volume":"1 1","pages":"159 - 179"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79848834","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}
Pub Date : 2014-12-01DOI: 10.2478/umcschem-2013-0015
G. Thirunarayanan
Abstract Some 4-aryl-5,6-dihydro-6-(substituted phenyl)-4H-1,3-oxazine- 2-amine derivatives including 4-(4-methyl-1-naphthyl)-5,6- dihydro-6-(substituted phenyl)-4H-1,3-oxazine-2-amines have been synthesised by hydroxyapatite catalyzed solvent-free cyclization of aryl chalcones and urea using microwave irradiation under solventfree condition. The yields of the oxazines were more than 85%. The synthesised oxazine amines have been characterized by their physical constants, analytical and spectroscopic data.
{"title":"Hydroxyapatite catalyzed cyclization of aryl enones: Solvent-free efficient synthesis of some 4-aryl-5,6-dihydro- 6-(substituted phenyl)-4H-1,3-oxazine-2-amines","authors":"G. Thirunarayanan","doi":"10.2478/umcschem-2013-0015","DOIUrl":"https://doi.org/10.2478/umcschem-2013-0015","url":null,"abstract":"Abstract Some 4-aryl-5,6-dihydro-6-(substituted phenyl)-4H-1,3-oxazine- 2-amine derivatives including 4-(4-methyl-1-naphthyl)-5,6- dihydro-6-(substituted phenyl)-4H-1,3-oxazine-2-amines have been synthesised by hydroxyapatite catalyzed solvent-free cyclization of aryl chalcones and urea using microwave irradiation under solventfree condition. The yields of the oxazines were more than 85%. The synthesised oxazine amines have been characterized by their physical constants, analytical and spectroscopic data.","PeriodicalId":7937,"journal":{"name":"Annales UMCS, Chemia","volume":"1 1","pages":"141 - 158"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75487060","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}
Pub Date : 2014-12-01DOI: 10.2478/umcschem-2013-0013
Z. Rzączyńska, Anna Danczowska-Burdona, M. Drewniak
Abstract The lanthanide(III) complexes with 2,3-pyridinedicarboxylate ligand (PDC) were obtained as crystalline compounds from the water solutions. These compounds form the series of Ln2(PDC)3 ・ nH2O. All compounds are stable in air and insoluble in both water and common organic solvents. The hydrated complexes have been characterized by elemental analysis, thermal analysis (TG/DSC/DTA, and TG−FT-IR), FT-IR spectroscopy and X-ray analysis. 2,3-pyridinedicarboxylates of lanthanides(III) are stable in air below 313−323 K. Upon heating, hydrated complexes lose crystallization and lattice water in two steps. The values of dehydration enthalpy complexes are calculated from the DSC curves. The anhydrous compounds are stable at the temperature from 473 K to about 623 K and when heated they decompose to lanthanide oxides. Thermal and spectroscopic studies are essential for further studies and classification of compounds as MOF-like structures.
{"title":"Thermal behaviour of light lanthanide(III) complexes with 2,3-pyridinedicarboxylic acid","authors":"Z. Rzączyńska, Anna Danczowska-Burdona, M. Drewniak","doi":"10.2478/umcschem-2013-0013","DOIUrl":"https://doi.org/10.2478/umcschem-2013-0013","url":null,"abstract":"Abstract The lanthanide(III) complexes with 2,3-pyridinedicarboxylate ligand (PDC) were obtained as crystalline compounds from the water solutions. These compounds form the series of Ln2(PDC)3 ・ nH2O. All compounds are stable in air and insoluble in both water and common organic solvents. The hydrated complexes have been characterized by elemental analysis, thermal analysis (TG/DSC/DTA, and TG−FT-IR), FT-IR spectroscopy and X-ray analysis. 2,3-pyridinedicarboxylates of lanthanides(III) are stable in air below 313−323 K. Upon heating, hydrated complexes lose crystallization and lattice water in two steps. The values of dehydration enthalpy complexes are calculated from the DSC curves. The anhydrous compounds are stable at the temperature from 473 K to about 623 K and when heated they decompose to lanthanide oxides. Thermal and spectroscopic studies are essential for further studies and classification of compounds as MOF-like structures.","PeriodicalId":7937,"journal":{"name":"Annales UMCS, Chemia","volume":"18 1","pages":"111 - 126"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89389918","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}
Pub Date : 2014-10-17DOI: 10.2478/umcschem-2013-0010
D. Rymuszka, K. Terpiłowski, L. Hołysz
Abstract The aim of the research was to determine how the drop size affects the contact angle values and determine its optimal size for further contact angle measurements and comparison of the contact angle values measured for three probe liquids (water, formamide, diiodomethane) on the glass surface using the: sessile drop and tilting plate methods. Next, using the measured contact angles, the total surface free energy and its components were determined from the van Oss et al. (Lifshitz-van der Waals acid- base component, LWAB), Owens-Wendt, Neumann and contact angle hysteresis (CAH) approaches. The studies showed, that drop size is very important for contact angle measurements and consequently, for surface free energy estimation.
摘要:本研究的目的是确定液滴大小如何影响接触角值，并确定其最佳尺寸，以进一步测量接触角，并比较使用固定式液滴和倾斜板方法在玻璃表面上测量的三种探针液体(水、甲酰胺、二碘甲烷)的接触角值。接下来，利用测量的接触角，通过van Oss等人(Lifshitz-van der Waals酸碱组分，LWAB)、Owens-Wendt、Neumann和接触角迟滞(CAH)方法确定总表面自由能及其组成。研究表明，液滴大小对接触角的测量和表面自由能的估计非常重要。
{"title":"Influence of Volume Drop on Surface Free Energy of Glass","authors":"D. Rymuszka, K. Terpiłowski, L. Hołysz","doi":"10.2478/umcschem-2013-0010","DOIUrl":"https://doi.org/10.2478/umcschem-2013-0010","url":null,"abstract":"Abstract The aim of the research was to determine how the drop size affects the contact angle values and determine its optimal size for further contact angle measurements and comparison of the contact angle values measured for three probe liquids (water, formamide, diiodomethane) on the glass surface using the: sessile drop and tilting plate methods. Next, using the measured contact angles, the total surface free energy and its components were determined from the van Oss et al. (Lifshitz-van der Waals acid- base component, LWAB), Owens-Wendt, Neumann and contact angle hysteresis (CAH) approaches. The studies showed, that drop size is very important for contact angle measurements and consequently, for surface free energy estimation.","PeriodicalId":7937,"journal":{"name":"Annales UMCS, Chemia","volume":"14 1","pages":"121 - 132"},"PeriodicalIF":0.0,"publicationDate":"2014-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85131704","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}
Pub Date : 2014-10-17DOI: 10.2478/umcschem-2013-0004
Mateusz Lutomski, B. Gawdzik
Abstract Optical cables and fibers are extremely sensitive for mechanical, thermal and environmental conditions, which can affect their optical performance. This article describes known reasons and mechanisms responsible for dimensional changes in temperatures cycling, which can influence optical and mechanical performance and properties of the cables, including internal cable components. Understanding all physical and chemical mechanisms which meet different manufacturing parameters, various materials properties and external conditions allows to control and reduction of cable shrinking and as a result, improving mechanical and optical performance of optical cables.
{"title":"Polymer Dimensional Changes in Optical Cables","authors":"Mateusz Lutomski, B. Gawdzik","doi":"10.2478/umcschem-2013-0004","DOIUrl":"https://doi.org/10.2478/umcschem-2013-0004","url":null,"abstract":"Abstract Optical cables and fibers are extremely sensitive for mechanical, thermal and environmental conditions, which can affect their optical performance. This article describes known reasons and mechanisms responsible for dimensional changes in temperatures cycling, which can influence optical and mechanical performance and properties of the cables, including internal cable components. Understanding all physical and chemical mechanisms which meet different manufacturing parameters, various materials properties and external conditions allows to control and reduction of cable shrinking and as a result, improving mechanical and optical performance of optical cables.","PeriodicalId":7937,"journal":{"name":"Annales UMCS, Chemia","volume":"91 1","pages":"33 - 49"},"PeriodicalIF":0.0,"publicationDate":"2014-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85223698","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}
Pub Date : 2014-10-17DOI: 10.2478/umcschem-2013-0011
A. Woszczyk, P. Szabelski
Abstract The influence of external factors on the chiral resolution of enantiomers in adsorbed overlayes has been especially interesting form the perspective of creation of chiral surfaces. Chiral segregation of this type can be induced or enhanced, for example, by an external unidirectional fields such as magnetic or electric field. To explore the effect of an external field on the 2D chiral resolution of model enentiomers we performed cannonical Monte Carlo simulations on a square lattice of equivalent adsorption sites. The adsorbed molecules which are sensitive to the external field, were assumed to consist of four identical segments and they were able to adopt four possible orientations on a square lattice. Shortrange segment-segment interactions limited to the nearest neighbours on the lattice were allowed to account for the intermolecular interactions. The calculations were performed for two exemplary molecular structures and the strength of the external field was gradually increased in each case. The preliminary results described herein demonstrate that continuously changed external fields can induce chiral resolution of enantiomers of appropriate geometry. The insights from this study can be useful in developing strategies for 2D chiral separations in which external stimuli are used.
{"title":"Enhancing the Separation of Enantiomers in Adsorbed Overlayers: A Monte Carlo Study","authors":"A. Woszczyk, P. Szabelski","doi":"10.2478/umcschem-2013-0011","DOIUrl":"https://doi.org/10.2478/umcschem-2013-0011","url":null,"abstract":"Abstract The influence of external factors on the chiral resolution of enantiomers in adsorbed overlayes has been especially interesting form the perspective of creation of chiral surfaces. Chiral segregation of this type can be induced or enhanced, for example, by an external unidirectional fields such as magnetic or electric field. To explore the effect of an external field on the 2D chiral resolution of model enentiomers we performed cannonical Monte Carlo simulations on a square lattice of equivalent adsorption sites. The adsorbed molecules which are sensitive to the external field, were assumed to consist of four identical segments and they were able to adopt four possible orientations on a square lattice. Shortrange segment-segment interactions limited to the nearest neighbours on the lattice were allowed to account for the intermolecular interactions. The calculations were performed for two exemplary molecular structures and the strength of the external field was gradually increased in each case. The preliminary results described herein demonstrate that continuously changed external fields can induce chiral resolution of enantiomers of appropriate geometry. The insights from this study can be useful in developing strategies for 2D chiral separations in which external stimuli are used.","PeriodicalId":7937,"journal":{"name":"Annales UMCS, Chemia","volume":"43 1","pages":"133 - 141"},"PeriodicalIF":0.0,"publicationDate":"2014-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73303101","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}
Pub Date : 2014-10-17DOI: 10.2478/umcschem-2013-0006
D. Myśliwiec, Stanisław Chibowsk
Abstract Experimental adsorption data were analysed by fitting them to nonlinear forms of Langmuir and Freundlich isotherms. Optimization of the parameters was performed by nonlinear least square regression with different forms of error function, namely: vertical, horizontal, orthogonal, normal and squared normal. The results showed, that isotherm parameters may be affected by the selection of error function and that they are more sensitive to its’ form in case of Langmuir equation. We did not find any correlation between a type of the function and performance of the regression – procedure requires optimization for every experimental dataset and every model being fitted.
{"title":"Statistical Analysis of Adsorption Experimental Data – the Influence of the Selection of Error Function on Optimized Isotherm Parameters","authors":"D. Myśliwiec, Stanisław Chibowsk","doi":"10.2478/umcschem-2013-0006","DOIUrl":"https://doi.org/10.2478/umcschem-2013-0006","url":null,"abstract":"Abstract Experimental adsorption data were analysed by fitting them to nonlinear forms of Langmuir and Freundlich isotherms. Optimization of the parameters was performed by nonlinear least square regression with different forms of error function, namely: vertical, horizontal, orthogonal, normal and squared normal. The results showed, that isotherm parameters may be affected by the selection of error function and that they are more sensitive to its’ form in case of Langmuir equation. We did not find any correlation between a type of the function and performance of the regression – procedure requires optimization for every experimental dataset and every model being fitted.","PeriodicalId":7937,"journal":{"name":"Annales UMCS, Chemia","volume":"11 1","pages":"63 - 73"},"PeriodicalIF":0.0,"publicationDate":"2014-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75223267","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：