Shuyin Shen, Kai Liu, Hui-jun Xu, D. Gu, Fulong Tang, Qiying Chen
Phthalocyanine dyes with various central metal atoms and different substituents showing improved spectroscopic properties to match the output of GaAs diode-laser have been synthesized. Smooth thin films have been prepared by spin- coating technique. Solvent-vapor induced crystallization of VOPc(OC3H7)4 has also been studied. The results showed that the VOPc(OC3H7)4 primarily deposited on glass substrate as an amorphous form. However, the dyes were changed to crystalline form by exposure to appropriate solvent vapors. The polymorphs of the VOPc(OC3H7)4 were investigated by visible absorption and IR spectroscopy, X-ray diffraction and high resolution electron microscopy. The optical recording performances of the thin films were also reported.
{"title":"Spectroscopic properties of phthalocyanine dyes for optical recording medium","authors":"Shuyin Shen, Kai Liu, Hui-jun Xu, D. Gu, Fulong Tang, Qiying Chen","doi":"10.1117/12.248690","DOIUrl":"https://doi.org/10.1117/12.248690","url":null,"abstract":"Phthalocyanine dyes with various central metal atoms and different substituents showing improved spectroscopic properties to match the output of GaAs diode-laser have been synthesized. Smooth thin films have been prepared by spin- coating technique. Solvent-vapor induced crystallization of VOPc(OC3H7)4 has also been studied. The results showed that the VOPc(OC3H7)4 primarily deposited on glass substrate as an amorphous form. However, the dyes were changed to crystalline form by exposure to appropriate solvent vapors. The polymorphs of the VOPc(OC3H7)4 were investigated by visible absorption and IR spectroscopy, X-ray diffraction and high resolution electron microscopy. The optical recording performances of the thin films were also reported.","PeriodicalId":212484,"journal":{"name":"Optical Storage and Information Data Storage","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115721359","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. Gu, Qiying Chen, Xiaodong Tang, Fulong Tang, F. Gan, Shuyin Shen, Kai Liu, Hui-jun Xu
Optical recording performance of phthalocyanine thin films as write-once read-many recording media has ben investigated. The retrieval of information from the disk utilizing a phthalocyanine thin film has been successfully realized.
研究了酞菁薄膜作为一次写一次读多次记录介质的光学记录性能。利用酞菁薄膜成功地实现了磁盘信息的检索。
{"title":"Optical recording performance of phthalocyanine thin films","authors":"D. Gu, Qiying Chen, Xiaodong Tang, Fulong Tang, F. Gan, Shuyin Shen, Kai Liu, Hui-jun Xu","doi":"10.1117/12.248689","DOIUrl":"https://doi.org/10.1117/12.248689","url":null,"abstract":"Optical recording performance of phthalocyanine thin films as write-once read-many recording media has ben investigated. The retrieval of information from the disk utilizing a phthalocyanine thin film has been successfully realized.","PeriodicalId":212484,"journal":{"name":"Optical Storage and Information Data Storage","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126952859","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}
Recent research and development efforts in digital versatile disc mastering using dye-polymer media and direct-read- after-write technology are discussed. A comparison of this implementation to that of photoresist technology is given.
{"title":"Digital versatile disk mastering using dye-polymer media","authors":"J. Rilum","doi":"10.1117/12.248703","DOIUrl":"https://doi.org/10.1117/12.248703","url":null,"abstract":"Recent research and development efforts in digital versatile disc mastering using dye-polymer media and direct-read- after-write technology are discussed. A comparison of this implementation to that of photoresist technology is given.","PeriodicalId":212484,"journal":{"name":"Optical Storage and Information Data Storage","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128648415","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}
Several improvements to the optical disk drive and key parts have been carried out to enhance their function, storage density, capacity, data rate and reduce access time in recent years in the Optical Memory National Engineering Research Center (OMNERC). Approach for research on both of optical system and mechanic-electronic servo system are also reported in this paper. OMNERC of China started research and development on optical disk drive in the early 80's. In the past 15 years, many kinds of drives as phase-change erasable disk drive, CD-ROM drive, V-CD player etc. have been finished and some results of them have been playing important role in optical storage products manufacturing industry. In recent 5 years OMNERC has made the new optical drive model and some major technology research and development from the China national 8th five years science and technology development plan. The objective of this major subject is to make research and development on new generation multifunctional optical disk drive, especially on photo/thermo effect read, write and erase technology and drive as well as application systems. They are following projects: designing larger numerical aperture of objective lens used to enhance resolution and storage density, simplifying moving part of optical head to reduce its weight with holographic and other diffraction elements, increasing autofocusing and seeking precision, speed and proper frequency width of driving system, developing dual laser beams multifunctional optical head which is suitable for various inorganic and organic write once or erasable media, improving the data rate and reliability of storage data.
{"title":"Recent improvements to optical disk drive technology","authors":"Duanyi Xu, Z. Cai, Haichuan Zhang","doi":"10.1117/12.248702","DOIUrl":"https://doi.org/10.1117/12.248702","url":null,"abstract":"Several improvements to the optical disk drive and key parts have been carried out to enhance their function, storage density, capacity, data rate and reduce access time in recent years in the Optical Memory National Engineering Research Center (OMNERC). Approach for research on both of optical system and mechanic-electronic servo system are also reported in this paper. OMNERC of China started research and development on optical disk drive in the early 80's. In the past 15 years, many kinds of drives as phase-change erasable disk drive, CD-ROM drive, V-CD player etc. have been finished and some results of them have been playing important role in optical storage products manufacturing industry. In recent 5 years OMNERC has made the new optical drive model and some major technology research and development from the China national 8th five years science and technology development plan. The objective of this major subject is to make research and development on new generation multifunctional optical disk drive, especially on photo/thermo effect read, write and erase technology and drive as well as application systems. They are following projects: designing larger numerical aperture of objective lens used to enhance resolution and storage density, simplifying moving part of optical head to reduce its weight with holographic and other diffraction elements, increasing autofocusing and seeking precision, speed and proper frequency width of driving system, developing dual laser beams multifunctional optical head which is suitable for various inorganic and organic write once or erasable media, improving the data rate and reliability of storage data.","PeriodicalId":212484,"journal":{"name":"Optical Storage and Information Data Storage","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130936328","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}
This paper brings in focus the quality control issues during data handling in the CD production process. By warning for the problems that can occur at different points in the production chain, many costly, damaging and time-consuming errors can be prevented. Errors can happen anywhere along the line at various points and logistic interfaces. So it is important to identify what can go wrong from the authoring/pre-mastering stage all the way to shipping the final product to the customer.
{"title":"Quality control during data handling for mastering","authors":"Ruud Broers","doi":"10.1117/12.248706","DOIUrl":"https://doi.org/10.1117/12.248706","url":null,"abstract":"This paper brings in focus the quality control issues during data handling in the CD production process. By warning for the problems that can occur at different points in the production chain, many costly, damaging and time-consuming errors can be prevented. Errors can happen anywhere along the line at various points and logistic interfaces. So it is important to identify what can go wrong from the authoring/pre-mastering stage all the way to shipping the final product to the customer.","PeriodicalId":212484,"journal":{"name":"Optical Storage and Information Data Storage","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127404455","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 theory and experimental analysis has been made in this paper for the change of phase retardation in optical disk substrates when light beams pass through them from different incident angles. We tested the PC and glass substrate by using a polarization phase modulation method with Polarizer- Modulation-Compensator-Specimen-Analyzer structure.
{"title":"Measurement of stress birefringence in optical disk substrates","authors":"Xishan Li, Wendong Xu, Li Zhu","doi":"10.1117/12.248714","DOIUrl":"https://doi.org/10.1117/12.248714","url":null,"abstract":"The theory and experimental analysis has been made in this paper for the change of phase retardation in optical disk substrates when light beams pass through them from different incident angles. We tested the PC and glass substrate by using a polarization phase modulation method with Polarizer- Modulation-Compensator-Specimen-Analyzer structure.","PeriodicalId":212484,"journal":{"name":"Optical Storage and Information Data Storage","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116657786","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 enormous success of the CD-ROM has led to development of the CD-Recordable format and has resulted in a dramatic change in its market position. The CD-R media were introduced in the market place several years ago. The first media had stability problems. Since then, a series of improvements were developed, although incomplete, have resulted in the use of a wide variety of applications, in particular, CD-ROM editing. These applications favour higher data transfer speeds than that used for testing as defined in the Red Book. Recording higher than double the speed as defined in the Red Book creates both technological and compatibility problems. For that reason the CD-R standard, as described in the Orange Book, initially deals with single (lx) and double (2x)recording speeds.
{"title":"Manufacturing of CD-recordable discs","authors":"G. Ypma","doi":"10.1117/12.248687","DOIUrl":"https://doi.org/10.1117/12.248687","url":null,"abstract":"The enormous success of the CD-ROM has led to development of the CD-Recordable format and has resulted in a dramatic change in its market position. The CD-R media were introduced in the market place several years ago. The first media had stability problems. Since then, a series of improvements were developed, although incomplete, have resulted in the use of a wide variety of applications, in particular, CD-ROM editing. These applications favour higher data transfer speeds than that used for testing as defined in the Red Book. Recording higher than double the speed as defined in the Red Book creates both technological and compatibility problems. For that reason the CD-R standard, as described in the Orange Book, initially deals with single (lx) and double (2x)recording speeds.","PeriodicalId":212484,"journal":{"name":"Optical Storage and Information Data Storage","volume":"119 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116712820","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 great variety of reversible phase change optical recording materials have been extensively investigated. These alloy films are mainly composed of the IV-VI group (GeTe) and V group (Sb) in the periodic table. For achieving fast crystallization and stable cyclic operation, the excess Sb component of pseudo ternary alloy of GeTe-Sb2Te3-Sb has been investigated. At the melt-quenched process from the crystalline to the amorphous phase, the problem is to know if the laser pulse is essentially heating the sample which simply melts or if the electron-hole pairs created by the laser generate a new fluidlike state. The research on the electron-phonon interaction has shown that if a certain fraction of the valence-band electrons are excited into the conduction band, then the frequency of TA phonon, responsible for the stability of the crystal, goes to zero and crystal should become fluid. On the other hand, thin film surface becomes unstable before the bulk and the process of melting consists in the unstable surface at the film thickness of 10 - 50 nm. The inclusion of surface effects that self-consistently accounts for anharmonicity reduces the temperature at which an instability occurs. Both effects of electron-phonon instability and surface instability reduced the melting temperature of the phase change optical memory materials cooperatively. Therefore, the phase change optical disk is stable for the cyclic operation of 106 - 107.
{"title":"Size and electron hole pair effects on the melting of phase-change optical memory materials","authors":"M. Okuda, T. Matsushita","doi":"10.1117/12.248686","DOIUrl":"https://doi.org/10.1117/12.248686","url":null,"abstract":"A great variety of reversible phase change optical recording materials have been extensively investigated. These alloy films are mainly composed of the IV-VI group (GeTe) and V group (Sb) in the periodic table. For achieving fast crystallization and stable cyclic operation, the excess Sb component of pseudo ternary alloy of GeTe-Sb2Te3-Sb has been investigated. At the melt-quenched process from the crystalline to the amorphous phase, the problem is to know if the laser pulse is essentially heating the sample which simply melts or if the electron-hole pairs created by the laser generate a new fluidlike state. The research on the electron-phonon interaction has shown that if a certain fraction of the valence-band electrons are excited into the conduction band, then the frequency of TA phonon, responsible for the stability of the crystal, goes to zero and crystal should become fluid. On the other hand, thin film surface becomes unstable before the bulk and the process of melting consists in the unstable surface at the film thickness of 10 - 50 nm. The inclusion of surface effects that self-consistently accounts for anharmonicity reduces the temperature at which an instability occurs. Both effects of electron-phonon instability and surface instability reduced the melting temperature of the phase change optical memory materials cooperatively. Therefore, the phase change optical disk is stable for the cyclic operation of 106 - 107.","PeriodicalId":212484,"journal":{"name":"Optical Storage and Information Data Storage","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122872765","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}
Mastering refers to the process of forming the original pattern for replicating structures to provide the specified opto-electronic signals. Several technologies have been explored since the start of the optical storage industry. Mechanical cutting, as used in the conventional audio industry, turned out to be unpractical. Mastering dynamics could be best reached by laser beam recording. Literature reveals two types of possible processes for laser beam recording; photo-resist based and non-photoresist (ablative) based technology. The photo-resist technology is based upon a process using well established lithographic technologies. The master disc is composed of a glass substrate on which a layer of photo-resist material has been applied. The submicron sized portions of this photo-resist layer, exposed by the focused laser beam, give the requested opto-electronic structure after development and rinsing of the master substrate. The photo-resist based process is a microscopically localized process. The pit shape depends on the exposure of that area only and no contributions from adjacent spot positions are present. The photo-resist process has proven flexibility towards a large variety of groove and pit shapes. The final pit structure is controlled during the development process by pit-formation monitoring. Non photo-resist mastering deals with forming structures by local heating of specific areas of a substrate covered with an ablative material. The pit formation and the shape of the pit depend strongly on the temperature profile. This pit-formation process depends not only on the (heat) exposure of the laser beam for that given minute portion but also on the heat flow from neighbouring areas. If a nearby area has just been heated, heat will diffuse to that given area and cause a different pit shape. This highly unwanted phenomenon is known in optical recordable systems as "inter symbol interference". In order to prevent uncontrolled pit formation due to this interference from adjacent pits, complex write strategies have to be used. These write strategies are strongly dependent on recording speeds, layer thickness, spot quality and layer quality. In order to certify the performance of this process for its pit characteristics, the pit formation has to be verified by a second read beam. This read laser adds to the systems complexity while its reliability has to be certified systematically. This explains why more complex pit structures, e.q. MO, are preferably realized by the photoresist mastering process.
{"title":"Digital video disk mastering","authors":"J. M. Wijn, R. Alink","doi":"10.1117/12.248705","DOIUrl":"https://doi.org/10.1117/12.248705","url":null,"abstract":"Mastering refers to the process of forming the original pattern for replicating structures to provide the specified opto-electronic signals. Several technologies have been explored since the start of the optical storage industry. Mechanical cutting, as used in the conventional audio industry, turned out to be unpractical. Mastering dynamics could be best reached by laser beam recording. Literature reveals two types of possible processes for laser beam recording; photo-resist based and non-photoresist (ablative) based technology. The photo-resist technology is based upon a process using well established lithographic technologies. The master disc is composed of a glass substrate on which a layer of photo-resist material has been applied. The submicron sized portions of this photo-resist layer, exposed by the focused laser beam, give the requested opto-electronic structure after development and rinsing of the master substrate. The photo-resist based process is a microscopically localized process. The pit shape depends on the exposure of that area only and no contributions from adjacent spot positions are present. The photo-resist process has proven flexibility towards a large variety of groove and pit shapes. The final pit structure is controlled during the development process by pit-formation monitoring. Non photo-resist mastering deals with forming structures by local heating of specific areas of a substrate covered with an ablative material. The pit formation and the shape of the pit depend strongly on the temperature profile. This pit-formation process depends not only on the (heat) exposure of the laser beam for that given minute portion but also on the heat flow from neighbouring areas. If a nearby area has just been heated, heat will diffuse to that given area and cause a different pit shape. This highly unwanted phenomenon is known in optical recordable systems as \"inter symbol interference\". In order to prevent uncontrolled pit formation due to this interference from adjacent pits, complex write strategies have to be used. These write strategies are strongly dependent on recording speeds, layer thickness, spot quality and layer quality. In order to certify the performance of this process for its pit characteristics, the pit formation has to be verified by a second read beam. This read laser adds to the systems complexity while its reliability has to be certified systematically. This explains why more complex pit structures, e.q. MO, are preferably realized by the photoresist mastering process.","PeriodicalId":212484,"journal":{"name":"Optical Storage and Information Data Storage","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114852580","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}
CD-Audio is broadly seen as a success-story. For good reasons. The CD-Audio is a worldwide recognized standard; the underlying Red Book (1 982) its carefully and well protected by Philips and Sony. The industrial involvement of third parties is promoted by a non-discriminatory licensee policy. All this has led to an annual market volume of more than three billion discs involving a family of CD type application standards: CD-Audio, CD-ROM, CD-i, CD-R and CD-E. All these applications are based on the mechanical, opto-electronical, disc-layout and data encoding specifications described in the Red Book of 1 980. Since then a variety of technological improvements were developed leading to proposals for a new "Red Book". These trials were unsuccessful (for good reasons) until a broad consortium of companies went for a massive support towards the Digital Video Disc, DVD, standard. The DVD standard presents a challenging update of the Red Book for its technology as well as for its applications. Referring to the large variety of publications and press releases, the DVD product is certainly the most widely supported and most optimistically forecasted medium since the introduction of the CD. It happens that the optical industry has quite some experience with optimistically forecasts. These overestimations were partially attributable to inappropriate product positioning, to inadequate market volume assumptions and due to wrong assumptions on the time it would take to commercialize a new product. In looking back to this past and learning form the history of magnetic recording as well, we have to recognize that a variety of factors co-determine the success or failure in the market place. The purpose of this contribution is to evaluate the position of DVD. After summarizing the functionalities of the DVD standard, the growth factors will be summarized by evaluating the initial growth of the CD-Audio, the CD-ROM and the CD-R markets. Based on these experiences the prospects of the DVD will be discussed in terms of their most potential applications and their most relevant factors for their market growth.
{"title":"Prospects of DVD","authors":"J. Verhoeven","doi":"10.1117/12.248694","DOIUrl":"https://doi.org/10.1117/12.248694","url":null,"abstract":"CD-Audio is broadly seen as a success-story. For good reasons. The CD-Audio is a worldwide recognized standard; the underlying Red Book (1 982) its carefully and well protected by Philips and Sony. The industrial involvement of third parties is promoted by a non-discriminatory licensee policy. All this has led to an annual market volume of more than three billion discs involving a family of CD type application standards: CD-Audio, CD-ROM, CD-i, CD-R and CD-E. All these applications are based on the mechanical, opto-electronical, disc-layout and data encoding specifications described in the Red Book of 1 980. Since then a variety of technological improvements were developed leading to proposals for a new \"Red Book\". These trials were unsuccessful (for good reasons) until a broad consortium of companies went for a massive support towards the Digital Video Disc, DVD, standard. The DVD standard presents a challenging update of the Red Book for its technology as well as for its applications. Referring to the large variety of publications and press releases, the DVD product is certainly the most widely supported and most optimistically forecasted medium since the introduction of the CD. It happens that the optical industry has quite some experience with optimistically forecasts. These overestimations were partially attributable to inappropriate product positioning, to inadequate market volume assumptions and due to wrong assumptions on the time it would take to commercialize a new product. In looking back to this past and learning form the history of magnetic recording as well, we have to recognize that a variety of factors co-determine the success or failure in the market place. The purpose of this contribution is to evaluate the position of DVD. After summarizing the functionalities of the DVD standard, the growth factors will be summarized by evaluating the initial growth of the CD-Audio, the CD-ROM and the CD-R markets. Based on these experiences the prospects of the DVD will be discussed in terms of their most potential applications and their most relevant factors for their market growth.","PeriodicalId":212484,"journal":{"name":"Optical Storage and Information Data Storage","volume":"119 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116711450","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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