Inzwischen ist es nicht mehr zu ignorieren: das Konzept der Mensch-Maschine-Interaktion steht vor erheblichen Veränderungen. Das Interface, wie wir es kennen, geht seinem Ende entgegen und damit ist nicht der Umstieg auf die nächste Generation Touchdisplay gemeint. Wir alle wissen, dass Fahrer von Landmaschinen viel zu häufig überfordert sind. Trotz erfolgreicher Bewältigung dieses Knochenjobs fällt die Wertschätzung eher gering aus, auch nach einem 14-Stunden-Tag. Infolgedessen findet die ganze Branche kaum noch Nachwuchs für einen der spannendsten Arbeitsplätze in einer Landwirtschaft, die sich immer weiter digitalisiert.
{"title":"Usability Engineering: Die Zukunft der Mensch-Maschine-Interaktion in der Landtechnik","authors":"Jens Krzywinski","doi":"10.15150/LT.2017.3175","DOIUrl":"https://doi.org/10.15150/LT.2017.3175","url":null,"abstract":"Inzwischen ist es nicht mehr zu ignorieren: das Konzept der Mensch-Maschine-Interaktion steht vor erheblichen Veränderungen. Das Interface, wie wir es kennen, geht seinem Ende entgegen und damit ist nicht der Umstieg auf die nächste Generation Touchdisplay gemeint. Wir alle wissen, dass Fahrer von Landmaschinen viel zu häufig überfordert sind. Trotz erfolgreicher Bewältigung dieses Knochenjobs fällt die Wertschätzung eher gering aus, auch nach einem 14-Stunden-Tag. Infolgedessen findet die ganze Branche kaum noch Nachwuchs für einen der spannendsten Arbeitsplätze in einer Landwirtschaft, die sich immer weiter digitalisiert.","PeriodicalId":35524,"journal":{"name":"Landtechnik","volume":"72 1","pages":"305–307-305–307"},"PeriodicalIF":0.0,"publicationDate":"2018-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44534105","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}
Florian Mader, Alexander J. Schmithausen, Manfred Trimborn, S. Hoppe, Wolfgang Büscher
In modern dairy cow housing systems, the animals’ cubicles are mostly scattered with organic materials, which have a positive effect on the lying behaviour of the cows and the hygiene in the cubicles. The objective of the present study was to investigate the economic and climate-relevant qualities of different bedding materials in the cubicles. The bedding materials showed differences in the acceptance among the animals as well as in the effort and expense involved. A further focus was on climatically relevant gases emitted by the bedding materials and their emission potential. Emissions in the cubicles were low compared to further emission sources in the barn (CH 4 from ruminal digestion and manure storage) or emissions (N 2 O) generated during and after the spreading of slurry on the field. The measured emissions of the applied bedding materials are even negligibly low if the applied organic materials are scattered throughout the entire cubicles in the barn.
{"title":"Bewertung von Einstreumaterialien für Liegeboxen in der Milchviehhaltung","authors":"Florian Mader, Alexander J. Schmithausen, Manfred Trimborn, S. Hoppe, Wolfgang Büscher","doi":"10.15150/LT.2017.3174","DOIUrl":"https://doi.org/10.15150/LT.2017.3174","url":null,"abstract":"In modern dairy cow housing systems, the animals’ cubicles are mostly scattered with organic materials, which have a positive effect on the lying behaviour of the cows and the hygiene in the cubicles. The objective of the present study was to investigate the economic and climate-relevant qualities of different bedding materials in the cubicles. The bedding materials showed differences in the acceptance among the animals as well as in the effort and expense involved. A further focus was on climatically relevant gases emitted by the bedding materials and their emission potential. Emissions in the cubicles were low compared to further emission sources in the barn (CH 4 from ruminal digestion and manure storage) or emissions (N 2 O) generated during and after the spreading of slurry on the field. The measured emissions of the applied bedding materials are even negligibly low if the applied organic materials are scattered throughout the entire cubicles in the barn.","PeriodicalId":35524,"journal":{"name":"Landtechnik","volume":"72 1","pages":"293–304-293–304"},"PeriodicalIF":0.0,"publicationDate":"2017-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41732966","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 Hohenheim Tyre Model was developed for investigations regarding driving dynamics as well as driving comfort. Before its application as development tool, it has to be thoroughly validated. Regarding vertical and lateral investigations, the model is validated by comparing simulation results with measurements on single tyres and on whole vehicles. A single wheel tester and an equipped test tractor are used to determine the forces acting between the tyre and the road surface as well as the driving conditions during certain manoeuvres. The conducted road tests are reproduced using multi-body simulation models (MBS) simulation models in connection with the Hohenheim Tyre Model. By using separate evaluation metrics regarding the magnitude and phase behaviour, a good correlation between measurements and simulation results is shown.
{"title":"Quantifizierte Validierung des Hohenheimer Reifenmodells für fahrdynamische Untersuchungen","authors":"A. Bürger, S. Böttinger","doi":"10.15150/lt.2017.3173","DOIUrl":"https://doi.org/10.15150/lt.2017.3173","url":null,"abstract":"The Hohenheim Tyre Model was developed for investigations regarding driving dynamics as well as driving comfort. Before its application as development tool, it has to be thoroughly validated. Regarding vertical and lateral investigations, the model is validated by comparing simulation results with measurements on single tyres and on whole vehicles. A single wheel tester and an equipped test tractor are used to determine the forces acting between the tyre and the road surface as well as the driving conditions during certain manoeuvres. The conducted road tests are reproduced using multi-body simulation models (MBS) simulation models in connection with the Hohenheim Tyre Model. By using separate evaluation metrics regarding the magnitude and phase behaviour, a good correlation between measurements and simulation results is shown.","PeriodicalId":35524,"journal":{"name":"Landtechnik","volume":"72 1","pages":"280–292-280–292"},"PeriodicalIF":0.0,"publicationDate":"2017-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43818223","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}
To increase the throughput of the cleaning unit in a combine harvester, an improvement of the separation process and thus an optimization of the mechanic and aerodynamic excitations is necessary. One opportunity to improve the functioning of the cleaning unit is to optimize the sieve movement. For this purpose, the cleaning unit test rig of the Institute of Agricultural Engineering was extended with a drive system that enables the investigation of linear, circular and elliptical sieve movements. The evaluation of the conducted investigations allows an assessment of the functioning of the cleaning unit. Parallel conducted Discrete-Element-simulations in combination with Computational-Fluid-Dynamics-simulations (DEM-CFD-simulations) allow the investigation of the particle movement of grain and material other than grain (MOG) and therefore a more detailed analysis of the processes.
{"title":"Einfluss elliptischer Siebbewegungen auf die Arbeitsweise der Mähdrescherreinigungsanlage","authors":"Konstantin Beckmann, J. Pförtner, S. Böttinger","doi":"10.15150/lt.2017.3171","DOIUrl":"https://doi.org/10.15150/lt.2017.3171","url":null,"abstract":"To increase the throughput of the cleaning unit in a combine harvester, an improvement of the separation process and thus an optimization of the mechanic and aerodynamic excitations is necessary. One opportunity to improve the functioning of the cleaning unit is to optimize the sieve movement. For this purpose, the cleaning unit test rig of the Institute of Agricultural Engineering was extended with a drive system that enables the investigation of linear, circular and elliptical sieve movements. The evaluation of the conducted investigations allows an assessment of the functioning of the cleaning unit. Parallel conducted Discrete-Element-simulations in combination with Computational-Fluid-Dynamics-simulations (DEM-CFD-simulations) allow the investigation of the particle movement of grain and material other than grain (MOG) and therefore a more detailed analysis of the processes.","PeriodicalId":35524,"journal":{"name":"Landtechnik","volume":"72 1","pages":"266–279-266–279"},"PeriodicalIF":0.0,"publicationDate":"2017-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49320997","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}
Der Einsatz von thermischen Unkrautbekampfungsverfahren in Reihenkulturen ist wegen einer unzureichenden Prazision derzeit nicht fur die selektive Unkrautkontrolle geeignet. Abflamm-, Heiswasser-, Heisdampf- oder Heisschaumgerate haben aufgrund ihrer breitflachigen Wirkweise den Nachteil, dass sie – um Schaden zu vermeiden – einen relativ grosen Sicherheitsabstand zur Kulturpflanze benotigen. Die Spritzapplikation von heisen, pflanzlichen Olen aus nachwachsenden Rohstoffen soll neben einer hohen Prazision bei der Ausbringung auch eine effektive und umweltfreundliche Bekampfung von Unkrautern sogar im Intra-row-Bereich ermoglichen. Am Institut fur Landtechnik der Universitat Bonn wurde ein Prototyp eines Applikationssystems entwickelt, mit dessen Hilfe umfangreiche Laborversuche durchgefuhrt werden konnen, um die Schadwirkung von heisen Pflanzenolen an verschiedenen Ackerunkrautern zu erforschen.
{"title":"Entwicklung eines Applikationssystems zur selektiven, thermischen Unkrautbekämpfung in Reihenkulturen mit Pflanzenöl","authors":"Jürgen Peukert, P. Lammers, L. Damerow","doi":"10.15150/LT.2017.3165","DOIUrl":"https://doi.org/10.15150/LT.2017.3165","url":null,"abstract":"Der Einsatz von thermischen Unkrautbekampfungsverfahren in Reihenkulturen ist wegen einer unzureichenden Prazision derzeit nicht fur die selektive Unkrautkontrolle geeignet. Abflamm-, Heiswasser-, Heisdampf- oder Heisschaumgerate haben aufgrund ihrer breitflachigen Wirkweise den Nachteil, dass sie – um Schaden zu vermeiden – einen relativ grosen Sicherheitsabstand zur Kulturpflanze benotigen. Die Spritzapplikation von heisen, pflanzlichen Olen aus nachwachsenden Rohstoffen soll neben einer hohen Prazision bei der Ausbringung auch eine effektive und umweltfreundliche Bekampfung von Unkrautern sogar im Intra-row-Bereich ermoglichen. Am Institut fur Landtechnik der Universitat Bonn wurde ein Prototyp eines Applikationssystems entwickelt, mit dessen Hilfe umfangreiche Laborversuche durchgefuhrt werden konnen, um die Schadwirkung von heisen Pflanzenolen an verschiedenen Ackerunkrautern zu erforschen.","PeriodicalId":35524,"journal":{"name":"Landtechnik","volume":"72 1","pages":"202–213-202–213"},"PeriodicalIF":0.0,"publicationDate":"2017-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42302116","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}
Rita Zapf, U. Schultheiß, U. Knierim, J. Brinkmann, L. Schrader
Nach dem Tierschutzgesetz ist seit 2014 eine „betriebliche Eigenkontrolle“ hinsichtlich des Tierwohls vorgeschrieben. Nutztierhalter sollen geeignete tierbezogene Merkmale zur Beurteilung der Tiergerechtheit im Stall erheben und bewerten. Da das Tierschutzgesetz jedoch keine Verordnungsermachtigung mit Ausfuhrungsbestimmungen zum Inhalt und Umfang der Eigenkontrolle enthalt, besteht in der Praxis noch immer ein groser Handlungsbedarf. Unter Federfuhrung des KTBL wurden in Fachgesprachen mit Experten Indikatoren zur Bewertung der Tiergerechtheit ausgewahlt, mit denen die wichtigsten aus der Praxis bekannten Tierschutzprobleme festgestellt werden konnen. Die hierbei fur Rinder-, Schweine- sowie Huhner- und Putenhaltung vorgeschlagenen, uberwiegend tierbezogenen Indikatoren wurden 2016 als anschauliche Anleitung fur Nutztierhalter zur Verfugung gestellt. Die vorliegende Arbeit diskutiert den Nutzen einer betrieblichen Eigenkontrolle und stellt die Leitfaden fur die Praxis vor.
{"title":"Tierwohl messen im Nutztierbestand – Leitfäden für die betriebliche Eigenkontrolle","authors":"Rita Zapf, U. Schultheiß, U. Knierim, J. Brinkmann, L. Schrader","doi":"10.15150/LT.2017.3166","DOIUrl":"https://doi.org/10.15150/LT.2017.3166","url":null,"abstract":"Nach dem Tierschutzgesetz ist seit 2014 eine „betriebliche Eigenkontrolle“ hinsichtlich des Tierwohls vorgeschrieben. Nutztierhalter sollen geeignete tierbezogene Merkmale zur Beurteilung der Tiergerechtheit im Stall erheben und bewerten. Da das Tierschutzgesetz jedoch keine Verordnungsermachtigung mit Ausfuhrungsbestimmungen zum Inhalt und Umfang der Eigenkontrolle enthalt, besteht in der Praxis noch immer ein groser Handlungsbedarf. Unter Federfuhrung des KTBL wurden in Fachgesprachen mit Experten Indikatoren zur Bewertung der Tiergerechtheit ausgewahlt, mit denen die wichtigsten aus der Praxis bekannten Tierschutzprobleme festgestellt werden konnen. Die hierbei fur Rinder-, Schweine- sowie Huhner- und Putenhaltung vorgeschlagenen, uberwiegend tierbezogenen Indikatoren wurden 2016 als anschauliche Anleitung fur Nutztierhalter zur Verfugung gestellt. Die vorliegende Arbeit diskutiert den Nutzen einer betrieblichen Eigenkontrolle und stellt die Leitfaden fur die Praxis vor.","PeriodicalId":35524,"journal":{"name":"Landtechnik","volume":"72 1","pages":"214–222-214–222"},"PeriodicalIF":0.0,"publicationDate":"2017-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46766710","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":"Weitreichende Änderungen bei der Düngegesetzgebung","authors":"U. Schultheiß","doi":"10.15150/lt.2017.3164","DOIUrl":"https://doi.org/10.15150/lt.2017.3164","url":null,"abstract":"","PeriodicalId":35524,"journal":{"name":"Landtechnik","volume":"72 1","pages":"176–178-176–178"},"PeriodicalIF":0.0,"publicationDate":"2017-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43534148","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}
Korbinian Nachtmann, S. Baum, Máté Fuchsz, Oliver Falk, J. Hofmann
A new treatment concept is intended to make biogas plants more flexible and energy-efficient and to show new marketing possibilities. This is made possible by an innovative low-temperature liquefaction unit, which separates the carbon dioxide portion as dry ice and liquefies the energetic methane at normal pressure. In the laboratory scale, the principle has been successfully implemented and optimised: An adapted multi-stage gas purification, which also works in the absence of oxygen, completely eliminates the fraction of hydrogen sulphide and other contaminants by means of iron preparations and activated carbon filters. By means of clever process control and material selection in the multi-stage heat exchanger system, the carbon dioxide can be separated as snow, thus establishing a continuous process. The resulting dry ice can be sold both energetically and materially as a by-product of gas treatment. In the final liquefaction step, in addition to an energy density of approximately 6.44 kWh per litre of liquid biomethane (based on the calorific value Hs), methane purities of up to 99.9% vol. can be achieved depending on the application case.
{"title":"Effiziente Speicherung und mobile Nutzung von Biogas als flüssiges Biomethan","authors":"Korbinian Nachtmann, S. Baum, Máté Fuchsz, Oliver Falk, J. Hofmann","doi":"10.15150/LT.2017.3163","DOIUrl":"https://doi.org/10.15150/LT.2017.3163","url":null,"abstract":"A new treatment concept is intended to make biogas plants more flexible and energy-efficient and to show new marketing possibilities. This is made possible by an innovative low-temperature liquefaction unit, which separates the carbon dioxide portion as dry ice and liquefies the energetic methane at normal pressure. In the laboratory scale, the principle has been successfully implemented and optimised: An adapted multi-stage gas purification, which also works in the absence of oxygen, completely eliminates the fraction of hydrogen sulphide and other contaminants by means of iron preparations and activated carbon filters. By means of clever process control and material selection in the multi-stage heat exchanger system, the carbon dioxide can be separated as snow, thus establishing a continuous process. The resulting dry ice can be sold both energetically and materially as a by-product of gas treatment. In the final liquefaction step, in addition to an energy density of approximately 6.44 kWh per litre of liquid biomethane (based on the calorific value Hs), methane purities of up to 99.9% vol. can be achieved depending on the application case.","PeriodicalId":35524,"journal":{"name":"Landtechnik","volume":"72 1","pages":"179–201-179–201"},"PeriodicalIF":0.0,"publicationDate":"2017-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42629826","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}
Nora Hammer, M. Pfeifer, Max Staiger, Felix Adrion, Eva Gallmann, T. Jungbluth
Increasing legal requirements regarding animal welfare on livestock production units that are simultaneously increasing in size require an optimisation of housing conditions with high demands on the management of such farms. Within an innovation project, a UHF-RFID system for simultaneous detection and monitoring of fattening pigs and dairy cows at particular hotspots within the respective housing environments was developed in order to simplify management of farms with larger numbers of livestock. Following many technical advances, there still remains lack of clarity regarding opportunities for UHF systems on the market. To help clarify matters, a cost-benefit analysis was carried out based on four fictive example farms (2 x fattening pigs and 2 x dairy cattle). The results show that the UHF-RFID system applied under the assumptions made offered an economic advantage under the best possible conditions for only one of the dairy farms. Rentability of the system for the other farms could only be achieved if an enormous cost reduction was assumed.
{"title":"Kosten-Nutzen-Analyse eines UHF-RFID-Systems zur Tierkennzeichnung, Simultanerfassung und Hotspotüberwachung von Mastschweinen und Milchkühen","authors":"Nora Hammer, M. Pfeifer, Max Staiger, Felix Adrion, Eva Gallmann, T. Jungbluth","doi":"10.15150/LT.2017.3160","DOIUrl":"https://doi.org/10.15150/LT.2017.3160","url":null,"abstract":"Increasing legal requirements regarding animal welfare on livestock production units that are simultaneously increasing in size require an optimisation of housing conditions with high demands on the management of such farms. Within an innovation project, a UHF-RFID system for simultaneous detection and monitoring of fattening pigs and dairy cows at particular hotspots within the respective housing environments was developed in order to simplify management of farms with larger numbers of livestock. Following many technical advances, there still remains lack of clarity regarding opportunities for UHF systems on the market. To help clarify matters, a cost-benefit analysis was carried out based on four fictive example farms (2 x fattening pigs and 2 x dairy cattle). The results show that the UHF-RFID system applied under the assumptions made offered an economic advantage under the best possible conditions for only one of the dairy farms. Rentability of the system for the other farms could only be achieved if an enormous cost reduction was assumed.","PeriodicalId":35524,"journal":{"name":"Landtechnik","volume":"72 1","pages":"130–156-130–156"},"PeriodicalIF":0.0,"publicationDate":"2017-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47640012","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}
In search of economically and ecologically interesting alternatives and additions to maize, currently the predominantly used biogas substrate, cup plant (Silphium perfoliatum L.) has been found as a promising plant species. The perennial composite, which is located in North America, can be established by modified conventional seeders. Due to a long flowering period and different geographic origins of the plant material, seeds of different sizes and shapes can be found in the seed batch, which makes a precise singling of the seeds difficult. For the quantification of the geometric parameters the seeds were recorded and measured. The results of these researches were used to optimize the seeding in precision seeders.
{"title":"Bestimmung der Korngeometrie der Durchwachsenen Silphie als Voraussetzung für die Einzelkornsaat","authors":"A. Schäfer, L. Damerow, P. Lammers","doi":"10.15150/LT.2017.3159","DOIUrl":"https://doi.org/10.15150/LT.2017.3159","url":null,"abstract":"In search of economically and ecologically interesting alternatives and additions to maize, currently the predominantly used biogas substrate, cup plant (Silphium perfoliatum L.) has been found as a promising plant species. The perennial composite, which is located in North America, can be established by modified conventional seeders. Due to a long flowering period and different geographic origins of the plant material, seeds of different sizes and shapes can be found in the seed batch, which makes a precise singling of the seeds difficult. For the quantification of the geometric parameters the seeds were recorded and measured. The results of these researches were used to optimize the seeding in precision seeders.","PeriodicalId":35524,"journal":{"name":"Landtechnik","volume":"72 1","pages":"122–129-122–129"},"PeriodicalIF":0.0,"publicationDate":"2017-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45040246","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：