Automotive and Engine Technology最新文献

{"title":"Performance of pure OME and various HVO–OME fuel blends as alternative fuels for a diesel engine","authors":"Alexander Holzer,&nbsp;Michael Günthner,&nbsp;Philipp Jung","doi":"10.1007/s41104-022-00122-8","DOIUrl":"10.1007/s41104-022-00122-8","url":null,"abstract":"<div><p>Since the potential for reducing CO₂ emissions from fossil fuels is limited, suitable CO₂-neutral fuels are required for applications which cannot reasonably be electrified, and therefore still rely on internal combustion engines in the future. Potential fuel candidates for CI engines are either paraffinic diesel fuels or new fuels like POMDME (polyoxymethylene dimethyl ether, short “OME”). Besides, also blends of these two types of fuels might be of interest. While many studies have been conducted on OME blends with fossil diesel fuel, the research on HVO–OME blends has been less extensive to date.</p><p>In the current work, pure OME and HVO–OME blends are investigated in a single-cylinder research engine. The test results of the various fuel blend formulations are compared and evaluated, particularly with regard to soot-NO_x trade-off behavior. The primary objective of the study is to examine whether the major potential of blending these two fuels is already largely exploited at low OME content, or if significant additional emission reduction potential can still be found with higher content blends, but still without the need to switch to pure OME operation. Furthermore, the fuel blend which is best suited for the realization of an ultra-low emission concept under the current technical conditions should be identified. In addition, three different injector designs were tested for operation on pure OME3-5, differing both in hydraulic flow and in the number of injection holes as well as their layout. The optimum configuration is evaluated with regard to emissions, normalized heat release and indicated efficiency.</p></div>","PeriodicalId":100150,"journal":{"name":"Automotive and Engine Technology","volume":"7 3-4","pages":"369 - 383"},"PeriodicalIF":0.0,"publicationDate":"2022-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s41104-022-00122-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50500414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modelling of the NOx storage behaviour during cold start of modern zeolite SCR catalysts","authors":"Deinhofer Lukas,&nbsp;Maurer Michael,&nbsp;Barnstedt Gert,&nbsp;Keber Andreas","doi":"10.1007/s41104-022-00119-3","DOIUrl":"10.1007/s41104-022-00119-3","url":null,"abstract":"<div><p>Further stringent emission regulations of modern diesel engines call for a more precise prediction of NO_x emissions, thus enabling a better control of the exhaust-gas aftertreatment systems. A major part of the NO_x emissions is emitted before the light-off temperature of the selective catalytic reduction (SCR) catalyst is reached. Therefore a precise emissions prediction is necessary during the cold start phase of a diesel passenger car. Recent measurements show that NO_x emissions can be stored in the SCR catalysts during cold start. Furthermore a part of this stored NO_x can be reduced during the driving cycle.</p><p>This paper describes an empiric model predicting the NO_x storage behaviour during vehicle cold start. In a previous work the main influence parameters on the NO_x storage behaviour were investigated on a synthetic gas test bench. The knowledge gained from the previous research work defines the necessary input parameters for the NO_x storage model. These investigations showed that the NO_x storage effect strongly depends on the ammonia (NH₃-) level stored in the catalyst, exhaust-gas mass flow, the water adsorbed (H₂O) on the catalyst, and the temperature of the catalyst. The model was implemented for on-filter and flow-through SCR catalysts. There are two similar models, one for the close-coupled SCR system and the other one for the underfloor SCR system. Each NO_x storage model is split into an adsorption part and a desorption part. For both parts the pre-conditioning from the previous driving cycle is taken into account, which means that the catalyst state at the end of the last driving cycle initializes the model data for the current cycle, in consideration of the downtime between the two cycles. The desorption part calculates the NO_x conversion amount and defines the desorption mass flow of NO_x resulting from the NO_x storage effect. The developed NO_x storage model has been validated with roller dynamometer measurements and with real world driving cycles.</p></div>","PeriodicalId":100150,"journal":{"name":"Automotive and Engine Technology","volume":"7 3-4","pages":"353 - 368"},"PeriodicalIF":0.0,"publicationDate":"2022-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s41104-022-00119-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50509131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Passengers comfort during automated motorway lane changes: a subject study on different lane change trajectories at the Stuttgart driving simulator","authors":"Christoph Heimsath,&nbsp;Werner Krantz,&nbsp;Jens Neubeck,&nbsp;Christian Holzapfel,&nbsp;Andreas Wagner","doi":"10.1007/s41104-022-00118-4","DOIUrl":"10.1007/s41104-022-00118-4","url":null,"abstract":"<div><p>This article presents the setup and results of a recent subject study at the full-scale moving Stuttgart driving simulator. The study focusses on the passenger’s comfort during automated lane changes in a high-speed two-lane motorway scenario. The scenario contains different symmetric and asymmetric lane change trajectories, bends and road surface qualities. Each asymmetric trajectory is divided into two parts with different characteristics. The subjects input their subjective impression of comfort directly after each lane change on a tablet computer. The phase in which the vehicle leaves its previous lane and the phase in which the vehicle arrives at its target lane are rated individually. This enables a detailed effect analysis for the two characteristic parts of asymmetric lane change trajectory shapes. The evaluation method is able to determine subjective differences even at small objective changes. Result analysis verifies correlations between objective criteria describing the trajectory characteristics and the subjective comfort ratings. In addition, a curvature caused bias on the subjective ratings in bends is determined. The results motivate the curvature-dependent use of asymmetric lane change trajectories to improve comfort without reducing longitudinal velocity or increase lane change duration and thus maintaining traffic efficiency in terms of required traffic interspaces to cut in. The study data is further used for the development of a passengers’ comfort metric for automated driving functions.</p></div>","PeriodicalId":100150,"journal":{"name":"Automotive and Engine Technology","volume":"7 3-4","pages":"343 - 351"},"PeriodicalIF":0.0,"publicationDate":"2022-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s41104-022-00118-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50455096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Potentials of oxymethylene-dimethyl-ether in diesel engine combustion","authors":"Christopher Saupe,&nbsp;Frank Atzler","doi":"10.1007/s41104-022-00117-5","DOIUrl":"10.1007/s41104-022-00117-5","url":null,"abstract":"<div><p>The increasing CO₂ concentration in the atmosphere and the resulting climate change require an immediate and efficient reduction of anthropogenic carbon-dioxide emission. This target can be achieved by the usage of CO₂-neutral fuels even with current technologies (Schemme et al. in Int J Hydrogen Energy 45:5395–5414, 2020). Diesel engines in particular are amongst the most efficient prime movers. Using oxymethylene-dimethyl-ether (OME) it is possible to solve the hitherto existing Soot-NO_<i>x</i>-Trade-off. OME has bounded oxygen in the molecular chain. This reduces the formation of soot, but equally the calorific value. But in considerance of the physical and chemical properties of OME, it could be useful to optimize the standard diesel engine into an OME engine. As a result, single-cylinder tests were performed to obtain a detailed analysis of the differences between OME3-5 and commercially available DIN EN 590 Diesel. Based on the fact that OME has gravimetrically less than half the calorific value of diesel, twice the fuel mass must be injected for the same energy release in the combustion chamber. Therefore, at the beginning of the investigations, a variation of the injector flow rate was carried out by means of different nozzle hole diameters. The evaluation of the results included the fundamental differences in the combustion characteristics of both fuels and the determination of efficiency-increasing potentials in the conversion of OME3-5. Due to the lower ignition delay and the shorter combustion time of OME, potentials in the optimisation of the injection setting became apparent. Higher energy flows over the combustion chamber wall were noticeable in operation with OME. To get to the bottom of this, the single-cylinder investigations were supported by tests on the optically accessible high-pressure chamber and the single-cylinder transparent engine. The optical images showed a narrower cone angle and greater penetration depth of the OME injection jet compared to the diesel injection jet. This confirmed the results from the single-cylinder tests. This provides further potential in the design of the injector nozzle to compensate for these deficits. Overall, this work shows that operation with OME in a classic diesel engine is possible without any significant loss in efficiency and with little effort in the hardware. However, it is also possible to achieve more efficient use of the synthetic fuel with minor adjustments.</p></div>","PeriodicalId":100150,"journal":{"name":"Automotive and Engine Technology","volume":"7 3-4","pages":"331 - 342"},"PeriodicalIF":0.0,"publicationDate":"2022-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s41104-022-00117-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50443129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"AI-based classification of CAN measurements for network and ECU identification","authors":"Ralf Lutchen,&nbsp;Andreas Krätschmer,&nbsp;Hans Christian Reuss","doi":"10.1007/s41104-022-00116-6","DOIUrl":"10.1007/s41104-022-00116-6","url":null,"abstract":"<div><p>Due to the constantly increasing number of functions offered by a modern vehicle, the complexity of vehicle development is also increasing as a result. A first indication of this connection is provided by the number of ECUs (electronic control units) used in current development vehicles. Furthermore, each ECU also performs more functions and is not only electrically networked with the other ECUs, but also logically and functionally. On this basis, new cooperative functions are being developed, which are used for example for autonomous driving. In vehicle development, more and more test sequences (diagnostic scripts) are established for function testing of individual components, systems and cross-functional methods. Due to decentralization and the modular approach, modern development vehicles consist of different numbers of ECUs. The high number of ECUs in purpose and number poses a challenge for test creation and updating. The ECU software is also developed in cycles within the vehicle cycle. This results in a very high software variance. This variance leads to the fact that in the vehicle development with global test conditions works. Global test conditions at this point mean that more ECUs are included in the measurement procedure than are installed in the vehicle. The vehicle structure (control unit and its software version) is not known to the person performing the measurement. He relies on the fact that his ECUs are inside in the global measurement task. This means that the vehicle network architecture is uncertain, which can lead to errors during test execution. Since the ECUs that are actually installed in the vehicle are first determined during test execution, this results in a longer script runtime than would be necessary. To support the development engineer and prevent avoidable errors, the diagnostic system should configure itself as far as possible. This means that individually customized measurements for each vehicle should be calculated in the cloud and not the global measurement tasks. For a diagnostic system to be able to configure itself independently, the vehicle network structure must be determined in a first step. This can be done by a simple CAN measurement (measurementXY.asc). An AI is able to analyze this measurement and classify the occurring ECUs as well as CAN networks. For larger measuring devices with more than one CAN interface, the user who analyzes the measurement is interested in which CAN was connected. Here, the AI is suitable to determine the name of the network and the communicating ECUs based on the communication that runs over the bus. For this purpose, the AI classifies the number of communicating ECUs based on the time intervals at which messages are sent. In addition, the AI can be supported by a special diagnostic script (global.pattern) to determine the vehicle structure at the OBD (on-board diagnostics) interface with maximum accuracy. Three AI approaches are presented, all connected in series a","PeriodicalId":100150,"journal":{"name":"Automotive and Engine Technology","volume":"7 3-4","pages":"317 - 330"},"PeriodicalIF":0.0,"publicationDate":"2022-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s41104-022-00116-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50515023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Smart data preprocessing method for remote vehicle diagnostics to increase data compression efficiency","authors":"Lorenz Görne,&nbsp;Hans-Christian Reuss,&nbsp;Andreas Krätschmer,&nbsp;Ralf Sauerwald","doi":"10.1007/s41104-022-00113-9","DOIUrl":"10.1007/s41104-022-00113-9","url":null,"abstract":"<div><p>The increasing number of functions in modern vehicle leads to an exponential increase in software complexity. The validity and reliability of all components must be ensured, making the use of appropriate vehicle diagnostics systems indispensable. The purpose of such systems is to collect and process data about the vehicle. To find issues during vehicle development, the OEMs will usually have a development fleet of thousands of vehicles. The challenge for diagnostic systems is to detect issues during these tests, as well as collecting as much data as possible about the circumstances that led to the fault. A single-vehicle produces hundreds of gigabytes of data per month. The required data bandwidth cannot be fulfilled by current mobile network subscriptions as well as WIFI or cable-based infrastructure. This limits the amount of data that can be collected during field tests and hinders big data analysis like AI training or validation. Hence a software solution for data reduction is necessary. The authors present a method for data handling that drastically reduces the amount of data consumption and optimizes the transfer delay between a remote-diagnostic systems and the cloud. Using a pipeline of data preprocessing as well as an established compression algorithm, the amount of transmitted data is reduced by a factor of nearly ten. This method will allow to collect more data in field testing and improve the understanding of issues during vehicle development.</p></div>","PeriodicalId":100150,"journal":{"name":"Automotive and Engine Technology","volume":"7 3-4","pages":"307 - 316"},"PeriodicalIF":0.0,"publicationDate":"2022-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s41104-022-00113-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50489225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Encapsulated trajectory tracking control for autonomous vehicles","authors":"Tobias Homolla,&nbsp;Hermann Winner","doi":"10.1007/s41104-022-00114-8","DOIUrl":"10.1007/s41104-022-00114-8","url":null,"abstract":"<div><p>The motion control of autonomous vehicles with a modular, service-oriented system architecture poses new challenges, as trajectory-planning and -execution are independent software functions. In this paper, requirements for an encapsulated trajectory tracking control are derived and it’s shown that key differences to conventional vehicles with an integrated system architecture exist, requiring additional attention during controller design. A novel, encapsulated control architecture is presented that incorporates multiple extensions and support functions, fulfilling the derived requirements. It allows the application within the modular architecture without loss of functionality or performance. The controller considers vehicle stability and enables the yaw motion as an independent degree of freedom. The concept is applied and validated within the vehicles of the UNICAR<i>agil</i> research project, that feature the previously described system architecture to increase flexibility of application by dynamically interconnecting services based on the current use-case.</p></div>","PeriodicalId":100150,"journal":{"name":"Automotive and Engine Technology","volume":"7 3-4","pages":"295 - 306"},"PeriodicalIF":0.0,"publicationDate":"2022-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s41104-022-00114-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50513170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Combined experimental and simulative approach for friction loss optimization of DLC coated piston rings","authors":"Andreas Götze,&nbsp;Dirk Jaitner","doi":"10.1007/s41104-022-00115-7","DOIUrl":"10.1007/s41104-022-00115-7","url":null,"abstract":"<div><p>Piston rings cause significant friction losses within internal combustion engines. Especially the first compression ring, which is pressed onto the liner by high cylinder pressure, contributes significantly to the total friction loss of the piston assembly. The tribological behavior of the oil scraper ring is mainly related to the pretensioning force and can lead to high losses even at low and idle speed. Due to this, there is always a markable risk of wear for the contact surfaces of the piston rings and the cylinder. “Diamond-like carbon” coatings on the surface of the piston rings can prevent wear and are able to reduce friction in the ring-liner-contact. The purpose of this work was to investigate the tribological benefit of this coating-system on the compression and oil scraper ring. Experimental studies were carried out on a fired single-cylinder engine using the Indicated Instantaneous Mean Effective Pressure-method (IIMEP) for the crank angle-resolved detection of the piston assembly’s friction force. To be able to determine the component-related fractions of the friction loss and to quantify the hydrodynamic and asperity related parts locally and time dependent, an EHD/MBS model of the engine was created in AVL EXCITE and a simulative investigation was performed. This simulation was validated by the experimental work and provided detailed information about the individual contact conditions and gap height of each tribological contact of the piston group. The combined approach of measurement and simulation enabled the prediction of tribological aspects and performance in parameter studies on a virtual engine test bed.</p></div>","PeriodicalId":100150,"journal":{"name":"Automotive and Engine Technology","volume":"7 3-4","pages":"283 - 293"},"PeriodicalIF":0.0,"publicationDate":"2022-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s41104-022-00115-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50499216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Method for thermal evaluation of automotive gearbox packages taking into account load point-dependent oil distribution","authors":"Roland Uerlich,&nbsp;Theo Koch,&nbsp;Heiner Theising,&nbsp;Lutz Eckstein","doi":"10.1007/s41104-022-00109-5","DOIUrl":"10.1007/s41104-022-00109-5","url":null,"abstract":"<div><p>The spread of all-electric drives is steadily increasing in all sectors of road transport. Due to the constantly increasing demands on efficiency and performance by legislation and customers, it is necessary to continuously push the system limits of the powertrains. This paper presents an approach that performs an initial thermal system analysis based on a first gearbox configuration and efficiency calculation. Here, the componentwise loss calculation is used to identify thermal hotspots within the gearbox stage. The basis of this analysis is the thermal network method. For the approach, the gearbox elements gear, bearing, shaft, seal and housing are broken down into standard thermal elements to be created automatically for any subsequent gearbox configuration. The linking of these elements to each other is also standardised and automated comparably. An extensive simulation study is carried out using the smoothed particle hydrodynamics method to consider the load point-dependent oil distribution, which enables an initial estimate of the oil distribution. The thermal network filled in this way is then solved on a time-step basis, allowing dynamic load cases to be considered. The quality of the method is validated within the paper using the VW ID 3 gearbox as an example. Due to the use of a series gearbox, the validation was carried out on the basis of the accessible housing temperatures. These already show good convergence of the method compared to other existing approaches, which reinforces the necessity of conducting further experimental studies.</p></div>","PeriodicalId":100150,"journal":{"name":"Automotive and Engine Technology","volume":"7 3-4","pages":"245 - 264"},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s41104-022-00109-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50525905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lightweight, package and performance improvements of a shock tower by using steel–aluminium hybrid-casting technique","authors":"Lorenz Stolz,&nbsp;Hongli Xu,&nbsp;Xiangfan Fang","doi":"10.1007/s41104-022-00112-w","DOIUrl":"10.1007/s41104-022-00112-w","url":null,"abstract":"<div><p>In this work, a shock tower of a mid-size vehicle using steel (St)–aluminium (Al) hybrid-casting technology was developed with current shock towers as a benchmark. The use of this hybrid-casting technology, which features a ductile material connection between steel and cast aluminium, makes it possible to combine the design advantages of cast aluminium with the mechanical properties of high-strength steels. Based on this combination, a new shock tower concept was developed that offers advantages over the state of the art in terms of package, weight, stiffness and crash performance. To develop the new shock tower, connection points and package spaces in the periphery of the Honda Accord MY 2011 were analysed and defined. Based on quasi-static misuse load cases and topology optimization, it was possible to develop a load-compliant rib structure for the hybrid-cast shock tower reinforced by steel in the dome area. A so-called tension band for the IIHS small overlap crashworthiness evaluation test (SOL) was also integrated into the new shock tower to ensure homogeneous load distribution. The new shock tower was tested virtually in comparison with the reference steel shock tower and an Al-cast shock tower in quasi-static and dynamic crash load cases. In the quasi-static test, the hybrid-cast shock tower showed significantly increased stiffness. In the dynamic load cases, a significant overall homogenization of force distribution on the existing load paths in die front body structure was achieved. In addition, 5 mm package space for spring and damper could be gained for better driving behaviours of the car.\u0000</p></div>","PeriodicalId":100150,"journal":{"name":"Automotive and Engine Technology","volume":"7 3-4","pages":"265 - 281"},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s41104-022-00112-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50526405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}