Xinyue Chen, Zhiwei Zhao, Mengru Zhu, Yong Fang, Z. Weng
As a wide bandgap semiconductor material, gallium oxide (Ga2O3) has a direct bandgap of 4.2-4.9 eV, which has excellent chemical and thermal properties. Thus it attracts great attention in solar-blind photodetection, transparent photonics, high-power appliances, etc. In this work, the chemical vapor deposition (CVD) is used for controllable growth of Ga2O3 by adjusting gas flow rate, the thickness of catalyst and distance from gallium (Ga) source, then the surface appearance and structure are analyzed. The results show that the optimized growth condition for Ga2O3 nanowires is at 950 ℃ heating for 3 h, gas flow rate of 68 sccm on the substrate with a catalyst thickness of 10 nm. EDS and XRD analysis confirme that the nanowires are β-Ga2O3, which is the most stable phases of Ga2O3. The detailed mechanism for the growth of Ga2O3 will be also presented in this article.
{"title":"Controllable Growth of Gallium Oxide Nanowires by Chemical Vapor Deposition","authors":"Xinyue Chen, Zhiwei Zhao, Mengru Zhu, Yong Fang, Z. Weng","doi":"10.1145/3508297.3508308","DOIUrl":"https://doi.org/10.1145/3508297.3508308","url":null,"abstract":"As a wide bandgap semiconductor material, gallium oxide (Ga2O3) has a direct bandgap of 4.2-4.9 eV, which has excellent chemical and thermal properties. Thus it attracts great attention in solar-blind photodetection, transparent photonics, high-power appliances, etc. In this work, the chemical vapor deposition (CVD) is used for controllable growth of Ga2O3 by adjusting gas flow rate, the thickness of catalyst and distance from gallium (Ga) source, then the surface appearance and structure are analyzed. The results show that the optimized growth condition for Ga2O3 nanowires is at 950 ℃ heating for 3 h, gas flow rate of 68 sccm on the substrate with a catalyst thickness of 10 nm. EDS and XRD analysis confirme that the nanowires are β-Ga2O3, which is the most stable phases of Ga2O3. The detailed mechanism for the growth of Ga2O3 will be also presented in this article.","PeriodicalId":285741,"journal":{"name":"2021 4th International Conference on Electronics and Electrical Engineering Technology","volume":"117 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126715758","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 article takes the large-scale doubly-fed wind farm into the power system as the background, considers the Crowbar circuit input and converter control strategy, and comprehensively considers the different voltage drop depths, slip rates, Crowbar resistance, and active power indicators of the doubly-fed wind turbine under grid fault. And reactive power indicators, theoretically calculate the positive and negative sequence impedance fluctuations on the wind turbine side when a fault occurs, combine the positive and negative sequence impedance fluctuations with the conventional sequence fault component directional element(FCDE) criterion, and analyze the sequence fault component directional element when the large-scale doubly-fed wind power is connected to power The adaptability of the system is finally verified by PSCAD/EMTDC simulation to verify the correctness of the theoretical analysis.
{"title":"Adaptability Analysis of Fault Component Directional Elements in the Transmission Line of Large-Scale Wind Farms","authors":"Ling Zhang, Qi Zhao, Dongliang Nan, Yanfang Fan, Yudun Li, Weimin Niu","doi":"10.1145/3508297.3508324","DOIUrl":"https://doi.org/10.1145/3508297.3508324","url":null,"abstract":"This article takes the large-scale doubly-fed wind farm into the power system as the background, considers the Crowbar circuit input and converter control strategy, and comprehensively considers the different voltage drop depths, slip rates, Crowbar resistance, and active power indicators of the doubly-fed wind turbine under grid fault. And reactive power indicators, theoretically calculate the positive and negative sequence impedance fluctuations on the wind turbine side when a fault occurs, combine the positive and negative sequence impedance fluctuations with the conventional sequence fault component directional element(FCDE) criterion, and analyze the sequence fault component directional element when the large-scale doubly-fed wind power is connected to power The adaptability of the system is finally verified by PSCAD/EMTDC simulation to verify the correctness of the theoretical analysis.","PeriodicalId":285741,"journal":{"name":"2021 4th International Conference on Electronics and Electrical Engineering Technology","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129910282","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 combination of spread-spectrum signal and correlation interferometer can achieve high precision, low interception and anti-interference direction finding, which is very important for autonomous cooperative positioning with aircraft formation.This paper presents a method to extract phase difference of direct sequence spread spectrum signal based on correlation peak position detection so as to realize spread spectrum signal correlation interferometer direction finding method, the simulation results show that the method has good performance, under the condition of low SNR of can obtain higher direction finding precision, greatly improving the concealment and anti-jamming in the system of direction finding.
{"title":"A Method of Direction-Finding based on Direct Sequence Spread Spectrum Signal Correlation Interferometer","authors":"Jiamiao Yao, Peng Yang, Linhua Zheng","doi":"10.1145/3508297.3508316","DOIUrl":"https://doi.org/10.1145/3508297.3508316","url":null,"abstract":"The combination of spread-spectrum signal and correlation interferometer can achieve high precision, low interception and anti-interference direction finding, which is very important for autonomous cooperative positioning with aircraft formation.This paper presents a method to extract phase difference of direct sequence spread spectrum signal based on correlation peak position detection so as to realize spread spectrum signal correlation interferometer direction finding method, the simulation results show that the method has good performance, under the condition of low SNR of can obtain higher direction finding precision, greatly improving the concealment and anti-jamming in the system of direction finding.","PeriodicalId":285741,"journal":{"name":"2021 4th International Conference on Electronics and Electrical Engineering Technology","volume":"616 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116272594","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 this paper, a developed system using an android-based mobile application to replace the conventional remote controllers of air conditioning units. This android mobile device will be used as a controller to switch the power of the air conditioning (AC) units and an accurate time power consumption monitoring for each AC unit. The study uses Android Studio for the android programming development and a NodeMCU ESP8266-12E microcontroller board to establish the network connectivity between the circuitry and the android mobile phone. The system used the Arduino Uno board to read the voltage sensor (ZMPT101B) shield and current sensor (SCT-013-030)'s data. After conducting the sensors' testing and calibrations, results showed significant accuracy of 96.95%. The power ON command for the AC units from the android mobile phone has an accuracy rate of 99.91% and 99.85% from that of the power OFF command. Power consumption calculation, on the other hand, has 91.09% accuracy.
{"title":"Android-Based Mobile Application for Managing the Laboratory Air Conditioning Units","authors":"Kimberly M. Nepa, Randy E. Angelia","doi":"10.1145/3508297.3508329","DOIUrl":"https://doi.org/10.1145/3508297.3508329","url":null,"abstract":"In this paper, a developed system using an android-based mobile application to replace the conventional remote controllers of air conditioning units. This android mobile device will be used as a controller to switch the power of the air conditioning (AC) units and an accurate time power consumption monitoring for each AC unit. The study uses Android Studio for the android programming development and a NodeMCU ESP8266-12E microcontroller board to establish the network connectivity between the circuitry and the android mobile phone. The system used the Arduino Uno board to read the voltage sensor (ZMPT101B) shield and current sensor (SCT-013-030)'s data. After conducting the sensors' testing and calibrations, results showed significant accuracy of 96.95%. The power ON command for the AC units from the android mobile phone has an accuracy rate of 99.91% and 99.85% from that of the power OFF command. Power consumption calculation, on the other hand, has 91.09% accuracy.","PeriodicalId":285741,"journal":{"name":"2021 4th International Conference on Electronics and Electrical Engineering Technology","volume":"15 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115813330","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 order to analyze the vibration characteristics of 220kV switch bay mobile load transfer equipment in complex road transportation environment, firstly, according to GJB150.16A-2009 "national military standard of the people's Republic of China - Environmental test methods for military equipment laboratory - vibration test", the power density spectrum of two wheeled trailer with relatively strong excitation in the standard is selected, which can reflect the more stringent environment, and then the vibration test is carried out The three-dimensional simulation model of the equipment is constructed, and the first ten natural frequencies of the equipment under fixed constraints are analyzed by the simulation software. Based on the natural frequency of the equipment and the selected power density spectrum, the random vibration simulation of the equipment is carried out, and the overall structure of the equipment is optimized and improved through the simulation results.
{"title":"Simulation Analysis on Seismic Capacity of 220kV GIS Switch Bay Mobile Load Transfer Equipment","authors":"Bo Liu, Wei Zhang, Zheng Wen, Zhen Wei, Zhuo Wang, Shujuan Li, Yuanyuan Hu, Wen-ling Li, Lisha Guo","doi":"10.1145/3508297.3508298","DOIUrl":"https://doi.org/10.1145/3508297.3508298","url":null,"abstract":"In order to analyze the vibration characteristics of 220kV switch bay mobile load transfer equipment in complex road transportation environment, firstly, according to GJB150.16A-2009 \"national military standard of the people's Republic of China - Environmental test methods for military equipment laboratory - vibration test\", the power density spectrum of two wheeled trailer with relatively strong excitation in the standard is selected, which can reflect the more stringent environment, and then the vibration test is carried out The three-dimensional simulation model of the equipment is constructed, and the first ten natural frequencies of the equipment under fixed constraints are analyzed by the simulation software. Based on the natural frequency of the equipment and the selected power density spectrum, the random vibration simulation of the equipment is carried out, and the overall structure of the equipment is optimized and improved through the simulation results.","PeriodicalId":285741,"journal":{"name":"2021 4th International Conference on Electronics and Electrical Engineering Technology","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130832947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
An experiment on vortex-induced vibration of the three-riser group in the 60°-staggered arrangement coupling interference effect is carried out to provide a theoretical reference and analysis basis for the design of riser groups. Based on the strains obtained by the fiber brag grating sensors and the modal decomposition theory, the concept of "interference efficiency" is introduced to analyze the dynamic characteristics and responses of the 60°-riser group. The riser model has an effective length of 2.0 m with an aspect ratio of 111.11. The adjacent risers are arranged at the spacing of 4 times the diameter. The results show that the 60°-riser group enters the "lock-in" region and the displacements reach "galloping" earlier than that of the isolated riser. High-order harmonic components appear in the in-line direction and the mode conversions are significant. Multi-frequency causes fatigue damage to be greatly aggravated. Therefore, the wake feedback effect and the interference of the gap flow can not be ignored.
{"title":"Investigation on Vortex-induced Vibration of the Staggered Riser Group Coupling Interference Effect","authors":"Yu Wang, Mingyang Lou, Pengfei Li","doi":"10.1145/3508297.3508337","DOIUrl":"https://doi.org/10.1145/3508297.3508337","url":null,"abstract":"An experiment on vortex-induced vibration of the three-riser group in the 60°-staggered arrangement coupling interference effect is carried out to provide a theoretical reference and analysis basis for the design of riser groups. Based on the strains obtained by the fiber brag grating sensors and the modal decomposition theory, the concept of \"interference efficiency\" is introduced to analyze the dynamic characteristics and responses of the 60°-riser group. The riser model has an effective length of 2.0 m with an aspect ratio of 111.11. The adjacent risers are arranged at the spacing of 4 times the diameter. The results show that the 60°-riser group enters the \"lock-in\" region and the displacements reach \"galloping\" earlier than that of the isolated riser. High-order harmonic components appear in the in-line direction and the mode conversions are significant. Multi-frequency causes fatigue damage to be greatly aggravated. Therefore, the wake feedback effect and the interference of the gap flow can not be ignored.","PeriodicalId":285741,"journal":{"name":"2021 4th International Conference on Electronics and Electrical Engineering Technology","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130838633","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}
Yuzheng Tang, Shuming Liu, Bo Zhang, Yi Wang, Chen Zheng
∗ The nonlinearity of phase-locked loops (PLLs) is a main reason whichcauses unstableoperationin grid-connectedconverters. How-ever, linearized methods or transient analysis cannot reveal the nonlinear characteristic of the PLL system. Furthermore, the stability criterion of the PLL is hard to be acquired under large-signal perturbations. In this paper, the LaSalle’s theory is employed to derive the stability boundaries of the PLLs. Once the grid parameters, the controller proportional-integral (PI) gains of the PLL, and the initial system states are given, the stability of the PLL system can be determined. The effectiveness of the proposed method is verified by detailed circuit simulations and experiments.
{"title":"Transient Stability Analysis of the Phase-Locked Loop in Grid-Connected Converters","authors":"Yuzheng Tang, Shuming Liu, Bo Zhang, Yi Wang, Chen Zheng","doi":"10.1145/3508297.3508311","DOIUrl":"https://doi.org/10.1145/3508297.3508311","url":null,"abstract":"∗ The nonlinearity of phase-locked loops (PLLs) is a main reason whichcauses unstableoperationin grid-connectedconverters. How-ever, linearized methods or transient analysis cannot reveal the nonlinear characteristic of the PLL system. Furthermore, the stability criterion of the PLL is hard to be acquired under large-signal perturbations. In this paper, the LaSalle’s theory is employed to derive the stability boundaries of the PLLs. Once the grid parameters, the controller proportional-integral (PI) gains of the PLL, and the initial system states are given, the stability of the PLL system can be determined. The effectiveness of the proposed method is verified by detailed circuit simulations and experiments.","PeriodicalId":285741,"journal":{"name":"2021 4th International Conference on Electronics and Electrical Engineering Technology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130942808","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 order to cope with the adverse effects of the disordered operation of hydropower units on the economic operation of Guangxi Power Grid, this paper proposes a virtual power plant based on improved economic model predictive control. The model consists of two parts: day-ahead rolling optimization and intra-day real-time feedback correction. The day-ahead rolling optimization aims to maximize the operating profit of the virtual power plant as the day-a-day scheduling goal. The day-ahead large-scale scheduling plan is formulated through multi-step rolling solution, in which the prediction domain length is adaptively selected according to the wind power output prediction domain error; the intra-day feedback correction takes into account the operating cost, Use the rolling optimization stage control plan as a benchmark to adjust the operating status of the equipment to deal with the uncertain changes in the small time scale of wind power. The analysis of multi-scenario calculation examples shows that the proposed scheduling model can realize the economic operation of virtual power plants, effectively cope with the uncertainty of wind power output, and realize the controllable adjustment of hydropower units, which verifies the feasibility and correctness of the model.
{"title":"Two-stage Optimal Control of Virtual Power Plant based on Improved Economic Model Predictive Control","authors":"Shuai Han, Leping Sun, Xiaoxuan Guo, Jianbin Lu","doi":"10.1145/3508297.3508300","DOIUrl":"https://doi.org/10.1145/3508297.3508300","url":null,"abstract":"In order to cope with the adverse effects of the disordered operation of hydropower units on the economic operation of Guangxi Power Grid, this paper proposes a virtual power plant based on improved economic model predictive control. The model consists of two parts: day-ahead rolling optimization and intra-day real-time feedback correction. The day-ahead rolling optimization aims to maximize the operating profit of the virtual power plant as the day-a-day scheduling goal. The day-ahead large-scale scheduling plan is formulated through multi-step rolling solution, in which the prediction domain length is adaptively selected according to the wind power output prediction domain error; the intra-day feedback correction takes into account the operating cost, Use the rolling optimization stage control plan as a benchmark to adjust the operating status of the equipment to deal with the uncertain changes in the small time scale of wind power. The analysis of multi-scenario calculation examples shows that the proposed scheduling model can realize the economic operation of virtual power plants, effectively cope with the uncertainty of wind power output, and realize the controllable adjustment of hydropower units, which verifies the feasibility and correctness of the model.","PeriodicalId":285741,"journal":{"name":"2021 4th International Conference on Electronics and Electrical Engineering Technology","volume":"289 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124159962","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 drafting or technical drawing of mechanical parts is a common activity during the phase of detailed design. Traditionally, engineering drawings are created manually by draftspersons with the support of CAD software, which is a time-consuming and error-prone task, requiring significant experience and a high level of technical expertise. To automate and accelerate this task, the present work introduces a new automatic drafting tool named iDrafter which enables the creation of 2D engineering drawings out of the 3D model's boundary representation (B-Rep). The iDrafter algorithm has been developed using a state-of-the-art CAD system Application Programming Interface (API) and incorporated into this system. The tool covers not only the dimensioning, but also other aspects of automatic drafting such as the creation of the drawing document, drawing sheet, and the corresponding views. To verify the algorithm, different CAD models have been subjected to testing.
{"title":"Towards Automated Drafting in CAD Systems","authors":"Mladen Buric, Mario Brčič, S. Škec","doi":"10.1145/3508297.3508335","DOIUrl":"https://doi.org/10.1145/3508297.3508335","url":null,"abstract":"The drafting or technical drawing of mechanical parts is a common activity during the phase of detailed design. Traditionally, engineering drawings are created manually by draftspersons with the support of CAD software, which is a time-consuming and error-prone task, requiring significant experience and a high level of technical expertise. To automate and accelerate this task, the present work introduces a new automatic drafting tool named iDrafter which enables the creation of 2D engineering drawings out of the 3D model's boundary representation (B-Rep). The iDrafter algorithm has been developed using a state-of-the-art CAD system Application Programming Interface (API) and incorporated into this system. The tool covers not only the dimensioning, but also other aspects of automatic drafting such as the creation of the drawing document, drawing sheet, and the corresponding views. To verify the algorithm, different CAD models have been subjected to testing.","PeriodicalId":285741,"journal":{"name":"2021 4th International Conference on Electronics and Electrical Engineering Technology","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124965139","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}
Distributed generation grid-connected inverter has similar software and hardware structures as active power filter(APF), static var compensator(STATCOM) and other active compensation equipment. In this paper, an improved conservative power theory (CPT) algorithm is proposed to extract harmonics, unbalance and reactive load current without introducing phase-locked loop (PLL), considering the influence of distorted voltage of PCC. On this basis, a power quality compensation scheme based on the proposed algorithm is designed and applied to build a multi-functional grid-connected inverter with power quality management function. The effectiveness and compensation performance of the proposed scheme is verified through simulation results.
{"title":"Research on Multi-functional Grid-connected Inverter based on Enhanced Conservative Power Theory","authors":"Wei Jin, Feng Gao, Lu Liu","doi":"10.1145/3508297.3508312","DOIUrl":"https://doi.org/10.1145/3508297.3508312","url":null,"abstract":"Distributed generation grid-connected inverter has similar software and hardware structures as active power filter(APF), static var compensator(STATCOM) and other active compensation equipment. In this paper, an improved conservative power theory (CPT) algorithm is proposed to extract harmonics, unbalance and reactive load current without introducing phase-locked loop (PLL), considering the influence of distorted voltage of PCC. On this basis, a power quality compensation scheme based on the proposed algorithm is designed and applied to build a multi-functional grid-connected inverter with power quality management function. The effectiveness and compensation performance of the proposed scheme is verified through simulation results.","PeriodicalId":285741,"journal":{"name":"2021 4th International Conference on Electronics and Electrical Engineering Technology","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130237731","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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