Pub Date : 2020-11-13DOI: 10.1109/USEC50097.2020.9281246
K. Gulyamov, R. Yunusov, S. Dovudov, B. Sharifov, A. Ghulomzoda, M. Safaraliev
This paper provides the results of the study devoted to power increase for DC/DC converters with a larger number of channels. Possible options were demonstrated for bidirectional converters. Recommendations were given concerning using these types of converters in high-power electrical equipment, including electrical drives with their own power source. Battery electric cars are one of the ways to apply DC/DC converters. Battery cars wise, the aim is to increase voltage of a DC circuit and to reduce steady-state and transient current of a converter circuit. In addition, increasing voltage by means of using a DC/DC converter makes reducing of equipment weight and size of possible, since a battery of lower voltage and with a lower number of series elements can be used. Also by doing so battery control system can be simplified. Increased voltage of electric car circuits is required due to high standards in traction and speed performance. Consequently, power and torque should be high as well. The necessity for electric drives with higher voltage arises to meet the mentioned requirements. Hence, research of multi-channel bidirectional DC converters is relevant and urgent task.
{"title":"Increase in Power of DC/DC Converters with Increased Number of Conversion Channels","authors":"K. Gulyamov, R. Yunusov, S. Dovudov, B. Sharifov, A. Ghulomzoda, M. Safaraliev","doi":"10.1109/USEC50097.2020.9281246","DOIUrl":"https://doi.org/10.1109/USEC50097.2020.9281246","url":null,"abstract":"This paper provides the results of the study devoted to power increase for DC/DC converters with a larger number of channels. Possible options were demonstrated for bidirectional converters. Recommendations were given concerning using these types of converters in high-power electrical equipment, including electrical drives with their own power source. Battery electric cars are one of the ways to apply DC/DC converters. Battery cars wise, the aim is to increase voltage of a DC circuit and to reduce steady-state and transient current of a converter circuit. In addition, increasing voltage by means of using a DC/DC converter makes reducing of equipment weight and size of possible, since a battery of lower voltage and with a lower number of series elements can be used. Also by doing so battery control system can be simplified. Increased voltage of electric car circuits is required due to high standards in traction and speed performance. Consequently, power and torque should be high as well. The necessity for electric drives with higher voltage arises to meet the mentioned requirements. Hence, research of multi-channel bidirectional DC converters is relevant and urgent task.","PeriodicalId":236445,"journal":{"name":"2020 Ural Smart Energy Conference (USEC)","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129586820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-13DOI: 10.1109/USEC50097.2020.9281273
Y. Zatsarinnaya, A. Logacheva, K. Suslov, E. Stepanova
Today, any employer is interested in high-quality training of workers in the fuel and energy sector. For quality teaching, it is important not only to correctly plan and conduct training, but to monitor the quality of the educational process. Often, the assessment of the quality of training is limited to checking the employee’s knowledge immediately after the training. Monitoring changes in employee competence and behavior in the long term is not carried out due to the lack of ready-made tools. Thus, the long-term effect of training is not assessed, which can reduce its quality. The training process can turn into a formality that does not give qualitative changes in the competence of personnel. The authors of the article have developed a tool for assessing learning outcomes using the”360-degree assessment” method. The developed questionnaire may be used in the system for assessing the quality of educational by educational organization. This tool will be useful both for the educational organization and for the company that ordered the training. The results of the survey may be used by the educational organization to identify the need of corrective measures for the training course. The fuel and energy sector companies may use the results of the survey as a basis for choosing a contractor for the provision of educational services.
{"title":"360-Degree Assessment of Training Efficiency in Power Engineering Sector","authors":"Y. Zatsarinnaya, A. Logacheva, K. Suslov, E. Stepanova","doi":"10.1109/USEC50097.2020.9281273","DOIUrl":"https://doi.org/10.1109/USEC50097.2020.9281273","url":null,"abstract":"Today, any employer is interested in high-quality training of workers in the fuel and energy sector. For quality teaching, it is important not only to correctly plan and conduct training, but to monitor the quality of the educational process. Often, the assessment of the quality of training is limited to checking the employee’s knowledge immediately after the training. Monitoring changes in employee competence and behavior in the long term is not carried out due to the lack of ready-made tools. Thus, the long-term effect of training is not assessed, which can reduce its quality. The training process can turn into a formality that does not give qualitative changes in the competence of personnel. The authors of the article have developed a tool for assessing learning outcomes using the”360-degree assessment” method. The developed questionnaire may be used in the system for assessing the quality of educational by educational organization. This tool will be useful both for the educational organization and for the company that ordered the training. The results of the survey may be used by the educational organization to identify the need of corrective measures for the training course. The fuel and energy sector companies may use the results of the survey as a basis for choosing a contractor for the provision of educational services.","PeriodicalId":236445,"journal":{"name":"2020 Ural Smart Energy Conference (USEC)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131963089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-13DOI: 10.1109/USEC50097.2020.9281255
A. Arestova, I. Frolova, E. Sokol
The paper presents an algorithm for power distribution network structure optimization and software implementation of the approach. The software prototype includes life cycle cost objective function for oil and gas producing enterprise as an object of research. An ontological model has been developed to allow large amounts of complexly structured information to be shared it by experts and integrate software applications. The presented system solves the following tasks: optimal connection point to the existing power system, optimal topology of the power distribution network, equipment choosing, currents and voltages calculation, life cycle cost calculation. The optimization algorithm takes into account: the throughput capacity of the existing power system, the geography and soil types under the construction object, the cost of construction at different zones, the reliability of power supply and class of customers, the recommendations and requirements of the “Russian electrical Installations code”. Automated pre-design simulation of the power supply system allows you to: generate a fast model of the future construction object with minimal input information, quickly respond to changes in related areas of the project, introduce the customer’s personal preferences into the project design, assess the financial attractiveness of the project.
{"title":"Automated Power Distribution System Planning for Oil and Gas Industry","authors":"A. Arestova, I. Frolova, E. Sokol","doi":"10.1109/USEC50097.2020.9281255","DOIUrl":"https://doi.org/10.1109/USEC50097.2020.9281255","url":null,"abstract":"The paper presents an algorithm for power distribution network structure optimization and software implementation of the approach. The software prototype includes life cycle cost objective function for oil and gas producing enterprise as an object of research. An ontological model has been developed to allow large amounts of complexly structured information to be shared it by experts and integrate software applications. The presented system solves the following tasks: optimal connection point to the existing power system, optimal topology of the power distribution network, equipment choosing, currents and voltages calculation, life cycle cost calculation. The optimization algorithm takes into account: the throughput capacity of the existing power system, the geography and soil types under the construction object, the cost of construction at different zones, the reliability of power supply and class of customers, the recommendations and requirements of the “Russian electrical Installations code”. Automated pre-design simulation of the power supply system allows you to: generate a fast model of the future construction object with minimal input information, quickly respond to changes in related areas of the project, introduce the customer’s personal preferences into the project design, assess the financial attractiveness of the project.","PeriodicalId":236445,"journal":{"name":"2020 Ural Smart Energy Conference (USEC)","volume":"329 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133357563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-13DOI: 10.1109/USEC50097.2020.9281153
A. Fedorov, V. Petrov, O. Afanasieva, I. Zlobina
The estimation accuracy of traveling waves (TWs) arrival times, caused by a short circuit on the power line, to the installation location of the fault locator and, therefore, the ability to determine the fault location (FL), is largely determined by the level of the front of the TWs themselves: the lower TW level, the more difficult it is to recognize it. In this connection, it is obvious that it is necessary to calculate the power system regimes to determine the TW fronts values to estimate the TW fault location feasibility in a particular electrical network. When installing the TW fault locator, usually are compare the characteristic impedance beyond the bus with the characteristic impedance of the transmission line: if the first is less than the second preference is given to measuring current. Vice versa- preference is given to measuring the voltage. However, the existing methods do not take into account the influence on the TW value of the power system elements located between the short circuit and the locator and, like the characteristic impedance beyond the bus, which can significantly reduce the TW value. This approach can lead to the installation of the locator in the network, where it will be completely useless due to the insufficient for measurement TWs values. The purpose of this article is to determine the limitations of TWFL methods based on an analysis of TW front values for different network configuration and voltage classes.
{"title":"Limitations of Traveling Wave Fault Location","authors":"A. Fedorov, V. Petrov, O. Afanasieva, I. Zlobina","doi":"10.1109/USEC50097.2020.9281153","DOIUrl":"https://doi.org/10.1109/USEC50097.2020.9281153","url":null,"abstract":"The estimation accuracy of traveling waves (TWs) arrival times, caused by a short circuit on the power line, to the installation location of the fault locator and, therefore, the ability to determine the fault location (FL), is largely determined by the level of the front of the TWs themselves: the lower TW level, the more difficult it is to recognize it. In this connection, it is obvious that it is necessary to calculate the power system regimes to determine the TW fronts values to estimate the TW fault location feasibility in a particular electrical network. When installing the TW fault locator, usually are compare the characteristic impedance beyond the bus with the characteristic impedance of the transmission line: if the first is less than the second preference is given to measuring current. Vice versa- preference is given to measuring the voltage. However, the existing methods do not take into account the influence on the TW value of the power system elements located between the short circuit and the locator and, like the characteristic impedance beyond the bus, which can significantly reduce the TW value. This approach can lead to the installation of the locator in the network, where it will be completely useless due to the insufficient for measurement TWs values. The purpose of this article is to determine the limitations of TWFL methods based on an analysis of TW front values for different network configuration and voltage classes.","PeriodicalId":236445,"journal":{"name":"2020 Ural Smart Energy Conference (USEC)","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114546526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-13DOI: 10.1109/USEC50097.2020.9281179
Y. Soluyanov, A. Fedotov, A. Akhmetshin, V. Khalturin
To date, one of the most relevant tasks is a justified calculation of the electrical capacity of residential buildings and public facilities. Studies conducted by the “Roselectromontazh” Association have shown a significant difference between the actual and calculated electrical capacity, which is further confirmed by the reports of electric grid companies. In some cases, there is a 3-fold difference. This occurs due to the emergence of a sustainable culture of electricity consumption and the use of highly energy-efficient devices. In 2019, the results of the research work were taken into account in the regional urban planning standards of the Republic of Tatarstan. On average, the normative values have been reduced by 2 times. This enabled a significant reduction in the difference between the actual and calculated electrical capacity. From 2020 onwards, leading construction companies in the Republic of Tatarstan are applying up-to-date values to decrease utility services’ construction costs. For power grid companies the savings consist of reduction of electrical energy losses and “locked electrical capacity” and the elimination of inefficient investments. It is important to note that specific values of electrical load were calculated taking into account summer and winter peaks in order to exclude the emergencies. However, it was impossible to predict a time when people would need to stay self-isolated at home to prevent the spread of severe acute respiratory syndrome–related coronavirus SARS-CoV-2 (COVID-2019). Corresponding diagrams relative to 2019 were constructed to determine the impact of the electricity consumption of residential buildings during lockdown.
{"title":"Monitoring of Electrical Consumption, Including Self-Isolation During the COVID-19 Pandemic","authors":"Y. Soluyanov, A. Fedotov, A. Akhmetshin, V. Khalturin","doi":"10.1109/USEC50097.2020.9281179","DOIUrl":"https://doi.org/10.1109/USEC50097.2020.9281179","url":null,"abstract":"To date, one of the most relevant tasks is a justified calculation of the electrical capacity of residential buildings and public facilities. Studies conducted by the “Roselectromontazh” Association have shown a significant difference between the actual and calculated electrical capacity, which is further confirmed by the reports of electric grid companies. In some cases, there is a 3-fold difference. This occurs due to the emergence of a sustainable culture of electricity consumption and the use of highly energy-efficient devices. In 2019, the results of the research work were taken into account in the regional urban planning standards of the Republic of Tatarstan. On average, the normative values have been reduced by 2 times. This enabled a significant reduction in the difference between the actual and calculated electrical capacity. From 2020 onwards, leading construction companies in the Republic of Tatarstan are applying up-to-date values to decrease utility services’ construction costs. For power grid companies the savings consist of reduction of electrical energy losses and “locked electrical capacity” and the elimination of inefficient investments. It is important to note that specific values of electrical load were calculated taking into account summer and winter peaks in order to exclude the emergencies. However, it was impossible to predict a time when people would need to stay self-isolated at home to prevent the spread of severe acute respiratory syndrome–related coronavirus SARS-CoV-2 (COVID-2019). Corresponding diagrams relative to 2019 were constructed to determine the impact of the electricity consumption of residential buildings during lockdown.","PeriodicalId":236445,"journal":{"name":"2020 Ural Smart Energy Conference (USEC)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115438247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-13DOI: 10.1109/USEC50097.2020.9281269
N. Ivanov, V. Antonov, V. Naumov, A. Soldatov, M. Aleksandrova, E. Vorobyev
Energizing current of low-loaded highlycompensated power lines with shunt reactors mainly consists of an aperiodic component, and for a long time has not zerocrossing points. The modern SF6 circuit breaker fails to trip such power line immediately after energizing if unexpected fault or protection relay malfunction occurs because of commutation inability of aperiodic current. This leads to a long arc burning, and eventually to the breaker damage. The paper studies the transients during the commutation of the lowloaded power line and conditions when the amplitude of aperiodic component exceeds a safe level. The study shows that effective prevention of circuit breaker failure may be achieved using controlled switching technology assuming precision control a line energizing moment. The optimal reclosing moment is located near a beat minimum of the circuit breaker voltage and corresponds to the phase of supply voltage, at which the initial amplitude of the energizing current aperiodic component does not exceed the amplitude of the fundamental component. Reclosing of power line at the proposed optimal moment guarantees the safety of commutation for the circuit breaker and ensures mitigation of switching overvoltages.
{"title":"A Damage Prevention of Circuit Breaker During Energizing of Low-loaded Line with Shunt Reactors","authors":"N. Ivanov, V. Antonov, V. Naumov, A. Soldatov, M. Aleksandrova, E. Vorobyev","doi":"10.1109/USEC50097.2020.9281269","DOIUrl":"https://doi.org/10.1109/USEC50097.2020.9281269","url":null,"abstract":"Energizing current of low-loaded highlycompensated power lines with shunt reactors mainly consists of an aperiodic component, and for a long time has not zerocrossing points. The modern SF6 circuit breaker fails to trip such power line immediately after energizing if unexpected fault or protection relay malfunction occurs because of commutation inability of aperiodic current. This leads to a long arc burning, and eventually to the breaker damage. The paper studies the transients during the commutation of the lowloaded power line and conditions when the amplitude of aperiodic component exceeds a safe level. The study shows that effective prevention of circuit breaker failure may be achieved using controlled switching technology assuming precision control a line energizing moment. The optimal reclosing moment is located near a beat minimum of the circuit breaker voltage and corresponds to the phase of supply voltage, at which the initial amplitude of the energizing current aperiodic component does not exceed the amplitude of the fundamental component. Reclosing of power line at the proposed optimal moment guarantees the safety of commutation for the circuit breaker and ensures mitigation of switching overvoltages.","PeriodicalId":236445,"journal":{"name":"2020 Ural Smart Energy Conference (USEC)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121602999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-13DOI: 10.1109/USEC50097.2020.9281248
V. Samoylenko, P. Ilyushin, A. Pazderin
The paper presents a principle of a consequent hierarchical power and energy balancing in a power grid including a number of interconnected microgrids. Due to a load and intermittent energy sources output fluctuations, strong power and energy unbalances may arise in microgrids. These unbalances lead to inner and outer power and energy exchange that can be represented as the dispersion components of power and energy profiles. Compliance of the power balance is a part of microgrids’ secondary power regulation aimed at Area control error and power exchange keep given the limited interconnection capacity. Compliance of energy balance is a part of tertiary power regulation. It is of great importance for market settlements. An approach to semi-dispatchable distributed generation utilization for decreasing the power and energy dispersions taken by microgrids’ sources, and interconnecting microgrids power lines is considered. Different strategies of power and energy dispersions elimination applied to distinguishing load compositions are examined. An analysis show that generations’ typical power level and ramping settings corresponding to steady-state equipment operation enable to reduce the dispersion components in a great extent, although not to eliminate them at all. A mechanism of financial incentives for decreasing power flows dispersions is developed. It is based on a discount for technological interconnection due to maximum load decrease or discount for energy exchange price due to power and energy losses decrease.
{"title":"Balancing Unpredictable Load and Intermittent Renewables by Semi-Dispatchable Distributed Generation","authors":"V. Samoylenko, P. Ilyushin, A. Pazderin","doi":"10.1109/USEC50097.2020.9281248","DOIUrl":"https://doi.org/10.1109/USEC50097.2020.9281248","url":null,"abstract":"The paper presents a principle of a consequent hierarchical power and energy balancing in a power grid including a number of interconnected microgrids. Due to a load and intermittent energy sources output fluctuations, strong power and energy unbalances may arise in microgrids. These unbalances lead to inner and outer power and energy exchange that can be represented as the dispersion components of power and energy profiles. Compliance of the power balance is a part of microgrids’ secondary power regulation aimed at Area control error and power exchange keep given the limited interconnection capacity. Compliance of energy balance is a part of tertiary power regulation. It is of great importance for market settlements. An approach to semi-dispatchable distributed generation utilization for decreasing the power and energy dispersions taken by microgrids’ sources, and interconnecting microgrids power lines is considered. Different strategies of power and energy dispersions elimination applied to distinguishing load compositions are examined. An analysis show that generations’ typical power level and ramping settings corresponding to steady-state equipment operation enable to reduce the dispersion components in a great extent, although not to eliminate them at all. A mechanism of financial incentives for decreasing power flows dispersions is developed. It is based on a discount for technological interconnection due to maximum load decrease or discount for energy exchange price due to power and energy losses decrease.","PeriodicalId":236445,"journal":{"name":"2020 Ural Smart Energy Conference (USEC)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114977827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-13DOI: 10.1109/USEC50097.2020.9281245
P. Kovalenko, M. Senyuk, V. Mukhin, Diana D. Kornilova
The accelerated synchrophasor measurements algorithm is presented. The algorithm allows to evaluate synchrophasors with less than one basic frequency cycle time delay. The reference points method was suggested to determine the synchronous frequency, with magnitude and phase being calculated by means of extrema interpolation. Tests were carried out using the simulation data and the real data of the 110 kV, 220 kV, and 500 kV grids steady states and transients. Requirements for time delay of the suggested algorithm and sampling rate of the initial measurements data were formulated. The total vector error minimum was selected as the optimality criterion. Since the algorithm was tested on the real data without actual reference values, the alternative method of defining the total vector error was proposed. The suggested algorithm can be applied to protection & control systems based on the reactive action (the so-called “1-After” concept, when the set values of protection & control systems are calculated after a disturbance), development of dynamic power system models and generators technical state assessment.
{"title":"Synchrophasor Evaluation Based on Point-on-Wave Measurements","authors":"P. Kovalenko, M. Senyuk, V. Mukhin, Diana D. Kornilova","doi":"10.1109/USEC50097.2020.9281245","DOIUrl":"https://doi.org/10.1109/USEC50097.2020.9281245","url":null,"abstract":"The accelerated synchrophasor measurements algorithm is presented. The algorithm allows to evaluate synchrophasors with less than one basic frequency cycle time delay. The reference points method was suggested to determine the synchronous frequency, with magnitude and phase being calculated by means of extrema interpolation. Tests were carried out using the simulation data and the real data of the 110 kV, 220 kV, and 500 kV grids steady states and transients. Requirements for time delay of the suggested algorithm and sampling rate of the initial measurements data were formulated. The total vector error minimum was selected as the optimality criterion. Since the algorithm was tested on the real data without actual reference values, the alternative method of defining the total vector error was proposed. The suggested algorithm can be applied to protection & control systems based on the reactive action (the so-called “1-After” concept, when the set values of protection & control systems are calculated after a disturbance), development of dynamic power system models and generators technical state assessment.","PeriodicalId":236445,"journal":{"name":"2020 Ural Smart Energy Conference (USEC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116738164","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：