Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy最新文献_第5页

Waste heat utilization using organic rankine cycle from a pressurized pulverized combined cycle power plant 利用加压粉煤联合循环发电厂的有机秩循环利用余热

IF 1.7 4区工程技术

Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy Pub Date : 2024-03-19 DOI: 10.1177/09576509241240013

Nitesh Kumar Choudhary, Goutam Khankari, Sujit Karmakar

{"title":"Waste heat utilization using organic rankine cycle from a pressurized pulverized combined cycle power plant","authors":"Nitesh Kumar Choudhary, Goutam Khankari, Sujit Karmakar","doi":"10.1177/09576509241240013","DOIUrl":"https://doi.org/10.1177/09576509241240013","url":null,"abstract":"Power plants release a massive amount of waste heat at very low temperatures. Posing a challenge for efficient conversion into useful work through conventional methods. By selecting appropriate working fluids, low-grade power cycles can solve this problem by converting waste heat to electricity. The present work dealt with waste heat utilization using the Organic Rankine Cycle (ORC) from a 400 MWe coal based supercritical Pressurized Pulverized Combined Cycle (PPCC). The working fluid for the ORC is the refrigerant R245fa. High-ash (HA) Indian coal and low-ash (LA) South African coal are used as fuel to assess the plant’s ability to produce electricity under ambient conditions in India. The simulation flowsheet program “Cycle-Tempo” models and simulates different plant layouts. The thermodynamic assessment unveiled that the standalone plant has energy and exergy efficiencies of 43.46% and 39.87% for HA & 45.42% and 43.84% for LA, respectively. According to this study, the proposed plant has energy and exergy efficiencies of 44.63% and 40.94% for HA & 46.69% and 45.07% for LA, respectively. Moreover, using ORC, the waste heat generates additional electricity of 9.38 MWe, with an energy efficiency of 12.92% and exergy efficiency of 34.63%.","PeriodicalId":20705,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140171716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Application of a new DES model based on Wray-Agarwal turbulence model in flow simulation of a mixed-flow pump 基于 Wray-Agarwal 湍流模型的新型 DES 模型在混流泵流动模拟中的应用

IF 1.7 4区工程技术

Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy Pub Date : 2024-03-16 DOI: 10.1177/09576509241236533

Leilei Ji, Haoming Li, Wei Li, Weidong Shi, Shuo Li, Yang Yang, Chensong Zhao, Ramesh K Agarwal

{"title":"Application of a new DES model based on Wray-Agarwal turbulence model in flow simulation of a mixed-flow pump","authors":"Leilei Ji, Haoming Li, Wei Li, Weidong Shi, Shuo Li, Yang Yang, Chensong Zhao, Ramesh K Agarwal","doi":"10.1177/09576509241236533","DOIUrl":"https://doi.org/10.1177/09576509241236533","url":null,"abstract":"In recent years, it has been demonstrated for many two- and three-dimensional external and internal turbulent flows that the one-equation Wray-Agarwal turbulence model can compute the complex turbulent flow fields with high computational accuracy, excellent computational convergence and efficiency. In this paper, Wray-Agarwal (WA) turbulence model is employed as part of a detached eddy simulation (DES) method to predict the performance of a mixed-flow pump. By comparing the computations with the experimental results, the differences and similarities between the WA-DES model and the Shear Stress Transfer (SST) k-ω model in predicting the internal and external flow characteristics of the pump are analyzed. The results show that both the SST k-ω model and the WA-DES model can reasonably predict the performance of the pump between 0.6 Q and 1.2 Q, where Q is the design flow rate; however, they have their own merits and deficiencies in predicting head and efficiency of the pump at low and high flow rates. For the velocity field in the rotor-stator interaction region, the WA-DES model shows better prediction accuracy since it can accurately predict the large-scale recirculating vortex structure at the inlet of the guide vane. The SST k-ω model over-predicts the separated flow region, which leads to the emergence of a small vortex structure before the backflow region of the pump. Although the turbulent eddy viscosity predicted by the WA-DES model is higher than that of the SST k-ω model and there is small difference in the results for the scale of the tip leakage vortex (TLV) between the two models, the overall simulation results of the WA-DES model for the high turbulent viscosity region and the pressure increase in the impeller are consistent with the SST k-ω model results. The results of this paper demonstrate the potential of WA-DES model for prediction of flows in pumps.","PeriodicalId":20705,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140149497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Investigation into the predicted performance of a cooling fan for an sCO2 concentrated solar power plant 二氧化碳聚光太阳能发电厂冷却风机性能预测调查

IF 1.7 4区工程技术

Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy Pub Date : 2024-03-08 DOI: 10.1177/09576509241237840

Francois D Boshoff, Sybrand J van der Spuy, Johannes P Pretorius, Christiaan J Meyer

引用次数: 0

Energy loss mechanism of a full tubular pump under reverse power generation conditions using entropy production theory 利用熵产生理论研究反向发电条件下全管式泵的能量损失机理

IF 1.7 4区工程技术

Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy Pub Date : 2024-03-02 DOI: 10.1177/09576509241236825

Lijian Shi, Yiyu Chen, Xianlei Yu, Yi Han, Yao Chai, Muzi Xue

{"title":"Energy loss mechanism of a full tubular pump under reverse power generation conditions using entropy production theory","authors":"Lijian Shi, Yiyu Chen, Xianlei Yu, Yi Han, Yao Chai, Muzi Xue","doi":"10.1177/09576509241236825","DOIUrl":"https://doi.org/10.1177/09576509241236825","url":null,"abstract":"This paper investigates the energy dissipation mechanism of the internal flow field of the full tubular pump during reverse power generation and pump conditions, utilizing CFD and model test methods to research the device’s hydraulic characteristics, internal flow field and entropy production. The results indicate that the reverse power generation and pump conditions’ performance curves have opposite trends. Under PRPG conditions, the flow uniformity and weighted average angle of the impeller inlet flow field are smaller and the inlet flow field is poor. The stator-rotor gap flow under PRPG conditions increases with the increase in total flow, the gap flow under the design flow is 2.88 L/s, and the torque is 7.35 N·m. Under the PRPG condition, the turbulent and wall entropy production ratio increases gradually with the flow increase. Under the design flow rate, the entropy production rate of the impeller is 55.07%, and the entropy production rate of the impeller is the largest among the components under different flow rates. The entropy production of the outlet channel rises significantly with the flow rate. The research results of this paper provide a theoretical basis for the distribution of energy loss in reverse power generation of the full tubular pump.","PeriodicalId":20705,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140017036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Heat transfer characteristics of the air-oil heat exchanger with spiral tube 螺旋管空气-油热交换器的传热特性

IF 1.7 4区工程技术

Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy Pub Date : 2024-02-27 DOI: 10.1177/09576509241237006

Zhihai Kou, Baolin Cao, Qi Zhang, Binbin Li, Guangchao Li, Xunyan Yin

{"title":"Heat transfer characteristics of the air-oil heat exchanger with spiral tube","authors":"Zhihai Kou, Baolin Cao, Qi Zhang, Binbin Li, Guangchao Li, Xunyan Yin","doi":"10.1177/09576509241237006","DOIUrl":"https://doi.org/10.1177/09576509241237006","url":null,"abstract":"The cooling problem of hot-end components has become an important factor restricting the aero-engine performance, life and reliability. In order to improve the cooling quality of the cooling air, the supercritical aviation kerosene was used as a heat sink to cool the cooling air in a spiral heat exchanger. The flow and heat transfer process of the air-oil heat exchanger with spiral tube were numerically simulated using Fluent software. The flow and heat transfer situation of air and aviation kerosene were analyzed in detail. The optimized spiral heat exchanger with the diaphragm was presented to enhance the heat transfer capacity of the air side. It is found that the heat transfer performance of the air-oil heat exchanger is greatly enhanced by the spiral tube due to the secondary flow effect. With the increase in the turning angle of the spiral tube, the effect of the secondary flow for the heat transfer enhancement is strengthened. The PEC index of the spiral heat exchanger increases with the increase in the air flow rate. The spiral heat exchanger with the diaphragm can effectively improve the heat transfer performance of the heat exchanger, and increase the PEC index of the air side by more than 20%.","PeriodicalId":20705,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140009674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Investigation of non-axisymmetric endwall contouring in a high loaded turbine stator cascade 高负荷涡轮定子级联中的非轴对称端壁轮廓研究

IF 1.7 4区工程技术

Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy Pub Date : 2024-02-23 DOI: 10.1177/09576509241235977

Zhengshuai Du, Le Cai, Yingjie Chen, Songtao Wang, Hongfei Tang, Jun Zeng

{"title":"Investigation of non-axisymmetric endwall contouring in a high loaded turbine stator cascade","authors":"Zhengshuai Du, Le Cai, Yingjie Chen, Songtao Wang, Hongfei Tang, Jun Zeng","doi":"10.1177/09576509241235977","DOIUrl":"https://doi.org/10.1177/09576509241235977","url":null,"abstract":"The intensity and structure of the secondary flows have significant influences on the turbine cascade losses. Combining with the extension method of Non-linear Programming by Quadratic Lagrangian (NLPQLP), two endwall parametric methods respectively based on the B-spline surface and Fourier series are used to optimize the aerodynamic losses of a turbine cascade. The optimization processes are based on Computational Fluid Dynamics (CFD) analysis and two final designs are obtained by different methods. The endwall profile generated by the B-spline surface method (EW-B1) appears to relatively reduce the total pressure loss by 16.58% and the secondary kinetic energy coefficient ( C SKE) by 27.08%, while the endwall profile generated by the Fourier series method (EW-F1) relatively reduces the loss by 16.18% but increases C SKE by 8.99%. The radial movement of upper Passage Vortex (PV) and the weakening of the pressure branch of the Horseshoe Vortex (HVps) are confirmed to be the reasons of loss reduction in EW-B1, while the movement of PV is the main reason for EW-F1 to decrease the total pressure loss. In EW-B1, the weakening of HVps has a much more significant effect on the decrease in loss, which is affected by the non-axisymmetric shapes upstream of the vortex trajectory and the drop in C SKE generation near the throat.","PeriodicalId":20705,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139952525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Thermohydraulic performance parameter based experimental investigation of frustum shaped roughened solar air heater 基于热水力学性能参数的挫面粗化太阳能空气加热器实验研究

IF 1.7 4区工程技术

Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy Pub Date : 2024-01-29 DOI: 10.1177/09576509241227754

Dharam Singh, Vikash Kumar

{"title":"Thermohydraulic performance parameter based experimental investigation of frustum shaped roughened solar air heater","authors":"Dharam Singh, Vikash Kumar","doi":"10.1177/09576509241227754","DOIUrl":"https://doi.org/10.1177/09576509241227754","url":null,"abstract":"An outdoor experimental investigation was conducted to explore the thermohydraulic characteristic (Nusselt no. and friction factor) of artificial roughened solar air heater (ARSAH) having frustrum shaped roughened element on absorber plate. Data were recorded and further processed to generate Nusselt number and friction factor correlation to predict the effect of flow and roughness parameter on performance of ARSAH. The investigation was conducted by varying Reynolds number in range of 2500–12,500. Dimensionless parameter for Frustrum shaped roughness was relative frustum height (e/Dh) from 0.013 to 0.054, relative frustum pitch (p/e) from 8 to 14, Relative frustum height to base diameter (e/d1) from 0.37 to 0.75, relative frustum diametral ratio (d1/d2) from 1 to 3. Maximum performance for ARSAH was obtained corresponding to the optimum value of flow and geometric parameter. The geometric orientation of the proposed roughness geometry produced tremendous rise in Nu with an acceptable rise in friction (f). Maximum enhancement in Nu for varying p/e, e/Dh, e/d1, and d1/d2 was, 4.58, 5.21, 6.62 and 6.09 times and that of friction was 5.59, 4.69, 4.92 and 4.66 times respectively over conventional SAH. Maximum Thermohydraulic performance was 3.7, 3.6, 3.9 and 3.8 at p/e = 12, e/Dh = 0.054, e/d1 = 0.75 and d1/d2 = 3.","PeriodicalId":20705,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139952492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Investigating the onset and steady-state conditions of a diaphragm thermoacoustic stirling engine 研究隔膜式热声搅拌发动机的启动和稳态条件

IF 1.7 4区工程技术

Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy Pub Date : 2023-12-30 DOI: 10.1177/09576509231225277

S. Zare, A. Tavakolpour-Saleh, Amirhossein Hosseininia, M. H. Sangdani

{"title":"Investigating the onset and steady-state conditions of a diaphragm thermoacoustic stirling engine","authors":"S. Zare, A. Tavakolpour-Saleh, Amirhossein Hosseininia, M. H. Sangdani","doi":"10.1177/09576509231225277","DOIUrl":"https://doi.org/10.1177/09576509231225277","url":null,"abstract":"This work investigates the onset and steady-state conditions of diaphragm thermoacoustic Stirling engines using the averaging-based Lyapunov technique for the first time. First, the diaphragm thermoacoustic Stirling engine is introduced. Next, the startup conditions, including the onset condition and existence of a stable limit cycle (steady-state) of the engine are studied based on the alteration of the mass connected to the diaphragm of SUTech-SR-3 in the range of 88.2 g to 121.2 g. The simulation results obtained from the averaging-based Lyapunov technique show the engine can run only in the mass range of 90.4 g to 119 g. On the other hand, to validate the simulation outcomes, this assessment is carried out experimentally. The practical results confirm the extracted outcomes from this method. Based on the allowable range acquired from this technique, the effect of the change in the value of the mass connected to the engine diaphragm on the operating frequency is investigated experimentally. This work shows that the employed method can be a helpful means to investigate the startup conditions of the diaphragm thermoacoustic Stirling engines.","PeriodicalId":20705,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2023-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139139455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Optimization of low-head shaft tubular pumping systems based on entropy production theory 基于熵产生理论的低扬程轴管式泵送系统优化

IF 1.7 4区工程技术

Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy Pub Date : 2023-12-18 DOI: 10.1177/09576509231222670

Yuqi Wang, Weixuan Jiao, Li Cheng, Heng Zhao, Yulan Zhu, C. Luo, Libo Dou

{"title":"Optimization of low-head shaft tubular pumping systems based on entropy production theory","authors":"Yuqi Wang, Weixuan Jiao, Li Cheng, Heng Zhao, Yulan Zhu, C. Luo, Libo Dou","doi":"10.1177/09576509231222670","DOIUrl":"https://doi.org/10.1177/09576509231222670","url":null,"abstract":"In order to improve the operation efficiency of low-head tubular pump, this paper studies the influence of shaft type in the shaft tubular pump on the flow characteristics and energy characteristics of the pump. To optimize the shaft structure of shaft tubular pumping systems and realize the efficient use of energy, numerical simulation and model test was employed to study the optimization of the entire pumping system. In this paper, the CFD method was used to numerically simulate the whole pumping system, and the effect of changing the shaft length, shaft head profile, and shaft tail profile on the internal flow and entropy production characteristics of the inlet passage and impeller position were analyzed. It is found that the tapered tail profile can make the inlet passage overflow area change more smoothly and thus make the flow pattern more favorable. The wall entropy production dissipation at the inlet passage position dominates the total entropy production, and the high-value area of mainstream entropy production at this position is distributed periodically. The mainstream entropy production dissipation at the impeller section accounts for a relatively large proportion. After the entropy production dissipation analysis, it is believed that the tapered can reduce the entropy production dissipation of the pumping systems. The change of the shaft tail profile will make the entropy production dissipation change more noticeable compared with other optimization factors. Therefore, the tapered tail profile with better transition in the actual project is recommended.","PeriodicalId":20705,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138994699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of parasitic losses on the design optimization of inward flow radial supercritical CO2 turbines 寄生损耗对内流径向超临界二氧化碳涡轮机设计优化的影响

IF 1.7 4区工程技术

Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy Pub Date : 2023-12-13 DOI: 10.1177/09576509231221007

Syed J Hoque, S. Lanjewar, Pramod Kumar

{"title":"Effect of parasitic losses on the design optimization of inward flow radial supercritical CO2 turbines","authors":"Syed J Hoque, S. Lanjewar, Pramod Kumar","doi":"10.1177/09576509231221007","DOIUrl":"https://doi.org/10.1177/09576509231221007","url":null,"abstract":"Inward flow radial (IFR) supercritical CO2 (sCO2) turbines are smaller in size and operate at considerably higher speeds in comparison to similar capacity conventional gas or steam turbines. The compact size and high speed of IFR turbines result in significant parasitic (leakage and disk friction) losses at the rotor backface. This paper presents CFD investigations to understand the mechanism of parasitic losses of IFR turbines in the kW to MW power scales. The first part of the paper presents a parametric study to quantify the effect of backface flowpath dimensions, rotor inlet radius, and rotational speed on the magnitude of parasitic losses. Subsequently, the paper proposes the implementation of a radial labyrinth seal on the rotor backface to curtail the parasitic losses. The second part of the paper examines how the power scale of the turbine and its design parameters, specific speed and velocity ratio, influence the magnitude of parasitic losses. The investigation reveals that parasitic losses cause an efficiency drop of 8%–15% for 100 kW and 4%–9% for 1 MW IFR sCO2 turbines. In addition, IFR turbines designed for low specific speeds and high velocity ratios result in notably higher parasitic losses, leading to a decline in turbine efficiency. Finally, the paper presents optimal turbine design parameters accounting for the parasitic losses to maximize turbine efficiency.","PeriodicalId":20705,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139006794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0