Ulsan port is the hugest industry-oriented port in South Korea. It has the third highest traffic volume of cargo, and also it has the most liquid bulk in Korea. However, on account of thoughtless development, there ar...Ulsan port is the hugest industry-oriented port in South Korea. It has the third highest traffic volume of cargo, and also it has the most liquid bulk in Korea. However, on account of thoughtless development, there are other cases like Ulsan port that liquid cargo and general cargo are simultaneously handled. The demurrage ratio takes up to 12.5% of probability on average. In 2010, it has less room at berths for liquid bulk than general cargo and it totally has 107% of processing ratio （throughput）. This indicates that Ulsan port concentrates on liquid cargo more than general cargo depending on the characteristics of the port. This research suggests the effects as alternatives for efficiency and effectivity at both ports, Ulsan port and Pohang port in the case that the general cargo handled in Ulsan port is relocated to Pohang port in terms of the characteristics of products which Pohang port and its hinterland the most focused on. Namely, we estimate volume of relocated volume suitable for relocation in assumption that volume handled in Ulsan port is relocated to Pohang port scenario by scenario, analyze the effects of relocated volume, and suggest alternatives for vitalizing Ulsan port.展开更多
The reversible solid oxide cell(RSOC)is an attractive technology to mutually convert power and chemicals at elevated temperatures.However,its development has been hindered mainly due to the absence of a highly active ...The reversible solid oxide cell(RSOC)is an attractive technology to mutually convert power and chemicals at elevated temperatures.However,its development has been hindered mainly due to the absence of a highly active and durable fuel electrode.Here,we report a phase-transformed CoFe-Sr_(3)Fe_(1.25)Mo_(0.75)O_(7)-δ(CoFe-SFM)fuel electrode consisting of CoFe nanoparticles and Ruddlesden-Popper-layered Sr_(3)Fe_(1.25)Mo_(0.75)O_(7)-δ(SFM)from a Sr_(2)Fe_(7/6)Mo_(0.5)Co_(1/3)O_(6)-δ(SFMCo)perovskite oxide after annealing in hydrogen and apply it to reversible CO/CO_(2)conversion in RSOC.The CoFeSFM fuel electrode shows improved catalytic activity by accelerating oxygen diffusion and surface kinetics towards the CO/CO_(2)conversion as demonstrated by the distribution of relaxation time(DRT)study and equivalent circuit model fitting analysis.Furthermore,an electrolyte-supported single cell is evaluated in the 2:1 CO-CO_(2)atmosphere at 800℃,which shows a peak power density of 259 mW cm^(-2)for CO oxidation and a current density of-0.453 A cm^(-2)at 1.3 V for CO_(2)reduction,which correspond to 3.079 and3.155 m L min-1cm^(-2)for the CO and CO_(2)conversion rates,respectively.More importantly,the reversible conversion is successfully demonstrated over 20 cyclic electrolysis and fuel cell switching test modes at 1.3 and 0.6 V.This work provides a useful guideline for designing a fuel electrode through a surface/interface exsolution process for RSOC towards efficient CO-CO_(2)reversible conversion.展开更多
In this paper, a system of fractional differential equations that model the synchronized bioluminescence behavior of a set of fireflies put on two spatial arrangements is presented; the alternative representation of t...In this paper, a system of fractional differential equations that model the synchronized bioluminescence behavior of a set of fireflies put on two spatial arrangements is presented; the alternative representation of these equations contains fractional operators of IAouvillc-Caputo type. The objective of the model is to qualitatively recover synchronization and show that it is persistent. It is shown that the effort made by each firefly glow changes with respect to the number of male competitors and the distance between them. The conditions on biological parameters are interpreted.展开更多
文摘Ulsan port is the hugest industry-oriented port in South Korea. It has the third highest traffic volume of cargo, and also it has the most liquid bulk in Korea. However, on account of thoughtless development, there are other cases like Ulsan port that liquid cargo and general cargo are simultaneously handled. The demurrage ratio takes up to 12.5% of probability on average. In 2010, it has less room at berths for liquid bulk than general cargo and it totally has 107% of processing ratio （throughput）. This indicates that Ulsan port concentrates on liquid cargo more than general cargo depending on the characteristics of the port. This research suggests the effects as alternatives for efficiency and effectivity at both ports, Ulsan port and Pohang port in the case that the general cargo handled in Ulsan port is relocated to Pohang port in terms of the characteristics of products which Pohang port and its hinterland the most focused on. Namely, we estimate volume of relocated volume suitable for relocation in assumption that volume handled in Ulsan port is relocated to Pohang port scenario by scenario, analyze the effects of relocated volume, and suggest alternatives for vitalizing Ulsan port.
基金financially supported by the National Natural Science Foundation (52002249,51402093 and 21706162)Guangdong Basic and Applied Basic Research Foundation (2019A1515110025 and 2017A 030313289)+3 种基金the Research Grant for Scientific Platform and Project of Guangdong Provincial Education Office (2019KTSCX151)China Postdoctoral Science Foundation (2020M682872)Shenzhen Government’s Plan of Science and Technology (JCYJ201803005125247308)Technical support from the Instrumental Analysis Center of Shenzhen University (Xili Campus) is also appreciated。
文摘The reversible solid oxide cell(RSOC)is an attractive technology to mutually convert power and chemicals at elevated temperatures.However,its development has been hindered mainly due to the absence of a highly active and durable fuel electrode.Here,we report a phase-transformed CoFe-Sr_(3)Fe_(1.25)Mo_(0.75)O_(7)-δ(CoFe-SFM)fuel electrode consisting of CoFe nanoparticles and Ruddlesden-Popper-layered Sr_(3)Fe_(1.25)Mo_(0.75)O_(7)-δ(SFM)from a Sr_(2)Fe_(7/6)Mo_(0.5)Co_(1/3)O_(6)-δ(SFMCo)perovskite oxide after annealing in hydrogen and apply it to reversible CO/CO_(2)conversion in RSOC.The CoFeSFM fuel electrode shows improved catalytic activity by accelerating oxygen diffusion and surface kinetics towards the CO/CO_(2)conversion as demonstrated by the distribution of relaxation time(DRT)study and equivalent circuit model fitting analysis.Furthermore,an electrolyte-supported single cell is evaluated in the 2:1 CO-CO_(2)atmosphere at 800℃,which shows a peak power density of 259 mW cm^(-2)for CO oxidation and a current density of-0.453 A cm^(-2)at 1.3 V for CO_(2)reduction,which correspond to 3.079 and3.155 m L min-1cm^(-2)for the CO and CO_(2)conversion rates,respectively.More importantly,the reversible conversion is successfully demonstrated over 20 cyclic electrolysis and fuel cell switching test modes at 1.3 and 0.6 V.This work provides a useful guideline for designing a fuel electrode through a surface/interface exsolution process for RSOC towards efficient CO-CO_(2)reversible conversion.
文摘In this paper, a system of fractional differential equations that model the synchronized bioluminescence behavior of a set of fireflies put on two spatial arrangements is presented; the alternative representation of these equations contains fractional operators of IAouvillc-Caputo type. The objective of the model is to qualitatively recover synchronization and show that it is persistent. It is shown that the effort made by each firefly glow changes with respect to the number of male competitors and the distance between them. The conditions on biological parameters are interpreted.
