The cryostat is a vacuum tight container enveloping the entire basic systems of the ITER tokamak machine,including a vacuum vessel,a superconducting magnet and thermal shield etc.It is evacuated to a pressure of 10^-4...The cryostat is a vacuum tight container enveloping the entire basic systems of the ITER tokamak machine,including a vacuum vessel,a superconducting magnet and thermal shield etc.It is evacuated to a pressure of 10^-4Pa to limit the heat transfer via gas conduction and convection to the cryogenically cooled components.Another important function of cryostat is to support all the loads from the tokamak to the concrete floor of the pit by its support system during different operational regimes and accident scenarios.This paper briefly presents the design evolution and associated analysis of the cryostat support system and the structural interface with the building.展开更多
Water-spraying is regarded as an effective method to reduce the weight loss of product during vacuum cooling process.This study aimed to investigate the effect of vacuum cooling factors on the weight loss of postharve...Water-spraying is regarded as an effective method to reduce the weight loss of product during vacuum cooling process.This study aimed to investigate the effect of vacuum cooling factors on the weight loss of postharvest broccoli,and attempted to optimize the treatment conditions by simulated annealing(SA)technique.An algorithm based on simulated annealing meta-heuristic technique was developed to identify the optimum condition for vacuum cooling treatment of broccoli.Results demonstrated that the SA algorithm could adjust well with the simulation of the broccoli cooling process.The best condition was at 200 Pa of pressure,274 g broccoli,6% of water volume and 40 min processing time.Under this condition,a product with only 0.35% of weight loss and 1.48℃ final temperature was obtained.The developed method may help to effectively control the weight loss during vacuum cooling process and reducing the economic loss.展开更多
This study aimed to investigate and compare the effects of vacuum cooling,cooling water and cold room methods on the shelf life of broccoli.The experiments were divided into four groups:vacuum cooling(A),ice-water coo...This study aimed to investigate and compare the effects of vacuum cooling,cooling water and cold room methods on the shelf life of broccoli.The experiments were divided into four groups:vacuum cooling(A),ice-water cooling(B),cold room cooling(C)and control.The cooling rate and changes of weight loss,respiratory rate,chlorophyll,vitamin C,reducing sugar content and sensory properties were measured at intervals of five days.The results indicated that vacuum cooling was the most effective method for extending the shelf life of postharvest broccoli in terms of cooling rate,respiration rate,chlorophyll,vitamin C,reducing sugar and sensory properties.Moreover,spraying the broccoli with water during the vacuum cooling process resulted in a significant reduction in weight compared with the other two cooling methods and did not reduce the quality of the broccoli.Consequently,vacuum cooling treatment can be applied to broccoli after harvest in the field to maintain quality during transportation and storage.Additionally,the application of water spraying during vacuum cooling can considerably reduce the negative influence caused by vacuum cooling.展开更多
文摘The cryostat is a vacuum tight container enveloping the entire basic systems of the ITER tokamak machine,including a vacuum vessel,a superconducting magnet and thermal shield etc.It is evacuated to a pressure of 10^-4Pa to limit the heat transfer via gas conduction and convection to the cryogenically cooled components.Another important function of cryostat is to support all the loads from the tokamak to the concrete floor of the pit by its support system during different operational regimes and accident scenarios.This paper briefly presents the design evolution and associated analysis of the cryostat support system and the structural interface with the building.
基金the financial support by Chinese National Key Technology R&D Program(Grant No.2012BAD31B06)Key Technology R&D Program of Ningbo(Grant No.2013C11007)the Fundamental Research Funds fo r the Central Universities.
文摘Water-spraying is regarded as an effective method to reduce the weight loss of product during vacuum cooling process.This study aimed to investigate the effect of vacuum cooling factors on the weight loss of postharvest broccoli,and attempted to optimize the treatment conditions by simulated annealing(SA)technique.An algorithm based on simulated annealing meta-heuristic technique was developed to identify the optimum condition for vacuum cooling treatment of broccoli.Results demonstrated that the SA algorithm could adjust well with the simulation of the broccoli cooling process.The best condition was at 200 Pa of pressure,274 g broccoli,6% of water volume and 40 min processing time.Under this condition,a product with only 0.35% of weight loss and 1.48℃ final temperature was obtained.The developed method may help to effectively control the weight loss during vacuum cooling process and reducing the economic loss.
基金financial support by Key Technology R&D Program of Ningbo(Grant No.2013C11007)Zhejiang Provincial Public Technology Research Plan(Grant No.2014C32033).
文摘This study aimed to investigate and compare the effects of vacuum cooling,cooling water and cold room methods on the shelf life of broccoli.The experiments were divided into four groups:vacuum cooling(A),ice-water cooling(B),cold room cooling(C)and control.The cooling rate and changes of weight loss,respiratory rate,chlorophyll,vitamin C,reducing sugar content and sensory properties were measured at intervals of five days.The results indicated that vacuum cooling was the most effective method for extending the shelf life of postharvest broccoli in terms of cooling rate,respiration rate,chlorophyll,vitamin C,reducing sugar and sensory properties.Moreover,spraying the broccoli with water during the vacuum cooling process resulted in a significant reduction in weight compared with the other two cooling methods and did not reduce the quality of the broccoli.Consequently,vacuum cooling treatment can be applied to broccoli after harvest in the field to maintain quality during transportation and storage.Additionally,the application of water spraying during vacuum cooling can considerably reduce the negative influence caused by vacuum cooling.
