In order to produce low-cost titanium(Ti)with high productivity,fundamental studies on producing metallic Ti from titanium dioxide(TiO2)in the cold pressed pellets were conducted by metallothermic reduction with an in...In order to produce low-cost titanium(Ti)with high productivity,fundamental studies on producing metallic Ti from titanium dioxide(TiO2)in the cold pressed pellets were conducted by metallothermic reduction with an indirect contact method.This paper focuses on discussing the mechanism of the reduction process and the relationships of RM(a revised reduction index)with reduction temperature,reduction time,and mole ratio of TiO2 to CaCl2(nTiO2/nCaCl2)in the pellets.The results show that metallic Ti was obtained from the reduction of TiO2 in the pellets by calcium(Ca)vapor;pellets were reduced homogenously and Ca vapor diffused into the porous pellets by Knudsen diffusion or the mixing diffusion of molecular diffusion and Knudsen diffusion at 1273 K;RM increased with the increases of temperature and reduction time and was 96.34%when TRedu=1273 K,tRedu=6 h,and nTiO2/nCaCl2=4;the reasonable nTiO2/nCaCl2 value is 3−5 for the pellets with enough strength and high RM.展开更多
The Cold Eddy in the East China Sea(CEECS) is located about 150 km southwest of Cheju Island.This region experiences a complex current system under the influences of the Yellow Sea Warm Current(YSWC),the Yellow Sea Co...The Cold Eddy in the East China Sea(CEECS) is located about 150 km southwest of Cheju Island.This region experiences a complex current system under the influences of the Yellow Sea Warm Current(YSWC),the Yellow Sea Coastal Current(YSCC),and the northward Kuroshio residual.To identify the strength of the CEECS,a simple subsurface intensity index is developed.Because the CEECS can be traced by temperature minimum,the intensity index is determined by the difference in sea temperature averaged across cores within and surrounding the region.Based on SODA,the CEECS subsurface intensity index time series can be calculated,with which the inter-annual variation of the CEECS is analyzed.展开更多
This study was designed to evaluate the sensory quality indices, freshness assessment and safety of eating Nile tilapia fed recycled food waste materials [food industry waste （FIW） and soy sauce waste （SSW）] for 3...This study was designed to evaluate the sensory quality indices, freshness assessment and safety of eating Nile tilapia fed recycled food waste materials [food industry waste （FIW） and soy sauce waste （SSW）] for 32 weeks using K values, IMP content and microbial viable cell count. Five experimental diets were formulated at 0% and 20%-22% inclusion level of recycled food wastes. The diets were designated as D 1： 0% of recycled food waste, D2： 20% inclusion of FIW, D3： 20% inclusion of FIW and SSW, D4： 20% inclusion of FIW and tryptophan, and D5： 22% inclusion of SSW. The result from the body composition shows that D I had higher carcass protein, while D3 had the highest lipid content and there was no significant difference in the carcass moisture and ash contents among all treatments. The results of microbial viable cell counts showed that no significant differences were observed among the dietary treatments and all the fish fed experimental diets still remained fresh four days after refrigerated storage at 5 ~C. In addition, no significant differences were noted among the K value concentrations of all the fish fed the experimental diets. From the result of this study, we concluded that using 20% inclusion of recycled food waste materials （FIW and SSW） in the diet of tilapia had no negative effect on the flesh of the fish; hence, recycled food waste could be a good alternative ingredient to aquaculture.展开更多
In this paper we present a stochastic model for daily average temperature to calculate the temperature indices upon which temperature-based derivatives are written. We propose a seasonal mean and volatility model that...In this paper we present a stochastic model for daily average temperature to calculate the temperature indices upon which temperature-based derivatives are written. We propose a seasonal mean and volatility model that describes the daily average temperature behavior using the mean-reverting Ornstein-Uhlenbeck process. We also use higher order continuous-time autoregressive process with lag 3 for modeling the time evolution of the temperatures after removing trend and seasonality. Our model is fitted to 11 years of data recorded, in the period 1 January 2005 to 31 December 2015, Bahir Dar, Ethiopia, obtained from Ethiopia National Meteorological Services Agency. The analytical approximation formulas are used to price heating degree days(HDD) and cooling degree days(CDD) futures. The suggested model is analytically tractable for derivation of explicit prices for CDD and HDD futures and option. The price of the CDD future is calculated, using analytical approximation formulas. Numerical examples are presented to indicate the accuracy of the method. The results show that our model performs better to predict CDD indices.展开更多
基金Projects(51774071,50804007,51974073)supported by the National Natural Science Foundation of China。
文摘In order to produce low-cost titanium(Ti)with high productivity,fundamental studies on producing metallic Ti from titanium dioxide(TiO2)in the cold pressed pellets were conducted by metallothermic reduction with an indirect contact method.This paper focuses on discussing the mechanism of the reduction process and the relationships of RM(a revised reduction index)with reduction temperature,reduction time,and mole ratio of TiO2 to CaCl2(nTiO2/nCaCl2)in the pellets.The results show that metallic Ti was obtained from the reduction of TiO2 in the pellets by calcium(Ca)vapor;pellets were reduced homogenously and Ca vapor diffused into the porous pellets by Knudsen diffusion or the mixing diffusion of molecular diffusion and Knudsen diffusion at 1273 K;RM increased with the increases of temperature and reduction time and was 96.34%when TRedu=1273 K,tRedu=6 h,and nTiO2/nCaCl2=4;the reasonable nTiO2/nCaCl2 value is 3−5 for the pellets with enough strength and high RM.
基金Supported by National Basic Research Program of China (Nos. 2005CB422307, 2007CB411803)Program for New Century Excellent Talents in University (NCET-08-0510)National 908 Program of China (No. 908-02-02-02)
文摘The Cold Eddy in the East China Sea(CEECS) is located about 150 km southwest of Cheju Island.This region experiences a complex current system under the influences of the Yellow Sea Warm Current(YSWC),the Yellow Sea Coastal Current(YSCC),and the northward Kuroshio residual.To identify the strength of the CEECS,a simple subsurface intensity index is developed.Because the CEECS can be traced by temperature minimum,the intensity index is determined by the difference in sea temperature averaged across cores within and surrounding the region.Based on SODA,the CEECS subsurface intensity index time series can be calculated,with which the inter-annual variation of the CEECS is analyzed.
文摘This study was designed to evaluate the sensory quality indices, freshness assessment and safety of eating Nile tilapia fed recycled food waste materials [food industry waste （FIW） and soy sauce waste （SSW）] for 32 weeks using K values, IMP content and microbial viable cell count. Five experimental diets were formulated at 0% and 20%-22% inclusion level of recycled food wastes. The diets were designated as D 1： 0% of recycled food waste, D2： 20% inclusion of FIW, D3： 20% inclusion of FIW and SSW, D4： 20% inclusion of FIW and tryptophan, and D5： 22% inclusion of SSW. The result from the body composition shows that D I had higher carcass protein, while D3 had the highest lipid content and there was no significant difference in the carcass moisture and ash contents among all treatments. The results of microbial viable cell counts showed that no significant differences were observed among the dietary treatments and all the fish fed experimental diets still remained fresh four days after refrigerated storage at 5 ~C. In addition, no significant differences were noted among the K value concentrations of all the fish fed the experimental diets. From the result of this study, we concluded that using 20% inclusion of recycled food waste materials （FIW and SSW） in the diet of tilapia had no negative effect on the flesh of the fish; hence, recycled food waste could be a good alternative ingredient to aquaculture.
文摘In this paper we present a stochastic model for daily average temperature to calculate the temperature indices upon which temperature-based derivatives are written. We propose a seasonal mean and volatility model that describes the daily average temperature behavior using the mean-reverting Ornstein-Uhlenbeck process. We also use higher order continuous-time autoregressive process with lag 3 for modeling the time evolution of the temperatures after removing trend and seasonality. Our model is fitted to 11 years of data recorded, in the period 1 January 2005 to 31 December 2015, Bahir Dar, Ethiopia, obtained from Ethiopia National Meteorological Services Agency. The analytical approximation formulas are used to price heating degree days(HDD) and cooling degree days(CDD) futures. The suggested model is analytically tractable for derivation of explicit prices for CDD and HDD futures and option. The price of the CDD future is calculated, using analytical approximation formulas. Numerical examples are presented to indicate the accuracy of the method. The results show that our model performs better to predict CDD indices.
