The stability of porphyra-334 in solutions of different pH values at different temperatures was studied. In high acidic conditions, below pH 3, the absorption maximum, λ max, of porphyra-334 shows hypsochromic shift ...The stability of porphyra-334 in solutions of different pH values at different temperatures was studied. In high acidic conditions, below pH 3, the absorption maximum, λ max, of porphyra-334 shows hypsochromic shift towards lower wavelength and the absorbance also has a light decrease. In high alkaline conditions of over pH 12, the absorbance of porphyra-334 decreases and an unknown compound with a peak maximum at 225 nm appears. The peak height of the unknown compound increases with the decrease of absorbance of porphyra-334. This might be related to the decomposition of porphyra-334. At room temperature, porphyra-334 solutions, except high alkaline solutions, are stable. Increasing the temperature, especially higher than 60℃, promotes the decomposition of porphyra-334 and causes the absorbance decrease both in basic and acidic solutions.展开更多
Using 2-3 weeks kid abomasums as materials, the ultrasound intensity, extracting time, NaCl concentration and pH valuein extracting solution and ratio of abomasums to extracting solution were studied by ultrasonic met...Using 2-3 weeks kid abomasums as materials, the ultrasound intensity, extracting time, NaCl concentration and pH valuein extracting solution and ratio of abomasums to extracting solution were studied by ultrasonic method. The resultsshowed that the main factor affecting kid rennet activity during extraction was ultrasound intensity, and then NaClconcentration, extracting time and ratio of abomasums to extracting solution in order. Kid rennet activity reached peakwith ultrasound intensity 30 W cm-2, extraction time 40 min, NaCl concentration 8%, pH value 3.0, ratio of abomasums toextracting solution 1:15.展开更多
Fermentation processes were studied, with an aim of improving the quality of Chinesejujube wine. Results showed the quality of the wine made from fresh Chinese jujube anddried Chinese jujube were similar, but wine mad...Fermentation processes were studied, with an aim of improving the quality of Chinesejujube wine. Results showed the quality of the wine made from fresh Chinese jujube anddried Chinese jujube were similar, but wine made from excessively dried Chinese jujubeshowed decreased quality. The reducing sugar content in Chinese jujube juice extractedby pectic enzymes was higher than the reducing sugar content extracted by hot water,however, methanol content in wine extracted by pectic enzymes also increased. Thereforethe hot water extraction method is recommended for fermentation of Chinese jujube wine.Fermentation using vacuum concentrated Chinese jujube juice was more effective than thatusing filtered juice readjusted to 20% soluble solid content (SSC) with sucrose orglucose. The inoculation of 0.3% Saccharomyces ellipsodieus Strain was suitable forfermentation of Chinese jujube wine. Fermentation was carried out at 21-25℃. Theconcentration of SO2 in wine affected fermentation time and the optimum additional amountwas 40 mg L-1. Post fermentation storage in oak barrel improved the quality of Chinesejujube wine, as did 4.5% diatomite filtration.展开更多
A method of estimating the critical rate of temperature rise for the thermal explosion of first order autocatalytic decomposition reaction systems by using non-isothermal DSC is presented. The information was obtained...A method of estimating the critical rate of temperature rise for the thermal explosion of first order autocatalytic decomposition reaction systems by using non-isothermal DSC is presented. The information was obtained on the increasing rate of temperature for the first order autocatalytic decomposition of nitrocellulose containing 13.86% nitrogen converting into the thermal explosion.展开更多
基金supported by the Natural Science Foundation of Qingdao(No.04-2-JZ-110).
文摘The stability of porphyra-334 in solutions of different pH values at different temperatures was studied. In high acidic conditions, below pH 3, the absorption maximum, λ max, of porphyra-334 shows hypsochromic shift towards lower wavelength and the absorbance also has a light decrease. In high alkaline conditions of over pH 12, the absorbance of porphyra-334 decreases and an unknown compound with a peak maximum at 225 nm appears. The peak height of the unknown compound increases with the decrease of absorbance of porphyra-334. This might be related to the decomposition of porphyra-334. At room temperature, porphyra-334 solutions, except high alkaline solutions, are stable. Increasing the temperature, especially higher than 60℃, promotes the decomposition of porphyra-334 and causes the absorbance decrease both in basic and acidic solutions.
基金The study was supported by Natural Science Founda—tion of Shaanxi Province of China (2003C134)．
文摘Using 2-3 weeks kid abomasums as materials, the ultrasound intensity, extracting time, NaCl concentration and pH valuein extracting solution and ratio of abomasums to extracting solution were studied by ultrasonic method. The resultsshowed that the main factor affecting kid rennet activity during extraction was ultrasound intensity, and then NaClconcentration, extracting time and ratio of abomasums to extracting solution in order. Kid rennet activity reached peakwith ultrasound intensity 30 W cm-2, extraction time 40 min, NaCl concentration 8%, pH value 3.0, ratio of abomasums toextracting solution 1:15.
文摘Fermentation processes were studied, with an aim of improving the quality of Chinesejujube wine. Results showed the quality of the wine made from fresh Chinese jujube anddried Chinese jujube were similar, but wine made from excessively dried Chinese jujubeshowed decreased quality. The reducing sugar content in Chinese jujube juice extractedby pectic enzymes was higher than the reducing sugar content extracted by hot water,however, methanol content in wine extracted by pectic enzymes also increased. Thereforethe hot water extraction method is recommended for fermentation of Chinese jujube wine.Fermentation using vacuum concentrated Chinese jujube juice was more effective than thatusing filtered juice readjusted to 20% soluble solid content (SSC) with sucrose orglucose. The inoculation of 0.3% Saccharomyces ellipsodieus Strain was suitable forfermentation of Chinese jujube wine. Fermentation was carried out at 21-25℃. Theconcentration of SO2 in wine affected fermentation time and the optimum additional amountwas 40 mg L-1. Post fermentation storage in oak barrel improved the quality of Chinesejujube wine, as did 4.5% diatomite filtration.
基金Supported by the Science and Technology Foundation of Shaanxi Key L aboratory of Physico- Inorganic Chemistry(No.2 9- 3,2 0 0 1) and the Science and Technology Foundation of Propellant and Explosive Combustion of China(No.5 14 5 5 0 10 1)
文摘A method of estimating the critical rate of temperature rise for the thermal explosion of first order autocatalytic decomposition reaction systems by using non-isothermal DSC is presented. The information was obtained on the increasing rate of temperature for the first order autocatalytic decomposition of nitrocellulose containing 13.86% nitrogen converting into the thermal explosion.
