The accumulation of citric acid and associated correlative strain indexes were investigated in the seedlings of Puccinellia tenuiflora (Griseb.) Scribn. et Merr. stressed with 0-175 mmol/L Na 2CO 3. The results ...The accumulation of citric acid and associated correlative strain indexes were investigated in the seedlings of Puccinellia tenuiflora (Griseb.) Scribn. et Merr. stressed with 0-175 mmol/L Na 2CO 3. The results showed that the citric acid accumulation is a specific physiological respond of this plant to alkali_stress. On the contrary, the citric acid content decreased slightly in this plant stressed with 0-400 mmol/L neutral salt NaCl. The accumulation of citric acid increased with increasing strength of alkali_stress, the citric acid content increased gently when the strength was lower than 100 mmol/L Na 2CO 3, but increased obviously when the strength was higher than 100 mmol/L Na 2CO 3. The citric acid rapidly accumulated at early alkali_stress, an obvious raise can be mensurated after 4 h. About 48 h after treatment, the amount of citric acid accumulated nearly reached the maximum. In various parts of P. tenuiflora seedlings alkali_stressed for 144 h, the order of citric acid content from high to low is: old leaf, mature leaf, old leaf sheath, young leaf sheath, young stem, old stem, and young leaf. In the mature leaf, the citric acid content gradually increased with increasing strength of alkali_stress, while the citric acid content increased sharply in old leaf and sheath just for strength higher than 125 mmol/L. There was little change of citric acid content in stem, but no change in young leaf. The results of the experiment showed that citric acid was outstanding among accumulated organic acid caused by alkali_stress. The contribution of other organic acids was negligible.展开更多
用0～200 m m ol/L的碱性盐Na2CO3 对星星草进行胁迫处理,跟踪调查星星草体内脯氨酸含量,柠檬酸含量等主要胁变指标随胁迫时间的变化。结果表明,Na2CO3 胁迫处理后星星草植株体内的有机酸、柠檬酸、脯氨酸、Na+ 等物质含量均随胁迫时间...用0～200 m m ol/L的碱性盐Na2CO3 对星星草进行胁迫处理,跟踪调查星星草体内脯氨酸含量,柠檬酸含量等主要胁变指标随胁迫时间的变化。结果表明,Na2CO3 胁迫处理后星星草植株体内的有机酸、柠檬酸、脯氨酸、Na+ 等物质含量均随胁迫时间延长而迅速上升,含水量、K+ 含量、K+ /Na+ 则随胁迫时间延长而迅速下降。各项胁变反应多持续发展到胁迫后48 h 左右达最大程度,而后变化趋于平缓。各项胁变值随胁迫时间而变化的幅度因胁强增大而增大,但引发不同胁变反应所需要的胁强阈值不同,脯氨酸在50 m m ol/L时即有明显积累而柠檬酸则需要125 m m ol/L时才开始明显积累。展开更多
The oxidation process of low-grade vanadium slag in the presence of Na2CO3 was investigated by XRD,SEM/EDS and TG-DSC techniques.The results show that the vanadium slag is oxidized in a temperature range from 273 to 7...The oxidation process of low-grade vanadium slag in the presence of Na2CO3 was investigated by XRD,SEM/EDS and TG-DSC techniques.The results show that the vanadium slag is oxidized in a temperature range from 273 to 700 °C.Olivine phases and spinel phases are completely decomposed at 500 and 600 °C,respectively.Most of water-soluble sodium vanadates are formed between 500 and 600 °C.When roasting temperature reaches above 700 °C,the vanadium-rich phases of sodium vanadates can be obviously observed.However,at temperature above 800 °C,the samples are sintered.Most of the vanadium is enwrapped by glassy phase compounds which lead to the decrease of the leaching rate of vanadium.At the same time,the effect of roasting temperature on extraction of vanadium and characterization of leach residues were discussed.展开更多
文摘The accumulation of citric acid and associated correlative strain indexes were investigated in the seedlings of Puccinellia tenuiflora (Griseb.) Scribn. et Merr. stressed with 0-175 mmol/L Na 2CO 3. The results showed that the citric acid accumulation is a specific physiological respond of this plant to alkali_stress. On the contrary, the citric acid content decreased slightly in this plant stressed with 0-400 mmol/L neutral salt NaCl. The accumulation of citric acid increased with increasing strength of alkali_stress, the citric acid content increased gently when the strength was lower than 100 mmol/L Na 2CO 3, but increased obviously when the strength was higher than 100 mmol/L Na 2CO 3. The citric acid rapidly accumulated at early alkali_stress, an obvious raise can be mensurated after 4 h. About 48 h after treatment, the amount of citric acid accumulated nearly reached the maximum. In various parts of P. tenuiflora seedlings alkali_stressed for 144 h, the order of citric acid content from high to low is: old leaf, mature leaf, old leaf sheath, young leaf sheath, young stem, old stem, and young leaf. In the mature leaf, the citric acid content gradually increased with increasing strength of alkali_stress, while the citric acid content increased sharply in old leaf and sheath just for strength higher than 125 mmol/L. There was little change of citric acid content in stem, but no change in young leaf. The results of the experiment showed that citric acid was outstanding among accumulated organic acid caused by alkali_stress. The contribution of other organic acids was negligible.
文摘用0～200 m m ol/L的碱性盐Na2CO3 对星星草进行胁迫处理,跟踪调查星星草体内脯氨酸含量,柠檬酸含量等主要胁变指标随胁迫时间的变化。结果表明,Na2CO3 胁迫处理后星星草植株体内的有机酸、柠檬酸、脯氨酸、Na+ 等物质含量均随胁迫时间延长而迅速上升,含水量、K+ 含量、K+ /Na+ 则随胁迫时间延长而迅速下降。各项胁变反应多持续发展到胁迫后48 h 左右达最大程度,而后变化趋于平缓。各项胁变值随胁迫时间而变化的幅度因胁强增大而增大,但引发不同胁变反应所需要的胁强阈值不同,脯氨酸在50 m m ol/L时即有明显积累而柠檬酸则需要125 m m ol/L时才开始明显积累。
基金Project (2008AA031104) supported by the National High-tech Research and Development Program of China Project (2010063003) supported by the Sharing Fund of Large-scale Equipment of Chongqing University,China
文摘The oxidation process of low-grade vanadium slag in the presence of Na2CO3 was investigated by XRD,SEM/EDS and TG-DSC techniques.The results show that the vanadium slag is oxidized in a temperature range from 273 to 700 °C.Olivine phases and spinel phases are completely decomposed at 500 and 600 °C,respectively.Most of water-soluble sodium vanadates are formed between 500 and 600 °C.When roasting temperature reaches above 700 °C,the vanadium-rich phases of sodium vanadates can be obviously observed.However,at temperature above 800 °C,the samples are sintered.Most of the vanadium is enwrapped by glassy phase compounds which lead to the decrease of the leaching rate of vanadium.At the same time,the effect of roasting temperature on extraction of vanadium and characterization of leach residues were discussed.
