Zinc deficiency is a common constraint for wheat production in the regions with limited precipitation,particularly in the regions with high levels of available phosphate （P） in soil.Two experiments were conducted us...Zinc deficiency is a common constraint for wheat production in the regions with limited precipitation,particularly in the regions with high levels of available phosphate （P） in soil.Two experiments were conducted using chelator-buffered nutrient solutions to characterize differences in tolerance to Zn deficiency among three winter wheat （Triticum aestivum L）.genotypes and to investigate the relationship between P and Zn nutrition in wheat species.Four indices,Zn efficiency,relative shoot-to-root ratio,total Zn uptake in shoot,and shoot dry weight were used to compare the tolerance to Zn deficiency among three wheat genotypes.The results indicated that the four indices could be used in breeding selection for Zn uptake-efficient genotypes.The genotype H6712 was the most tolerant to Zn deficient,followed by M19,and then X13.Specifically,H6712 had the highest Zn uptake efficiency among the three genotypes.The addition of P to the growth medium increased Zn uptake and translocation from roots to shoots.Total Zn content of the wheat plant was 43% higher with 0.6 mmol/L P treatment than that of control with 0 mmol /L P treatment.The Zn translocation ratios from roots to shoots were increased by 16% and 26% with 0.6 mmol/L P treatment and 3 mmol/L P treatment,respectively,compared with 0 mmol/L P treatment.In contrast,high Zn concentrations in the growth medium inhibited P translocation from roots to shoots,but the inhibitive effects were not strong.Sixty-six percent of P taken up by wheat plants was translocated to the wheat shoots at 0 μmol/L Zn treatment,while the percent was 60% at 3 μmol/L Zn treatment.The result may be due to the fact that the wheat plants need more P than Zn.展开更多
以乙二胺(EDA)还原氧化石墨烯(GO)制得一种吸附材料,即还原态氧化石墨烯(RGO)。采用批量平衡法研究了RGO对Zn(Ⅱ)的吸附动力学与热力学,利用Lagergren准一级及准二级动力学方程、Langmuir和Freundlich等温方程对实验数据进行了拟合分析...以乙二胺(EDA)还原氧化石墨烯(GO)制得一种吸附材料,即还原态氧化石墨烯(RGO)。采用批量平衡法研究了RGO对Zn(Ⅱ)的吸附动力学与热力学,利用Lagergren准一级及准二级动力学方程、Langmuir和Freundlich等温方程对实验数据进行了拟合分析。研究结果表明,Lagergren准二级吸附动力学模型能够较好地描述实验结果,表明该吸附过程以化学吸附为主。RGO的吸附在所研究的Zn(Ⅱ)浓度范围内更符合Langmuir等温吸附经验式,ΔH0=-21.60 k J/mol,吸附焓变小于零,表明该吸附为放热过程;吸附吉布斯自由能变化ΔG0为正值,表明该吸附是一个非自发的过程。展开更多
基金supported by National Natural Science Foundation of China (40971179 and 31071863) the New-Century Excellent Talent Program of the Education Ministry of China (NCET-06-0866)
文摘Zinc deficiency is a common constraint for wheat production in the regions with limited precipitation,particularly in the regions with high levels of available phosphate （P） in soil.Two experiments were conducted using chelator-buffered nutrient solutions to characterize differences in tolerance to Zn deficiency among three winter wheat （Triticum aestivum L）.genotypes and to investigate the relationship between P and Zn nutrition in wheat species.Four indices,Zn efficiency,relative shoot-to-root ratio,total Zn uptake in shoot,and shoot dry weight were used to compare the tolerance to Zn deficiency among three wheat genotypes.The results indicated that the four indices could be used in breeding selection for Zn uptake-efficient genotypes.The genotype H6712 was the most tolerant to Zn deficient,followed by M19,and then X13.Specifically,H6712 had the highest Zn uptake efficiency among the three genotypes.The addition of P to the growth medium increased Zn uptake and translocation from roots to shoots.Total Zn content of the wheat plant was 43% higher with 0.6 mmol/L P treatment than that of control with 0 mmol /L P treatment.The Zn translocation ratios from roots to shoots were increased by 16% and 26% with 0.6 mmol/L P treatment and 3 mmol/L P treatment,respectively,compared with 0 mmol/L P treatment.In contrast,high Zn concentrations in the growth medium inhibited P translocation from roots to shoots,but the inhibitive effects were not strong.Sixty-six percent of P taken up by wheat plants was translocated to the wheat shoots at 0 μmol/L Zn treatment,while the percent was 60% at 3 μmol/L Zn treatment.The result may be due to the fact that the wheat plants need more P than Zn.
文摘以乙二胺(EDA)还原氧化石墨烯(GO)制得一种吸附材料,即还原态氧化石墨烯(RGO)。采用批量平衡法研究了RGO对Zn(Ⅱ)的吸附动力学与热力学,利用Lagergren准一级及准二级动力学方程、Langmuir和Freundlich等温方程对实验数据进行了拟合分析。研究结果表明,Lagergren准二级吸附动力学模型能够较好地描述实验结果,表明该吸附过程以化学吸附为主。RGO的吸附在所研究的Zn(Ⅱ)浓度范围内更符合Langmuir等温吸附经验式,ΔH0=-21.60 k J/mol,吸附焓变小于零,表明该吸附为放热过程;吸附吉布斯自由能变化ΔG0为正值,表明该吸附是一个非自发的过程。
