The rice Dongfu 159 was used for the potting experiment to simulate soil cadmium(Cd)stress,and four silicon preparations,Si-50-G and Si-60-G at a concentration of 0.20%and Si-T-G and Si-E-G at a concentration of 0.50%...The rice Dongfu 159 was used for the potting experiment to simulate soil cadmium(Cd)stress,and four silicon preparations,Si-50-G and Si-60-G at a concentration of 0.20%and Si-T-G and Si-E-G at a concentration of 0.50%,were applied at the tillering stage and booting stage of rice,respectively.The cadmium content,root vitality,root malondialdehyde(MDA)content,and antioxidant enzyme activity of each part of rice plants were determined,in order to provide a theoretical reference for exploring the mechanism of silicon fertilizer on the mitigation of Cd-stressed plants.The results showed that under the condition of cadmium stress,silicon application could significantly increase the root vitality and antioxidant enzyme activity,reduce the content of MDA,and reduce the accumulation of cadmium in various parts of rice.The treatment of Si-T-G applied at the tillering stage was the most effective in increasing the root vitality of rice,which was significantly increased by 63.00%compared with the CK.The treatment of Si-50-G applied at the stage of booting was the most effective in reducing MDA content of rice roots,which was significantly reduced by 30.16%compared with the CK.The treatment of Si-60-G applied at the stage of booting was the most effective in increasing the root superoxide dismutase(SOD)activity,which was significantly increased by 39.36%compared with the CK.The treatment of Si-60-G applied at the tillering stage was the most effective in increasing the root peroxidase(POD)and catalase(CAT)activities,which were significantly increased by 64.66%and 51.52%,respectively,compared with the CK.The treatment of Si-T-G applied at the tillering stage was the most effective in reducing Cd content of rice roots,stems and grains,which were significantly reduced by 39.53%,61.19%and 43.41%,respectively,compared with the CK,and the treatment of Si-60-G was the most effective in reducing Cd content of leaves,which was significantly reduced by 53.40%compared with the CK.展开更多
针对轧辊偏心信号是混杂在各种随机干扰中含有多次谐波的复杂高频周期信号,以及FFT(Fast Fourier Transform)法对轧辊偏心信号分析的局限性,研究了一种基于四阶累积量的Root-MUSIC(Multiple Signal Classification)法和Prony法相结合的...针对轧辊偏心信号是混杂在各种随机干扰中含有多次谐波的复杂高频周期信号,以及FFT(Fast Fourier Transform)法对轧辊偏心信号分析的局限性,研究了一种基于四阶累积量的Root-MUSIC(Multiple Signal Classification)法和Prony法相结合的轧辊偏心信号估计新方法.利用基于四阶累积量的Root-MUSIC法准确估计出偏心谐波的频率及谐波的个数,同时由Root-MUSIC求得的根直接使用Prony方法估计出偏心信号的各次谐波幅值和相位.仿真结果和实验结果也验证了结合方法的可行性和有效性,在信噪比较低的情况下仍具有较高的频谱分辨率和估计精度,能准确地同时估计出偏心谐波的频率、幅值及相位,尤其在频率分辨率和抗噪声上具有FFT法无法比拟的优越性.展开更多
基金Supported by the National Natural Science Foundation of China(31340032)。
文摘The rice Dongfu 159 was used for the potting experiment to simulate soil cadmium(Cd)stress,and four silicon preparations,Si-50-G and Si-60-G at a concentration of 0.20%and Si-T-G and Si-E-G at a concentration of 0.50%,were applied at the tillering stage and booting stage of rice,respectively.The cadmium content,root vitality,root malondialdehyde(MDA)content,and antioxidant enzyme activity of each part of rice plants were determined,in order to provide a theoretical reference for exploring the mechanism of silicon fertilizer on the mitigation of Cd-stressed plants.The results showed that under the condition of cadmium stress,silicon application could significantly increase the root vitality and antioxidant enzyme activity,reduce the content of MDA,and reduce the accumulation of cadmium in various parts of rice.The treatment of Si-T-G applied at the tillering stage was the most effective in increasing the root vitality of rice,which was significantly increased by 63.00%compared with the CK.The treatment of Si-50-G applied at the stage of booting was the most effective in reducing MDA content of rice roots,which was significantly reduced by 30.16%compared with the CK.The treatment of Si-60-G applied at the stage of booting was the most effective in increasing the root superoxide dismutase(SOD)activity,which was significantly increased by 39.36%compared with the CK.The treatment of Si-60-G applied at the tillering stage was the most effective in increasing the root peroxidase(POD)and catalase(CAT)activities,which were significantly increased by 64.66%and 51.52%,respectively,compared with the CK.The treatment of Si-T-G applied at the tillering stage was the most effective in reducing Cd content of rice roots,stems and grains,which were significantly reduced by 39.53%,61.19%and 43.41%,respectively,compared with the CK,and the treatment of Si-60-G was the most effective in reducing Cd content of leaves,which was significantly reduced by 53.40%compared with the CK.
文摘针对轧辊偏心信号是混杂在各种随机干扰中含有多次谐波的复杂高频周期信号,以及FFT(Fast Fourier Transform)法对轧辊偏心信号分析的局限性,研究了一种基于四阶累积量的Root-MUSIC(Multiple Signal Classification)法和Prony法相结合的轧辊偏心信号估计新方法.利用基于四阶累积量的Root-MUSIC法准确估计出偏心谐波的频率及谐波的个数,同时由Root-MUSIC求得的根直接使用Prony方法估计出偏心信号的各次谐波幅值和相位.仿真结果和实验结果也验证了结合方法的可行性和有效性,在信噪比较低的情况下仍具有较高的频谱分辨率和估计精度,能准确地同时估计出偏心谐波的频率、幅值及相位,尤其在频率分辨率和抗噪声上具有FFT法无法比拟的优越性.
