目的基于近红外光谱(near infrared spectroscopy,NIRS)技术快速检测大豆中水分和粗脂肪含量。方法首先采集350~2500 nm光谱范围的大豆近红外光谱,采用光谱-理化值共生距离(sample set partitioning based on joint x-y distance,SPXY)...目的基于近红外光谱(near infrared spectroscopy,NIRS)技术快速检测大豆中水分和粗脂肪含量。方法首先采集350~2500 nm光谱范围的大豆近红外光谱,采用光谱-理化值共生距离(sample set partitioning based on joint x-y distance,SPXY)算法将大豆样本划分为校正集样本与测试集样本,然后对原始光谱分别采用多元散射校正、标准正态变量交换、归一化等9种方法进行预处理,最后使用偏最小二乘回归分析方法建立模型对样本进行定量分析。结果原始光谱经过多元散射校正后建立的偏最小二乘回归模型对水分的预测精度最高,其校正集和测试集的相关系数分别为0.8964和0.9055,均方根误差分别为0.4211和0.5933;原始光谱经过归一化处理后建立的偏最小二乘回归模型对粗脂肪的预测精度最高,其校正集和测试集的相关系数分别为0.9084和0.9295,均方根误差分别为0.6897和0.6462。结论近红外光谱结合预处理及偏最小二乘回归法,可以快速、准确的检测大豆水分和粗脂肪含量。展开更多
From the nonperturbative quantum electrodynamics theory, we derive the Landau-Dykhne formula which represents the quantum-mechanical formulation of the three-step model. These studies provide a basis for the classical...From the nonperturbative quantum electrodynamics theory, we derive the Landau-Dykhne formula which represents the quantum-mechanical formulation of the three-step model. These studies provide a basis for the classical-field approaches to high-order harmonic generation and justify some assumptions used in classical-field modelling.展开更多
By using the time-independent formal scattering theoretical approach,we develop a nonperturbative quantum electrodynamics theory to describe high-order harmonic generation(HHG).This theory recovers the semi-classical ...By using the time-independent formal scattering theoretical approach,we develop a nonperturbative quantum electrodynamics theory to describe high-order harmonic generation(HHG).This theory recovers the semi-classical interpretation of Corkum(Phys.Rev.Lett.71(1993)1994)and gives the same phenomenological cutoff law.The HHG emission rate is expressed as an analytic closed form.We also discuss the connection between HHG and the above threshold ionization from the scattering viewpoint.展开更多
Based on the nonperturbative quantum electrodynamics theory of high-order harmonic generation (HHG), we establish a direct connection between above-threshold ionization (ATI) and HHG. HHG can be described simply as an...Based on the nonperturbative quantum electrodynamics theory of high-order harmonic generation (HHG), we establish a direct connection between above-threshold ionization (ATI) and HHG. HHG can be described simply as an ATI followed by laser assisted recombination (LAR). The plateau reflects mainly the characteristic of LAR.展开更多
Maize seedlings were cultured in nickel or cadmium contaminated sand treated with α-naphthylacetic acid (NAA). The effeets of NAA on nickel and cadmium uptake in roots, shoots, and subcellular fractions (cell wall, n...Maize seedlings were cultured in nickel or cadmium contaminated sand treated with α-naphthylacetic acid (NAA). The effeets of NAA on nickel and cadmium uptake in roots, shoots, and subcellular fractions (cell wall, nuclei and remained parts of seedling cells) were determined. The data showed growth promotion when NAA was applied at low concentrations and inhibition at high concentrations. Uptake of nickel and cadmium content increased concurmntly in roots and shoots. In thesubcellular fraction, nickel and cadmium was greatest in the cell wall. The changes in growth had greatest cormlation Wtih nickel and cadmium content in the subeellular fraction.展开更多
文摘目的基于近红外光谱(near infrared spectroscopy,NIRS)技术快速检测大豆中水分和粗脂肪含量。方法首先采集350~2500 nm光谱范围的大豆近红外光谱,采用光谱-理化值共生距离(sample set partitioning based on joint x-y distance,SPXY)算法将大豆样本划分为校正集样本与测试集样本,然后对原始光谱分别采用多元散射校正、标准正态变量交换、归一化等9种方法进行预处理,最后使用偏最小二乘回归分析方法建立模型对样本进行定量分析。结果原始光谱经过多元散射校正后建立的偏最小二乘回归模型对水分的预测精度最高,其校正集和测试集的相关系数分别为0.8964和0.9055,均方根误差分别为0.4211和0.5933;原始光谱经过归一化处理后建立的偏最小二乘回归模型对粗脂肪的预测精度最高,其校正集和测试集的相关系数分别为0.9084和0.9295,均方根误差分别为0.6897和0.6462。结论近红外光谱结合预处理及偏最小二乘回归法,可以快速、准确的检测大豆水分和粗脂肪含量。
基金Supported by the Chinese Academy of Sciences,the National Natural Science Foundation of China under Grant Nos.69725010 and 69678008the Climbing Program of the National Ministry of Science and Technology of China.
文摘From the nonperturbative quantum electrodynamics theory, we derive the Landau-Dykhne formula which represents the quantum-mechanical formulation of the three-step model. These studies provide a basis for the classical-field approaches to high-order harmonic generation and justify some assumptions used in classical-field modelling.
基金Supported by the Chinese Academy of Sciences,the National Natural Science Foundation of China under Grant Nos.69725010,69678008,and the Climbing Program from the Chinese Commission of Science and Technology.
文摘By using the time-independent formal scattering theoretical approach,we develop a nonperturbative quantum electrodynamics theory to describe high-order harmonic generation(HHG).This theory recovers the semi-classical interpretation of Corkum(Phys.Rev.Lett.71(1993)1994)and gives the same phenomenological cutoff law.The HHG emission rate is expressed as an analytic closed form.We also discuss the connection between HHG and the above threshold ionization from the scattering viewpoint.
基金Supported by the Chinese Academy of Sciences,the National Natural Science Foundation of China under Grant Nos.69725010 and 69678008the Climbing Program of the Chinese Commission of Science and Technology。
文摘Based on the nonperturbative quantum electrodynamics theory of high-order harmonic generation (HHG), we establish a direct connection between above-threshold ionization (ATI) and HHG. HHG can be described simply as an ATI followed by laser assisted recombination (LAR). The plateau reflects mainly the characteristic of LAR.
文摘Maize seedlings were cultured in nickel or cadmium contaminated sand treated with α-naphthylacetic acid (NAA). The effeets of NAA on nickel and cadmium uptake in roots, shoots, and subcellular fractions (cell wall, nuclei and remained parts of seedling cells) were determined. The data showed growth promotion when NAA was applied at low concentrations and inhibition at high concentrations. Uptake of nickel and cadmium content increased concurmntly in roots and shoots. In thesubcellular fraction, nickel and cadmium was greatest in the cell wall. The changes in growth had greatest cormlation Wtih nickel and cadmium content in the subeellular fraction.
