传统光伏发电功率预测存在因气象因素特征提取不综合不精确而导致预测精度不高的问题.为了充分挖掘气象因素对光伏出力的影响,并有效利用深度学习技术在非线性拟合方面的优势,本文提出了一种基于气象因素充分挖掘的双向长短期记忆(Bi-di...传统光伏发电功率预测存在因气象因素特征提取不综合不精确而导致预测精度不高的问题.为了充分挖掘气象因素对光伏出力的影响,并有效利用深度学习技术在非线性拟合方面的优势,本文提出了一种基于气象因素充分挖掘的双向长短期记忆(Bi-directional Long Short Term Memory,BiLSTM)网络光伏发电短期功率预测方法.在对原始数据进行异常值及标准化处理的基础上,采用K近邻算法(K-Nearest Neighbor,KNN)在外界温度、湿度、压强等诸多气象因素中充分挖掘影响光伏出力的关键因素,重构多元数据序列,并在探索输入层时间步长、模型层数及每层维数等超参数的合理设置方案的基础上,构建BiLSTM网络模型,实现光伏发电短期功率的高精度预测.仿真结果表明,与KNN、深度信念网络(DBN)、BiLSTM、PCA-LSTM等经典方法比较,所提KNN-BiLSTM方法具有更高的预测精度.展开更多
Increasing zinc(Zn)concentration in wheat grain is important to minimize human dietary Zn deficiency.This study aimed to investigate the effect of foliar Zn and soil nitrogen(N)applications on the accumulation and dis...Increasing zinc(Zn)concentration in wheat grain is important to minimize human dietary Zn deficiency.This study aimed to investigate the effect of foliar Zn and soil nitrogen(N)applications on the accumulation and distribution of N and Zn in grain pearling fractions,N remobilization,and the relationships between nutrient concentration in the vegetative tissues and grain or its fractions in two cropping years in the North China Plain.The results showed a progressive decrease in N and Zn concentrations from the outer to the inner parts of grain,with most of the accumulation in the core endosperm.Foliar Zn application significantly increased N concentration in the pericarp,and soil N application increased N concentration in each grain fraction.Both treatments significantly increased core endosperm Zn concentration.Foliar Zn had no effect on grain N and Zn distribution.Soil N application made N concentrated in the aleurone,promoted Zn translocation to the core endosperm and also increased N remobilization and its efficiency from the shoot to the grain,but no improved contribution to grain was found.N concentration in grain and its fractions were positively correlated with N in vegetative organs at anthesis and maturity,while positive correlations were obtained between N concentration in the pericarp and progressive central area of the endosperm and Zn concentration in the core endosperm.Thus,foliar Zn and soil N applications effectively increased yield and N and Zn concentrations in the wheat grain,particularly in the endosperm,and could be promising strategies to address Zn deficiency.展开更多
文摘传统光伏发电功率预测存在因气象因素特征提取不综合不精确而导致预测精度不高的问题.为了充分挖掘气象因素对光伏出力的影响,并有效利用深度学习技术在非线性拟合方面的优势,本文提出了一种基于气象因素充分挖掘的双向长短期记忆(Bi-directional Long Short Term Memory,BiLSTM)网络光伏发电短期功率预测方法.在对原始数据进行异常值及标准化处理的基础上,采用K近邻算法(K-Nearest Neighbor,KNN)在外界温度、湿度、压强等诸多气象因素中充分挖掘影响光伏出力的关键因素,重构多元数据序列,并在探索输入层时间步长、模型层数及每层维数等超参数的合理设置方案的基础上,构建BiLSTM网络模型,实现光伏发电短期功率的高精度预测.仿真结果表明,与KNN、深度信念网络(DBN)、BiLSTM、PCA-LSTM等经典方法比较,所提KNN-BiLSTM方法具有更高的预测精度.
基金the National Key Research and Development Program of China(2018YFD0300707 and 2016YFD0300400)the Modern Wheat Industrial Technology System of Henan Province,China(S2010-01-G07).
文摘Increasing zinc(Zn)concentration in wheat grain is important to minimize human dietary Zn deficiency.This study aimed to investigate the effect of foliar Zn and soil nitrogen(N)applications on the accumulation and distribution of N and Zn in grain pearling fractions,N remobilization,and the relationships between nutrient concentration in the vegetative tissues and grain or its fractions in two cropping years in the North China Plain.The results showed a progressive decrease in N and Zn concentrations from the outer to the inner parts of grain,with most of the accumulation in the core endosperm.Foliar Zn application significantly increased N concentration in the pericarp,and soil N application increased N concentration in each grain fraction.Both treatments significantly increased core endosperm Zn concentration.Foliar Zn had no effect on grain N and Zn distribution.Soil N application made N concentrated in the aleurone,promoted Zn translocation to the core endosperm and also increased N remobilization and its efficiency from the shoot to the grain,but no improved contribution to grain was found.N concentration in grain and its fractions were positively correlated with N in vegetative organs at anthesis and maturity,while positive correlations were obtained between N concentration in the pericarp and progressive central area of the endosperm and Zn concentration in the core endosperm.Thus,foliar Zn and soil N applications effectively increased yield and N and Zn concentrations in the wheat grain,particularly in the endosperm,and could be promising strategies to address Zn deficiency.
