中国长江流域冬麦区小麦品种试验精确度回溯分析     

张笑晴  吴宏亚  伍玲  霍珊珊  汪尊杰  朱华忠 《麦类作物学报》2024,44(1):119-126

为全面评价长江流域小麦品种区域试验精确度的发展水平,分析了2011—2021年度中国长江流域冬麦区单年单点和一年多点小麦区域试验的试验精确度和品种比较精确度,对产量、穗数、穗粒数、千粒重、生育期、株高、基本苗和最高茎数等性状的试验精确度差异进行了比较。结果表明,长江流域冬麦区单年单点品种试验精确度较好,试验误差变异系数(CEV)在5%和10%以下的试点数占比分别在60%和95%以上,但品种比较精确度(RLSD_0.05)在3%以下的试验比例不到10%,长江上游和中下游单点品种试验RLSD_0.05在10%以下的试点数分别占比约60%和90%。一年多点区域试验精确度和品种比较精确度显著优于单年单点试验,上游和中下游试验平均CEV分别在8%和5%以下。采用试点固定模型时,长江上游和中下游试验平均RLSD_0.05分别为2.19%和1.49%,符合国家小麦品种审定标准对品种比较精确度的要求;但采用试点随机模型时,小麦品种试验尚无法鉴别出品种间3%的产量差异。试验对生育期、株高、基本苗、千粒重和穗数的RLSD_0.05优于产量性状,而最高茎数和穗粒数的RLSD_0.05较低。  相似文献   

Amino acid profile of the quinoa (Chenopodium quinoa Willd.) using near infrared spectroscopy and chemometric techniques     

Olga Escuredo  M. Inmaculada González Martín  Guillermo Wells Moncada  Susana Fischer  José Miguel Hernández Hierro 《Journal of Cereal Science》2014

The high content of amino acids of the quinoa, especially essential amino acids (higher than other cereals) makes a food increasingly demanded by consumers. A total of twelve amino acids (arginine, cystine, isoleucine, leucine, lysine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine and valine) were analyzed in quinoa samples from Chile by near infrared spectroscopy (NIR) with direct application to the samples of a remote fiber-optic reflectance probe. The calibration results using modified partial least squares (MPLS) regression satisfactorily allowed the determination of the concentrations of this amino acid group with high multiple correlation coefficients (RSQ = 0.97–0.71) and low standard prediction errors (SEPC = 0.07–0.20). The prediction capacity (RPD) for the arginine, the cystine, the isoleucine, the lysine, the serine, the threonine, the tryptophan, the tyrosine and the valine ranged between 2.6 and 5.2, for the rest of amino acids were higher to 1.8, indicating that the NIRS equations obtained were applicable to unknown samples. It has confirmed that NIRS technology is a method that may be useful to replace the traditional methods for routine analysis of some amino acids.  相似文献   

Performance of field-scale lab vs in situ visible/near- and mid-infrared spectroscopy for estimation of soil properties     

Isabel Greenberg  Michael Seidel  Michael Vohland  Bernard Ludwig 《European Journal of Soil Science》2022,73(1):e13180

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基于偏最小二乘法的武汉市生态足迹模型及驱动力研究     

尤艳丽  周敬宣  李湘梅 《湖北农业科学》2014,53(19):4751-4756

选取表征社会经济发展的重要指标建立了社会经济系统指标,在对武汉市1990~2012年生态足迹计算结果基础上,应用偏最小二乘法构建了武汉市生态足迹回归模型,并分阶段对其生态足迹驱动力进行了分析。结果表明,1990~2010年间武汉市生态足迹呈上升趋势,主要驱动力为城市化率、人口规模及经济水平的提高;2010年武汉市生态足迹达到高峰值,为2 335.537 hm2,人均生态足迹为2.8 hm2/人,随后生态足迹与GDP及人均可支配收入于2011年开始呈现负相关性,生态足迹与GDP开始呈现倒“U”型转折点,人均生态足迹于2012年下降为2.43 hm2/人;“十二五”期间,武汉市高新技术产业所占比例及第三产业所占比例的增加,能源消耗总量及万元工业能耗的下降,对减缓人口对自然资源的依赖发挥了重要的作用。  相似文献   

基于近红外光谱苗期玉米叶片叶绿素含量的无损检测方法   总被引：1，自引：0，他引：1  

翟哲  李伟凯 《黑龙江八一农垦大学学报》2014,(2):82-85

试验以42片未经处理的苗期玉米叶片为试材,采用近红外光谱检测技术和SNV+Detrending的预处理方法,应用偏最小二乘回归分析方法建立定量分析模型,通过测定近红外光谱图,研究3 300~10 000 cm-1范围内苗期玉米叶片的光谱特性。结果表明,测定苗期玉米叶片叶绿素含量的决定系数R2为0.989,残差均方根RMSE为0.047,采用近红外光谱快速检测苗期玉米叶片叶绿素含量是可行的。  相似文献   

一种Logistic模型参数估计的新方法及应用     

赵红  王增辉 《湖南农业大学学报(自然科学版)》2014,(3):103-105

介绍了logistic曲线参数估计的一种新方法,它是利用三次样条插值函数求导代替logistic曲线在这一点的导数值,进而利用最小二乘法得出参数的估计值,通过实例分析表明本文提出的方法比一般的三点法估计的参数值k再用线性化方法估计的参数值b,c,拟合精度更高.  相似文献   

Hyper-spectral estimation of wheat biomass after alleviating of soil effects on spectra by non-negative matrix factorization     

《European Journal of Agronomy》2017

Hyper-spectral technology has been proven to be an effective method for the fast and non-destructive monitoring of crop biomass. However, the biomass estimation accuracy of this method is limited due to the effects of background factors, such as soils and water. In this study, a spectral separation method, non-negative matrix factorization (NMF), was proposed to alleviate the effects of soil on spectra. With the application of the NMF method, pure vegetation spectra were extracted from the field-observed spectra of wheat canopy, which were collected in four growing seasons from the tillering to the booting stages of wheat. Then, prediction models of wheat biomass (WB) were established and validated using the extracted spectra with the partial least squares regression (PLSR) method. The results showed that the NMF method could effectively separate the vegetation spectra from the mixed canopy spectra. Based on the extracted vegetation spectra, the WB prediction accuracy could be greatly improved with an increase of 31.7% for the R²_p and an increase of 46.6% for the ratio of performance to deviation (RPD) as compared to the original spectra, indicating that the NMF method could significantly improve the performance of the WB prediction model. This method has potential application in the estimation of biomass using remote sensing technology.  相似文献   

基于模糊控制的牵引电机冷却风机变频节能控制系统     

邓文慧  桂卫华  喻寿益 《湖南农业大学学报(自然科学版)》2012,(4):1-6

介绍了一种求解旅行商问题的新算法“最小调整法”，给出了该算法求解旅行商问题的具体步骤以及有效性证明，对算法的复杂性及近似程度进行了分析.最后通过典型算例进行了检验说明.与经典算法相比，新算法体现了简单易行的特点，对求解旅行商问题具有一定的启发意义.  相似文献   

Optimization potential for perception-oriented appearance classification by simulated sawing of computed tomography-scanned logs of Norway spruce     

《Wood material science & engineering》2013,8(4):319-334

Abstract

Wood, as a natural material, has favourable properties in both technical and aesthetic aspects. Due to its inherent variability, production of high-quality sawn timber demands adequate control of log conversion, which is feasible with computed tomography (CT) log scanning. Existing appearance grading rules for sawn timber might not fully reflect people's visual perception of wood surfaces, and therefore, an alternative, more perception-oriented appearance classification could be beneficial. An appearance classification of sawn timber based on partial least squares discriminant analysis (PLS-DA) of knot-pattern variables was developed and tested. Knot-pattern variables derived from images of board faces were used in training PLS-DA models against an initial classification of the board faces previously established by aid of cluster analysis. Virtual board faces obtained from simulated breakdown of 57 CT-scanned Norway spruce logs were graded according to the developed classification. Visual assessment of the grading results indicated that the classification was largely consistent with human perception of board appearance. An initial estimation of the potential to optimize log rotation, based on CT data, for the established appearance grades was derived from the simulations. Considerable potential to increase the yield of a desired appearance grade, compared to conventional log positioning, was observed.  相似文献   

基于农业机械替代作用的农业劳动力需求预测模型   总被引：1，自引：1，他引：0  

刘清峰  刘金兰 《中国农机化》2006,(1):41-43

农业机械对农业劳动力具有替代作用,在不考虑其他因素对劳动力影响的前提下,我国农业劳动力占总人口的比重与农业机械拥有量呈反相的线性相关关系。检验结果表明,用最小二乘回归法建立的劳动力预测模型是可靠的。  相似文献