基于高光谱成像技术的柑橘缺陷无损检测

应用高光谱成像技术无损检测柑橘的缺陷。选取蒂腐、黑斑、褐腐、结痂缺陷果和正常果各30个,提取并分析了5类果皮感兴趣区域光谱曲线并结合主成分分析法确定2个最佳波长(615nm和680nm),然后基于特征波长作主成分分析,选取第2主成分作为分类识别图像,提出采用特征波长主成分分析法与波段比算法相结合的方法,识别率达到94%。试验结果表明,高光谱成像技术可以有效地对带有蒂腐、黑斑、褐腐、结痂缺陷的柑橘进行分类识别。     

基于高光谱成像和Att-BiGRU-RNN的柑橘病叶分类

为实现对柑橘叶片病虫药害种类的快速精准识别,针对多种类柑橘病叶设计一种融合注意力机制(Attention mechanism)的双向门控循环单元-循环神经网络(Attention-bidirectional gate recurrent unit-recurrent nural network, Att-BiGRU-RNN)分类模型。该模型在编解码模块分别采用BiGRU和RNN结构,能够利用高光谱数据前后波段光谱信息的关联性,有效提取光谱信息的深层特征;根据不同波段光谱信息的差异性引入注意力机制动态分配权重信息,提高重要光谱特征对分类模型的贡献率,提升模型的分类准确率。获取6类柑橘叶片高光谱信息,构建实验样本集,利用Att-BiGRU-RNN、VGG16、SVM和XGBoost分别建立柑橘病叶分类模型,Att-BiGRU-RNN模型总体分类准确率(Overall accuracy, OA)平均可达98.21%,相较于其他3种模型分别提高4.71、10.95、3.89个百分点,对光谱曲线重合度高的除草剂危害和煤烟病叶片的分类准确率有显著提升。实验结果表明,深度学习方法可有效利用高光谱不同...     

马铃薯叶片早疫病的高光谱识别研究

为实现马铃薯叶片早疫病的快速识别,达到尽早防治的目的,利用高光谱成像系统连续4天采集375~1018nm波段内的健康和染病马铃薯叶片的高光谱数据信息,并用ENVI软件提取感兴趣区域的光谱反射率平均值。分别建立基于全光谱(full spectrum,FS)、连续投影算法(SPA)和载荷系数法(x-LW)提取的特征波长的BP网络和LS-SVM识别模型,其中FS-BP、SPA-BP、x-LW-BP模型中预测集识别率分别为100%、100%、98.33%,LS-SVM模型的预测集识别率均为100%;SPA和x-LW提取的特征波长个数均仅占全波长的1.47%,大大简化了模型,提高了运算速率。实验表明:应用高光谱成像技术可以快速、准确地识别出马铃薯叶片早疫病,且SPA和x-LW可以作为特征波长提取的有效方法,为田间马铃薯早疫病的在线实时检测仪器的开发提供理论依据。     

基于近红外高光谱的梨叶片炭疽病与黑斑病识别

针对梨炭疽病和黑斑病发病症状很相似,难以区分,导致实际生产中不便对症施药的问题,以砀山酥梨叶片为研究对象,探究利用高光谱技术来识别梨叶片炭疽病与黑斑病的可行性.首先,运用高光谱成像系统采集砀山酥梨正常叶片、炭疽病叶片和黑斑病叶片的高光谱图像,提取图像的平均光谱反射率.采用多元散射校正法(Multiplicative s...     

农业自动化喷雾机械标靶害虫自动识别系统的研究

农业喷雾对象的识别和定位是农业自动化喷雾机械研究中的核心技术之一。对病虫害甘蓝进行精准喷洒农药,实现病虫害准确自动识别成为关键。为此,利用机器视觉的欧氏距离甘蓝夜蛾虫害自动识别检测系统,结合由Qualityspec光谱仪组成的光谱成像系统,对甘蓝正常叶片和遭受甘蓝夜蛾虫害的甘蓝叶片的颜色特征和光谱特征进行分析,并采用机器视觉分割阈值选取中的Otsu算法和自适应波段选择方法提取出了颜色差异的最佳几何阈值和两种叶片的特征波段。试验结果表明:综合机器视觉和光谱技术能够实现甘蓝夜蛾虫害的自动且准确的识别,准确率可达94%。因此,建立机器视觉和光谱技术综合识别体系,可为农作物病虫害自动防治喷雾机器人的研制奠定基础,以达到农作物病虫害实时识别和及时治理的目的。     

基于高光谱图像技术预测苹果大小

以新疆红富士苹果为研究对象,探讨应用高光谱图像技术和最小外接矩形法预测其大小的研究方法。提取苹果高光谱图像中可见红色区域受色度影响较小的713nm以及近红外区域793和852nm的3个波长图像,做双波段比运算处理。比较所得双波段比图像可知,852/713双波段比图像中背景和前景灰度对比度最大。对该图像做阈值分割以及形态闭运算去除果梗区域,使用8邻接边界跟踪法得到二值图像的轮廓坐标序列,采用最小外接矩形法求苹果的大小,与实测值建立回归方程。结果表明,基于高光谱图像技术采用波段比算法,结合最小外接矩形法,能够有效地检测苹果大小,预测值与实际值最大绝对误差为3.06mm,均方根误差为1.21mm。     

番茄叶片早疫病近红外高光谱成像检测技术

提出了基于格拉姆斯密特(MGS)模型和贝叶斯罗蒂斯克回归(BlogReg)的近红外高光谱成像技术检测番茄叶片早疫病的方法。利用高光谱图像采集系统获取波长874~1 734 nm范围内70个染病和80个健康番茄叶片的高光谱图像,选取染病和健康叶片30像素×30像素感兴趣区域的光谱反射率。建立了番茄叶片早疫病的最小二乘-支持向量机(LS-SVM)识别模型,再通过MGS和BlogReg提取特征波长(EW),分别得到5个(911、1 409、1 511、1609、1 656 nm)和9个(901、905、908、915、918、1 123、1 305、1 460、1 680 nm)特征波长,并建立EW-LS-SVM和EWLDA模型。在所有模型中,建模集的正确识别率为93%~98%,预测集的正确识别率为96%~100%。结果表明,近红外高光谱成像技术检测番茄叶片早疫病是可行的,MGS和BlogReg都是有效的特征波长提取方法。     

基于无人机高光谱影像的水稻叶片磷素含量估算

为快速获取水稻叶片磷素含量信息,采用无人机搭载高光谱成像仪获取水稻冠层高光谱影像,并采样检测叶片磷素含量(质量分数)(Leaf phosphorus content,LPC)。分析了水稻LPC在无人机高光谱影像上的光谱特征,使用连续投影算法提取对磷素敏感的特征波长,通过任意波段组合构建并筛选与磷素高度相关的光谱指数,基于特征波长反射率和光谱指数建立水稻LPC的估算模型,利用最佳模型对高光谱影像进行反演填图,得到LPC空间分布信息。结果表明:全生育期内LPC与462～718 nm范围内光谱反射率显著负相关,负相关最大处相关系数达到-0.902; LPC的特征波长为670、706、722、846 nm,基于特征波长、使用偏最小二乘回归建立的LPC估算模型精度最高,验证R²达到0.925,RMSE为0.027%;在任意波段组合构建的3种类型的光谱指数中,NDSI(R₄₉₈,R₆₀₆)、RSI(R₄₉₈,R₆₀₆)和DSI(R₄₉₈,R₅₈₆...     

镉胁迫下菊苣叶片原位高光谱响应特征与定量监测研究

探究镉胁迫下菊苣叶片高光谱响应特征,以实现基于叶片原位高光谱技术的作物镉胁迫快捷、精准监测。采用室内水培实验,供试品种为"欧洲菊苣"、"美洲菊苣"和"黔育一号",设置0、5、10、25、50、100、200μmol/L共7个镉胁迫梯度,于菊苣苗期测试叶片镉质量比及其原位高光谱反射率。分别利用逐步回归(SWR)、主成分回归(PCR)和偏最小二乘回归(PLS)的统计分析方法对叶片原始光谱(R)及一阶微分光谱(FDR)进行镉质量比预测,确定最佳光谱监测方式和有效波段,提高镉胁迫估测的时效性。此外,为进一步检验上述模型的稳定性,再次布置9个独立菊苣品种镉胁迫光谱验证实验(镉浓度为50μmol/L)。结果表明,镉胁迫显著影响菊苣叶片镉质量比及高光谱反射率变化特征;随镉梯度增加,3个品种菊苣镉含量均显著提升,叶片高光谱反射率在可见光-近红外区(400～1 300 nm)逐步降低,中红外区(1 300～2 400 nm)则未表现出一致性变化规律。全波段光谱分析模型间,以基于FDR光谱的PLS监测模型(FDR-PLS)表现最优,其独立验证集决定系数(R2)、均方根误差(RMSE)和相对分析误差(RPD)分别为0. 92、181. 3 mg/kg和2. 96。根据FDR-PLS模型中各波段无量纲评价指标:变量重要性投影值(VIP),确定菊苣叶片镉质量比有效波长分别为659、725、907、1 026、1 112、1 255、1 630 nm,实现了光谱降维和便捷分析的目的。此后,再次构建基于上述有效波段的菊苣叶片镉质量比FDR-PLS监测模型,其独立验证集R2、RMSE和RPD分别为0. 834、222. 4 mg/kg和2. 41,9个供试品种验证集R2、RMSE和RPD分别为0. 817、13. 0 mg/kg和1. 77,预测效果较为理想,能够满足无损和精准监测需求。     

基于多光谱卫星模拟波段反射率的冬小麦水分状况评估

为及时掌握作物水分利用状况、评估作物水分亏缺和提高作物水分利用效率,在2012—2016年期间进行了不同水分处理的冬小麦田间试验,获取了冬小麦主要生育期冠层光谱和叶片含水量等数据。利用冬小麦冠层光谱以及Quickbird、IKONOS、GF-2、GF-1、Landsat8、HJ-1A/B、GF-4和MODIS卫星传感器光谱响应函数模拟卫星多波段反射率,参照归一化植被指数(Normalized vegetation index, NDVI)、比值植被指数(Ratio vegetation index, RVI)和差值植被指数(Difference vegetation index, DVI)的形式,将各卫星波段反射率两两组合,系统分析构建的植被指数与叶片含水量的相关性,探讨不同空间分辨率(2.44、4、8、30、50、250m)波段组合及植被指数对作物水分状况和灌溉活动的响应能力。结果表明,NDVI、RVI和DVI 3种指数对作物水分敏感区域的分布类似;8个卫星的近红外波段与叶片含水量的相关系数为正,其余几个波段与叶片含水量的相关系数为负;NDVI(GF-1绿波段,GF-2绿波段)、RVI(GF-1绿波段,GF-2绿波段)和DVI(GF-2蓝波段,GF-4蓝波段)与叶片含水量相关性较好,决定系数R2分别为0.776、0.774和0.886,以DVI形式构建的植被指数对叶片含水量的估算效果最好。本研究可为区域作物水分状况评估以及作物灌溉活动监测提供技术和方法支持。     

Overland water and salt flows in a set of rice paddies

Cultivation of paddy rice in semiarid areas of the world faces problems related to water scarcity. This paper aims at characterizing water use in a set of paddies located in the central Ebro basin of Spain using experimentation and computer simulation. A commercial field with six interconnected paddies, with a total area of 5.31 ha, was instrumented to measure discharge and water quality at the inflow and at the runoff outlet. The soil was classified as a Typic Calcixerept, and was characterized by a mild salinity (2.5 dS m⁻¹) and an infiltration rate of 5.8 mm day⁻¹. The evolution of flow depth at all paddies was recorded. Data from the 2002 rice-growing season was elaborated using a mass balance approach to estimate the infiltration rate and the evolution of discharge between paddies. Seasonal crop evapotranspiration, estimated with the surface renewal method, was 731 mm (5.1 mm day⁻¹), very similar to that of other summer cereals grown in the area, like corn. The irrigation input was 1874 mm, deep percolation was 830 mm and surface runoff was 372 mm. Irrigation efficiency was estimated as 41%. The quality of surface runoff water was slightly degraded due to evapoconcentration and to the contact with the soil. During the period 2001–2003, the electrical conductivity of surface runoff water was 54% higher than that of irrigation water. However, the runoff water was suitable for irrigation. A mechanistic mass balance model of inter-paddy water flow permitted to conclude that improvements in irrigation efficiency cannot be easily obtained in the experimental conditions. Since deep percolation losses more than double surface runoff losses, a reduction in irrigation discharge would not have much room for efficiency improvement. Simulations also showed that rice irrigation performance was not negatively affected by the fluctuating inflow hydrograph. These hydrographs are typical of turnouts located at the tail end of tertiary irrigation ditches. In fact, these are the sites where rice has been historically cultivated in the study area, since local soils are often saline-sodic and can only grow paddy rice taking advantage of the low salinity of the irrigation water. The low infiltration rate characteristic of these saline-sodic soils (an experimental value of 3.2 mm day⁻¹ was obtained) combined with a reduced irrigation discharge resulted in a simulated irrigation efficiency of 60%. Paddy rice irrigation efficiency can attain reasonable values in the local saline-sodic soils, where the infiltration rate is clearly smaller than the average daily rice evapotranspiration.     

瓦房店市水果生产标准化发展研究

瓦房店市是我国重要的水果生产基地,在国内水果生产领域占有重要地位。随着水果市场化的不断深入,如何满足和适应国内外市场需求成为瓦房店市水果生产的关键问题。从瓦房店市水果生产实际出发,阐述了实施水果生产标准化的必要性,提出了发展水果生产标准化的具体措施。     

金谷子耐旱TG118引种试种及推广应用

对引进的谷子新品种金谷子耐旱TG118进行品种比较试验和多点试种。结果表明：该品种抗旱、耐瘠、适应性强,稳产、高产、抗病抗风抗倒伏强,品质优良,粮草兼用,种植简单,省工易管;一般产量在6000kg/hm2以上,比当地主栽品种增产20%以上。最高产量达9450kg/hm2,适于在辽西北地区推广应用。     

对《种子法》存在问题的探讨

《种子法》是我国种植业第一部法律。自实施以来,为依法加强种子管理提供了有力的法律支撑,促进我国种子产业发生翻天覆地的变化。但随着依法管理工作的深入和种子产业的快速发展,《种子法》及配套规章的一些问题逐步显现出来。对《种子法》及配套规章存在的问题进行深入分析,对需要进一步补充的章节以及需要调整的内容进行深入探讨,以求更加完善和明确。     

Review of the Egyptian experience in implementing land drainage projects

About 30 years have passed since the Government of Egypt embarked on implementing a series of large scale drainage projects. At present, about 3.8 million acres have been provided with drainage systems on the basis of systematic pre-drainage investigations and designs. The target is to provide drains in approximately 6.4 million acres in the Nile Valley and Delta.The implementation of the subsurface drainage system is carried out by the public sector and private contractors under direct supervision of governmental regional departments. The implementation process depends on many factors related to the drainage material, machinery, manpower, site requirements, farmers and organizations involved. Problems and constraints are sometimes challenging, however, the annual rate of implementation has gradually increased to 170,000 acre/year.This paper discusses the different aspects involved in the implementation process of drainage systems. The development in materials, machinery and construction technologies will be reviewed. Institutional and management factors are going to be also considered.     

和谐社会理论建设的几点哲学思考

在新世纪,面对机遇和挑战,党的十六大把“社会更加和谐”作为全面建设更高水平的小康社会的一个重要目标。中国人素有社会和谐的理想;西方人自古也向往社会和谐;借鉴东西方两种和谐社会思想的经验、教训,构建社会主义和谐社会理论。     

A European irrigation map for spatially distributed agricultural modelling

We present a pan-European irrigation map based on regional European statistics, a European land use map and a global irrigation map. The map provides spatial information on the distribution of irrigated areas per crop type which allows determining irrigated areas at the level of spatial modelling units. The map is a requirement for a European scale assessment of the impacts of irrigated agriculture on water resources based on spatially distributed modelling of crop growth and water balance. The irrigation map was compiled in a two step procedure. First, irrigated areas were distributed to potentially irrigated crops at a regional level (European statistical regions NUTS3), combining Farm Structure Survey (FSS) data on irrigated area, crop-specific irrigated area for crops whenever available, and total crop area. Second, crop-specific irrigated area was distributed within each statistical region based on the crop distribution given in our land use map. A global map of irrigated areas with a 5′ resolution was used to further constrain the distribution within each NUTS3 based on the density of irrigated areas. The constrained distribution of irrigated areas as taken from statistics to a high resolution dataset enables us to estimate irrigated areas for various spatial entities, including administrative, natural and artificial units, providing a reasonable input scenario for large-scale distributed modelling applications. The dataset bridges a gap between global datasets and detailed regional data on the distribution of irrigated areas and provides information for various assessments and modelling applications.     

粉质仪和拉伸仪在面粉生产中的应用

在介绍粉质仪和拉伸仪结构和原理的基础上,探讨了粉质曲线中吸水率、形成时间、稳定时间、弱化度和评价值等指标与面粉品质的关系,以及如何根据拉伸曲线中面团最大拉伸阻力、延伸度和拉伸曲线面积等指标来评价面团品质,并结合生产实际,概述了粉质仪和拉伸仪在面粉生产中的作用。     

农村信息化服务的现状及建设措施

分析当前我国农村信息化服务的现状,提出加强农村信息化服务的新举措。     

车辆ABS控制算法的研究及探讨

对现代汽车的ABS控制算法作了一些简单的介绍,同时指出了它们的一些缺陷,相应地提出了几种对ABS的其它控制方法并加以探讨,其中着重论述了ABS门限值控制算法中参考车速的确定方法和基于附着系数的控制算法。