美洲黑杨与大青杨杂种叶片气孔导度的红外热像测量方法研究

为了研究红外热像技术在测量叶片气孔导度的应用上的可行性,以美洲黑杨与大青杨杂种(Populus deltoids Bartr.×Populus ussuriensis Kom.)为材料,在正常灌溉和干旱胁迫的对比下,利用红外热像仪考察了叶片的气孔导度Gs的日变化,根据叶片能量平衡方程分析了气孔导度与温度之间的关系,并采用便携式光合测量系统验证了红外热像测量气孔导度的准确性。结果表明：在2种水分处理条件下,叶片的气孔导度值均呈双峰曲线,峰值出现在10:00和14:00,正常灌溉和干旱条件下的峰值分别为120 mmol/(m2?s)、70 mmol/(m2?s)和80 mmol/(m2?s)、40 mmol/(m2?s);气孔导度与温度的响应呈反比趋势;气孔导度的模型计算值与实际测量值之间的关系呈线性相关,正常灌溉和干旱状态下的相关系数分别为0.8678、0.8347;气孔导度相关指数IG和水分胁迫指数CWSI分别与测量得到的气孔导度呈正比、反比的趋势。总之,与传统的利用便携式光合仪测定气孔导度相比,利用红外热像技术测量更便捷、准确,且适用性更加广泛,本研究为今后利用红外热像测量气孔导度奠定了理论基础。     

Relationship between sensory and NIR spectroscopy in consumer preference of table grape (cv Italia)

A combination of near infrared spectroscopy (NIR) instrumental measurements and sensory analysis was investigated to predict solids soluble content (SSC, assessed as Brix) and to classify preference in table grape cv Italia. SSC was monitored in each berry of whole bunches in order to evaluate intra-bunch distribution and variability. NIR spectra were recorded in the spectral region 12,000–4000 cm⁻¹ (833–2500 nm) using a set of 682 berries. The Partial Least Square (PLS) model based on cross-validation provided acceptable value for the main statistical parameters (coefficient of determination of cross-validation, r²: 0.85; standard error of cross-validation, SECV: 1.08; residual predictive deviation, RPD: 2.6) and was confirmed by external validation performed with 115 independent berries (coefficient of determination of prediction, r_p²: 0.82; standard error of prediction, SEP: 0.83). For consumer testing, the selected PLS model was used to predict the Brix value in 400 berries and Discriminant Analysis (DA) was then carried out to classify berries in terms of preference by relating NIR data to consumer judgment. The three defined preference clusters of berries were fully classified obtaining 100% membership. In cross-validation the value decreased especially for class 1 (78.5%) and 3 (75%) whereas class 2 obtained comparable values (98.7%). According to our results, NIR technology appears to be a promising technique for predicting SSC and obtaining information with regard to consumer preference in ‘Italia’ table grape for application of efficient and low cost on-line instruments in the fruit industry.     

苹果表面缺陷红外热成像检测装置及处理方法

红外热成像技术是一种可用于农产品检测的新型无损检测技术。简介了红外热成像原理及该技术用于苹果表面缺陷检测的方法。实验装置以IR790为核心,将苹果表面温场转换为热图像显示,经计算机处理与分析,最终得到苹果缺陷信息。     

地黄真空红外辐射干燥模型

利用设计的真空红外辐射干燥箱,对中药材地黄进行了真空红外干燥研究.通过对试验值进行求对数并线性回归,确定了地黄的薄层真空红外干燥模型的形式为Modified Page方程,该模型与辐射板温度和干燥室压力有关,并得到了各参数的表达式和数值.试验值和模型预测值比较说明,该模型能很好地描述和预测地黄真空红外干燥的水分比变化规律.     

光电检测技术在马铃薯品质检测中的研究进展

近年来,我国大力推动实施马铃薯主粮化战略,品质控制是重要的支撑技术,需在马铃薯的专用品种选育、主食产品加工、储藏运输及终端消费等多个产业链环节进行检测。为此,围绕马铃薯质量安全管控方面的需求,详细介绍了机器视觉技术、近红外光谱分析技术及高光谱成像技术等光电检测技术在马铃薯外观形态、内部品质及缺陷检测方面的研究和应用现状,并分析了其发展趋势,以期为马铃薯深加工过程中原料筛选和分等分级等提供参考。     

EMC单片机技术在粮仓库门控制系统中的应用

介绍了一种基于EMC单片机的粮仓库门自动控制系统.该系统分为红外遥控和接收两部分,其中红外遥控部分通过EM78P153控制红外无线遥控器发射指令信号,而红外接收部分通过接收模块接收到信号后由EM78P447来控制粮仓库门的开、关、停、限位和夜间自动点灯.系统结构简单,功能齐全,具有低成本、低功耗和可靠性高等特点.     

饲料中肉骨粉含量的近红外反射光谱检测方法

收集28份鸡饲料,31份猪饲料,25份牛饲料和肉骨粉7份,在饲料中掺入不同比例(0.5%～6.0%)的肉骨粉,制成分析样本.采用偏最小二乘(PLS)法,分别对光谱进行散射校正、平滑、一阶导数和二阶导数预处理,建立了鸡饲料、猪饲料和牛饲料中肉骨粉含量的近红外定量分析模型.利用验证集样本对定标模型进行了检验,鸡饲料、猪饲料和牛饲料中肉骨粉含量的真值与预测值之间的决定系数分别为0.9694、0.9846和0.9788;标准差分别为0.279、0.252和0.287;相对分析误差分别为5.663、6.865和5.889.结果表明,利用近红外光谱法测定饲料中的肉骨粉含量具有较高的预测精度.     

Sulphur speciation and turnover in soils: evidence from sulphur K-edge XANES spectroscopy and isotope dilution studies

Sulphur K-edge X-ray absorption near edge structure (XANES) spectroscopy was used to quantify S species in humic substance extracts from ten soils from the UK, China and New Zealand, which differ in land use and agricultural management. XANES spectroscopy showed the presence of most reduced (sulphides, disulphides, thiols and thiophenes), intermediate (sulphoxides and sulphonates) and highly oxidised S (ester sulphates) forms, with the three groups representing 14-32%, 33-50% and 22-53% of the organic S in the humic substance extracts, respectively. Land use had a profound influence on the relative proportions of S species. Well-drained arable soils generally had a higher proportion of organic S present in the most oxidised form than the grassland soils collected nearby, whereas paddy soils showed a more reduced profile due to episodic flooding. In the Broadbalk Classical Experiment at Rothamsted, reversion of an arable system to grassland or woodland in the 1880s resulted in an increase of the most reduced and intermediate S species at the expense of the most oxidised S species. Long-term applications of farmyard manure to an arable plot also shifted S species from the most oxidised to the intermediate and the most reduced species. Sulphur immobilisation and gross mineralisation were determined in seven soils using the ³⁵S isotope dilution method. Gross mineralisation during a 53-day incubation correlated more closely with the amounts of the most reduced and intermediate S species than with the most oxidised S species, suggesting that the former (C-bonded S) were the main source of organic S for mineralisation in the short-term.     

傅立叶变换近红外光谱法检测白酒总酸和总酯

该文研究白酒总酸和总酯的快速检测技术,通过解析不同白酒样品的近红外光谱图,对光谱数据进行不同的处理,结果表明：用一阶导数预处理光谱,谱区选择6102～5446 cm^-1,利用人工神经网络与傅立叶变换近红外光谱相结合,采用内部交叉验证法建立模型,效果较好。其中,总酸模型的决定系数为96.73%,内部交叉验证均方根差为0.048 g/L;总酯模型的决定系数为99.58%,内部交叉验证均方根差为0.085 g/L;进一步对总酸和总酯的模型进行验证和评价,结果表明总酸模型验证集的相关系数为99.2%,预测标准偏差为0.074 g/L;总酯模型验证集的相关为99.7%,预测标准偏差为0.134 g/L,表明建立的模型可靠,预测效果好,能满足白酒生产中总酸和总酯的快速检测要求。     

Thermal Infrared Radiation for Assessing Crop Water Stress in Wheat

Field studies on differentially irrigated wheat ( Triticum aestivum L.) crops were conducted at Pantnagar for two years to evaluate the use of thermal infrared radiation to detect crop water stress. Data show that the stress-degree-day index (mid day canopy-air temperature difference) is influenced by environmental variability other than soil moisture. Improvement in the stress-degree-day (SDD) index was achieved by including the measurements of vapor pressure deficit and approach was termed as plant water stress index (PWSI). Observations indicated that daily variation in SDD values due to meteorological changes was removed through PWSI. Better correlation was found between soil-induced leaf water potential and plant water stress index than between total leaf water potential and plant water stress index. It is concluded that remote sensing of thermal infrared radiation offers a promising technique which can be incorporated into irrigation management programme.