粉末进样ICP—AES法测定大米,小麦,茶叶中的微量元素

由于ICP采用加电弧装置,使等离子体性能有所改善,提高了样品的蒸发效率,一定程度上抑制了基体效应和粒度效应,对样品中Cu、Zn、Fe、Mg、Pb、Co、Ba等元素的测定,取得较好的效果。     

用Priestley—Taylor公式估算冬小麦农田实际蒸散

本文以田间试验资料为基础，综合考虑了气象，作物和土壤因素对农田实际蒸散的影响，采用Ｐｒｉｅｓｔｌｅｙ－Ｔａｙｌｏｒ公式，并且结合叶面积指数和相对有效土壤湿度建立了冬小麦农田实际蒸散计算模型，该模型仅需常规气象资料和农业气象资料，计算简便，具有一定的应用价值。     

吲熟酯对水稻及小麦幼苗生理特性的影响

报道了在给定的浓度范围内，吲熟酯（Ｅｔｈｙｃｈｌｏｚａｔｅ）和吲哚乙酸（ＩＡＡ）对水稻及小麦幼苗根长、根数、芽长的影响，为进一步了解吲熟酯对植物的生理特性的影响，提供了基础性数据     

用马尔柯夫分析法预测麦蜘蛛发生趋势

本文研究了马尔柯夫分析法在预测麦蜘蛛发生趋势中的应用。结果表明 ,此法的预测效果令人满意。此法可对麦蜘蛛的发生趋势进行超长期预测     

Gamma irradiation influence on wheat flour gelatinisation

Differences were detected by DSC between gelatinisation and amylose-lipid complex transition occurring in suspensions of control and irradiated with 30 kGy wheat flour characterised by a dry matter to water ratio equal to ca. 1:1 and the dependence of the results on the heating rate. Two steps viscosity was discovered using of Brabender viscograph for the wheat flour irradiated with 1-30 kGy dose (apart to an essential decrease in maximum viscosity) while a one step process occurs in the case of the control one. It was compared to one step viscosity jump observed in the case of rye flour, both control and irradiated. The results are discussed in terms of radiation induced changes in starch granules. Storage of the suspensions at -20°C led to an additional exothermic effect, preceding well-recognised gelatinisation effect. This revised version was published online in August 2006 with corrections to the Cover Date.     

离子束注入对小麦幼苗保护酶活性及脂质过氧化作用的影响

采用能量为2 5 ke V的N+不同剂量(2×1 0 1 6 N+ / cm2、4×1 0 1 6 N+ / cm2、6×1 0 1 6 N+ / cm2、8×1 0 1 6N+ / cm2、1 2×1 0 1 6 N+ / cm2 )注入新疆春小麦种子,研究了N+离子束注入小麦种子后对小麦幼苗体内超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和丙二醛(MDA)含量的影响.结果表明,离子束注入新疆春小麦种子后,该种子萌发的幼苗体内MDA积累减少,SOD活性降低;高剂量注入后,CAT和POD活性提高.     

基于红边位置提取验证成像与非成像高光谱数据的一致性

定量遥感是当前遥感发展的前沿,作物组分信息解析是农业定量遥感的研究热点,而成像高光谱技术为解决微观尺度的作物组分信息探测研究提供了强有力的手段.利用成像光谱仪( pushbroom imaging spectrometer,PIS)与地物光谱仪(FieldSpec ProFR2500,ASD)同步收集冬小麦、玉米不同生...     

Measurement of water absorption capacity in wheat flour by a headspace gas chromatographic technique

The purpose of this work is to introduce a new method for quantitatively analyzing water absorption capacity in wheat flour by a headspace gas chromatographic technique. This headspace gas chromatographic technique was based on measuring the water vapor released from a series of wheat flour samples with different contents of water addition. According to the different trends between the vapor and wheat flour phase before and after the water absorption capacity in wheat flour, a turning point (corresponding to water absorption capacity in wheat flour) can be obtained by fitting the data of the water gas chromatography peak area from different wheat flour samples. The data showed that the phase equilibrium in the vial can be achieved in 25 min at desired temperature (35°C). The relative standard deviation of the reaction headspace gas chromatographic technique in water absorption capacity determination was within 3.48%, the relative differences has been determined by comparing the water absorption capacity obtained from this new analytical technique with the data from the reference technique (i.e., the filtration method), which are less than 8.92%. The new headspace gas chromatographic method is automated, accurate and be a reliable tool for quantifying water absorption capacity in wheat flour in both laboratory research and mill applications.     

Rapid characterization of molecular chemistry,nutrient make‐up and microlocation of internal seed tissue

Wheat differs from corn in biodegradation kinetics and fermentation characteristics. Wheat exhibits a relatively high rate (23% h^?1) and extent (78% DM) of biodegradation, which can lead to metabolic problems such as acidosis and bloat in ruminants. The objective of this study was to rapidly characterize the molecular chemistry of the internal structure of wheat (cv. AC Barrie) and reveal both its structural chemical make‐up and nutrient component matrix by analyzing the intensity and spatial distribution of molecular functional groups within the intact seed using advanced synchrotron‐powered Fourier transform infrared (FTIR) microspectroscopy. The experiment was performed at the U2B station of the National Synchrotron Light Source at Brookhaven National Laboratory, New York, USA. The wheat tissue was imaged systematically from the pericarp, seed coat, aleurone layer and endosperm under the peaks at ～1732 (carbonyl C=O ester), 1515 (aromatic compound of lignin), 1650 (amide I), 1025 (non‐structural CHO), 1550 (amide II), 1246 (cellulosic material), 1160, 1150, 1080, 930, 860 (all CHO), 3350 (OH and NH stretching), 2928 (CH₂ stretching band) and 2885 cm^?1 (CH₃ stretching band). Hierarchical cluster analysis and principal component analysis were applied to analyze the molecular FTIR spectra obtained from the different inherent structures within the intact wheat tissues. The results showed that, with synchrotron‐powered FTIR microspectroscopy, images of the molecular chemistry of wheat could be generated at an ultra‐spatial resolution. The features of aromatic lignin, structural and non‐structural carbohydrates, as well as nutrient make‐up and interactions in the seeds, could be revealed. Both principal component analysis and hierarchical cluster analysis methods are conclusive in showing that they can discriminate and classify the different inherent structures within the seed tissue. The wheat exhibited distinguishable differences in the structural and nutrient make‐up among the pericarp, seed coat, aleurone layer and endosperm. Such information on the molecular chemistry can be used for grain‐breeding programs for selecting a superior variety of wheat targeted for food and feed purposes and for predicting wheat quality and nutritive value in humans and animals. Thus advanced synchrotron‐powered FTIR technology can provide a greater understanding of the plant–animal interface.     

Calorimetric and rheological properties of wheat flour suspensions and doughs: Effects of wheat types and milling procedure

Three types of wheat were submitted to two different milling procedures, giving rise to six flours which differed by some physico-chemical characteristics such as particle size, level of damaged starch and protein content. Differential scanning calorimetry was used for monitoring heat-induced structural changes in flour aqueous dispersions 80% water and in doughs 45% water. Differences between the thermal behaviour of the flour dispersions and doughs were explained mainly by differences in protein content. This result was confirmed after partial substitution of flour by gluten. Dynamic mechanical analysis performed at 20°C on the flour doughs indicated, as expected, a linear increase in the elastic modulus with increasing protein content. The results did not bring any evidence that, under these experimental conditions, starch damage might affect gluten hydration.This revised version was published online in November 2005 with corrections to the Cover Date.