橙皮苷的提取工艺研究

[目的]研究以95％甲醇和碱液做溶剂从橘皮中提取橙皮苷的工艺条件。[方法]通过对溶剂、甲醇浓度、温度、pH值、浸提次数进行试验确定提取橙皮苷的最佳工艺条件。[结果]以桔皮为原料,用碱液和甲醇做溶剂提取橙皮苷的最佳工艺条件为：粗苷：甲醇：碱液[W（NaOH）为30％]=11：30：8,在85℃以上浸泡4h,调节pH值为4。即先将甲醇和碱液搅拌混合,再将粗苷加入,继续搅拌1h使粗苷溶解完全,然后过滤至滤液澄清,用盐酸调滤液的pH值至4,静置沉淀,过滤,滤饼用煮沸过的水洗涤至无色,甲醇滤液精馏回收,橙皮苷的收率迭65％以上。[结论]此方法操作简便,易控制且提取橙皮苷的效率较高。     

常温可逆温致变色农用塑料薄膜光谱透射率及其对温度的影响

采用模拟田间试验和仪器测量方法,研究了常温可逆温致变色农用塑料薄膜光谱透射率及其对温度的影响。结果表明,与对照（透明塑料薄膜）相比,变色塑料薄膜在400-900mm部分透过率在30％～50％,遮阳效果显著;变色塑料薄膜具有极好的阻隔紫外线能力,在190-340mm部分透过率在0～10％,最大下降幅度高达100％;变色塑料薄膜在变色状态和非变色状态时的光谱透射率在可见光和红外线部分（380～900nm）变化率在40％～60％,红／白变色塑料薄膜的光谱透过率下降幅度较黑／白变色塑料薄膜要大;变色地膜覆盖在高温时可使地温比普通透明地膜低3—4℃,低温时迅速升温,较普通地膜高出2～3℃,降温时,地温较普通透明地膜高1～2℃;变色棚膜覆盖,中午强日照时温度比普通棚低3～4℃,而太阳初升时迅速升温,温度较普通棚高出2～4℃;红／白变色塑料大棚内／外的光合作用光子通量PPF、光照度FC与LUX实测值的差异很小,说明温致变色塑料薄膜对400～700mm的可见光透过率影响不大。     

昆山麻鸭重要遗传种质特性的检测与分析

为了揭示昆山麻鸭的遗传特性,在昆山麻鸭保种场对昆山麻鸭重要遗传种质特性进行了检测,这些性状包括繁殖性能、体尺性状以及肉用性能。同时分别对体尺性状、肉用性状各指标间的表型相关进行了分析。结果表明：体尺性状的变异系数均小于10%,而肉用性能指标的变异系数均超过了10%,说明肉用性能的变异程度大于体尺性状,肉用性能的遗传稳定性差。母鸭的半净膛率和全净膛率差异极显著高于公鸭（P＜0.01）,说明母鸭的出肉率高于公鸭。相关分析结果表明,宰前活重、屠体重、半净膛重、全净膛重、胸肌重间均存在极显著的正相关（P＜0.01）,且相关系数均在0.828以上,全净膛重和半净膛重的相关系数达0997,决定系数（r2）达0.994,全净膛率和半净膛率相关系数达0.990,决定系数达0.98,说明这些性状间的关系密切,选择宰前活重可以间接选择屠体重和全净膛重。     

冬小麦冠层高光谱特征与覆盖度相关性研究

在2010年度与2011年度冬小麦生长季大田试验小区,实测了3个播种密度、3个灌水水平下冬小麦冠层的高光谱反射率与覆盖度。分析了冬小麦冠层光谱特征以及不同生育期冬小麦冠层光谱特征参数与覆盖度的相关性,建立了基于光谱特征参数的不同生育期冬小麦覆盖度估算模型。结果表明:从返青到成熟,冬小麦冠层可见光区光谱反射率先减小后增大,近红外区先增大后减小。不同种植密度下,适宜供水冬小麦在可见光波段的反射率依次小于轻度亏水、重度亏水条件下的冬小麦;在近红外波段,规律正好相反。在相关性分析中,传统光谱特征参数和新光谱特征参数与覆盖度在不同生育期均具有较好的相关性。相比以传统光谱特征参数为自变量的冬小麦覆盖度估算模型,基于绿峰峰度的估算模型可以提高冬小麦覆盖度的估算精度。     

干旱胁迫下油菜含水率的高光谱遥感估算研究

[目的]研究基于光谱分析技术进行油菜含水率定量分析的有效方法。[方法]采用区间分段逐步回归法提取特征波长,在此基础上,建立了油菜含水率的定量分析模型,对不同干旱胁迫下油菜样本的光谱数据进行分析。[结果]960、1 450、1 650 nm波段的光谱反射率与油菜含水率呈极显著相关。油菜含水率模型预测值与实测值的相关系数为0.87,模型的均方根误差（RMSE）为4.57。[结论]该方法能够准确地提取光谱特征,提高模型的预测精度。     

RTDrift: A real time model for estimating spray drift from ground applications

A spray drift model called RTDrift was developed to estimate drift caused by ground sprayer machines. The sprayer was equipped with sensors measuring operational parameters namely spray pressure, boom height and movements, and geolocalisation. Climatic parameters, including wind speed and direction, were measured using a 2-D ultrasonic anemometer mounted on the sprayer. The nozzles spray drop size spectra were characterised using Phase Doppler Interferometer measurements. At every successive boom position, a diffusion-advection Gaussian tilted plume model computed the spray drift deposits for each drop class taking into account evaporation. The contribution of a single nozzle was calculated by integration of the individual puffs with respect to time and summation of the contributions of individual drops classes. The overall drift generated by the sprayer machine was obtained adding the contributions of all the nozzles. Field trials were performed on a fallow field with water and on crops with pesticides in various wind conditions. The ground drift was measured at different drift distances using fluorometric methods. When comparing the results of the model with experimental measurements of deposits, the model produced realistic maps of drift deposits. Some further improvement is needed in the presence of large scale eddies. The model offers potential benefits for the farmer as a real time drift estimator embedded on a sprayer machine.     

油菜氮素的高光谱特征补偿和组合模型研究

[目的]探索油菜氮素光谱分析中水氮交互的解耦方法。[方法]提出了利用反射率特征补偿和组合模型分析法对水分因素对氮素检测的影响进行补偿的方法,并分别建立了氮素光谱分析模型。[结果]利用特征补偿法和模型分类组合分析法进行修正的氮素诊断模型的预测值与实测值的相关系数R分别为0.89和0.91,均方根误差（RMSE）分别为2.94和1.47。[结论]利用模型分类组合分析法能够有效地对水氮交互进行解耦,油菜氮素的定量分析效果较好。     

山西创意农业发展思路与对策

创意农业是一项综合性的系统工程,也是对传统农业发展模式的一种创新。在分析主要发达国家创意农业模式、我国创意农业发展现状和山西省创意农业发展状况的基础上,提出了山西省创意农业发展对策建议。     

海南民营橡胶产业现状及发展对策

简要介绍了海南省民营天然橡胶种植历史,从种植、加工、销售和对农民的增收作用等4个方面概述了海南民营天然橡胶发展现状,剖析了海南民营天然橡胶产业中的优势和存在的主要问题,提出了海南民营天然橡胶发展对策。     

Partial least squares regression (PLSR) associated with spectral response to predict soil attributes in transitional lithologies

New techniques and improvements are required to quantify soil’s chemical and physical properties on production environment, reducing environmental impacts and minimizing soil analysis time. The aim of this study is to evaluate the possibility to estimate the content of silt, sand, clay, total iron and organic matter in soils formed by different lithologies in Parana State, Brazil, using VIS-NIR spectrum associated with Partial Least Square Regression (PLSR). 200 soil samples were collected in an area formed by Lixisols, Cambisols, Ferralsols, Arenosols and Nitisols in a depths of 0–0.2 and 0.2–0.8 m. Spectral readings were obtained in laboratory by FieldSpec 3 JR sensor. The spectral curves of the samples were correlated to the attributes through PLSR. The results obtained for sand in prediction were better when compared to the other attributes, presenting R² = 0.90, r = 0.95 and RPD = 2.3. Clay and total iron presented satisfactory results, mainly for RPD values, which were above 2.4. Based on the results, it can be concluded that the PLSR technique associated with the spectral response of the soils, was able to estimate sand, clay and total iron with accuracy in a region formed by reworked materials, derived from several lithologies.