利用Radon函数变换对木材纹理方向自动检测的研究(英文)

本文提出一种利用计算机自动检测木材纹理方向的新方法。四种Matlab 图像变换函数被尝试用于木材纹理形状的检测。通过比较发现BWMORPH 是最适于检测木材这类中弱纹理的函数,并提取生成了木材纹理骨骼线图像;再对木材纹理骨骼线图像进行Radon变换,得到0°~180°范围内每一角度上的纹理线在投影变换域的积分值,并绘制出纹理线积分值随角度变化的二维曲线图以反映木材纹理角度上的变化规律。进而分析了国内40 个树种的纹理方向曲线图以及它们以针叶、阔叶树材和径向、弦向切面作区别的分类统计规律。结果显示,根据Radon 变换图及其纹理曲线图所反映的木材纹理的方向性规律与人们平常对木材纹理的印象相吻合。这也证明了此种新方法的有效性以及它的应用潜力。图7参6。     

基于双树复小波变换和邻域操作的哈密瓜纹理提取

为研究哈密瓜表面纹理特征分布规律,采集金密16号9成熟、全熟和金密17号9成熟、全熟共168幅哈密瓜样本图像,对RGB彩色图像的R、G、B分量执行代数运算,转换为灰度图后进行背景分割,然后利用双树复小波变换(DT-CWT)分解图像,获取高频子图像,并对其执行邻域操作,采用迭代法选取最优阈值完成纹理提取,最后利用灰度差分统计法和纹理频谱分析法描述分析哈密瓜纹理特征,建立基于支持向量机(SVM)的分类模型。研究结果表明,利用DT-CWT和邻域操作相结合的方法可得到更加连续、完整的哈密瓜纹理图像;4种哈密瓜的纹理特征值差异显著,利用纹理特征值分类准确率为89.3%;哈密瓜表面纹理无周期性。     

基于纹理差异度引导的DRLSE病虫害图像精准分割方法

为精准分割纹理背景下的病虫害目标,提出一种基于混合高斯模型的纹理差异度表示方法和基于纹理差异度引导的DRLSE农作物病虫害精准分割方法。采用基于混合高斯模型的纹理差异度表示方法得到纹理差异度图像,利用Otsu自动阈值分割和形态学后处理得到农作物病虫害DRLSE演化的初始区域,将基于改进纹理差异度的边缘停止函数应用到DRLSE演化中。实验结果表明该方法可以获得精准的害虫和病变区域轮廓。     

W/O及W/O/W乳液型缓释凝固剂对卤水豆腐品质的影响

以W/O、W/O/W乳状液形式包埋盐卤,制备成具有缓释作用的新型乳液型豆腐凝固剂,应用于豆腐生产。研究发现：乳化型凝固剂可以减缓凝固剂与大豆蛋白的作用强度,改善豆腐凝胶的空间结构,降低凝胶硬度,而保持原有弹性。乳液凝固剂的使用能一定程度上减少豆腐加工过程中蛋白质和大豆异黄酮的物理损失,提高大豆异黄酮保有量。此外,豆腐凝胶亮度与白度均有上升。     

应用激光粒度仪分析土壤机械组成的实验研究

土壤机械组成是最基本的土壤参数之一。探讨了应用激光粒度仪分析土壤机械组成的实验条件、检测结果与精度,并与传统的吸管法加以比较。对9个土壤样品分别用激光粒度分析和吸管法作对比测试实验,结果显示:两种方法原理的不同产生了在颗粒含量上激光粒度分析得到的粘粒含量显著低于吸管法,但是两种方法在质地分类上的结果是基本一致的。总之,运用激光粒度分析土壤机械组成是可行的。     

东北黑土有机碳、全氮空间分布特征

应用经典统计学方法,分析了东北黑土表层1100个样点的土壤有机碳(SOC)和全氮空间分布规律。结果表明土壤有机碳和全氮平均含量分别为19.25 g kg-1和1.89 g kg-1,从南到北随纬度增加而增加,土壤有机碳和全氮与纬度的相关系数分别为0.70和0.76;土壤有机碳、全氮与黏粒、砂粒在P<0.01水平上显著相关,其中与砂粒为显著负相关,而SOC与粉粒则在P<0.05水平下显著正相关;土壤全氮与粉粒没有相关性。     

A method for predicting soil susceptibility to the compaction of surface layers as a function of water content and bulk density

Identifying the vulnerability of soils to compaction damage is becoming an increasingly important issue when planning and performing farming operations. Soil compaction models are efficient tools for predicting soil compaction due to agricultural field traffic. Most of these models require knowledge of the stress/strain relationship and of mechanical parameters and their variations as a function of different physical properties. Since soil compaction depends on the soil's water content, bulk density and texture, good understanding of the relations between them is essential to define suitable farming strategies according to climatic changes. In this work we propose a new pedotransfer function for 10 representative French soils collected from cultivated fields, a vineyard and forests. We investigate the relationship between soil mechanical properties, easily measurable soil properties, water content and bulk density. Confined compression tests were performed on remoulded soils of a large range of textures at different initial bulk densities and water contents. The use of remolded samples allowed us to examine a wide range of initial conditions with low measurement variability. Good linear regression was obtained between soil precompression stress, the compression index, initial water content, initial bulk density and soil texture. The higher the clay content, the higher the soil's capacity to bear greater stresses at higher initial water contents without severe compaction. Initial water content plays an important role in clayey and loamy soils. In contrast, for sandy soils, mechanical parameters were less dependent on initial water content but more related to initial bulk density. These pedotransfer functions are expected to hold for the soils of tilled surface layers, but further measurements on intact samples are needed to test their validity.     

放养与笼养对宣城麻黄鸡肌肉品质的影响

试验对20只宣城麻黄鸡在放养和笼养条件下腿部肌肉品质进行了测定,结果表明：（1）笼养组腿肌亮度（L）、黄度（b）分别较放养组高4.23%和32.05%,差异显著（P〈0.05）;蒸煮损失、硬度、黏性和咀嚼性分别较比放养组高20.96%、44.38%、35.72%和33.50%,差异极显著（P〈0.01）;而pH24、红度（a）、弹性、粘聚性和肌纤维直径,两组差异不显著（P〉0.05）。（2）笼养状态下,腿肌肌纤维直径与弹性、咀嚼性相关性均为显著正相关（P〈0.05）,与L为显著负相关（P〈0.05）;其它肉质指标间均为不显著相关（P〉0.05）;放养状态下,腿肌肌纤维直径与弹性、咀嚼性、L相关性均为不显著正相关（P〉0.05）,而与蒸煮损失相关性为极显著正相关（P〈0.01）,与pH24极显著负相关（P〈0.01）;L与蒸煮损失为极显著正相关（P〈0.01）,b与弹性为显著正相关（P〈0.05）。其它肉质指标间也均为不显著相关（P〉0.05）。     

Soil microbial community response to surfactants and herbicides in two soils

The environmental impacts of herbicides on desirable plants and the soil biota are of public concern. The surfactants that are often used with herbicides are also under scrutiny as potentially harmful to soil biological systems. To address these concerns, we used two soils, a silt loam and a silty, clay loam from south central Missouri, to investigate the impacts of herbicides and surfactants on soil microbial communities using phospholipid fatty acid (PLFA) analysis. The surfactants used in this study were alkylphenol ethoxylate plus alcohol ethoxylate (Activator 90), polyethoxylate (Agri-Dex), and a blend of ammonium sulfate, drift reduction/deposition polymers and anti-foam agent (Thrust). The herbicides were glyphosate, atrazine and bentazon. Surfactants and herbicides were applied to soils at label rate, either alone or combined, to 4000 g soil per pot. The two soils differed in history, texture, some chemical characteristics and several microbial community characteristics. A few of the chemicals altered some of the components of the microbial community after only one application of the chemical at field-rate. The Cole County, MO silt loam showed larger changes in the microbial community with application of treatments. For the Boone County, MO silty clay loam, Activator 90, Agri-Dex and bentazon treatments increased microbial biomass determined by PLFA; Thrust decreased PLFA markers, bacteria to fungi ratio; and Agri-Dex at both rates decreased monounsaturated fatty acids. Changes in the microbial community due to herbicides or surfactants were minimal in this study of a single application of these chemicals, but could be indicators of potential long-term effects. Long-term studies are needed to determine the changes in the microbial community after several years of annual applications of herbicides and surfactants on a wide array of soil types and management practices.     

基因型和环境对面团流变学特性的影响研究

用揉混仪和质构仪研究了3个不同品质类型的冬小麦品种在8个不同的生长环境条件下的面团流变学特性,分析了基因型和环境对性状的影响及各性状间的相关性。结果表明：面团流变学特性受基因型（G）和环境（E）及其互作的共同作用,其中基因型方差均值＞环境方差均值＞G×E互作均值;从性状的表现看,基因型以济麦20表现最佳,环境以烟台点综合表现最好;相关分析表明,面团粘度性状与最大拉伸阻力、拉伸比、峰值时间、峰值面积和8min带宽呈显著负相关,而与延伸度呈显著正相关。最大拉伸阻力与峰值时间、峰值面积和8min带宽呈显著正相关。因此,进行品质评价时,可用质构仪测定的面团粘度特性对面团品质进行初步快速的评定。