采用区域生长法分割根系CT图像的改进算法

提出了一种基于阈值分析和区域生长相结合的用于植物根系CT序列图像分割的算法。首先通过直方图分析,初步确定根系区域的分割阈值,再利用经过改进的区域生长法分割得到目标区域。实验结果表明,该分割算法计算量小,分割精度高,在提取目标的同时,能够有效地分离介质(背景)像素;而且对于背景复杂、噪声较大、目标像素灰度不均匀的CT图像也能取得较好的分割效果。     

水稻旱作覆膜节水增产试验研究

通过水稻旱作全程覆膜与半程覆膜、旱作不覆膜及水栽对比试验，研究其耗水规律，计算其节水量与增产量，并进行经济效益分析，提出了适合本地区的栽培模式。     

水稻灌溉效益分摊系数试验研究

通过试验方法，选择不同的降雨年型，系统地分析了淠史杭灌区不同降雨年型的灌溉增产率，灌溉效益扮摊系数；找出了水稻灌溉效益分摊系数与水稻生育期降雨量，灌水量之间的经验公式，对本地区及气候条件相似地区具有一定的参考价值。     

双低菜籽粕对草鱼和鲤甲状腺、肝、肾组织结构的影响

以组织学方法,研究了投喂不同含量双低菜籽粕对草鱼和鲤甲状腺、肝、肾组织的影响。结果表明:在试验的前28 d,双低菜籽粕各不同含量的日粮(17%、34%、51%、68%)对草鱼甲状腺、肝脏组织没有影响,但菜籽粕含量为68%的试验组草鱼肾小管上皮出现颗粒变性。第42天后,菜籽粕含量为68%的试验组草鱼甲状腺滤泡上皮轻度增生,滤泡结构不规则;菜籽粕含量等于或大于51%的试验组草鱼肝脏出现颗粒变性和空泡变性,肾小球有透明变性,肾脏轻度淤血。在试验的第28天,双低菜籽粕含量等于或大于52.2%的试验组鲤甲状腺滤泡上皮细胞的高度增加,肝细胞空泡变性,有轻微的肾小球透明变性。第42天后菜籽粕含量等于或大于34.8%的试验组鲤甲状腺滤泡上皮细胞的高度增加,滤泡胶质的边缘出现缺刻;肝脏出现淤血,部分肝细胞坏死;肾小球透明变性,肾脏淤血。     

Effect of Soaking on Nitrate Concentrations in Teff Hay

Soaking can affect respirable dust particles and the concentrations of some nutrients in alfalfa and cool season grass hays. However, the effect of soaking on nitrates in hay has not been reported. The aim of this study was to evaluate the effects of soaking on teff hay, a warm season annual grass, that contained high concentrations of nitrate (>2.0%). Six bales of teff hay were used for the study. Six 0.5 kg samples were taken from each bale and assigned to one of six soaking treatments: no soaking (control), cold water immersion for 10 seconds, warm water immersion for 10 seconds, cold water soaking for 1 hour, warm water soaking for 1 hour, and cold water soaking for 8 hours. After soaking, hay was dried, ground, and submitted to a commercial laboratory for analysis. Data were analyzed by analysis of variance as a block design. When the main effect of treatment was significant (P < .05), means were separated by Tukey's honest significant difference test. Soaking for 1 or 8 hours decreased water-soluble carbohydrate (P < .0001). Phosphorus, potassium, sodium, and zinc concentrations were reduced by soaking for 1 hour or longer (P, K, Na: P < .0001; Zn: P = .003). Nitrate concentrations were reduced (P < 0.05) to safe levels for horses (≤0.5%) by soaking hay for 1 hour or longer but soaking also reduced the concentrations of some nutrients in the hay. Minimal differences were observed between cold and warm soaking temperatures.     

青海省海北州草地畜牧业情况调研

青海省海北州是草资源较为丰富的地区,畜牧业经济在全州国民经济中占主导地位。通过调研,基本摸清了海北州草资源使用情况和存在的问题,并提出了相应的意见及建议,以期为海北州畜牧业发展再上新台阶奠定基础。     

The use of a new portable erosion measuring device for assessing the erodibility of the surface layers of flood embankments

When a river overtops its flood banks, water running down the landward side of the bank can rapidly erode the soil surface and scour the bank, sometimes leading to breaches and collapse. A covering of living vegetation, particularly grass, can reduce this risk of water erosion. As part of a project to assess the effectiveness of different management regimes on bank vegetation cover, direct measurements were required of the erodibility of the soil surface. A portable erosion measurement device (EMD) was developed by LAB Coastal with the support of the Environment Agency. This could direct water flowing at known velocities across areas of the flood banks, and it was used to test directly the erosion resistance of vegetated grass banks at three sites. The EMD gave a direct measure of the erodibility of a small sample of flood bank. While measurements of soil strength and assessments of vegetation cover were useful, they did not always correctly characterize the stability of the bank surface as measured directly by the EMD. The EMD and its use are described and the results obtained are discussed. The results indicate that flood banks need to be mown at least once a year to make them less vulnerable to erosion.     

酵母细胞壁多糖与铝硅酸盐复合物对猪生长性能、免疫指标及养分消化率的影响

本研究旨在探讨酵母细胞壁多糖(yeast polysaccharide,YP)与铝硅酸盐复合物(alumi-nosilicate complex,AC)对猪的生长性能、免疫指标及养分消化率的影响。试验选用平均体重为(66.18±1.26)kg的"杜×长×大"三元杂交猪140头,随机分成5组,每组4个重复,每个重复7头猪。各组分别饲喂添加不同剂量复合物的试验饲粮,A组为对照组,不添加复合物;B组添加0.1%YP;C组添加0.1%YP和0.9%AC;D组添加0.1%YP和1.9%AC;E组添加0.1%YP和2.9%AC。试验期51 d。结果表明:1)D、E组平均日增重显著低于对照组(P<0.05),各组平均日采食量和料重比差异不显著(P>0.05);2)与对照组相比,D组血清谷胱甘肽过氧化物酶(GSH-Px)活性及补体3(C3)、免疫球蛋白M(IgM)、免疫球蛋白A(IgA)、免疫球蛋白G(IgG)水平显著提高(P<0.05),血清超氧化物歧化酶(SOD)活性和补体4(C4)水平无显著差异(P>0.05);3)各组养分消化率无显著差异(P>0.05)。由此可见,YP和AC复合使用降低了育肥猪的生长性能,0.1%YP和1.9%AC同时添加可增强生长猪的免疫功能。     

DF-2型水草卷绕机的研制与使用

介绍了ＤＦ－2型水草卷绕机的设计重点，及其主要结构、工作原理、保养要求和使用效果。     

腾冲过路黄的生长动态观察研究

对腾冲过路黄的物候期进行观察，并绘制出物候图谱。测定其各器官生长动态，结果显示：腾冲过路黄的根系集中分布层深度为10～26 cm，其茎含水量平均为82.02％，叶含水量平均为79.87％，根含水量平均为85.68％。采用相关分析及建立生物量一元线性回归方程，茎、叶、根的生物量（干重Y）可分别用Y=0.0213X4.3369、Y=0.0565X3.9657、Y=0.0382X3.517来推测。