Crowding as an Agronomic Factor Determining the Development of Plants and the Productivity of Linseed (Linum usitatissimum L.)

ABSTRACT

Nine sowing densities of linseed were compared in a two-year experiment. Self-regulation of the density of a linseed stand resulted in a differentiated branching of the plants. The number of capsules on a linseed shoot, as well as seeds in the capsule, and the number of seeds from the shoot were highly varied from year to year, and there is even a stronger differentiation in the weight of 1000 seeds. Linear relationships were noted between the mass of seeds from the linseed plant and the number of capsules. The yield of linseed was affected by both factors. An increasing sowing rate reduced the seed yield from the shoot and the plant. At lower seeding rates, the lateral shoots contributed in the seeds yield of the plant to a higher degree compared to the main ones.     

鄂尔多斯盆地中侏罗世直罗—安定期沉积构造特征

中侏罗世直罗—安定期伴随大华北盆地分化瓦解,直罗—安定组除在鄂尔多斯盆地呈整体分布外,在其周邻地区亦有大量零星分布的同期可对比地层。在现今盆地内,直罗组主要为河流相沉积;安定组以干旱气候条件下的河流、湖泊相沉积为主。直罗—安定组的湖相沉积主要位于盆地东南部的古沉积中心部位,其堆积中心位于盆地西部的乌海—鄂托克前旗—平凉一线,堆积中心与沉积中心偏离。直罗组沉积前古构造格局为南高北低、东高西低。直罗—安定期的古地质面貌呈西北高东南低特点,南、北分异表现甚微。结合周邻同期地层岩性、岩相和现今构造单元形成时限等综合分析,认为直罗—安定期原始盆地的边界大致为:西在贺兰山之西,东达吕梁山之东、太行山以西,北抵大青山,南至秦岭。     

γ射线对叶组织电阻变化的影响及动态分析

测试了水稻和烟草两种叶片经不同剂量的^60Co γ射线辐照处理后，组织电阻及离子外渗的动态变化情况。研究结果表明：当超过一定的剂量阈值后，随着辐照剂量的增加，两种植物的叶组织电阻均呈现先上升、后下降的变化规律；叶组织电阻的改变与离子外渗的变化趋势并不一致；用测量叶组织电阻的方法可以较灵敏地体现出植物对γ射线的动态反应情况。运用电生理学的基础理论对上述生理现象的产生原因从机理上进行了分析与探讨。     

基于叶片形态特征的葡萄品种自动识别

葡萄在全世界种植范围较广,葡萄品种识别对葡萄资源统计、新品种鉴定及遗传资源保护都有重要意义。以成熟叶片为基本材料,不变矩、面积、周长、主叶脉长度和叶柄长度等11维特征向量为基础数据,采用叶片特征选择、图像处理、特征值提取、建立分类模型等方法,运用国际葡萄与葡萄酒组织形态分类方法和改进的欧式距离等技术开发一个基于葡萄叶片数字图像的葡萄品种自动识别软件。共测试17种酿酒和3种野生葡萄,识别率达87%。该方法具有自动化、识别速度快、花费低、省时省力等特点,可应用于葡萄病虫害的识别、杂交新品种双亲的判定等。     

少片渐变刚度钢板弹簧的优化设计与计算

讨论了渐变刚度钢板弹簧的载荷、变形量、刚度和应力的计算，建立了少片渐变刚度钢板弹簧的优化数学模型，利用MATLAB优化工具箱进行优化，并给出了计算实例。     

Late season nitrogen fertilization of soybeans: effects on leaf senescence, yield and environment

Nitrogen demand from soybean seeds during seed filling is very high and has been proposed as the cause of nitrogen remobilization and leaf senescence. Previous research has not shown consistent effects of late season fertilization on seed yield, while its effects on leaf senescence have not been evaluated. Two field experiments were performed to determine the effects of a late season N fertilization on leaf senescence and fall, seed yield and its components, and residual soil nitrate, and to evaluate the potential risk of groundwater contamination. Two rates of nitrogen (50 and 100 kg N ha^–1) were applied at the R3 and R5 development stages. Nitrogen fertilization, either at R3 or R5, increased soil nitrate availability during the seed-filling period. Seed yield, seed number and protein content were not affected by N fertilization. The addition of 100 kg N ha^–1 produced a small delay of 1–2 days in the leaf fall, and slightly increased seed size (3.6%). Our results suggest that increasing soil N availability during the seed-filling period is not an effective way to delay leaf senescence or to increase seed growth and yield of soybean. Nitrogen fertilization increased the level of residual nitrate in the top soil at one site (the one with lowest seed yield), increasing the risk of nitrate leaching during subsequent fallow.     

浅谈大数据时代信息服务业的发展模式转变

在移动互联网、物联网、云计算等一系列新兴技术的快速发展背景下,信息技术在经济领域、社会领域和人们的日常生活等各个方面不断的推陈出新。分别从搜索、电子商务、位置服务、网络空间和运营商等5个方面,基于案例的形式来分析新兴的信息服务业发展模式。认为未来研究可关注从社会媒体网络中获取大数据来研究市场营销问题。     

西南地区不同山地环境梯度叶面积指数遥感反演

叶面积指数(LAI)遥感估算是植被定量遥感研究的热点之一,监测植被LAI时空变化对于研究陆地生态系统碳循环及全球变化等具有非常重要的意义。在我国西南山区设置10个50km×50km的观测样区作为研究区,其中包括5个森林生态系统样区、3个农田生态系统样区和2个草地生态系统样区。分别获取不同优势植被类型LAI地面实测数据,结合同期获取的遥感数据,考虑地形因素影响,基于偏最小二乘原理分别构建各样区LAI遥感估算模型,并采用交叉验证的方式对模型精度进行评价。结果表明:考虑了海拔、坡度和坡向等地形因子的森林LAI遥感反演模型与未考虑地形变量的模型相比,其验证精度有所提高,R2由0.30~0.75提高至0.50~0.80,RMSE由0.52~0.93m2/m2降低至0.48~0.89m2/m2;所有样区优势植被类型LAI反演模型验证R2在0.40~0.80之间,RMSE在0.22~0.89m2/m2之间。发展的LAI遥感估算方法有助于认知山地植被LAI反演的地形效应问题,可为进一步的山地植被长势监测提供科学依据。     

基于图像处理的叶面积测量方法

采用数字图像处理方法对毛白杨叶片进行长、宽、面积的测算,并应用Hough变换对叶片畸变图像进行校正,取得了可靠的数据,建立了叶片长、宽、长宽乘积和面积的回归方程,结果有着显著的相关性,为植物叶面积快速估算提供了一条比较好的途径.