抽穗至成熟期气温对弱春性小麦千粒重和不孕小穗率的影响

弱春性小麦品种的千粒重和不孕小穗率呈极显著的负相关.抽穗至成熟期间的适温范围是21～26℃.千粒重与抽穗至成熟天数呈极显著的正相关.在抽穗至成熟期间,千粒重与平均日均温呈负相关,与平均日最高温度呈极显著的负相关,而与平均昼夜温差呈极显著的正相关.     

三种拂子茅种群圆锥花序小穗分布规律的比较

对拂子茅、假苇拂子茅、硬拂子茅３种拂子茅种群圆锥花序小穗的分布格局分析，结果表明，３种拂子茅种群在各节位上的小穗数均适合于Ｗｅｉｂｕｌｌ分布，随着节位序的增加均呈饱和型指数增长，通过赋予各统计参数生物生态学涵义，从宏观上分析与揭示了有关生命现象与发展规律及其生物生态学机理。     

长期定位施用氮肥对蔬菜产量的影响（一）

在蔬菜氮肥长期定位试验条件下分析了不同类型蔬菜生物产量、经济产量及经济（产量）系数的变化以及与土壤肥力的关系，建立了处理条件下的产量变化模型，进一步证明了有机肥与Ｎ素化肥配施的显著增产效果，根据蔬菜的产量效应将试验蔬菜划分为喜Ｎ型蔬菜、忌高Ｎ型蔬菜及Ｎ素敏感性蔬菜３种类型，并提出Ｎ肥施用上应注意的问题     

An Improved Non-destructive Method for Rapid Estimation of Leaf Area in Sunflower Genotypes

Measurement of total leaf area per plant in crop improvement programmes for a variety of purposes is often very tedious and time consuming. In this paper, we offer a rapid and non-destructive method of estimating the total leaf area in sunflower at the time of anthesis. We show that multiplying the leaf area of a specific leaf position from the apex by the total number of leaves per plant yields total leaf area with more than 95 % accuracy. The specific leaf position for any given genotype in sunflower can be arrived at by multiplying the total number of leaves per plant by the factor 0.355 and rounding off to the nearest highest integer. This technique can be used for the rapid estimation of leaf area per plant at anthesis for any given genotype of sunflower.     

用拓扑变换对空间连杆机构按极限位置和行程速比的综合

空间两轴垂直交叉的RSSR曲柄摇杆机构和RSSP曲柄滑块机构,是空间连杆机构中应用最广泛的四连杆机构。本文运用拓扑变换原理,对RSSR和RSSP这两种机构,按极限位置和行程速比的综合进行了分析研究。导出了其尺寸参数的计算公式,并提出了电子计算机辅助设计和绘图的程序框图,以定量的方法分析设计机构的可动性,这一方法具有图文并茂,形数结合,结论准确,容易理解等特点,编成软件后,使用极其方便。因而,是一种较为理想的方法。可供有条件的单位应用。     

Importance of water loss in the chilling injury of grapefruit stored at low temperature

Differences in chilling injury susceptibility of grapefruit from exterior and interior tree canopy positions were used to investigate the hypothesis that water loss is related to chilling injury symptom development during low-temperature storage. The sun-exposed surface of grapefruit from exterior canopy positions was more susceptible to chilling injury and had lower diffusive resistance than the shaded surface of the same fruit. Reducing the rate of fruit transpiration during the first week of storage by a pre-cooling treatment prior to low-temperature storage delayed, but did not eliminate, the development of chilling injury.     

南京农业发展思路的定位分析

阐述了农业发展思路中定位的重要性，认为南京农业发展应定位于市场资源型、现代城郊型与都市开发型等３个层次。     

小麦的春化阶段与穗的发育

在宁夏银川地区三年(1983～1985)田间试验的结果表明,小穗原基出现是小麦通过春化阶段的形态标志。小穗原基出现之前,生长锥上的突起均属叶性器官原基。温度作为春化阶段的必要条件,从出苗到生长锥伸长表现为积温效应,从生长锥伸长到小穗原基出现表现为低温效应。     

回应时代呼唤担当历史重任——析“三个代表”重要思想的出发点、着眼点

“三个代表”重要思想反映了当今世界和中国的发展变化对党和国家的新要求,是在科学判断党的历史方位的基础上提出的,是坚持和发展社会主义的必然要求,是我们党艰辛探索和伟大实践的必然结论。     

玉米幼苗不同叶位叶片叶绿素含量和荧光参数特性研究

以玉米幼苗刚好完全展开的1～5叶位叶片为材料,通过检测叶绿素含量和荧光参数特性,研究玉米不同叶位叶片的光化学活性.结果表明:随着叶位的上升,叶绿素含量逐渐增加;与第1,2位叶比,第4,5位叶具有更高的Fv/ Fm和ETo/RC,即第4,5位叶具有更强的光化学活性.