草鱼免疫防病技术操作方法     

黄明  丁庆忠  李发  杨书旺 《北京农业》2009,(30)

草鱼免疫保证有效抗原和防止抗原流失,是免疫成功的关键;组织免疫服务队伍是持久普及推广免疫防病技术的保证措施。  相似文献   

钢筋混凝土结构锈蚀损伤定位     

吴瑾  程吉昕  陆明生 《勤云标准版测试》2004,(4)

对钢筋混凝土结构锈蚀损伤定位进行了研究,以频率变化平方比作为锈蚀损伤参数,从理论上证明该参数是锈蚀损伤位置的函数。锈蚀钢筋混凝土结构试验结果表明预测的损伤位置和实际的损伤位置较一致,模态参数用于检测混凝土结构构件中的损伤,为大型结构的鉴定和评估提供了新的途径。  相似文献   

椰心叶甲发育的起点温度和有效积温   总被引：8，自引：0，他引：8  

钟义海  伍筱影  刘奎  赵志英  彭正强  吴坤宏 《热带作物学报》2004,25(2):47-49

通过室内饲养观察，测定了不同温度下椰心叶甲不同虫态发育的起点温度、有效积温及存活率。结果表明，椰心叶甲世代发育起点温度为11．08℃，有效积温为966．22℃，在海南省儋州市1a发生的理论代数为4～5代。持续过高温度，如32℃不适宜椰心叶甲的生长。  相似文献   

天山云杉人工幼林树冠结构及其在林分间伐中的应用研究     

罗明灿  张瑛山 《新疆农业大学学报》1994,(4)

本文对天山云杉人工幼林树冠结构以及树冠结构与林木之间的关系进行了研究，并基于生物学原理，在确定有效树冠的法础上，通过决定林木能力的树冠特征对其人林分间伐中的应用进行了初步研究。  相似文献   

浙农大A系意蜂生产性能考察试验报告   总被引：5，自引：0，他引：5  

沈基楷  肖体元 《中国蜂业》1993,(1):4-6

用杂交一代蜂群进行对比试验的结果表明,浙农大 A 系意蜂的产育力、群势增长速度、采蜜量等,与平湖意蜂和澳大利亚意蜂无显著差异或基本一致,但蜂王浆高产性能表现突出,产量比平湖意蜂高19.5%,比澳意高42.5%,而且质量指标符合国家规定和出口标准。  相似文献   

Predicting effective doses for the joint action of two fungicide applications   总被引：1，自引：0，他引：1  

N. D. Paveley †  J. M. Thomas  T. B. Vaughan  N. D. Havis  D. R. Jones 《Plant pathology》2003,52(5):638-647

A function was derived to predict fungicide efficacy when more than one application of a single active ingredient is made to a crop, given parameters describing the dose–response curves of the component single-spray applications. In the function, a second application is considered to act on that proportion of the total pathogen population which was uncontrollable at the time of the first application (represented by the lower asymptote of the dose–response curve for the first treatment), plus any additional part of the population which survived the first application as a result of a finite dose being applied. Data to estimate the single-spray dose–response curve parameters and validate predictions of two-spray programme efficacy were obtained from separate subsets of treatments in four field experiments. A systemic fungicide spray was applied to wheat at a range of doses, at one or both of two times (t₁ and t₂), in all dose combinations. Observed values of the area under the disease progress curve (AUDPC) for septoria leaf blotch (Mycosphaerella graminicola) were used to construct response surfaces of dose at t₁ by dose at t₂ for each culm leaf layer. Parameters were estimated from single-spray and zero-dose treatment data only. The model predicted a high proportion (R² = 71–95%) of the variation in efficacy of the two-spray programmes. AUDPC isobols showed that the dose required at t₂ was inversely related to the dose at t₁, but the slope of the relationship varied with the relative timings of t₁ and t₂ in relation to culm leaf emergence. Isobols were curved, so the effective dose – the total dose required to achieve a given level of disease suppression – was lower when administered as two applications.  相似文献   

有效碳数法研究及其在农药气相色谱分析中的应用   总被引：2，自引：0，他引：2  

刘绍仁  叶纪明 《农药科学与管理》1997,18(4):5-9

有机化合物结构与其所含有的有效碳数有一定的关系，本文给出了２０类结构化合物及其所含有有效碳数的关系，并对理论计算值和实测值进行了比较，结果十分接近，利用有效碳数法可以设计农药分析实验方案和无标样的情况下测定农药杂质含量。  相似文献   

有效体育教学模式的创建与实施*     

张细谦 《上海交通大学学报(农业科学版)》2015,(1):106-109

有效体育教学的内涵主要包括三个方面，即，体育教学要重效果，体育教学要好效益，体育教学要高效率。有效体育教学模式是指在“健康第一”思想指导下相对稳定的一种教学程序，其创建步骤主要包括确立教学指导思想、明晰目标内涵、分析教学情境、编选教学内容、创设运作程式。有效体育教学模式的实施要全程渗透健康引领的价值观念，细化体育教学有效性的指标体系，加强教师的有效指导，激活学生的主体参与。  相似文献   

Effects of Rice Variety and Growth Location in Cambodia on Grain Composition and Starch Structure简     

Seila SAR  Morgan J. TTZZOTTT  Jovin HASJTM  Robert G. GTLBERT 《水稻科学》2014,21(1):47-58

The effects of variety and growth location on grain composition and starch structures were investigated using three rice (Oryza sativa L.) cultivars (Phka Romduol, Sen Pidao and IR66) with different amylose contents. All the three cultivars were planted in three different agro-climatic zones (Phnom Penh, Coastal and Plateau) of Cambodia. The protein content of polished grains increased when rice was planted at a location with higher average temperature, but their lipid content decreased. The amylose content and degree of branching were not greatly affected by the minor temperature differences among the growing locations. Starch fine structures characterized by the chain-length distribution were significantly different among the cultivars, but not significantly among different locations. The results suggested that protein and lipid biosyntheses were more sensitive to the environmental temperature than that of starch in rice grains.  相似文献   

沈阳铁西区装备制造产业聚集实证分析     

刘湛 《农业机械化与电气化》2014,(6):20-23

铁西区通过打造装备制造业产业聚集区。形成了高档数控机床、通用石化装备等六大主导产业以及电气及新能源等五大千亿产业集群，成为我国老工业基地振兴的区域典范。介绍铁西装备制造业聚集区发展现状，采用区位熵法测算沈阳装备制造业的产业集中度，对全市装备制造业的现状及问题进行分析，得出相应结论。  相似文献