六方(四方)形摇臂式喷头喷洒效果分析(三)   总被引：3，自引：2，他引：3  

邓鲁华  郝培业 《节水灌溉》2003,(4):11-14

介绍了利用MATLAB软件，采用解析算法编制程序对六方(四方)形摇臂式喷头单喷头喷洒实验数据进行的分析处理，以及对该型喷头不同形式喷灌组合的喷灌效果进行的分析，讨论了现在比较流行的MATLAB软件在喷头实验数据处理及分析方面的应用及其优点。  相似文献   

香蕉弄蝶卵的空间分布格局研究   总被引：5，自引：0，他引：5  

陆永跃  方楚明  沈叔平  梁剑浩 《仲恺农业技术学院学报》2003,16(4):17-20

采用系统调查的方法对香蕉弄蝶(ErionotatorusEvans)卵在香蕉园的空间分布格局进行了研究.结果表明,香蕉弄蝶卵在香蕉园呈聚集分布,建立了Iwaom m回归模型和Taylor幂模型分别为m =1 528+0 873m、log(s2)=0 324+0 821log(m).丛生指数、聚块性指数随着卵密度增大而逐渐减小,且趋于稳定.建立了最适理论抽样数公式为N=22 563×(2 528÷m-0 127),并给出了不同密度、不同准确度要求下的最适抽样株数,为该虫的田间卵密度调查提供了依据.  相似文献   

Early Generation Selection for Grain Yield in Narrow-Leaf Lupin (Lupinus angustifolius L.)     

M. Ratinam  N. Thuriling 《Plant Breeding》1989,102(3):237-247

Experiments were undertaken to identify an efficient method of selection for yield in early segregating generations of narrow-leaf lupin crosses. A first series of experiments involved simulation of F₂ populations with mixtures of ten cultivars and advanced breeding lines. The performance of genotypes in mixtures sown at different densities was compared with their monoculture [commercial density) yields m the same and the following year. These comparisons provided a basis for assessing the value of different planting designs and different selection criteria in early generation selection for yield. Correlated monoculture yield responses to simulated selection for single plant yield were similar for the honeycomb design and standard selection procedures at both low and commercial densities. These responses were much higher than that for grid selection in a low density population. Correlated monoculture yield responses to selection for other plant characters were substantial only for flowering time and number of pod bearing branches under certain conditions. These responses were greatest for selection in a low density mixture and in the year following selection. A procedure involving selection of the earliest flowering plants and selection within this group of plants with the highest number of pod bearing branches should be an effective approach to early generation yield selection in the narrow-leaf lupin.  相似文献   

Honeycomb selection for yield in early generations of spring wheat     

D. M. Lungu  P. J. Kaltsikes  E. N. Larter 《Euphytica》1987,36(3):831-839

Summary The effectiveness of the honeycomb selection method for yield in spring wheat (Triticum aestivum L.) was evaluated using progenies from two wheat crosses, Glenlea x NB131 and Glenlea x Era. Honeycomb selection was carried out in the F₂ and F₃ generations, grown at the University of Manitoba in the summers of 1980 and 1981, respectively. In both generations, divergent selection was made for both high and low yield. Plants selected in the F₃ generation were entered in an F₄ yield test in the summer of 1982. Results of the experiment showed that honeycomb selection for yield in the F₂ and F₃ generations was effective in identifying parents of high- and low-yielding lines. F₃ plants from highyielding F₂ selections gave higher yields than those from low-yielding F₂ selections by 11.5% and 13.0% for Glenlea x NB131 and Glenlea x Era crosses, respectively. The F₄ yield test showed that high yielding selections from both crosses significantly outyielded by 8.9% low yielding selections and by 14.4% the unselected composite lines. It is concluded that the honeycomb selection method can be used for early generation selection in spring wheat.  相似文献   

意大利蜜蜂陈年巢脾水提和醇提液抗菌活性的比较          下载免费PDF全文

程茂盛  琚大伟  殷玲  吉挺  余林生  刘在芳  刘苏燕 《安徽农业大学学报》2011,38(5):683-687

分别采用滤纸扩散法和试管二倍稀释法测定了意大利蜜蜂陈年巢脾(已使用3年)水提液和醇提液对金黄色葡萄球菌、表皮葡萄球菌、铜绿假单胞菌、乙型溶血性链球菌、肺炎链球菌的抑制作用和抑菌效果。结果表明,意大利蜜蜂陈年巢脾水提液和醇提液均对试验菌株有良好的抑制效果,且醇提液抑菌效果优于水提液。  相似文献   

六角形网目围网特性分析   总被引：1，自引：0，他引：1  

冯维山 《大连水产学院学报》1988,(Z1)

六角形网目围网首先在挪威试验研究成功,十几年来在北欧几个国家中较普遍使用,围扑毛魿鱼、鲐鱼、鲱鱼和鳕鱼等.这种新型围网在作业中显示出比传统的四角形网目围网更良好的渔捞性能.本文采用与四角形网目围网对比的方法.在理论上分析了六角形网目围网的网线用量、工作高度、网线张力、上纲网圈变形,网衣形成最大高度时间等特性,指出了如何利用六角形网目的特点设计六角形网目围网技术参数的理论依据。  相似文献   

JZ_1型多功能电子时控巢础埋线机     

缪晓青 《福建农林大学学报(自然科学版)》1988,(1)

本机采用电子时控电路在巢框线上直通8A 左右电流,使框线埋入巢础中。每框埋线约需2秒钟,埋1万框线耗电0.44度,快速、省电,且质量优越。同时还可用作废脾快速卸框和提供2～13V 直流电源蓄电池充电等.整机体积700×380×90mm,造价低,操作简便。  相似文献   

不同洗涤蜂窝煤灰渣对污染土壤中铅的稳定作用研究   总被引：1，自引：0，他引：1  

李立平  席欢  邢维芹  向国强  张科  胡昌乾 《农业环境科学学报》2012,31(6):1124-1130

蜂窝煤灰渣具有稳定污染土壤中铅的作用,但可增大土壤pH和电导率(EC)。将蜂窝煤灰渣经过水洗和稀盐酸酸洗后加入铅污染土壤(1000mg·kg-1Pb),研究了不同处理灰渣对铅有效性和土壤性质的影响。结果表明,灰渣经水洗和酸洗后,其pH(分别下降1.94、3.70)和电导率(0.785、0.890mS·cm-1)明显下降,重金属有效性和全量也有一定程度的下降。水洗和酸洗灰渣加入土壤后,土壤磷有效性有一定的上升。污染土壤在未加磷条件下加入原灰渣、水洗灰渣和酸洗灰渣后,DTPA-Pb含量分别下降67.2、195、117mg·kg-1,加磷情况下加入这3种灰渣土壤DTPA-Pb含量分别降低102、91.8、86.8mg·kg-1,各处理与对照的差异均达到0.05的显著水平。连续提取的结果表明,不同处理对土壤铅形态的影响不明显。  相似文献   

The effect of interplant distance on the effectiveness of honeycomb selection in spring rye. III. Accumulated results of five selection cycles     

A. Bussemakers  I. Bos 《Euphytica》1999,105(3):229-237

The effect of interplant distance on the efficiency of mass selection was studied by performing five cycles of honeycomb selection at two interplant distances (d), i.e. d = 100 cm (low plant density, implying absence of interplant competition) and d = 15 cm (high plant density, implying presence of intergenotypic competition). The offspring of plants selected either at low or at high plant density were compared, both at high plant density and at low plant density, with the original population (in fact: offspring of plants taken at random from this population). At high plant density offspring of plants selected at high density performed better than the original population for most of the characters recorded on a per plant basis. At low plant density offspring of plants selected either at high or at low density performed better than the original population for the characters recorded on a per plant basis. The selections differed, however, significantly from each other: the offspring of plants selected at low density performed better. As the latter did not occur at high density genotype × density interaction was indicated. It is concluded that mass selection should be applied at the plant density used in commercial practice. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

六角形目和无结菱形目经编网片阻力性能与运动变化的比较     

许永久  黄洪亮  宋伟华  冯春雷  周爱忠  王磊 《海洋渔业》2009,31(3):300-307

通过水槽模型实验,对六角形目经编网片(RHN)和无结菱形目经编网片(KRNDM)不同流速(V,0.5、0.75、1.0、1.25、1.5、1.75、2.0 kn)、不同横向缩结系数(Et,0.60、0.65、0.707)下的网片阻力性能和运动变化进行了比较分析。结果如下:(1)网片固定时,六角形目网片阻力较大,无结菱形目网片阻力较小。在横向缩结系数范围(0.60~0.707)内,无结菱形目网片的阻力随着Et增大而逐渐减小,六角形目网片阻力则与Et变化无明显相关。(2)相同Et时,六角形目网片阻力始终较无结菱形目网片阻力大,且与无结菱形目网片之间的阻力差值随流速的增加逐渐增大。(3)Et对于水平位移和垂直位移的影响随网片的结构差异而不同。相同Et时,六角形目网片的水平位移均较大,无结菱形目网片较小。在设计选用网箱网片时(Et,0.60~0.707),首先应考虑网片网目结构和网线粗度,其次考虑横向缩结系数。  相似文献