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Zheng Xiaoxian Liu Donglan College of Forest Resources Environment Beijing Forestry University Beijing P.R.China 《中国林学(英文版)》1996,(1)
该文探讨了不用编制削度表直接建立高精度立木干曲线的方法.当采用干曲线是3次多项式时,通常根据10分法测定树干各部位直径,用最小二乘法求出该方程式的参数.从数学角度,只要知道树干任意3个部位的直径,就可以用最小二乘法或联立方程式求解干曲线参数.本文以樟子松为例,探讨用树干哪3个部位直径拟合的干曲线最接近实际干曲线,为建立立木干曲线提供有效方法.利用9个部位半径(方法Ⅰ)和利用其中3个部位半径(方法Ⅱ,28种组合)分别拟合干曲线,结果表明方法Ⅱ的6种半径组合的精度良好,其中的3种组合,(r1.3,r0.3,r0.7),(r1.3,r0.4,r0.7)和(r1.3,r0.4,r0.8)是拟合现实干曲线的有效方法. 相似文献
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Lack of effect of recombinant bovine interferon alpha I1 in the treatment of experimentally-induced bovine warts. 下载免费PDF全文
Fifteen four-month old calves were inoculated, on five scarified sites on each side of the neck, with a suspension of ground wart tissue from a steer naturally infected with bovine papilloma virus 1. Warts started to appear about one month postinfection and were measurable in ten calves two months postinfection, when the trial started. After stratification on the size of the warts, all fifteen calves were allocated randomly to one of the following treatment groups: twice weekly intramuscular injections of 5 mg recombinant bovine interferon alpha I1 (rBoIFN alpha I1), weekly injection of 5 mg of rBoIFN alpha I1 or placebo, for three weeks. The biggest wart on each calf at the beginning of the trial was measured and photographs of all warts were taken weekly for five weeks. An analysis of covariance on the log of the volumes of warts during the five weeks of the trial showed a significant difference between groups (p = 0.026). Warts in treated groups tended to grow faster than in the placebo group. 相似文献
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The rice( Oryza L. ) variety, Lijiangxintuanheigu(LTH), is a universally susceptible variety. A set of near-isogenic lines (NILs) of rice which has single resistance gene for each line was developed by use of LTH as recurrent parent and Kusabue,Tsuyuake, K1, PiNo. 4, K60 and BL1, which are from Kiyosawa‘s differential varieties(KDV), as donor parents. Differentiating ability of these NILs to Philippine isolates was compared with that of their donor parents, KDV and IRRI‘ s NILs. The results of comparative studies were as follows: (1) Differentiating ability of Chinese NILs to Philippine isolates was much stronger than that of their donor parents and that of KDV. (2) Chinese NILs had similar ability to differentiate races to IRRI‘s NILs or higher differentiating ability than them. But IRRI‘s NILs almost had no differentiating ability to isolates from japonica rice-growing regions. They can not be used to differentiate races of isolates from japonica ricegrowing regions. Whereas, Chinese NILs can be used to differentiate races of isolates from both japonica ricegrowing regions and indica rice-growing regions. It was concluded that the set of Chinese NILs can be used as international differentials. 相似文献
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抗大肠埃希氏菌粘附素单克隆抗体诊断试剂的研制及其现场初步应用 总被引:1,自引:0,他引:1
作者从所研制的抗产肠毒素性大肠埃希氏菌(ETEC)粘附素K_(88)、K_(99)、987P和F_(41)单克隆抗体(以下简称单抗)44株中的7株,建立了检测以上粘附素抗原的单抗诊断试剂,并确定了以4单抗和3单抗夹心ELISA为特征的检测大批量临床样品的诊断方法与程序,对1038例自然发生下痢仔猪粪样ETEC粘附素的检测结果表明,本试验所建立的诊断方法与程序,具有敏感、准确、快速和简便的特点。 相似文献