兔轮状病毒(lapine rotavirus,LaRV)和兔肠冠状病毒(rabbit enteric coronavirus,RECV)是引起兔腹泻的重要病原,2种病毒引起的仔兔腹泻症状极为相似.为建立能同时鉴别LaRV、RECV的方法,根据LaRV和RECV基因组的保守区段设计2对特异性引物,预期特异性扩增LaRV和RECV的片段大小分别为291 bp和163 bp,经优化反应条件,成功建立了 LaRV和RECV的双重RT-PCR检测方法.特异性检测结果显示,能特异性的扩增出LaRV和RECV的目的条带,与兔瘟、大肠杆菌、魏氏梭菌、沙门菌、泰泽菌、巴氏杆菌、金黄色葡萄球菌、绿脓杆菌、链球菌、支气管败血波氏杆菌均无交叉反应;LaRV和RECV的最低检出限分别为2.73×105,1.22×104拷贝/μL,在相同条件下重复可获得一致的结果.对采自山东部分地区的107份兔腹泻样品的检测结果显示,LaRV和RECV的阳性率分别为10.28％和7.48％,两者与单一 RT-PCR检测结果相一致.结果表明,所建立的双重RT-PCR方法能够快速、准确的对LaRV和RECV单一或混合感染的样品进行检测,为LaRV和RECV的鉴别诊断和流行病学调查提供新的技术手段.
When we study on the problem of forest canopy intercepting rainfall, the canopy interception and interception percentage used to be the index and the canopy interception capacity is proposed recently. Combined with the rainfall interception data of Abies fabri forest on Gongga mountain, we describe the concept of capacity of canopy interception and method to measure the capacity of canopy interception approximately. At the same time, we compare the features of three indexes and the results showed that the interception capacity as the index is reasonable and feasible and the interception capacity not only can fully reveal the ability of rainfall interception by forest canopy but also can be used to compare the abilities of different forest-stands. At the same time, the relationship between interception capacity and rainfall can be expressed by function formula, whose parameters can reflect the characteristics of canopies.
[目的]为了克服在林(树)冠截留降雨研究中采用“截留率”和“实测截留量”指标的缺陷.[方法]提出了截留容量的概念及近似确定方法.利用两个林分的实测资料,进一步介绍了截留容量的近似确定方法并进行相互比较.[结果]截留容量更能体现林冠对降雨截留作用的大小,它不仅能在不同林分或树种之间进行截留作用大小的比较,而且不受地域限制.[结论]采用截留容量指标比较不同林分之间对降雨的截留作用不仅是有效的,也是合理的.
The conception of concentration curve is introduced into linear time-invariant concentration system.The definition and interrelation of concentration curve are given and the interrelation fits for linear time-invariant concentration system.In the meantime,dimension of concentration curve are explained.That basic unit-hydrograph(interval unit-hydrograph in the past) is considered as non-dimension is not suitable.However,basic unit-hydrograph should have discharge dimension,namely,m3/s.The basic unit-hydrograph can be used to calculate the concentration of surface net rainfall.
