查询词典 natural selection

Based on the clonal selection algorithm, with the combination of the dynamic adjustment idea between antibodies of the idiotypic immune network theory, a new immune algorithm, the clonal selection adjustment algorithm, is proposed and applied to the design of IIR digital filter.

在克隆选择算法的基础上，结合独特型免疫网络理论中抗体间的自适应动态调节思想，提出一种新的免疫算法―克隆选择调节算法，并用于IIR数字滤波器的设计。

With this inerratic change for the power of QTL detection,suitable experimental sample size could be roughly determined in practice pursuant to the degree of selection in the population of interest prior to experiment in order that the statistical power for QTh mapping would not decline because of the presence of selection in the population.

这种偏差根本上是由QTL基因型与多基因之间负的连锁不平衡以及QTL与标记之间的连锁不平衡所造成的。 2）目前QTL定位实践已找到了一些具有育种意义的主效位点。

In this study 2mG2-epsps gene was used to be a selection marker gene, and a series of experiments were designed for determining the time of their screening and selection pressure. The results showed that 1 mM glyphosate isopropylamine and 15 days screening can be effectively inhibited non-transgenic maize callus tissue differentiation. So this research work has provided a safe and effective screening system for corn and other monocotyledons crops.

实验中以2mG2-epsps基因作为筛选标记基因，为确定其筛选时间及筛选压力，进行了玉米愈伤组织对不同浓度草甘膦的抗性实验，确定向培养基中添加浓度为1mM的草甘膦异丙胺盐筛选15天能有效的抑制非转基因玉米愈伤组织的分化，本研究的再生植株的阳性率为45%，为玉米及其它单子叶作物转化提供了一种有效、安全的筛选体系。

Libellula had different resistance to different races and Xiannong 4 was susceptible to all the races except CY18 and CY22. Resistant components had significant variances among different cultivars, races and cultivar×race. And Libellula had strong selection on different races, while the selection of Xiannong 4 was weaker than that of Libellula.

里勃留拉的抗性谱较宽，抗病性在小种间差异明显，而咸农4号对除CY18、CY22外的小种均感病；两者的抗病性组分在品种间、小种间以及品种×小种互作时均有显著差异；里勃留拉对不同菌系有较强的选择作用，而咸农4号的选择作用较弱。

According to the absolute value of the coefficient in 3 the principal components,Marmot habitat selection'main factors were elevation、slope gradient、longitude(the absolute value of the coefficient respective were:0.860、0.740、0.712)and so on geography factor.Vegetation height and aboveground biomass have synergistic effect with geography factor.Distance from human disturbance and distance from road(the absolute value of the coefficient respective were:0.814 and 0.820) human activity factor were secondary factor.Vegetation coverage would named vegetation factor (the absolute value of the coefficient was:0.816) have very important influence to Marmota habitat selection.

根据三个主成分中载荷系数绝对值的大小可以判断影响旱獭生境选择的主要生态因子是海拔、坡度、纬度(载荷系数绝对值分别为：0.860、0.740、0.712)等地理因子，草高、地上生物量与地理因子又具有协同效应；距人为干扰距离、距公路距离(载荷系数绝对值分别为：0.814和0.820)人类活动因素是次要因子；盖度(载荷系数绝对值为：0.816)将其命名为植被因子，对旱獭的生境选择也具有重要的影响作用。

Nonsynonymous sites were far less than synonymous sites. The ratio of synonymous and nonsynonymous substitution were all less or equal to one manifesting that it did not effected by Darwin positive selection. But some sites affected by negative selection.

非同义突变位点远少于同义突变位点，同义与非同义替代速率比全部小于或等于1，表明MSTN基因编码区序列并未受到达尔文正向选择的影响，却受到一定的负向选择作用。

Methods Using double selection in the selection of prosthesis,adjusting the position of the pocket for the prosthesis according to the size of the prosthesis,partial undermining the major pectoral muscle and fixing it to the periost of the costal bone.

应用乳房假体容积双重选择法，根据假体大小适当调节假体放置位置并行胸大肌部分剥离胸骨骨膜固定。

Pisang Mas as transformation receptor, and optimized the genetic transformation system of banana from aspects of hygromycin selection concentration and selection method in order to establish a high efficient Agrobacterium tumefaciens-mediated genetic transformation system for banana.

为建立根癌农杆菌介导的香蕉高效遗传转化系统，本研究以雄性花诱导产生的贡蕉胚性悬浮系为转化受体，从潮霉素筛选浓度和筛选方法两方面进行了优化。

This review discusses some technological details and problems, and reviews the progresses, including selection and management of competent cells, optimization of preculture and coculture, selection, foreign gene expression and regulation.

本文综述了近几年来此项研究在感受态细胞选择与调节、预培养及共培养体系优化、转化子的筛选及外源基因表达调控等方面的主要进展。

Factors that influence percentage of transformation including time of preculture, dipping and coculture, type and content of antibiotic, day of delayed selection culture, intension of selection were studied. The effective transformation system of "Starkrimson" was developed as follow: Leaves precultured in darkness for three days were dipped into agrobacterium suspension for three minutes, then were cocultured in darkness on MS medium with TDZ0.5mg/L and NAA 0.3mg/L for three days, and then cultured in darkness on MS medium with TDZ0.5mg/L NAA0.3mg/L and Cef 250mg/L.

通过对叶片预培养时间、侵染时间、共培养时间、抑菌素种类和浓度、延时筛选时间、不同选择压等遗传转化影响因素的研究，建立的'新红星'苹果遗传转化体系为：叶片黑暗预培养3天，经农杆菌侵染3分钟，在含TDZ0.5mg/L，NAA0.3mg/L的MS培养基上黑暗共培养3天，然后加250mg/L Cef黑暗维持培养3天，再进行Km12.5mg/L的选择压黑暗培养至抗性愈伤出现；转为光照条件1-2次的继代筛选，获得抗性芽后，进行扩繁。

Metrorrhagia is also gynaecological problems of common diseases.

崩漏是妇科常见病也是疑难症。

WordFTP gives you the convenience and timesaving you need.

wordftp让您的方便和省时您所需要的。