根据ROI(Region of Interest)面积给出了等距三重优化覆盖此ROI所需要的信标发射位置数量计算方法;随后对矩形ROI提出了一种简单的信标发射位置确定方法;针对现有的遍历发射位置点的路径遍历算法的不足,提出了一种新的应用蚁群算法的信...根据ROI(Region of Interest)面积给出了等距三重优化覆盖此ROI所需要的信标发射位置数量计算方法;随后对矩形ROI提出了一种简单的信标发射位置确定方法;针对现有的遍历发射位置点的路径遍历算法的不足,提出了一种新的应用蚁群算法的信标发射位置点的遍历算法,并利用该算法对基于三边测量方法进行传感器节点定位。仿真实验表明,采用该文提出的方法对传感器节点进行定位,在定位的精度和定位的效率方面与现存的方法相比有明显的提高。展开更多
采用两步 PCR法成功地克隆了一个全长的 c DNA.首先 ,用差式分析法克隆得到差别表达的 c DNA片段 ,再分别用这些片段内部的特异序列及 c DNA两端不同接头的序列为引物进行第一步 PCR扩增 ,得到差别 c DNA片段的上游和下游序列 .然后 ,...采用两步 PCR法成功地克隆了一个全长的 c DNA.首先 ,用差式分析法克隆得到差别表达的 c DNA片段 ,再分别用这些片段内部的特异序列及 c DNA两端不同接头的序列为引物进行第一步 PCR扩增 ,得到差别 c DNA片段的上游和下游序列 .然后 ,根据第一步 PCR扩增得到的上游和下游序列设计基因特异的引物进行第二步 PCR,从而得到全长的 c DNA.展开更多
PPF1 is a vegetative growth related gene that encodes a putative membrane protein having high homology with Arabidopsis chloroplast thylakoid protein ALB3. Immunoelectron microscopic assay showed that PPF1 was mainly ...PPF1 is a vegetative growth related gene that encodes a putative membrane protein having high homology with Arabidopsis chloroplast thylakoid protein ALB3. Immunoelectron microscopic assay showed that PPF1 was mainly localized in the thylakold membrane and was highly expressed in well-developed chloroplasts of short day (SD) grown G2 pea while having a very low abundance in chloroplasts of long day (LD) grown plants two weeks after flowering. Comparison of the leaf senescence processes in transgenic Arabidopsis and wild type plants revealed that overexpression of PPF1 delayed leaf senescence, while the depression of its Arabidopsts homologue (ALB3) with PPF1 antisense mRNA accelerated leaf senescence obviously. Ultrastructural analysis of transgenic Arabidopsis plants showed that when PPF1 was overexpressed in Arabidopsis, the chloroplasts were bigger and had much more grana and stroma thylakoid membranes than those of wild type plants. On the contrary, when PPF1 was expressed in antisense orientation to reduce the level of PPF1 homologue in Arabidopsis, the transgenic plants had smaller chloroplasts With less grana. and poorly developed thylakoid membrane systems. These results suggested that the developmental status of chloroplasts was positively correlated with the level of PPF1 or its Arabidopsts homologue, ALB3. Our results suggested that PPF1 gene might regulate plant development by controlling chloroplast development.展开更多
文摘根据ROI(Region of Interest)面积给出了等距三重优化覆盖此ROI所需要的信标发射位置数量计算方法;随后对矩形ROI提出了一种简单的信标发射位置确定方法;针对现有的遍历发射位置点的路径遍历算法的不足,提出了一种新的应用蚁群算法的信标发射位置点的遍历算法,并利用该算法对基于三边测量方法进行传感器节点定位。仿真实验表明,采用该文提出的方法对传感器节点进行定位,在定位的精度和定位的效率方面与现存的方法相比有明显的提高。
文摘采用两步 PCR法成功地克隆了一个全长的 c DNA.首先 ,用差式分析法克隆得到差别表达的 c DNA片段 ,再分别用这些片段内部的特异序列及 c DNA两端不同接头的序列为引物进行第一步 PCR扩增 ,得到差别 c DNA片段的上游和下游序列 .然后 ,根据第一步 PCR扩增得到的上游和下游序列设计基因特异的引物进行第二步 PCR,从而得到全长的 c DNA.
文摘PPF1 is a vegetative growth related gene that encodes a putative membrane protein having high homology with Arabidopsis chloroplast thylakoid protein ALB3. Immunoelectron microscopic assay showed that PPF1 was mainly localized in the thylakold membrane and was highly expressed in well-developed chloroplasts of short day (SD) grown G2 pea while having a very low abundance in chloroplasts of long day (LD) grown plants two weeks after flowering. Comparison of the leaf senescence processes in transgenic Arabidopsis and wild type plants revealed that overexpression of PPF1 delayed leaf senescence, while the depression of its Arabidopsts homologue (ALB3) with PPF1 antisense mRNA accelerated leaf senescence obviously. Ultrastructural analysis of transgenic Arabidopsis plants showed that when PPF1 was overexpressed in Arabidopsis, the chloroplasts were bigger and had much more grana and stroma thylakoid membranes than those of wild type plants. On the contrary, when PPF1 was expressed in antisense orientation to reduce the level of PPF1 homologue in Arabidopsis, the transgenic plants had smaller chloroplasts With less grana. and poorly developed thylakoid membrane systems. These results suggested that the developmental status of chloroplasts was positively correlated with the level of PPF1 or its Arabidopsts homologue, ALB3. Our results suggested that PPF1 gene might regulate plant development by controlling chloroplast development.
