以1/2Hoagland营养液为基础培养液,研究了在0.1%、0.2%、0.4%和0.6% NaCl胁迫条件下,毛红椿[Toona ciliata Roem. var. pubescens （Franch.） Hand.-Mazz.]和水松[Glyptostrobus pensilis （Staunt. ex D. Don） K. Koch]的种子萌发和...以1/2Hoagland营养液为基础培养液,研究了在0.1%、0.2%、0.4%和0.6% NaCl胁迫条件下,毛红椿[Toona ciliata Roem. var. pubescens （Franch.） Hand.-Mazz.]和水松[Glyptostrobus pensilis （Staunt. ex D. Don） K. Koch]的种子萌发和幼苗生长情况.结果表明,随着NaCl浓度的增加,2个树种的种子萌发率和简化苗木活力指数均明显下降,在0.1%、0.2%、0.4%和0.6% NaCl胁迫条件下, 毛红椿和水松种子的最终萌发率分别为89.3%、87.3%、62.7%、32.0%和26.0%、16.7%、6.0%、3.3%,简化苗木活力指数分别为1.39～0.08和1.52～0.07,且毛红椿的种子萌发率和简化苗木活力指数均明显高于水松.萌发恢复实验结果表明,高浓度NaCl处理后的种子具有较高的萌发恢复率.根据实验结果初步判定毛红椿种子具有较强的耐盐性.展开更多
This paper proposes an efficient retrieval ap- proach for iris using local features. The features are extracted from segmented iris image using scale invariant feature trans- form （SIFT）. The keypoint descriptors ex...This paper proposes an efficient retrieval ap- proach for iris using local features. The features are extracted from segmented iris image using scale invariant feature trans- form （SIFT）. The keypoint descriptors extracted from SIFT are clustered into m groups using k-means. The idea is to perform indexing of keypoints based on descriptor property. During database indexing phase, k-d tree k-dimensional tree is constructed for each cluster center taken from N iris im- ages. Thus for m clusters, rn such k-d trees are generated de- noted as ti, where 1 ~〈 i ~〈 m. During the retrieval phase, the keypoint descriptors from probe iris image are clustered into m groups and ith cluster center is used to traverse correspond- ing ti for searching, k nearest neighbor approach is used, which finds p neighbors from each tree （ti） that falls within certain radius r centered on the probe point in k-dimensional space. Finally, p neighbors from m trees are combined using union operation and top S matches （S c_ （m x p）） correspond- ing to query iris image are retrieved. The proposed approach has been tested on publicly available databases and outper- forms the existing approaches in terms of speed and accuracy.展开更多
文摘以1/2Hoagland营养液为基础培养液,研究了在0.1%、0.2%、0.4%和0.6% NaCl胁迫条件下,毛红椿[Toona ciliata Roem. var. pubescens （Franch.） Hand.-Mazz.]和水松[Glyptostrobus pensilis （Staunt. ex D. Don） K. Koch]的种子萌发和幼苗生长情况.结果表明,随着NaCl浓度的增加,2个树种的种子萌发率和简化苗木活力指数均明显下降,在0.1%、0.2%、0.4%和0.6% NaCl胁迫条件下, 毛红椿和水松种子的最终萌发率分别为89.3%、87.3%、62.7%、32.0%和26.0%、16.7%、6.0%、3.3%,简化苗木活力指数分别为1.39～0.08和1.52～0.07,且毛红椿的种子萌发率和简化苗木活力指数均明显高于水松.萌发恢复实验结果表明,高浓度NaCl处理后的种子具有较高的萌发恢复率.根据实验结果初步判定毛红椿种子具有较强的耐盐性.
文摘This paper proposes an efficient retrieval ap- proach for iris using local features. The features are extracted from segmented iris image using scale invariant feature trans- form （SIFT）. The keypoint descriptors extracted from SIFT are clustered into m groups using k-means. The idea is to perform indexing of keypoints based on descriptor property. During database indexing phase, k-d tree k-dimensional tree is constructed for each cluster center taken from N iris im- ages. Thus for m clusters, rn such k-d trees are generated de- noted as ti, where 1 ~〈 i ~〈 m. During the retrieval phase, the keypoint descriptors from probe iris image are clustered into m groups and ith cluster center is used to traverse correspond- ing ti for searching, k nearest neighbor approach is used, which finds p neighbors from each tree （ti） that falls within certain radius r centered on the probe point in k-dimensional space. Finally, p neighbors from m trees are combined using union operation and top S matches （S c_ （m x p）） correspond- ing to query iris image are retrieved. The proposed approach has been tested on publicly available databases and outper- forms the existing approaches in terms of speed and accuracy.
