图神经网络(Graph Neural Networks,GNN)因其结构的新颖性在文本分类任务中广受关注。针对GNN在训练数据集较少时容易出现过拟合、特征信息不足等问题,提出了Att-DASA-ReGNN(Regional Embedding GNN based on Data Augmentation and Sel...图神经网络(Graph Neural Networks,GNN)因其结构的新颖性在文本分类任务中广受关注。针对GNN在训练数据集较少时容易出现过拟合、特征信息不足等问题,提出了Att-DASA-ReGNN(Regional Embedding GNN based on Data Augmentation and Self-Attention with the Attention Mechanisms)模型。该模型在数据特征提取阶段引入了简单数据增强方法(Easy Data Augmentation,EDA)和Self-Attention技术改善了过拟合问题;原模型词嵌入方式对维度很高且稀疏的高阶邻域信息的捕捉能力不足,该模型中通过增加区域词嵌入技术,加强了词级之间的关系,使得模型更容易捕捉高阶邻域信息,从而减轻数据稀疏带来的影响。为了进一步提升模型的文本分类准确率,该模型的图词特征交互阶段通过引入Soft-Attention技术改进了注意力权重提取方式。最后,在多种数据集上的实验证明,该模型的分类准确率较之前模型均有不同程度的提升。展开更多
The crystal structure of the metal-organic frame Ca（C5H9O5）2·CH3OH·2H2O（1） has been synthesized and characterized.Complex 1 belongs to a tetragonal P43212 space group.In complex 1,the sugar moiety shows ...The crystal structure of the metal-organic frame Ca（C5H9O5）2·CH3OH·2H2O（1） has been synthesized and characterized.Complex 1 belongs to a tetragonal P43212 space group.In complex 1,the sugar moiety shows a beta-L configuration of pyranose form.The calcium（Ⅱ） is eight-coordinated,binding to four such sugar moieties,via O（1）,O（2） of two molecules and O（3）,O（4） of the other two,with the 4-hydroxy group being deprotonated.The water and methanol molecules are not coordinated to the calcium ion.展开更多
Four new octadecanoid derivatives(1–4) including a pair of enantiomers(1/2), along with 12 known analogues(5–16), were isolated from the seeds of Ipomoea nil. Their structures were determined by detailed spectroscop...Four new octadecanoid derivatives(1–4) including a pair of enantiomers(1/2), along with 12 known analogues(5–16), were isolated from the seeds of Ipomoea nil. Their structures were determined by detailed spectroscopic analyses and comparison with reported data of structurally related compounds, with the absolute configurations of 1 and 2 being assigned by an in situ dimolybdenum ECD method. Our bioassays revealed that these isolates did not show ABTS radical scavenging activity while 10 and 13 displayed better a-glucosidase inhibitory activity than the positive control acarbose(IC_(50) 167.7 ± 1.55 μmol×L^(-1)), with IC_(50) of 92.73 ± 3.12 and 11.39 ± 2.18 μmol×L^(-1), respectively.展开更多
文摘图神经网络(Graph Neural Networks,GNN)因其结构的新颖性在文本分类任务中广受关注。针对GNN在训练数据集较少时容易出现过拟合、特征信息不足等问题,提出了Att-DASA-ReGNN(Regional Embedding GNN based on Data Augmentation and Self-Attention with the Attention Mechanisms)模型。该模型在数据特征提取阶段引入了简单数据增强方法(Easy Data Augmentation,EDA)和Self-Attention技术改善了过拟合问题;原模型词嵌入方式对维度很高且稀疏的高阶邻域信息的捕捉能力不足,该模型中通过增加区域词嵌入技术,加强了词级之间的关系,使得模型更容易捕捉高阶邻域信息,从而减轻数据稀疏带来的影响。为了进一步提升模型的文本分类准确率,该模型的图词特征交互阶段通过引入Soft-Attention技术改进了注意力权重提取方式。最后,在多种数据集上的实验证明,该模型的分类准确率较之前模型均有不同程度的提升。
基金supported by the Ministry of Science and Technology through the Agriculture Science and Technology Achievements Transformation Fund(No.2013GB23600669)the Science and Technology Planning Project of Guangzhou Municipality,China(No.2011Y2-00012)
文摘The crystal structure of the metal-organic frame Ca（C5H9O5）2·CH3OH·2H2O（1） has been synthesized and characterized.Complex 1 belongs to a tetragonal P43212 space group.In complex 1,the sugar moiety shows a beta-L configuration of pyranose form.The calcium（Ⅱ） is eight-coordinated,binding to four such sugar moieties,via O（1）,O（2） of two molecules and O（3）,O（4） of the other two,with the 4-hydroxy group being deprotonated.The water and methanol molecules are not coordinated to the calcium ion.
基金supported by the Natural Science Foundation of Shandong Province(No.JQ201721)the Young Taishan Scholars Program(No.tsqn20161037)+1 种基金the Director Foundation of XTIPC,CAS(No.2015RC015)Shandong Talents Team Cultivation Plan of University Preponderant Discipline(No.10027)。
文摘Four new octadecanoid derivatives(1–4) including a pair of enantiomers(1/2), along with 12 known analogues(5–16), were isolated from the seeds of Ipomoea nil. Their structures were determined by detailed spectroscopic analyses and comparison with reported data of structurally related compounds, with the absolute configurations of 1 and 2 being assigned by an in situ dimolybdenum ECD method. Our bioassays revealed that these isolates did not show ABTS radical scavenging activity while 10 and 13 displayed better a-glucosidase inhibitory activity than the positive control acarbose(IC_(50) 167.7 ± 1.55 μmol×L^(-1)), with IC_(50) of 92.73 ± 3.12 and 11.39 ± 2.18 μmol×L^(-1), respectively.
