期刊文献+
共找到4篇文章
< 1 >
每页显示 20 50 100
基于多尺度脑网络局部特征的抑郁症分类 被引量:2
1
作者 曹敏娜 陈俊杰 郭浩 《计算机工程与设计》 北大核心 2018年第12期3712-3716,共5页
为克服传统使用单一尺度的脑网络特征进行精神疾病分类的局限性,提升抑郁症临床诊断率,对使用静息态功能磁共振成像数据得到的多尺度脑网络局部特征分类进行研究。通过将影像划分为不同规模的区域,构建不同尺度的脑网络;在利用统计分析... 为克服传统使用单一尺度的脑网络特征进行精神疾病分类的局限性,提升抑郁症临床诊断率,对使用静息态功能磁共振成像数据得到的多尺度脑网络局部特征分类进行研究。通过将影像划分为不同规模的区域,构建不同尺度的脑网络;在利用统计分析对不同尺度网络下的局部属性进行特征选择的基础上,用支持向量机对抑郁症患者与正常被试进行分类并验证尺度的影响因素。实验结果表明,小尺度脑网络的分类准确率高于大尺度分类准确率,尺度减小带来有效特征数的提升会影响分类结果,进一步验证了尺度划分在脑网络数据分类中的重要性。 展开更多
关键词 抑郁症 功能磁共振成像 脑网络 多尺度 特征选择 支持向量机
下载PDF
纸木蜂窝板面外静态压缩有限元仿真分析
2
作者 曹敏娜 杨国超 张求慧 《包装工程》 CAS 北大核心 2023年第9期199-205,共7页
目的探究纸木蜂窝板的压溃模式和单个蜂窝单元的变形失效模式,为纸木蜂窝板内部失效机制提供一定的理论基础。方法通过有限元仿真模拟,分析面外静态压缩得到变形云图、应力–应变云图和应力–应变曲线。结果纸木蜂窝板的受压过程分为4... 目的探究纸木蜂窝板的压溃模式和单个蜂窝单元的变形失效模式,为纸木蜂窝板内部失效机制提供一定的理论基础。方法通过有限元仿真模拟,分析面外静态压缩得到变形云图、应力–应变云图和应力–应变曲线。结果纸木蜂窝板的受压过程分为4个阶段,应力集中分布在蜂窝芯层,最外侧的蜂窝最早出现变形且变形较大,随后中间区域的蜂窝逐步变形增大。蜂窝芯层在受压时存在至多1个应力峰,蜂窝壁弯曲折叠了1~2次,产生了1~2个塑性铰,并在此过程中吸收能量。结论纸木蜂窝板的压溃失效趋势为由外侧蜂窝向内部蜂窝,由单层壁向双层壁,由最弱的压溃点向其余位置。 展开更多
关键词 纸木蜂窝板 蜂窝芯层 面外静态压缩 有限元
下载PDF
Nitrogen Doped Carbon as Efficient Catalyst toward Oxygen Reduction Reaction 被引量:4
3
作者 YANG Wei-Guang GONG Zhi-Wei +3 位作者 CHEN Yan-Ning CHEN Ru-Ru MENG Dong-Li cao min-na 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2020年第2期287-293,186,共8页
A kind of nitrogen-doped carbon(NC) nanomaterials was prepared via calcining the nitrogen-rich organic molecular glycoluril under nitrogen atmosphere. Elemental analysis result indicates the N content of the obtained ... A kind of nitrogen-doped carbon(NC) nanomaterials was prepared via calcining the nitrogen-rich organic molecular glycoluril under nitrogen atmosphere. Elemental analysis result indicates the N content of the obtained NC is 13.9 wt.%. Electrochemical measurement demonstrated that the obtained NC catalyst is an efficient ORR electrocatalyst in alkaline electrolyte. The process of ORR is dominated by a four-electron transfer pathway with the most efficient catalytic activity. In addition, the NC catalyst exhibits excellent stability and good resistance to methanol poisoning. After 10000 s of chronoamperometric durability test, the relative current of NC catalyst retained as high as 95%. This work provides a new strategy for the preparation of cost-effective ORR catalysts with high catalytic performance. 展开更多
关键词 NITROGEN-DOPED CARBON OXYGEN reduction reaction ELECTROCHEMICAL CATALYSIS
原文传递
Synthesis and Crystal Structure of a New Noble Metalcontaining Supramolecular Self-assembly with Decamethylcucurbit[5]uril
4
作者 CHEN Ru-Ru YANG Wei-Guang +1 位作者 cao min-na LI Hong-Fang 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2020年第3期535-542,379,共9页
A new supramolecular self-assembly [Li(H2 O)2]2[(H2 O@Me10 CB[5])][PtC l6]·7 H2 O(1, Me10 CB[5] = decamethylcucurbit[5]uril), has been successfully constructed with Me10 CB[5] and [PtCl6]^(2-) anion in the presen... A new supramolecular self-assembly [Li(H2 O)2]2[(H2 O@Me10 CB[5])][PtC l6]·7 H2 O(1, Me10 CB[5] = decamethylcucurbit[5]uril), has been successfully constructed with Me10 CB[5] and [PtCl6]^(2-) anion in the presence of lithium cation(Li+). Single-crystal X-ray diffraction study reveals that compound 1 crystallizes in monoclinic space group P21/n with a = 11.1681(18), b = 28.5425(4), c = 18.9342(3) ?, β = 99.0143(15)°, V = 5961.02(16) ?~3, Z = 4, F(000) = 3224, μ = 2.714 mm^(-1), R = 0.0470 and wR = 0.1076(I > 2σ(I)). In the supramolecular self-assembly, two of the portal carbonyl oxygen atoms of Me10 CB[5] are coordinated to Li+ cation, yielding a "half-open" molecular capsule. Then adjacent molecular capsules are connected with each other through hydrogen-bonding to form a one-dimensional(1 D) supramolecular chain structure. The [PtCl6]^(2-) anions are fixed on one side of the 1 D supramolecular chain through supramolecular interactions. The thermal stability, electronic valence and morphology of compound 1 are also investigated. 展开更多
关键词 uril NOBLE metal SUPRAMOLECULAR SELF-ASSEMBLY crystal structure
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部