检索结果-南通市图书馆

A New Stilbene from Cercis chinensis Bunge

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2005年第8期47卷 1021-1024页

作者： Yuan LI dong-ming zhang Shi-Shan YU Institute of Materia Medica Chinese Academy of Medical Sciences and Peking Union Medical College Beijing 100050 China

To study new natural products, we used ODS （YMC, Kyoto, Japan） and silica gel column chromatography to separate compounds in Cercis chinensis Bunge （Leguminosae）. A new stilbene, trans- 3, 5, 3＇, 4＇-tetrahydroxy-4-methylstilbene （1）, along with 10 known compounds, namely piceatannol （2）, dihydromyricetin （3）, catechin （4）, dihydrorobinetin （5）, menisdaurin （6）, lithospermoside （7）, teatannin （8）, dasycarponin （9）, β-sitosterol （10）, and daucosterin （11）, was isolated from C. chinensis. Their structures were elucidated on the basis of spectroscopic evidence. Compounds 2-6 and 9 were isolated from the genus Cercis Linn. for the first time.

关键词： Cercis chinensis Leguminosae trans-3, 5, 3', 4'-tetrahydroxy-4-methylstilbene.

Meta-path reasoning of knowledge graph for commonsense question answering

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2024年第1期18卷 49-59页

作者： Miao zhang Tingting HE ming dong National Engineering Research Center for E-Learning Central China Normal UniversityWuhan 430079China Hubei Provincial Key Laboratory of Artificial Intelligence and Smart Learning Central China Normal UniversityWuhan 430079China National Language Resources Monitoring&Research Center for Network Media Central China Normal UniversityWuhan 430079China School of Computer Central China Normal UniversityWuhan 430079China

Commonsense question answering(CQA)requires understanding and reasoning over QA context and related commonsense knowledge,such as a structured Knowledge Graph(KG).Existing studies combine language models and graph neural networks to model ***,traditional knowledge graph are mostly concept-based,ignoring direct path evidence necessary for accurate *** this paper,we propose MRGNN(Meta-path Reasoning Graph Neural Network),a novel model that comprehensively captures sequential semantic information from concepts and *** MRGNN,meta-paths are introduced as direct inference evidence and an original graph neural network is adopted to aggregate features from both concepts and paths *** conduct sufficient experiments on the CommonsenceQA and OpenBookQA datasets,showing the effectiveness of ***,we conduct further ablation experiments and explain the reasoning behavior through the case study.

关键词： question answering knowledge graph graph neural network meta-path reasoning

Two new flavanonol glycosides from Gordonia chrysandra

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2008年第1期19卷 61-64页

作者： Kun Wang Jing Zhi Yang Li Zuo dong ming zhang Institute of Materia Medica Chinese Academy of Medical Sciences and Key Laboratory of BioactiveSubstances and Resources Utilization of Chinese Herbal Medicine （Peking Union Medical College） Ministry of Education 1 Xiannongtan Street Beijing 100050 China

Two new flavanonol glycosides named chrysandrosides A and B were isolated from the roots of Gordonia chrysandra Cowan. Their structures were determined by 1D and 2D NMR, FAB-MS techniques and chemical methods. Chrysandrosides A and B showed pronounced hepatoprotective activities against o-galactosamine （o-GalN）-induced toxicity in rat hepatic epithelial stemlike cells （WB-F344）. 2007 dong ming zhang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

关键词： Gordonia chrysandra Cowan Flavanonol Chrysandrosides A and B

A Novel Phenylpropanoid-substituted Catechin Glycoside and a New Dihydrochalcone from Sarcandra glabra

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2006年第2期17卷 207-210页

作者： Yuan LI dong ming zhang Shi Shah YU Jian Bei LI Yong ming LUO Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine Ministry of Education Institute of Materia Medica Chinese Academy of Medical Sciences and Peking Union Medical College Beijing 100050 Faculty of Pharmacy Jiangxi University of Traditional Chinese Medicine Nanchang 330006

A novel phenylpropanoid-substituted catechin glycoside glabraoside A 1 and a new dihydrochalcone 3＇-（7＂-allylphenyl）-2＇,4＇,4＂-trihydroxy-6＇-methoxydihydrochalcone 2 were isolated from the herbs of Sarcandra gl... 详细信息

关键词： Sarcandra glabra glabraoside A phenylpropanoid-substituted flavan-3-ols dihydrochalcone.

A new benzophenone glycoside from the leaves of Psidium guajava L.

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2011年第2期22卷 178-180页

作者： Hui Zheng Fu Jing Zhi Yang Chuang Jun Li dong ming zhang Institute of Materia Medica Chinese Academy of Medical Sciences and Peking Union Medical College(Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal MedicineMinistry of Education)Beijing 100050China

A new benzophenone glycoside,2,6-dihydroxy-4-O-β-D-glucopyranosylbenzophenone（1）,was isolated from the leaves of guajava *** structure was elucidated by spectral and chemical methods.1 showed significant activities... 详细信息

关键词： Psidium guajava L. Benzophenone glycoside 2,6-Dihydroxy-4-O-β-D-glucopyranosylbenzophenone NO

Guajamers A-I, Rearranged Polycyclic Phloroglucinol Meroterpenoids from Psidium guajava Leaves and Their Antibacterial Activity

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2021年第5期39卷 1129-1137页

作者： Ji-Wu Huang Chuang-Jun Li Jing-Zhi Yang Chuan Li Yu zhang Ke Liu Yue Yu Jian-dong Jiang dong-ming zhang State Key Laboratory of Bioactive Substance and Function of Natural Medicines Institute of Materia MedicaChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100050China

Eight new polycyclic phloroglucinol meroterpenoids guajamers A-H(1-8),a methylated benzoylphloroglucinol meroterpenoid guajamer I(9)representing a new skeleton,and two known analogues(10 and 11)were isolated from the leaves of Psidium *** structures of new molecules were elucidated by detailed analysis of spectroscopic data,and those of 1,2,8,and 9 were unambiguously confirmed by single-crystal X-ray diffraction ***,compounds 1-8 were sesquiterpene and monoterpene-based meroterpenoids with rearranged skeletons,while compound 9 was the first case of 3-alkyl-5-formyl-benzoylphloroglucinol-coupled sesquiterpene containing an unusual C-l-spiro-fused 6/6/9/4 polycyclic *** addition,all the isolated compounds were evaluated for their antibacterial activity against three bacterial strains,and most of them(compounds 2-7,10,and 11)showed antibacterial activity against Staphylococcus aureus and Staphylococcus epidermidis with MIC values of 8-32 μmol/*** findings suggested that meroterpenoids isolated from Psidium guajava can be considered as potential antibacterial leading compounds for pharmaceutical industry.

关键词： Psidium guajava Meroterpenoids X-ray crystal structure Structural elucidation Antibacterial activity

Effect of wire mesh casing treatment on axial compressor performance and stability

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第3期37卷 60-76页

作者： ming zhang Jiaming zhang Jiahao HU Xu dong Dakun SUN Xiaofeng SUN School of Energy and Power Engineering Beihang UniversityBeijing 100191China Beihang Hangzhou Innovation Institute Yuhang Hangzhou 310023China National Key Laboratory of Science and Technology on Aero-Engine Aero-Thermodynamics Beihang UniversityBeijing 100191China

In this paper,a kind of Wire Mesh Casing Treatment(WMCT)is proposed to improve the stable operating range of the *** contrast to the traditional circumferential groove,as for WMCT,a layer of wire mesh is laid on the surface of the circumferential *** studies were conducted on the low-speed axial flow compressor,including the groove width,axial location,and mesh *** optimum axial location for WMCT is related to its groove width.A higher wire mesh count results in a smaller compressor stall margin *** simulations were carried out to study the effect of WMCT on the flow structure of the *** wire mesh in the WMCT has a certain flow resistance,which restricts the flow into and out of the *** to the WMCT,the flow parameter in the tip region of the rotor is less sensitive to changes in the operating conditions of the *** WMCT causes the rotor tip blade loading to shift backward,inhibiting the formation of spill forward of the leakage flow,and thus improving the stability of the *** flow resistance on the groove surface is a new degree-of-freedom for the casing treatment designer.

关键词： Axial compressor Wire mesh casing treatment Tip clearance flow Stall margin Blade loading

A new 3-(3,4-methylenedioxyphenyl)-propane-1,2-diol glycoside from the roots of Cinnamomum camphora

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2011年第8期22卷 954-956页

作者： Rui Jiang Zhong Lin You Wu Wei Xiong Er Lei Xie Guo Ping Zhou dong ming zhang Jiangxi Provical Institute for Drug and Food Control Nanchang 330029 China Institute of Materia Medica Chinese Academy of Medical Sciences and Peking Union Medical College (Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine Ministry of Education) Beijing 100050 China

A new 3-（3,4-methylenedioxyphenyl）-propane-1,2-diol glycoside,named cinnamomdiol A（1）,together with two known compounds,3-（3,4-methylenedioxyphenyl）-propane-1,2-diol（2） and taxifolin（3）,was isolated from the roots of Cinnamomum *** structures were determined on the basis of spectroscopic *** 2 and 3 were isolated from the title plant for the first time.

关键词： Cinnamomum camphora 3-(3 4-Methylenedioxyphenyl)-propane-1 2-diol glycoside Cinnamomdiol A

Twisted Integration of Complex Oxide Magnetoelectric Heterostructures via Water‑Etching and Transfer Process

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2024年第1期16卷 360-369页

作者： Guannan Yang Guohua dong Butong zhang Xu Xu Yanan Zhao Zhongqiang Hu ming Liu State Key Laboratory for Manufacturing Systems Engineering Electronic Materials Research LaboratoryKey Laboratory of the Ministry of EducationEngineering Research Center of Spin Quantum Sensor ChipsUniversities of Shaanxi ProvinceSchool of Electronic Science and EngineeringXi’an Jiaotong UniversityXi’an 710049People’s Republic of China

Manipulating strain mode and degree that can be applied to epitaxial complex oxide thin films have been a cornerstone of strain *** recent years,lift-off and transfer technology of the epitaxial oxide thin films have been developed that enabled the integration of heterostructures without the limitation of material types and crystal ***,twisted integration would provide a more interesting strategy in artificial magnetoelectric heterostructures.A specific twist angle between the ferroelectric and ferromagnetic oxide layers corresponds to the distinct strain regulation modes in the magnetoelectric coupling process,which could provide some insight in to the physical *** this work,the La_(0.67)Sr_(0.33)MnO_(3)(001)/0.7Pb(Mg_(1/3)Nb_(2/3))O_(3)-0.3PbTiO_(3)(011)(LSMO/PMN-PT)heterostructures with *** *** angles were assembled via water-etching and transfer *** transferred LSMO films exhibit a fourfold magnetic anisotropy with easy axis along LSMO.A coexistence of uniaxial and fourfold magnetic anisotropy with LSMO[110]easy axis is observed for the 45°Sample by applying a 7.2 kV cm^(−1)electrical field,significantly different from a uniaxial anisotropy with LSMO[100]easy axis for the 0°*** fitting of the ferromagnetic resonance field reveals that the strain coupling generated by the 45°twist angle causes different lattice distortion of LSMO,thereby enhancing both the fourfold and uniaxial *** work confirms the twisting degrees of freedom for magnetoelectric coupling and opens opportunities for fabricating artificial magnetoelectric heterostructures.

关键词： Magnetoelectric heterostructures Twist angle Epitaxial lift-off Magnetic anisotropy Ferromagnetic resonance