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MORPHOLOGICAL TRANSITION BETWEEN VESICLES AND TUBULES FOR A GLYCOPOLYMER-CONTAINING AMPHIPHIliC DIBLOCK COPOLYMER IN AQUEOUS SOLUTIONS

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Chinese Journal of Polymer Science 2001年第3期19卷 297-301页

作者： Zi-chen li Yue Shen Yu-zeng liang fu-mian li department of Polymer Science & Engineering College of chemistry peking university beijing 100871, china 北京大学北京

The morphological transition of molecular assemblies in aqueous solutions for a new amphiphilic diblock copolymer induced by changing the initial solvent conditions was studied by transmission electron microscopy (TEM). The copolymer was polystyrene(77)-b-poly[2-(beta -D-glucopyranosyloxy)ethyl acrylate (6)] (PSt(77)-b-PGEA(6)) and the solvent was a mixture of DMF and THF. PSt(77)-b-PGEA(6) yields vesicles and tubules when it is initially dissolved in THF and DMF respectively. The morphological transition between vesicles and tubules can be achieved by simply varying the amounts of THF and DMF, or changing the temperature at which the aggregates were prepared.

关键词： block copolymer amphiphile glycopolymer self-assembly tubule vesicle

SYNTHESIS　AND　VESICLES　OF　A　DOUBLE-CHAIN　GLYCOliPID

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Chinese Chemical Letters 1996年第5期7卷 401-402页

作者： Zi Chen li Wei HE fu mian li (department of chemistry peking university Beijng 100871) department of chemistry Peking University Beijing 100871

Abstract: A double-chain glycolipid, dioctadecyl-2-glucopyronosylthio-succinate(1) was *** glycolipid itself formed stable vesicles. It could also be incorporated into the lipid bilayer membrane to form Stable dried l...

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SURFACE　MODIFICATION　OF　PHOSPHOliPID　liPOSOMES　BY　INCORPORATION　OF　GLYCOliPID

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Chinese Chemical Letters 1995年第11期6卷 947-950页

作者： Zi Chen li Wei HE fu mian li(department of chemistry, peking Univerisity, beijing 100871) beijing Univ Dept Chem Beijing 100871 Peoples R China

Two single-chain glycolipids, octadecyl-β-D-glucopyranoside(1) and 2-octadecanamido-2-deoxy-D-glucopyranose(2) were synthesized and their dispersing properties in water were studied. Incorporation of 1 into the phospholipid liposomes could inhibit the aggregation of liposomes and improve the molecular packing in the bilayer membranes.

关键词： SURFACE GLYCOliPID INCORPORATION liPOSOMES MODIFICATION OF PHOSPHOliPID BY

Nanostructured Lead Sulfide Containing Nanoholes Templated by Lyotropic Hexagonal liquid Crystals

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Chinese Chemical Letters 2000年第5期11卷 467-470页

作者： Yan li Qing Min ZHANG fu Zhi HUANG Zhen Nan GU (department of Material chemistry, peking university, beijing 100871) department of Material chemistry Peking University

The hexagonal liquid crystal mediated synthesis of nanostructured PbS was studied. Thioacetamide and lead acetate were used as the sulfide and lead source, respectively. It was found that the nanohole structure of PdS... 详细信息

关键词： hexagonal liquid crystal nanomaterial lead sulfide

Synthesis of Cholesterol Derivative with Amino Acid as Hydrophilic Group and the Vesicles Prepared Therefrom

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Chinese Chemical Letters 1999年第12期10卷 0-0,0-0页

作者： Zi Chen li Wei JIN fu mian li(College of chemistry, peking university, beijing 100871)

Three single chain amphiphilic cholesterol derivatives with amino acid as hydrophilicgroups, Ⅰ,Ⅱ and Ⅲ, were synthesized. When they were hydrated in water, they can all formlamellae structures as evidenced by DSC measurement. The lamellae states of Ⅱ and Ⅲ can beconverted to vesicles upon ultrasonication of the diluted aqueous solutions. The vesicles showedvery slow release rate of the encapsulated water-soluble dyes, indicating that they are stable andbelong to the least permeable vesicles.

关键词： Vesicles amphiphiles amino acid cholesterol.

Sedimentary Environment and Mineralization of the Black Shale Polymetallic Layer in the Early Cambrian,SW china:Constraints from in situ LA-ICP-MS Analysis of Pyrite

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Acta Geologica Sinica(English Edition) 2024年第2期98卷 416-429页

作者： YANG Zhen fu Yong li Chao CAI Xi GUO Chuan College of Eco-Environmental Engineering Guizhou Minzu UniversityGuiyang 550025China College of Resources and Environmental Engineering Guizhou UniversityGuiyang 550025China Key Laboratory of Karst Georesources and the Environment Ministry of EducationGuizhou UniversityGuiyang 500025China National Research Center for Geoanalysis Chinese Academy of Geological SciencesBeijing 100037China

A polymetallic layer is usually developed at the bottom of the early Cambrian black shale in Guizhou *** mineral that makes up the polymetallic layer is related to the sedimentary *** analyze the differentiation mechanism between polymetallic deposits(Ni-Mo and V),the Zhijin Gezhongwu profile located in the outer shelf and the Sansui Haishan V deposit located in the lower slope are selected to study the in situ sulfur isotopes and trace elements of *** results show that δ^(34)S values of pyrite vary widely from−7.8‰to 28‰in the Gezhongwu profile,while the δ^(34)S values are relatively uniform(from 27.8‰to 38.4‰)in the Haishan *** isotopic S composition is consistent with the transition that occurs in the sedimentary phase from the shelf to the deep sea on the transgressive Yangtze platform;this indicates that the δ^(34)SO_(4)^(2−)values in seawater must be differently distributed in depositional *** sulfur in the Ni-Mo layer is produced after the mixing of seawater and hydrothermal fluid,while the V layer mainly originates from ***,the Ni-Mo and V deposits have been differentiated primarily on the basis of the combined effect of continental weathering and hydrothermal fluid.

关键词： sedimentary environment black shale polymetallic layer pyrite early Cambrian

Machine learning for fault diagnosis of high-speed train traction systems: A review

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Frontiers of Engineering Management 2024年第1期11卷 62-78页

作者： Huan WANG Yan-fu li Jianliang REN department of Industrial Engineering Tsinghua UniversityBeijing 100084China Zhibo Lucchini Railway Equipment Co. Ltd.Taiyuan 030032China

High-speed trains(HSTs)have the advantages of comfort,efficiency,and convenience and have gradually become the mainstream means of *** the operating scale of HSTs continues to increase,ensuring their safety and reliability has become more *** the core component of HST,the reliability of the traction system has a substantially influence on the *** the long-term operation of HSTs,the core components of the traction system will inevitably experience different degrees of performance degradation and cause various failures,thus threatening the running safety of the ***,performing fault monitoring and diagnosis on the traction system of the HST is *** recent years,machine learning has been widely used in various pattern recognition tasks and has demonstrated an excellent performance in traction system fault *** learning has made considerably advancements in traction system fault diagnosis;however,a comprehensive systematic review is still lacking in this *** paper primarily aims to review the research and application of machine learning in the field of traction system fault diagnosis and assumes the future development ***,the structure and function of the HST traction system are briefly ***,the research and application of machine learning in traction system fault diagnosis are comprehensively and systematically ***,the challenges for accurate fault diagnosis under actual operating conditions are revealed,and the future research trends of machine learning in traction systems are discussed.

关键词： high-speed train traction systems machine learning fault diagnosis

How interfacial electron-donating defects influence the structure and charge of gold nanoparticles on TiO_(2)support

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Nano Research 2024年第7期17卷 5965-5974页

作者： Guang-Jie Xia Yu fu Wei Cao Jun li Yang-Gang Wang department of chemistry and Guangdong Provincial Key Laboratory of Catalysis Southern University of Science and TechnologyShenzhen 518055China School of Physical Sciences Great Bay UniversityDongguan 523000China department of chemistry Tsinghua UniversityBeijing 100084China

The reduction degree of TiO_(2)support is critical to the performances of metal *** many previous theoretical calculations,only the bridge oxygen vacancy(Ov)was considered as the electron-donating defect on reduced rutile TiO_(2)(r-TiO_(2−x))***,titanium adatoms(Tiad.),oxidized titanium islands(***),and acid hydroxyls(ObrH)also exist at the metal/support *** conducting density functional theory(DFT)calculations and ab initio molecular dynamics(AIMD)simulations,we compared r-TiO_(2−x)surfaces with Ov,Tiad.,***,and ObrH sites loaded with Au nanoparticles(NPs).The results showed the Au NPs were oxygen-phobic but titanium-philic,resulting in wetting of Ov and *** short contact with *** and *** Bader charges of Au NPs(QM)showed a good linear relationship with the ideal number of donating electrons(Ne)from the defective sites(QM=−KeNe+QM,S),demonstrating the intrinsic electron allocation at the *** Ov,Tiad.,and *** exhibited similar slopes(Ke),relatively steeper than that of *** means in the scope of Au NP charge state,the *** *** have a close electron-donating ability with Ov,but the ObrH donates relatively fewer *** linear relationship can be extended approximately to other *** higher the metal work function,the steeper the Ke for easier electron donation from defective *** stronger the metal oxygen affinity,the more positive the intercept(QM,S).That explains the easy generation of metallic or negative Pt and Au NPs on r-TiO_(2−x),but hard for Cu and Zn in *** provides theoretical guidance for regulating the charge of metal NPs over TiO_(2−x)supports.

关键词： metal-support interaction titanium oxide oxygen vacancy surface hydroxyl titanium adatom

VSAN:A new visualization method for super-large-scale academic networks

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Frontiers of Computer Science 2024年第1期18卷 119-137页

作者： Qi li Xingli WANG Luoyi fu Xinde CAO Xinbing WANG Jing ZHANG Chenghu ZHOU department of Electronic Engineering Shanghai Jiao Tong UniversityShanghai 200240China department of Computer Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China School of Environmental Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China School of Oceanography Shanghai Jiao Tong UniversityShanghai 200240China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China

As a carrier of knowledge,papers have been a popular choice since ancient times for documenting everything from major historical events to breakthroughs in science and *** the booming development of science and technology,the number of papers has been growing *** like the fact that Internet of Things(IoT)allows the world to be connected in a flatter way,how will the network formed by massive academic papers look like?Most existing visualization methods can only handle up to hundreds of thousands of node size,which is much smaller than that of academic networks which are usually composed of millions or even more *** this paper,we are thus motivated to break this scale limit and design a new visualization method particularly for super-large-scale academic networks(VSAN).Nodes can represent papers or authors while the edges means the relation(e.g.,citation,coauthorship)between *** order to comprehensively improve the visualization effect,three levels of optimization are taken into account in the whole design of VSAN in a progressive manner,i.e.,bearing scale,loading speed,and effect of layout *** main contributions are two folded:(1)We design an equivalent segmentation layout method that goes beyond the limit encountered by state-of-the-arts,thus ensuring the possibility of visually revealing the correlations of larger-scale academic entities.(2)We further propose a hierarchical slice loading approach that enables users to observe the visualized graphs of the academic network at both macroscopic and microscopic levels,with the ability to quickly zoom between different *** addition,we propose a“jumping between nebula graphs”method that connects the static pages of many academic graphs and helps users to form a more systematic and comprehensive understanding of various academic *** our methods to three academic paper citation datasets in the AceMap database confirms the visualization scalability of VSAN in t

关键词： academic networks large graph visualization graph layout graph loading