检索结果-南通市图书馆

Rare Metals 2024年第2期43卷 624-634页

作者： xing-yuan zhang Mei-Na Lei Shan Tian Jian-Gan Wang State Key Laboratory of Solidification Processing Center for Nano Energy MaterialsSchool of Materials Science and EngineeringNorthwestern Polytechnical University and Shaanxi Joint Laboratory of Graphene(NPU)Xi’an710072China

High-energy-density Li-S batteries are subjected to serious sulfur deactivation and short cycle lifetime caused by undesirable polysulfide shuttle effect and frantic lithium dendrite *** this work,a controllable cage-confinement strategy to fabricate molybdenum carbide(MoC)nanoclusters as a high-efficient sulfiphilic and lithiophilic regulator to mitigate the formidable issues of Li-S batteries is *** sub-2 nm MoC nanoclusters not only guarantee robust chemisorption and fast electrocatalytic conversion of polysulfides to enhance the sulfur electrochemistry,but also homogenize Li^(+) flux to suppress the lithium dendrite *** a consequence,the MoC-modified separator endows the batteries with boosted reaction kinetics,promoted sulfur utilization,and improved cycling stability.A reversible capacity of 701 mAh·g^(−1) at a high rate of 5.0C and a small decay rate of 0.076%per cycle at 1.0C over 600 cycles are *** study offers a rational route for design and synthesis of bifunctional nanoclusers with both sulfiphilicity and lithiophilicity for high-performance Li-S batteries.

关键词： Li-S batteries Nanocluster Electrocatalyst Polysulfide shuttle Li dendrites

Black Hole Entropy with Modified Dispersion Relations

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2009年第8期52卷 261-263页

作者： WANG Fu-Jun GUI yuan-xing zhang Yu School of Physics and Optoelectronic Technology Dalian University of Technology Dalian 116024 China

There is much interest in resolving the quantum corrections to Bekenstein-Hawking entropy with a large length scale limit. The leading correction term ＆ given by the logarithm of black hole area with a model-dependent coefficient. Recently the research for quantum gravity implies the emergence of a modification of the energy-momentum dispersion relation （MDR）, which plays an important role in the modified black hole thermodynamics. In this paper, we investigate the quantum corrections to Bekenstein-Hawking entropy in four-dimensional Sehwarzschild black hole and Reissner-Nordstrom black hole respectively based on MDR.

关键词： black hole entropy dispersion relation

Determination of sulfite in water samples by flow injection analysis with fluorescence detection

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2010年第12期21卷 1457-1461页

作者： Li Qian Yin Dong xing yuan Min zhang State Key Laboratory of Marine Environmental Science Environmental Science Research Centre Xiamen University Xiamen 361005 China

A fast,sensitive,and reliable method for the determination of sulfite（SO3^2-） in fresh water and seawater samples was *** proposed method was based on the reaction of o-phthalaldehyde（OPA）-sulfite-NH_3 in alkaline solution,with flow injection analysis and fluorescence *** experimental parameters were investigated in pure water and seawater matrixes. The detection limits（S/N = 3） were 0.006μmol/L in pure water and 0.018μmol/L in seawater for SO3^2-.The method was successfully applied to analyze SO3^2- iin the samples of rain water and flue gas desulfurization seawater.

关键词： Sulfite Fluorophotometry FIA Flue gas desulfurization seawater Rainwater

Synthesis and fluorescence enhancement behavior of a novel fluorescent aqueous polyurethane emulsion DDAQ-TDI-PU

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2012年第7期23卷 855-858页

作者： Xian Hai Hu xing yuan zhang Jia Bing Dai CAS Key Laboratory of Soft Matter Chemistry Department of Polymer Science and EngineeringUniversity of Science and Technology of ChinaHefei 230026China School of Materials and Chemical Engineering Anhui Institute of Architecture and IndustryHefei 230022China

A novel fluorescent aqueous polyurethane emulsion DDAQ-TDI-PU was synthesized by blocking the anthraquinone moiety of 1,4-diamino-2,3-diphenoxyanthraquinone（DDAQ） into polyurethane chain using 2,4-tolylene diisocyanate（TDI）,poly（propylene glycol） and 2,2-dimethylol propionic *** chain structure of DDAQ-TDI-PU was confirmed by means of Fourier transform infrared spectroscopy and UV-vis *** to the UV-vis spectrum of DDAQ,DDAQ-TDI-PU showed a hypsochromic shift from the absorption maxima of 518,558,609 nm to 510,548,586 nm,*** was found that the fluorescence intensity of DDAQ-TDI-PU emulsion was enhanced greatly comparing with that of *** fluorescence of DDAQ-TDI-PU was very stable not only for the long term storage but also for the fluorescence quencher.

关键词： Polyurethane Aqueous emulsion 1,4-Diamino-2,3-diphenoxyanthraquinone Fluorescence enhancement

Synthesis and characterization of a novel waterborne stilbene-based polyurethane fluorescent brightener

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 997-1000页

作者： Xian Hai Hu xing yuan zhang Jia Bin Dai CAS Key Laboratory of Soft Matter Chemistry Department of Polymer Science and Engineering University of Science and Technology of China Hefei 230026 China School of Materials and Chemical Engineering Anhui Institute of Architecture and Industry Hefei 230022 China

A novel waterborne stilbene-based polyurethane fluorescent brightener dispersion WPU-VBL was synthesized by incorporating chemically disodium 4,4＇-bis[（4-anilino-6-hydroxyethylamino-1,3,5-triazin-2-yl）amino]stilbene-2,2＇-disulphonate（VBL） into the polyurethane chain using isophorone diisocyanate,poly（propylene glycol） and 2,2-dimethylol propionic *** structure of WPU-VBL was confirmed by means of Fourier transform infrared *** UV-vis absorption analysis showed a hypsochromic shift of 16 nm when VBL was blocked into polyurethane *** average molecular weight of 2.1×10~4, molecular weight distribution of 2.1 and average latex particle size of about 70 nm for WPU-VBL were determined based on the analysis of gel permeation chromatography and laser particle size *** was found that the fluorescence intensity of WPU-VBL was prominently enhanced because of the micro-circumstance of VBL and the fluorescence of WPU-VBL was very stable.

关键词： Waterborne polyurethane Fluorescent brightener VBL Fluorescence

Synthesis and characterization of a novel hydroxypolyether blocked polydimethylsiloxane PEO-b-PDMS-b-PEO

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2008年第10期19卷 1209-1211页

作者： Wei Hu Li xing yuan zhang Jia Bing Dai CAS Key Laboratory of Soft Matter Chemistry Department of Polymer Science and Engineering University of Science and Technology of China Hefei 230026 China

A novel hydroxypolyether blocked polydimethylsiloxane, poly（ethylene oxide） propyl-b-polydimethylsiloxane-b-propyl poly（ethylene oxide）（PEO-b-PDMS-b-PEO） was synthesized by simple hydrosilation reaction of poly（ethylene glycol） monoallyl ether with α,ω-dihydrogen terminated PDMS （HPDMS）. Fourier transform infrared spectroscopy （FTIR） and IH NMR were used to identify the structure of PEO-b-PDMS-b-PEO and intermediate product HPDMS. Based on the effect investigations of temperature, reactant molar ratio, catalyst and time on the hydrosilation, it was found that the conversion of Si-H bond to SiC bond increased with the increase of catalyst and time, and the reaction completed when the content of catalyst was 22μg/g and the time was 5 h, respectively. Urethane reaction of OH and NCO group confirms that PEO-b-PDMS-b-PEO is more reactive toward to diisocyanate than α,ω-dihydroxylbutyl terminated PDMS.

关键词： Synthesis Polydimethylsiloxane Hydrosilation reaction Reactivity

Synthesis and characterization of fluorinated PEO-b-PDMS-b-fluorinated PEO by free radical addition

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2009年第9期20卷 1127-1130页

Fluorinated poly（ethylene oxide） propyl-b-polydimethylsiloxane-b-propyl fluorinated poly（ethylene oxide）（FPEO-b-PDMS-b- FPEO） was synthesized by a free radical addition of carbon-hydrogen of polyether segments of poly（ethylene oxide） propyl-b- polydimethylsiloxane-b-propyl poty（ethylene oxide）（PEO-b-PDMS-b-PEO） to hexafluoropropylene （HFP） using tert-butyl peroxypivalate as an initiator. In order to reduce the possibility of side reaction, the protection and deprotection via silylation were used for the end-hydroxyls in PEO-b-PDMS-b-PEO chain. The structure of Intermediates and FPEO-b-PDMS-b-FPEO was confirmed by means of Fourier transform infrared and 1H NMR spectroscopy. The effects of amount of initiator, reaction temperature and time on free radical addition were investigated in detail. 2009 xing yuan zhang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

关键词： Fluorinated Hexafluoropropylene Polydimethylsiloxane Free radical addition Silylation

Grafting of Hexafluoropropylene onto Polytetramethylene Glycol by Radical Reaction

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2005年第12期16卷 1600-1602页

作者： Zhen GE xing yuan zhang Jia Bing DAI Xiao Le TAO Department of Polymer Science and Engineering University of Science and Technology of China Hefei 230026 Hangzhou Zhijiang Silicone Chemicals Co. Ltd. Hangzhou 311203

A well-defined modification of polytetramethylene glycol （PTMG） was realized by radical grafting with hexafluoropropylene （HFP）. The structure of grafted product was confirmed by means of IR, ^1H NMR and ^13C NMR. The effects of the amount of initiator, reaction time and temperature on the grafting HFP onto PTMG were investigated.

关键词： Radical grafting polytetramethylene glycol fluoropolymers

Synthesis of a Novel UV Curable Aqueous Dispersion Polyurethane PDHA-PEDA-PU and the Properties of Cured Film

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2006年第3期17卷 369-372页

作者： Chen Yan BAI xing yuan zhang Jia Bing DAI Wei Hu LI Department of Polymer Science and Engineering University of Science and Technology of China Hefei 230026

A novel ultraviolet （UV） curable aqueous dispersion polyurethane PDHA-PEDA-PU was synthesized based on isophorone diisocyanate （IPDI）, polyester dihydric alcohol （PDHA）, dimethylol propionic acid （DMPA）, pentaerythritol diacrylate （PEDA）, 2-hydroxyethyl acrylate （HEA） and triethylamine （TEA）. Acrylate groups were incorporated in the side and end of PDHA-PEDA-PU chain. The C=C content in the chain can be controlled easily through the change of IPDI/PDHA/PEDA ratio. Fourier transform infrared spectroscopy （FTIR） was used to identify the structure of prepolymer, aqueous dispersion and cured polyurethane. The curing rule of the polyurethane for different C=C content has been investigated depending on the change of C=C content during the curing process. The hardness, thermal stability and scrub resistance to MEK of UV cured PDHA-PEDA-PU were also discussed for the samples with different C=C content.

关键词： UV curable aqueous dispersion polyurethane

Monte Carlo Study on Spontaneous Recoil of Confined DNA Chain

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Physics 2008年第3期21卷 281-285页

作者： Yong-jun Xie Hong-tao Yu Hai-yang Yang Yao Wang xing-yuan zhang Qin-wei Shi Department of Polymer Science and Engineering University of Science and Technology of ChinaHefei 230026 China Hefei National Laboratory for Physical Sciences at Microscales University of Science and Tech-nology of China Hefei 230025 China

A part of a long DNA chain was driven into a confined environment by an electric field, while the rest remains in the higher-entropy region. Upon removal of the field, the chain recoils to the higher-entropy region spontaneously. This dynamical process was investigated by Monte Carlo simulations. The simulation reproduces the experimentally-observed phenomenon that the recoil of the DNA chain is initially slow and gradually increases in speed due to the presence of the confinement-entropic force. The results show that with increasing the dimension or decreasing the spacing of the nanopillars the recoil velocity of the DNA chain will increase. Further analysis suggests that the characteristic entropy per monomer in the confinement is proportional to the area fraction of the free part in the confinement.

关键词： DNA chain Spontaneous recoil Monte Carlo simulation Effective entropy