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Carboxyl graphene oxide solution saturable absorber for femtosecond mode-locked erbium-doped fiber laser

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Chinese Physics B 2018年第11期27卷 517-521页

作者： Rui-dong Lv Lu li yong-gang Wang Zhen-dong Chen Si-cong liu Xi Wang Jiang wang yong-fang li School of Physics and Information Technology Shaanxi Normal University School of Science Xi'an Institute of Posts and Telecommunications State Key Laboratory of Transient Optics and Photonics Xi'an Institute of Optics and Precision MechanicsChinese Academy of Sciences

The carboxyl-functionalized graphene oxide(GO-COOH)is a kind of unique two-dimensional(2 D)material and possesses excellent nonlinear saturable absorption property and high *** this paper,we prepare saturable absorber(SA)device by depositing GO-COOH nanosheets aqueous solution on a D-shaped *** modulation depth(MD)and saturable intensity of the SA are measured to be 9.6%and 19 MW/cm^(2),*** inserting the SA into the erbium-doped fiber(EDF)laser,a passively mode-locked EDF laser has been achieved with the spectrum center wavelength of 1562.76 *** pulse duration,repetition rate,and the signal-to-noise ratio(SNR)are 500 fs,14.79 MHz,and 80 dB,*** maximum average output power is measured to be 3.85 *** results indicate that the GO-COOH nanosheets SA can be used as a promising mode locker for the generation of ultrashort pulses.

关键词： fiber lasers mode-locked pulse nonlinear optical materials carboxyl graphene oxide

Orthogonal Solubility in Fully Conjugated Donor-Acceptor Block Copolymers： Compatibilizers for Polymer/Fullerene Bulk-Heterojunction Solar Cells

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Chinese Journal of Polymer Science 2017年第2期35卷 207-218页

作者： Shi-fan Wang Ya-nan liu Jie Yang 陶友田 Yan Guo Xu-dong Cao 张志国 yong-fang li 黄维 Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM) Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM)Nanjing Tech University (Nanjing Tech) Institute of Chemistry Chinese Academy of Sciences Department of Biomedical Engineering College of Engineering and Applied Sciences

Donor-acceptor （D-A） type fully conjugated block copolymer systems have been rarely reported due to the challenges in synthetic approaches to prepare well-defined low-polydispersity products. In this work, fully conjugated block copolymers are synthesized in a one-pot reaction through Stille coupling polycondensation, by utilizing the end-functional polymer copolymerization method. End-functional P3HT are copolymerized with AA （2,7-dihromo-9-（heptadecan-9-yl）-9H- carbazole） and BB （4,7-bis（5-（trimethylstannyl）thiophen-2-yl）benzo[c][1,2,5]thiadiazole, TBT） type monomers, respectively. The orthogonal solubility between the very soluble P3HT donor and the insoluble PCDTBT acceptor block improves the purity of block copolymers as well as distinct nano-scale phase-separation compared with other reports on miscibility of donor and acceptor polymer block. Further purification via preparative GPC is carried out to remove the excess of unreacted P3HT and free PCDTBT as well as to achieve low polydispersity of block copolymers. The chemical structure of the P3HT- b-PCDTBT block copolymers are verified via IH-NMR, and further confirmed by FTIR spectra. The block copolymer shows broad absorption and moderate optical band gap of 1.8 eV. Furthermore, the fully conjugated block copolymer films exhibit significant fine structures, much smoother film morphology compared to P3HT/PCDTBT polymer blends. By adding a small amount of block copolymer P3HT-b-PCDTBT as a compatibilizer into the bulk-heterojunction of P3HT：PC61BM blends, polymer solar ceils with an 8% increase of short circuit current （Jse） and 10% increase of power conversion efficiency （PCE） are achieved owing to the improvement of the active-layer film morphology. To the best of our knowledge, this is the first report on donor-acceptor type fully conjugated block copolymer as an effective ternary additive in polymer： fullerene bulk heterojunction solar cells.

关键词： Block copolymers Donor Acceptor Bulk heterojunction solar cells Compatibilizer

Sequence-Controlled Synthesis of Alternating Poly(ester amide)s using Water as Control Agent in One-Pot

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Chinese Journal of Polymer Science 2024年第8期42卷 1015-1020页

作者： Tao liu fang-fang Niu Kan Cheng Yu-Min Xia Bo-Mou Ma Xue-li Wang Jian-yong Yu yong He State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and EngineeringDonghua UniversityShanghai 201620China Innovation Center for Textile Science and Technology Donghua UniversityShanghai 201620China

Poly(ester amide)s(PEAs)attract much attention as a new kind of biodegradable ***,the synthesis of PEAs with sequence-regulated chain structures is still complicated due to the multistep polymerization,high monomer purity,as well as the usage of organic solvents,which greatly inhibits its development and ***,a one-pot strategy without solvent was developed to synthesize the alternating PEA fromα,ω-amino alcohol and dicarboxylic acid by sequential polycondensation,where water was used as the controlling agent for amidation and ***,the amidation and esterification were controlled to proceed in turn by adding or removing water,realizing the one-pot preparation of alternating *** resultant PEA is characterized by^1H-and^(13)C-NMR,and its chain structure is confirmed to be highly quasi-alternating similar to alternating PEAs prepared by classical methods The evaluations from DSC and DMA demonstrate that the properties of quasi-alternating PEA(T_(m)=102℃,ΔH_(m)=30J·g^(-1))are far superior to those of random PEA(T_(m)=72℃,ΔH_(m)<1 J·g^(-1)).

关键词： Biodegradable macromolecules Polymer architectures Sequence-controlled synthesis One-pot polymerization

PREPARATION AND CHARACTERIZATION OF A NEW HEXAHYDROPYRROliZINE DERIVATIVE OF FULLERENE

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Chinese Chemical Letters 1995年第3期6卷 201-204页

作者： Hone Xian HAN Yu liang li yong fang li Ming yong HAN Zi WU Yi Ming MO Fend lian BAI Dao Ben ZHU Institute of Chemistry Chinese Academy of SciencesBeijing 100080

C60 undergoes 1 .3-dipolar cycloaddition reaction with the 1.3-dipole derived from heating 4-hydroxy-L-proline and paraformaldehyde to form a monoadduct in yield of 29.3%.

关键词： 1?

The Electrochemical Behavior of PPV/PEO Blend

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Chinese Chemical Letters 1998年第3期9卷 305-306页

作者： Chun He YANG Jun Rong ZHENG yong fang li(Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080_ Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China

The electrochemical behavior of PPV/PEO blend with different dopants was investigated by cyclic voltammetry. The p-doping process is electrochemically quasi-reversible while the n-doping is irreversible. The band gap ... 详细信息

关键词： conjugated polymer electrochemical behavior electrochemical doping

A New Method for Solving Nonlinear Partial Differential Equations Based on liquid Time-Constant Networks

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Journal of Systems Science & Complexity 2024年第2期37卷 480-493页

作者： SUN Jiuyun DONG Huanhe fang yong College of Mathematics and Systems Science Shandong University of Science and TechnologyQingdao 266590China

In this paper,physics-informed liquid networks(PILNs)are proposed based on liquid time-constant networks(LTC)for solving nonlinear partial differential equations(PDEs).In this approach,the network state is controlled via ordinary differential equations(ODEs).The significant advantage is that neurons controlled by ODEs are more expressive compared to simple activation *** addition,the PILNs use difference schemes instead of automatic differentiation to construct the residuals of PDEs,which avoid information loss in the neighborhood of sampling *** this method draws on both the traveling wave method and physics-informed neural networks(PINNs),it has a better physical ***,the KdV equation and the nonlinear Schr¨odinger equation are solved to test the generalization ability of the *** the best of the authors’knowledge,this is the first deep learning method that uses ODEs to simulate the numerical solutions of PDEs.

关键词： Nonlinear partial differential equations numerical solutions physics-informed liquid networks physics-informed neural networks

Improving flangeability of multiphase steel by increasing microstructural homogeneity

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Journal of Iron and Steel Research International 2024年第7期31卷 1736-1745页

作者： Xiao-yu Yang yong-gang Yang Xing fang Han-long Zhang Zhen-li Mi Beijing Advanced Innovation Center for Materials Genome Engineering Institute of Engineering TechnologyUniversity of Science and Technology BeijingBeijing 100083China Shanghai Baosteel Group Corp.Technology Center Shanghai 201900China

Multiphase microstructure significantly increases the strength,usually at the expense of flangeability because of lacking microstructure *** further improve the strength-flangeability of multiphase steel,the microstructural homogeneity was advanced by adjusting the hard martensite/austenite(M/A)*** strength-flangeability was measured via uniaxial tensile tests and hole expansion *** microstructures were characterized using a scanning electron microscope equipped with an electron backscatter diffraction detector and a transmission electron *** tests were supplementally used to quantitatively reveal the microstructural homogeneity of the *** show that the adjusted multiphase steel achieves an excellent ultimate tensile strength(~800 MPa)and flangeability(~135%hole expansion ratio).A promising homogeneous multiphase microstructure was obtained by controlling undercooled austenite transformed at about 600℃.This microstructure consists of soft polygonal ferrite,blocky bainitic ferrite,and hard M/A *** volume fraction of M/A islands is around 5%,and the average size is less than l *** nanoindentation analysis indicated that the participation of M/A islands impressively influenced the microstructural *** strain partition and better mechanical compatibility were present in the adjusted multiphase steel since the plasticity initiation started late,which resulted in a positive ***,avoiding M/A islands distributed in the chain along the rolling direction on the matrix hindered the possibility of voids coalescing into cracks and stabilized the flanging performance.

关键词： Multiphase steel Flangeability Martensite/austenite island-Microstructural homogeneity-Microstructure Compact strip production process

THE SYNTHESIS AND CHARACTERISATION OFASYMMETRIC HYDROMETHYL BEDT-TTF

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Chinese Chemical Letters 1996年第6期7卷 573-576页

作者： Wei QIN Bin ZHANG You An YAO yong fang li Dao Ben ZHU(Institute of Chemistry, Chinese Academy of Science, Beijing 100080) Institute of Chemistry Chinese Academy of Science Beijing 100080

A new bisethyldithionetetrathiafulvalene (ET) derivative was synthesised. The cyclic voltammogram comparison of asymmetric hydromethyl bisethyldithionetetrathiafulvalene (HMET) and ET was made. The single crystal of charge transfer complex HMETI(X) was obtained and characterised. The conductivity of the single crystal was measured between room temperature and liquid nitrogen temperature. This single crystal is a semiconductor in the liquid nitrogen temperature range.

关键词： THE SYNTHESIS AND CHARACTERISATION OFASYMMETRIC HYDROMETHYL BEDT-TTF

Highly efficient pH-universal hydrogen evolution reaction catalyzed by rapidly reconstructed bimetallic cobalt-molybdenum alloy cuboids arrays

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Nano Research 2024年第8期17卷 6977-6983页

作者： Daolian liu Zihao Wang Yan Zhang Haiqing Zhou yong Zhang Dongyang li fang Yu Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education Key Laboratory for Matter Microstructure and Function of Hunan ProvinceDepartment of Physics and Synergetic Innovation Center for Quantum Effects and ApplicationsHunan Normal UniversityChangsha 410081China State Key Laboratory of Marine Resource Utilization in South China Sea and Department of Materials Science and EngineeringHainan UniversityHaikou 570228China Institute of Interdisciplinary Studies Hunan Normal UniversityChangsha 410081China

Given the inherent potential of seawater,industrial wastewater,and residential water as inherent feedstocks for hydrogen production through water electrolysis,there is a critical demand for the exploration of robust and stable hydrogen-evolving catalysts that can operate effectively across a diverse range of pH ***,the pursuit of hydrogen-evolving electrocatalysts that demonstrate both good stability and high efficiency over a wide pH range remains a formidable *** we report the rational design and synthesis of an outstanding nanoporous hybrid electrocatalyst consisting of intermetallic cobalt-molybdenum alloy particles anchoring on MoO2 cuboid arrays,which demands very low overpotentials of 72,123 and 134 mV to deliver a current density of−100 mA·cm^(−2)for hydrogen evolution reaction under alkaline,neutral and acidic conditions,*** catalytic activities are superior to most non-precious-metal-based catalysts documented in the literatures,and are even comparable to noble metal *** particular,this alloy electrocatalyst exhibits excellent stability at 50 or 300 mA·cm^(−2)without obvious activity degradation,which is further supported by the undetectable changes in the surface chemical valence states on the basis of in-situ X-ray photoelectron spectroscopic *** study provides an innovative strategy for the design and synthesis of effective non-noble intermetallic catalysts for pH-universal hydrogen evolution over a wide pH range.

关键词： electrocatalyst hydrogen evolution reaction pH-universal non-noble water splitting