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Rare Metals 2024年第6期43卷 2859-2868页

作者： huan-shi lan Yi-Da Yang Qing-Di Sun Hao Zhang Ying Zhang Qian He Ran Chen Guo-Yi Bai Xiao-Hui He Hong-Bing Ji School of Chemistry and Chemical Engineering Guangxi UniversityNanning 530004China Key Laboratory of Bioinorganicand Synthetic Chemistry of Ministry of Education Fine Chemical Industry Research InstituteSchool of ChemistryIGCMESun Yat-sen UniversityGuangzhou510275China UBFC CNRSENSMMFEMTO-ST Institute25030 Besancon CEDEXFrance College of Chemistry and Materials Science Hebei UniversityBaoding 071002China State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology Institute of Green Petroleum Processing and Light Hydrocarbon ConversionCollege of Chemical EngineeringZhejiang University of TechnologyHangzhou 310014China

Selective hydrogenation of C=C and C=O bonds in cinnamaldehyde(CAL)to produce desired products is a challenging task due to the complex conjugate system of the two unsaturated functional *** this study,a simple ball milling method is presented for synthesizing Pt-based single-atom alloy catalysts(SAAs)that can function as a control switch for the selective hydrogenation of CAL into highly valuable products.

关键词： alloy hydrogenation conjugate

Multiple Tin Compounds Modified Carbon Fibers to Construct Heterogeneous Interfaces for Corrosion Prevention and Electromagnetic Wave Absorption

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Nano-Micro Letters 2025年第1期17卷 507-527页

作者： Zhiqiang Guo Di lan Zirui Jia Zhenguo Gao Xuetao shi Mukun He Hua Guo Guanglei Wu Pengfei Yin College of Science Sichuan Agricultural UniversityYa’an 625014People’s Republic of China School of Materials Science and Engineering Hubei University of Automotive TechnologyShiyan 442002People’s Republic of China Institute of Materials for Energy and Environment State Key Laboratory of Bio‑Fibers and Eco‑TextilesCollege of Materials Science and EngineeringQingdao UniversityQingdao 266071People’s Republic of China Shaanxi Key Laboratory of Macromolecular Science and Technology School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’anShaanxi 710072People’s Republic of China

Currently,the demand for electromagnetic wave(EMW)absorbing materials with specific functions and capable of withstanding harsh environments is becoming increasingly ***-component interface engineering is considered an effective means to achieve high-efficiency EMW ***,interface modulation engineering has not been fully discussed and has great potential in the field of EMW *** this study,multi-component tin compound fiber composites based on carbon fiber(CF)substrate were prepared by electrospinning,hydrothermal synthesis,and high-temperature thermal *** utilizing the different properties of different substances,rich heterogeneous interfaces are *** effectively promotes charge transfer and enhances interfacial polarization and conduction *** prepared SnS/SnS_(2)/SnO_(2)/CF composites with abundant heterogeneous interfaces have and exhibit excellent EMW absorption properties at a loading of 50 wt%in epoxy *** minimum reflection loss(RL)is−46.74 dB and the maximum effective absorption bandwidth is 5.28 ***,SnS/SnS_(2)/SnO_(2)/CF epoxy composite coatings exhibited long-term corrosion resistance on Q235 steel ***,this study provides an effective strategy for the design of high-efficiency EMW absorbing materials in complex and harsh environments.

关键词： Electrostatic spinning Component regulation Heterogeneous interfaces Electromagnetic wave absorption Corrosion protection

Linear Viscoelasticity of ABA-type Vitrimer Based on Dioxaborolane Metathesis

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Chinese Journal of Polymer Science 2024年第10期42卷 1495-1504,I0010页

作者： shi-Long Wu huan-huan Yang Quan Chen State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of ScienceChangchun130022China University of Science and Technology of China Hefei230026China

In this study,we synthesized a series of ABA-type vitrimers by crosslinking the short A moieties of precursors with a bifunctional crosslinker and evaporating the small molecular *** vitrimer samples thus prepared exhibit linear viscoelasticity dependent on the length of A moiety as well as the content of the *** the average number of A monomers per end moiety m=1.1,the crosslinker can only extend the chain but not crosslink the *** m becomes 2.8 or higher,introducing a crosslinker first leads to the gelation,whereas excess in crosslinker molecules leads opening of the crosslinking sites and accordingly reentry into the sol ***,a further increase in the length of the A moieties increases the relaxation time much weaker than the exponential increase seen for the physically crosslinked ABAtype *** attribute this difference to the distinct relaxation mechanisms:the relaxation of the vitrimer samples is based on relatively independent exchange reactions,which contrasts with the ABA-type ionomers that relax through the collective hopping of connected ionic groups from one ion aggregate to another.

关键词： Polymer rheology Linear viscoelasticity ABA-type vitrimer Relaxation mechanism Kinetics and thermodynamics

Waveform design for higher-level 3D constellation mappings and its construction based on regular tetrahedron cells

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Science China(Information Sciences) 2015年第8期58卷 13-24页

作者： shi PengFei huan Hao TAO Ran School of Information and Electronics Beijing Institute of Technology Key Lab for Spacecraft TT&C and Communication under the Ministry of Education

In this paper, we propose a generalized method of high-level three dimensional(3D) signal constellation mapping based on the most basic 3D structure: regular tetrahedron cells. First, we redefined the waveform design, the normalized frequency and phase modulation for the geometric construction of tetrahedron ***, the new topology of tetrahedron cells based on the traditional lattice 3D constellation were ***, we focused on the two essential types, 8-ary and 16-ary based on tetrahedron cells on behalf of the odd and even carry bits, respectively. The available range and closed forms of the symbol error probability(SEP)were derived to increase the effectiveness and safety of wireless communication systems. Normalized minimum Euclidean distance and average number of neighbors were utilized to measure the performance against Gaussian noise. Simulation results showed that the proposed 8-ary and 16-ary 3D constellation mapping obtained 0.25 and 0.5 d B gain at the SEP of 10-6and 10-4, respectively, over traditional 3D lattice structure in additive white Gaussian noise(AWGN) channel.

关键词： waveform design 3D constellation mapping regular tetrahedron cells OFDM systems wireless communication

Anisotropic flow in high baryon density region

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Nuclear Science and Techniques 2022年第2期33卷 79-86页

作者： Shao-Wei lan Shu-Su shi Key Laboratory of Quark and Lepton Physics(MOE)and Institute of Particle Physics Central China Normal UniversityWuhan 430079China

Collective flow is a powerful tool used to analyze the properties of a medium created during high-energy nuclear ***,we report a systematic study of the first two Fourier coefficients v_(1)and v_(2)of the proton andπ^(+)from Au+Au collisions in the energy range√sNN=2.11-4.9 GeV within the framework of a hadronic transport model(UrQMD).Recent results from the STAR experiment were used to test the model calculations.A meanfield mode with strong repulsive interaction is needed to reproduce the 10-40%data at 3 *** implies that hadronic interactions play an important role in the collective flow development in the high baryon density *** mean values of the freeze-out time for protons andπ^(+)are shifted earlier owing to the additional repulsive *** predict the energy dependence of the mean values of the transverse momentum,v_(1),and v_(2)for both protons andπ^(+)from the Au+Au collisions.

关键词： Heavy-ion collisions QCD phase diagram UrQMD Collective flow Mean-field potential

Spray and mixing characteristics of liquid jet in a tubular gas-liquid atomization mixer

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Chinese Journal of Chemical Engineering 2021年第6期34卷 1-11页

作者： Lingzhen Kong Jiaqing Chen Tian lan huan Sun Kuisheng Wang School of Mechanical Engineering Beijing Institute of Petrochemical TechnologyBeijing 102617China Beijing Key Laboratory of Pipeline Critical Technology and Equipment for DeepWater Oil&Gas Development Beijing 102617China College of Mechanical and Electrical Engineering Beijing University of Chemical TechnologyBeijing 100029China

For the design and optimization of a tubular gas-liquid atomization mixer,the atomization and mixing characteristics of liquid jet breakup in the limited tube space is a key *** this study,the primary breakup process of liquid jet columnwas analyzed by high-speed camera,then the droplet size and velocity distribution of atomized droplets were measured by Phase-Doppler anemometry(PDA).The hydrodynamic characteristics of gas flow in tubular gas-liquid atomization mixer were analyzed by computational fluid dynamics(CFD)numerical *** results indicate that the liquid flow rate has little effect on the atomization droplet size and atomization pressure drop,and the gas flowrate is themain influence *** all experimental gas flowconditions,the liquid jet column undergoes a primary breakup process,forming larger liquid blocks and *** the gas flow rate(Qg)is less than 127 m^(3)·h^(−1),the secondary breakup of large liquid blocks and droplets does not occur in venturi throat *** Sauter mean diameter(SMD)of droplets measured at the outlet is more than 140μm,and the distribution is *** Qg>127 m^(3)·h^(−1),the large liquid blocks and droplets have secondary breakup process at the throat *** SMD of droplets measured at the outlet is less than 140μm,and the distribution is *** 127

关键词： Atomization mixing Liquid jet Primary breakup Droplet breakup Droplet size

Synthesis of binaphthyl bridged chiral bis-corrole

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Chinese Chemical Letters 2009年第1期20卷 21-24页

作者： Ping Lian Hai Yang Liu lan Ying Liu Lei shi huan Feng Jiang Chi Kwong Chang Department of Chemistry and Life Sicence Gannan Normal University Ganzhou 341000 China Department of Chemistry South China University of Technology Guangzhou 510641 China Department of Chemistry The Hong Kong University of Science and Technology Hong Kong China

Chiral bis-corrole 1 and 2 were prepared by reaction of （s）-2,2′-bis（bromomethyl）-1, 1′-binaphthyl and 10-（4-hydroxylphenyl）- 5,15-bis（pentafluorophenyl）corrole or 10-（3-hydroxylphenyl）-5,15-bis（pentafluorophenyl）corrole in DMF at 60 ℃ in the presence of anhydrous K2CO3 with an isolated yield -8%. Both 1 and 2 exhibit unsymmetrical induced circular dichroism （ICD） in the soret band with positive exciton chirality.

关键词： Chiral bis-corrole Synthesis ICD

A method of improving SFDRs of 1-bit signals for a monobit receiver

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Journal of Systems Engineering and Electronics 2022年第2期33卷 330-339页

作者： JI Pengfei shi Qingzhan LV huan YUAN Naichang School of Electronic Sciences National University of Defense TechnologyChangsha 410073China

This paper proposes a method to improve the spu-rious-free dynamic ranges(SFDRs)of 1-bit sampled signals greatly,which is very beneficial to multi-tone signals ***,the relationship between the fundamental component and the third harmonic component of 1-bit sampled signals is analyzed for determining four contiguous special frequency bands,which do not contain any third harmonics inside and co-ver 77.8%of the whole Nyquist sampling frequency ***,we present a special 4-channel monobit receiver model,where appropriate filter banks are used to obtain four desired pass bands before 1-bit quantization and each channel can sample and process sampled data independently to achieve a good in-stantaneous dynamic range without sacrificing the real-time per-formance or computing *** simulation results show that the proposed method effectively eliminates the effect of the most harmonics on SFDRs and the mean SFDR is increased to to 20 ***,the multi-signals simulation results indicate that the maximum amplitude separation(dynamic range)of two signals in each channel is 12 dB while the proposed monobit re-ceiver can deal with up to eight simultaneous arrival *** general,the designing method proposed in this paper has a po-tential engineering value.

关键词： 1-bit signal monobit third harmonic component spurious-free dynamic range(SFDR)

Small Signal Gain in Tapered Free-Electron Lasers of Oscillator Configuration

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Chinese Physics Letters 1991年第10期8卷 511-514页

作者： shi Yijin lan Ke Institute of Atomic Energy Beijing 102413

A quadrature for small signal gain(SSG)in tapered free electron laser(FEL)is *** contrast to the uniform case,the optimum of gain is not at p=1.303 of energy misma,tchf and it depend on the *** the antenna array conceptj the spontaneous emission is derived and it shows that Madey's theorem is still *** generalization frojn one to three dimensions is given and degradation of SSG due to the collimation excursion of the axes of the opticalj electron beam and undulator can be included as *** comparision with Boeing's FEL experiment is carried out also.

关键词： antenna Small Electron

Effects of Coal Rank and High Organic Sulfur on the Structure and Optical Properties of Coal-based Graphene Quantum Dots

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Acta Geologica Sinica(English Edition) 2018年第3期92卷 1218-1230页

作者： TANG Yuegang huan Xuan lan Chunyuan XU Miaoxin College of geoscience and Surveying Engineering China University of Mining & Technology (Beijing) Beijing 100083 China

Coal-based graphene quantum dots(GQDs) were successfully produced via a one-step chemical synthesis from six different coal ranks, from which two superhigh organic sulfur(SHOS) coals were selected as natural S-doped carbon sources for the preparation of S-doped GQDs. The effects of coal properties on coal-based GQDs were analyzed by means of high-resolution transmission electron microscopy(HRTEM), X-ray diffraction(XRD), Fourier transform infrared(FTIR) spectroscopy, X-ray photoelectron spectroscopy(XPS), ultraviolet-visible(UV-Vis) absorption spectroscopy, and fluorescence emission spectra. It was shown that all coal samples can be used to prepare GQDs, which emit bluegreen and blue fluorescence under ultraviolet light. Anthracite-based GQDs have a hexagonal crystal structure without defects, the largest size, and densely arranged carbon rings in their lamellae; the highrank bituminous coal-based GQDs are relatively reduced in size, with their hexagonal crystal structure being only faintly visible; the low-rank bituminous coal-based GQDs are the smallest, with sparse lattice fringes and visible internal defects. As the metamorphism of raw coals increases, the yield decreases and the fluorescence quantum yield(QY) initially increases and then decreases. Additionally, the surface of GQDs that were prepared using high-rank SHOS coal(high-rank bituminous coal) preserves rich sulfur content even after strong oxidation, which effectively adjusts the bandgap and improves the fluorescence QY. Thus, high-rank bituminous coal with SHOS content can be used as a natural S-doped carbon source to prepare S-doped GQDs, extending the clean utilization of low-grade coal.

关键词： coal graphene quantum dots coal rank organic sulfur China