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The damage evolution behavior of polypropylene fiber reinforced concrete subjected to sulfate attack based on acoustic emission

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Frontiers of Structural and Civil Engineering 2022年第3期16卷 316-328页

作者： Ninghui LIANG Jinwang MAO ru yan Xinrong LIU Xiaohan ZHOU School of Civil Engineering Chongqing UniversityChongqing 400045China National Joint Engineering Research Center for Prevention and Control of Environmental Geological Hazards in the TGR Area Chongqing UniversityChongqing 400045China Power China Chengdu Engineering Corporation Ltd. Chengdu 610072China

To study the damage evolution behavior of polypropylene fiber reinforced concrete(PFRC)subjected to sulfate attack,a uniaxial compression test was carried out based on acoustic emission(AE).The effect of sulfate attack relative to time and fiber hybridization were analyzed and the compression damage factor was calculated using a mathematical *** changes to AE ringing counts during the compression could be divided into compaction,elastic,and AE signal hyperactivity *** the initial stage of sulfate attack,the concrete micropores and microcracks were compacted gradually under external load and a corrosion products filling effect,and this corresponded with detection of few AE signals and with concrete compression strength *** increasing sulfate attack time,AE activity *** cumulative AE ringing counts of PFRC at all corrosion ages were much higher than those for plain *** could still produce AE signals after peak load due to drawing effect of polypropylene *** 150 d of sulfate attack,the cumulative AE ringing counts of plain concrete went down by about an order of magnitude,while that for PFRC remained at a high *** initial damage factor of hybrid PFRC was-0.042 and-0.056 respectively after 150 d of corrosion,indicating that the advantage of hybrid polypropylene fiber was more obvious than plain concrete and single-doped *** on a deterioration equation,the corrosion resistance coefficient of hybrid PFRC would be less than 0.75 after 42 drying-wetting sulfate attack cycles,which was 40%longer than that of plain concrete.

关键词： polypropylene fiber reinforced concrete sulfate attack damage evolution behavior acoustic emission damage factor

Quinolinyl Imidazolidin-2-imine Nickel Catalyzed Efficient Copolymerization of Norbornene with para-Chlorostyrene

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Chinese Journal of Polymer Science 2020年第9期38卷 941-949,I0005页

作者： yan-Qing Li Jian Zhou ru Xiao Zheng-Guo Cai State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Material Science and EngineeringDonghua UniversityShanghai 201620China College of Biological and Chemical Engineering Guangxi University of Science and TechnologyLiuzhou 545006China

A series of novel quinolinyl imidazolidin-2-imine nickel complexes with different substituents on the imidazolidin-2-imine ligand were synthesized and *** complexes in the presence of methylaluminoxane(MAO)as a cocatalyst catalyzed the copolymerization of norbornene(N)and styrene(S)or para-chlorostyrene(CS)with high activity(up to 1070 kg·mol^-1·h^-1).The installation of sterically bulky substituents on the imidazolidine-2-imine ligand was effective for the increase of the molecular weight and the comonomer content,affording high molecular weight copolymers with tunable CS content(0.57 mol%-11.7 mol%),in which the existence of CI group can provide reaction site for the further functionalization of copolymers as well as the synthesis of graft or cross-linked *** linear relationship between the comonomer content and the glass transition temperature of the copolymers and the monomer reactivity ratios in the copolymerization indicated the formation of the expected functionalized cyclic olefin copolymers(COC).

关键词： Imidazolidin-2-imine ligand Nickel complex Norbornene para-Chlorostyrene Copolymerization

Elastic direct envelope inversion based on wave mode decomposition for multi-parameter reconstruction of strong-scattering media

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Petroleum Science 2022年第5期19卷 2046-2063页

作者： Pan Zhang ru-Shan Wu Li-Guo Han Yong hu College of Geo-exploration Science and Technology Jilin UniversityChangchun 130026JilinChina Modeling and Imaging Laboratory Earth&Planetary ScienceUniversity of California at Santa CruzSanta CruzCalifornia95064USA School of Resources and Geosciences China University of Mining and TechnologyXuzhou 221008JiangsuChina

The parameter reconstruction of strong-scattering media is a challenge for conventional full waveform inversion(FWI).Direct envelope inversion(DEI)is an effective method for large-scale and strongscattering structures imaging without the need of low-frequency seismic ***,the current DEI methods are all based on the acoustic ***,in real cases,seismic records are the combined effects of the subsurface ***,the study of DEI in elastic media is necessary for the accurate inversion of strong-scattering structures,such as salt *** this paper,we propose an elastic direct envelope inversion(EDEI)method based on wave mode *** define the objective function of EDEI using multi-component seismic data and derive its gradient *** reduce the coupling effects of multi-parameters,we introduce the wave mode decomposition method into the gradient calculation of *** update of Vp is primarily the contributions of decomposed *** approaches on Vs gradient calculation are proposed,*** the petrophysical relation and wave mode decomposition ***,we test the proposed method on a layered salt model and the SEG/EAGE salt *** results show that the proposed EDEI method can reconstruct reliable large-scale Vp and Vs models of strong-scattering salt *** successive elastic FWI can obtain high-precision inversion results of the strong-scattering salt *** proposed method also has a good anti-noise performance in the moderate noise level.

关键词： Direct envelope inversion Full waveform inversion Elastic wave Strong-scattering media Multi-parameter

Lithium intercalation mechanism for β-SnSb in Sn-Sb thin films

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International Journal of Minerals,Metallurgy and Materials 2011年第2期18卷 216-222页

作者： Qiang ru Qin Tian She-jun hu Ling-zhi Zhao Laboratory of Quantum Information Technology School of Physics and Telecommunication Engineering South China Normal University Guangzhou 510006 China Department of Chemistry South China Normal University Guangzhou 510006 China

Based on the first-principles plane wave pseudo-potential method, the electronic structure and electrochemical performance of LixSn4Sb4 （x=2, 4, 6, and 8） and LixSn12-xSb4 （x=9, 10, 11, and 12） phases were calculated. A Sn-Sb thin film on a Cu foil was also prepared by radio frequency magnetron sputtering. The surface morphology, composition, and lithium intercalation/extraction behavior of the fabricated film were characterized by scanning electron microscopy （SEM）, X-ray diffraction （XRD） and cyclic voltammetry （CV）. Lithium atoms can easily insert into and extract out of the β-SnSb cell due to the low lithium intercalation formation energy. It is found that lithium atoms first occupy the interstitial sites, and then Sn atoms at the lattice positions are replaced by excessive lithium. The dissociative Sn atoms continue to produce different Li-Sn phases, which will affect the electrode stability and lead to the undesirable effect due to their large volume expansion ratio. The calculated lithium intercalation potential is stable at about 0.7 V, which is consistent with the experimental result.

关键词： lithium batteries first-principles Sn-Sb alloys electronic structure thin films

Study of lithium storage properties of the Sn-Ni alloys prepared by magnetic sputtering technology

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Acta Metallurgica Sinica(English Letters) 2010年第5期23卷 363-369页

作者： Xianhua HOU Shejun hu Wei PENG Zhiwen ZHANG Qiang ru School of Physics and Telecommunication Engineering South China Normal University Guangzhou 510006 China

Nano-level Sn-Ni alloy thin-film electrode materials prepared by magnetic sputtering technology are characterized with X-ray diffraction （XRD）, atom force microscopy （AFM） and scanning electron microscopy （SEM）. The charge/discharge and cyclic voltammograms （CV） of the films electrodes are tested by the battery testing system of high precision. The results indicate that the materials prepared by direct current （DC） and radio frequency （RF） methods differ greatly in their performance. Ni3Sn2 alloy phase constitutes the main components prepared by DC method, the particles on the surface are tiny and show steady cycling performance, the deficiency is that they have low initial efficiency and small discharge capacity of 72% and 108 mA·h/g, respectively. Contrary to the former, Ni3Sn4 alloy phase constitutes the main com- ponents prepared by RF method, the particles on the surface appear comparatively larger, their discharge capacity did not decline in the first 15 times, keeping above 500 mA·h/g, but began to decline after 15 times.

关键词： Lithium ion battery Sn-Ni alloy Electrochemical property

The Degenerated Second Main Theorem and Schmidt's Subspace Theorem

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Science China Mathematics 2012年第7期55卷 1367-1380页

作者： CHEN Zhihua ru Min yan QiMing Department of Mathematics Tongji University Shanghai 200092 China Department of Mathematics University of Houston Houston TX 77004 USA

In this paper, we establish a Second Main Theorem for an algebraically degenerate holomorphic curve f : C → Pn(C) intersecting hypersurfaces in general position. The related Diophantine problems are also considered.

关键词： Nevanlinna theory holomorphic curve Second Main Theorem Diophantine approximation Schmidt's Subspace Theorem

High-level theoretical study of the evolution of abundances and interconversion of glycine conformers

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Chinese Physics B 2018年第4期27卷 264-271页

作者： Fan Liu Jing Yu yan-ru huang College of Science Liaoning Shihua University Fushun 113001 China

The relative conformer energies of glycine are evaluated by using a focal point analysis expressed as（HF→MP2→MP3→CCSD→CCSD（T））.The conformer abundances at various temperatures（298–500 K） are calculated based on the relative energies and Boltzmann statistical thermostatistical analysis with and without considering internal hindered rotations.A comparison between the available Raman spectrum and the electron momentum spectrum confirms that the influence of rigid-rotor hindered rotation on the conformational proportions of glycine is considerable,especially for the IIIp *** conformational interconversions are *** is found that with increasing temperature,the mole fraction of IIn keeps constant and Ip structure can convert into IVn and IIIp,leading to the decrease in the weight of Ip and the increase in the weights of IVn and IIIp conformers,which is in accordance with experimental observations.

关键词： glycine conformation abundance interconversion

Biosorption of cesium(Ⅰ) from aqueous solution by a novel exopolymers secreted from Pseudomonas fluorescens C-2: Equilibrium and kinetic studies

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Journal of Environmental Sciences 2011年第7期23卷 1104-1112页

作者： yanli Mao Hongwei hu Yongsheng yan School of Chemistry and Chemical Engineering Jiangsu University Zhenjiang 212013 China School of Environmental and Municipal Engineering Department Henan University of Urban Construction Pingdingshan 467000 China

The biosorption characteristics of Cs（I） ions from aqueous solution using exopolymers （PFC02） produced from Pseudomonas fluorescens C-2 were investigated as a function of pH, biosorbent dosage, contact time and initial concentration. pH played a major role in the adsorption process, and the optimum pH for the removal of Cs（I） was 8.0. Langmuir, Freundlich and Dubinin-Radushkevich （D-R） models were applied to describe the biosorption isotherm of the Cs（I） ions by PFC02. The Lagergren first-order, pseudo second-order kinetic and intraparticle diffusion models were used to test the kinetic data. Langmuir model and D-R model fitted the equilibrium data better than the Freundlich isotherm. The monolayer adsorption capacities of PFC02 as obtained from Langmuir isotherm at 25°C was found to be 32.63 mg/g. From the D-R isotherm model, the mean free energy was calculated as 26.73 kJ/mol, indicating that the biosorption of cesium was chemisorption. The biosorption process was rapid, and the kinetic rates were best fitted to the pseudo second-order model, which indicated the biosorption process operated through chemisorption mechanism. FT-IR analysis of PFC02 showed the possible functional groups responsible for cesium adsorption were hydroxyl, carboxyl, carbonyl and sulphonate groups. SEM analysis showed the porous structure of the material while EDX analysis confirmed the adsorption of Cs（I） on PFC02. Cesium adsorbed onto the PFC02 could be desorbed efficiently using 1 mol/L HNO 3 , and the enrichment factor was 50.0. Furthermore, PFC02 could be reused five times with only about 8.25% regeneration loss. The developed method was successfully utilized for the removal of Cs（I） ions from aqueous solution.

关键词： Pseudomonas fluorescens C-2 exopolymers Cs(I) biosorption isotherm kinetics

Cyproheptadine Regulates Pyramidal Neuron Excitability in Mouse Medial Prefrontal Cortex

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Neuroscience Bulletin 2018年第5期34卷 759-768页

作者： yan-Lin He Kai Wang Qian-ru Zhao yan-Ai Mei Institutes of Brain Science State Key Laboratory of Medical Neurobiology and School of Life Sciences Fudan University

Cyproheptadine （CPH）, a first-generation anti- histamine, enhances the delayed rectifier outward K＋ current （IK） in mouse cortical neurons through a sigma-1 receptor-mediated protein kinase A pathway. In this study, we aimed to determine the effects of CPH on neuronal excitability in current-clamped pyramidal neurons in mouse medial prefrontal cortex slices. CPH （10 μmol/L） significantly reduced the current density required to generate action potentials （APs） and increased the instan- taneous frequency evoked by a depolarizing current. CPH also depolarized the resting membrane potential （RMP）, decreased the delay time to elicit an AP, and reduced the spike threshold potential. This effect of CPH was mim- icked by a sigma-1 receptor agonist and eliminated by an antagonist. Application of tetraethylammonium （TEA） to block IK channels hyperpolarized the RMP and reduced the instantaneous frequency of APs. TEA eliminated the effects of CPH on AP frequency and delay time, but had no effect on spike threshold or RMP. The current-voltage relationship showed that CPH increased the membrane depolarization in response to positive current pulses and hyperpolarization in response to negative current pulses, suggesting that other types of membrane ion channels might also be affected by CPH. These results suggest that CPH increases the excitability of medial prefrontal cortex neurons by regulating TEA-sensitive IK channels as well as other TEA-insensitive K＋ channels, probably ID and inward-rectifier Kir channels. This effect of CPH may explain its apparent clinical efficacy as an antidepressant and antipsychotic.

关键词： Cyproheptadine Neuronal excitability Te-traethylammonium-sensitive Ik cortical neurons Sigma-1 receptor