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Science China Chemistry 2018年第1期61卷 71-75页

作者： pengfei sun Sichao Tian Mingchang Lin Guosong Chen Key Laboratory for Organic Electronics and Information Displays & Institute of Advanced Materials Jiangsu National Synergetic Innovation Center for Advanced Materials Nanjing University of Posts & Telecommunications The State Key Laboratory of Molecular Engineering of Polymers and Department of Macromolecular Science Fudan University

This work investigated the effect of glyco-regioisomerism of glycopolymers on their dynamic interaction with benzoxaborole-containing polymers. Two kinds of glycopolymers, P-1-Gal and P-6-Gal, i.e. galactoside pendant group linked to the identical main chain through its anomeric(C1) and C6-hydroxyl group position, respectively, were studied. We found that P-6-Gal showed stronger binding strength to the PNIPAM-co-PBOB polymer than P-1-Gal did, which controlled the macroscopic property of the resultant hydrogels at a molecular level.

关键词： glyco-regioisomerism benzoxaborole glycopolymers hydrogel glucose

Enhanced strength-ductility of CoCrFeMnNi high-entropy alloy with inverse gradient-grained structure prepared by laser surface heat-treatment technique

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Journal of Materials Science & Technology 2022年第16期111卷 111-119页

作者： Bohong Zhang Jie Chen pengfei Wang Bingtao sun Yu Cao College of Mechanical&Electrical Engineering Wenzhou UniversityWenzhou 325035China

The inverse gradient-grained CoCrFeMnNi high-entropy alloy with a desirable mechanical property that evades the strength-ductility trade-off is fabricated by the process of cold rolling and subsequent laser surface *** to the gradually decayed thermal effect along with the thickness,the grain size increases from the hard core to the soft surface in terms of the inverse gradient-grained sample,which is in good consistent with the microhardness *** hetero-deformation induced strengthening and strain hardening caused by the inverse gradient-grained structure improve the strength-ductility combination,as well as the high-order hierarchal nanotwins due to the enhanced interaction with *** the laser surface heat-treatment technique,the strength and ductility are significantly increased by enlarging the microhardness difference and decreasing the thermal *** the high volume fraction of gradient-grained layer and a great deal of high-order hierarchal nanotwins in the central region,the laser surface heat-treatment technique is a promising way to produce the gradientstructured materials without thickness limitation.

关键词： High-entropy alloy Laser surface heat-treatment Cold rolling Inverse gradient-grained structure Strength-ductility combination

Modified Layer-Removal Method for Measurement of Residual Stress in Pre-stretched Aluminium Alloy Plate

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Journal of Harbin Institute of Technology(New Series) 2015年第2期22卷 34-40页

作者： Liangbao Liu Jianfei sun Wuyi Chen pengfei sun School of Mechanical Engineering and Automation Beihang University

Residual stress is one of the factors affecting the machining deformation of monolithic structure parts in the aviation industry. Thus, the studies on machining deformation rules induced by residual stresses largely depend on correctly and efficiently measuring the residual stresses of workpieccs. A modified layer-removal method is proposed to measure residual stress by analysing the characteristics of a traditional, layer-removal method. The coefficients of strain release are then deduced according to the simulation results using the finite element method （FEM）. Moreover, the residual stress in a 7075T651 aluminium alloy plate is measured using the proposed method, and the results are then analyzed and compared with the data obtained by the traditional methods. The analysis indicates that the modified layer-removal method is effective and practical for measuring the residual stress distribution in pre-stretched aluminium alloy plates.

关键词： pre-stretched aluminium alloy plate residual stress finite dement method(FEM) modified layer-removal

Highly selective detection of copper(Ⅱ) by a “ligand-free” conjugated copolymer in nucleophilic solvents

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Frontiers of Chemical Science and Engineering 2020年第1期14卷 105-111页

作者： Weixing Deng pengfei sun Quli Fan Lei Zhang Tsuyoshi Minami Key Laboratory for Organic Electronics and Information Displays&Jiangsu Key Laboratory for Biosensors Institute of Advanced Materials(IAM)Jiangsu National Synergetic Innovation Center for Advanced Materials(SICAM)Nanjing University of Posts&TelecommunicationsNanjing 210023China Institute of Industrial Science The University of TokyoMeguro-kuTokyo 153-8505Japan

The synthesis of N-cyclohexyl carbamate-attached fluorene-alt-phenylene copolymer(PFPNCC)and the use of PFPNCC as a“ligand-free”fluorescent chemosensor for Cu(Ⅱ)are *** of Cu(Ⅱ)can efficiently quench the fluorescence of PFPNCC in nucleophilic solvents such as DMF and DMSO,but not in low nucleophilic solvents such as 1,4-dioxane and ***-visible spectra of the mixture of the conjugated polymer and Cu(Ⅱ)indicate the presence of a reduced Cu(Ⅰ)ion in the ***,fluorescence recovery of PFPNCC observed at low temperature suggests that the quenching and reducing mechanism is most probably due to a photo-induced electron transfer from excited PFPNCC to Cu(Ⅱ).Our findings provide a novel strategy for highly selective conjugated polymer-based chemosensors for various target analytes,albeit“ligand-free”.

关键词： ligand-free fluorescent chemosensor copper photo-induced electron transfer

Improving the high cycle fatigue property of Ti6Al4V ELI alloy by optimizing the surface integrity through electric pulse combined with ultrasonic surface rolling process

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Journal of Materials Science & Technology 2024年第3期170卷 103-121页

作者： pengfei sun Shengguan Qu Chenfeng Duan Xiongfeng Hu Xiaoqiang Li National Engineering Research Center of Near-Net-Shape Forming for Metallic Materials South China University of TechnologyGuangzhou 510640China School of Mechanical and Automotive Engineering South China University of TechnologyGuangzhou 510640China

To improve the surface integrity and high cycle fatigue property of Ti6Al4V ELI alloy,the electric pulse has been introduced into the ultrasonic surface rolling process(USRP),which is called electric pulse-assisted ultrasonic surface rolling process(EUSRP).With the help of“electroplasticity”of the electric pulse,the thickness of the surface gradient deformation layer was about three times of the USRP specimens by adjusting the pulse current ***,the surface hardness decreases due to the continuous effect of the pulse current and the“skin effect”during *** is worth noting that the higher the applied pulse current,the more severe the *** paradox causes the fatigue performance of EUSRP specimens lower than that of USRP *** break this paradox,the EUSRP treatment is followed by a USRP *** EUSRP-2(with a pulse current of 200 A)+USRP specimens exhibit excellent surface hardness,a gradient deformation layer thickness of about 400μm,low surface roughness and high compressive residual compressive ***,the hardening mechanisms of the different surface strengthening specimens have been quantitatively analyzed in combination with microstructure *** fatigue life of Ti6Al4V ELI alloy can be improved by about 25 times at 780 MPa using the EUSRP-2+USRP treatment,the main reason for the highest fatigue life is the deepest surface gradient layer and the deepest crack initiation *** fatigue limit of the EUSRP-2+USRP specimens is not the highest because too much surface hardening causes compressive residual stress relaxation during cycling and the beneficial effect of compressive residual stress is eliminated.

关键词： Ti6Al4V ELI alloy Combined surface treatment Transmission electron microscopy Residual stress Fatigue performance

Kinetic analysis and bacterium metabolization of α-pinene by a novel identified Pseudomonas ***

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Journal of Environmental Sciences 2012年第10期24卷 1806-1815页

作者： Zhuowei Cheng pengfei sun Yifeng Jiang Lili Zhang Jianmeng Chen Engineering Research Center of the Ministry of Education for Bioconversion and Biopurificationm Zhejiang University of Technology Hangzhou 310032 China. College of Biological and Environmental Engineering Zhejiang University of Technology Hangzhou 310032 China

Biodegradation has become a popular alternative remediation technology for its economic and ecological advantages. An aerobic bacterium （strain ZW） capable of degrading α-pinene was isolated from a biofilter by a selective enrichment. Based on the 16S rRNA gene analysis and physiochemical properties, this strain was identified as Pseudomonas veronii. Under the optimized condition achieved by the response surface methodology （RSM）, as well as pH 6.82, temperature 26.3℃ and NaC1 concentration 1.36%, almost 100% α-pinene could be removed within 45 hr. Enzymatic biodegradation by the crude intracellular enzyme could be described well by the Michaelis-Menten model in which the maximum degradation rate Vraax and the half-saturation constant Km were calculated to be 0.431 mmol/（***） and 0.169 mmol/L, respectively. Activity assay of catechol suggested that the strain ZW possessed a catechol- 1,2-dioxygenase and could decompose benzene-ring through ortho ring cleavage. Based on the identified intermediates by GC/MS, a new metabolic pathway was proposed, in which the final metabolites were some simpler organic and inorganic compounds. The present work demonstrated that the strain ZW would have a great application prospect for the remediation of α-pinene-contaminated environment.

关键词： Pseudomonas veronii ct-pinene growth conditions kinetics analysis metabolic pathway

Improvement in the liquid zinc corrosion resistance of high Nb-TiAl alloys by pre-oxidation in a SiO_2-powder pack

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Science China(Technological Sciences) 2012年第2期55卷 505-509页

作者： sun pengfei ZHANG LaiQi ZHANG Li LIN JunPin State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China

The influence of pre-oxidation on the liquid zinc corrosion resistance of high Nb-TiAl alloys was investigated. The pre-oxidation was performed by heating the specimens, buried in silica powder and encapsulated in a silica tube under a vacuum of 1.3x10-5 Pa at 950℃ for 12 h. Experimental results showed that the preoxidized sample exhibited much higher liquid zinc corrosion resistance than that for the comparative samples. This excellent liquid zinc corrosion resistance was attributed to the formation of high-quality oxide scale during peroxidation. The corrosion of all the samples in liquid zinc was caused by a localized breakdown in the oxide scales. The continuous and dense oxide scale formed during preoxidation substantially may prevent the liquid zinc from diffusing to the substrate, and its good continuity may also reduce the possibility of localized breakdown in the oxide scale.

关键词： liquid zinc corrosion preoxidation TiAI-Nb intermetallic compound

Mussel-inspired PTW@PDA composites for developing high-energy gun propellants with reduced erosion and enhanced mechanical strength

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Defence Technology（防务技术） 2024年第2期32卷 675-690页

作者： Xijin Wang Zhitao Liu pengfei sun Feiyun Chen Bin Xu Xin Liao School of Chemistry and Chemical Engineering Nanjing University of Science and TechnologyNanjing 210094JiangsuChina China North Industries Group Corporation Limited Beijing 100045China

The severe erosion and inadequate mechanical strength are prominent challenges for high-energy gun *** address it,novel PTW@PDA composites was prepared by polydopamine(PDA)-modifying onto potassium titanate whisker(PTW,K_(2)Ti_(6)O_(13)),and after was incorporated into gun propellant as erosion-reducing and mechanical-reinforcing *** interfacial characterizations results indicated that as-prepared PTW@PDA composites exhibits an enhanced surface compatible with propellant matrix,thereby facilitating their dispersion into propellants more effectively than raw PTW *** to original propellants,PTW@PDA-modified propellants exhibited significant less erosion,with a Ti-Kbased protective coating being detected on the eroded *** 0.5 wt%and 1.0 wt%addition of PTW@PDA significantly improved impact,compressive and tensile strength of *** the inevitably reduction in relative force,PTW@PDA slightly increase propellant burning rate while exerting little adverse impact on propellant dynamic *** strategy can provide a promising alternative to develop high-energy gun propellant with less erosion and more mechanical strength.

关键词： High energy gun propellant Potassium titanate whiskers Polydopamine modification Erosion inhibitors Mechanical reinforcing fillers

Microphysical Insights into a Tornadic Supercell from Dual-Polarization Radar Observations in Jiangsu, China on 14 May 2021

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Journal of Meteorological Research 2024年第2期38卷 303-320页

作者： Chao YUAN Yang BAI pengfei sun Hua BAI Lu XIA China Meteorological Administration Tornado Key Laboratory Foshan 528315 Institute of Atmospheric Environment China Meteorological AdministrationShenyang 110166 Panjin National Climate Observatory Panjin 124010 Yangzhou Meteorological Bureau of Jiangsu Province Yangzhou 225100 Yichun Meteorological Bureau of Heilongjiang Province Yichun 153000

Tornadoes are incredibly powerful and destructive natural events,yet the microphysical characteristics of the parent storm and its effects on tornadogenesis remain *** study analyzed polarization radar data of a tornadic supercell that occurred in Jiangsu Province of China on 14 May 2021,in comparison with another tornadic supercell and two non-tornadic supercells that occurred in the same region in *** two tornadic supercells exhibited lower differential reflectivity(ZDR)in the hook echo region compared with the non-tornadic supercells,indicating smaller median drop sizes.A distinct increase in ZDR from the melting of frozen hydrometeors,observed between2.5-and 4.0-km altitude in the non-tornadic storms,was absent in the tornadic *** non-tornadic supercells also displayed substantially higher specific differential phase(KDP)below the melting level,likely aroused from enhanced melting and *** findings suggest fundamental microphysical contrasts between tornadic and nontornadic ***,tornadic supercells have smaller droplets and may reduce melting in hook ***,greater separation between the ZDR arc and the KDP foot was observed during *** vertical gradient of KDP related to the cooling pool strength of the hook echo,regulating rear-flank downdraft *** the limited number of cases investigated,the findings of this study indicate that monitoring ZDR,KDP,and drop size distribution trends could assist with tornado prediction and warnings.

关键词： tornado polarimetric radar supercell hook echo drop size distribution

Effects of Silver Nanoparticles on Denitrification and Associated N_(2)O Release in Estuarine and Marine Sediments

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Journal of Ocean University of China 2022年第1期21卷 131-140页

作者： sun pengfei LI Kuiran YI Shaokui LI Hui CHEN Xi Fourth Institute of Oceanography Ministry of Natural ResourcesBeihai 536000China College of Environmental Science and Engineering Ocean University of ChinaQingdao 266100China College of Marine Life Science Ocean University of ChinaQingdao 266003China College of Life Sciences Huzhou UniversityHuzhou 313000China

Silver nanoparticles(AgNPs)have been widely used in medicine and consumer *** it enters the river in dif-ferent ways,then finally converges to the ocean through the *** polution can affect NO_(2)−and N_(2)O production by denitri-fiers in aquatic *** effects of AgNPs on denitrification activity,nitrogen transformation and nitrous oxide(N_(2)O)emission were investigated in Dagu River Estuary(DRE)and Jiaozhou Bay(JZB).The results showed that the potential denitrification activity(PDA),NO_(3)−and NO_(2)−reduction rates decreased with an increase of AgNPs concentration in DRE and ***,the N_(2)O ac-cumulation was significantly increased at AgNPs concentrations above 5 mg kg^(−1)in both areas,and the accumulation rate was greater in estuary than in bay(P0.05)in DRE and ***,the relative abundance of narG,nirS and nosZ gene in two areas decreased with the increase of AgNPs concentration,and the negative effect of AgNPs varied in order:nosZ>nirS>narG,inferring that the expression of denitrifying related genes could be significantly and differently inhibited by AgNPs ***,this study demon-strated that the inhibitory effect of AgNPs on different denitrification process,which may lead to the increase of inorganic nitrogen accumulation and N_(2)O *** study provides a scientific basis for the further studies of AgNPs on the ecological impact mechanism and environmental effects of offshore sedimentary environment.

关键词： nitrous oxide silver nanoparticles denitrification estuarine and marine sediments