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Non-linear Radical Additions-Coupling Polymerization of Monovinyl Monomers towards Polymer Networks: Theory, Tunability and Heritable Architecture

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Chinese Journal of Polymer Science 2022年第12期40卷 1623-1630,I0008页

作者： Li-mei Ren cheng-Lin Li Qi Wang MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science&Engineering Zhejiang UniversityHangzhou 310027China Current address:Zhejiang University-University of Edinburgh Institute Zhejiang University School of Medicineand Key Laboratory of Tissue Engineering and Regenerative Medicine of Zhejiang ProvinceZhejiang University School of MedicineHangzhou 310027China

Exploring new polymerization strategy for current available monomers is a big challenge in polymer science. Here we re-investigate radical polymerization of monovinyl monomer(MVM) initiated by uniform branched polyfunctional initiator(PFI), which is termed non-linear radical additions-coupling polymerization(NLRAs CP). In NLRAs CP, both addition and coupling reactions of radical contribute to the construction of the polymer chains, which leads to continuous growth of branch topology. Theoretical analysis of NLRAs CP predicts that the gelation is determined by the functionality of PFI(a), the extent of initiation of the PFI(q) and the termination factor of radical(φ). NLRAs CPs of styrene and methyl methacrylate promoted by Cu(0)/MeTREN or Mn_(2)(CO)_(10)/visible light were conducted. After the cleavage of incorporated PFI fragment or junctions in the network, the network was transformed to linear chains having almost the same structure as segmental chains in the precursor network. This allows the reverse deducing the network structure from its cleaved products. It has been proven that NLRAs CP includes stepwise initiation of PFI, chain-growth of segmental chains and successive endlinking of macroradicals derived from PFI. The three parameters related to the gelation process, a, q and φ, were adjusted via binary PFI, the feed ratio of [Mn_(2)(CO)_(10)]/[PFI] and addition of non-homopolymerizable comonomer respectively. The minimum values of a and q, and the minimum amount of comonomer required for gelation were determined,which can be applied to estimate φ of various macroradicals. NLRAs CP opens a general and facile strategy for synthesis of a variety of polymer networks with heritable architecture by one-pot polymerization of various MVMs.

关键词： Non-linear radical additions-coupling polymerization Monovinyl monomer Polyfunctional initiator Polymer network Theory

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Microstructure and mechanical properties of Ti-Cu amorphous coating synthesized on pure Cu substrate by mechanical alloying method

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Rare Metals 2020年第10期39卷 1222-1228页

作者： cheng Chen Xiao-mei Feng Yi-fu Shen School of Mechanical and Power Engineering Nanjing Tech UniversityNanjing 211800China College of Materials Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Mechanical alloying method was applied to fabricate coating with amorphous structure on pure Cu *** microstructure,the phase composition and the mechanical properties including microhardness and wear resistance of the coating were,respectively,characterized and *** results show that the coating is rough but *** has favorable adhesion to the *** coating is made up of an inner composite layer and an outer amorphous *** microhardness and the wear resistance of the pure Cu substrate are improved because of the bilayer *** formation mechanism of the coating was *** as-synthesized coating is considered to be effective to strengthen the surface of pure Cu substrate.

关键词： Coating Amorphous Mechanical alloying Surface reinforcement

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Seasonal bioconcentration of heavy metals in Onchidium struma(Gastropoda:Pulmonata)from Chongming Island,the Yangtze Estuary,China

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Journal of Environmental Sciences 2009年第2期21卷 255-262页

作者： LI Xiaobo JIA Linzhi ZHAO Yunlong WANG qun cheng Yongxu School of Life Science East China Normal University Shanghai 200062 China College of Aqua-life Science and Technology Shanghai Ocean University Shanghai 200090 China

The seasonal concentration changes of selected heavy metal Cd, Cr, Cu, Fe, Mn, Pb, and Zn in five tissues of marine gastropod Onchidium struma were studied in the Chongming Island, the Yangtze Estuary in April 2007, July 2006, September 2006, and November 2006, respectively. The results demonstrated that the bioconcentration factor of Cu （biomass/water） in all selected tissues was about 104 magnitudes, Fe and Cd were 103, Zn was 102, and Mn, Pb, and Cr were 101. Hepatopancreas was proven to be the dominant storage tissue of Cr, Cu, Mn, and Zn, whereas Fe and Pb were mainly stored in muscle and digenetic gland, and Cd was stored in vitelline gland and albumen gland. Additionally, it was found that Cu, Fe, Mn, and Zn were concentrated significantly by O. struma （whole-body） in summer or autumn, and Cd, Cr, and Pb increased slightly in spring and winter. Furthermore, the bioconcentration of Cr was nearly 2-fold higher and Zn was 1.6-fold higher in the water compared with the Water Quality Standard for Fisheries. With view of excessive amount of Pb, Cd, and Cu according to seafood standard, the consumption of O. struma might have the risk of health hazard.

关键词： Onchidium struma heavy metal bioconcentration the Yangtze Estuary

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Impact of ethanol on the flotation efficiency of imidazolium ionic liquids as collectors:Insights from dynamic surface tension and solvation analysis

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International Journal of Minerals,Metallurgy and Materials 2024年第12期31卷 2645-2656页

作者： Qian cheng Zerui Lei Guangjun mei Jianhua Chen Key Laboratory of Green Utilization of Critical Non-metallic Mineral Resources Ministry of EducationWuhan University of TechnologyWuhan 430070China MOE Key Laboratory of New Processing Technology for Non-ferrous Meta1s and Materials Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured MaterialsGuangxi UniversityNanning 530004China

To conduct extensive research on the application of ionic liquids as collectors in mineral flotation,ethanol(EtOH)was used as a solvent to dissolve hydrophobic ionic liquids(ILs)to simplify the reagent *** phenomena were observed in which EtOH exerted different effects on the flotation efficiency of two ILs with similar *** EtOH was used to dissolve 1-dodecyl-3-methylimidazolium chloride(C12[mim]Cl)and as a collector for pure quartz flotation tests at a concentration of 1×10^(−5)mol·L^(−1),quartz recovery increased from 23.77%to 77.91%compared with ILs dissolved in ***,quartz recovery of 1-dodecyl-3-methylim-idazolium hexafluorophosphate(C12[mim]PF6)decreased from 60.45%to 24.52%under the same *** conditional experi-ments under 1×10^(−5)mol·L^(−1)ILs for EtOH concentration and under 2vol%EtOH for ILs concentration confirmed this *** being affected by EtOH,the mixed ore flotation tests of quartz and hematite showed a decrease in the hematite concentrate grade and re-covery for the C12[mim]Cl collector,whereas the hematite concentrate grade and recovery for the C12[mim]PF6 collector *** the basis of these differences and observations of flotation foam,two-phase bubble observation tests were carried *** EtOH promoted the foam height of two ILs during *** accelerated static froth defoaming after aeration stopped,and the foam of C12[mim]PF6 de-foaming especially *** the discussion of flotation tests and foam observation,an attempt was made to explain the reasons and mechanisms behind the diverse phenomena using the dynamic surface tension effect and solvation effect results from *** solva-tion effect was verified through Fourier transform infrared(FT-IR),X-ray photoelectron spectroscopy(XPS),and Zeta potential ***-though EtOH affects the adsorption of ILs on the ore surface during flotation negatively,it holds an positive value of inhibiting foam mer-ging during flotation a

关键词： ionic liquid ethanol flotation foam solvation dynamic surface tension

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Enzymatic biosynthesis of novel neobavaisoflavone glucosides via Bacillus UDP-glycosyltransferase

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Chinese Journal of Natural Medicines 2017年第4期15卷 281-287页

作者： MA Tao DAI Yi-qun LI Nan HUO Qiang LI Hong-mei ZHANG Yu-Xin PIAO Zheng-Hao WU cheng-Zhu School of Pharmacy Bengbu Medical CollegeBengbu 233030China Department of Biochemistry Bengbu Medical CollegeBengbu 233030China Department of Basic Medical Science School of MedicineHangzhou Normal UniversityHangzhou 321004China

The present study was designed to perform structural modifications of of neobavaisoflavone(NBIF), using an in vitro enzymatic glycosylation reaction, in order to improve its water-solubility. Two novel glucosides of NBIF were obtained from an enzymatic glycosylation by UDP-glycosyltransferase. The glycosylated products were elucidated by LC-MS, HR-ESI-MS, and NMR analysis. The HPLC peaks were integrated and the concentrations in sample solutions were calculated. The MTT assay was used to detect the cytotoxic activity of compounds in cancer cell lines. Based on the spectroscopic analyses, the two novel glucosides were identified as neobavaisoflavone-4′-O-β-D-glucopyranoside(1) and neobavaisoflavone-4′, 7-di-O-β-D-glucopyranoside(2). Additionally, the water-solubilities of compounds 1 and 2 were approximately 175.1-and 4 031.9-fold higher than that of the substrate, respectively. Among the test compounds, only NBIF exhibited weak cytotoxicity against four human cancer cell lines, with IC50 values ranging from 63.47 to 72.81 μmol·L^(-1). These results suggest that in vitro enzymatic glycosylation is a powerful approach to structural modification, improving water-solubility.

关键词： Neobavaisoflavone Glycosylation UDP-glycosyltransferase Water-solubility Cytotoxicity

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Electrohydrodynamic behaviors of droplet under a uniform direct current electric field

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Chinese Physics B 2020年第3期29卷 312-317页

作者： Zi-Long Deng mei-mei Sun cheng Yu Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education School of Energy and EnvironmentSoutheast UniversityNanjing 210096China Department of Mechanical Engineering University of Hawaii at ManoaHonolulu 96822USA

The electrohydrodynamic behaviors and evolution processes of silicone oil droplet in castor oil under uniform direct current(DC)electric field are visually observed based on a high-speed microscopic ***,the effects of different working conditions,such as electric field strength,droplet size,etc.,on droplet behaviors are roundly *** can be found that there are four droplet behavior modes,including Taylor deformation,typical oblique rotation,periodic oscillation,and fracture,which change with the increase of electric field *** is also demonstrated that the degree of flat ellipse deformation gets larger under a stronger electric ***,both of the stronger electric field and smaller droplet size lead to an increase in the rotation angle of the droplet.

关键词： DC electric field droplet deformation rotation

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The Spectrum for Overlarge Sets of Hybrid Triple Systems

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Acta Mathematicae Applicatae Sinica 2014年第3期30卷 635-646页

作者： mei-hui cheng Zi-hong TIAN Huihua College of Hebei Normal University College of Mathematics and Information Science Hebei Normal University

A hybrid triple system of order v and index A, denoted by HTS（v, λ）, is a pair （X,B） where X is a v-set and B is a collection of cyclic triples and transitive triples on X, such that every ordered pair of X belongs to A triples of B. An overlarge set of disjoint HTS（v, λ）, denoted by OLHTS（v, λ）, is a collection {（Y／{y}, .Ai）}i, such that Y is a （v ＋ 1）-set, each （Y／{y}, Ai） is an HTS（v, λ,） and all Ais form a partition of all cyclic triples and transitive triples on Y. In this paper, we shall discuss the existence problem of OLHTS（v, A） and give the following conclusion： there exists an OLHTS（v, λ） if and only if λ= 1, 2, 4, v = 0, 1 （rood 3） and v ≥ 4.

关键词： overlarge set hybrid triple system hybrid candelabra system

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Boundedness of fractional integral operators on α-modulation spaces

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Applied Mathematics(A Journal of Chinese Universities) 2014年第3期29卷 339-351页

作者： WU Xiao-mei CHEN Jie-cheng Xingzhi Colledge Zhejiang Normal University Department of Mathematics Zhejiang Normal University

In this paper, we obtain the boundedness of the fractional integral operators, the bilineax fractional integral operators and the bilinear Hilbert transform on α-modulation spaces.

关键词： α-modulation space fractional integral operator bilinear fractional integral operator bilinearHilbert transform.

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Indecomposable Large Sets of Steiner Triple Systems with Indices 5, 6

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Acta Mathematica Sinica,English Series 2012年第11期28卷 2169-2184页

作者： mei Hui cheng Zi Hong TIAN Institute of Mathematics Hebei Normal University

A family （X, B1）,（X, B2）,..., （X, Bq） of q STS（v）s is a λ-fold large set of STS（v） and denoted by LSTSλ（v） if every 3-subset of X is contained in exactly A STS（v）s of the collection. It is indecomposable and denoted by IDLSTSx（v） if there does not exist an LSTSx, （v） contained in the collection for any λ 〈 λ. In this paper, we show that for λ = 5, 6, there is an IDLSTSλ（v） for v ≡ 1 or 3 （rood 6） with the exception IDLSTS6（7）.

关键词： Steiner triple system, large set, candelabra system indecomposable

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Luminescent properties of a new Nd^(3+)-doped complex with two different carboxylic acids and pyridine derivative

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Rare Metals 2013年第5期32卷 490-495页

作者： Yun-Xia Ye Li-Hua Wei Wei-Chen mei Chen Yin-qun Hua School of Mechanical Engineering Jiangsu University Institute of Laser Technology Jiangsu University School of Material Engineering Jiangsu University

A new Nd3＋-doped organic complex featuring two different perfluorinated carboxylic acids as the first ligand and pyridine derivative 2-amino-3-chloro-5-（tri- fluoromethyl）pyridine as the second ligand was designed and synthesized. Successful coordination between the ligands and central rare earth ions was confirmed by Fourier transform infrared spectroscopy （FT-IR） spectra, 1H nuclear magnetic resonance （1H NMR） spectra, and UV spectra, and the synthesized complex is inferred to be eight-coordinate structure. Solution of the complex dis- solved in DMSO-d6 was prepared and then its fluorescence spectrum, UV-Vis-NIR absorption spectrum, and fluorescence decay curve were tested. The fluorescent lifetime is about 7 txs. Based on the above experimental research, Judd-Ofelt analysis was carried out, and the results indi- cate that appropriate coordination environment around Nd3＋ in this solution results in a high fluorescent quantum efficiency 2 % and a large stimulated emission cross-section about 3.2 × 10^-20 cm^2 at 1,064 nm.

关键词： Nd Organic solution Liquid laser Quantum efficiency Judd-Ofelt theory

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