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Journal of Rare Earths 2021年第5期39卷 495-503页

作者： Luozhen Jiang Xin Tao Li'na Li Wen Xia Rui si Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201204China university of Chinese Academy of Sciences Beijing 100049China Division of China TILON Group Technology LimitedShanghai 200090China

Ceria supported platinum catalyst has now been widely studied due to its excellent activity for CO oxidatio ***,the electron state of active metal center is still an open *** this work,a ce ria nanorod support was prepared and platinum(Pt)with 0.9 at%was deposited using an impregnation method to obtain Pt/CeO_(2)*** the help of"light-off"experiment and temperatureprogrammed reduction under CO(CO-TPR)test,the conclusion is proposed that the process of hydrogen reduction can enhance the activity of CO oxidation reaction for the generation of optimal active Pt *** innovative near-situ X-ray absorption fine structure(XAFS)technique was used to investigate the chemical state of central Pt atom during the reaction process,clearly demonstrating that the high oxidized state of Pt does harm to the activity for CO oxidation while the relatively reductive Pt exhibits high activity,and the different oxidized state and chemical environment of Pt during every process has been ***,the activity of our Pt/CeO_(2)catalyst is superior to that of most of the previous reports ab.ut CO catalytic oxidation by Pt based ***,the optimal active species(Pt-O_(4))have been identified after hydrogen reduction,which could be a possible key strategy to control the oxidation of Pt.

关键词： Platinum catalyst Ceria support CO oxidation Structure-activity relationship X-ray absorption fine structure Rare earths

Controlled synthesis and closed-loop chemical recycling of biodegradable copolymers with composition-dependent properties

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Science China Chemistry 2022年第5期65卷 943-953页

作者： Yi-Teng Yan Gang Wu si-Chong Chen Yu-Zhong Wang The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials(MoE) National Engineering Laboratory ofEco-Friendly Polymeric Materials(Sichuan)State Key Laboratory of Polymer Materials EngineeringCollege of ChemistrySichuan UniversityChengdu 610064China

The closed-loop recycling concept of the polymer wastes into building-block chemicals is attractive,but the closed-loop recycling of copolymers enabled by energy-efficient chemical recycling and cost-effective separations is still facing great ***,for the first time,a one-pot sequential copolymerization of γ-butyrolactone(γ-bL) and p-dioxanone(PDO)using an economical ureas/alkoxides catalytic system is conducted to synthesize biodegradable and chemically recyclable poly-(γ-butyrolactone)-block-poly(p-dioxanone)(PγbL-b-PPDO) diblock copolymers with well-defined and controlled *** composition-dependent properties of PγbL-b-PPDO copolymers,including thermal properties and crystallization behavior,are *** results show that the thermal stability and crystalline ability of PγbL are enhanced observably by introducing the PPDO ***,the PγbL-b-PPDO copolymers can be depolymerized efficiently into the corresponding co-monomers with a yield of over 95% by simply low-temperature pyrolysis under ***,γ-bL and PDO monomers are selectively separated with an isolated purity of ab.ut 99% based on the difference in their physicochemical ***,their repolymerization is realized to obtain the copolymers with nearly identical structures and thermostability,demonstrating the closed-loop recycling of copolymers,i.e.,*** research provides important guidance for the design of novel sustainable polymers towards more efficient chemical recycling,separation and regeneration.

关键词： biodegradable copolyester poly(p-dioxanone) tunable properties closed-loop chemical recycling

Chemically recyclable copolyesters from bio-renewable monomers:controlled synthesis and composition-dependent applicable properties

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Science China Chemistry 2023年第7期66卷 2062-2069页

作者： Wan-Ting Xiong Gang Wu si-Chong Chen Yu-Zhong Wang The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials(MoE) National Engineering Laboratory of Eco-Friendly Polymeric Materials(Sichuan)State Key Laboratory of Polymer Materials EngineeringCollege of ChemistrySichuan UniversityChengdu 610064China

The development of chemically recyclable polymers is a promising solution to address the dual challenges of the environment and resources caused by petroleum-based *** recent advancements,it is highly desirable for developing recyclable polymers to meet the requirements of both practical uses and well-performed ***-renewable monomers have been paid great attention recently as promising potential candidates for establishing a sustainable circular polymer ***,a sequential copolymerization of various bio-renewable n-alkyl substituted δ-valerolactone((R)VLs)and p-dioxanone(PDO)is conducted to synthesize novel chemically recyclable diblock copolymers poly(p-dioxanone)-block-poly(n-alkyl-valerolactones)(PPDO-b-P(R)VLs)with well-defined and controlled *** properties of copolymers including thermal property,crystallization,mechanical property,hydrophilicity and transport property can be tuned effectively to meet the requirements of practical uses by alternating the alkyl substituents(R)and the P(R)VLs *** addition,the high-efficiency and facile chemical recycling of copolymers to PDO and(R)VL comonomers is realized with a high yield of>96.5%and a high purity of 99%.

关键词： bio-renewable monomers ring-opening polymerization block copolyester tunable properties chemical recyclability

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Low-temperature densification of high-entropy(Ti,Zr,Nb,Ta,Mo)C-Co composites with high hardness and high toughness

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Journal of Advanced Ceramics 2022年第5期11卷 805-813页

作者： si-Chun LuO Wei-Ming GuO Kevin PLuCKNETT Hua-Tay LIN School of Electromechanical Engineering Guangdong University of TechnologyGuangzhou 510006China School of Mechanical and Electronic Engineering Pingxiang UniversityPingxiang 337000China Department of Process Engineering and Applied Science Dalhousie UniversityHalifax B3J1ZICanada

In order to prepare high toughness(Ti,Zr,Nb,Ta,Mo)C ceramics at low temperatures while maintaining high hardness,a liquid-phase sintering process combined with Co-based liquid-phase extrusion strategy was adopted in this *** densification temperature can be lowered to 1350℃,which is much lower than the solid-state sintering temperature(~2000℃)generally employed for high-entropy carbide *** sintered at 1550℃and 30 MPa applied pressure,part of the Co-based liquid-phase was squeezed out of the graphite mold,such that only~3.21 vol%of Co remained in the high-entropy *** to the Co-free solid-state sintered(Ti,Zr,Nb,Ta,Mo)C ceramics,prepared at 2000℃and 35 MPa,the hardness was slightly decreased from 25.06±0.32 to 24.11±0.75 GPa,but the toughness was increased from 2.25±0.22 to 4.07±0.13 MPa·m^(1/2).This work provides a new strategy for low-temperature densification of high-entropy carbides with both high hardness and high toughness.

关键词： high-entropy carbide ceramics liquid-phase sintering microstructure grain size mechanical properties

Potential Effect of Conservation Tillage on Sustainable Land use: A Review of Global Long-Term Studies

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Pedosphere 2006年第5期16卷 587-595页

作者： WANG Xiao-bin CAI Dian-Xiong W.b.HOOGMOED O.OENEMA u.D.PERDOK State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 （China） Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences Beijing 100081 （China） Farm Technology Group Wageningen University P. O. Box 17 6700 AA Wageningen （The Netherlands） Soil Quality Group Wageningen University P.O.Box 8005 6700 EC Wageningen （The Netherlands）

Although understood differently in different parts of the world, conservation tillage usually includes leaving crop residues on the soil surface to reduce tillage. Through a global review of long-term conservation tillage research, this paper discusses the long-term effect of conservation tillage on sustainable land use, nutrient availability and crop yield response. Research has shown several potential benefits associated with conservation tillage, such as potential carbon sequestration, nutrient availability, and yield response. This research would provide a better perspective of the role of soil conservation tillage and hold promise in promoting application of practical technologies for dryland farming systems in China.

关键词： conservation tillage no-till reduced tillage residue management

Synthesis and Some Properties of Metal Organic Chemical Vapour Deposited Molybdenum Oxysulphide Thin Films

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Journal of Materials Science & Technology 2010年第6期26卷 552-557页

作者： b.Olofinjana G.O.Egharevba M.A.Eleruja C.Jeynes A.V.Adedeji O.O.Akinwunmi b.A.Taleatu C.u.Mordi E.O.b.Ajayi Department of Physics Obafemi Awolowo UniversityIle-IfeNigeria Department of Chemistry Obafemi Awolowo UniversityIle-IfeNigeria Department of Electronic and Electrical Engineering University of SurreyGuildfordSurrey GU2 5XHUK Department of Chemistry and Physics Elizabeth City State UniversityElizabeth CityNC 27909USA

Molybdenum oxodithiocarbamate was prepared as thin films which were deposited on sodalime glass a single solid source precursor for molybdenum oxysulphide substrates using metal organic chemical vapour deposition （MOCVD） technique at a temperature of 420~C. Rutherford backscattering spectroscopy （RbS） was used to determine the elemental composition of the film which showed that the films contained large amounts of oxygen. The large amount of oxygen was attributed to the large abundance of oxygen in the starting material. A direct optical energy gap of 3.31 eV was obtained from the analysis of the absorption spectrum. The scanning electron microscopy （SEM） micrographs of the films showed that the films were continuous and porous. An estimated average size of the grains was below 5 #m. X-ray diffraction （XRD） showed that the deposited films were crystalline in nature.

关键词： Molybdenum oxodithiocarbamate Molybdenum oxysulphide Metal organic chemical vapour deposition (MOCVD) Thin film

Separation of growth-stimulating peptides for bifidobacterium from soybean conglycinin

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World Journal of Gastroenterology 2005年第37期11卷 5801-5806页

作者： Wei-Yong Zuo Wei-Hua Chen si-Xiang Zou Key Laboratory of Animal Physiology and biochemistry Ministry of Agriculture College of Veterinary Medicine Nanjing Agricultural University Nanjing 210095 Jiangsu Province China

AIM： To isolate and identify the soybean conglycinin peptides that selectively stimulates the growth of bifidobacteria in vitro, and to investigate the effect of soybean conglycinin peptides on intestinal ecosystem in vivo. METHODS： Soybean conglycinin was purified from soybean seeds by gel filtration （Sepharose-CL-6b）. These proteins were submitted to hydrolysis by pepsin. Several growth-stimulating peptides for bifidobacteria were isolated chromatographically from pepsin hydrolysis of soybean conglycinin and identified by means of matrixassisted laser desorption ionization time of flight mass spectrometry （MALDI-TOF-MS）. Parallel to in vitro study, in vivo experiments with soybean conglycinin peptides were performed in mice. Ninety male KM mice were randomly assigned into five groups of 16 mice each, and each group was administered for 21d intragastrically with physiological saline （control）, conglycinin, pepsin-treated conglycinin （PTC）, the most active fraction which isolated from pepsin-treated conglycinin （P2-PTC） and HCl-full hydrolysis of conglycinin （HCl-FHC）, respectively. Intestinal microflora were evaluated by standard microbiologic methods and biochemical assays of cecal content samples after treatment. RESuLTS： The results showed that the peptides which were isolated from soybean conglycinin could stimulate the growth of bifidobacteria in vitro, and the molecular mass of purified peptides with MALDI-TOF-MS ranged from 693.32 to 1829.55. Compared with control group, in vivo experiments showed that P2-PTC group decreased cecal pH （7.08±0.08 vs7.21±0.09, P〈0.05） and enterococcicounts （5.38±0.26 log10CFu/g vs 5.78±0.19 log10CFu/g, P〈0.05）, significantly increased sigA level （172.08±35.40 ng/g vs 118.27±33.93 ng/g, P〈0.01） and β-galactosidase activity （1.28±0.23 u/g vs 1.82±0.58 u/g, P〈0.05） CONCLusiON： The results have shown that conglycinin is good source for enzyme-mediated production of peptides which stimulate the growth of bifidobacteria. These peptid

关键词： Conglycinin pepsin peptides bifidobacteria

biological and mechanical investigation of novel flax/silk protein-based nanofibrous scaffold for bone regeneration

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Progress in Natural Science:Materials International 2022年第4期32卷 443-455页

作者： M.Rama u.Vijayalakshmi Department of Chemistry School of Advanced Sciences Vellore Institute of Technology

The process of bone tissue regeneration involves an intricate network of a biological macromolecules that includes proteins and peptides to support stimulation and healing response. Here, we have fabricated a novel flaxseed/silk fibroin based(dual protein) composite nanofibers using β-TCP to improve the biological properties and promote cartilage tissue regeneration along with a controllable rate of biodegradation. The physiochemical properties of PVA/β-TCP/FP:SF were characterized by FTIR, XRD, SEM, porosity, contact angle measurements and mechanical evaluation etc. This study demonstrates the biological performance of the developed nanofibers by using hemocompatibility, biodegradation ability, and apatite deposition in stimulated body fluid. Moreover, the cell viability assay was performed on MG-63 osteoblast cells and long-term antibacterial rate against E. coli and S. aureus was analysed. Docking results of flax protein and silk fibroin protein further confirmed the stable modes of intramolecular bonding and the most stable electrostatic values using theoretical calculations. Taken together,the experimental results proved that the dual protein-based fibrous scaffold was found to be up-regulated in terms of biological activity with enhanced cell adhesion and proliferation.

关键词： Flax protein silk fibroin β-TCP Electrospinning Docking bone regeneration

Fujita Type Conditions to Heat Equation with Variable Source

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Acta Mathematicae Applicatae sinica 2017年第1期33卷 63-68页

作者： Yun-xia LIu Yun-hua WANG si-ning ZHENG School of Mathematical Sciences Dalian University of Technology School of Mathematical Sciences Harbin Normal University

This paper studies heat equation with variable exponent ut = △u ＋ up（x） 4- uq in RN × （0, T）, where p（x） is a nonnegative continuous, b.unded function, 0 〈 p- = infp（x） ≤ p（x） ≤ supp（x） = p＋. It is easy to understand for the problem that all nontrivial nonnegative solutions must be global if and only if max{p＋,q} ≤1. based on the interaction between the two sources with fixed and variable exponents in the model, some Fujita type conditions are determined that that all nontrivial nonnegative solutions blow up in finite time if 0 〈 q ≤ 1 with p＋〉 1, or 1 〈 q 〈 1 ＋2/N. In addition, if q 〉 1 ＋2/N, then （i） all solutions blow up in finite time with 0 〈 p- ≤ p＋ ≤ 1 ＋2/N; （ii） there are both global and nonglobal solutions for p- ≤ 1 ＋ 2/N; and （iii） there are functions p（x） such that all solutions blow up in finite time, and also functions p（x） such that the problem possesses global solutions when p＋〈 1＋2/N 〈 p＋.

关键词： variable source Fujita type condition heat equation global solutions blow-up

Semileptonic and nonleptonic decays of b_(u,d,s)^(*) in the covariant light-front approach

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Chinese Physics C 2024年第12期48卷 20-36页

作者： si-Yang Wang You-Ya Yang Zhi-Jie Sun Hao Yang Peng Li Zhi-Qing Zhang Institute of Particle Physics and Key Laboratory of Quark and Lepton Physics(MOE) Central China Normal UniversityWuhan 430079China Institute of Theoretical Physics School of SciencesHenan University of TechnologyZhengzhou 450001China Institute for Complexity Science Henan University of TechnologyZhengzhou 450001China

The semileptonic and nonleptonic decays of the b-flavor vector mesons b_(u,d,s)^(*) and b_(c)^(*) are investigated within the covariant light-front quark model(CLFQM).by calculating the form factors of the transitions b_(u,d,s)^(*)→P under the CLFQM,with P denoting a pseudoscalar meson,i.e.,π,K,η_(c)(1S,2S),D_((s)),b_((s)),we predict and discuss several physical observables,including the branching ratios,polarization fractions f_(L),f_(∥),and forward-backward asymmetries A_(Fb).The total widths of the single-photon radiative decay channels for these b-flavor vector mesons are estimated using their partial *** these considered decays,one can find that the semileptonic decays b_(s)_(*0)→D_(s)^(-)l′+ν_(l′)and b_(c)^(*+)→b_(s)^(0)l′+ν_(l′),η_(c)l′+ν_(l′),with l′being e orτ,and the nonleptonic channels b*+c→b0sπ+,b0sρ+have the largest branching ratios,which can reach up to the 10^(-7) order,and are most likely to be accessible at the future high-luminosity LHCb and belle-II experiments.

关键词： b-flavor vector mesons b^(*) covariant light-front quark model branchig ratio