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Effects of an AMPS-modified Polyacrylic Acid Superplasticizer on the Performance of Concrete Materials

Journal of Wuhan University of technology(Materials Science) 2015年第1期30卷 533-540页

作者：陈宝璠 college of Civil Engineering Liming Vocational University Applied technology Engineering Center of Fujian Provincial High Education for Practical chemical Material Liming Vocational University

A self-made 2-acrylamide-2-methyl propylene sulfonic （AMPS）-modified polyacrylic acid superplasticizer and two other commercially available superplasticizers with different molecular structures are used in this study to investigate the effect of an AMPS-modified polyacrylic acid superplasticizer on the properties of concrete materials. In the experiments, initial and 1.5 h slumps over time after admixtion are determined by adding different dosages of three superplasticizers into the premixed concrete to characterize the slump loss resistance of the premixed concrete. The water-reducing rates of three different types of concrete are determined to characterize the water-reducing capacity of the concrete with each superplasticizer. The 3, 7 and 28 d compressive strength is determined to characterize the mechanical properties of the concrete with each superplasticizer. In the meanwhile, 1, 1.5 and 2.0 h slump loss rates over time after admixtion are determined by adding different dosages of the three superplasticizers into the high-performance concrete （HPC） to characterize the slump loss resistance of HPC. The 7, 28, 60 and 90 d compressive strength is determined to characterize the compressive properties of HPC with each superplasticizer. The dry shrinkage rates of three different types of HPC are determined with each superplasticizer. Electric flux after standard curing for 56 d and chloride ion diffusion coefficient after curing for 28 d of I-IPC are determined to characterize the impermeability of HPC with each superplasticizer. The cross-section was examined using a scanning electron microscopy （SEM） system. Results demonstrate that the AMPS-modified polyacrylic acid superplasticizer has better water-reducing effect and slump than the two commercially available polyacrylie acid superplasticizers. The AMPS-modified polyacrylic acid superplasticizer also shows significant improvement of the compressive strength, especially in comprehensive performance of HPC. In con

关键词： AMPS-modified polyacrylic acid superplasticizer concrete materials all-round properties,interface

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Basic Mechanical Properties and Microstructural Analysis of Recycled Concrete

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Journal of Wuhan University of technology(Materials Science) 2013年第1期28卷 104-109页

The regeneration aggregate, natural aggregate, POO42.5 R Portland cement, coal fly ash, and slag powders S95 graining blast furnace, homemade P（AA-co-MA）/PEG carboxylic acid water reducing agent, were used together with recycled concrete aggregate in different regeneration rates to prepare recycled concrete （RC）. The influences of different renewable aggregate ratios on the basic RC replacement mechanical properties, uniaxial compression stress and strain curve, and the elastic modulus and rebound value were *** results show that RC mechanical properties decreases with renewable aggregate replacement rate increasing. The prolongation can reduce the reduced span.

关键词： recycled concrete (RC) regeneration aggregate replacement rate mechanical properties uniaxial compression stress

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Photocatalytic H_2 evolution activity of CuO/ZrO_2 composite catalyst under simulated sunlight irradiation

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Journal of Central South University 2011年第1期18卷 56-62页

作者：阎建辉姚茂海张丽唐有根杨海华 Department of Chemistry and chemical Engineering Hunan Institute of Science and Technology college of Chemistry and chemical Engineering Central South University

Zirconia-supported CuO （CuO/ZrO2） composite photocatalysts were successfully synthesized via citric acid-assisted sol-gel technique. For comparison, CuO/ZrO2 materials were also prepared by solid state reaction and co-precipitation method. The as-prepared powders were characterized by X-ray diffractometry （XRD）, transmission electron microscopy （TEM）, and thermogravimetric-differential thermal analysis （TG-DTA）. The photocatalytic activity of CuO/ZrO2 catalyst was investigated based on the H2 evolution from oxalic acid solution under simulated sunlight irradiation. The effects of molar ratio of CuO to ZrO2, preparation method, phase change with the calcination temperature and the durability on the photocatalytic activity of the photocatalyst were investigated in detail. It is found that the optimal activity of photocatalytic H2 evolution （2.41 mmol.h i.g-~） can be obtained when CuO/ZrO2 composite photocatalyst is synthesized by sol-gel technique and the mole ratio of CuO to ZrO2 is 40%. The activity of copper oxide supported on monoclinic ZrO2 calcined at higher temperature is much higher than that on tetragonal ZrO2 calcined at lower temperature, and the best calcination temperature is 900 ℃.

关键词： CuO/ZrO2 photocatalytic activity hydrogen evolution simulated sunlight

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Hydrothermal Synthesis, Crystal Structure, Thermal Stability and Magnetic Properties of a Dinuclear Copper(Ⅱ) Complex

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Chinese Journal of Structural Chemistry 2015年第10期34卷 1553-1557页

作者：李昶红李薇胡汉祥胡波年 college of chemical Engineering Hunan Institute of Technology college of Chemistry and Materials Science Hengyang Normal University

A new dinuclear copper（Ⅱ） complex [Cu（CH3COO）（C7H5N4）（H2O）]2·3.5H2 O has been hydrothermally synthesized with copper acetate, o-acetamidobenzoic acid and 3-（pyridin-2-yl）-1,2,4-triazole. It crystallizes in the monoclinic space group P21/c, with a = 12.0188（7）, b = 13.7993（8）, c = 8.7488（5） A, β = 101.7350（10）o, V = 1420.67（14） A3, D3 c = 1.568 g/cm, Z = 1, F（000） = 690, the final GOOF = 1.145, R = 0.0437, and w R = 0.1097. The crystal structure shows that the whole molecule consists of two copper ions bridged by two μ2-η1：η0 3-（pyridin-2-yl）-1,2,4-triazole anions. The coordination environment of Cu（Ⅱ） ion is Cu O2N3, giving a distorted square pyramidal geometry. The thermal stability and magnetic properties of the complex were investigated.

关键词： copper(Ⅱ) complex thermal stability and magnetic properties

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Synthesis,Crystal Structure,Spectroscopic Characterization and Thermal Stability Properties of a Trinuclear Zinc(Ⅱ) Complex

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Chinese Journal of Structural Chemistry 2015年第9期34卷 1405-1409页

作者：李昶红李薇胡汉祥胡波年 college of chemical Engineering Hunan Institute of Technology college of Chemistry and Materials Science Hengyang Normal University

A new trinuclear zinc complex Zns（2,2＂-bipy）2（3,5-DMBA）6＂（H20）1.5 （1） with 3,5-dimethylbenzoic acid （3,5-DMBA） and 2,2＂-bipyridine as ligands has been synthesized in the mixed solvents of methanol and water. It crystallizes in the monoclinic space group C2/c with a = 31.1497（15）, b = 11.7576（6）, c = 20.9049（10） A, fl = 118.4550（10）°, V- 6731.4（6） A3, Dc = 1.412 g/cm3, Z = 4, F（000） = 2972, GOOF = 1.069, the final R= 0.0667 and wR= 0.1917. The whole molecule consists of three zinc ions, six 3,5-DMBA molecules, two 2,2＂-bipyridine molecules and one and half water molecules, in which three zinc ions are bridged by six μ2-η1：η0 carboxylate groups of 3,5-DMBA. The Zn（1） atom is centrosymmetric, and adopts a distorted octahedral ZnO6 geometry, while the Zn（2） gives a distorted square pyramidal ZnOsN2 geometry. The spectroscopic characterization and thermal stability properties of the complex were investigated.

关键词： trinuclear zinc(Ⅱ) complex spectroscopic characterization thermal stability

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Synthesis and Properties of an AMPS-Modified Polyacrylic Acid Superplasticizer

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Journal of Wuhan University of technology(Materials Science) 2013年第3期28卷 566-573页

A 2-acrylamide-2-methyl propylene sodium sulfonic （AMPS）-modified polyacrylic acid superplasticizer was synthesized using aqueous solution polymerization with the major monomers including the self-made active macromers polyethylene glycol mono-methyl ether acrylate acrylic （MPEGAA）, acrylic acid （AA）, AMPS, and sodium methyl allyl sulfonate （SMAS）. The ratios of the monomers were determined using an orthogonal experiment. This research focused on the effects of the dosages of different macromers, the polymerization conditions, and the length of MPEGAA side chains on the properties of the AMPS-modified polyacrylic acid super-plasticizer. The best polymerization conditions of the AMPS-modified polyacrylic acid superplasticizer are when （n（MPEGAA）：n（SMAS）：n（AMPS）：n（AA） equals 0.1：0.1：0.2：0.65, the molecular weight of monomethoxypolyethylene glycol is 1 200, the initiator ammonium persulfate accounts for 5% of the total mass of the polymerized monomers, the polymerization temperature is 80 ~C, and the reaction time is 4 h. The AMPS-modified polyacrylic acid superplasticizer synthesized in the best conditions exhibited excellent dispersivity and dispersion retainability. When the dosage ratio was 0.24%, the initial fluidity was 400 mm and the fluidity had nearly no loss after 1 h.

关键词： AMPS-modified polyacrylic acid superplasticizer copolymerization synthesis property

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Synthesis and Crystal Structure of 4-tert-Butyl-6-(4-chlorophenyl)-3,6-dihydro-2H-1,3-thiazin-2-iminium Chloride

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Chinese Journal of Structural Chemistry 2009年第1期28卷 33-36页

作者：夏林胡艾希曹高王宇叶姣 college of Chemistry and chemical Engineering Hunan University School of Chemistry and chemical Engineering South China University of Technology

The title compound, 4-tert-butyl-6-（4-chlorophenyl）-3,6-dihydro-2H-1,3-thiazin- 2-iminium chloride （C14H18C12N2S）, has been synthesized by the reaction of 1-（4-chlorophenyl）- 4,4-dimethylpent-1-en-3-one with thiourea, and its crystal structure was determined by single- crystal X-ray diffraction. The crystal belongs to the monoclinic system, space group P211c with a = 16.3064（11）, b = 9.4471（6）, c = 11.2626 （8）A, β = 108.400（1）°, Z = 4, V = 1646.28（19） A^3, Mr = 317.26, Dc = 1.280 g/cm^3, S = 1.078,μ = 0.510 mm^-1, F（000） = 664, the final R = 0.0514 and wR = 0.1412 for 3210 observed reflections （I 〉 2σ（I））. The thiazine ring system displays a twisted boat conformation, and three N-H,..Cl hydrogen bonds exist in the crystal. The combination of two N-H...Cl hydrogen bonds generate an R2^1 （6） ring.

关键词： crystal structure synthesis 4-tert-butyl-6-(4-chlorophenyl)-3,6-dihydro- 2H- 1,3-thiazin-2-iminium chloride

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Properties of high cis-1,4 content hydroxyl-terminated polybutadiene and its application in composite solid propellants

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Defence technology（防务技术） 2024年第10期40卷 199-209页

作者： Deqian Meng Lipeng Sang Pingan Zhang Jianru Deng Xiang Guo college of Chemistry and chemical Engineering Hunan UniversityChangsha410082China Science and technology on Aerospace chemical Power Laboratory Xiangyang441003China

In this paper,high cis-1,4 content hydroxyl-terminated polybutadiene(cis-HTPB)with different molecular weights was prepared through the oxidative cracking process using cis-butadiene rubber as raw ***,this article comprehensively compared the differences between cis-HTPB and conventional I-HTPB in terms of molecular weight distribution,functionality,viscosity,molecular polarity,and other physicochemical properties,which provided effective data support for its subsequent *** addition,the reaction kinetics study showed that cis-HTPB with isocyanate curing agent has high reactivity,allowing it to be rapidly cured at low temperatures,and the cured elastomers had excellent mechanical properties,with tensile strength and elongation up to 1.89 MPa and 1100%,*** was also found that cis-HTPB has extremely excellent low-temperature resistance,and the glass transition temperature(T_(g))of its cured elastomer is as low as-101℃.Based on the above studies,cis-HTPB is applied as a binder in composite solid propellants for the first time to investigate its practical performance,and the results indicated that cis-HTPB-based propellants have excellent process and mechanical properties.

关键词： High cis-1,4 content-HTPB(cis-HTPB) Low-temperature resistance Comparison of physicochemical properties cis-HTPB curing process cis-HTPB based propellant

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First-principle investigation on stability of Co-doped spinel λ-Mn_(4-x)Co_xO_8

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Journal of Central South University of technology 2007年第2期14卷 186-190页

作者：黄可龙陈春安刘素琴罗琼刘志国 college of Chemistry and chemical Engineering Central South University Department of Chemistry and chemical Engineering Hunan University of Technology

The mechanism of stability of Co-doped spinel λ-MnO_2 that is referred to as spinel Li_xMn_2O_4 (x=0) was studied by using the first-principle calculation method. The total energy and formation enthalpy can be decreased remarkably due to the Co substation, resulting in a more stable structure of λ-Mn_xCr_(2-x)O_4. The bond order and DOS analysis were given in detail to explain the nature of stability improvement. The calculated results show that as the content of Co dopant increases, the bond order of Mn—O becomes larger and the peak of density of states around Fermi level shifts toward lower energy. The charge density distribution illustrates that the Mn—O bonding is ionic and partially covalent, and the covalent Mn-O bonding becomes stronger with the increase of Co dopant content. The results confirm that the Codoping will enhance the stability of λ-MnO_2 and hence improve the electrochemistry performance of Li_xMn_2O_4.

关键词： first-principles stability electrochemical performance Co-doped λ-MnO2

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Fabrication of poly(2,6-pyridinedicarboxylic acid)/MWNTs modified electrode for simultaneous determination of guanine and adenine in DNA

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Chinese chemical Letters 2011年第8期22卷 981-984页

作者： Ke Qin Deng Chun Xiang Li Yu Lin Ling Guo Rong Xu Xiao Fang Li Chemistry and chemical Engineering college Hunan University of Science and Technology Xiangtan 411201 China

The fabrication of poly（2,6-pyridinedicarboxylic acid）/MWNTs modified glass electrode（PPDA/MWNTs/GCE） was proposed and used for individual or simultaneous determination of guanine and *** performances of the PPDA/MWNTs/GCE were characterized with cyclic voltammetry（CV）.The modified electrode exhibited enhanced electrocatalytic behavior and good stability for the detection of guanine and *** pulse voltammetry（DPV） was used to determine the concentration of guanine,*** detection limit（S/N = 3） for guanine and adenine was 0.045μmol/L and 0.05μmol/L,*** electrochemical method for the measurement of guanine and adenine in calf thymus DNA was also developed with this modified electrode and the result was satisfactory.

关键词： Multi-wall carbon nanotubes 2 6-Pyridinedicarboxylic acid Guanine Adenine Calf thymus dsDNA

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