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Early Hydration and Setting Process of Fly Ash-blended Cement Paste under Different Curing Temperatures

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Journal of Wuhan University of Technology(Materials Science) 2020年第3期35卷 551-560页

作者： zhang Wenhua WU Fan zhang yunsheng Civil Engineering Department Nanjing Forestry UniversityNanjing 210037China Department of Materials Science and Engineering Southeast UniversityJiangsu Key Laboratory of Construction MaterialsNanjing 211189China

A specially developed ultrasonic measurement apparatus (UMA) was used to in situ monitor the setting process of fly ash blended cement paste. Combined with the results of Vicat Needle tests, isothermal calorimetric measurement, XRD analysis, SEM morphology and compressive test, the influence of curing temperature (20, 40, 60, and 90 ℃) and fly ash content (0,10%, 20% and 30%) on the setting and hydration process of fly ash blended cement paste was analyzed. The results show that setting and hardening process of fly ash blended cement paste at elevated temperature can be clearly identified into three stages including dormant stage, acceleration stage and deceleration stage. The increasing of curing temperature greatly accelerates the setting and hardening process. However, the content of fly ash does not have significant effect on the setting in condition of 90 ℃. Besides, the initial and final setting time of cement paste is correspondent with the time of duration of dormant stage and the time of UPV value is 1500 m/s (T1500), respectively. Thus, the UMA can be used to determine the initial and final setting time of cementitious material under different curing temperatures. The compressive test results indicate that the paste with 20% fly ash presents higher compressive strength than the plain paste at curing temperatures of 90 ℃. Therefore, appropriate amount of fly ash is beneficial for concrete in the high temperature curing conditions.

关键词： ultrasonic setting and hardening process curing temperature fly ash microstructure

Infrared Spectroscopy Study of Structural Nature of Geopolymeric Products

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Journal of Wuhan University of Technology(Materials Science) 2008年第4期23卷 522-527页

作者： zhang yunsheng SUN Wei LI Zongjin College of Materials Science and Engineering Southeast University Nanjing 210096 China Department of Civil Engineering Hong Kong University of Science and Technology Kowloon China

The bonding status and chemical environment of SiO4 and AlO4 tetrahedras of three types of geopolymeric products were systematically investigated by infrared spectroscopy. The relationship between amorphous geopolymeric products and zeolite crystals with the same overall chemical compositions was also discussed. The infrared evidence shows that SiO4 tetrahedra is partially bonded by AlO4 during the hydration process of geopolymeric cement. The two types of tetrahedras jointly construct the three dimensional framework structures of the geopolymeric products. The mutual transformation between geopolymeric products and corresponding zeolite crystals will take place once the reaction condition is suitable, which reveals that the nature ofgeopolymeric products are probably the amorphous equivalent of the corresponding zeolite crystals.

关键词： geopolymeric products zeolite crystals infrared analysis microstructure

Web Resources for Pharmacogenomics

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Genomics, Proteomics & Bioinformatics 2015年第1期13卷 51-54页

作者： Guoqing zhang yunsheng zhang Yunchao Ling Jia Jia Shanghai Center for Bioinformation Technology

Pharmacogenomics is the study of the impact of genetic variations or genotypes of individuals on their drug response or drug metabolism. Compared to traditional genomics research,pharmacogenomic research is more closely related to clinical practice. Pharmacogenomic discoveries may effectively assist clinicians and healthcare providers in determining the right drugs and proper dose for each patient, which can help avoid side effects or adverse reactions, and improve the drug therapy. Currently, pharmacogenomic approaches have proven their utility when it comes to the use of cardiovascular drugs, antineoplastic drugs, aromatase inhibitors, and agents used for infectious diseases. The rapid innovation in sequencing technology and genome-wide association studies has led to the development of numerous data resources and dramatically changed the landscape of pharmacogenomic research. Here we describe some of these web resources along with their names, web links, main contents, and our ratings.

关键词： Pharmacogenomics Pharmacogenetics Drug response Adverse reaction

Numerical calculation and influencing factors of the volume fraction of interfacial transition zone in concrete

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Science China(Technological Sciences) 2012年第6期55卷 1515-1522页

作者： SUN GuoWen SUN Wei zhang yunsheng LIU ZhiYong Jiangsu Key Laboratory of Construction Materials Southeast UniversityNanjing 211189China

The determination of volume fraction of interracial transition zone （ITZ） is very important for investigating the quantitative relationship between the microstructure and macroscopical property of concrete. In this paper, based on Lu and Torquato＇s most nearest surface distribution function, a calculating process of volume fraction of ITZ is given in detail according to the actual sieve curve in concrete. Then, quantitative formulas are put forward to measure the influencing factors on the ｜TZ vol- ume fraction. In order to validate the given model, the volume fractions of ITZ obtained by numerical calculation are compared with those by computer simulation. The results show that the two are in good agreement. The order of the factors influencing the ITZ volume fraction is the ITZ thickness, the volume fraction of aggregate and the maximum aggregate diameter for Fuller gradation in turn. The 1TZ volume fraction obtained from the equal volume fraction （EVF） gradation is always larger than that from the Fuller gradation for a given volume fraction of aggregate.

关键词： concrete interfacial transition zone (ITZ) volume fraction Fuller distribution equal volume fraction distribution(EVF) sieve curve

In-situ Monitoring the Setting Behavior of Foamed Concrete Using Ultrasonic Pulse Velocity Method

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Journal of Wuhan University of Technology(Materials Science) 2013年第6期28卷 1146-1154页

作者： SHE Wei zhang yunsheng JONES MR GUO Panpan Jiangsu Key laboratory for Construction Materials Southeast University Concrete Technology Unit Division of Civil EngineeringUniversity of Dundee

The applicability of ultrasonic pulse velocity （UPV） method to in-situ monitor setting and hardening process of foamed concrete （FC） was systematically investigated. The UPVs of various FC pastes were automatically and continuously measured by a specially designed ultrasonic monitoring apparatus （UMA）. Ultrasonic tests were performed on FC mixtures with different density （300, 500, 800 and 1 000 kg/m3）, and different fly ash contents （0%, 20%, 40% and 60%）. The influence of curing temperatures （20, 40, 60 and 80~C） was also studied. The experimental results show that three characteristic stages can be clearly identified during the setting process of an arbitrary FC paste： dormant stage, acceleration stage, and deceleration stage. Wet density, fly ash content, and curing temperature have great impact on setting behavior. A stepwise increase of the wet density results in shorter dormant stage and larger final UPV. Hydration reaction rate is obviously promoted with an increase in curing temperature. However, the addition fly ash retards the microstn,lcture formation. To aid in comparing with the ultrasonic results, the consistence spread test and Vicat needle test （VNT） were also conducted. A correlation between ultrasonic and VNT results was also established to evaluate the initial and final setting time of the FC mixtures. Finally, certain ranges of UPV with reasonable widths were suggested for the initial and final setting time, respectively.

关键词： foamed concrete (FC) early age setting behavior ultrasonic monitoring setting time consistence

A comparative investigation of NdSrCu_(1-x) Co_x O_(4-δ) and Sm_(1.8) Ce_(0.2) Cu_(1-x) Co_x O_(4-δ) (x:0–0.4) for NO decomposition

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Journal of Environmental Sciences 2010年第3期22卷 448-453页

作者： Jiguang Deng Lei zhang yunsheng Xia Hongxing Dai Hong He Laboratory of Catalysis Chemistry and Nanoscience Department of Chemistry and Chemical Engineering College of Environmental and Energy EngineeringBeijing Unversity of Technology Beijing 100124 China.

A series of single-phase T-structured NdSrCu 1-x Co x O 4-δ with oxygen vacancies and T -structured Sm 1.8 Ce 0.2 Cu 1-x Co x O 4-δ （x： 0–0.4） with oxygen excess were prepared using ultrasound-assisted citric acid complexing method, and characterized by means of techniques such as thermogravimetric analysis and NO temperature-programmed desorption （NO-TPD）. The catalytic activities of these materials were evaluated for the decomposition of NO. It was found that the NdSrCu 1-x Co x O 4-δ catalysts were of oxygen vacancies whereas the Sm 1.8 Ce 0.2 Cu 1？x Co x O 4-δ ones possessed excessive oxygen （i.e., over-stoichiometric oxygen）; with a rise in Co doping level, the oxygen vacancy density of NdSrCu 1-x Co x O 4-δ decreased while the over-stoichiometric oxygen amount of Sm 1.8 Ce 0.2 Cu 1-x Co x O 4-δ increased. The NO-TPD results revealed that NO could be activated much easier over the oxygen-deficient perovskite-like oxides than over the oxygen-excessive perovskite-like oxides, with the NdSrCuO 3.702 catalyst showing the best efficiency in activating NO molecules. Under the conditions of 1.0% NO/helium, 2800 hr -1 , and 600–900°C, the catalytic activity of NO decomposition followed the order of NdSrCuO 3.702 〉 NdSrCu 0.8 Co 0.2 O 3.736 〉 NdSrCu 0.6 Co 0.4 O 3.789 〉 Sm 1.8 Ce 0.2 Cu 0.6 Co 0.4 O 4.187 〉 Sm 1.8 Ce 0.2 Cu 0.8 Co 0.2 O 4.104 〉 Sm 1.8 Ce 0.2 CuO 4.045 , in concord with the sequence of decreasing oxygen vacancy or oxygen excess density. Based on the results, we concluded that the higher oxygen vacancy density and the stronger Cu 3＋ /Cu 2＋ redox ability of NdSrCu 1-x Co x O 4-δ account for the easier activation of NO and consequently improve the catalytic activity of NO decomposition over the catalysts.

关键词： perovskite-like oxide catalysts NO decomposition oxygen nonstoichiometry Cu^ 3+ /Cu ^2+ Cu^ 2+ /Cu^ +

Preparation and Performance of Chitosan/Citric Acid Modified Magnesium Oxychloride Cement

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Journal of Wuhan University of Technology(Materials Science) 2023年第6期38卷 1326-1334页

作者： SONG Zijian LIU Lang YU Peipei zhang yunsheng LI Xincheng CHU Hongqiang JIANG Linhua College of Mechanics and Materials Hohai UniversityNanjing 2100China School of Civil Engineering Lanzhou University of TechnologyLanzhou 730050China Yunnan Institute of Building Research Co. LtdKunming 650223China

Citric acid(CA)and chitosan(CS)were employed to modify magnesium oxychloride cement(MOC).Multiscale measurements were implemented to study the properties of the modified MOC *** show that the addition of CA/CS significantly changes the content of each phase and the microstructure of phase *** single addition of CA can effectively increase the compressive strength of MOC after 7 d curing,while CS exerts no obvious effect on the compressive *** to the simultaneous addition of CA and CS,the compressive strength of MOC gradually decreases with the increasing content of ***,mixing CA and CS significantly enhances the water resistance of MOC and decreases the degradation rate of MOC in phosphate buffered solution,which can be ascribed to the low specific surface area of the plate-like crystals in the modified MOC and the reduction of pores in the structure.

关键词： magnesium oxychloride cement modifier citric acid chitosan

An Experimental Study on Constant Current Load Test of Reinforced Concrete based on 3D Paraffin Isolation

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Journal of Wuhan University of Technology(Materials Science) 2023年第2期38卷 353-365页

作者： SHANG Minggang XUE Cuizhen zhang yunsheng HEZhongmao QIAO Honzxin PENG Qiong Theogene Hakuzweyezu HAN Zhao School of Civil Engineering Lanzhou University of TechnologyLanzhou730050China Gansu Advanced Civil Engineering Materials Engineering Research Center Lanzhou730050China College of Science&Technology Ningbo University Ningbo315211China Institute of Rock and Soil Mechanics Chinese Academy of SciencesWuhan430071China

Aiming at the complex corrosion degradation factors of reinforced concrete and clearing the deterioration mechanism in the constant stress state,a new type of constant current accelerated corrosion method in the saline soil environment was *** three-dimensional paraffin isolation specimens and the three-dimensional penetration specimens were taken as the research objects,and the Cl−content and AC impedance Bode diagram were *** macro morphology and micro analysis were also used to evaluate the corrosion degradation laws of the two groups of specimens.A constant current three-factor system accelerated model was established for the current acceleration factor,chloride ion,and sulfate ion acceleration *** experimental results show that,in the constant stress test of the saline soil environmental conditions,the paraffin isolation layer can effectively isolate corrosive chloride ions,which is a brand-new research method of single factor variable control in the constant stress *** to the basic corrosion data,the law of constant current acceleration test is summarized and divided into five corrosion degradation stages,and each stage has significant changes in the accelerated corrosion *** corrosion degradation of a constant stress test is the combined effect of constant current,positive and negative penetration of chloride ions and sulfate ions.

关键词： Cl−content AC impedance constant stress test acceleration factor full factor life cycle

Construction of fluorescent hyperbranched polysiloxane-based clusteroluminogens with enhanced quantum yield and efficient cellular lighting

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Aggregate

Aggregate 2023年第2期4卷 227-236页

作者： Tian Bai yunsheng zhang Lan Wang Hongxia Yan Wenhao Zhou Shaanxi Key Laboratory of Biomedical Metallic Materials Northwest Institute for Non-Ferrous Metal ResearchXi’anP.R.China Key Laboratory of Polymer Science and Technology of Shaanxi Province School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’anP.R.China

Owing to its designability and intrinsic fluorescence,non-conjugated hyperbranched polysiloxane(HBPSi)has attracted widespread attention in biological filed,while it is still severely restricted by low fluorescence ***,in this paper,we introduced disulfide into HBPSi improving their luminescence properties and synthesized different molecular weight HBPSi(P1,P2,and P3).Surprisingly,P1 exhibited ultrahigh quantum yield up to 47.81%.Meanwhile,experiments applied with theoretical calculations were employed to explore the fluorescence mechanism,which is attributed to efficient restricting of non-radiative decay by clusteroluminogens formed with the cooperation of hyperbranched structure and double hydrogen *** addition,the biocompatibility of P1 was verified by co-culture with MC3T3-E1 and P1 lighted up mouse fibroblast cells without fluorescent *** work designed a novel fluorescent polymer with ultrahigh fluorescence quantum yield and cell imaging ability,which is promising in visualization diagnosis and treatment of tumor.

关键词： cell imaging fluorescence hyperbranched polysiloxane