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| 1 | Dense packing properties of mineral admixtures in cementitious material显示文摘The effect of ultra-fine fly ash (UFFA),steel slag (SS) and silica fume (SF) on packing density of binary,ternary and quaternary cementitious materials was studied in this paper in terms of minimum water requirement of cement. The influence of mineral admixtures on the relative density of pastes with low water/binder ratios was analyzed and the relationship between paste density and compressive strength of the corresponding hardened mortars was discussed. The results indicate that the incorporation of mineral admixtures can effectively improve the packing density of cementitious materials; the increase in packing density of a composite with incorporation of two or three kinds of mineral admixtures is even more obvious than that with only one mineral admixture. Moreover,an optimal amount of mineral admixture imparts to the mixture maximum packing density. The dense packing effect of a mineral admixture can increase the packing density of the resulting cementitious material and also the density of paste with low water/binder ratio,which evidently enhances the compressive strength of the hardened mortar. | Yanzhou Peng Shuguang Hu Qingjun Ding | 2009 | Particuology2009，7，5： | 18 |
| 2 | Research on Startup Reliability of Ultrasonic Motors显示文摘作为一种在航空航天和武器系统有着广泛用途的新型微电机,超声电机的启动可靠性影响了其进一步的推广应用。该文通过理论分析将影响电机可靠启动的因素定位为定、转子摩擦界面阻力的增加以及定子的非线性振动,其中摩擦界面阻力增加包括摩擦材料嵌入定子槽中以及摩擦材料与定子的粘接。结合仿真分析和实验研究,证明超声电机定子振动的非线性是影响电机可靠启动的根本原因,越靠近共振频率非线性越严重,而定、转子接触界面的粘接以及摩擦材料嵌入定子齿使定子谐振频率升高,也就使原有工作频率更接近共振频率,从而导致电机定频启动困难。最后提出利用定子振动的非线性,采取降频启动的方法,可有效提高电机启动可靠性,为超声电机的推广应用打下良好基础。 | LI Huafeng DING Qingjun CHEN Chao | 2013 | 中国电机工程学报2013，33，9： | 7 |
| 3 | Effect of Curing Regime on Degree of Al^(3+) Substituting for Si^(4+) in C-S-H Gels of Hardened Portland Cement Pastes显示文摘The effect of curing regime on degree of Al3+ substituting for Si4+(Al/Si ratio) in C-S-H gels of hardened Portland cement pastes was investigated by 29Si magic angel spinning(MAS) nuclear magnetic resonance(NMR) with deconvolution technique. The curing regimes included the constant temperature(20, 40, 60 and 80 ℃) and variable temperature(simulated internal temperature of mass concrete with 60 ℃ peak). The results indicate that constant temperature of 20 ℃ is benefi cial to substitution of Al3+ for Si4+, and Al/Si ratio changes to be steady after 180 d. The increase of Al/Si ratio at 40 ℃ is less than that at 20 ℃ for 28 d. The other three regimes of high temperature increase Al/Si ratio only before 3 d, on the contrary to that from 3 to 28 d. However, the 20 ℃ curing stage from 28 to 180 d at variable temperature regime, is benefi cial to the increase of Al/Si ratio which is still lower than that at constant temperature regime of 20 ℃ for the same age. A nonlinear relation exists between the Al/Si ratio and temperature variation or mean chain length(MCL) of C-S-H gels, furthermore, the amount of Al3+ which can occupy the bridging tetrahedra sites in C-S-H structure is insuffi cient in hardened Portland cement pastes. | 胡晨光 胡曙光 DING Qingjun FENG Xiaoxin HUANG Xiulin | 2014 | Journal of Wuhan University of Technology(Materials Science)2014，29，3： | 5 |
| 4 | Analysis of the Quality of Daily DEM Generation with Geosynchronous InSAR显示文摘Up-to-date digital elevation model(DEM)products are essential in many fields such as hazards mitigation and urban management.Airborne and low-earth-orbit(LEO)space-borne interferometric synthetic aperture radar(InSAR)has been proven to be a valuable tool for DEM generation.However,given the limitations of cost and satellite repeat cycles,it is difficult to generate or update DEMs very frequently(e.g.,on a daily basis)for a very large area(e.g.,continental scale or greater).Geosynchronous synthetic aperture radar(GEOSAR)satellites fly in geostationary earth orbits,allowing them to observe the same ground area with a very short revisit time(daily or shorter).This offers great potential for the daily DEM generation that is desirable yet thus far impossible with space-borne sensors.In this work,we systematically analyze the quality of daily GEOSAR DEM.The results indicate that the accuracy of a daily GEOSAR DEM is generally much lower than what can be achieved with typical LEO synthetic aperture radar(SAR)sensors;therefore,it is important to develop techniques to mitigate the effects of errors in GEOSAR DEM generation. | Zefa Yang Qingjun Zhang Xiaoli Ding Wu Chen | 2020 | Engineering2020，6，8： | 5 |
| 5 | A multi-institutional retrospective study of hyperthermic plus intravesical chemotherapy versus intravesical chemotherapy treatment alone in intermediate and high risk nonmuscle-invasive bladder cancer显示文摘Objective:To compare the efficacy and safety of hyperthermic intravesical chemotherapy(HIVEC)and intravesical chemotherapy(IVEC)in patients with intermediate and high risk nonmuscle-invasive bladder cancer(NMIBC)after transurethral resection.Methods:We included 560 patients diagnosed with primary or recurrent NMIBC between April 2009 and December 2015 at 1 of 6 tertiary centers.We matched 364 intermediate or high risk cases and divided them into 2 groups:the HIVEC+IVEC group[chemohyperthermia(CHT)composed of 3 consecutive sessions followed by intravesical instillation without hyperthermia]and the IVEC group(intravesical instillation without hyperthermia).The data were recorded in the database.The primary endpoint was 2-year recurrence-free survival(RFS)in all NMIBC patients(n=364),whereas the secondary endpoints were the assessment of radical cystectomy(RC)and 5-year overall survival(OS).Results:There was a significant difference in the 2-year RFS between the two groups in all patients(n=364;HIVEC+IVEC:82.42%vs.IVEC:74.18%,P=0.038).Compared with the IVEC group,the HIVEC+IVEC group had a lower incidence of RC(P=0.0274).However,the 5-year OS was the same between the 2 groups(P=0.1434).Adverse events(AEs)occurred in 32.7%of all patients,but none of the events was serious(grades 3–4).No difference in the incidence or severity of AEs between each treatment modality was observed.Conclusions:This retrospective study showed that HIVEC+IVEC had a higher 2-year RFS and a lower incidence of RC than IVEC therapy in intermediate and high risk NMIBC patients.Both treatments were well-tolerated in a similar manner. | Qiang Ruan Degang Ding Bin Wang Chaohong He Xuequn Ren Zhenhua Feng Zhigang Pang Jin Wang Xiangliang Zhang Hongsheng Tang Jiahong Wang Qingjun He Ziying Lei Quanxing Liao Jiali Luo Shuzhong Cui | 2021 | Cancer Biology & Medicine2021，18，1： | 4 |
| 6 | Hot Mixing Behavior and Curing Process of Epoxy Asphalt显示文摘A new hot mixed epoxy asphalt system was developed. The reaction process of epoxy resin was characterized by Fourier transform infrared spectroscopy (FTIR). The viscosity was investigated by Brinell viscometer when epoxy resin was mixed with asphalt. The glass transition temperature (Tg), homogeneity, thermal stability and viscoelasticity of epoxy asphalt were analyzed by differential scanning calorimetry (DSC), metallographic microscope, thermogravimetric (TG) and dynamic mechanical analysis (DMA). The results showed that the viscosity of epoxy resin modified asphalt reached 1000 mPa·s for more than 180 minutes at 180 ℃, while the best construction process is mixing at 180 ℃ for 2 hours and curing at 60 ℃ for 4 days. The particle size of asphalt is less than 50 μm. In addition, the mechanical properties of the materials are uniform within the specified pavement thickness. | 李华伟 WEI Wei ZHANG Chao XU Feifan LI Xin JING Peng 朱泉峣 DING Qingjun YAN Boxiang | 2020 | Journal of Wuhan University of Technology(Materials Science)2020，35，3： | 3 |
| 7 | Different Effects of Fly Ash and Slag on Anti-Rebar Corrosion Ability of Concrete with Chloride Ion显示文摘In this paper,we have studied the anti-rebar corrosion ability of high-strength concrete(HSC),which were made by one or two mixed fly ash and slag.The different effects of fly ash and slag on concrete anti-rebar corrosion ability were discussed in chloride ion-contaminated condition.The results indicate that the effects of slag on concrete anti-chloride ion penetration ability are more excellent than that of fly ash at the same content.When the content of fly ash is 10%,the corrosion-inhibition action is not obvious;when the content is higher than 25%,this effect is remarkable.Corrosion-inhibition action of slag is better than that of fly ash.Slag is not like fly ash that has obvious effect on anode curves Tafer slope,so its contribution to restraining rebar in concrete corrosion is the result of high concrete anti-chloride ion penetration ability and binding chloride ion.Their 'superimposition effect' can be realized only at reasonable content and proportion condition. | DING Qingjun GENG Jian HU Shuguang SUN Jiaying SUN Bingnan | 2009 | Wuhan University Journal of Natural Sciences2009，14，4： | 3 |
| 8 | Thermodynamic Stability of Sulfate Ions on Calcium Aluminosilicate Hydrate Microstructure显示文摘The thermodynamic stability of sulfate ions on synthesized calcium aluminosilicate hydrate (C-A-S-H) microstructure with different Ca/Si ratios and Al/Si ratios was investigated by XRD, SEM-EDS, 29Si and 27A1 nuclear magnetic resonance (NMR) and thermodynamic modeling. The results indicate that sulfate attack leads to both decalcification and dealumination for C-A-S-H gels, and the amount of corrosion products (gypsum and ettringite) decreased gradually with decreasing Ca/Si ratios of C-A-S-H. Sulfate ions can also promote the polymerization degree of C-A-S-H gels, improving its resistance to sulfate attack. Moreover, the 4-coordination aluminum (Al[4]) in C-A-S-H, 5-coordination aluminum (Al[5]), 6-ccordination aluminum (A1[6J) in TAH (third aluminum hydrate) and Al[6] in monosulfate or C-A-H (calcium aluminate hydrate) can be transformed into Al[6] in ettringite by sulfate attack. Furthermore, through thermodynamic calculation, the decrease of Ca/Si ratios and increase of Al/Si ratios can improve the thermodynamic stability of C-A-S-H gels under sulfate attack, which agrees well with the experiment results. | 胡晨光 DING Qingjun WANG Huan FENG Xiaoxin | 2019 | Journal of Wuhan University of Technology(Materials Science)2019，34，3： | 2 |
| 9 | Effect of fine steel slag powder on the early hydration process of portland cement显示文摘 | Hu Shuguang Ph D He Yongjia Lu Linnu Ding Qingjun | 2006 | Journal of Wuhan University of Technology - Mater Sci Ed2006，，1： | 1 |
| 10 | Influence of Polyepoxysuccinic Acid on Solid Phase Products in Portland Cement Pastes显示文摘The influence of polyepoxysuccinic acid(PESA)on the solid phase products in hydrated Portland cement pastes was investigated by isothermal calorimetry,X-ray diffraction(XRD),^(29)Si and ^(27)Al nuclear magnetic resonance(NMR).The results indicated that PESA bonds Ca^(2+)ions in pore solution to prevent portlandite formation,and also combines with Ca^(2+)ions on the surface of silicate minerals to prolong the control time of phase boundary reaction process,leading to the retardation of silicate mineral hydration.Meanwhile,the interlayer Ca^(2+)ions in Jennite-like structure bridging PESA and C-S-H gels prevent silicate tetrahedron and aluminum tetrahedron from occupying the sites of bridging silicate tetrahedron,which causes the main existence of dimer in C-S-H structure,deceases the degree of Al^(3+)substituting for Si^(4+)and promotes the transformation from 4-coordination aluminum to 6-coordination aluminum.Furthermore,the-Ca^+chelating group from reacting PESA with Ca^(2+)ions combines easily with SO_4^(2-)ions,resulting in transformation from ettringite,AFm to TAH(Third aluminum hydrate).However,with the higher addition of PESA,it will bridge the excess PESA by Ca^(2+)ions to form a new chelate with ladder-shaped double chains structure,which not only reduces the amount of PESA bonding Ca^(2+)ions,but also decreases its solidifying capability for SO_4^(2-)ions,leading to the transformation from TAH to AFm or ettringite.Meanwhile,at later hydration,the inhibition effect of PESA on cement hydration is weakened,and the transformation degree from TAH to AFm is higher than that to AFt with the addition of PESA. | 胡晨光 WANG Xiaoyan BAI Ruiying LIU Gang FENG Xiaoxin DING Qingjun | 2018 | Journal of Wuhan University of Technology(Materials Science)2018，33，5： | 1 |
| 11 | Comparative study of tribological properties of insulated and conductive polyimide composites显示文摘Insulated polyimide(PI)composites filled with short glass fibers(SGF),polytetrafluoroethylene(PTFE),SiO2,and polyphenylene(PPL)are specially designed,prepared,and the tribological properties are systematically investigated with references to the special requirements for frictional materials used in ultrasonic motors.The hardness and thermal decomposition temperature of the insulated PI composites are comparable to that of conductive PI composites.However,these insulated materials present excellent friction and wear performance,especially under high loads and speeds.Scanning electron microscopy(SEM)analysis of the worn surface indicates that adhesive and fatigue wear dominate the wear mechanisms. | Jingfu SONG Yuanhao YU Gai ZHAO Jinhao QIU Qingjun DING | 2020 | Friction2020，8，3： | 1 |
| 12 | Preparation of reactive powder concrete using fly ash and steel slag powder显示文摘 | Yanzhou Peng Shuguang Hu Qingjun Ding | 2010 | Journal of Wuhan University of Technology - Mater Sci Ed2010，，2： | 1 |
| 13 | Fabrication of ionic polymer-metal composites (IPMCs) and robot design显示文摘 | Peng Hanmin Ding Qingjun Li Huafeng | 2009 | Frontiers of Mechanical Engineering in China2009，4，3： | 1 |
| 14 | Heterogeneous Nature of Calcium Silicate Hydrate(C-S-H) Gel:A Molecular Dynamics Study显示文摘Structure and mechanical properties of Calcium silicate hydrate (C-S-H) at a molecular level act as 'DNA' of cement-based construction materials.In order to understand loading resistance capability of C-S-H gel,research on molecular dynamics (MD) was carried out to simulate the uniaxial tension test on C-S-H model along x,y,and z directions.Due to the structure and dynamic differences of the layered structure,the C-S-H model demonstrates heterogeneous mechanical behavior.On an XY plane,the cohesive force can reach 4 GPa,which is mainly provided by the Ca-O and Si-O ionic-covalent bonds.The good plasticity of calcium silicate sheet is attributed to the silicate branch structure formation and the recovery role of interlayer calcium atoms.However,in z direction,C-S-H layers connected by the unstable H-bonds network,have the weakest tensile strength 2.2 GPa.This results in the brittle failure mode in z direction.The relatively low tensile strength and poor plasticity in z direction provides molecular insights into the tensile weakness of cement materials at macro-level. | JIN Shucheng LI Jinhui XU Wenyuan DING Qingjun | 2020 | Journal of Wuhan University of Technology(Materials Science)2020，35，2： | 1 |
| 15 | Effect of Corrosive Ions (Cl^-,SO4^2-,and Mg^2+) on the Nanostructure and Chloride Binding Property of C-A-S-H Gel显示文摘The nanostructure and chloride binding capacity evolution of C-A-S-H gel exposed to aggressive solutions were investigated,utilizing 29Si NMR,27Al NMR,SEM-EDS,and XRD techniques.The experimental results show that while Cl-ions show a smaller effect on the microstructure of C-A-S-H sample,and SO4^2-ions can react with C-A-S-H,resulting in decreasing Ca/Si and Al[4]/Si for the C-A-S-H gel (i e,decalcification and dealuminization).The presence of Mg^2+ ions can aggravate the decalcifying and dealuminizing effects of SO4^2-ions on the C-A-S-H.With decreasing Ca/Si ratio and aluminum substitution for the original C-A-S-H gel,the depolymerization degree of silicate tetrahedra increases and the calcium aluminosilicate skeleton strengthens.C-A-S-H gel with lower Ca/Si ratio and higher Al[4]/Si ratio shows gentler nanostructure evolution under chemical attack,i e,improving thermodynamic stability under chemical attack.Furthermore,the chloride binding capacity of C-A-S-H gel is decreased after the sulfate attack.Aluminum substitution can also help C-A-S-H gel resist the degraded chloride binding capacity induced by sulfate attack. | JIN Shucheng LIU Kai ZHANG Gaozhan SHI Hua DING Qingjun 徐文远 | 2020 | Journal of Wuhan University of Technology(Materials Science)2020，35，6： | 1 |
| 16 | Hydration Process of Cement-Based Materials by AC Impedance Method显示文摘AC impedance is a new method to study the changes of pore structure and the hydration degree during the hydration and hardening process of cement paste by the change of the electrochemical parameters. Employing AC impedance method, we studied the hydration and hardening process of cement paste with fly ash and slag, and analyzed the influence of different hydration age, water-binder ratio and mineral admixture on the impedance parameters. Moreover, we compared the results with those by the conventional porosity testing method and X-ray diffraction method. The results showed that AC impedance could be taken as a new technology in cement and concrete research. | 随春娥 李悦 DING Qingjun | 2015 | Journal of Wuhan University of Technology(Materials Science)2015，30，1： | 0 |
| 17 | Influence Mechanism of Curing Regimes on Interfacial Transition Zone of Lightweight Ultra-High Performance Concrete显示文摘This study aims to clarify the effects of curing regimes and lightweight aggregate(LWA)on the morphology, width and mechanical properties of the interfacial transition zone(ITZ) of ultra-high performance concrete(UHPC), and provide reference for the selection of lightweight ultra-high performance concrete(L-UHPC) curing regimes and the pre-wetting degree LWA. The results show that, under the three curing regimes(standard curing, steam curing and autoclaved curing), LWA is tightly bound to the matrix without obvious boundaries. ITZ width increases with the water absorption of LWA and decreases with increasing curing temperature. The ITZ microhardness is the highest when water absorption is 3%, and the microhardness value is more stable with the distance from LWA. Steam and autoclaved curing increase ITZ microhardness compared to standard curing. As LWA pre-wetting and curing temperatures increase, the degree of hydration at the ITZ increases, generating high-density CSH(HD CSH) and ultra-high-density CSH(UHD CSH), and reducing unhydrated particles in ITZ. ITZ micro-mechanical properties are optimized due to hydration products being denser. | 李洋 张高展 YANG Jun ZHANG Jian DING Qingjun ZHAO Mingyu | 2023 | Journal of Wuhan University of Technology(Materials Science)2023，38，3： | 0 |
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