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Seismic response of concrete gravity dam reinforced with FRP sheets on dam surface

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Water Science and Engineering 2013年第4期6卷 409-422页

作者： Hong ZHONG na-li wang Gao liN Faculty of Infrastructure Engineering Dalian University of Technology ACRE Coking and Refractory Engineering Consulting Corporation MCC

This paper aims at exploring the effects of anti-seismic reinforcement with the fiber-reinforced polymer （FRP） material bonded to the dam surface in dam engineering. Time-history analysis was performed to simulate the seismic failure process of a gravity dam that was assumed to be reinforced at the locations of slope discontinuity at the downstream surface, part of the upstream face, and the dam heel. A damage model considering the influence of concrete heterogeneity was used to model the nonlinearity of concrete. A bond-slip model was applied to the interface between FRP and concrete, and the reinforcement mechanism was analyzed through the bond stress and the stress in FRP. The results of the crack pattern, displacement, and acceleration of the reinforced dam were compared with those of the original one. It is shown that FRP, as a reinforcement material, postpones the occurrence of cracks and slows the crack propagation, and that cracks emanating from the upstream surface and downstream surface are not connected, meaning that the reinforced dam can retain water-impounding function when subjected to the earthquake. Anti-seismic reinforcement with FRP is therefore beneficial to improving the seismic resistant capability of concrete dams.

关键词： Key words: FRP sheet reinforcement of concrete gravity dam bond behavior seismic damagesimulation time history analysis

Thermodynamic analysis of the Ti-Al-N system

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Journal of University of Science and Technology Beijing 2008年第4期15卷 420-424页

作者： Jie Gao Changrong li na wang Zhenmin Du School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

Motivated by the application of （Ti, Al）N alloy compound in the coating layer, the ternary phase diagram of Ti-Al-N was analyzed by the calculation of the phase diagram （CALPHAD） technique. The isothermal sections of the Ti-Al-N ternary system were constructed and compared with the literature experimental results. The thermodynamic parameters of the Ti-Al-N ternary system and the related Ti-N and Al-N binary systems were adopted from literatures, whereas, those of the Ti-Al binary from the literatures were adjusted according to both the ternary and the binary phase equilibria. The consistency between the calculated results and the experimental data shows that considering the ternary thermodynamic relationship, the adjustments to the thermodynamic parameters of the related binaries are necessary.

关键词： Ti-Al-N ternary system Ti-Al binary system phase diagram optimization thermodynamic analysis

Genetic structure and historical demography of Malus sieversii in the Yili Valley and the western mountains of the Junggar Basin, Xinjiang, China

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Journal of Arid Land 2015年第2期7卷 264-271页

作者： Hong Xiang ZHANG Ming li ZHANG li na wang Key Laboratory of Biogeography and Bioresource in Arid Land Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences Institute of Botany Chinese Academy of Sciences Central China Normal University

Malus sieversii, a wild progenitor of domesticated apple, is distributed in western Xinjiang of China, eastern part of Kazakhstan and Kyrgyzstan in Central Asia. To well understand the genetic structure and the his- torical demography of this important germplasm resource, we sampled 15 populations with 110 individuals of Malus sieversii from the Yili Valley and the western mountains of the Junggar Basin, Xinjiang, and sequenced two nrDna fragments for these 110 individuals. Meanwhile, we modeled and compared species distributions under the current and the Last Glacial Maximum climatic conditions. The results showed that populations of M. sieversfi from Xinjiang had low levels of genetic diversity and genetic differentiation. During the LGM period, populations of M. sieversfi had lost their northern distributions in the western mountains of the Junggar Basin. M. sieversfi has ex- perienced a demographic expansion from the south of the Yili Valley to the north of the western mountains of the Junggar Basin during the warm interglacial epochs. Due to the high sensibility of M. sieversii to disturbance, we proposed more attention should be paid to the M. sieversfi populations in the western mountains of the Junggar Basin.

关键词： Malus sieversii phylogeography LEAFY gene intron 1 species distribution modeling genetic diversity

Preparation and film-growing mechanism of hydrous zirconia coated on TiO_2

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International Journal of Minerals,Metallurgy and Materials 2010年第5期17卷 660-667页

作者： Jie li Ti-chang Sun Yong wang li-na wang Jing-kui Qu Tao Qi School of Civil and Environmental Engineering University of Science and Technology Beijing Beijing 100083 China national Engineering Laboratory for Hydrometallurgical Cleaner Production Technology Institute of Process Engineering Chinese Academy of SciencesBeijing 100190 China Key Laboratory of Green Process and Engineering Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China

To overcome the photochemical activity of rutile used as a pigment and improve its durability in application, hydrous zirconia-coated TiO2 was prepared by the precipitation method. High-resolution transmission electron microscope （HRTEM） and X-ray photoelectron spectroscopy （XPS） were used to characterize the morphology and surface structure of hydrous zirconia-coated TiO2. The ζ-potential and ultraviolet （UV） absorption of both coated and uncoated rutile were examined. The results show that hydrous zirconia can not only improve the durability but also raise the lightness. A suitable ZrO2 content of hydrous zirconia-coated TiO2 is about 1.0wt%, and a dense film on the surface of rutile can be formed with better pigmentary properties. Based on the thermodynamic analysis, the zirconia-coating process and the film growth mechanism were discussed.

关键词： coatings rutile zirconia materials preparation mechanism

Effect of Interfacial Adsorption on the Stability of Thin Polymer Films in a Solvent-induced Process

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Chinese Journal of Polymer Science 2021年第4期39卷 501-511,I0008页

作者： lin Xu Tong-Fei Shi li-Jia An Yu-Yuan Lu li-na wang Innovation Center for Textile Science and Technology Donghua UniversityShanghai201620China State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China Testing and Analysis Center Hebei Normal UniversityShijiazhuang 050024China

The stability of ultrathin polymer films plays a crucial role in their technological ***,we systematically investigated the influence of interfacial adsorption in physical aging and the stability of thin polymer films in the solvent-induced *** further identify the stability mechanism from the theory of thin film *** results show that the aging temperature and film thickness can strongly influence the stability of thin PS films in acetone *** aging can greatly improve the stability of thin polymer films when the aging temperature T_(aging1)>T_(g).A thinner PS film more quickly reaches a stable state via physical *** short aging time,the formation of the adsorbed layer can reduce the polar interaction;however,it slightly influences the stability of thin polymer films in the solvent-induced *** later aging stage,the conformational rearrangement of the polymer chains induced by the interfacial effect at the aging temperature Taging1 plays an important role in stabilizing the thin polymer ***,at T_(aging2)lightly influences the stability of the thin polymer *** formation of the adsorbed layer at Taging2 can reduce the short-range polar interaction of the thin film system and cannot suppress the instability of thin polymer films in the solvent-induced *** results provide further insight into the stable mechanism of thin polymer films in the solvent-induced process.

关键词： Thin polymer film Interfacial adsorption Dewetting Swelling process

Different Mechanisms of ε-M and α'-M Variant Selection and the Influencing Factors of ε-M Reversion During Dynamic Tension in TRIP Steel

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Acta Metallurgica Sinica(English Letters) 2018年第5期31卷 449-455页

作者： li-na wang Ping Yang Ting Jin Wei-Min Mao School of Materials Science and Engineering University of Science and Technology Beijing Department of Materials School of Tianjin University of Science and Technology Beijing

The variant selection of martensites（ε-M and α＇-M） and ε-M reversion in dynamic tensile high-manganese TRIP steel were investigated. α＇-M variant pairs with a zigzag morphology frequently formed, and the pairs of neighboring α＇-M variants were examined in terms of mechanical work and strain energy reduction. The occurrence of a primary α＇-M variant is determined by mechanical work, but high products of mechanical work and strain energy reduction are essential for secondary variant selection. In contrast to α＇-M variant pair selection, ε-M variant selection can be attributed to the highest mechanical work. During ε-M→α＇-M transformation, the mechanical work of ε-M reversion is higher than that of α＇-M variant, thereby implying that ε-M reversion in h110 icgrain is possible. e-M plate distribution also affects the feasibility of ε-M reversion.

关键词： TRIP-assisted steel Dynamic plastic deformation Martensitic transformation Variantselection Orientation relationship

Dynamic performance of a C/C composite finger seal in a tilting mode

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Chinese Journal of Aeronautics 2017年第4期30卷 1603-1614页

作者： Hailin ZHAO Guoding CHEN li'na wang Hua SU Fei LU School of Mechanical Engineering Northwestern Polytechnical University

The complex operating state of aeroengines has an impact on the performance of finger seals. However, little work has been focused on the issue and the dynamic performance of finger seals is also rarely studied. Therefore, a distributed mass equivalent model considering working conditions is proposed in this paper for solving the existing problems. The effects of the fiber bundle density and the preparation direction of the fiber bundle of a C/C composite on the dynamic performance of a finger seal are investigated in rotor tilt based on the proposed model. The difference between the C/C composite finger seal performances under the rotor precession and nutation tilt cases is also investigated. The results show that the fiber bundle density and the preparation direction of the fiber bundle have an influence on the dynamic performance of the finger seal as rotor tilt is considered, and the dynamic performance of the finger seal is different in the two kinds of tilting modes. In addition, a novel method for design of finger seals is presented based on the contact pressure between finger boots and the rotor. Finger seals with good leakage rates and low wear can be acquired in this method.

关键词： Aero-engine C/C composite Dynamic performance Finger seal Nutation tilt Precession tilt

Multi-Class Classification Methods of Cost-Conscious LS-SVM for Fault Diagnosis of Blast Furnace

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Journal of Iron and Steel Research International 2011年第10期18卷 17-23,33页

作者： liU li-mei wang An-na SHA Mo ZHAO Feng-yun College of Information Science and Engineering Northeastern University Shenyang 110819 Liaoning China

Aiming at the limitations of rapid fault diagnosis of blast furnace, a novel strategy based on cost-conscious least squares support vector machine （LS-SVM） is proposed to solve this problem. Firstly, modified discrete particle swarm optimization is applied to optimize the feature selection and the LS-SVM parameters. Secondly, cost-con- scious formula is presented for fitness function and it contains in detail training time, recognition accuracy and the feature selection. The CLS-SVM algorithm is presented to increase the performance of the LS-SVM classifier. The new method can select the best fault features in much shorter time and have fewer support vectbrs and better general- ization performance in the application of fault diagnosis of the blast furnace. Thirdly, a gradual change binary tree is established for blast furnace faults diagnosis. It is a multi-class classification method based on center-of-gravity formula distance of cluster. A gradual change classification percentage ia used to select sample randomly. The proposed new metbod raises the sped of diagnosis, optimizes the classifieation scraraey and has good generalization ability for fault diagnosis of the application of blast furnace.

关键词： blast furnace fault diagnosis eosc-conscious LS-SVM multi-class classification

Preparation of titanium dioxide from titania-rich slag by molten naOH method

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International Journal of Minerals,Metallurgy and Materials 2012年第3期19卷 205-211页

作者： Yan-fang Han Ti-changSun Jie li Tao Qi li-na wang Jing-kui Qu School of Civil and Environmental Engineering University of Science and Technology Beijing Beijing 100083 China national Engineering Laboratory for Hydrometallurgical Cleaner Production Technology Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China Key Laboratory of Green Process and Engineering Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China

Preparing titanium dioxide from titania-rich slag （TiO2 73wt%） by molten naOH method has been developed. The effects of temperature and reaction time on the titanium conversion were investigated. The results showed that temperature had significant influence on the titanium conversion as well as the structure of the product. About 92% of titanium in the titania-rich slag could be converted after reacting with naOH at 500℃ for 1 h. Metatitanic acid was formed through the steps of washing treatment, acid dissolution, and hydrolysis. Well-dispersed spherical titanium dioxide particles with an average size of 0.1-0.4μm can be obtained by calcination of metatitanic acid. In addition, the content of titanium dioxide in the product is up to 98.6wt%, which can be used as pigments after further treatment of coating and crushing.

关键词： slags titanium dioxide molten salt method pigments