Time filter

Source Type

Shao D.,Shijiazhuang University | Diao J.,Shijiazhuang University | Diao J.,Hebei Provincial Key Laboratory of Traffic Engineering Materials | Wang L.,Shijiazhuang University | Li L.,Shijiazhuang University
Journal of Polymer Engineering | Year: 2016

Silica fume was modified by a silane coupling agent (KH-550). The modified silica fume was further investigated to reinforce polyurethane (PU) composites. Unmodified and modified silica fume reinforced PU composites were prepared. Through the comparisons of Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) of unmodified and modified silica fume, the agglomerations of silica fume particles were effectively prevented as KH-550 was grafted. The compressive strength of the modified silica fume/PU composites was largely improved, because KH-550 could react with both silica fume and PU. Meanwhile, modified silica fume turned from hydrophilic to hydrophobic; a better dispersion was realized in the PU elastomers compared to the unmodified silica fume. The reinforcement effects were evaluated based on the results of a universal test machine in comparison with unmodified silica fume/PU composites. © 2016 Walter de Gruyter GmbH, Berlin/Boston.


Li Y.,Shijiazhuang University | Sun X.,Shijiazhuang University | Sun X.,Hebei Provincial Key Laboratory of Traffic Engineering Materials | Wang Y.,Shijiazhuang University | And 3 more authors.
Xiyou Jinshu/Chinese Journal of Rare Metals | Year: 2014

SiO2/TiO2 nanoparticles doped with the different contents of La were prepared by a flow-together neutralization process and characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) and UV-Vis. The effects of La content and calcination temperature on the photocatalytic activity were investigated by the photodegradation of methyl orange under ultraviolet light irradiation. The possible mechanism was also analyzed primarily. The results of FT-IR showed that the Ti-O-Si and Ti-O-La bonds were formed at the interface of the coating layer and TiO2 particles. The presence of La3+ in SiO2/TiO2 could inhibit the phase transformation from anatase to rutile, and enhance the thermal stability of TiO2. The XRD patterns indicated that the percentage of rutile phase was still very low in La-doped SiO2/TiO2 sample at 800°C, which was equal to that at 120°C. The TEM images demonstrated that La-doped SiO2/TiO2 nanoparticles had uniform size distribution and polished surface. The absorption spectra indicated an extension of light absorption into the visible light region for the as-prepared samples. Among all the samples, the largest red-shift could be found in La doped SiO2/TiO2 sample with 3.0%(mole fraction) La, the band gap reduced from 2.98 to 2.41 eV. The photodegradation results showed that the composite powder with 3.0% La had the best ability of photo-degradation. In comparison with pure TiO2 nanoparticles, the photodegradation efficiency could be improved to 55.1% after reaction for 20 min. In addition, the effect of calcination temperature on the photocatalytic activity of undoped TiO2 was obvious, the photodegradation efficiency decreased from 69% to 10.7% for 25 min with calcination temperature increasing from 120 to 800°C. For La-doped SiO2/TiO2 sample, the effect of calcination temperature was negligible.


Li Y.,Shijiazhuang University | Li Y.,Hebei Provincial Key Laboratory of Traffic Engineering Materials | Li C.,Shijiazhuang University | Zhang Z.,Shijiazhuang University | And 4 more authors.
Solid State Sciences | Year: 2014

Black bismuth oxychloride (BiOCl) with disordered surface structure has been prepared by a facile Fe reduction method and successfully used as a visible-light photocatalyst. XRD and FESEM results showed that black BiOCl has pure BiOCl phase with plate-like structure. The as-prepared black sample exhibited a broad absorption covered the whole visible light region. The high-resolution TEM images revealed the disordered surface structure, which could be the reason for the black color of BiOCl. The disordered surface was not only responsible for the visible-light absorption but also played a vital role in improving the separation of photo-induced electrons and holes. Methyl orange (MO) photocatalytic degradation experiments showed that the black sample exhibited higher photocatalytic activity than the pristine BiOCl under visible light irradiation. A possible formation mechanism of black BiOCl under Fe reduction was also proposed in our research work. © 2014 Elsevier Inc. All rights reserved.


Zhu H.,Hebei Provincial Key Laboratory of Traffic Engineering Materials | Zhu H.,Shijiazhuang University | Guo Z.,Hebei Provincial Key Laboratory of Traffic Engineering Materials | Guo Z.,Shijiazhuang University | And 5 more authors.
Hanjie Xuebao/Transactions of the China Welding Institution | Year: 2014

The FEM were founded to simulate the tensile behavior for butt joint of 6063 aluminum alloy by TIG welding basedon the software of ABAQUS. The effects of HAZ width and thickness on deformation of joint were studied. Andthen the equivalent model of aluminum alloy TIG welded joint was established, which was validated by the thin-walled tube with weld seam. The results indicate that the stress states of welded joints with uneven mechanical properties are complicated compared to the base material. There is sudden change of thetriaxial stress between the base material and HAZ and between the weld metal and HAZ. At the same time, the position of the maximum triaxialstress is transferredfrom the boundary between the base material and HAZ to the boundary between the weld metal and HAZ with the increase of the width of HAZ. The triaxialstress of the welded joint depends on both the thickness of specimen and the geometrical dimension of welded joint. The equivalent model of aluminum alloy welded joint is 20 mm in width. The fine model and the equivalent model for aluminum alloy thin-walled tube with welding line are in goodagreement.


Kong L.,Shijiazhuang University | Kong L.,Hebei Provincial Key Laboratory of Traffic Engineering Materials | Du Y.,Shijiazhuang University
Journal Wuhan University of Technology, Materials Science Edition | Year: 2015

The chemical and physical interactions in the interfacial transition zone (ITZ) between three different types of coarse aggregates (limestone, granite and basalt) and cement paste were investigated. The results show that all the aggregates are chemically active. Significant amounts of Ca2+, K+, and Na+ are absorbed by all the aggregates from the cement solution, granite and basalt also absorb significant amounts of OH− and release significant amounts of Si4+ into cement solution. The XRD, EDXA and pore structure results of the ITZ also show that more clinkers participate in the cement hydration in the ITZ of granite and basalt, and more hydrates are generated, hence resulting in a denser ITZ structure with a lower content of macropores. Although the limestone has the least activity, the connection between it and cement paste is tight, due to its rough surface and higher water absorption. Whereas the granite with smooth surface and lower water absorption has a loose connection with cement paste, many pores and cracks are visible, which is very detrimental to the concrete durability. © 2015, Wuhan University of Technology and Springer-Verlag Berlin Heidelberg.


Yang J.-H.,Shijiazhuang University | Yang J.-H.,Hebei Provincial Key Laboratory of Traffic Engineering Materials | Lou Q.-X.,Shijiazhuang University | Chen Y.-X.,Shijiazhuang University | And 2 more authors.
Synthetic Communications | Year: 2015

Friedel-Crafts reaction of indoles to aromatic α-ketimino esters was found to be catalyzed by camphorsulfonic acid with good yields (up to 98%) under ambient temperature. This process provides an efficient method for the synthesis of unnatural amino acid derivatives that bear quaternary carbon centers. © 2015 Copyright © Taylor & Francis Group, LLC.


Cui S.,Hebei Provincial Key Laboratory of Traffic Engineering Materials | Cui S.,Shijiazhuang University | Zhu H.,Hebei Provincial Key Laboratory of Traffic Engineering Materials | Zhu H.,Shijiazhuang University | And 4 more authors.
Hanjie Xuebao/Transactions of the China Welding Institution | Year: 2016

The butt welding was carried out on the thickness of 6mm 7075 aluminum alloy plate using FSW. The dual diameter samples were designed and tested by hydraulic servo testing machine. The deformation and failure process of FSW joints were observed by Olympus microscopes and scanning electron microscopic. The results show that double necking appears on the FSW joint during the process of loading. The necking firstly appears in the retreating side and then in the retreating side with the progress of loading. Microcracks initiate in the boundary of grain in the advancing side and retreating side by the coalescence of microvoids. With the increasing of strain, the amount of microvoids increases. When the strain is large enough, the microcracks appear due to coalescence of microvoids. The microcracks propagate towards the weld nugget zone along the 45° angle to the loading direction and result in fracture of FSW joints. The location of fracture lie in the weld nugget zone and the fracture mode of the joints is shear fracture mixed dimple. © 2016, Editorial Board of Transactions of the China Welding Institution, Magazine Agency Welding. All right reserved.


Duan S.,Shijiazhuang University | Duan S.,Hebei Provincial Key Laboratory of Traffic Engineering Materials | Qin C.,Shijiazhuang University | Qin C.,Hebei Provincial Key Laboratory of Traffic Engineering Materials | Li B.,Shijiazhuang University
Jinshu Rechuli/Heat Treatment of Metals | Year: 2015

Laser quenching was carried out on semi high speed steel(semi-HSS) 5Cr5MoSiV through synchronous powder feeding way with transverse flow CO2 laser processing machine, and microstructure and properties of the hardened layers were studied. The results indicate that the hardened layer of laser treated semi-HSS is divided into 4 regions as follow: fully quenched region, incomplete quenched region, the transition region and the substrate region. The microstructure of fully quenched region is martensite, retained austenite and a small amount of carbides. The hardness of the hardened layer increases by 1.5 times compared with the substrate. The change of laser power or scanning speed has a little influence on the surface hardness, but has significant influence on the depth of hardened layer. ©, 2015, Chinese Mechanical Engineering Society of Heat Treatment. All right reserved.


Du Y.,Shijiazhuang University | Du Y.,Hebei Provincial Key Laboratory of Traffic Engineering Materials | Zhang Y.,Shijiazhuang University | Wang J.,Shijiazhuang University | And 3 more authors.
Hecheng Shuzhi Ji Suliao/China Synthetic Resin and Plastics | Year: 2016

The novel non-toxic thermal stabilizer is prepared in this article by mixing process of gallic zinc/calcium(Zn/Ca) soap, gallic epoxy resin and o-cresol formaldehyde epoxy resin which are newly synthesized respectively. Evaluation of these compounds as thermal stabilizers for poly(vinyl chloride)(PVC) are measured. The results show that gallic Zn/Ca soap compound, gallic Zn/Ca soap mixing gallic epoxy resin compound and gallic Zn/Ca soap mixing o-cresol formaldehyde epoxy resin compound all exhibit greater thermal stability than that of traditional Zn/Ca stabilizers. Among which, the initial thermal degradation temperature of the sample containing gallic Zn/Ca soap mixing o-cresol formaldehyde epoxy resin compound (which has the best synergistic effect and thermally stable)rises by 41.6℃ than that of the sample containing traditional Zn/Ca stabilizers, meantime the static thermal stability time increases by 65%. © 2016, Research Institute of Beijing. All right reserved.


Si H.-Y.,Shijiazhuang University | Si H.-Y.,Hebei Provincial Key Laboratory of Traffic Engineering materials | Wang L.-J.,Lanzhou University | Feng W.-J.,Shijiazhuang University | And 5 more authors.
New Journal of Chemistry | Year: 2015

Novel dendron encapsulated conjugated organic molecular wire (Den-OPE)-CdSe quantum dot (QD) nanostructures have been designed. By tailoring the size of dendrimers, different amounts of Den-OPEs could be attached to CdSe, which forms different sizes of core-shell Den-OPE-CdSe composites. With an increase in the size of dendrimers, the emission intensity of CdSe QDs increased due to the higher Förster energy transfer (FRET) efficiency from the bigger size Den-OPEs to CdSe QDs. This journal is © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2015.

Loading Hebei Provincial Key Laboratory of Traffic Engineering Materials collaborators
Loading Hebei Provincial Key Laboratory of Traffic Engineering Materials collaborators