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Gao H.,Beijing Institute of Petrochemical Technology | Dong J.,Beijing University of Chemical Engineering | Dong J.,Beijing Institute of Technology | Zhang K.,Beijing Institute of Technology | Luan G.,Beijing Institute of Technology
Hanjie Xuebao/Transactions of the China Welding Institution | Year: 2014

Through the hierarchical method, microstructure and mechanical properties in different areas of the weld nugget zone for 30 mm thick 7A05-T6 aluminum alloy friction stir welding join have been studied. The results show that, the size of recrystallization grain in the near area of surface is largest. When the rotation speed is 360 r/min and the welding speed is 100 mm/min, for the area of T1 to T5, the tensile strength separately is 326, 354, 342, 334 and 307 MPa, the yield strength and elongation are also increased gradually. The fracture micrographs show that, there are a lot of mesh dimples in the fracture surface, and they are deeper on slicing T2 especially. The hardness profile is not central symmetric, and hardness value of top area is larger than that of lower area. Friction heat will decrease with the increase of thickness, and that is the reason why the performance decline at the middle and bottom of workpiece joint. Source

Liu X.,Tsinghua University | Chen J.,Tsinghua University | Zou J.,Beijing University of Chemical Engineering | Duan H.,Tsinghua University | And 3 more authors.
Journal of Applied Polymer Science | Year: 2011

The synthesis of quarternized ammonium cationic polyvinyl alcohol (QPVA+) is studied in this article. The effect of synthesis conditions on the degree of substitution (DS) is studied to acquire the optimal synthesis conditions. Polyelectrolyte and polyelectrolyte complex (PEC) membranes of QPVA+ and phosphatized anionic polyvinyl alcohol (PPVA-) are made by solution casting method. It is found that the flux of polyelectrolyte and PEC membrane, consisting of QPVA+ and PPVA- (1: 1 in molar ratio), is 403 g/m2 h, and its separation factor is 970 when the membrane is used in the pervaporation separation of ethanol/water. It is concluded that the hydrophilicity of the membrane and the rigidity of molecular chain segment are enhanced when the anionic and cationic groups are introduced in the PVA, and the membrane separation capability could be adjusted by changing polyelectrolyte material type and cation/anion mole ratio in the polyelectrolyte and PEC. © 2010 Wiley Periodicals, Inc. Source

Li M.,Beijing University of Chemical Engineering | Li M.,Inner Mongolia University of Science and Technology | Hu Y.,Beijing University of Chemical Engineering | Hu Y.,Inner Mongolia University of Science and Technology | And 5 more authors.
RSC Advances | Year: 2014

A polyelectrolyte controlled nonclassical crystallization method has been used to synthesize cerium oxide particles with tailored morphology. The results reveal that the as-prepared particles exhibit high specific surface area and enhanced oxygen storage capacity. This journal is © The Royal Society of Chemistry 2014. Source

Chen G.-H.,Beijing University of Chemical Engineering | Zhang A.-J.,Beijing University of Chemical Engineering
Journal of Beijing Institute of Technology (English Edition) | Year: 2011

To reduce the computing time of composite computer-generated holograms (CGHs) generation based upon the angular projection algorithm for holographic three-dimensional (3D) display, a grid-based holographic display (GHD) scheme was designed. The grid computing technology was applied to numerically process the different angular projections of an object in distributed-parallel manner to create the corresponding CGHs. The whole treatment of a projection was regarded as a job executed on the grid node machine. The number of jobs which were submitted to grid nodes, therefore, was equal to that of the projections of the object. A Condor-based grid testbed was constructed to verify the feasibility of the GHD scheme, and a graphical user interface (GUI) program and several service modules were developed for it. A 3D terrain model as an example was processed on the testbed. The result showed that the scheme was feasible and able to improve the execution efficiency greatly. © Copyright. Source

Liu J.,CAS Institute of Process Engineering | Liu J.,Beijing University of Chemical Engineering | Yu X.,CAS Institute of Process Engineering | Liu Q.,Beijing University of Chemical Engineering | And 12 more authors.
Applied Catalysis B: Environmental | Year: 2014

Flower-like branched TiO2 nanorod arrays (NRs) owning the surface anatase/rutile junctions on FTO substrates with operational diameter were successfully fabricated by a modified hydrothermal method. Transmission electron microscopy, Raman spectroscopy, field emission scanning electron microscopy, and X-ray diffraction revealed a unique flower-like ranched morphology, surface features, a crystal phase, and lattice constant of TiO2. Photoelectrochemical (PEC) measurements showed excellent photocatalytic properties of the flower-like branched TiO2 NRs. The surface phase formed between anatase and rutile TiO2 NRs which efficiently enhances the separation of photo-generated electron-hole pairs and accelerates the transport of charges is the key influence factor. The results suggest that the branched TiO2 NRs owning the surface anatase/rutile junctions are very promising platform to make highly efficient photoanodes for energy devices. © 2014 Elsevier B.V. Source

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