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Mo S.-M.,General Research Institute for Nonferrous Metals, China | Zhang Z.-G.,Beijing New Building Materials Public Ltd Company | Li J.-D.,General Research Institute for Nonferrous Metals, China | Pan Y.-H.,General Research Institute for Nonferrous Metals, China | Wang C.-H.,General Research Institute for Nonferrous Metals, China
Yejin Fenxi/Metallurgical Analysis

0.10 g (accurate to 0.000 1 g) of analytical sample was weighted and transferred into microwave digestion tank. After adding 3 mL of hydrochloric acid, the microwave digestion machine was heated from room temperature to 120 ℃ (kept for 5 min) and then to 180 ℃ (kept for 15 min) for microwave digestion. The determination method of 13 rare earth impurities (La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu) in cerium fluoride by inductively coupled plasma mass spectrometry (ICP-MS) was established using 10 ng/mL of Cs solution as internal standard. The results showed that the linear range of 13 rare earth impurities was 1.0-100 ng/mL. The linear correlation coefficients were higher than 0.999 5.The detection limit of method was 0.002-0.050 μg/g. The proposed method was applied to the determination of La, Pr, Nd, Sm and Gd in cerium fluoride powder sample, and the found results were consistent with those obtained by inductively coupled plasma atomic emission spectrometry (ICP-AES). The proposed method was also used to analyze the 13 rare earth impurities in cerium fluoride powder sample. The relative standard deviations (RSD, n=7) were all less than 5.0%, and the recoveries of standard addition were between 95% and 105%. ©, 2015, Central Iron and Steel Research Institute. All right reserved. Source

Zhang J.,Tsinghua University | Li Q.-H.,Tsinghua University | Zhao J.-P.,Beijing New Building Materials Public Ltd Company
Jianzhu Cailiao Xuebao/Journal of Building Materials

The shrinkage and mechanical properties of fiber reinforced cement board made with extruded dewatering method and ordinary casting method were studied. It is found that the shrinkage of the extruded dewatering board is lower than that of ordinary casting board even if they have the same water to cement ratio. Meanwhile, the development of shrinkage with time is faster for the extruded dewatering board than that of the ordinary casting board. The processing method has little influence on the mechanical properties of the polypropylene(PP) fiber reinforced cement board, while it has some influence on the mechanical properties of the polyvinyl alcohol(PVA) fiber reinforced cement board. The mechanical properties, including both flexural strength and flexural ductility, of PVA fiber reinforced cement board are improved very much compared with those of PP fiber reinforced cement board even if the boards have the same fiber content. Source

Li Q.-H.,Tsinghua University | Zhang J.,Tsinghua University | Zhao J.-P.,Beijing New Building Materials Public Ltd Company
Gongcheng Lixue/Engineering Mechanics

Different fibers were used to study their influences on the properties of fiber reinforced cementitious composites boards and beams. It was found that polyvinyl alcohol (PVA) fibers reinforced extruded dewatering board presents multiple cracking and strain hardening performance under bending load, and therefore has a good ductility. While, polypropylene (PP) fiber reinforced cement board presents single cracking and strain softening. Wood fibers reinforced cement board presents brittleness failure under bending load. Compared with the normal concrete beam, the fiber reinforced cement-concrete composite beam demonstrates better strength and ductility. The thicker the fiber reinforced cement layer, the better the properties of the beam. Compared with PP fiber, the bending strength and the corresponded deflection of PVA fiber reinforced composite beam are higher, and when the thickness of the fiber reinforced cement layer reaches 50mm, the beam displays strain hardening. Source

Du H.,Beihua University | Chang J.,Beijing Forestry University | Ren X.,Beijing Forestry University | Li R.,Beijing Forestry University | Wang P.,Beijing New Building Materials Public Ltd Company
Wood Research

The aim of this work was to develop a pyrolysis process for polyphenols fraction bio-oil, produced by fast pof Larix gmelinii circulated-fluidized bed (SCFB). This paper is focused on the process examination and product analysis. A range of operating parameters, including temperature (T) from 500°C to 600°C in the SCFB, and particle size (d) from 0.2-0.3 mm to 0.9-1.2 mm, and feed rate (n) from 20 r · min-1 to 50 r · min-1, and gas flow (Q) from 15 m3·h-1 to 30 m3·h-1 in the SCFB was conducted to the effect on the content of phenolic compounds (COP) bio-oil derived from Larix gmelinii. determined that the order of the parameters to influence on the COP in bio-oil was T > d > n > Q. The temperature and particle size of the parameters played key roles in the process. The operating parameters for increasing the COP of bio-oil were determined, i.e. temperature 550°C, particle size 0.3-0.45 mm, feed rate 50 r · min-1 and gas flow 15 m3 · h-1. Source

Zhu Q.,University of Science and Technology of China | Zhu Q.,Beijing New Building Materials Public Ltd Company | Zhang Y.,University of Science and Technology of China | Lv F.,University of Science and Technology of China | And 3 more authors.
Journal of Hazardous Materials

Cuprous oxide is firstly created on acidized sepiolite (AS) by a simple deposition method for photocatalytic degradation of the red water produced from 2,4,6-trinitrotoluene (TNT) manufacturing. X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), ultraviolet-visible diffuse reflection absorptive spectroscopy (UV-vis/DRS), and Fourier transform infrared (FT-IR) spectroscopy are used to characterize the photocatalyst composites. Gas chromatography/mass spectrometry (GC/MS) is employed to determine the organic constituents in the red water. The results show that the cuprous oxide particles can be immobilized on the surface of the AS fibers and the structure of the AS is altered when cuprous oxide interacts with AS via chemical reactions besides physical adsorption. The AS improves the optical properties of cuprous oxide and red-shifts the band gap thereby enhancing the utilization of visible light. The Cu 2O/AS composites demonstrate excellent photocatalytic performance in the degradation of red water. 87.0% of red water can be photocatalytically degraded by Cu 2O/AS after illumined for 5h and a majority of organic components of red water except 1,3,5-trinitrobenzene were degraded according to GC-MS analysis. © 2011 Elsevier B.V.. Source

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