Abstract: Electron trapping materials SrS:Eu2+,Sm3+ were prepared by hydrothermal method at 200 °C for 5 h. The phase structure, microstructure and optical properties were characterized by XRD, SEM, EDAX, PL, PSL, and TL, respectively. The sample was stimulated by a 980 nm infrared laser after exposing to the sun light, It can be seen that the PSL emission spectra was a band spectrum with one peak at 605 nm, and this emission was ascribed to characteristic 5d → 4f transition of Eu2+, and the photo stimulated luminescence phenomenon was observed.
Abstract: This paper discussed the experimental resuhs of exploiting brick materials with iron tailing materials in Tanshang area. Through preparation of iron tailing bricks, the technical flow and production proportion was obtained. The results show that a burning-and steam curing-free brick product with a compressive strength of 28.30 MPa and Flexural strength of 5.63 MPa as the following: iron tailing; fly ash; sand; CaO; gypsum; cement. And long-term properties of a burning-and steam curing-flee brick is also studied by experiments in this paper. Put forward a new technique of making materials with iron tailing. At the same time, the micro mechanism of iron tailing brick was also studied with X-Ray Diffraction (XRD) and Scanning Electron Microscope(SEM).
Abstract: A blue-emitting phosphor, NaBaPO4:Eu2+, was prepared by solution combustion synthesis method, and its luminescence properties were investigated in detail. It was found that NaBaPO4:Eu2+ could be efficiently excited by the UV-visible light of 230-420 nm and exhibited bright blue emission, which matched well with the emission wavelength of near-UV LED chips. NaBaPO4:Eu2+ showed high thermally stable luminescence compared to commercial phosphor YAG:Ce3+. With the increase of the temperature, the normalized emission intensity of NaBa0.98PO4:0.02Eu2+ decreased to 92.3% of the initial value at 423 K, and the emission band exhibited a little blue-shift.
Abstract: In this paper, research was focused on the synthesis of a new efficient coagulant, boron -containing poly-silicate zinc (PSZB).The effect of the SiO2 concentration, Zn/Si molar ratio, B/Si molar ratio, activation time on flocculation properties were examined in detail. And the optimal preparation conditions were determined. At the same time, the industrial wastewater and life wastewater were treated for the properties test. The experimental results showed that the flocculant had good stability and good effect. It is a kind of good performance of flocculants.
Abstract: A series of new Na3CaB5O10:Eu3+ phosphor was synthesized by a solid-state reaction method, and its luminescent properties were investigated. The phase formation of phosphors was confirmed by X-ray powder diffraction (XRD). The excitation spectra exhibited that the phosphors could be effectively excited by near ultraviolet (392 nm) and blue (464 nm) light, which perfectly match the emission wavelength of near-UV light-emitting diodes (LEDs). The emission spectra showed that two characteristic red emission lines peaking at 592 and 613 nm can be obtained upon 394 and 463 excitation with the chromaticity coordinates of (0.6347, 0.3649), which are due to 5D0- 7F1 and 5D0-7F2 transitions of Eu3+ ions. The effect of Eu3+ concentration on the emission spectrum of Na3CaB5O10:Eu3+ phosphor was studied. The results showed that the emission intensity increased with increasing Eu3+ concentration, and then decreased because of concentration quenching. The obtained results indicated that this phosphor could be a promising candidate for near-UV white LEDs.
Abstract: Erbium and ytterbium co-doped sodium yttrium fluoride (NaYF4:Er3+,Yb3+) was synthesized by combusting in home microwave oven directly. The structure and morphology of the sample was characterized by the X-ray diffraction (XRD) and scanning electron microscopy (SEM), and its upconversion luminescence properties were investigated in detail. Under 980nm semiconductor laser excitation, the color of upconversion luminescence of NaYF4:Er3+,Yb3+ was green and red, and its upconversion spectrum exhibited distinct emission peaks at 522, 543 and 652 nm, the emission appears yellow-orange to the naked eye. The law of luminescence intensity versus pump power proved that the intense green emission at 522 and 543 nm were from Er3+ (2H11/2 → 4I15/2 and 4S3/2 →4I15/2), and the weaker red emission at 652 nm was from Er3+ (4F9/2→4I15/2), which belong to the two photon process.
Abstract: A new fabrication method for VC-Fe surface cermets by cast-sintering has been developed in the study. SEM and XRD were used to examine the variation of structure of surface composites after casting and solidifying. It was confirmed that the VC particles reinforced surface composites can be in situ produced on the casting surface by the cast-sintering technology. The mechanism of quickly finishing V carbonized reacts and sinter compacting in block during casting was analyzed. The wear-resistance of VC particles reinforced surface composites was examined on a MM-200 wear-test machine.
Abstract: In this study, the added value resultant from the incorporation of pultrusion production waste into polymer based concretes was assessed. For this purpose, different types of thermoset composite scrap material, proceeding from GFRP pultrusion manufacturing process, were mechanical shredded and milled into a fibrous-powdered material. Resultant GFRP recyclates, with two different size gradings, were added to polyester based mortars as fine aggregate and filler replacements, at various load contents between 4% up to 12% in weight of total mass. Flexural and compressive loading capacities were evaluated and found better than those of unmodified polymer mortars. Obtained results highlight the high potential of recycled GFRP pultrusion waste materials as efficient and sustainable admixtures for concrete and mortar-polymer composites, constituting an emergent waste management solution.
Abstract: The high manganese steel composites were successfully developed by different processes. The connection of high manganese steel-ceramic, the microstructure and abrasion performance of the composites were researched by SEM, mainwhile the connection mechanism and wear mechanism were studied. The results show that the grains of the matrix are refined; the connection is fine; the connection mechanism is diffusional bond; The wear surface had relatively shallow gully; Typical TEM morphologies of super-high manganese steel was high density dislocation, deformation bands, twin.
Abstract: We employ density functional theory to investigate TiAl3/Al interfaces with the orientation of (001) Al//(001)TiAl3 by electronic structures, relaxed atomic geometries and adhesions. The preferable interfacial atomic structure is that wherein Al atoms continue on the natural stacking sequence of bulk TiAl3. Two types of TiAl3 (001) slabs, Ti-centered, all Al atoms, are adopted to compare interfacial energy, interfacial electronic structure. The calculated adhesion energies Wad of the two types of interface are very close, and are quantitatively in agreement with other calculated results of Al on the carbide and nitride, but much lower than the (111)Al[1 0]Al//(0001)TiB2[11 0]TiB2 adhesion energy. We have thoroughly characterized the electronic structure and determined that the metallic Al-3p and Ti-3d bonding constitute the primary interfacial bonding interaction.