Advanced Materials Research Vols. 919-921

Abstract: Silica aerogel is a lightweight nanomaterial,which was originally applied to aerospace and military fields. With the optimization and improvement of silica aerogel production process, it has more applications in the field of energy saving, environmental protection, building material etc. This paper introduces some kinds of drying processes, some methods had been used in the production, while the others are under the consideration.

Abstract: A series of Tb³⁺-doped Li₂SrSiO₄ phosphors were prepared by high temperature solid state reaction. Effect of Tb³⁺-coped concentration on luminescence properties of Li₂SrSiO₄: Tb³⁺ phosphor was investigated by XRD, FTIR, PL and CEI measurements. The results showed that the unit cell constant of Li₂SrSiO₄:Tb³⁺ was reduced gradually with increasing Tb³⁺ concentration, and then the FTIR absorption intensity assigned to the stretch vibration of [SiO₄] and bend vibration of Si-O was decreased. The emission properties of Li₂SrSiO₄:Tb³⁺ phosphors are strongly dependent on the concentration of Tb³⁺. The stronger blue and weaker green emission were shown as adding 1% Tb³⁺ amount, while single bright green emission was presented in 20% Tb³⁺ contents. The corresponding CIE was observed from (0.192, 0.315) to (0.246, 0.599). The results showed that the luminescence properties of Li₂SrSiO₄:Tb³⁺ phosphor could meet various requirements by tuning the Tb³⁺-doped concentration.

Abstract: This article deals with study of minimum ignition temperature (MIT) of thermally modified spruce dust. Dust of several species of spruce was mixed, sieved, dried and subjected to Thermo-S temperature programme. Samples of dust (200 250 μm) were tested in Goldbert-Greenwald furnace apparatus for determination of the MIT of dust clouds. The influence of air pressure and sample weight to the MIT was studied. The results show that the MIT of thermally modified spruce dust gradually decreases as the sample weight and air pressure rise. The lowest value of MIT (470 °C) was measured, when the air pressure was 50 kPa and the sample weight 0,5 g. To reach even lower values of MIT (˂468 °C), the air pressure should gradually rise to approx. 42 46 kPa and the weight of dust sample should be approx. 0,46 0,53 g.

Abstract: The reinforcing and toughening effect of fiber reinforced concrete (FRC) are mainly under control of the interfacial bond strength in between of fiber and concrete, and the embedded length of fiber is one of the significant factors for interfacial bond strength. In this paper, pull-out numerical models based on single steel or polypropylene fiber have been studied with the fiber embedded length set as a variable and the influence of fiber embedded length on properties of single fiber pullout has, therefore, been analyzed. The results indicate that the longer the fiber embedded length, the larger the peak index and pull-out toughness of single fiber pull-out specimen could be reached, while the interfacial bond strength would decrease. The variation of fiber embedded length has only a little impact upon the damage process of pullout. Finally, the test results for specimen with the polypropylene fiber is more sensitive to the changes of embedded length compared those with steel fiber

Abstract: This paper studies the changes of composite binder basic properties caused by the addition of processed rice husk ash and blast furnace slag. Experimental results show that the fineness and pozzolanic activity of rice husk ash, slag in appropriate treatment are according to using standard. This novel composite binder becomes a little worse in availability performance, while its long-term strength is equivalent with normal cement.

Abstract: Wood flute back combination design [, experimental study to verify the practicality of wood back shocked. Development and application of wood back shocked, and replace the current wooden building construction template for the realization of environmental protection, energy conservation plays an important.

Abstract: Hyperbranched polymer was prepared by the polycondensation reaction via the A₂+B₄ route. The polymer was obtained by the reaction of 1,3-tetramethyl-1,3-bis (methyl-dicholorosilyl) ethyl disiloxane and di-tert-butyl adipate. The obtained polymer was soft solid. The polymer was characterized by ¹HNMR and IR spectroscopies. The¹H NMR and IR analysis proved the existence of the branched structures in the polymer.

Abstract: Eu (BA)3phen/PVP fluorescent nanofibers has been successfully fabricated based on PVP and europium complexes Eu (BA)3phen (BA = benzoic acid, phen = phenanthroline) via electrospinning technology. The as-prepared samples were characterized by field-emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS) and fluorescence spectroscopy (FS). The as-prepared Eu (BA)3phen/PVP nanofibers possess good fibrous morphology, smooth surface and narrow size distribution. The average diameter of nanofibers was about 250 nm. Under the excitation of 274-nm ultraviolet light, Eu (BA)3phen/PVP nanofibers exhibit red emissions of predominant peaks at 592 and 616nm, which are respectively attributed to the 5D0 →7F1 and 5D0→7F2 energy levels transitions of Eu3+ ions. The optimum mass percentage of Eu (BA)3phen to PVP is 15%. The fluorescent nanofibers are expected to apply in the fields of lasers, displays, amplifiers for optical communication, and medical imaging, etc.

Abstract: In this paper, an analysis of dark color fastness technology of polyesters or spandexs dark color fabric was done. Through the analysis, corresponding solutions were providing to enhancing the washing dark color fastness of polyesters or spandexs synthetic elastic fabric, how to surmount the dark color fastness difference in polyester or spandex, and result is poor in white dyes combination of polyesters or spandexs fine white finished fabric

Abstract: Adopting methyl allyl polyoxyethylene ether (TPEG) and unsaturated carboxylic acid throught REDOX system synthetize the polycarboxylic slump retaining admixture. Researching the impact factors of temperature,reaction time, acid alcohol ratio, dosage of initiator and molecular regulator to the polycarboxylic superplasticizer with slump retaining.In the circumstance of reaction temperature is 45°C, reaction time is 4 hours, acid alcohol ratio is 1:3.25,dosages of initiator and molecular regulator are 0.27% and 4% by weight.. Using infrared spectroscopy(IR) to characterize the molecular structure of polycarboxylic superplasticizer with slump retaining.