Applied Mechanics and Materials Vol. 707

Abstract: The information about influence of additives based on the sol of silicon acid to the structure formation of limy compositions is provided. It is shown, that with the introduction of additive Sol of silicon acid in the limy mixture the acceleration of set of plastic and mechanical durability is observed. It is established, that in the presence of additive sol of silicon acid, a decrease of amorphous phase and increase of the crystal phase are observed.

Abstract: Latent heat storage is one of the most efficient ways of storing thermal energy. Compared with other kinds of PCMs, solid-solid PCMs have obvious advantages and have drawn more attention from the public. This paper reviews previous work on solid-solid PCMs. The advantages and disadvantages, as well as the preparation of three kinds of solid-solid PCMs were discussed. The problems associated with the application of PCMs with regards to the material and the methods used to contain them are also discussed. It is clear that solid-solid PCMs are promising, but possess the disadvantages as long phase transition time, low thermal conductivity, complexity and high cost. Therefore, there still much to do for solid-solid PCMs towards practical application in the future.

Abstract: A series of samples which have different surface roughness made by 45 steel were treated by Ultrasonic Deep Rolling (UDR), influence of original surface roughness on UDR effects, such as surface profile, surface roughness and residual stress, were studied. Results shows that surface roughness was reduced substantially through UDR treating and lager the original surface roughness, larger surface roughness and surface residual stress induced by UDR treating.

Abstract: TiO₂-Graphene nanocomposites were prepared by a wet chemical method and characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis). The nanocomposite demonstrated nice photocatalytic activity for water reduction to produce hydrogen. The optimal graphene content was found to be 10 wt%, giving a Hydrogen-production rate of 13.2 mmol∙h^-1∙g^-1, which significantly exceeded the rate observed on pure TiO₂. This high photocatalytic H₂-production activity is due to the deposition of TiO₂ nanoparticles on graphene sheets, which act as an electron acceptor to efficiently separate the photogenerated charge carriers.

Abstract: The BaF₂: Ce³⁺, Yb³⁺ nanoparticles doped with different concentration were prepared by a hydrothermal method. The structure,morphology and photoluminescence properties were studied. In BaF₂: Ce³⁺, Yb³⁺ nanoparticles, a strong near infrared emissionat 900 – 1050 nm matching to energy of Si band gap of Si-based solar cells was observed under the excitation of 5d level of Ce³⁺. As a downconversion luminescent convertor, the kinds of materials have potential to be applied in front of Si-based solar cells to reduce thermalization loss and enhance conversion efficiency of solar cells.

Abstract: The optical functionalized YVO₄: Eu³⁺/MCM-41 mesoporous composites were prepared by hydrothermal method. The structure, morphology, luminescence properties and fluorescence dynamics were studied systemically. The compared studies of the luminescence properties of YVO₄: Eu³⁺/MCM-41 with YVO₄: Eu³⁺ nanocrystal were performed. The results show that the YVO₄: Eu³⁺/MCM-41 retains high ordered mesoporous structure of MCM-41. In YVO₄: Eu³⁺/MCM-41, the intrinsic excitation bands of Eu³⁺ disappears and the lifetimes of Eu³⁺ become short. The luminescent efficiency of YVO₄: Eu³⁺/MCM-41 is higher than ones of the YVO₄: Eu³⁺ nanocrystal.

Abstract: This paper mainly discuss the effect of beating on OCC pulp fiber morphology and paper physical Strength. After the treatment with PFI, the beating degree were ranged from 25 ° SR rises from 56 °SR, the fiber morphologies were greatly changed, and appeared splitting and brooming. Physical results showed that beating can improve strength properties of OCC pulp in the proper degree, 46°SR was the best result in this study.

Abstract: The alternating current scanning electrochemical microscopy (AC-SECM) is an important method to characterize the electrochemical activity of living cells. In this paper, we apply AC-SECM to measure the electrochemical activity of diatom biofilm. We find that the diatom biofilm presents insulating effect to decrease the current, when the electrode is close to the biofilm. The alternating current impedance of diatom biofilm is overall smaller than that of the bare glass. To investigate the possible effect of chemical stimulus on cellular activity, the diatoms were immersed into paeonol solution (100 μg/mL), and AC-SECM imaging experiments were conducted when immersion time reached 20 h, 25 h and 35 h. The AC measurements performed at high frequencies show that phase angle decreases over time, which preliminarily indicates that the cellular activity of diatoms is affected by paeonol.

Abstract: Most of studies on transcriptional regulation mainly focus on upstream regions of genes. More and more recent researches indicate that introns may have important biological functions in transcription regulation of genes. The characterization of words in DNA sequences can be facilitated by the sequences’ functions. Using U-score and Z-score statistic, respectively, we extracted some over-represented words in intron 1s of ribosomal protein genes. A majority of them are accordance with known transcriptional factor binding sites and are potential regulatory elements. And, the detected over-represented words are more likely to form wider potential sequences and are denser in intron 1s of RP genes. We speculate the properties of these words may be associated with the transcriptional regulation of RP genes.

Abstract: The ethanol concentration, solid-to-solvent ratio, extraction temperature and extraction time were optimized by using orthogonal array design, an ultrasonic-assisted extraction (UAE) method was formed for extracting total flavonoids from Cassia Seeds. The optimal conditions for total flavonoids preparation were found to be extracted at 55 °C for 40 min with 75% (v/v) ethanol and a solid-to-liquid ratio of 1:30 (g/mL). The UAE was proven more efficient than the conventional extraction (CE) technique, which could be considered a time-saving method. Therefore, the UAE could be a promising candidate for extracting phenolic phytochemicals from natural plants.