688 research outputs found

    Application of Poly (vinylbutyral) Nanocomposites in Environment Design

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    This text passed an adoption to totally mix a method to lead to make even PVB/SiO2 compound material into the nano SiO2 grain son in gather the PVB material.. With the UV-VIS, FT-IR, XRD, SEM etc. modern tested means token tiny view facial look, structure and optics function of material. Result enunciation:because the lead of the nano SiO2 grain son go into and make the compound material of the PVB/SiO2 have good ultraviolet rays to shield function; Meanwhile, the tenacity of material gets an obvious exaltation, it splits an elongation rate is 8 times than the for pure PVB material. Key words: nanocomposite; mixing process; nanometer silica; environment desig

    Surface Rebound of Relativistic Dislocations Directly and Efficiently Initiates Deformation Twinning

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    Under ultrahigh stresses (e.g., under high strain rates or in small-volume metals) deformation twinning (DT) initiates on a very short time scale, indicating strong spatial-temporal correlations in dislocation dynamics. Using atomistic simulations, here we demonstrate that surface rebound of relativistic dislocations directly and efficiently triggers DT under a wide range of laboratory experimental conditions. Because of its stronger temporal correlation, surface rebound sustained relay of partial dislocations is shown to be dominant over the conventional mechanism of thermally activated nucleation of twinning dislocations.National Science Foundation (U.S.) (Grant DMR-1410636

    A new regime for mechanical annealing and strong sample-size strengthening in body centred cubic molybdenum

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    Because of crystal symmetry, body centred cubic (BCC) metals have large differences in lattice friction between screw and edge dislocations, and manifest generally different mechanical behaviours from face centred cubic (FCC) metals. Although mechanical annealing (significant drop in stored dislocation density in response to applied stress) has been observed in FCC metals, it has not been observed in BCC metals so far. Here we show that significant mechanical annealing does occur in BCC Mo pillars, when their diameters decrease to hundreds of nanometers. In addition, there exists a critical diameter for focused ion beam milled pillars, below which the strengthening exponent increases dramatically, from ~0.3 to ~1. Thus, a new regime of size effects in BCC metals is discovered that converges to that of FCC metals, revealing deep connection in the dislocation dynamics of the two systems.National Natural Science Foundation (China) (Grant 50925104)National Natural Science Foundation (China) (Grant 50720145101)National Natural Science Foundation (China) (Grant 50831004)National Basic Research Program of China (973 Program) (Grant 2010CB631003)National Basic Research Program of China (973 Program) (Grant 2012CB619402)National Science Foundation (U.S.) (CMMI-0728069)National Science Foundation (U.S.) (DMR-1008104)National Science Foundation (U.S.) (DMR-1120901)United States. Air Force Office of Scientific Research (FA9550-08-1-0325

    Aldehyde Dehydrogenase 1 and Raf Kinase Inhibitor Protein Expression Defines the Proliferative Nature of Cervical Cancer Stem Cells

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    Purpose: To determine the differences in response following the use of aldehyde dehydrogenase 1 (ALDH1) and Raf kinase inhibitor protein (RKIP) as cervical cancer stem cell markers.Methods: To evaluate the cancer stem cell markers, a mouse model with low and high grade cervical cancer was developed and studied by histological examination. Immunohistochemical and Western blotting techniques were employed to study the expression profiles of ALDH1 and RKIP. The specificity of Sox2 that determines cancer stem cells served as control to validate ALDH1 and RKIP expressions.Results: Histological data helped to differentiate low from high grade cervical cancer. The results from immunohistochemistry show increased pattern of Sox2 expression as tumour progresses. Similarly, ALDH1, a protein that positively regulates stem cells shows mild expression in low grade cervical tumour, but positive signals are more amplified in an aggressive stage of tumour condition when compared with Sox2. The expression study with RKIP, a protein that negatively regulates stem cells, interestingly defines the higher expression in low grade cervical cancer to regulate the tumour, but shows little or no very mild expression in the aggressive stage of tumour. All the data obtained show a statistically significant value of p < 0.05. The results with Immunohistochemistry were further validated using the western blotting analysis and it also confirms the similar results.Conclusion: ALDH1 and RKIP marker in association correlation with Sox2 aids in defining the proliferative ability of cervical cancer stem cells and also to validate them in initial and advanced stages of cervical cancer.Keywords: Cervical cancer, ALDH1, BALB/c-nu/nu, HeLa cells, RKIP, Sox

    N′-(2-Hydr­oxy-5-chloro­benzyl­idene)-4-nitro­benzohydrazide methanol solvate

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    The title compound, C14H10ClN3O4·CH4O, was synthesized from the reaction of 5-chloro­salicylaldehyde with 4-nitro­benzohydrazide in methanol. The Schiff base mol­ecule is nearly planar, with a dihedral angle of 9.1 (3)° between the two benzene rings. The methanol solvent mol­ecules are linked to the Schiff base mol­ecules by N—H⋯O, O—H⋯N and O—H⋯O hydrogen bonds, forming chains running parallel to the a axis

    Catalytically efficient Ni-NiOₓ-Y₂O₃ interface for medium temperature water-gas shift reaction

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    The metal-support interfaces between metals and oxide supports have long been studied in catalytic applications, thanks to their significance in structural stability and efficient catalytic activity. The metal-rare earth oxide interface is particularly interesting because these early transition cations have high electrophilicity, and therefore good binding strength with Lewis basic molecules, such as H2O. Based on this feature, here we design a highly efficient composite Ni-Y2O3 catalyst, which forms abundant active Ni-NiOx-Y2O3 interfaces under the water-gas shift (WGS) reaction condition, achieving 140.6 μmolCO gcat-1 s-1 rate at 300 °C, which is the highest activity for Ni-based catalysts. A combination of theory and ex/in situ experimental study suggests that Y2O3 helps H2O dissociation at the Ni-NiOx-Y2O3 interfaces, promoting this rate limiting step in the WGS reaction. Construction of such new interfacial structure for molecules activation holds great promise in many catalytic systems
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