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Cracking failure of butt-welded joint of 12Cr1MoV tube was comprehensively studied. Results show that both of initiation and propagation of the primary crack were circumferentially intergranular in...

Thermo-Span alloy is an oxidation resistant low thermal expansion superalloy and shows good mechanical properties, which has been used to fabricate components in gas turbine engine to control the clearance between static and rotating part, and thus improve the efficiency. Owing to the insufficient Cr, it was not applicable for this alloy to employ long homogenisation treatment at high temperature, and consequently, the primary Laves phase formed during the solidification process might be remained in this alloy. However, few studies were carried out on studying the role of primary Laves phase in this alloy. This paper studied the effects of primary Laves phase particles on the crack initiation and propagation during tensile test at room temperature, 650 and 750°C of the rolled bar made from casting Thermo-Span alloy. It was found that at room temperature, cracks were mainly related with the Laves phase larger than 5 μm and the Laves clusters. At 650°C, cracks were formed preferentially at large Lav...

In this paper, an efficient image deblurring algorithm is proposed. This algorithm restores the blurred image by incorporating a curvelet-based empirical Wiener filter with a spatial-based joint non-local means filter. Curvelets provide a multidirectional and multiscale decomposition that has been mathematically shown to represent distributed discontinuities such as edges better than traditional wavelets. Our method restores the image in the frequency domain to obtain a noisy result with minimal loss of image components, followed by an empirical Wiener filter in the curvelet domain to attenuate the leaked noise. Although the curvelet-based methods are efficient in edge-preserving image denoising, they are prone to producing edge ringing which relates to the structure of the underlying curvelet. In order to reduce the ringing, we develop an efficient joint non-local means filter by using the curvelet deblurring result. This filter could suppress the leaked noise while preserving image details. We compare our deblurring algorithm with a few competitive deblurring techniques in terms of improvement in signal-to-noise-ratio (ISNR) and visual quality.

In this paper, we propose a new deblurring algorithm, which is based on image reconstruction from incomplete measurements in Fourier domain. Our algorithm has two steps. Firstly, an initial estimator is obtained using Fourier regularised inverse operator. Secondly, parts of the estimator’s Fourier coefficients are saved, and the others are removed to suppress noise energy, and then the remaining coefficients are used to recover image based on the sparse constraints. This image reconstruction problem is an optimisation problem which is solved by a fast algorithm named split Bregman iteration. Our algorithm combines two different regularisation strategies efficiently by applying a selection matrix. The tests using images with different blurs and noise produce good results. The experiment shows that our method gives better performance than many other competitive deblurring methods.

Adsorption isotherms of 4 estrogenic compounds, estrone, 17β-estradiol, 17α-ethinylestradiol and Bisphenol A, using molecularly imprinted polymer were studied. The isotherms can be simulated by Langmuir model. According to the adsorption isotherms and the template's mass balance, an experimental concept, selective adsorption ratio, SAR, was proposed to assess how many template molecules extracted out of MIP could create selective binding sites. The SAR of the molecularly imprinted polymer was 74.3% for E2. This concept could be used to evaluate quantitatively the selective adsorption.

SummaryMicroarray studies conducted to determine the accumulation of organic acids in the fruit of 60Co-γ -irradiated melon (Cucumis melo var. ameri) resulted in the detection of 475 differentially expressed genes. Among these, 251 were up-regulated and 224 were down-regulated. This finding included an additional 62 up- and 33 down-regulated unknown (“no hit”) genes. Among the genes identified, 47 showed significant False Discovery Rates (FDR) of < 0.01 and substantial (≥ 2-fold) differential expression. The genes identified included those for the mitochondrial precursor of citrate synthase (CS), genes associated with plant defense responses, cell wall modification, plant hormone synthesis and signal transduction, and the structural constituents of ribosomes, as well as transcription and regulatory factors. The compositions and concentrations of organic acids and CS activities during pre- and post-irradiated fruit development were measured using HPLC and a UV-spectrophotometer. Comparative transcription p...

The radiation damage to a specimen in the chamber of electron microscopes has been studied extensively in the past few years. However, for the specific case of specimens with a core/shell structure, such as microcapsules and biological cells, there has been little experimentation devoted to understanding how the radiation may affect their mechanical properties. In the present work, single melamine formaldehyde (MF) microcapsules were imaged using an environmental electron microscope (ESEM) under both dry and wet modes under conditions of different accelerating voltages. The changes in the morphology (shape) were monitored as a function of radiation time. In addition, a newly developed ESEM based nanomanipulation technique was used to measure how the force imposed on single MF microcapsules for a given deformation changed with radiation time, in order to identify a time window within which the radiation damage to the microcapsules may be negligible in order to be able to study the mechanical proper...