Hot stamping of an Al-Li alloy: a feasibility study

The feasibility of forming a third generation aluminium-lithium alloy (AA2060) into a complex shaped panel component, was studied by using an advanced forming technology called solution heat treatment, cold die forming and in-die quenching (HFQa) process. The main challenges using HFQ technology to form complex shaped AA2060 component was to find out optimum forming parameters, such as forming temperature, forming speed, lubrication condition and blank holding force. In this paper, the optimum forming temperature was mainly concerned. The flow stresses of AA2060 were obtained at different temperatures ranging from 350 to 520 °C at the strain rate of 2 s−1. The suitable temperature to achieve the adequate ductility was found at 470 °C. By forming the AA2060 blanks at the optimum forming temperature, experimental results exhibited the feasibility for forming complex-shaped AA2060 components. The formed components were analysed through strain measurements. The post-form mechanical properties of AA2060 were assessed using hardness and tensile tests

21 cm foreground removal using AI and frequency-difference technique

The deep learning technique has been employed in removing foreground contaminants from 21 cm intensity mapping, but its effectiveness is limited by the large dynamic range of the foreground amplitude. In this study, we develop a novel foreground removal technique grounded in U-Net networks. The essence of this technique lies in introducing an innovative data preprocessing step specifically, utilizing the temperature difference between neighboring frequency bands as input, which can substantially reduce the dynamic range of foreground amplitudes by approximately two orders of magnitude. This reduction proves to be highly advantageous for the U-Net foreground removal. We observe that the HI signal can be reliably recovered, as indicated by the cross-correlation power spectra showing unity agreement at the scale of $k < 0.3 h^{-1}$Mpc in the absence of instrumental effects. Moreover, accounting for the systematic beam effects, our reconstruction displays consistent auto-correlation and cross-correlation power spectrum ratios at the $1\sigma$ level across scales $k \lesssim 0.1 h^{-1}$Mpc, with only a 10% reduction observed in the cross-correlation power spectrum at $k\simeq0.2 h^{-1}$Mpc. The effects of redshift-space distortion are also reconstructed successfully, as evidenced by the quadrupole power spectra matching. In comparison, our method outperforms the traditional Principal Component Analysis method, which derived cross-correlation ratios are underestimated by around 75%. We simulated various white noise levels in the map and found that the mean cross-correlation ratio $\bar{R}_\mathrm{cross} \gtrsim 0.75$ when the level of the thermal noise is smaller than or equal to that of the HI signal. We conclude that the proposed frequency-difference technique can significantly enhance network performance by reducing the amplitude range of foregrounds and aiding in the prevention of HI loss.Comment: 18 pages, 16 figure

SOAP3-dp: Fast, Accurate and Sensitive GPU-based Short Read Aligner

To tackle the exponentially increasing throughput of Next-Generation Sequencing (NGS), most of the existing short-read aligners can be configured to favor speed in trade of accuracy and sensitivity. SOAP3-dp, through leveraging the computational power of both CPU and GPU with optimized algorithms, delivers high speed and sensitivity simultaneously. Compared with widely adopted aligners including BWA, Bowtie2, SeqAlto, GEM and GPU-based aligners including BarraCUDA and CUSHAW, SOAP3-dp is two to tens of times faster, while maintaining the highest sensitivity and lowest false discovery rate (FDR) on Illumina reads with different lengths. Transcending its predecessor SOAP3, which does not allow gapped alignment, SOAP3-dp by default tolerates alignment similarity as low as 60 percent. Real data evaluation using human genome demonstrates SOAP3-dp's power to enable more authentic variants and longer Indels to be discovered. Fosmid sequencing shows a 9.1 percent FDR on newly discovered deletions. SOAP3-dp natively supports BAM file format and provides a scoring scheme same as BWA, which enables it to be integrated into existing analysis pipelines. SOAP3-dp has been deployed on Amazon-EC2, NIH-Biowulf and Tianhe-1A.Comment: 21 pages, 6 figures, submitted to PLoS ONE, additional files available at "https://www.dropbox.com/sh/bhclhxpoiubh371/O5CO_CkXQE". Comments most welcom

Selection of reference genes for gene expression studies in ultraviolet B-irradiated human skin fibroblasts using quantitative real-time PCR

<p>Abstract</p> <p>Background</p> <p>Reference genes are frequently used to normalise mRNA levels between different samples. The expression level of these genes, however, may vary between tissues or cells and may change under certain circumstances. Cytoskeleton genes have served as multifunctional tools for experimental studies as reference genes. Our previous studies have demonstrated that the expression of vimentin, one cytoskeletal protein, was increased in ultraviolet B (UVB)-irradiated fibroblasts. Thus, we examined the expression of other cytoskeleton protein genes, <it>ACTB </it>(<it>actin, beta</it>), <it>TUBA1A </it>(<it>tubulin, alpha 1a</it>), and <it>TUBB1 </it>(<it>tubulin, beta 1</it>), in human dermal fibroblasts irradiated by UVB to determine which of these candidates were the most appropriate reference genes.</p> <p>Results</p> <p>Quantitative real-time PCR followed by analysis with the NormFinder and geNorm software programmes was performed. The initial screening of the expression patterns demonstrated that the expression of <it>VIM </it>was suppressed after UVB irradiation at doses ≥25 mJ/cm²and that the expression of <it>TUBA1A </it>was significantly reduced by UVB doses ≥75 mJ/cm²in cultured human dermal fibroblasts. The analysis of the experimental data revealed <it>ACTB </it>to be the most stably expressed gene, followed by <it>GAPDH </it>(<it>aglyceraldehyde-3-phosphate dehydrogenase</it>), under these experimental conditions. By contrast, <it>VIM </it>was found to be the least stable gene. The combination of <it>ACTB </it>and <it>TUBB1 </it>was revealed to be the gene pair that introduced the least systematic error into the data normalisation.</p> <p>Conclusion</p> <p>The data herein provide evidence that <it>ACTB </it>and <it>TUBB1 </it>are suitable reference genes in human skin fibroblasts irradiated by UVB, whereas <it>VIM </it>and <it>TUBA1A </it>are not and should therefore be excluded as reference genes in any gene expression studies involving UVB-irradiated human skin fibroblasts.</p

Correlated oxide Dirac semimetal in the extreme quantum limit

Quantum materials (QMs) with strong correlation and nontrivial topology are indispensable to next-generation information and computing technologies. Exploitation of topological band structure is an ideal starting point to realize correlated topological QMs. Here, we report that strain-induced symmetry modification in correlated oxide SrNbO3 thin films creates an emerging topological band structure. Dirac electrons in strained SrNbO3 films reveal ultrahigh mobility (mu(max) approximate to 100,000 cm(2)/Vs), exceptionally small effective mass (m* similar to 0.04m(e)), and nonzero Berry phase. Strained SrNbO3 films reach the extreme quantum limit, exhibiting a sign of fractional occupation of Landau levels and giant mass enhancement. Our results suggest that symmetry-modified SrNbO3 is a rare example of correlated oxide Dirac semimetals, in which strong correlation of Dirac electrons leads to the realization of a novel correlated topological QM

Hot stamping of an Al-Li alloy: A feasibility study

The feasibility of forming a third generation aluminium-lithium alloy (AA2060) into a complex shaped panel component, was studied by using an advanced forming technology called solution heat treatment, cold die forming and in-die quenching (HFQ*) process. The flow stresses of AA2060 were obtained at different temperatures ranging from 350 to 520 oC at the strain rate of 1 s−1. The suitable temperature to achieve the adequate ductility was found at 470 oC. By forming the AA2060 blanks at the optimum forming temperature, experimental results exhibited the feasibility for forming complex-shaped AA2060 components. The formed components were analysed through strain measurements. The post-form mechanical properties of AA2060 were assessed using hardness and tensile tests. * HFQ® is a registered trademark of Impression Technologies Ltd

Hot stamping of an Al-Li alloy: A feasibility study

The feasibility of forming a third generation aluminium-lithium alloy (AA2060) into a complex shaped panel component, was studied by using an advanced forming technology called solution heat treatment, cold die forming and in-die quenching (HFQ*) process. The flow stresses of AA2060 were obtained at different temperatures ranging from 350 to 520 oC at the strain rate of 1 s−1. The suitable temperature to achieve the adequate ductility was found at 470 oC. By forming the AA2060 blanks at the optimum forming temperature, experimental results exhibited the feasibility for forming complex-shaped AA2060 components. The formed components were analysed through strain measurements. The post-form mechanical properties of AA2060 were assessed using hardness and tensile tests. * HFQ® is a registered trademark of Impression Technologies Ltd

Development and psychometric assessment of Health Action Process Approach (HAPA) in terms of smoking cessation among Chinese smokers

Abstract The Health Action Process Approach (HAPA) is a two-stage (pre-intentional and post-intentional) behavioral change model that distinguishes between motivation and volition in behavior change process. This study aims to develop HAPA-based assessments for smoking cessation among current smokers. The HAPA-based measures were developed and the draft measures included nine constructs, namely, risk perception in smoking-induced cancer, risk perception in smoking-induced systemic disease, positive outcome expectancy, negative outcome expectancy, self-efficacy in quitting smoking, self-efficacy in maintaining, self-efficacy in re-initiating, quitting planning and coping planning in smoking cessation, with a total of 26 items. A cross-sectional survey was conducted in China in 2022. Principal Component Analysis was used for Exploratory Factor Analysis (EFA). Cronbach’s α coefficient was calculated to evaluate the internal consistency. Variables such as severity of smoking addiction were selected to evaluate the correlation between the HAPA scale and these variables. Of the 928 participants, 76.4% (709/928) were male and the median age was 35 years. Five factors were extracted by EFA. The factor loadings of each item were all greater than 0.60, and the cumulative variance contribution rate was 90.15%. The Cronbach’s α coefficient of each HAPA-based subscales was 0.929–0.986. The HAPA-based measurements are comprehensive, reliable and valid in the assessment of smokers’ smoking cessation cognition, which can be used to guide the design and implementation of intervention and the development of theory