聚变实验堆真空室壳体成型残余应力分析

为了了解聚变实验堆真空室壳体表面残余应力的分布以及退火工艺对残余应力的影响，通过模拟分析和实验检测两种方式对不锈钢316LN冷压曲面和热压曲面残余应力进行研究，获得退火前后曲面表面残余应力的大小，得到冷压曲面和热压曲面残余应力的分布以及退火工艺对残余应力分布的影响。研究结果为分析成型工艺提供数据支撑，对中国聚变工程实验堆真空室的研究与制造具有重要意义。     

Molecular phylogenetic study and expression analysis of ATP-binding cassette transporter gene family in Oryza sativa in response to salt stress

ATP-binding cassette (ABC) transporter is a large gene superfamily that utilizes the energy released from ATP hydrolysis for transporting myriad of substrates across the biological membranes. Although many investigations have been done on the structural and functional analysis of the ABC transporters in Oryza sativa, much less is known about molecular phylogenetic and global expression pattern of the complete ABC family in rice. In this study, we have carried out a comprehensive phylogenetic analysis constructing neighbor-joining and maximum-likelihood trees based on various statistical methods of different ABC protein subfamily of five plant lineages including Chlamydomonas reinhardtii (green algae), Physcomitrella patens (moss), Selaginella moellendorffii (lycophyte), Arabidopsis thaliana (dicot) and O. sativa (monocot) to explore the origin and evolutionary patterns of these ABC genes. We have identified several conserved motifs in nucleotide binding domain (NBD) of ABC proteins among all plant lineages during evolution. Amongst the different ABC protein subfamilies, ‘ABCE’ has not yet been identified in lower plant genomes (algae, moss and lycophytes). The result indicated that gene duplication and diversification process acted upon these genes as a major operative force creating new groups and subgroups and functional divergence during evolution. We have demonstrated that rice ABCI subfamily consists of only half size transporters that represented highly dynamic members showing maximum sequence variations among the other rice ABC subfamilies. The evolutionary and the expression analysis contribute to a deep insight into the evolution and diversity of rice ABC proteins and their roles in response to salt stress that facilitate our further understanding on rice ABC transporters.     

Protective activity of an anthocyanin-rich extract from bilberries and blackcurrants on acute acetaminophen-induced hepatotoxicity in rats

Acetaminophen (N-acetyl-p-aminophenol, APAP) overdosage can produce fatal centrilobular hepatic necrosis in humans. The present study attempted to investigate the protective effect of an anthocyanin-rich extract from bilberries and blackcurrants (AE) against APAP-induced acute hepatic damage in rats. Treatment with AE normalised blood activities of glutamate oxaloacetate and glutamate pyruvate transaminase and prevented APAP-induced plasmatic and tissutal alterations in biomarkers of oxidative stress, probably due to various bioproperties of the components of the extract.     

The first principles investigation of ferrite magnetic response with mismatch stress

The quasi-ferrite model is proposed and an appropriate PBE exchange functional with the spin density functional theory(SDFT) is selected for the calculation of the relation between magnetic moment and residual stress in ferrite using a quantum mechanics code. The relationship between ferrite magnetism and the carbon content is determined,and then a ferrite interstitial solid solution(ISS) model in a low carbon concentration state is replaced with an α- Fe model in the case of majority magnetic calculation. The band structure of the loaded-Fe is compared with that of the unloaded α-Fe. The comparison shows that the energy of Fe atomic 3d orbital changes a little,while the energy of electron orbital of iron core below 3d almost keeps unchanged. The relationship between the magnetic moment and the stress appears intermittent due to the Bragg total reflection. The change in the magnetic moment due to lattice mismatch is much larger than that caused by mechanical loading.     

几种吊钩中的力学问题探析

对吊装机械中使用的几种吊钩在吊装重物时的受力情况进行分析和比较,说明了各自的特点及其应用.     

Proposition of a compensated pixelwise calibration for photonic infrared cameras and comparison to classic calibration procedures: Case of thermoelastic stress analysis

In this paper, we propose a compensated pixelwise calibration that integrates the effects of the camera housing temperature. The results of this calibration are compared on black body images to classic two points Non Uniformity Correction based calibrations, compensated or not. It is shown that the proposed approach leads to a significant improvement in the thermal resolution with a reduction in the mean error as well as the standard deviation. The approach is finally challenged on a real case measurement focusing on thermoelasticity. The gain in terms of accuracy measurement is highlighted by comparing the proposed calibration to classic calibrations and the scope of interest of this new calibration is discussed.     

Experiment on relationship between the magnetic gradient of low-carbon steel and its stress

In geomagnetic field, a series of tensile experiments on the low-carbon steel sticks were carried out. A special homemade detector was used to measure the magnetic gradient on the material surface. The results showed that the relationship between the magnetic gradient and the stress varied with different conditions of measurement. There was no obvious correlation between the magnetic gradient and the tensile stress if the sample remained on the material test machine. If the sample was taken off from the machine, the measured magnetic gradient was linear with the prior maximum stress. In Nanjing, PR China, a place of 32°N latitude, the slope of the linear relationship was about 67 (uT/m)/MPa. This offered a new method of non-destructive stress testing by measuring the magnetic gradient on the ferromagnetic component surface. The prior maximum applied stress of the sample could be tested by measuring the present surface magnetic gradient. Actually this phenomenon was the metal magnetic memory (MMM). The magnetic gradient near the stress concentration zone of the sample, the necking point, was much larger than other area. Thus, the hidden damage in the ferromagnetic component could be detected early by measuring the magnetic gradient distribution on its surface. In addition, the magnetic memory signal gradually weakened as the sample was taken off and laid aside. Therefore, it was effective for a given period of time to detect the stress or stress concentration based on the MMM testing.     

Stress–Strain Dependence of Segmented Polyurethanes and Polyurethane Ureas

The stress–strain dependences of segmented elastomers based on polyetherurethanes, polyesterurethane ureas, and polybutadieneurethane ureas were investigated. These dependences were adequately described using the generalized approach proposed earlier by the authors for amorphous elastomers. The experimental data obtained for four series of samples with chemical cross-linking confirmed an applicability of this approach for segmented elastomers. Unlike amorphous elastomers, the effective network density value was affected not only by the density of the chemical network, but the contribution of the network formed by the hard domains also needs be taken into account.     

一种面向高斯差分图的压缩感知目标跟踪算法

传统的压缩感知目标跟踪在目标纹理改变、比例缩放、光照变化剧烈时鲁棒性不足,本文提出一种面向高斯差分图的压缩感知目标跟踪算法。首先,构建原始图像的多尺度空间及其对应的图像高斯差分图,实现高斯差分图的特征提取并获取压缩感知的输入信号;然后,通过压缩降维,目标邻域遍历,参数更新等过程,计算出面向高斯差分图的后续帧的目标最优跟踪窗;最后,将跟踪窗投影到对应的原始图像上,完成面向视频流的目标跟踪。实验证明,高斯差分图像是单通道灰度图,相比较原始视频流的三通道彩色图,具有灰度取值范围小,数值低,结构简单,维数少等特点,增强了特征对纹理改变、比例缩放和光照变化的稳健性,且继承了原始算法的实时性。因此,与传统的压缩感知算法相比,本文算法能快速准确地实现复杂环境下的移动目标跟踪任务,具有更强的鲁棒性。