益生菌对生物体内持久性有机污染物和重金属的调节作用研究进展

持久性有机污染物和重金属的污染问题是全球关注的重要问题,其持续暴露会带来严重的生态风险和健康问题。这些污染物具有稳定的物理和化学性质,在生物体和环境中存在持久性、生物累积性、毒性以及较强的长距离迁移的能力而受到广泛关注。研究表明,持久性有机污染物和重金属在生物体内的积累会引起生物体的氧化应激和免疫损伤,破坏肠道微生物群的组成结构,打破肠道菌群的平衡。益生菌能够维持宿主肠道微生物群的平衡与稳定,有效提高生物体的抗氧化能力和免疫细胞的活性。益生菌已被证明能够减少宿主体内污染物的积累、提高宿主的免疫功能和调节肠道菌群的平衡,从而降低污染物引起的毒性作用。因此,本文综述了益生菌对生物体内持久性污染物和重金属毒性的调节作用,旨在为污染物的消减提供理论参考。     

基于HALCON的板料成形网格应变的测量

计算机视觉在网格应变测量领域的应用已成为研究热点,本实验是基于先进的图像处理软件HALCON,利用双目立体视觉原理,对印制有圆形网格的板料应变测量.首先采用印制有圆形标志点的平面标准标定板,对摄像机进行标定,获得摄像机的内外参数.采用基于NCC的匹配方法对左右图像特征点进行匹配,利用视差原理获得匹配点的三维坐标,对印制有圆形网格的板料进行三维重建.然后根据圆形网格变形后的椭圆长短轴的长度变化,计算得到真实应变,用OpenGL语言将应变可视化.     

通信技术在无功功率补偿装置中的研究与应用

论文主要介绍的是通信技术在电力系统中的重要应用。电力系统中,如何对配电网进行无功功率补偿,提高电网的功率因数,受到越来越多的关注。这样的背景下,设计了一种带有远程无线数据传输功能的无功功率补偿装置。同时文中还介绍了系统方案的选择,硬件和软件的设计与实现过程。     

Characteristics of cellulosic amine-crosslinked copolymer and its sorption properties for Cr(VI) from aqueous solutions

A new cellulosic amine-crosslinked copolymer was prepared after the amination reaction with cotton stalk peel (CSP). The physicochemical characteristics of amine-crosslinked cotton stalk peel (AC-CSP) and raw CSP were determined after the surface analysis (including specific surface area, micropore volume and SEM), zeta potential analysis and spectrum analysis (FTIR and Raman spectrum). The sorption properties of AC-CSP for Cr(VI) were evaluated in the static, column sorption and desorption tests. The surface characteristics indicated the absence of porous adsorption in the potential Cr(VI) sorption mechanism. Zeta potential and spectrum analysis of AC-CSP illustrated the involvement of amine groups in the Cr(VI) sorption process. The sorption capacity of AC-CSP for Cr(VI) was 129.0mg/g as comparison with 14.8 mg/g of raw CSP. Flow rate and influent Cr(VI) concentration were demonstrated as two influencial factors in the column sorption tests. NaCl was used as the eluent, and the desorption efficiencies during three successive cycles were 75.9%, 69.8% and 64.3%, respectively. In addition, the results of the static, column sorption and desorption tests illustrated the complicated interactions between Cr(VI) and AC-CSP including complexation and ion exchange mechanisms.     

空压缓冲罐静力学分析及其壁厚的优化设计

以有限单元法和优化设计的基本理论为基础,运用ANSYS软件对空压缓冲罐进行了静力学分析,计算出其轴向应力和和环向应力,并与理论解进行比较;在此基础上,对缓冲罐的壁厚进行优化.在满足强度条件下,以使其重量最小,显著提高了其经济效益.     

球域Bézier曲面的精确边界及其多项式逼近

为全面控制产品表面与理论曲面之间的偏差,引入球域Bézier曲面的定义,作为圆域Bézier曲线在三维空间的推广形式.根据经典微分几何中双参数曲面族的包络原理,运用球面参数坐标和Cramer法则,给出了球域Bézier曲面边界的精确数学显式表达式.依据函数逼近论中Legendre多项式的正交性,得到了采用多项式形式表示的球域Bézier曲面的精确边界的最佳平方逼近.进一步利用Legendre基与Bernstein基的转换公式,采用计算机辅助设计（CAD）系统中常用的Bézier形式表示球域Bézier曲面的近似边界.该算法表示简单,易于实现.通过具体实例对逼近效果进行演示与分析,结果表明该算法的逼近误差小,效果好.     

The doping effect of N substituting for different atoms in orthorhombic SrHfO<Subscript>3</Subscript>

The first-principles density-functional theory has been carried out to study the structural, electronic, and optical properties of N-doped orthorhombic SrHfO₃. The calculated results show the doping of N substituting for O is most favorable. When the doping of N substituting for Hf(Sr), the impurity energy level of N 2p states is introduced in the forbidden band. When the doping of N substituting for O1(O2), the width of the valence bands increases due to the presence of N 2p states in the top of valence bands. The doping of N resulting in red-shift has been studied by analysing the imaginary part of dielectric function e₂ (w) \varepsilon_{2} (\omega ) of N-doped orthorhombic SrHfO₃.     

Simulation of epitaxial growth on convex substrate using phase field crystal method

Phase field crystal （PFC） model is employed to simulate the process of growth of epitaxial layer on plane-convex substrate with a lattice mismatch and a small inclination angle. The variation of the systematic free energy, the total atomic number of the epitaxial layer, and the effect of the curvature and the angle of the substrate are analyzed. The results show that when the surface of the substrate is plane, the free energy increases with the increase of the substrate inclination angle, and also the total atomic number of the epitaxial layer increases; while the surface of the substrate is convex, the free energy decreases with the increase of substrate angle and so also the total atomic number of the epitaxial layer decrease. This is the reason that the frontier of surface of epitaxial layer changes from the step bunching to the hill-and-valley facet structure with the increasing of the inclination angle of convex substrate. These results are in good agreement with the other method results.     

二氧化钛相变研究现状

综述了二氧化钛由锐钛矿型向金红石型转变的影响因素,重点研究了温度调控与添加剂调控对二氧化钛锐钛矿型向金红石型转变的影响和作用机理。结果表明：温度调控能直接有效地促进二氧化钛锐钛矿型向金红石型转变;掺杂熔点低于TiO2的金属氧化物V2O5、SnO2等,离子半径与Ti4+半径相近的Fe3+、V4+、Ce4+等,以及体积小的低价阴离子Cl-、F-等都能促进TiO2由锐钛矿型向金红石型转变。