风轮不平衡载荷下超大型风电机组叶片颤振极限研究

以IEA Wind 15 MW参考风电机组为研究对象,基于非线性时域气弹耦合分析工具,研究风剪切、偏航入流、质量不平衡3种不平衡载荷单一或共同作用时,超大型风电机组叶片的颤振极限。结果表明,单一不平衡载荷作用时,风剪切和±15°以内的偏航角会增大临界颤振速度,而质量不平衡会降低临界颤振速度,且质量偏重时颤振速度下降更加明显。3种不平衡载荷共同作用时,临界颤振速度的最大值和最小值都出现在剪切系数为0.3时;最大值总是在偏航角为非负值时取得,最小值在偏航角为-20°时取得;质量不平衡对临界颤振速度的影响与其单一作用时的规律一致。因此,在进行气弹稳定性分析时,应考虑多种风轮不平衡载荷共同作用,尤其是叶片质量偏重和偏航角度为-20°时这种最不利的情况。

高压脉冲电场技术在食品加工及保藏中的应用

高压脉冲电场处理是一种对细胞具有电穿孔作用的非热加工新技术,在食品加工及保藏领域中具有广泛的应用前景。主要概述了高压脉冲电场技术在天然活性成分提取、杀菌、降解有害物、钝化酶、提高食品品质、农产品干燥等多个方面的研究进展。重点对该领域的相关文献进行了全面的综述,指出高压脉冲电场存在的问题,并对其应用前景进行了展望,为高压脉冲电场技术在产业化应用方面提供一定的参考。

Effective removal of brilliant green from aqueous solution with magnetic Fe_3O_4@SDBS@LDHs composites

The magnetic composite-materials(Fe3O4@SDBS@LDHs)were prepared by sodium dodecyl benzene sulfonate(SDBS)modified layered double hydroxides(SDBS@LDHs)with Fe3O4via co-precipitation method.The results of XRD,FT-IR and SEM/EDS indicated that the dispersibility of LDHs was improved,and the modification of SDBS took place on the surface of LDHs.The adsorption capacity of Fe3O4@SDBS@LDHs to brilliant green(BG)reaches329.1mg/g after the adsorption equilibrium.The thermodynamic parameters indicated that the adsorption process was endothermic and spontaneous,and the rate of a reaction increased with the raise of the reaction temperature.The Langmuir model was applicable for describing the sorption isotherms,indicating that the adsorption process is a monolayer adsorption.The results of kinetics study showed that adsorption fitted the pseudo-second order model well.The adsorbents still have good adsorption performance after four adsorption cycles.Moreover,the magnetic composite could be easily separated from aqueous solution.This indicated that Fe3O4@SDBS@LDHs can be considered as potential adsorbents in environmental applications for the removal of BG from aqueous solutions.

光培养条件对东北红豆杉外植体组培效果的影响

为了研究不同光培养条件对东北红豆杉外植体生长状况的影响,本文以带芽幼茎为试验材料,探讨了在光培养条件下,培养基中蔗糖的最佳用量,并采用正交试验设计分析得到适合东北红豆杉外植体生长的最佳光培养条件。试验结果表明:在光质为LED红蓝光(色比R∶B=3∶1),CO_(2)体积浓度为1500 mg/L,光照强度为12.5μmol·m^(-2)·s^(-1),光周期为10 h/d的环境下,培养基中蔗糖的最佳用量为10 g/L。此时,外植体芽萌动率和出愈率最高,芽萌动时间和初愈时间短,褐化率最低。正交试验得到适合东北红豆杉外植体生长的最佳光培养条件组合为:CO_(2)体积浓度为3000 mg/L+光照强度为37.5μmol·m^(-2)·s^(-1)+光周期为14 h/d。验证试验表明:该环境下外植体与对照组(无光)对比,染菌率降低了4.33%,芽萌动时间和初愈时间分别降低了2.33、3.75 d,芽萌动率和初愈率分别提高了16%、6.33%,愈伤组织鲜重增长倍数提高了0.35倍,紫杉醇含量提高了0.09 mg/L,为东北红豆杉在光培养环境条件下组织培养提供了理论基础和技术支持。