Superhydrophobicity on Micro-and Nanostructured Polyolefin Surfaces:an Experimental and Theoretical Study

1 Results Simultaneous micro-and nanostructuring was prepared on polyolefin surfaces by injection molding.The molds were made of electropolished aluminum foil where the micropatterns were structured with a custom made robot.Nanopatterns were subsequently created on the molds by oxidizing the aluminum surface electrochemically in polyprotic acid.The preparation technique allowed simultaneous control of the dimensions of the micro-and nanostructures.Structuring has a remarkable effect on the contact angle...     

蚊子复眼的防雾原理

蚊子复眼具有超疏水性和防雾功能,主要归功于蚊子复眼具有特殊的微、纳米分级结构。建立了复眼的微、纳米分级结构模型;并从界面疏水稳定性和热力学的角度进行了分析。界面稳定性分析表明蚊子眼微米和纳米级结构可抵抗的最大压力分别为67.2 k Pa和181 k Pa,能够有效地抵御外部雾滴的润湿。对于纳米尺度的小雾滴,由于受尺度和线张力的影响,类Wenzel状态的自由能高于类Cassie状态,因此在雾化过程中总是形成类Cassie状态,并进而形成Cassie状态。由于微米结构特别的半球形状和紧密排列,能够形成锥形疏水毛细管,这一锥形毛细管能够在雾滴长大过程中将雾滴从微结构内部排出,从而实现防雾。蚊子复眼上小尺度的纳米结构是实现防雾的基础和关键。     

Bio-manufacturing technology based on diatom micro- and nanostructure

Diatom frustules,considered as novel bio-functional materials,display a diversity of patterns and unique micro-and nanostructures which may be useful in many areas of application.Existing devices directly use the original structure of the biosilica frustules,limiting their function and structural scale.Current research into the shapes,materials and structural properties of frustules are considered;a series of frustule processing methods including structure processing,material modification,bonding and assembly techniques are reviewed and discussed.The aim is to improve the function of diatom frustules allowing them to meet the design requirements of different types of micro devices.In addition,the importance of the comprehensive use of diatom processing methods in device research is discussed using biosensors and solar cells as examples,and the potential of bio-manufacturing technology based on diatom frustules is examined.     

煤样的微细观裂纹损伤本构模型

基于对煤样受载变形过程中其内部微细观裂纹及变形损伤特征,通过选取合适的损伤参量,推导出单轴压缩下煤样的损伤本构模型,并得出材料常数A和n的表达式,进而解释其含义。实验结果表明实验曲线与理论曲线拟合度较高。     

糜子的大小孢子发生和雌配子体发育

1、大小孢子母细胞的减数分裂均为正常型:小孢子四分体有左右对称形、直列式和T形;大孢子四分体为直线排列。2、大孢子母细胞和四分大孢子的壁都有胼胝质沉积,胼胝质从大孢子母细胞的珠孔端壁开始积累,而后包围母细胞;消失的顺序是由合点端壁开始,再到侧壁,孢子之间的横壁最后消失。3、大小孢子母细胞减数分裂同时开始,同步进入粗绒期之后,雌性比雄性发育缓慢,以致二种母细胞的减数分裂不同时结束;在可育花中雌雄配子体是同时成熟的。4、成熟胚囊中反足细胞不立即进行细胞增殖,仍为三细胞;卵细胞无明显极性;助细胞极性明显。5、抽穗后花序基部不能完成减数分裂(未分化出花药唇片)的小穗是不生育小穗。     

内核/壳层微结构上应力诱导点阵花样研究

力学性能失配较大的多层结构自高温状态冷却收缩时会积聚很大的应力, 其应力失稳模式可表现为多种有序的应力花样, 可用于微纳米结构的自组装, 其中支撑面的几何结构对其上的应力分布点阵具有决定性的影响. 本文介绍了在球形和圆盘形内核/壳层上通过应力工程形成的三角铺排和菲波纳契螺旋花样, 探讨了以相互排斥粒子的最小能量构型为模型的特征应力花样与其支撑结构的几何之间关系的普适性, 并将此模型用于解释自然界中花叶序的多样性与特征不变性.