Barmag:用于生产特种纱线的新型空气变形机

介绍了由Barmag公司研制的CATY新型空气变形机,可用于生产市场前景广泛的特种纱线。     

巴马格公司新一代变形机

MPS变形机是巴马格公司研发的用于丝束变形的新一代变形机。本文介绍了MPS新的设计思想及其应用的先进技术，设备的优点和适用性。     

用MPS变形机加工新型聚合物

描述了德国巴马格公司生产的MPS变形机的特点和应用.MPS变形机加工的一些新型聚合物--PTT和PLA,用可再生原料制造,也是可生物降解的.比较了PTT、PLA和各种常用纤维的性质.     

冷轧轧辊毛化技术

介绍了冷轧辊的４种毛化工艺和设备，综合分析对比了各种毛化工艺的优缺点，指出了冷轧毛辊毛化技术的发展趋势。     

Effects of processing variables on the Y2BaCuO5 size and magnetic properties of melt-processed YBa2Cu3Ox

Samples of YBa₂Cu₃O_x (123) with excess Y₂BaCuO₅ (211) in the molar ratio of 5:1 ( 123/211) were processed using the “solid liquid melt growth” (SLMG) technique. The effect of hold time above the peritectic on the magnetic properties was examined. Extended hold times above the peritectic during processing degrade the magnetic properties of SLMG processed 123. In SLMG 123, the very fine (>100 nm) 211 particles produced by this processing route are the primarymagnetic flux pinners. Extended hold periods reduce the number and/or coarsen the average size of these fine precipitates, resulting in a reduced magnetization. These results were compared to undoped Y123 processed by the more traditional melt texture growth (MTG). In MTG processing, extended hold times above the peritectic are found to result in improved magnetic behavior because of increased defect densities.     

模具表面球冠状微凸体形貌的激光加工

为了减少磨损,延长模具的使用寿命,在模具表面应用激光毛化处理。采用200W灯抽运Nd:YAG激光器,进行系统的激光毛化工艺试验,得出脉冲激光参量对模具表面微观形貌主要几何参量的影响规律,最终获得了预期的几何形貌。并分别测量和分析了毛化模具表面硬度和金相组织状况。结果表明,微凸体表面硬度比基体材料的表面硬度提高了30%~40%,提高了模具表面的耐磨性。     

多棱镜扫描分光多头激光毛化圆形毛化点分析

为了得到圆形的毛化点以改善传统单头激光毛化技术椭圆毛化点对轧制钢板的均匀性和力学性能的影响,提出了一种采用多棱镜扫描分光技术的多头激光毛化设备.在一定离焦量下,使得扫描过程中扫描光束所带来聚焦点非均匀移动可以与轧辊同步运行,理论上可以获得椭圆度(长短轴比)最小为1.0010957的近似圆形毛化点,并进行了生产实践.结果表明,理论分析计算与实际结果较为符合.通过对离焦量、扫描速度等毛化参量的控制,可以获得椭圆度根据特殊要求任意调整的毛化点,这为多头激光毛化技术的应用提供了指导.     

新型高速弹力丝机

对高速弹力丝机的最新技术进行了分析,对新技术、新结构的特点进行了总结。其技术发展理念适应当今节能降耗的趋势,具有很大潜力。     

Why self‐cleaning is important for solar thermal receivers?

Surface cleaning remains essential for the sustainable operation of high performance solar thermal receivers. Cleaning of optical surfaces, such as solar troughs and absorbers, requires energy intensive efforts because of the large surface area involvement such as those observed in solar farms. In addition, self‐cleaning of such surfaces becomes demanding because of lowering the cleaning costs, reducing the waste of resources, such as clean water, and minimizing the complication of the mechanical systems incorporated. Self‐cleaning of surfaces is associated with the low adhesion between the surface and the foreign particles; in which case, these particles can be removed easily from the surfaces in a cost‐effective way. The surface energy and contact area of the surface are two main important parameters influencing the particle adhesion on the surfaces. In this case, reducing the surface energy and forming micro/nano size pillars on the surface through texturing lower the particle adhesion on the surfaces significantly. In solar thermal energy harvesting applications, metallic or composite materials are used and texturing the surface remains challenging in terms of cost and precision of operation when conventional texturing methods are used. One of the methods to create surface texture consisting of micro/nano pillars is to use the laser beam ablation. This results in hierarchical distribution of surface texture with desired pillar heights1. In addition, laser surface texturing offers significant advantages over the conventional techniques. Some of these advantages include fast processing, precision of operation, and low cost. Although the laser processing involves with high temperature processing and thermally induced stresses remain important, the defects sites can be minimized via controlling the process parameters during the texturing. Introducing the assisting gas on the texturing surface enables to generate compounds such as oxide or nitride species, which lower the surface energy considerably. Consequently, investigation of laser texturing of solar energy materials while incorporating the assisting gas becomes essential. In the present perspective, the laser surface texturing of solar energy materials for thermal power applications is presented together with challenges and future perspectives. Specifically, the followings will be presented: (1) the texture characteristics of laser treated metallic and ceramic surfaces; (2) wetting state of the textured surface, and optical properties of textured surface in terms of absorption of the solar irradiation.     

Fabrication and tribological behaviors of corner-cube-like dimple arrays produced by laser surface texturing on medical needles

Micro-corner-cube-like dimples with various geometrical characteristics were fabricated on the surface of medical needles by laser surface texturing. The effects of geometric parameters of dimples on tribological behaviors were investigated by carrying out insertion tests. It was found that the textured surface with a dimple array increased the friction between the needle and phantom tissue because of stress concentrations near the edges. Furthermore, the drag increment rate increased with the increase of dimple size and circumferential number, while dimple depth had no significant effect on the friction. The minimal drag increment rate was achieved at a medium value of spacing. The geometric parameters of dimples could be varied to control area density that indirectly affect the friction behavior.