有线电视网络光纤资源管理

介绍了有线网络光纤资源管理方法,光缆接续表的标注和光缆接续图的绘制方法,将光缆网络路由图和设备分布情况与基础地图相叠加的方法,光纤资源管理系统实现方法及其在实际中的应用.     

An All Hydrophilic Fluid Diode for Unidirectional Flow in Porous Systems

A fluid diode that allows fluid flow in one direction but blocks fluid flow in the opposite direction has wide applications including oil recovery, drug delivery, and lab‐on‐a‐chip microfluidics. Many studies are conducted to facilitate directional liquid motion on the solid surface or across thin porous layers. However, the self‐driven one‐way flow inside porous systems still remains a significant challenge. Here, a novel all‐hydrophilic fluid diode (AHFD) made of porous materials with asymmetric pores is reported, which allows capillary flow in a chosen direction. The direction‐dependent flow process and the breakthrough pressure are experimentally and theoretically examined. The proposed AHFD can have many potential applications such as functional protective clothing, microfluidic valve, and oil–water separator, and the idea can be extended to develop other all lyophilic fluid diodes such as oleophilic diode.     

Photoresponsive Fiber Array: Toward Mimicking the Collective Motion of Cilia for Transport Applications

Remote transport of material is an utmost useful, but challenging, property expanding the design possibilities of many applications such as microfluidics or robotics where species can be carried without interfering with its environment. Nature has solved the problem of transport in e.g., the respiratory system by a concerted motion of cilia. This study addresses a new method to fabricate an array of small parallel fibers acting as cilia placed side by side on a substrate. The fibers consist of a crosslinked liquid crystal main chain polymer functionalized with coreactant azobenzene molecules. The fibers bend toward a light source in a concerted manner. When placed in a liquid, the cooperative bending motion of the fibers creates a flow able to efficiently carry objects. The proposed fabrication process of the fibers is scalable to large area and requires an optimized rheology which is achieved by converting low molecular weight reactive liquid crystal acrylate monomers to oligomers using a multiplication of the monomeric units by the Michael addition reaction with dithiol. The oligomer properties and the elasticity of the fibers are adjusted by changing the thiol spacer leading to optimized manufacturing and maximized optical response.     

Carbon‐Nanotube–PDMS Composite Coatings on Optical Fibers for All‐Optical Ultrasound Imaging

Polymer–carbon nanotube composite coatings have properties that are desirable for a wide range of applications. However, fabrication of these coatings onto submillimeter structures with the efficient use of nanotubes has been challenging. Polydimethylsiloxane (PDMS)–carbon nanotube composite coatings are of particular interest for optical ultrasound transmission, which shows promise for biomedical imaging and therapeutic applications. In this study, methods for fabricating composite coatings comprising PDMS and multiwalled carbon nanotubes (MWCNTs) with submicrometer thickness are developed and used to coat the distal ends of optical fibers. These methods include creating a MWCNT organogel using two solvents, dip coating of this organogel, and subsequent overcoating with PDMS. These coated fibers are used as all‐optical ultrasound transmitters that achieve high ultrasound pressures (up to 21.5 MPa peak‐to‐peak) and broad frequency bandwidths (up to 39.8 MHz). Their clinical potential is demonstrated with all‐optical pulse‐echo ultrasound imaging of an aorta. The fabrication methods in this paper allow for the creation of thin, uniform carbon nanotube composites on miniature or temperature‐sensitive surfaces, to enable a wide range of advanced sensing capabilities.     

Extending transmission bandwidth of air-core photonic bandgap fibers

Air-core photonic bandgap fibers offer many unique properties and are critical to many emerging applications. A notable property is the high nonlinear threshold which provides a foundation for applications at high peak powers. The strong interaction of light and air is also essential for a number of emerging applications, especially those based on nonlinear interactions and spectroscopy. For many of those applications, much wider transmission bandwidths are desired to accommodate a wider tuning range or the large number of optical wavelengths involved. Presently, air-core photonic bandgap fibers have a cladding of hexagonal lattice. The densely packed geometry of hexagonal stacking does not allow large nodes in the cladding, which would provide a further increase of photonic bandgaps. On the other hand, a photonic cladding with a square lattice can potentially provide much larger nodes and consequently wider bandgap. In this work, the potentials of much wider bandgap with square lattice cladding is theoretically studied and experimentally demonstrated.     

Microstructure and grain growth of the matrix of SiCf/Ti–6Al–4V composites prepared by the consolidation of matrix-coated fibers in the β phase field

The microstructural characteristics in the matrix of SiC_f/Ti–6Al–4V composites prepared by consolidation of the matrix-coated fibers in the high-temperature β single-phase field were investigated using both experimental and modelling methods. Some of the critical microstructure features, like volume fraction of component phases, composition of matrix alloys and matrix morphology were systematically studied, providing valuable insight into the microstructural characteristics in the matrix of SiC_f/Ti–6Al–4V composites. In order to assist in understanding the grain growth occurred in the matrix during consolidation processing, a theoretical model was developed. Excellent agreement between theoretical and experimental results was achieved.     

服装用天然纤维材料的文化构成

分析我国服装材料发展缓慢及服装设计难出惊人之作的重要原因。从天然纤维等具体物质材料的产生和发展历史出发,说明服装材料应用与社会文化倾向的关系,探讨服装用纤维材料在社会不同时期的文化表达内容,描述了服装用纤维材料的文化构成,阐述服装设计与纤维材料文化的必然联系与相互制约性,强调了在设计、生产和选用服装材料时注重其文化内涵以创造时尚的重要性。     

Rheology of natural fibers thermoplastic compounds: Flow length and fiber distribution

The presented study investigates the flow length and the corresponding fiber content distribution in the injection‐moulded natural fiber reinforced thermoplastics and its relation to fiber type and processing parameters such as injection pressure, temperature, injection rate and mould tempering by increasing die temperature. In this research, polypropylene compounds with nominally 30 wt % hemp and sisal fibers are investigated. The influence of the injection pressure (500 and 1000 bar), melt temperature (180°C, 200°C, and 220°C), and die temperature (23°C and 80°C) on the fiber content distribution all over the sample is investigated. An increasing linear trend of fiber content along the spiral length is observed as an evidence of a fiber/polymer multiflow system. A pattern for fiber content distribution with respect to the fiber length along the injected spiral can be distinguished, where the longer fibers are usually found at the end of the injected part and the shorter fibers remain near mould entrance point. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39861.