碳纤维布加固技术在某工程中的应用与分析

对碳纤维布在加固领域中的实际应用进行了介绍，结合工程实例，对在施工过程中如何优化施工工艺使其达到最佳设计加固效果进行了分析和探讨。     

钢筋混凝土的粘结强度理论

从能量原理出发，把钢筋混凝土看成为一种纤维增强复合材料，利用已有的实验回归公式，推导出了钢筋混凝土中钢筋与混凝土的脱开条件，给出了钢筋的拔出长度与拔出载荷的关系。     

A pseudo dual-cavity extrinsic fibre Fabry-Pérot interferometric vibrometer

An extrinsic fibre Fabry-Pérot interferometric (EFFPI) sensor for the measurement of velocity and displacement of a vibrating target has been demonstrated in this work. It operates on the principle of a pseudo-double cavity within a single interferometric or “sensing” arm which, in addition, provides a sense of direction of the moving target. This has been made possible by the introduction of a birefringent film positioned along the optical path between the sensing fibre end and the intended target. Two sets of interference signals are thus propagated and detected along one fibre arm to give robust and repeatable displacement–velocity information which have been found to be relatively independent on other external effects such as minor temperature changes. The sensor has been found to be capable of measuring the desired velocity information of an inclined target while typical excitation frequencies investigated ranged from 2 to 60 Hz. In addition, two sensor configurations have been studied, one based on “conventional” optical fibres at 780 nm while the other employs a polarisation-maintaining (PM) (PANDA type) fibre as the sensing arm and operates at 1310 nm.     

Fabrication process of open surfaces by robotic fibre placement

Composite materials are being used extensively in many industrial sectors. They offer excellent material properties compared to other structural materials available. However, the traditional fabrication process using manual hand lay-up is time consuming and labour intensive. Therefore, robotic fibre placement has been introduced to overcome these drawbacks. This approach may greatly reduce cycle time and manufacturing costs. This paper describes the overall strategy for the establishment of a flexible robotic fibre placement technique. The fabrication process planning of this new technique is presented. Three different types of fibre placement for open surfaces are discussed. These include simulation-based fibre path generation, fibre steering, and sensory-based contour following methodologies. The system architecture for the process control is also presented.     

高压架空线路应力测试的光纤传感系统

近年来，光栅传感器的应用得到了很大的发展。本文主要论述了光栅传感系统在电力领域的应用，采用波分／时分复合技术同时检测应力等其他参数。     

Modelling of Bird Strike on an Aircraft Wing Leading Edge Made from Fibre Metal Laminates – Part 2: Modelling of Impact with SPH Bird Model

Fibre Metal Laminates with layers of aluminium alloy and high strength glass fibre composite have been reported to possess excellent impact properties and be suitable for aircraft parts likely to be subjected to impacts such as runway debris or bird strikes. In a collaborative research project, aircraft wing leading edge structures with a glass-based FML skin have been designed, built, and subjected to bird strike tests that have been modelled with finite element analysis. In this second part of a two-part paper, a finite element model is developed for simulating the bird strike tests, using Smooth Particle Hydrodynamics (SPH) for modelling the bird and the material model developed in Part 1 of the paper for modelling the leading edge skin. The bird parameters are obtained from a system identification analysis of strikes on flat plates. Pre-test simulations correctly predicted that the bird did not penetrate the leading edge skin, and correctly forecast that one FML lay-up would deform more than the other. Post test simulations included a model of the structure supporting the test article, and the predicted loads transferred to the supporting structure were in good agreement with the experimental values. The SPH bird model showed no signs of instability and correctly modelled the break-up of the bird into particles. The rivets connecting the skin to the ribs were found to have a profound effect on the performance of the structure.     

微弯光纤传感器位移灵敏度研究

根据光纤模式耦合理论,光纤微弯时光纤中的传输光有光功率损耗,对微弯光纤传感器出射光强进行分析、测量,实验得出了位移灵敏度与微弯周期的关系,对应用微弯光纤组成分布式光纤测试系统的传感器具有重要意义。     

Photon scanning tunneling microscope,now and in the future

The concept of photon tunneling and the principle of the photon scanning tunneling microscope (PSTM) are described. The history of the PSTM and its development in China are reviewed. The principal problem in the recent development of the PSTM, together with its solution, is discussed. The distinguishing features and the future of the PSTM are described.     

Fibre-top atomic force microscope probe with optical near-field detection capabilities

We present a fibre-top probe fabricated by carving a tipped cantilever on an optical fibre, with the tip machined in correspondence of the fibre core. When approached to an optical prism illuminated under total internal reflection conditions, the tip of the cantilever detects the optical tunnelling signal, while the light coupled from the opposite end of the fibre measures the deflection of the cantilever. Our results suggest that fibre-top technology can be used for the development of a new generation of hybrid probes that can combine atomic force microscopy with scanning near field optical microscopy.     

Formation of oxidising species and their role in the viscosity loss of cereal beta-glucan extracts

The aim of this study was to determine the role of the formation of radicals and hydrogen peroxide in the viscosity loss of beta-glucan extracts from oat and barley. Radicals derived from endogenous H₂O₂ were formed spontaneously in all extracts. The decomposition of H₂O₂ by catalase had little or no effect on the viscosity, and the radical formation detected and measured by electron spin resonance (ESR) spectroscopy did not predict the shelf life of crude beta-glucan extracts. The addition of FeSO₄ accelerated the radical formation and viscosity loss, revealing the sensitivity of the extract viscosity towards catalysts for oxidation. Using 50% cadoxen in the extracts slowed down the viscosity loss in all extracts but still led to a 10–70% decrease of the initial viscosities during 4 weeks of storage. The results suggest that the viscosity loss may be a result from multiple mechanisms including chemical reactions during storage as well as aggregation and conformational changes.