复线桥区航道的巷道效应分析

针对2座桥和3座桥构成的复线桥,利用数学模型,计算了不同桥间距和不同斜流交角情况下复线桥的水流流场,得到了修建复线桥后通航净宽的减小值,提出了计算净宽减小值的公式．分析结果表明,随着桥轴线法线方向与水流方向夹角的增大,通航净宽相应减小,需增大航宽;而桥梁间距与桥梁数目的增加,会使桥洞纵深长度增加,巷道效应更加明显,通航净宽也会增大．故桥洞长度及桥轴线法线方向与水流方向的夹角是影响巷道效应的主要因素．     

河北省海运业现状及发展建议

为找出河北省海运业发展的薄弱环节,破解制约河北省海运业发展的难题,促进河北省海运业长足发展,总结发展现状,分析存在的不足及主要影响因素,借鉴沿海海运发达省市的成功经验,指出加快推进海运业发展的路径和重点,提出发展建议:创新港航管理体制机制;加强政策资金扶持;优化金融服务;推进海运龙头企业率先发展;建设海运服务中心,集聚高端服务业,促进河北省海运业的长足发展。     

Review on composite structural health monitoring based on fiber Bragg grating sensing principle

Fiber Bragg grating (FBG) based sensors offer important advantages over traditional instrumentation with regards to real-time structural health monitoring (SHM) of composite materials and structures in recent years. FBG sensors, integrated into existing structures or embedded into new ones, have played a major role in assessing the safety and integrity of engineering structures. In this paper, a review on the latest research of the FBG-based SHM technique for composite field is presented. Firstly, the FBG sensing principle is briefly discussed and FBG and several other optical fiber sensors (OFSs) for SHM are performance-compared. Then, several examples of the use of FBG sensors in composite SHM are illustrated, including those from the field of cure monitoring, civil engineering, aviation, aerospace, marine and offshore platform. Finally, some existing problems are pointed out and some proposals for further researches are provided.