An improved modal strain energy method for damage detection in offshore platform structures

The development of robust damage detection methods for offshore structures is crucial to prevent catastrophes caused by structural failures. In this research, we developed an Improved Modal Strain Energy (IMSE) method for detecting damage in offshore platform structures based on a traditional modal strain energy method (the Stubbs index method). The most significant difference from the Stubbs index method was the application of modal frequencies. The goal was to improve the robustness of the traditional method. To demonstrate the effectiveness and practicality of the proposed IMSE method, both numerical and experimental studies were conducted for different damage scenarios using a jacket platform structure. The results demonstrated the effectiveness of the IMSE method in damage location when only limited, spatially incomplete, and noise-polluted modal data is available. Comparative studies showed that the IMSE index outperformed the Stubbs index and exhibited stronger robustness, confirming the superiority of the proposed approach.     

A Solution Processable Flexible Transparent Conductive Graphene/PEDOT: PSS Film Fabricated by Spin and Blade Coating

Flexible transparent conductive films were made on PET substrates by spin and blade coating, using graphene sheets dispersed in PEDOT: PSS solution. Ultrasonic substrate vibration was used to improve microstructure and properties of the films. Comparing to the pristine PEDOT: PSS film, the sheet resistance is 3 to 4 orders of magnitude lower with the addition of graphene. The conductivity and reproducibility of the film are improved for two-layer films comparing to one-layer films, with a reduction in transparency. Films prepared with substrate vibration showed lower sheet resistance for one-layer films, as the size of dewetting areas is reduced. In addition, large-area flexible films with desirable conductivity and transmittance were successfully fabricated by blade coating, which is promising, as the process is low-cost, scalable and compatible with roll-to-roll manufacturing.     

基于经济效益的高速铁路列车开行方案评价及调整

高速铁路列车开行方案优劣直接影响高速铁路的市场经济效益,而列车开行方案评价是优化开行方案的基础.为优化运输组织、提高经济效益,从营运能力、盈利能力和服务能力3个方面构建高速铁路列车开行方案评价指标体系,引入后退法思想筛选指标,构建基于决策偏好的超效率DEA评价模型确定列车开行方案经济效益评分,利用投影原理构建基于投入要素限制的调整优化模型,优化调整DEA无效的列车开行方案.以京沪高速铁路为例,结果表明,该方法能较好地反映高速铁路列车开行方案资源利用和产出效率,能为高速铁路列车开行方案优化提供理论指导和决策依据.     

功能矫形前伸下颌对青春期大鼠咬肌TrkC表达的影响

目的探讨功能矫形前伸下颌对青春期大鼠咬肌酪氨酸激酶受体-C(tyrosine kinase receptor-C,TrkC)表达的影响。方法设立实验组与同步对照组,实验组大鼠佩戴功能矫治器,根据佩带周期分为实验3、7、14、21d组与正常同步对照组。采用免疫组织化学染色法及聚合酶链反应(PCR)检测大鼠咬肌TrkC及其mRNA的表达。结果与对照组相比,实验3、7d组,咬肌纤维TrkC免疫阳性染色与mRNA表达均无明显变化,而实验14、21d组TrkC免疫阳性染色明显强于同步对照组,TrkC基因表达亦明显高于对照组。结论功能矫形下颌前伸可致大鼠咬肌TrkC的表达发生改变,提示其参与了下颌前伸过程中咬肌适应性的改建活动。     

站内有车影响下的公交车自主停靠轨迹规划方法

针对公共交通环境下公交车的自动安全停靠问题,考虑与站台几何结构拟合度、站台内有车影响以及行驶连续性等安全约束条件,采用非线性约束优化函数计算连续曲率的进站轨迹,构建了公交车自主停靠轨迹规划模型,分别利用Sigmoid函数、三次样条插值、反正切函数及改进的反正切函数对公交车受前车制约下的停靠轨迹进行仿真分析.?实验结果显...     

新型空心方块斜坡堤结构在长江口深水航道治理工程中的应用

针对长江口N IIC-1区段特殊的工况和地质条件,采用了创新的空心方块斜坡堤结构。在满足抗浪稳定性要求的同时,利用空心块体自身及块体间的大空隙率减轻堤身自重应力,满足了地基承载力和堤身整体稳定性要求。开发了空心方块斜坡堤结构全套施工工艺。该堤段工程已顺利建成,并经受了台风浪的考验,使用效果良好。文章对这一新型结构诞生的背景、创新思路、开发及实践过程和工程效果作了简要介绍。     

整船碰撞非线性有限元仿真

笔者在国内首次利用非线性显式有限元方法对可变形的船首结构撞击可变形的船侧结构的全过程进行了动态模拟。本文通过对一艘40000t油船正撞30000t散货船船侧的数值仿真讨论了船舶碰撞数值仿真中所涉及的关键技术，给出了船舶碰撞仿真中提高计算效率、精确性和稳定性的原则和方法。     

关于目前建设单位项目管理的几点意见

以沪杭复线上一些工程建设项目的经验为基础，对目前建设单位搞好项目管理，指出下列６方面建议：（１）狠抓设计管理；（２）严格招、投标管理；（３）加强对合同的管理；（４）推行监理制度；（５）加强工程项目实施中的管理和验收转产工作；（６）加强基建管理，不断提高决策水平。     

安全综合检测车研究

本文介绍了安全综合检测车研究及其系统总框图；轨道状态检测，轮轨作用检测、弓网状态检测，通信信号检测四个子系统框图，安全综合检测车的计算机系统，安全综合检测车车辆技术参数。