船员生理健康和心理健康作为船员健康体系框架的重要维度,对保障船舶安全、促进船员健康管理有着重要意义.其中,噪声是影响船员健康的重要因素,国际海事组织和中国船级社均对噪声防护制定了详细的标准.为从影响船员健康的角度论述船舶噪声机理,首先,对船舶噪声的类别进行细化,并对舱室噪声来源进行分析;其次,对比不同噪声仿真技术在船舶领域的应用,介绍船舶领域常见的统计能量分析法;最后,从噪声源、传播途径和噪声接受者等3个层面论述防治方法.研究结果表明,船体结构振动是舱室噪声的主要传播途径,船舶舱室结构的优化和阻尼材料的应用可以有效防治舱室噪声.

桥区水域通航环境复杂、事故多发,单一助航标志不足以保障船舶的安全.文中提出使用LED灯光引导系统建立桥区水域警示标识,使得船舶在进入桥区水域之前可以保持正确的船舶航路.首先确立导航方案,在光学软件Tracepro中使用菲涅耳透镜和矩形聚光镜构建光学元件,建立基于三种灯光颜色的LED视觉引导系统.根据设计光源的照射范围,在距离光源2 000 m处进行仿真模拟和实际光斑面积分析.仿真结果证明:光线实际水平发散角为5.2°,垂直发散角为14.3°,2 000 m处灯光清晰可辨,有效照射范围为1 500～2 000 m.结合大桥实例分析,此灯光引导系统可以辅助桥区助航标志,加强对过桥船舶的引导.

为解决弯曲航道桥梁通航宽度计算中桥墩紊流宽度计算精度不足的问题,依据实际弯曲航道串列桥墩及其水流条件,进行模型简化,采用DES中的SST k-ω模型,利用Fluent软件对弯曲航道桥区流场进行二维模拟.通过对比弯曲航道不同弯曲半径、桥墩直径,以及来流速度的流场研究桥墩紊流宽度的变化规律.仿真结果表明:弯曲航道凸岸侧桥墩紊流宽度大于凹岸侧桥墩紊流宽度,紊流宽度随着弯曲半径的增大而减小,随着桥墩直径及来流速度的增大而增大.进而拟合得出紊流宽度的计算公式.并通过工程实例验证了改进后的紊流宽度经验公式的准确性.

As human marine activities increases and marine economic industry develops, the harm and loss caused by marine biological fouling are becoming more prominent, mainly manifested in rasing CO2 emissions, affecting the safety of ships and underwater infrastructures, and hindering marine economic activities. In order to protect the marine ecological health, maintain the marine environment and reduce the impact of marine biological fouling on ship operation and marine safety, polyaniline CuO composite nano particles were synthesized by chemical method, and the toxicity of barnacle and the anti adhesion of diatom were tested in this paper. The toxicity experiment of barnacle confirmed that when the concentration of polyaniline CuO composite nanoparticles was 4 mg / L, the 24-hour mortality rate of barnacle reached 95%; The indoor hanging board experiment shows that the anti adhesion rate of polyaniline CuO composite nano acrylic coating to diatom is 89.5% after 75 days of indoor hanging board. This showed that polyaniline CuO composite nano has good anti biological fouling effect. At the same time, as an environment-friendly anti fouling agent, it has a good application prospect in anti marine biological fouling.

In the present paper, the spatio-temporal evolution of the vorticity field in the second wake instability, i.e. (pure) mode B is investigated to understand the wake vortex dynamics and sign relationships among the three vorticity components. Direct numerical simulation of the flow past a circular cylinder in the three-dimensional (3D) wake transition is performed, typically at a Reynolds number of 300. According to the time histories of fluid forces and frequency analysis, three different stages are identified. In the fully developed wake (FDW), the spanwise vortex core is almost two-dimensional, while the vortex braid is 3D due to the dominant streamwise interaction. However, streamwise and vertical vorticities owing to the intrinsic 3D instability are already generated first on cylinder surfaces early in the computational transition (CT). The evolution of additional vorticities with the same features as mode B shows that (pure) mode B could already be formed in the late CT. In the FDW, a special sign symmetry of these additional vorticities on the rear surface is observed, which is exactly opposite to that in (pure) mode B. Similarly, the two sign laws found in (pure) mode A are also verified in three typical regions, independent of the Reynolds number, for (pure) mode B. Particularly, the mechanism for the physical origin of streamwise and vertical vortices in the shear layers is the vortex generation on the wall first and then dominant vortex induction just near the wall. The entire process of the formation and shedding of vortices with three components of vorticity is first and completely illustrated. Other characteristics of the evolution of mode B are presented in detail.

三维圆柱绕流的研究主要关注仿真精度,且单圆柱尾涡结构的分析较多,对于串列三圆柱绕流特征的研究较少.使用FLUENT软件对雷诺数为2.25×106在不同间距比下串列三圆柱的湍流模型进行三维模拟.运用Gambit软件对流场进行建模,并对圆柱临近水域网格进行加密,对串列三圆柱进行三维大涡模拟(LES);取间距比L/D(L为两圆柱间的距离,D为圆柱直径)为1.0、2.0和3.0,选取三维模拟中3个不同切面高度(距离水面0、2.25和4.40 m)研究速度场、压力场和涡量场的湍流特性.结果表明:三维模拟证实了表层的涡量变化显著,在连续圆柱后存在回流区域与间距比有强相关性;同时,3个不同切面的速度场变化较小,压力场变化甚微.

2021年12月,国际海事组织(IMO)第32届大会通过了关于"2018—2023六年期IMO战略计划"的决议,指出人为因素是IMO重点议题之一.随着船舶技术的进步,当今船舶的最低配员数量约为上世纪的50％,船员人力成本约占船舶营运成本的35％.众所周知,船员疲劳会给海上安全、保安和海洋环境保护带来重大风险.据美国海岸警卫队的统计数据:海员疲劳导致了20％的船舶损失和30％的船员伤亡.由于知识图谱在分析问题方面具有能够用可视化的图谱形象地描述知识资源的优势,所以运用知识图谱回顾海员疲劳的研究历程,有助于指导主管机关、船公司和船员等有效应对海员疲劳.通过国际海事组织文件网站IMO DOCS的文献检索、科学引文索引(SCI)和万方数据等检索上百篇文献,从国际、区域和公司等3个层面分类论述,对海员疲劳的相关技术进行对比分析.

2019-2021年三峡船闸过闸危险品运量保持平稳增长,年均危险货物过闸超900万吨.散装危险货物流向主要以上行为主,约占过闸危险货物总运量的82.8％,散装货物以油品和化学品为主,油船和化学品船占过闸危险货物船舶总量的99％.目前,针对危险品船舶的运输管理侧重于危险货物的管理上.

Barium titanate/polyvinylidene fluoride (BaTiO3/PVDF) piezoelectric membrane was successfully prepared and generated in-situ vibrations to reduce membrane fouling by applying alternating current (AC) signal for oily bilge water ultrafiltration. The effect of in-situ vibration on membrane fouling was investigated through changing in the excitation alternating voltage and its frequency, pH, crossflow rate. The results indicated that the piezoelectric membrane by applying AC signal remarkably alleviated the membrane fouling for bilge water ultrafiltration. The membrane fouling decreased with increasing the AC signal voltage. The final steady-state permeate flux from the piezoelectric membrane for bilge water ultrafiltration increased with the AC signal voltage, raising it by up to 63.4% at AC signal voltage of 20 V compared to that of the membrane without applying AC voltage. The high permeate flux was obtained at the resonant frequency of 220 kHz. During the 50-h ultrafiltration of bilge water with the piezoelectric membrane excited at 220 kHz and 15 V, the permeate flux from the membrane was stable. The oil concentration in outflow from the piezoelectric membrane was below 14 ppm, which met the discharged level required by IMO convention. The total organic carbon removal rate in bilge water was over 94%.

液化天然气(LNG)罐柜船舶进江靠港作业是水上运输的重要环节,有必要采取科学的安全保障措施.通过借鉴海港LNG罐柜水运风险和安全保障措施,并结合长江港口通航环境,系统分析LNG罐柜船舶航行、停泊装卸和应急锚泊等作业风险,进而提出进出长江内河港口不同航行阶段的安全保障措施.

随着船舶与导助航技术升级,内河船舶总体安全状态有所稳定,但近2年来因船舶驾驶台值班船员疲劳导致的船舶触礁碰撞事故与险情频发.通过引入国际海事组织(IMO)的疲劳指南和地平线项目成果,概述了值班船员的疲劳机理;结合内河船舶驾驶台视频监控技术,提出了夜间最佳值班站位的推荐方案;并结合交通领域的绿光防疲劳原理设计提出了一个内河船舶驾驶台值班船员疲劳预防装置.

船舶自身的装卸设备会对驾驶台的瞭望视野产生阻挡,从而引发了瞭望不全,导致驾引人员对周围通航环境不能及时全面掌握常引起判断错误和疏忽,进而引发事故.针对这一问题提出一种面向盲区的船舶视觉辅助瞭望方法,并设计了辅助驾驶信息可视化系统的总体框架.首先重复采集图像信息,直到搜索到正焦状态的位置,并利用视频识别技术进行识别;最后通过单目测距算法,测量出与目标船舶的距离以把握周围船舶动态.随后通过实验进行测试,结果验证了本系统能有效消除视野盲区、具有较强的适用性.

弯曲河段跨江桥梁的法向方向与水流流向夹角随着水位变动处于常年周期性变化,导致汛期水流流速大时船舶航行过桥会产生较大操纵环境压力.运用长江干线通航标准中的偏移量公式,建立流致漂移数学模型,收集典型忠州长江大桥汛期的水流数据和代表船型资料,计算不同工况下船舶航行下水过桥的漂移量,得出影响漂移量的水流流速、船舶速度和偏航角等定量关系.计算结果表明:汛期流速大且水流夹角变大时,船舶按照习惯航法或者低速航行时将产生较大的船撞桥墩风险.最后提出船舶操纵建议,并通过增设多功能航标,采集水文、气象信息提供给驾驶人员,以此来保障船舶航行安全.

本文对一种基于槽型微环谐振器的生物传感器进行了研究,通过微环谐振器与槽型波导的结合,增强光与传感媒质的相互作用,减小传输损耗的制约影响.采用时域有限差分法(FDTD)研究了波导有效折射率随传感物质材料折射率的变化,结果显示它们呈线性关系,这为折射率的有效传感提供了可能.采用电子束光刻和等离子体刻蚀技术在SOI基片上制备了样品,SOI基片的顶层硅和埋入氧化层的厚度分别为220 nm和2μm,微环谐振器的微环半径为30μm.采用波导光栅耦合器来实现光的输入和输出,频谱测量显示槽型微环谐振器的品质因数达到了2 940,通过测量传感器表面覆盖不同浓度的氯化钠溶液时光谱谢振峰的变化,得到传感器的灵敏度和检测极限分别为980.24 nm/RIU和5.4×10-4RIU.

In the present paper, the spatio-temporal evolution of vorticity in the first wake instability, i.e., (pure) mode A, is investigated in order to understand the wake vortex dynamics and sign relationships among vorticity components. Direct numerical simulation (DNS) for the flow past a circular cylinder is performed, typically at a Reynolds number of 200, in the three-dimensional (3-D) wake transition. According to characteristics of time histories of fluid forces, three different stages are identified as the computational transition, the initial stage and fully developed wake. In the second initial stage, the original two-dimensional spanwise vortices become obviously three-dimensional associated with the streamwise or vertical vorticity intensified up to about 0.1. As a matter of fact, these additional vorticities, caused by the intrinsic 3-D instability, are already generated firstly on cylinder surfaces early in the computational transition, indicating that the three-dimensionality appeared early near the cylinder. The evolution of additional components of vorticity with features the same as mode A shows that (pure) mode A can be already formed in the late computational transition. Through careful analysis of the vorticity field on the front surface, in the shear layers and near wake at typical times, two sign laws are obtained. They illustrate intrinsic relationships among three vorticity components, irrelevant to the wavelength or Fourier mode and Reynolds number in (pure) mode A. Most importantly, the origin of streamwise vortices is found and explained by a new physical mechanism based on the theory of vortex-induced vortex. As a result, the whole process of formation and shedding vortices with these vorticities is firstly and completely illustrated. Other characteristics are presented in detail.

The paper intended for analyzing staff's behavioral characteristics when it need of emergency evacuation, studied passenger ship evacuation of stairs, and establish evacuation time model. The paper considered personnel's distribution, density, speed, gather and etc. Examples show the results are consistent with the actual situation, so this model can be used to guide the development of the evacuation plan.

非常规水上应急管理是水上交通安全领域的新挑战.通过回顾2018年10月28日的万州公交车坠江事件和救助打捞过程,概括了三峡库区非常规水上突发事件的事故特征与救助难点;为落实2019年交通运输部重点工作"开展长江干线水上应急救援能力提升专项行动",适应三峡库区水上应急管理改革,从"巩固、推进、整合和创新"4个层面提出了面向高质量人命救助的三峡库区应急能力提升策略.

Microplastics and organophosphate esters are ubiquitous pollutants in the marine environment. However, their interactions are poorly understood. In the present study, the sorptions of tri-n-butyl phosphate (TnBP) and tris(2-chloroethyl) phosphate (TCEP) on polyethylene (PE) and polyvinyl chloride (PVC) microplastics in seawater were investigated. Results indicated that the first-order kinetic model and pseudo-second-order were suitable to describe PE and PVC microparticles for the adsorption of the two organophosphate esters, respectively. The adsorption capacity increased with the decrease in particle size. The highest adsorption capacity appeared at 15 °C. The equilibrium isotherms data for the adsorption of the two organophosphate esters on PVC and PE microplastics were best fitted with Freundlich isotherm model and Langmuir isotherm model, respectively. The pore-filling mechanism involved in the adsorption of TnBP and TCEP on PVC microplastics and the monolayer coverage was the predominant mechanism for the adsorption of TnBP and TCEP on PE microplastics.

We studied the four-wave mixing in photonic waveguides including crystal silicon waveguide, amorphous silicon waveguide, and silicon nitride microring resonator. The devices were fabricated by using electron-beam lithography and inductively coupled plasma etching technologies. The spectra of four-wave mixing process were measured by using the optical spectrum analyzer. The pump power dependences of the conversion efficiencies were analyzed according to the measured spectra. The amorphous silicon waveguide works more efficient than the crystal silicon waveguide. Silicon nitride microring resonator enhanced the conversion efficiency effectively by about 8.0 dB.

客船安全隐患区别于事故险情,一般通过客船事故调查分析与客船安全检查分析途径获得,针对50份专家问卷调查,确定评价指标权重,建立长江干线客船安全隐患评价指标体系,其中包括船员、船舶、环境和管理4个二级指标和13个三级指标,运用模糊综合评价法,构建了客船综合安全综合评价模型.分析结果表明,基于模糊综合评价法的客船安全隐患评价具有一定的实用性和有效性.