建立完善中国船舶污染防治法规体系的必要性及建议

完善的船舶污染防治法规是搞好中国船舶污染防治工作的基础，但中国现有船舶污染防治法规还存在着各部分发展不平衡、法规不健全等问题。要完善中国船舶污染防治法规，必须以体系的观点对现有船舶污染防治法规进行审视，把其建设成为一套有别于其它污染防治法规的完善的、相对独立的体系。文中就此展开论述并提出了相应的建议。     

Fuzzy experts on recreational vessels, a risk modelling approach for marine invasions

Understanding risks from the human-mediated spread of non-indigenous species (NIS) is a critical component of marine biosecurity management programmes. Recreational boating is well-recognised as a NIS pathway, especially at a regional scale. Assessment of risks from this pathway is therefore desirable for coastal environments where recreational boating occurs. However, formal or quantitative risk assessment for the recreational vessel pathway is often hampered by lack of data, hence often relies on expert opinion. The use of expert opinion itself is sometimes limited by its inherent vagueness, which can be an important source of uncertainty that reduces the validity and applicability of the assessment. Fuzzy logic, specifically interval type-2 fuzzy logic, is able to model and propagate this type of uncertainty, and is a useful technique in risk assessment where expert opinion is relied upon. The present paper describes the implementation of a NIS fuzzy expert system (FES) for assessing the risk of invasion in marine environments via recreational vessels. The FES was based on expert opinion gathered through systematic elicitation exercises, designed to acknowledge important uncertainty sources (e.g., underspecificity and ambiguity). The FES, using interval type-2 fuzzy logic, calculated an invasion risk value (integrating NIS infection and detection probabilities) for a range of invasion scenarios. These scenarios were defined by all possible combinations of two vessel types (moored and trailered), five vessel components (hull, deck, internal spaces, anchor, fishing gear), two infection modes (fouling, water/sediment retention) and six frequently visited marine habitats (marina, mooring, farm, ramp, wharf, anchorage). Although invasion risk values determined using the FES approach was scenario-specific, general patterns were identified. Moored vessels consistently showed higher invasion risk values than trailered vessels. Invasion risk values were higher for anchorages, moorings and wharves. Similarly, hull-fouling was revealed as the highest infection risk mode after pooling results across all habitats. The NIS fuzzy expert system presented here appears as a valuable prioritising and decision-making tool for NIS research, prevention and control activities. Its easy implementation and wide applicability should encourage the development and application of this type of system as an integral part of biosecurity, and other environmental management plans.     

大型相连容器中火焰传播的研究

为了进一步了解相连装置中粉尘爆炸的火焰传播行为和压力发展,为该结构的安全防护设计提供有价值的信息,采用大型实验装置对相连容器中玉米淀粉/空气混合物爆炸时的火焰传播行为进行了实验研究,同时采用已开发的数值模型对实验进行仿真计算。实验表明:粉尘浓度的变化对粉尘爆炸的火焰传播行为有重要影响;在粉尘浓度很低的情况下,火焰仍然能够在管道中加速传播且爆炸发展的最终结果相当猛烈。数值模型采用欧拉-拉格朗日方法模拟两相流现象,通过求解非稳态的湍流两相反应流守恒方程对实验进行二维仿真,计算结果与实验结果符合性较好,表明该模型可以很好地应用于粉尘爆炸火焰传播的研究。     

舰船电子设备可维性设计对策

本文就目前舰船电子设备研制过程中存在的维修性问题，从结构设计角度探讨了舰船电子设备维修性的设计要求，以及提高舰船电子设备结构维修性和战备完好率的基本思路和对策。     

重庆境内江河水域渔业环境特点及对船体网箱养鱼的影响

重庆境内河流属长江水系，以长江，嘉陵江，涪江等河流为骨干和主体，水域面积８．２５万ｈａ，占水域总面积的７６．４％，船体网箱养鱼是近年来在该地区兴起并迅速发展的鱼类集约化养殖方式。本文根据船体网箱养鲤试验结果和有关资料，分析了重庆境内江河水温，含氧量，流速，含沙量，浮渣，工业污染特点及对船体网箱养鱼的影响，拟合了养殖舱内，外流速关系及含沙量与透明度关系，并就船体网箱养鱼的进一步发展提出了措施。     

Case study: Assessment on large scale LPG BLEVEs in the 2011 Tohoku earthquakes

After the 2011 Tohoku earthquakes, several chemical and oil complexes on the Pacific Ocean shoreline of northeast Japan experienced massive losses. In Chiba, a refinery operated by Cosmo Oil lost 17 LPG storage vessels which were either heavily damaged or totally destroyed by fires and explosions in the refinery. These large vessels ranged in size from 1000 to 5000 m³. The estimated volume of LPG at the time of the incident was between 400 and 5000 m³ for each vessel. Five boiling liquid expanding vapor explosions (BLEVEs) of LPG occurred, resulting in huge fire balls measuring about 500 m in diameter.A BLEVE is defined as the explosive release of expanding vapor and boiling liquid when a container holding a pressure-liquefied gas fails catastrophically. It is thus important to estimate the physical properties of superheated liquids: the thermodynamic and transport properties, the intrinsic limits to superheating and depressurization, and the nature of thermodynamic paths. Also it is hoped to provide better understanding of the vessels designed, manufactured, installed, and operated to reduce or eliminate the probability that a sequence of events will result in BLEVE or loss of primary containment. Knowledge of these matters is still incomplete. The objective of this research is to estimate the significant BLEVE phenomenon in very large scale spherical vessels based on published information in Japan. There are some models predicting BLEVEs. However, it is essential to know if this is true for very large scales such as spheres since validation is usually rare to provide confidence in estimating the superheated liquids behaviors. To this end, comparing with the information on this event, the conditions in the five LPG vessels at the time of the BLEVE were determined in terms of: duration of vessel failure (time to BLEVE); mass fraction in the vessel with time; temperature distribution in the liquid and vapor region and pressure within the vessel (e.g. initial pressure and internal high-speed transient pressure during failure), by means of a computer program AFFTAC Analysis of Fire Effects on Tank Cars, which solves heat conduction, stress and a failure model of the tank, a thermodynamic model of its fluid contents, and a flow model for the lading flowing through the safety relief device. Subsequently, the consequences from the sphere BLEVE, such as the expected fireball diameter and duration and the expected blast overpressure produced by the BLEVE failures, are also subjects of active research. Here the blast using the methods of PHAST and SFPE Handbook of Fire Protection Engineering was calculated.Results suggest that methodologies here used gave reasonable estimations for such real and huge BLEVEs in a validated way, which may provide valuable guidance for risk mitigation strategy with regard to LPG facility in design, emergency planning, resiliency, operations, and risk management.     

高流速海水中舰艇常用材料腐蚀实验研究

介绍了舰艇常用材料在海水环境动态高流速条件下自然电位、自然腐蚀率、电偶腐蚀等多方面的腐蚀实验方法及实验结果,得出了舰艇常用系列材料在动态海水中的腐蚀基本数据以及变化规律,为在舰船设计中材料的选择及腐蚀防护方案的制定提供参考。     

长江干线船舶碰撞原因的故障树分析一以武汉海事局辖区水域为例

以2007年武汉海事局辖区船舶碰撞资料为基础,利用故障树分析方法构建该水域船舶碰撞故障树,进行定性、定链分析,得到包括航行疏于戒备、车舵控制失误、疏于了望等14个主要危险因素及各因素的相关事故数。在故障树分析的基础上,构建布尔代数和最小割集,计算各危险旧素的概率重要度,以衡精各危险因素发生概率的变化给碰撞事故发生概率带来的影响;计算临界重要度,从敏感度和概率双重角度衡量每个危险因素的重要度。通过分析发现应急操作不当、违反其他规定、航行疏于戒备、违反分道通航、疲劳驾驶等人为因素是引起该水域船舶碰撞的重要原因。建议船公司重视船员应急培训,提高船员应急处置能力,海事管理机构加大相关法规宣传力度和监管力度。     

辽宁省港口邻近区域海运废气排放测算

为准确测算沿海地区船舶废气排放量,基于试验数据确定了NO_x、CO、HC和CO₂排放因子;结合文献资料和海事局进出港船舶签证数据,采用基于船舶活动过程的方法测算了2014年辽宁省港口邻近区域〔距港口减速区外边界25 n mile(1 n mile=1 852 m)以外的边界线与港口陆地岸线所围成的区域〕海运废气排放清单. 结果表明:2014年辽宁省港口邻近区域海运NO_x、CO、HC、CO₂、SO₂和PM(颗粒物)的排放量分别为11 827.1、971.4、399.6、1 097 426.5、11 654.1和959.2 t;散货船、集装箱船和油船3种主要类型船舶的NO_x、CO、HC、CO₂、SO₂和PM的分担率之和分别为74.7%、77.8%、70.8%、68.0%、70.9%和70.6%;主机NO_x、CO、HC、CO₂、SO₂和PM的分担率最大,分别为63.7%、63.0%、46.0%、40.4%、46.4%和45.3%;停泊工况下的NO_x、CO、HC、CO₂、SO₂和PM排放量分别为3 318.3、281.7、168.3、520 194.9、4 894.0和411.5 t. 船舶降速运行、减少停港时间、燃用低硫油和向船舶供应岸电等措施能降低港口邻近区域海运废气排放. 基础数据缺乏或数据代表性不足给废气排放清单带来了一定的不确定性.      

压力容器定期检验体积缺陷高度的简易检测

利用曝光曲线和胶片特性曲线,推导了焊缝内部体积缺陷高度的计算公式,缺陷高度计算公式适应于焊缝表面比较平滑的体积型缺陷计算。通过测量缺陷处底片黑度、缺陷附近焊缝处底片黑度、缺陷附近母材处底片黑度、缺陷附近焊缝高度,可以用公式计算焊缝内部体积缺陷高度,该公式能够应用于未焊透和条状夹渣的高度测定,并在压力容器定期检验时对未焊透和条状夹渣缺陷安全状况进行定级。