船舶伙食冷库压缩机制冷量的预测

船舶伙食冷库的所配用的压缩机制冷量同伙食冷库的库容大小存在着一定的函数关系,本文通过实船设计的样本数据采用曲线拟合的方法,推导出压缩机制冷量关于冷库库容的函数,并由此生成冷库库容和压缩机制冷量的关系曲线,对于在设计初期快速预测伙食冷库制冷压缩机的制冷量有实际应用意义.     

Investigation of the effectiveness of tandem oil fences under currents

The behavior of the flow passing a tandem oil fence, and the performance of the fence, were investigated by experimental and numerical methods. The flow characteristics between tandem fences were measured by the particle image velocimetry (PIV) method for the rigid and open free surface between the two fences in order to gather reference data for numerical investigations. A method of assessing a tandem fence by tracing the movement of an oil droplet around the fence is introduced. The effect of the current speed, the separation distance between the two fences, the relative draft of the two fences, and the water depth on the oil containment between the fences was investigated.     

港口物流与区域经济协同发展研究*

阐述了港口物流与区域经济的相互关系,利用灰色综合关联度模型对重庆市港口物流与区域经济之间的相关性进行实证分析,结果表明两者存在着高度的相关性;同时通过多维灰色GM(1, N)模型分析了两者之间的协调程度,得出重庆市港口物流与经济增长整体上协调,有一定的发展能力,但是两者之间同时存在某些不协同因素。最后根据分析的结果提出了相关建议以促进港口物流的发展,进而实现与区域经济的良好互动。     

桥梁上部结构防船撞研究

船舶撞击桥梁上部结构是船撞桥事故模式之一,其撞击特性与撞击桥墩特性相比有所不同。现着重研究了船舶撞击桥梁上部结构的风险分析、撞击力、防撞保护等技术问题,并提出设置警示设施、AIS系统建设、拦截、红外线监测、警戒等防护措施,供通航安全部门参考。     

混凝土渗透性“PERMIT”测试方法探索

为了探寻“PERMIT”离子迁移方法与现行标准推荐方法的关系,对不同胶凝材料体系混凝土分别进行了“PERMIT”离子迁移试验及RCM快速氯离子迁移试验.通过对“PERMIT”阳极室溶液进行定量分析,发现胶凝材料体系变化对阳极室溶液浓度变化率与电导变化率关系影响不显著,进而建立了两者的普适关系.试验结果表明,“PERMI...     

某船用柴油机齿轮箱端盖安装间隙值研究

某船用柴油机齿轮箱端盖在设计时,齿轮轴两侧滑动轴承采用翻边整体轴套设计。在齿轮箱端盖和齿轮箱箱体之间设置初始间隙,通过端盖螺栓的预紧力作用来保证轴套的固定。针对齿轮箱安装工况,采用有限元法对轴套变形以及齿轮箱端盖与箱体之间的间隙值进行了计算和分析,研究了螺栓预紧载荷对轴套变形和齿轮箱端盖与齿轮箱之间的间隙值的影响规律,为合理的确定齿轮箱端盖螺栓预紧载荷以及设定对应的初始间隙值提供了依据。     

哈夫边舵柄结构强度有限元计算

某船边舵柄设计时所取的舵杆与拉杆轴线距离不足造成舵柄与拉杆之间产生干涉现象，为此在舵柄上切削出一个平面，为了保证该哈夫边舵柄在设计载荷作用下有足够的强度，采用有限元方法对其结构强度进行直接计算和校核。     

导管参数对导管桨水动力性能的影响研究

基于CFD数值计算,计算19a导管与Ka4-70桨敞水性能。研究了导管长度,前缘形状以及导管与桨之间的间隙变化对导管桨敞水性能的影响。计算结果表明,导管能够改善螺旋桨尾流。对于导管长度,存在最优长度使得导管桨敞水性能最好。19a导管前缘形状是最优的,改变前缘形状会降低导管桨的敞水性能。当间隙在一定范围内,导管与螺旋桨之间间隙越小,敞水性能越好。非对称上下间隙对导管桨的敞水性能影响较小。     

港口与城市环境及资源的协调发展度研究

随着我国港口和城市建设的不断发展,在生态环境和资源利用方面港城间的矛盾日益明显,如何协调两者之间的发展已成为目前迫切需要解决的课题。为此,以大连市为例,从建立港城协调发展度模型入手,对港口与环境及资源之间协调的程度进行评判,从而为指导港口和城市的可持续发展提供了决策依据。     

关于船用齿轮机构输入功率的补偿

船舶航行时船体中拱及中垂弯曲变形使沿船体纵向布置的齿轮机构的轴承支座中心距产生缩减.这种中心距缩减会导致互相啮合的两齿轮间产生附加的径向压力,从而使齿轮机构处于双面啮合工作状态.本文分析及计算了齿轮机构在该双面啮合工作状态时齿间摩擦及轴承摩擦所消耗的功率,并提出能满足船用齿轮机构正常运行要求的输入功率补偿公式.     

一种分析线天线互耦的新方法

天线之间的耦合影响是短波通信台站建设中必须考虑的一个重要因素，采用SuperNEC（Super Numerical Electmmagnetics Code）线数值计算软件与微波网络理论相结合的方法分析了短波线天线之问的耦合影响。该方法先将多天线系统等效为微波网络，然后通过SuperNEC仿真软件得出天线分布电流并计算出等效网络的导纳矩阵Y，利用该导纳矩阵Y就可得到天线之间的耦合度。分析证明该方法理论正确。并且对多天线的安装布局有重要的指导作用。     

Competing for level of service in the provision of mobility services: Concepts, processes and measures

One of the most striking problems societies currently deal with is to assure adequate quality standards while improving accessibility within and between cities. In addition there is also a growing awareness that, to achieve a sustainable balance between private and public means of mobility, policies have to be able to send the correct signals in order to induce users adaptive behaviour, which in turn will provide the system with a reliable feedback on the needs for further investment and expansion of transport facilities. The definition and measurement of quality of service of the transport system is thus an objective aimed by both users and producers and it is often represented by the rather holistic concept of Level of Service (LoS). However, the LoS concept is not consciously used by users, on the contrary the user concentrates her comparative evaluation on what is simply known as quality. It is the planner that translates planned quality into LoS concept. So, LoS is a concept at the interface between the provider and the user. Given the interface character of the LoS concept an accounting framework for LoS should thus take into account the need to segregate the evaluation for passengers and freight transport and also distinguish between types of travellers in the case of passenger transport and types of commodities or logistic families in the case of freight transport. Moreover the bridge between the planner and the user view must be ensured. This paper reports the results of a research work dedicated to this topic.     

桨舵间距对螺旋桨推进性能影响的研究

利用CFD数值工具对原型以及减少桨舵间距后的布置进行数值模拟,量化其节能效果,并通过模型试验进行验证。CFD和模型试验结果均表明,减少桨舵间距对于提高螺旋桨推进性能有明显效果。以某3万吨级散货船为例,模型试验结果显示,减少桨舵间距0.5m后,收到功率降低3.1%,航速提高0.13kn。目前市场上运行的三大主力船型中,有相当数量船舶的桨舵间距仍有一定调整空间,表明这项研究成果具有良好的市场应用前景。     

应用小波变换进行压缩中分解层次的一种确定方法

提出用小波变换进行信号压缩时对于小波分解层次的一个择优方法。大量实验表明小波分解层次的选取直接影响到重构信号的各方面指标参数。从重构信号与原信号之间的相对误差为出发点和压缩指标，通过实验分析了分解层次与压缩效果之间的简单关系。分析结果表明。二者之间确实存在着某种函数关系，通过简化数学关系得到了分解层次的确定方法。该方法经过检验基本上能准确的反映分解层次与压缩效果的关系，是一种较为有效的分解层次确定方法。     

Application of the Principles of ICZM for Restoring the Goro Lagoon

The Goro lagoon has been adversely affected by intense anthropogenic impacts, which have resulted in deterioration of the lagoon's environmental health. An intervention at the lagoon's secondary mouth was done in order to improve the water exchange between the lagoon and the sea and to reclaim the lagoon's floor. This intervention comprised reprofiling the submerged sandspit platform and the tidal channel and nourishing the barrier island. After completion of the intervention, clam production increased by 28% and the lagoon's ecological quality substantially improved. The project utilized some of the eight principles of integrated coastal zone management to reach the best compromise between the socioeconomic needs and preservation of the lagoon. The realization of the successful intervention was first secured in a memorandum of agreement that was drafted by negotiations between the Emilia-Romagna Region Council, the Province of Ferrara, Goro Municipality, and the local fishermen's association. Two committees managed the intervention and ensured that all stakeholders participated in the decisionmaking process. The collaboration between public and private sectors enabled the forging of a cost-effective intersectoral intervention with a long-term perspective, which fulfilled the specific ecological needs of the lagoon and guaranteed sustainable development for the lagoon's adjacent human communities.     

回转角速度指示器在船舶操纵中的应用

简要地陈述了船舶定常回转时其对地速度、回转半径和回转角速度之间的关系;介绍了回转角速度指示器在船舶航行过湾道及大幅度转向和其他航行及避让条件下的应用及预算相应回转角速度的方法,还采用了笔者本人参加“海河下游通航标准研究”时对实船航行和船舶数学模型的模拟航行数据所测定的回转数据与预算值进行了比较;同时对如何在实际中正确使用角速度指示器提出了一些应注意的事项和建议。     

立靶密集度指标对舰炮武器系统命中概率的影响

文章分析了影响舰炮武器系统射击精度的几个因素,并以某型舰炮为例,利用典型数据对立靶密集度与命中概率的关系进行了仿真计算,总结了舰炮立靶密集度指标与系统精度的关系。     

两岸直航经济博弈分析

通过采用子博弈精练纳什均衡理论分析的方法,分析两岸迟迟不能实现海上直航的原因。贸易是两岸直航的主要动力;只有当两岸贸易发展到较高程度时,航运业者才会赞成两岸实现直航。此外,有一种实现海上直航的特殊情况存在:两岸贸易的受损集团力量较强却赞成直航,即使两岸贸易发展较弱,也可能实现海上两岸直航。     

Land Changes and Conflicts Coordination in Coastal Urbanization: A Case Study of the Shandong Peninsula in China

The coastal zone is an interaction region between land and ocean and an interface of geosphere, hydrosphere, atmosphere, and biosphere, as well as greatly affected by human activities. Driven by economic activities and increased population, urbanization is rapidly developing in coastal zones, and a series of land resource and environmental conflicts have occurred, especially in developing countries at times of economic transition. This article reports a case study of the Shandong Peninsula of East China. We analyze the land-use practices and land cover changes of six cities over a timeframe of nearly a decade. We then review the management conflict issues. The most commonly encountered conflicts fall into three categories: those between expanding constructed land and decreased cultivated land; those between land resource utilization and conservation; and those between increasing demand for land and degrading land quality. All in all, they reflect the fundamental conflicts between short-term economic development gains and long-term food security and ecosystem sustainability. This article puts forward an institutional approach to coordinate these conflicts so as to realize integrated and coordinated coastal management.     

关于天津港泥沙回淤程度的评价

关于港口泥沙回淤程度的评价指标与标准,国内、外目前尚无专著文献.依据天津港多年的有关资料,采用“挖泥吞吐比”、“淤强水深比”两个指标,提出了港口泥沙回淤程度的分类标准,并对天津港总体和分区的回淤程度进行了评定.