简介：

简介：文章通过对MAN-K9260／105E型柴油机因人为原因造成的气缸盖裂纹损坏，从理论上进行了分析和探讨，从气缸盖的结构特点、工作条件等方面提出日常管理、操作以及维护中的注意事项，希冀为轮机管理人员处理类似情况提供参考。

简介：

简介：

简介：

简介：Basedontheprincipleofimpedancemismatching,theperformanceofrigidvibrationisolationmassinimpedingvibrationwavepropagationwasdiscussedfromtheperspectiveofwaveapproach.BasedonFEM,theinfluenceofitsweightaswellasthecross-sectionshapeparametersontheisolationperformanceofrigidvibrationisolationmasswasstudiedthroughnumericalsimulation.Theresultsshowthatrigidvibrationisolationmasscaneffectivelyimpedethepropagationofthemediumandhighfrequencyvibrationwaves,andtheheavierthevibrationisolationmass,thebettertheisolationperformance.Forlowfrequencywaves,thevibrationisolationeffectisnotsoobvious;forarectangularvibrationisolationmass,theisolationperformancecouldbeeffectivelyimprovedbyincreasingthecross-sectionheightandreducingthecross-sectionwidth.Ausefulreferencewasprovidedfortheapplicationofrigidvibrationisolationmassestothevibrationisolationandnoisereductionofshipstructure.

简介：介绍了一种基于Spalding公式拟合的脊状表面减阻测试方法，相比于用天平等测力设备测试的方法，其优点在于简便实用，从应用实例来看，准确性也是令人满意的．由于该方法依靠的数据基础是壁面边界层内层速度分布，因此，速度分布测量的准确程度是影响该方法测试结果准确与否的决定因素．

简介：Inconsideringthetheoryofstructuraldynamicoptimizationdesign,adesignmethodofthestructuralstyleofshipcompositebracewithrigidvibrationisolationmasswasstudied.Twokindsofstructuraldynamicoptimizationformulationsminimizingthevibrationaccelerationofthenon-pressurehullontherestrainingconditionofthegrossweightoftheshipcabinwereestablished:1)dynamicoptimizationofthesectionaldimensionsoftherigidvibrationisolationmassinthecompositebrace;2)dynamicoptimizationofthearrangingpositionoftherigidvibrationisolationmass.Throughtheoptimizationresults,sectionaldimensionsandthearrangingpositionoftherigidvibrationisolationmasswithbetterperformanceinreducingvibrationweregained,andsomereferencewasprovidedforpracticalengineeringdesignsaswellasenrichmentofthedesignmethodofanovelshipvibration-isolationbrace.

简介：Rigidblockingmassesarelocatedinthetypicalbasestructureofapowercabinbasedontheimpedancemismatchprinciple.Bycombiningtheacoustic-structuralcouplingmethodandstatisticalenergyanalysis,thefull-bandvibrationandsoundradiationreductioneffectofvibrationisolationmasseslocatedinabasestructurewasresearched.Theinfluenceoftheblockingmass’cross-sectionsizeandshapeparametersandthelayoutlocationofthebaseisolationperformancewasdiscussed.Furthermore,theeffectivenessofrigidvibrationisolationdesignofthebasestructurewasvalidated.Theresultsshowthatthemediumandhighfrequencyvibrationandsoundradiationofapowercabinareeffectivelyreducedbyablockingmass.Concerningweightincrementandsectionrequirement,suitablyincreasingtheblockingmasssizeandsectionheightandreducingsectionwidthcanresultinanefficiency-costratio.

简介：2013年世界100强港口总吞吐量增长3％，2014年随着世界经济缓慢复苏，100强港口总吞吐最增长5．6％。其中，2014年中国虎门港增长速度惊人，吞吐量增加49．8％，主要原凶得益于虎门港自2012年起成功引入PSA国际港务集团和中国外运长航集团两大航运物流强势企业对港口码头实行专业管理经营。

简介：2016年8月底，Lloyd’sList正式公布了2015年世界集装箱港口吞吐量前100名排名。尽管受经济危机影响，集装箱行业普遍低迷，2015年大多数港口的吞吐量还是保持了一定的增长，但整体来看，港口吞吐量的增长显著放缓。其中，前100强港口有46个港口来自亚洲，世界前10名中亚洲占据九席，上海港继续拔得头筹，唐山港新进入百强，中国共计有20个港口进入前100强，占五分之一。