简介：自中国2001年加入WTO以来，受国民经济强势增长的推动，中国的集装箱出口也实现快速增长。然而近年来，中国集装箱出口的整体增速有所放缓，由此也使得中国大陆港口的集装箱吞吐量增长趋势减弱。即便如此，中国大型港口和小型港口之间的发展趋势却不尽相同。

简介：4月初中国出口集装箱运输市场总体需求不稳，由于各大联盟航线处于协调磨合期，运价上涨态势减弱。中旬多数航线运输需求趋于平稳，各航线运价波动较小。月末迎来节前高峰，部分航线舱位紧张，运价上涨态势明显。

简介：船舶锅炉用水的处理，各种教材均从不同侧面介绍了具体方法，但是对水处理的机理、处理的原因没有作具体分析,文章运用化学知识，对水处理的重要性、水处理的原理、投药的具体计算方法进行了详细的论述，以便为现实操作提供可参考的方法。

简介：Ananalyticalstudywaspresentedonactivecontrolofsoundtransmissionintoavibro-acousticenclosurecomprisingtwoflexibleplates.Twotypesofactuatorswereused,i.e.acousticactuatoranddistributedleadzirconatetitanatepiezoelectric(PZT)actuatorinsteadofpointforceactuator.Usingthemodalacoustictransferimpedance-mobilitymatrices,theexcitationandinteractioninthecoupledsoundtransmissionsystemcanbedescribedwithclearphysicalsignificance.Withthecontrolsystemdesignedtogloballyreducethesoundfield,differentcontrolsystemconfigurationswereconsidered,includingthestructuralactuatorontheincidentplate,actuatoronthereceivingplate,acousticactuatoronthecavity,andtheircombinations.Theeffectivenessandperformanceofthecontrolstrategycorrespondingtoeachsystemconfigurationwerecomparedanddiscussed.Theroleandcontrolmechanismofeachtypeofactuatorwereofparticularinterest.Itwasshownthattheincidentplateactuatoriseffectiveincontrollingthecavity-dominatedmodesandthestructuralmodesdominatedbytheincidentplateandreceivingplate.Twomaincontrolmechanismsareinvolvedinthiscontrolconfiguration,i.e.,modalsuppressingandmodalrearrangement.Forcontrolsystemconfigurationwithonlyacousticactuatorintheenclosure,themechanisminvolvedinthisarrangementispurelymodalsuppression.Desirableplacementsofstructuralactuatorsintermsoftotalpotentialenergyreductionwerealsodiscussed.