简介：基于国内经济形势向好的背景下,预计下半年全国规模以上港口货物吞吐量增速将有所回升。结合目前最新数据,预计2018年年货物吞吐量增速将保持在4%左右,总量达132亿吨左右。

简介：《中华人民共和国船舶吨税法》（简称＂吨税法＂）于7月1日正式实施。吨税法较以往有4处明显改进：一是确认了吨税执照电子信息的法律效力,为海关吨税申缴无纸化改革提供了法律支撑;二是明确了警用、改造船舶的免征吨税资格,保障了执法和民生需要;三是将多缴吨税的退税申请时间由一年延长为三年,更加符合进出境船舶的作业特点。

简介：在对重庆市轨道交通6号线东水门长江大桥和千厮门嘉陵江大桥施工方案研究的基础上,提出满足大跨度钢桁梁斜拉桥面直接铺设整体道床的技术方案.该方案通过线性监测、模拟评估、技术对比分析等,克服了铺设整体道床轨道时桥面系受温度、二期恒载、活载振动影响的诸多不利因素,满足了大跨度钢桁斜拉桥铺设整体道床的技术要求.

简介：Acomplianttowerismodeledasapartiallydry,partiallytapered,dampedTimoshenkobeamwiththesuperstructuremodeledasaneccentrictipmass,andanon-classicaldampedboundaryatthebase.Thefoundationismodeledasacombinationofalinearspringandatorsionalspring,alongwithparallellinearandtorsionaldampers(Kelvin-Voigtmodel).Thesuperstructureaddstothekineticenergyofthesystemwithoutaffectingthepotentialenergy,therebyreducingthenaturalfrequencies.Theweightofthesuperstructureactsasanaxialcompressiveloadonthebeam,reducingitsnaturalfrequenciesfurther.Theemptyspacefactorduetothetruss-typestructureofthetowerisincluded.Theeffectofsheardeformationandrotaryinertiaareincludedinthevibrationanalysis;withthenon-uniformbeammode-shapesbeingaweightedsumoftheuniformbeammode-shapessatisfyingtheendcondition.TheweightsareevaluatedbytheRayleigh-Ritz(RR)method,andverifiedusingfiniteelementmethod(FEM).Theweightofthesuperstructureactsasanaxialcompressiveloadonthebeam.Kelvin-Voigtmodelofstructuraldampingisincluded.Apartofthestructurebeingunderwater,thevirtualaddedinertiaisincludedtocalculatethewetnaturalfrequencies.Aparametricstudyisdoneforvariousmagnitudesoftipmassandvariouslevelsofsubmergence.ThecomputationalefficiencyandaccuracyoftheRayleigh-Ritzmethod,ascomparedtotheFEA,hasbeendemonstrated.Theadvantageofusingclosed-formtrialfunctionsisclearlyseenintheefficacyofcalculatingthevariousenergycomponentsintheRRmethod.