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IntroductiollAnyelectricalconductorplacedinatime-varyingmagneticfieldistheseatofeddycurrentsthatdissipatepowerthroughJouleeffect.ThispowerisconcentratedinthesurfaceofthecomPonent,inaverysmallthicknesswhichdependsontheelectricalconductivityandmagneticpermeabilityofthematerial,butalsoonthefrequencyofthecurrents.Inductionhardeningprocessestakeadvantageofthiseffectbecauseitthereforepossibletocontrolthethicknessofthetreatedlayer.InductionhardeningofsteelcomPonentsisrealisedintwosteps.First,anindu…  相似文献   
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Abstract

An increasing threat to the marine environment is the presence of debris in the ocean, which is predominantly a result of land-based sources and increasing use of single-use packaging items. To begin reducing the amount of debris entering the ocean, human behavior must be addressed. The purpose of this study is to evaluate how coastal recreationists behave towards the environment and whether their participation in recreation correlates to their reported behavior specific to marine debris control. Path analysis was used to determine how one’s attitudes, knowledge, recreational activity, and background characteristics influence behavior. Results showed that type of recreational activity had very little impact on behavior and other predictors. From the model, marine environmental concern, connection to the marine environment, and gender most directly influenced reported behavior. Therefore, to encourage change in recreationists’ relevant behavior, the results indicate social groups where behavior change efforts could initially be made. Additionally, the marine environmental concerns of different demographic groups should be considered and used in developing programs directed at increasing environmentally responsible behavior with emphasis on marine debris.  相似文献   
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IntroductionItiswellknownthaphasetrapsformationsplayanimPortantroleontheresidualstressesandstrainsinducedbythermalprocessessuchasweldingandquenching.lnthispaPer,wefocusourattentiononthebehaviourofsteelsduringphasetransformations.AtheoreticalaPproachhasbeenachievedbyLeblondetal[1]andhasledtOamacroscopicmodelinthecaseofideal-plasticphases[2][3].Thenthemodelhasbeengeneralizedtotakestrainhardeningphenomenaintoaccount[4].ThetheoreticalaPproachhasbeenassessedandcompletedusingflniteelementsimulati…  相似文献   
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P. R. Lyon 《运输评论》2013,33(4):369-391
Abstract

The freedom of the seas, or the right of innocent passage whereby the Master of a ship may proceed as and how he chooses has, in recent years, come under considerable public scrutiny. This scrutiny has resulted in an increasing intervention by land‐based authorities to limit the traditional freedoms, by means of regulating the flow of shipping movements.

This review therefore examines the reasons behind the public scrutiny and gives a history of the development of the shore‐based regulation of shipping movements, with examples of international, national and local measures taken. The effectiveness of such measures in terms of reducing accidents is discussed, drawing upon the results of surveys undertaken in a number of countries.

This, in turn, suggests criteria for determining the degree and type of shore‐based intervention appropriate to a given waterway, and permits certain conclusions to be drawn. Finally, future developments now under discussion are described, with a commentary on further developments now possible with modern technology.  相似文献   
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IntroductionAwiderangeofweldingorsurfacetreatmentprocessesinvolvetheuseofaheatsourcemovingataconstantspeedoverthesurfaceofthecomPonent.ThreedimensionalcomPutationofresidualstressesanddistortionsinducedbythiskindofprocesses,usingtheusualfiniteelementmethod,needsveryrefinedmeshesinordertocorrectlydescribethepropertiesandstressgradientsintheheataffCctCdzonealongthepathoftheheatsource.Inthispaper,wediscussthedifferentnumericalaPproaches,imPlementedinSYSWELD@software,whichcanbeusedtodorealisti…  相似文献   
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