翻訳と辞書 Words near each other ・ Bed bug (disambiguation) ・ Bed bug control techniques ・ Bed bug infestation ・ Bed burial ・ Bed Dance ・ Bed danced ・ Bed dancer ・ Bed dancers ・ Bed dances ・ Bed dancing ・ Bed for Two; Rendezvous with Luck ・ Bed frame ・ Bed Head ・ Bed Intruder Song ・ Bed jacket ・ Bed load ・ Bed management ・ Bed material load ・ Bed O' Roses ・ Bed O' Roses Handicap ・ Bed of Gold ・ Bed of Lies ・ Bed of Lies (film) ・ Bed of Lies (song) ・ Bed of nails ・ Bed of nails (disambiguation) ・ Bed of Nails (song) ・ Bed of Rose's ・ Bed of Rose's (album) ・ Bed of roses Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク Bed load ： ウィキペディア英語版 Bed load The term bed load or bedload describes particles in a flowing fluid (usually water) that are transported along the bed. Bed load is complementary to suspended load and wash load. Bed load moves by rolling, sliding, and/or saltating (hopping). Generally, bed load downstream will be smaller and more rounded than bed load upstream (a process known as downstream fining). This is due in part to attrition and abrasion which results from the stones colliding with each other and against the river channel, thus removing the rough texture (rounding) and reducing the size of the particles. However, selective transport of sediments also plays a role in relation to downstream fining: smaller-than average particles are more easily entrained than larger-than average particles, since the shear stress required to entrain a grain is linearly proportional to the diameter of the grain. However, the degree of size selectivity is restricted by the hiding effect described by Parker and Klingeman (1982), wherein larger particles protrude from the bed whereas small particles are shielded and hidden by larger particles, with the result that nearly all grain sizes become entrained at nearly the same shear stress. Experimental observations suggest that a uniform free-surface flow over a cohesion less plane bed is unable to entrain sediments below a critical value $\backslash tau\_$ of the ratio between measures of hydrodynamic(destabilizing) and gravitational(stabilizing) forces acting on sediment particles, the so-called Shields stress $\backslash tau\_$ *. This quantity reads as: :$\backslash tau\_$ *=\frac, where $u\_$ is the friction velocity, s is the relative particle density, d is an effective particle diameter which is entrained by the flow, and g is gravity. Meyer-Peter-Müller formula for the bed load capacity under equilibrium and uniform flow conditions states that the magnitude of the bed load flux $q\_s$ for unit width is proportional to the excess of shear stress with respect to a critical one $\backslash tau\_$. Specifically, $q\_s$ is a monotonically increasing nonlinear function of the excess Shields stress $\backslash phi(\backslash tau\_\; -\backslash tau\_\; )$, typically expressed in the form of a power law. . ==References== 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Bed load」の詳細全文を読む スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.