【正文】
Chapter 4 Energy flow in the agroecosystem 農(nóng)業(yè)生態(tài)系統(tǒng)的能量流 任何生命過(guò)程無(wú)不自始至終貫穿著能量、物質(zhì)和信息的有組織、有秩序的流動(dòng)。能量的輸入、傳遞、轉(zhuǎn)化、做功,是生態(tài)系統(tǒng)最重要的功能;農(nóng)業(yè)生態(tài)系統(tǒng)的能量流動(dòng),是體現(xiàn)農(nóng)業(yè)生產(chǎn)持續(xù)運(yùn)轉(zhuǎn)的基本過(guò)程。 The laws of thermodynamics describe the transformation of energy from one form to another ? The first law of thermodynamics deals with the conservation of energy, stating that one kind of energy may be transformed into another form, energy itself cannot be created or destroyed. ?熱力學(xué)第一定律認(rèn)為:一個(gè)系統(tǒng)的任何狀態(tài)的變化,都伴隨著吸熱、放熱和做功,而系統(tǒng)的總能量并不增加或減少,它是守恒的。即Δ E=Δ Q+Δ W。 Δ E表示系統(tǒng)內(nèi)能的變化, Δ Q表示系統(tǒng)吸熱或放熱, Δ W表示自身做功或系統(tǒng)對(duì)外做功。 熱力學(xué)第二定律(能量衰變定律) ?The second law of thermodynamics basically says that no energy transfer from one form to another is 100% efficient (often, the additional energy is lost as heat). ?由于總有一部分能量散發(fā)為不能再利用的熱能,能量從一種形態(tài)轉(zhuǎn)變?yōu)榱硪环N形態(tài)的效率,總不可能是百分之百。 Prigogine’ s dissipative struc