Weallknowthatthenormalhumandailycycleofactivityisofsome7-8hours'sleepalternatingwithsome16-17hours'wakefulnessandthat,broadlyspeaking,thesleepnormallycoincideswiththehoursofdarkness.Ourpresentconcerniswithhoweasilyandtowhatextentthiscyclecanbemodified.

　　我们都知道,正常人体每天活动的周期是大约7-8个小时睡眠和16-17个小时的清醒交替,从广义上讲,通常睡眠与夜间的时间相吻合.目前,我们关注的是如何轻松地,使这个周期可以修改到什么程度.Thequestionisnomereacademicone.Theease,forexample,withwhichpeoplecanchangefromworkinginthedaytowinkingatnightisaquestionofgrowingimportanceinindustrywhereautomationcallsforround-the-clockworkingofmachines.Itnormallytakesfromfivedaystooneweekforapersontoadapttoareversedroutineofsleependwakefulness,sleepingduringthedayendworkingatnight.Unfortunately,itisoftenthecaseinindustrythatshiftsarechangedeveryweek;apersonmayworkfrom12midnightto8a.m.oneweek,8a.m.to4p.m.thenext,and4p.m.to12midnightthethirdandsoon.Thismeansthatnosoonerhashegotusedtooneroutinethanhehastochangetoanother,sothatmuchofhistimeisspentneitherworkingnorsleepingveryefficiently.

　　现在的问题并非仅仅是个学术性的问题.例如,人们可以轻而易举把白天的工作改为晚上,因为在行业中的自动化机器要求二十四小时工作是日益重要的问题.一个人去适应黑夜白天颠倒通常需要五天到一个星期,白天睡觉夜间工作.不幸的是,行业中通常是每星期都改变班次.;一个人可能第一个星期是从午夜12时工作至上午8时,下个星期是上午8点到下午4点,第三个星期是下午4点至晚上12时等等.这意味着,他一习惯周期就又变了周期,从而使他大部分时间的花费在休息时和工作时的效率都很低.Oneanswerwouldseemtobelongerperiodsoneachshift,amonth,oreventhreemonths.RecentresearchbyBonjeroftheNetherlands,however,hasshowsthatpeopleonsuchsystemswillreverttotheirnormalhabitsofsleepandwakefulnessduringtheweek-endandthatthisisquiteenoughtodestroyanyadaptationtonightworkbuiltupduringtheweek.一个解决的方法似乎是较长换班次,一个月,甚至三个月或更长的时间.然而荷兰人Bonjer最近的研究表明,在周末期间人们靠如此方法将恢复到睡眠和醒的正常习惯并认为这足以摧毁在一周内建立的任何夜班工作的适应.

　　Shefoundahighincidenceofdisturbedsleep,digestivedisorderanddomesticdisruptionamongthoseonalternatingdayandnightshifts,butnoabnormaloccurrenceofthesesymptomsamongthoseonpermanentnightwork.

　　她发现在昼夜交替轮班中的那些人中睡眠不安、消化系统紊乱和家庭生活混乱出现率高,但这些症状在那些长期夜班的人身上无异常发生.

　　供参考大致翻译了一下