安修司电罗经drawing ver 1[1].0
磁罗经
简介罗经compass罗经是一种测定方向基准的仪器，用于确定航向和观测物标方位。
罗经分为磁罗经和电罗经两种，现代船舶通常都装有这两种罗经。
飞机上也装有罗经，航空用的罗经称为航空罗盘。
罗经磁罗经是利用磁针指北的特性而制成。
指南针即是原始型式的磁罗经，是中国古代四大发明之一。
用于航海的指南针又称罗盘。
铁船出现后，磁经产生了自差。
19世纪以后，先后提出消除自差的方法，至20世纪初，性能稳定、轴针摩擦更小的液体罗经制成，曾用于大部分船舶。
磁罗经有磁差，是由于地磁极与地极不一致而产生。
存在于磁北和真北之间的夹角，即磁偏角。
海图上标注有本地磁差和年变化率，使用磁罗经时可据以修正读数。
磁罗经结构主要由罗经柜和罗经盆组成，带有磁针的罗经卡安装在盆内。
电罗经罗经又称陀螺罗经，是利用陀螺仪的定轴性和进动性，结合地球自转矢量和重力矢量，用控制设备和阻尼设备制成以提供真北基准的仪器。
陀螺罗经是由主罗经与分罗经、电源变换器、控制箱和操纵箱等附属设备构成。
磁罗经发展历程磁罗经利用自由支持的磁针在地磁作用下稳定指北的特性而制成的罗经。
磁罗经由中国的司南、指南针逐步发展而成。
司南为天然磁石制成的勺形物，投转于光滑的地盘上,停止时勺柄指南。
地盘四周刻有八卦和天干地支名称，用于表示方位(图1)。
已知关于司南的最早记述见于公元前3世纪战国末期的《韩非子·有度》。
宋朝初期出现了人工磁化的指南针，有水浮、丝悬、针顶等方法，近代磁罗经和地磁测量仪器仍沿用这些基本结构。
北宋沈括在《梦溪笔谈》(1063年)中描述了用磁石磨针锋制作指南针的方法，并记载了磁差的存在。
指南针是初级阶段的磁罗经，是中国古代四大发明之一。
唐宋时期中国海外贸易非常发达，大型商船远航到波斯湾、红海等地，造船和航海技术均居世界前列。
指南针应用于航海的最早记载见于北宋朱彧的《萍州可谈》(1119年)，书中说:"舟师识地理,夜则观星,昼则观日，阴晦观指南针。
安许茨罗经1
二、电路系统
安许茨标准20型陀螺罗经的电路分为： 电源电路 随动系统 温控系统 信号检测系统。 电路系统除电源系统外，各种功能的实现都是由不同的传感 器检测输出不同的信号，由主控制器进行处理来实现。
1.电源系统 安许茨标准20型陀螺罗经的电源系统主要由： 直流稳压电路； 55V400Hz逆变器组成。
紧凑型配置：
组合型配置：
主要技术指标：
1.精度（accuracies）
稳定点误差（settle point error）
静态误差（static error） 动态误差（dynamic error）
≤±0.1°×secφ
≤±0.1°×secφ ≤±0ime）（精度在±0.2°之内）
由：随动传感器、放大器、AC/DC变换器、CPU、随动电机控制器和随动步 进电机等组成。
随动传感器是基于惠斯通电桥原理工作的信号电桥。 随动球上的随动电极和陀螺球上的赤道电极间的液体电阻R1，R2，组成信 号电桥的活动臂，对称变压器M1的初级绕组组成信号电桥的固定臂，电源由 55V400Hz陀螺电源供給。 当随动球与陀螺球在方位上出现偏 角时，两液体电阻R1和R2即出现差值， 信号电桥失去平衡，对称变压器次级 便输出与之对应的交流随动电压信号。 信号放大后变换成直流电压信号， 信号的大小约为0.5VDC/度。直流电 压输入到CPU的模/数转换端。 CPU把输入模拟信号变换成8位数字 信号，输至随动电机控制器。 随动电机控制器把数字信号变换成模拟控制信号，输出到随动步进电机的 两个绕组，随动电机转动，通过皮带带动方位齿轮，使整个随动部分转动， 直至随动球与陀螺球在方位上对准，随动信号消失，随动电机便停止转动。
3h
70°/s 150°/s 9600 baud 24VDC
Slovenské vzory dělení slov as pro změnu
Slovenskévzory dˇe leníslov:ˇc as pro zmˇe nu?Petr SojkaMasarykova univerzita v Brnˇe,Fakulta informatikyBotanická68a,60200BrnoEmail:sojka@fi.muni.czAbstrakt:Dˇe leníslov neboli algoritmickásegmentace velkémnožinyˇr e-tˇe zc˚u nˇe jakého jazyka je problémˇc astˇe jšínežby se na prvnípohled zdálo.Pro volnˇešiˇr itelnéslovenskédˇe leníslov zatím existuje pouzeˇr ešenívy-cházejícíz definice slabiky ve slovenštinˇe,bez rozsáhlého pokrytívýjimek.Z více nežmiliónu shromáždˇe ných a rozdˇe lených slov se podaˇr ilo vyge-nerovat programem P AT G EN novévolnˇešiˇr itelnévzory,kterése s nepra-videlnostmi jazyka vyrovnávajílépe neždosud dostupnéˇr ešení.Výsledekje použitelnýnejen v distribucích T E Xu,ale i v dalších systémech jako na-pˇríklad O PEN O .Použitéa diskutovanétechniky bootstrappingu,stratifikace a generovánívzor˚u jsou použitelnépˇr iˇr ešeníširokého spektradalších…segmentaˇc ních“aplikací.Klíˇc ováslova:dˇe leníslov,segmentace,P AT G EN,pˇr ebíjejícívzory,bootstrapping, stratifikace1MotivaceDˇe leníslov je v jádru všech aplikacípro zpracovánítext˚u.Na kvalitˇe použitého algoritmu dˇe leníslov závisímnožstvíruˇc nípráce pˇr iˇrádkovém zlomu sazby. Stáleˇc astˇe jšíjsou aplikace,kdy kontrola zlomu se neprovádív˚u bec:databázovépublikování,dávkovézpracováníXML dat m˚uže sloužit jako pˇríklad.O to vˇe tšíje poptávka po kvalitním dˇe leníslov.Obvyklépožadavky na algoritmus dˇe leníslov jsou tyto:rychlost:pˇr i optimalizaci zlomu celého odstavce naráz je potˇr eba najít dˇe lenívšech slov v odstavci.pˇr esnost:algoritmus neoznaˇcíchybnˇešvy slov pro rozdˇe lení.úplnost:algoritmus najde všechna možnádˇe leníslov.rozšiˇr itelnost:algoritmus umožníuživatelem specifikovanévýjimky–napˇrí-klad slova cizího jazyka dle pravidel dˇe lenítohoto jazyka.adaptivita:jelikožseživéjazyky vyvíjejí(nedávnáreforma pravopisu v Nˇe-mecku),je potˇr ebnénemít algoritmus…zadrátovaný“a draze optimalizo-vanýtak,že pˇr i zmˇe nˇe jazyka se musízaˇcínatúplnˇe znova.68Petr Sojkaparametrizovatelnost:algoritmus umožníjinéchovánídle charakteru použití(vúzkých sloupcích napˇríklad umožníjen dva znaky na novémˇrádku místo obvykležádaných tˇrí).minimálnípamˇe t’ovénároky:aplikace typu zalomenízpráv na displeji mobil-ního telefonu je tˇr eba navrhovat s minimálními pamˇe t’ovými,a tedy energe-tickými nároky.Základním problémem tedy je vytvoˇr it algoritmus pro zvolenýjazyk,kterýv maximálnímíˇr e splˇn uje výše uvedenépožadavky.Tentoˇc lánek popisuje pˇrístup ˇr ešenítohoto problému pro slovenštinu a krátce diskutuje výsledek ve formˇe nových vzor˚u dˇe leníslov pro slovenštinu.2Stávajícístav slovenského dˇe leníslovUživatelésázecího systému T E X používajípˇr i sazbˇe výsledky dizertaˇc nípráce[16]Knuthova studenta Franka Lianga.Liang navrhl na jazyku nezávislýpopis dˇe leníslov,kterýsplˇn uje vˇe tšinu výše uvedených požadavk˚u.Dále im-plementoval program P AT G EN[17],kterýumožˇn uje tento popis generovat ze slovníku jižrozdˇe lených slov.Brzy po rozšíˇr eníT E Xu doˇCeskoslovenska zaˇc ala být otázka dˇe leníaktuálnía vznikly prvníverze slovenských aˇc eských vzor˚u dˇe lení[14,15].Obˇe byly psány ruˇc nˇe,bez použitíprogramu P AT G EN.Ruˇc nˇe psanápravidla zachycujízákladnícharakteristiky dˇe lení,tedy napˇríklad slabiˇc nýprincip,definujíco je to slabika. U etymologického pˇrístupu k dˇe leníslov,kterýje respektován v britskéangliˇc tinˇe a standardizován nakladatelstvím Oxford Universitzy Press,však je témˇeˇr každéslovo výjimkou a proto jeˇc astˇe jšígenerovánívzor˚u ze slovníku.Vˇe tšina jazyk˚u však oba pˇrístupy kombinuje,ctíse zejména zlom našvech složených slov oproti slabiˇc nému principu.Hranice mezi cítˇe ním složeného slova dle jeho etymologie však m˚uže být diskutabilní:máme dˇe lit slabiˇc nˇe ro-zumˇc i…etymologicky“a konzervativnˇe roz-um?Pro detailnívysvˇe tleníprincipu pˇr ebíjejících vzor˚u odkazujeme na[13,pˇrí-loha H]a naˇc lánky[2,22,3].Zjednodušenˇeˇr eˇc eno,vzory specifikujíkontextovápravidla,kterámezi sebou soutˇežío každou mezipísmennou pozici ve slovˇe, a urˇc ují,zda na nídˇe litˇc i ne.Pravidla specifikujína základˇe r˚u znˇeširokého kontextu výjimky,výjimky z výjimek,....Vzájemnˇe se pˇr ebíjejí–m˚uže existovat nˇe kolikúrovnípriorit vynuceníˇc i potlaˇc enídˇe leníslova.Vítˇe zí…nejsilnˇe jší“pra-vidlo(s nejvyššíprioritou)pro každou pozici ve slovˇe:k pozici se m˚uže vyjádˇr it pravidlo v každéúrovni.Stávajícíverze slovenských vzor˚u dˇe leníexistuje ve verzi2.0z24.4.1992 (soubor skhyph.tex):\patterns{%samohl\’asky a1\’a1\"a1e1...%dvojice spoluhl\’asokSlovenskévzory dˇe leníslov:ˇc as pro zmˇe nu?692b1b2b1c2b1\v c2b1d2b1\v d...%6spoluhl\’asok3c4v4r4n3g4n3\v s4k4v4r4k3n3\v s4k4v4\’r4k3n%koncovka-n\’yk4\v c3n\’y.k4\v c3n\’eho.k4\v c3n\’emu.k4\v c3nom.%slovn\’e z\’aklady 5alkoholauto4rkauto4rs5b4lah5b4ledn 5b4lesk...%koncovky4b4s4\v t.8c4h.8d4z.8d4\v z.4c4ht4.4j4s4\v t.4lt.4m4p4r....%cudzie slov\’a akci3a2akv\’ari3u2m gymn\’azi3umle2u3k\’emiat2ri3u2mfkli3e2nt}Z komentáˇr˚u ve vzorech je vidˇe t,jakým zp˚u sobem vzory vznikaly.Po rozge-nerovánívzor˚u popisujících slabiku jako sekvenci pˇríslušného poˇc tu souhlásek a samohlásek se vzory autorka snažila zachytit slabiˇc névýjimky na zaˇcátku a konci slov a pˇr i dˇe lenícizích slov.Lze si ale tˇežko pˇr edstavit,že by se tímto zp˚u sobem podaˇr ilo zachytit nˇe kolik milión˚u slovních tvar˚u,kteréve slovenštinˇe existují. Našvech pˇr edpon a složených slov jsou mnohévýjimky,kteréjdou proti základ-nímu slabiˇc nému principu.Tˇe ch jsou ale tisíce,ˇc i desetitisíce,a jen s enormním úsilím by se daly vypsat všechny.Proˇc eštinu byly sepsány Hallerem[10],pro slovenštinu však patrnˇe takovýsoupis neexistuje.Na archívu CTAN lze nalézt vzory vytváˇr enéjak ruˇc nˇe výše popsaným zp˚u sobem,tak automaticky z jižrozdˇe leného slovníku slov daného jazyka.Tento postup máz hlediska požadavk˚u vytˇc ených vúvoduˇc lánku mnohévýhody oproti ruˇc nˇe vytvoˇr enéverzi.Pˇrístupy se takédajíkombinovat:k ruˇc nˇe zadanémnožinˇe základních vzor˚u se dogenerujívzory pro výjimky.Nebo naopak ex post nalezenévýjimky se dajík jižvygenerovaným vzor˚u m pˇr idat jako slova–vzory s nejvyššíprioritou(úrovní),tedy rozum jako.r8o8z9u8m..3Generovánívzor˚u ze slovníku rozdˇe lených slov Problematice generovánívzor˚u na semináˇr i S L T jižbyl vˇe novánˇc lánek[1],proto zopakujeme jen hlavníprincipy a laskavéhoˇc tenáˇr e odkážeme dále na dalšíˇc lánky vˇe novanététo a pˇríbuznéproblematice[11,25,20,21].Generováníprobíháve fázích,kterése nazývajíúrovnˇe(anglicky levels). V lichýchúrovních se generujípokrývacívzory,tedy vzory,kterédle kontextu znak˚u vynucujídˇe lení,v sudýchúrovních se dˇe lenídle kontextu zakazuje.70Petr SojkaGenerovanévzory se kumulují,a výslednéchováníurˇc uje výslednámnožina vzor˚u vygenerovanáve všechúrovních.U vˇe tšiny generovaných vzor˚u pro dˇe leníslov v užívaných jazycích staˇcíˇc tyˇr iúrovnˇe,ale pro pˇr ehlednost,ale takénedostatekˇc asu vzory optimalizovat,je v ruˇc nˇe chystaných vzorechúrovnímnohem více–souˇc asnéslovenskévzory jich majínapˇríklad osm.Technologie pˇr ebíjejících vzor˚u je natolik obecná,že jejípoužitíje možnépro vˇe tšinu segmentaˇc ních problém˚u.Jako pˇríklad m˚uže sloužit problematika segmentaceˇr etˇe zce thajských znak˚u na slova–v thajském textu nejsou slova oddˇe lena mezerami[23].4Bootstrapping a stratifikaceV rámci bakaláˇr sképráce[18]se podaˇr ilo shromáždit z r˚u zných zdroj˚u1 témˇeˇr milión slovenských slov.Dnešnívýpoˇc etníkapacity umožˇn ujígenerovat vzory dˇe leníi z takto rozsáhlých slovník˚u v dobách desítek minut.ˇCasovˇe nejnároˇc nˇe jšíoperaci–rozdˇe leníslovníku slov pravidly daného jazyka–lze dˇe lat pomocípˇr edchozíverze vzor˚u a místa dˇe leníslov…pouze“zkontrolovat.Jelikožvšak i tato kontrola jeˇc asovˇe nároˇc ná,lze parametry generovánívhodnou heuristikou volit tak,že vygenerovaných vzor˚u nepokrytých slov je právˇe tolik, kolik je reálnéjich v rozumnédobˇe ruˇc nˇe zkontrolovat.To znaˇc nˇe urychluje vývoj nových vzor˚u technikou bootstrappingu.Tabulka1.Výsledky jednéiterace bootstrappingu slovenského dˇe leníze slov-níku822878slovúroveˇn dobˇr ešpatnˇe chybí#vzor˚u velikost1Bohužel výslednou množinu slov nelze volnˇešíˇr it.Volnˇe pˇrístupnýseznam slov by umožnil ještˇe mnohemflexibilnˇe jšívytváˇr enívariant dˇe licích vzor˚u optimalizovaných pro konkrétníprojekty.Slovenskévzory dˇe leníslov:ˇc as pro zmˇe nu?71 ještˇe v tomto stoletíjedno celéˇcísloˇc asopisu TUG BOAT.Patrnˇe z d˚u vodu zpˇe tnékompatibility nejsou tyto vzory nahrazeny kvalitnˇe jšími,byt’kompatibilita je pˇr i pˇr idánívýjimek do vzor˚u ve formátu stejnˇe porušena.Dnešnívýpoˇc etnítech-nika jižumožˇn ujeˇc etnéexperimenty a generováníopakovat s r˚u znými parame-try.Vhodnými heuristikami nastaveníprah˚u akceptace adept˚u vzor˚u v jednotli-výchúrovních generováníse lze dostat na mnohem kvalitativnˇe vyššíparametry vzor˚u,nežkterédocílil pˇr ed témˇeˇrˇc tvrtstoletím Liang.Typicky je možnéza cenu mírného zvýšenívelikosti vzor˚u docílit stoprocentního pokrytíuˇcícímnožiny, nebo naopak pˇr i zadánívelikostních omezenína velikost vzor˚u lze maximalizo-vat pokrytí.A to vše s nulovou chybovostía stejnými konstantními výpoˇc etními nároky pˇr i aplikaci vzor˚u.Jinakˇr eˇc eno,poˇc et instrukcína nalezenídˇe licíchšv˚u slova je ohraniˇc en shora konstantou,nezávisle na tom,z jak velkého slovníku vzory generujeme.Dalšítechnikou,kteráse dápˇr i generovánívzor˚u použít,je stratifikace.Tato technika spoˇcíváv tom,že se snažíme minimalizovat množinu slov k uˇc ení, anižbychom ale pˇr išli o funkˇc nost vzor˚u na výjimkách.Máme-li napˇríklad slovník generovanýmorfologickým analyzátorem,tedy známe od každého slovního tvaru slovnízáklad,staˇcído slovníku slov zahrnout náhodnˇe pouze pár slovních tvar˚u od jednoho lemmatu.Dˇe leníkoncovek se zgeneralizuje,nebot’koncovkovémnožiny se neustále opakujía uˇcícíalgoritmus bude mít dostatek uˇcících pˇríklad˚u,aby se pravidelnosti dˇe leníkonc˚u slov nauˇc il.Naopak se nesmív seznamu uˇcících slov zapomenout na negace a pˇr edpony.Dˇe leníza prvníslabikou slov zaˇcínajících na na-naj-,pre-pred-apod.je nutno nahlížet jako na výjimky.5Shrnutí:ˇc as pro zmˇe nu?Bylo vytvoˇr eno nˇe kolik variant nových vzor˚u dˇe lenípro slovenštinu.Vzory jsou pro testováník dispozici ve FTP archívu CSTUGu v adresáˇr i cstug/sojka/skhyp. Po nezbytnéfázi testovánípˇr edpokládáme jejich zaˇr azenído bˇežných T E Xových distribucía projektu O PEN O a budoušíˇr eny bez omezujících licenˇc-ních podmínek.Jelikožzmˇe na vzor˚u dˇe lenípravdˇe podobnˇe zp˚u sobízmˇe nu zalomeníjižvytvoˇr ených dokument˚u,je tˇr eba být v pˇrípadˇe rozšíˇr eného požadavku na zpˇe tnou kompatibilitu obezˇr etný.Jelikožna zálohováníúplných zdroj˚u vˇc etnˇe zdroj˚u potˇr ebných na generováníformátu se obvykle zapomíná,pˇr i požadavku zpˇe tnékompatibility je tˇr eba zvážit všechna pro i proti a novévzory si tˇr eba zavést jako novýjazyk(\language)spolu se starými.Jsme pˇr esvˇe dˇc ení,žeˇc as pro zmˇe nu po více neždekádˇe používánísouˇc asných vzor˚u nastal a kvalita nových vzor˚u je dostateˇc ným argumentem pro zavedenízmˇe ny.Po téjižostatnˇe nˇe kolik let volajítakéuživateléO PEN O a dalších sázecích systém˚u, kteˇrídosud používajístarévzory dˇe lení.72Petr SojkaReference1.David Antoša Petr Sojka.Generovánívzor˚u dˇe leníslov v UNICODE.V Kasprzak aSojka[12],strany23–32.2.David Antoša Petr Sojka.Pattern Generation Revisited.V Pepping[19],strany7–17.3.David Antoša Petr Sojka.Generovánívzor˚u pomocíknihovny P AT L IB a programuOP AT G EN.Zpravodaj C S TUG,12(1):3–12,2002.4.Barbara Beeton.Hyphenation exception log.TUGboat,5(1):15,kvˇe ten1984.5.Barbara Beeton.Hyphenation exception log.TUGboat,6(3):121,listopad1985.6.Barbara Beeton.Hyphenation exception log.TUGboat,7(3):146–147,ˇríjen1986.7.Barbara Beeton.Hyphenation exception log.TUGboat,10(3):336–341,listopad1989.8.Barbara Beeton.Hyphenation exception log.TUGboat,13(4):452–457,prosinec1992.9.Pat Hall a Durgesh D Rao,editoˇr i.Proceedings of EACL2003Workshop onComputational Linguistics for South Asian Languages–Expanding Synergies with Europe,duben2003.10.JiˇríHaller.Jak se dˇe líslova.StátnípedagogickénakladatelstvíPraha,1956.11.Yannis Haralambous.A Small Tutorial on the Multilingual Features of PATGEN2.dostupnéna CTAN jako info/patgen2.tutorial,leden1994.12.Jan Kasprzak a Petr Sojka,editoˇr i.SLT2001,Brno,Czech Republic,únor2001.Konvoj.13.Donald E.Knuth.The T E Xbook,volume A of Computers and Typesetting.Addison-Wes-ley,Reading,MA,USA,1986.14.Jana Chlebíková.Ako rozdˇe lit’(slovo)ˇCeskoslovensko.Zpravodaj C S TUG,1(4):10–13,1991.dislav Lhotka.ˇCeskédˇe lenípro T E X.Zpravodaj C S TUG,1(4):10–13,1991.16.Franklin M.Liang.Word Hy-phen-a-tion by Com-put-er.PhD thesis,Department ofComputer Science,Stanford University,USA,srpen1983.17.Franklin M.Liang a Peter Breitenlohner.PAT tern GEN eration program for the T E X82hyphenator.dokumentace programu PATGEN verze2.3z distribuce web2c na CTAN, 1999.18.Ján Lieskovský.Systém pro práci se seznamy slov.Bakaláˇr skápráce,Masarykovauniverzita v Brnˇe,Fakulta informatiky,2003.19.Simon Pepping,editor.EuroT E X2001,Kerkrade,The Netherlands,záˇrí2001.NTG.20.Petr Sojka.Notes on Compound Word Hyphenation in T E X.TUGboat,16(3):290–297,1995.21.Petr Sojka.Hyphenation on Demand.TUGboat,20(3):241–247,1999.22.Petr peting Patterns for Language Engineering.V Sojka et al.[24],strany157–162.23.Petr Sojka a David Antoš.Context Sensitive Pattern Based Segmentation:A ThaiChallenge.V Hall a Rao[9].24.Petr Sojka,Ivan Kopeˇc ek,a Karel Pala,editoˇr i.Proceedings of the Third InternationalWorkshop on Text,Speech and Dialogue—TSD2000,Lecture Notes in Artificial Intelligence LNCS/LNAI1902,Brno,záˇrí2000.Springer-Verlag.25.Petr Sojka a PavelŠeveˇc ek.Hyphenation in T E X–Quo Vadis?TUGboat,16(3):280–289,1995.。
电罗经
电罗经是根据陀螺原理制成的，根据陀螺在不受外力的作用下，保持空间指向不变的原理，制作成电罗经，电罗经的标准学名是陀螺罗经，只不过用电，大家就叫它电罗经。
陀螺罗经在启动的时候，其指针指北，之后便一直指北，如果偏离指北，在重力的作用下，自动修正指北。
根据陀螺马达数量及支撑马达的系统分为三大系列。
分别是安修斯，斯伯列，阿芒.勃朗。
一个陀螺马达及液体支撑马达的是安修斯，两个陀螺马达（马达轴向成直角）及液体支撑马达的是斯伯列，一个马达及没有液体支撑的是阿芒.勃朗。
不管什么牌子、什么型号，基本上是参照这三个系列来制造。
电罗经不受磁场的影响，但只能在南北纬70度以内使用，南北两极就不能使用。
关于电罗经和磁罗经电罗经（GYROCOMPASS）有主罗经（mast gyro）、分罗经（repeater）、控制箱（control unit）以及航向记录仪（course recorder）组成。
由于船舶电罗经和自动舵基本都是配套由同一个厂家提供，主罗经的安放位置一般有如下几种方式。
1。
内置式主罗经build-in自动舵内。
控制箱可以拆分后同样安装在自动舵内主罗经两侧，或者安装在驾驶室后壁。
2。
放在专门罗经房主罗经放在专用罗经房内。
罗经房一般在驾驶台同层或者下一层居多。
有甚者在下两层。
3。
分离式主罗经放置在报房或者驾控台内部（一般这种情况，大多数自动舵也为分离式）。
现今常见的电罗经产品：1。
日本产yokogawa cmz-xxx x系列（xxx表数字，如500，700，后一个x表类别，s表单套，d表双套）。
陀螺球浮于专用液体中。
液体由苯甲酸，甘油，蒸馏水按照3.2g，145ml，1.6l配比混合。
2。
日本产tokimec TG-XXXX x系列（x表意同前）。
干球，无液体。
3。
德国产retheon anschtuz std-xx （x表意同前）系列。
陀螺球浮于专用液体中。
配方记不住就不写了。
4。
其他如c-plath，sperry等产品相对来说用的和见的都比较少。
《罗经、测深仪》课件
罗经的主要作用是确定航向，提 供方向信息，帮助航行者规划航 线，确保安全、准确地到达目的 地。
罗经的种类与特点
磁罗经
磁罗经是最常见的罗经类型，它 利用地球磁场来确定方向。磁罗 经具有结构简单、使用方便、可 靠性高等优点，但易受磁场干扰
，需要定期校准。
陀螺罗经
陀螺罗经是一种基于陀螺仪原理 的罗经，它不受磁场干扰，精度 高，稳定性好，但价格昂贵，维
护成本高。
电罗经
电罗经采用电子传感器来测量方 向，具有精度高、稳定性好、抗 干扰能力强等优点，但需要电源
供电，且价格较高。
罗经的历史与发展
罗经的历史
罗经的发展可以追溯到古代，最早的磁性指南针是中国人发 明的，用于航海导航。后来，欧洲人也开始使用磁性指南针 进行导航。随着科技的发展，现代罗经不断涌现，成为船舶 、飞机等航行的重要工具。
环境保护
通过罗经和测深仪的测量 数据，可以更好地监测和 保护海洋环境。
面临的挑战与机遇
技术更新换代
随着技术的快速发展，罗经和测 深仪需要不断更新换代，以满足
市场需求。
市场竞争
市场竞争激烈，需要不断提高产品 质量和服务水平。
政策支持
政府对海洋产业的支持将为罗经和 测深仪的发展带来机遇。
谢谢
THANKS
《罗经、测深仪》ppt课件
目录
CONTENTS
• 罗经简介 • 测深仪简介 • 罗经与测深仪的比较 • 罗经与测深仪的应用案例 • 未来展望
01 罗经简介
CHAPTER
罗经的定义与作用
罗经的定义
罗经是一种导航工具，用于确定 方向和航向。它通过测量地球磁 场的方向来工作，为船舶、飞机 等提供准确的导航信息。
01第罗经二章第一节(ppt文档)
二、磁铁（magnets）
磁性，物体吸引铁镍等物质的性质。 磁极：磁铁磁性最强处，磁极距端点处
为L/12，磁量|-m|=|+m|。
L/12
L/12
S
l
-m
l
N
+m
L
磁距(moment)：表示磁铁磁性的强弱。
M＝2lm （磁矩单位CGSM） 磁铁磁距为同名磁量与两磁极间距的乘积。
H = m/r2 (奥) 磁场强度是一矢量，指向磁力线的切线方向。
磁感应强度B： 磁后感 产应 生强 的度 附等 加于 磁磁场H场´的之场和强，H即º和铁磁体被磁化
B = Hº+ H´ （高Gs）（国际单位制T） B = µH µ—磁导率 均匀磁场 若在一定范围内各点的场强大小相等，方向平 行则称此范围内的磁场为均匀磁场。
航海仪器
主讲教师 王兵玲
第二章 船用磁罗经
• 磁罗经定义：利用地磁场对磁针具有吸引力
的现象而制成的一种航海指向仪器。（在罗 盘磁针与地磁场相互作用下，罗盘能指向磁 北极的航海指向仪器。）
• 特点：结构简单，性能可靠，不依赖任何外
界条件可独立工作。但受船磁场的影响，罗 盘偏离磁北会产生自差。
• 磁罗经作用：指向及定位，与陀螺罗经一起， 相辅相成，保证船舶安全航行
船用磁罗经
第一节、磁的基础知识 第二节、船用磁罗经 第三节、磁罗经的检查、保管与安装 第四节、船正平时的自差理论 第五节、倾斜自差理论 第六节、磁罗经自差校正 第七节、自差的测定和自差表计算
一 、磁基本概念
两磁极间的作用力 F（库仑定律）
F m1
m2 F
《大唐西域记》的文学归属
的传说旅行记”a。这些观点均认同《大唐西域记》是文学性较强的行记，可列 入游记之中。
但对什么是游记文学，专门的探讨并不多。2009年版的《辞海》给游记下了 一个较为通俗和全面的定义，“散文的一种。主要记述旅途见闻，某地历史沿 革、现实状况、社会习尚、风土人情和山川景物、名胜古迹等，也表达作者的 思想感情。文笔轻快，描写生动。”b王立群和梅新林也曾对游记文体的构成要 素进行了分析，前者认为，游踪、景观和情感是构成游记文体的三个要素c，后 者则将其概括为所至、所见和所感（即游程、游观和游感）d。玄奘在《大唐西 域记》的“序”中，自言这部作品“辄随游至，举其风土”e，是对自身行经中 亚、南亚地区的地理、史事、宗教、语言、民俗、风土等进行的亲忆亲述。辩机 所作的“记赞”中也说此书“境路盘纡，疆场回互，行次即书”f，即基本以行 经路线为序进行记载的。此外，作品文学色彩浓郁，作者的情感虽不外露，但潜 隐于对佛国圣迹进行朝圣描摹的字里行间。在此意义上，将《大唐西域记》归入 游记文学，是有其合理性的。
c 慧立、彦悰著，孙毓棠、谢方点校：《大慈恩寺三藏法师传》，中华书局 2000 年版，第 1 页。
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d 梅新林、俞樟华主编：《中国游记文学史》，学林出版社 2004 年版，第 81 页。
e-陈µ佳荣¶、Î钱Ï江、(张ì广d达e编：ñ《5历!代中f外g行S纪》K，ì上d海辞2书.出Ö版Z社 2[0028 年µ版¶，第S1Ì43~$16h8 页ð。2e
航海仪器课件：陀螺仪的概念和特性
（2）作用：判断罗经性能的好坏。（若从阻尼曲线中量取的 阻尼因数和阻尼运动周期与说明书中相差很大时，说明罗经性能 已不符合设计要求，应向主管部门报告要求维修或更换）
3．下重式罗经的阻尼运动轨迹
图1－29
五、主轴视运动线速度
图1－18
自由陀螺仪的视运动 (回顾)
[特殊位置] 1．把自仪放在赤道上，若主轴一开始就指北，则以后一
直指北。
2．位于地极上自仪的视运动——高度角 不变、方位角 （水平角） 不断发生变化。
*[一般位置] 1．由于ωe 的垂直分量使子午面（真北线）转动、北纬真
北线北端Ｎ西偏，而北纬某点的自仪主轴指北端方向不 变，所以在地球人看来轴北端东偏。
自由陀螺仪不能指北的矛盾 :
•主轴指北端的升降运动----------------------------------V1 •主轴指北端的水平偏移运动（ω2的影响）---------V2 亦即“北纬东偏，南纬西偏”是主要矛盾 解决方法:施加控制力矩 施加控制力矩的要求: •自动产生，根据进动的需要，大小和方向都要合适 •应能随纬度的变化，自动的进行调整
二.陀螺仪的特性(1)
[定轴性]1.定义二:不.陀受外螺力仪矩作的用特的3性自由(1度)平衡陀螺仪的
主轴将保持其在宇宙空间的初始方向不变。
2.表现:A 太空人的感觉 B 敲击 C 摇晃基座
二.陀螺仪的特性(2)
[进动性](图) 1.角速度 2.动量矩 3.外力矩 ☞4.定义 :在外力矩M的作用下，主轴动量矩
第四章 陀螺罗经 （电罗经）
陀螺罗经介绍
航海罗经是用来指示船舶航向和测定物标方位的仪器，作为航海罗 经使用，由于船舶不仅要经常转向，同时还会受到风浪的影响而振 动，因此航海罗经需满足下列要求：
航海学讲义之电罗经
（1）定轴性(gyroscopic intertia)
比对实验说明
定轴性：高速旋转的自由陀螺仪，当不受外力矩作用时，其主轴将保持它在空间的初始方向不变。
定轴性条件：陀螺转子高速旋转；陀螺仪不受外力矩作用。
定轴性表现特征：主轴指向空间初始方向不变。
（2）进动性(gyroscopic precession)
理想自由摆动周期所对应的纬度称为陀螺罗经的设计纬度(chosen latitude)（0），设计纬度是设计罗经时所选取的一特殊纬度。例如安许茨4型罗经的设计纬度为60°。
4.使陀螺罗经稳定指北
1）使陀螺罗经稳定指北的措施
阻尼力矩(damping moment)：为了使陀螺罗经稳定指北而对陀螺仪施加的力矩。
阻尼设备(damper))（阻尼器）：陀螺罗经产生阻尼力矩的设备（器件）。
阻尼方式(damping mode)：陀螺罗经将阻尼力矩施加在陀螺仪（球）的哪一轴上
陀螺罗经的阻尼方式：水平轴阻尼方式(damping mode of horizotal axis)和垂直轴阻尼方式(damping dode of vertical axis)。
My=mgsin·a
≈mg a·
=M·
M=mga最大控制力矩
控制力矩的大小与罗经结构参数和主轴高度角有关
控制力矩M使主轴产生进动速度u2，它使主轴正端自动找北（向子午面进动）。
根据赖柴尔定理：动量矩H矢端的线速度矢量与外力矩矢量M大小相等方向相同：
=M
陀螺罗经控制力矩M使罗经主轴产生的进动速度：
2=M=M·
自由陀螺仪进动特性口诀：
陀螺仪表定向好，
进动特性最重要，
要问进动何处去？
About Flash................................................................................
Production of multimedia content using FlashDepartment of Electronics and Computer Science, University of Southampton1. AbstractMacromedia Flash is one of the most powerful web authoring tools available to web designers today and is used to produce animated and still graphics. However, because of the poor use of Flash animations on the Internet, Flash has acquired a reputation for poor usability. Macromedia itself Macromedia itself and other individuals have produced tools and documentation to help designers make the most out of Flash have now published many usability tips. If these are followed, good multimedia content can be produced which is usable to others.ContentsKeywords ............................................................................................. 1 Introduction .......................................................................................... 1 Background .......................................................................................... 2 Research.............................................................................................. 2 About Flash ..................................................................................... 3 Flash Usability ................................................................................. 3 Alternatives to Flash........................................................................ 4 My Film ............................................................................................ 4 Conclusions.......................................................................................... 9 References......................................................................................... 102. KeywordsMacromedia Flash, Multimedia Content Creation, Animation Graphics, Sound, Video,3. IntroductionThe aim of this paper is to look at multimedia content produced by Macromedia Flash. Flash has become very popular over the past few years; 474 million Internet users use it today. In this paper I research into how Flash is used by developers today and why to give a background into the use of Flash. The advantages and disadvantages of Flash as a multimedia content creation tool are discussed to help developers to decide if Flash is a suitable tool for their project. A number of usability tips for Flash have been put together by a number of individuals, which it is recommended to follow if a usable Flash application is to1be made. I will research into these and outline them. I will also research briefly into alternatives to Flash. To fully understand how to create multimedia applications with Flash, I made a small movie of my own in Flash. I will describe the nature of my film and how it was created. Finally, I will evaluate my film and report my findings and give a summary of my experiences using Macromedia Flash.4. BackgroundFlash was first introduced in 1996 and was known as FutureSplash Animator and run by a company called FutureWave. It was used to play back animation on web browsers through Java. The company decided to sell off their technology due to financial difficulties, they tried Adobe who turned them down, but were soon bought by Macromedia. FutureSplash Animator became Macromedia Flash 1.0. There are 2 main components to the Flash software, which are: • Flash Editor – which is used to create the graphics and animation that make up the end movie • Plug-in or Flash Player – which is used by web-browsers to display the Flash movie Flash can be used to create movies, which incorporate graphics, sound and animation. These movies are generally placed on web sites on the Internet. The main reason web designers use Flash is because it provides a good online user interface, allowing visitors to interact with a web site. Also, animation is known to have a tremendous effect on human peripheral vision and therefore is a good way to relay information to people. Unfortunately, bad use of Flash on web sites has left Flash with a tarnished reputation. Most people either love it or hate it. Even though Flash is very popular on the Internet, many people find the Flash content unusable and annoying. The main arguments for Flash content being unusable are as follows: • The majority of Flash content is unnecessary and gratuitous • Content is usually built once and then not updated regularly • Content usually follows the established standards for Web content5. ResearchFirstly, it is important to look at reasons why and why not to use Flash as a way of conveying information on the Internet. These reasons are outlined below. Advantages of using Flash: • Flash films are browser independent; therefore they can be viewed with any browser, so is not limited. • Designers are able to control colours, fonts and resolution quality, and so can make their films to their needs. • As vector graphics are used, films can be scaled without it affecting the image resolution and objects will be smaller than their bitmap equivalents.2• •Animated and interactive films can be produced with sound, which will be more appealing to visitors, and get information across more easily. Flash software is very powerful, well supported and updated frequently.Disadvantages of using Flash: • Flash is quite a hard piece of software to learn, it may take developers a significant amount of time to learn to use the flash development environment • A plug-in is required to view Flash films, so not all machines will be able to view Flash films. • Flash does not have a user-friendly interface and it not intuitive for designers, and therefore might take designers longer to produce multimedia content. • Printing Flash movies results in poor text quality. • Search engines are unable to read Flash movies, so they do not show up. • It takes longer to create a Flash website than the usual HTML ones.About Flash Flash files have the .SWF extension. These files combine code, media and data into a format that is compact. These are loaded using a steaming model, where the first few frames become available to view once. The files are also cached, so that they can be retrieved again locally, saving time. Video and audio are streamed, which means that MP3 content can be dynamically loaded and player, and that full-motion films can be added. The Sorenson Spark Codec is used for high quality playback with low bandwidth. Flash uses a compressing/decompressing model to help lower network costs. Developers can compress their code when publishing the movie, and when a user wants to run this, it is decompressed on the user’s machine at runtime. Flash Usability One of the main problems with Flash is that it is known to have poor usability. Some usability tips have been produced by individuals. Macromedia’s Flash Usability tips: [/software/flash/productinfo/usability/tips/] • Remember user goals • Remember site goals • Avoid unnecessary intros • Provide logical navigation and interactivity • Design for consistency • Don’t overuse animation • Use sound sparingly • Target low-bandwidth users • Design for accessibility • Test for usability3Alternatives to Flash Flash is not the only development tool available to create multimedia content. A brief discussion of alternatives is presented below. Synchronized Multimedia Integration Language (SMIL) – this is a mark-up language (XML) which is used to write interactive multimedia content. Developers can define the temporal behaviour of their content and the layout of this on screen. Video and audio can be streamed with together with other media types. Scalable Vector Graphics (SVG) – this is a language used to describe two dimensional vector based graphics. It allows for images, text and vector and vector graphic shapes. The Document Object Model (DOM) includes full XML DOM, which allows for effective vector animation via scripting. My Film I used Macromedia Flash to create a small animated film which is to be placed on my university website. I had only ever encountered these types of films on the Internet, but never made one of my own. I also had never used Flash before, so it was a new experience. My film is titled “How to Turn a Geek into a Super Stud”, and shows through animated and still graphics how you can make a geek into a super stud! It can be viewed at /~mkg100 There are some important concepts that need to be understood before starting with Flash, these are described below. • SYMBOLS – these are graphics that have been created by using the drawing tools, and can be used over and over again within the film. • LAYERS – these can be thought of as transparent sheets that are placed on top of each other. Objects can be drawn on one layer without affecting objects in other layers. • FRAMES – displays the contents of I second of the film; a film is made of a series of frames. • KEYFRAMES – these are frames where changes in animation occur. The first frame in a frame is automatically a keyframe. • TIMELINE – shows the frames in all the layers of the film, and what events are occurring in the frames. The film starts of with the opening screen which shows the title, with a moving flashy yellow border, and a button, which when pressed will start the main part of the film. These three objects are placed in their own layers (I made a new layer for each). To place the title on screen, I created a layer called text (Insert ! Layer) and had to use the Text tool from the drawing tools, which works pretty much the same way as the ones found in other programs. You just have to enter the required text into the4box, and change the font size, type and alignment, as you so please. I also inserted a keyframe at frame 25 (Insert ! Keyframe), as this is the last frame that the text appears in. To insert the keyframe, you have to have that particular frame selected from the timeline. I created a new layer for the yellow flashy border, which was created by using keyframes and motion tweening. Motion tweening is used to change the size of objects or rotate them in an animated manner. I placed a keyframe every 5 frames, up to frame 25, and changed the size of the border in each one by transforming the shape (Window ! Inspectors ! Transform), or you could use the re-size option in the drawing tools to change the size. I then inserted the motion tween in each keyframe (Insert ! Create Motion Tween), which makes the border move from one size to the other. These 25 frames run continuously until the arrow button is pressed. This was achieved by selecting frame 25 in this layer and modifying the frame properties (Modify ! Frame ! Actions tab). I added a ‘Go to’ action and specified the frame to ‘go to and play’ scene 1, frame 1; the beginning of the film. The red arrow was also created in another layer, using the drawing tools, and was then turned into a button (Insert ! Convert to Symbol ! Button). When the cursor is placed over the button, the arrow increases in size. To do this you have to select the arrow button and then edit the object (Edit ! Edit Selected). This brings up a new scene with just the button in it. The timeline at the top of the screen has frames for ‘up’, ‘down’, ‘over’ and ‘hit’. You need to edit the button design in each frame depending on what you want the button to do when the corresponding actions occur. In this case, in the ‘over’ frame I drew an enlarged arrow by using the re-size tool. When the arrow button is pressed, the film jumps to the next screen, which starts in frame 30. The button performs this action by editing the buttons properties (Modify ! Instance ! Actions tab). I added a ‘Go to’ action and specified the frame ‘go to and play’ at as frame 30. Again I added a keyframe at frame 25, as this is the last frame for the arrow. There is another layer in this screen, which displays the background. In this instance the layer is empty as the background is white. The next scene shows the geek and ‘Mandy’s Geek Transformer’ machine, which starts from frame 30. The background is now a sea blue colour, which I created by drawing a large box with the drawing tools to fill the screen. The background layer must be the layer at the bottom so that all the other objects can be place on top of it. I created a new layer for the geek and placed a keyframe at frame 30. In this frame I used the drawing tools to create the geek. I then used drawing tools to create the speech bubble and then added a text box inside this to add the words. I also wanted some to be played at this frame; the geek saying “hello, my names Colin”. I had recorded some voices earlier with my microphone onto my5computer. I then imported this sound into Flash (File ! Import ! select sound file). I wanted the sound to be played at frame 30, so created a new layer for this sound. I then edited the frame properties to play the required sound file (Modify ! Frame ! Sound tab ! select file from drop down box) at this frame. Then I added another keyframe at frame 45, as this is the frame in which the transformer machine enters the film. I wanted the film to stop here until the button on the machine is pressed. Therefore, I set an action to frame 45 in the geek layer called ‘Stop’. This causes the film to stop at that frame until another event is triggered; in this case, the red button on the machine is selected. The machine is also drawn in a new layer and is created with the drawing tools. The title is drawn using the text facility. The red circle on the machine is a button whose action is to ‘go to and play’ at frame 50. At frame 50, I placed keyframes in the geek layer and the machine layer, as I wanted the objects in this layer to be displayed on screen but I deleted the geek’s speech bubble, as it was no longer required. I then created another layer, which starts at frame 50. This layer contains the rays that shoot out of the machine when the button is pressed and the ‘zap’ graphic. I drew the rays and zap with the drawing tools and then inserted another keyframe in this layer 3 frames down, frame 53, and used the re-size tool to reduce the size of the rays. I then used motion tweening to make the ray’s change in size on an animated way. I repeated this until frame 71, increasing and decreasing the size of the rays each time, with motion tweening between each. This was to give a shooting rays effect. I moved the ‘zap’ graphic in each of these keyframes as well with the aid of the arrow tool from the drawing tools. During the zapping, the geek shouts “Nooo!” which occurs from frame 50 to frame 82. Again I used the drawing tools to create this.After the zapping has finished the film has reached frame 83. The layer that contains the machine is no longer needed, so there are no frames for this layer anymore. In the geek layer, the geek has a speech bubble beside him, which was made by the drawing tools. The only layers active at this point are the one with the geek in it and the background.6Now the geek transformation begins!In this scene, which starts at frame 98, I entered a keyframe and deleted the glasses from the geek and added a text box, both changes were made to the geek layer. I also drew some new eyes with the drawing tools and placed them over the old eye. I left this scene and all the others after this on for 15 frames in order to give people time read the text and note the difference in the geek.This scene starts at frame 113, where I placed a keyframe. I deleted the spots from the geeks face and entered new text into the text box.Another keyframe was placed at frame 128 in the geek layer. I drew another mouth using the drawing tools and placed it over the old one. I also edited the text in the text box.I placed another keyframe at frame 143 in the geek layer. I deleted the excess hair from the nose and ears with the aid of the eraser tool from the drawing tools. I then re-drew the hair using the paintbrush tool. Again, I edited the text.7This keyframe was added at frame 158 in the geek layer. I used the drawing tools to change the shape of the face and changed the text.A keyframe was inserted at frame at 173, and again drawing tools were used to change the shape of the body.This keyframe is at frame 188 and I used the fill tool to change the colours of the clothes.This is the last scene and the keyframe was inserted at frame 203 and I used the text tool to edit the text. I also created a button using the drawing tool to draw it. I then added an action to the button, which is ‘go to and play’ frame 1, which is the beginning of the film. I also added some sound to this frame, which says “hey baby!”, by changing the frame properties.8This concludes my film. The final step is to convert the Flash file into a movie so that is can be viewed in Flash players (File ! Export Movie ! specify file name and Save).6. ConclusionsI found Macromedia Flash a very powerful tool. It allowed me to draw pictures and make simple animations quite easily. I found Flash relatively easy to use when drawing basic pictures and animations, but it started to get very complicated when I attempted to produce more advanced animations. In my film, where the rays bombard the geek, I tried to animate the geek so that it looked like he was getting electrocuted. Unfortunately I was unable to do this. When I animated the geek Flash automatically turned the geek into a symbol, which meant that I was unable to change the appearance of the geek after this. This meant that I could not finish my film as the last part of the film is concerned with editing the appearance of the geek. I therefore decided that it would be more beneficial to not have the animated geek, but to have the appearance of the geek change. Flash has a large variety of tools, but there are far too many to learn. It would take a tremendous amount of time to fully learn all the tools and functions available. Also, as there are lots of things that Flash can do, it is hard to know exactly what can be done, as lots of time would be required to learn everything. It can also get very confusing knowing what does what. There are a number of tutorials that are available in the Flash software, which cover: • Basic drawing • Concepts • Buttons • Simple animation • Streaming audio These tutorials are extremely useful as you can learn enough to make a simple film and are very easy to follow. There are step-by-step instructions on how to make objects and lots of screen dumps so you can check if you are doing the right thing. Flash also has a good Help, where you can search on keywords. The concept of layers in Flash is extremely useful as it helps to organise objects. You can also colour code the layers, which helps to show which objects belong to which layer, especially when there are a lot of objects. It is also possible to lock layers, which is useful when you do not want to accidentally change objects, Making simple animations is quite straight forward, especially since there is a whole tutorial on it. But it is a lot harder to make complex animations, as there is no extra help. I found Flash quite easy to use, but to fully master it would take a lot of time and energy. It is very good for making multimedia content, as it allows you to incorporate graphics with animation and sound without any programming knowledge. It can annoying sometimes as it can quite awkward to draw objects as you want and it could benefit from more advanced drawing tools. Also, more help is needed on how to produce animations.97. References1. /alertbox/9512.html (last accessed 13/12/02) 2. http://www/iboost/com/build/design/articles/pageview/603.htm (last accessed 13/12/02) 3. /acrlnec/sigs/itig/tc_july_aug2000.htm (last accessed 13/12/02) 4. /software/flash/productinfo/usability/tips/ (last accessed 13/12/02) 5. /macromedia/events/john_gay/page04.html# (last accessed 13/12/02) 6. /approach/ (last accessed 13/12/02) 7. Allaire.J, Macromedia Flash MX – A next - generation rich client 8. /archives/2000/10/desirevu2/ (last accessed 13/12/02) 9. /TR/smil20/ (last accessed 13/12/02) 10. /Graphics/SVG/Overview.htm8 (last accessed 13/12/02)10。
安许茨系列陀螺罗经资料
传向系统
1. 作用：将主罗经的航向准确地传送到分 罗经、航向记录器等复示航向的仪器
2. 组成：同步发送机、同步接收机〔分罗 经或航向记录器〕
3. 工作原理：属沟通同步式传向系统，基 于自整角机的工作原理
雷达
测向仪
随动系统与传向系统工作框图:
随动系统
传向系统
航 向 记 录 器
航向记录器
作用： ①检查操舵状况 ②从启动过程中推断罗经的工作是否正常，是否稳定指北。 ③停靠时，用于测定罗经的技术参数TD、T0、f，以此来推断罗经性能的好 坏。
附件:安许茨IV型罗经技术指标
1．直航精度： ≤1°
2．适用纬度： 0 ～ 750〔南，北纬〕
3．适用航速： 0 ～ 45 Kn
4．环境温度：10 0C ～ 45 0C
5．稳定时间： 约4h
6．船舶电源：三相沟通380/440V，50/60Hz
7．电压：陀螺球及随动系统 110V333Hz〔±3%〕
保养工程
1．更换支承液体与更换陀螺球
2．支承液体的配制与陀螺球高度的调 整。
3．三相电流的检查与调整
4．随动系统灵敏度、随动速度及振荡 次数的检查
更换支承液体与更换陀螺球
1．更换支承液体 一般支承液体应每年更换一次。步骤如 下： 〔1〕关闭罗经约经1.5h，待陀螺马达完 全停转后，方可对主罗经进展拆卸；
3．罗经工作稳定后，且罗经桌呈水平、 液温正常的前提下，读取球高应为 2±1mm。
4．读取罗经航向示度时，必需查速度误 差表进展误差校正。
5．校对分罗经航向是否与主罗经的全都。
6．检查支承液体的液面高度是否满足要 求〔40－50 mm〕。
定期检查工程
1．检查三相电流是否符合要求值。 2．检查液温是否在52°±3℃。 3．检查球高是否在2±1mm。 4．每二小时校对一次陀螺罗经航向与磁罗经 的航向〔检查罗经好坏〕。 5．校对分罗经航向是否与主罗经的全都。 6．检查支承液体的量是否足够。
电罗经安修斯STD-22技术资料
安修斯电罗经STD22及标准配备分罗经技术资料1、（1）Standard 22 Compact Gyro Compass STD22电罗经1SET1)Performance性能标准Type型号：STD-22，产地：ANSCHUETZ德国Power supply电源：DC24VAutomatic Speed Error Correction 自动速度误差校正Automatic Dynamical Error Correction 自动动态误差校正Type Approval (IMO) Including High Speed (70 knots) IMO认可,包括适用达70节高速船认可信号输出:2 x NMEA or Course Bus NMEA或安修司Course总线1 x Course Bus 安修司Course总线4 x Status (Potential Free Contact) 状态输出(无源触点信号)Signal Input From:信号输入:1 x NMEA 0183 From GPS (GLL/GGA) NMEA 0183从GPS1 x log: 200 or 400 p/NM or NMEA 0183 and Direction 200或400脉冲/海里或NMEA 0183 148-4502）Comprising设备配置1 Master Compasses Standard 22 主罗经1 Gyrosphere 罗经球1 Supporting Liquid and Distilled Water 支撑液和蒸馏水1 on Board Spare Parts 船用备件1 NMEA/Course Bus Booster 1 input/8 outputs Serial booster NMEA/course bus数字信号分配器，1进8出1 AC-DC Converter (115/230 V AC, 24 V DC, 240 W)电源单元（2）ANSCHUETZ Repeater Compass 安修司航向分罗经 133-560 1SET for flush mounting* - IP 23 嵌入安装–IP23. self synchronizing 自同步. large compass card (150 mm) 150mm的罗经指示盘. analogue and digital display 模拟及数字显示. heading source indication 航向信号指示. ANSCHÜTZ course-bus system or NMEA 0183 安修司Course-bus信号或NMEA1083信号. dimmer button and anti-glare screen 调光按钮及防晕罩（3）Bearing Repeater Compass 方位分罗经 133-407 2SETS Standard Type - IP 56 标准形式IP-56Self Synchronizing 自同步• ANSCHUETZ Course Bus-System or NMEA 0183 Input接入安修司Course总线系统或NMEA 0183• Large 360 Degree Compass Card 190 mm直径为190毫米的360度读数盘• Incl. Dimmer包括调光（4）Pelorus Stand方位分罗经立式支架 2SETS For bearing repeater 133-407 incl. junction box方位分罗经立式支架，带防水接线盒（5）Bearing Sight CP 190方位圈 CP 190 1SET The bearing sight comes in a protective case for safe storage装在箱子里（6）Repeater分罗经 133-558+ 1SET Repeater Compass 360° (wall mounting)/壁挂式安装Self synchronizing/自同步150 mm compass card/150mm罗盘Dimmer/调光（7）ANSCHUETZ Steering Control System/操舵系统 Bst.: 2140 1SET Dual FU with handwheel for dual FU-steering control with max 6 switch positions including CAN bus follow-up amplifier and feedback unit双随动，手轮同步控制6个位置选择开关，总线连接Flush Mounting* 嵌入安装Comprising: 包括：1 Dual FU Steering Insert随动手轮1 Change Over Switch (2 axes, 2x10 sw. poles, 6 sw. positions)六位模式选择开关2 Steering Interface AS操舵接口板2 Follow-Up Amplifier AS随动放大板2 Rudder Feedback Unit Bus AS反馈单元（总线）2 Lever Drive for Feedback Unit (450-700mm)反馈连杆3 Dual NFU Tiller 12 Contacts非随动手柄（8）Digital Autopilot Pilotstar D 安修司数字自动舵Pilotstar D 1SETFlush Mounting* 嵌入安装For Connection to Gyro Compass (ANSCHUETZ Course-Bus or 6 Step/Degree.) and For Control of Steering Gears with ON/OFF Solenoid Valves (MAX. 45 W) or For Control of Steering Gears with Proportional Signal Output (2 x ±10V) and Direct Input for upto 3 Tillers连接电罗经（安修司Course总线或6步/度），控制舵机的开关电磁阀（最大45W），或控制舵机的对应信号输出(2 x ±10V) 以及3个舵柄的直接输入Comprising:包括：1 Operator Unit (IP 44) Incl. 2.5 m Cable* 操作单元(IP 44)，包括2.5m电缆1 Connection Unit with Amplifier (IP 22) 带放大器的连接单元(IP 22)1 Set on Board Spare Parts 船用备件。
不同型号罗经对ADCP流量测验精度影响浅析
不同型号罗经对ADCP流量测验精度影响浅析作者：张馨月程肖雪来源：《科技视界》2014年第17期【摘要】声学多普勒流速剖面仪（ADCP）是当前水文行业应用较广的新型流量测验仪器，该技术具有测流历时短、采集数据量大、精度高等优点。
本文通过对外接罗经在该仪器中的作用及误差分析，探讨如何提高ADCP测流精度。
【关键词】ADCP流量测验；罗经；误差分析；精度0 引言ADCP是英文ACOUSTIC DOPPLER CURRENT PROFILES的缩写，中文译为声学多普勒流速剖面仪。
经过多年的比测分析，该仪器逐步取代老式常规法的旋浆式流速仪，成为内陆河流流量测验主要手段和方法。
但是在实际投产应用过程中，有两个问题制约着该仪器的测验精度：（1）当测验断面含沙量较大或存在“河底走沙”情况时，会造成流速测量错误。
流量系统偏小；（2）ADCP仪器内置磁罗经易受铁磁体干扰，导致流向测量错误，从而影响流量精度。
为解决上述问题，经过大量的比测实验，已经摸索出通过外接高精度GPS来测量流速可以解决高含沙量和“河底走沙”问题，通过外接罗经可以解决ADCP内置罗经受铁磁体干扰失效问题。
本文主要比较几种不同类型罗经之间的区别和实际应用情况，以及对流量测验精度的影响。
1 罗经在ADCP测流系统中的作用罗经在ADCP测流系统中的作用是将系统ADCP的仪器坐标转换成大地坐标，通俗的说就是在ADCP仪器安装时，3号探头方向必须与测船中轴线方向保持一致，而3号探头的方向和大地正北方向的关系由罗经决定，进而将3号探头方向确定下的仪器坐标测量值通过罗经而转换成大地坐标。
铁质船体对ADCP内置罗经存在比较大的磁场干扰影响，使得ADCP内置罗盘产生“磁偏角”，导致罗盘和倾斜计提供错误（或者偏离）的方向和倾斜数据，因此，在受到磁场干扰的情况下，ADCP测得的流速是有误差的。
当ADCP换能器声波发射以后，从不同深度返回的散射回波时间是不同的，换能器检测不同时间上的频移，即可得到不同层中散射体的相对速度，也就是水流相对ADCP（或船）的速度，该速度是建立在仪器坐标系统之上，需将转换到大地坐标。
罗先觉电路PPT讲解
开路
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实际电阻器
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1.6 电压源和电流源
1.理想电压源
定义 其两端电压总能保持定值或一定 的时间函数，其值与流过它的电 流 i 无关的元件叫理想电压源。 i 电路符号
求图示电路中各 方框所代表的元件吸 收或产生的功率。
+
U3 3 －
I2
已知： U1=1V, U2= -3V，U3=8V, U4= -4V, U5=7V, U6= -3V，I1=2A, I2=1A,，I3= -1A
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+
I1
+ 2 U2 － +
U1 － + 1 － U4 4
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P6 U 6 I 3 (3) (1) 3W（吸收）
对一完整的电路，满足：发出的功率＝吸收的功率
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1.4 电路元件
1. 电路元件
是电路中最基本的组成单元。 5种基本的理想电路元件： 电阻元件：表示消耗电能的元件 电感元件：表示产生磁场，储存磁场能量的元件 电容元件：表示产生电场，储存电场能量的元件 电压源和电流源：表示将其它形式的能量转变成 电能的元件。
例 电感线圈的电路模型
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1.2 电流和电压的参考方向
电路中的主要物理量有电压、电流、电荷、磁 链、能量、电功率等。在线性电路分析中人们主要 关心的物理量是电流、电压和功率。
航海科普——电罗经磁罗经
我们童年有不少就地取材、自制的玩具。
比起现在儿童到玩具店购买的现代高级玩具来讲，简直不可同日耳语。
一个字“土”囊刮全部，土的不堪入目。
可是，我们玩的浑身上下沾满了泥土。
玩的有姿有色、玩的疯狂、玩的胆颤心跳、玩的热火朝天、玩的汗流浃背、玩的废寝忘食，倒也成全了家里缺衣少粮。
在玩中我们忘记了长大，忘记了营养不良，忘记了烦恼，忘记了那个年代。
陀螺罗经在现代远洋船舶上东南西北的方向就是由老祖宗“四大发明”之一的指南针（也称为指北针、司南）指示航向。
指南针在航海导航仪器中的正规名字叫磁罗经，它是依靠地球的两极（即北极和南极）固有磁性的特性“同性相斥，异性相吸”的自然现象制成了带有磁性的指针，放在刻度盘上标示出东南西北来。
整个罗盘分为360度，正北为000度；正东为090度；正南为180度；正西为270度，转一圈360度，又返回到了000度。
方位图然而，由于地球的磁极并不是指向正北或正南，就存在磁差。
因此航海上为了准确抵达目的港，必须进行每一个地区和海区的磁差修正，这个修正值科学家已经标绘在航用海图的罗经花上了，它每年都有比较恒定的变化。
磁罗经还受到船舶材质的影响，因为现代船舶都是钢铁制成的，还有一些货物也是与钢铁制品有关系而对磁罗经产生影响，所以磁罗经还存在每一个航次都不同的自差。
为了消除这个自差，船舶驾驶员就需要调整在航行过程的自差值，必须经常白天根据太阳低高度方位、夜间根据北极星正北方位和其他天体的方位、近洋或沿海航行根据陆标方位等参照物进行修正磁罗经自差。
因此如果要得到准确的磁罗经航向，就得将磁罗经的磁差和自差合成修正才不会发生偏航。
由于磁罗经存在这些固有的固定误差和偶然误差给航海带来了不便，科学家开始寻求更先进的航向指示仪器。
在经过漫长的探索和观察，科学家们发现孩子们玩的陀螺在高速旋转时具有非常稳定的指向特性。
于是，他们研发出了结构、线路很复杂的电罗经。
这种电罗经内部有一个陀螺球，在供电的情况以每分钟12000转以上的高转速运转，保持了它的稳定指向，再经过地理位置的自动修正系统，克服了磁罗经固有的缺陷，它可以在世界上的任何地点都保持稳定的指北特性，似乎它的指针一直和北极星保持一致。
Luo et al[1].2008-3P
![Luo et al[1].2008-3P](https://img.taocdn.com/s3/m/e808b9c10c22590102029d0f.png)
Size variation of conodont elements of the Hindeodus –Isarcicella clade during the Permian –Triassic transition in South China and its implication for mass extinctionGenming Luo a ,Xulong Lai a ,⁎,G.R.Shi b ,Haishui Jiang a ,Hongfu Yin a ,Shucheng Xie c ,Jinnan Tong c ,Kexin Zhang a ,Weihong He c ,Paul B.Wignall daFaculty of Earth Science,China University of Geosciences,Wuhan 430074,PR ChinabSchool of Life and Environmental Sciences,Deakin University,221Burwood Hwy,Burwood VIC 3125,Australia cKey Laboratory of Geobiology and Environmental Geology,China University of Geosciences,Wuhan 430074,PR China dSchool of Earth and Environment,University of Leeds,Leeds.LS29JT,United KingdomA B S T R A C TA R T I C L E I N F O Article history:Received 17August 2007Received in revised form 1April 2008Accepted 3April 2008Keywords:Multi-episode mass extinction ConodontHindeodus -Isarcicella Size reductionPermian –Triassic transition South ChinaBased on the analysis of thousands of conodont specimens from the Permian –Triassic (P –T)transition at Meishan (the GSSP of P –T Boundary)and Shangsi sections in South China,this study investigates the size variation of Hindeodus and Isarcicella P1elements during the mass extinction interval.The results demonstrate that Hin-deodus –Isarcicella underwent 4episodes of distinct size reduction during the P –T transition at the Meishan Section and 2episodes of size reduction in the earliest Triassic at Shangsi.The size reductions at Meishan took place at the junctions of beds 24d/24e,25/26,27b/27c and 28/29,and at the junctions of beds 28/29c and 30d/31a at Shangsi.The two earliest Triassic size reduction episodes were correlative between the two sections.These changes coincide with some important geological events such as eustatic sea-level changes,anoxic events,carbon isotope oscillations,miniaturization of brachiopods and microbial changes.Through detailed investigation of the palaeoenvironment and the palaeoecology of Hindeodus –Isarcicella ,the authors propose that the main causes of the size reduction was a sharp decline of food availability because of the mass extinction and the anoxic event during the P/T transition.The pattern of size reduction supports suggestions that the end-Permian mass extinction was multi-episodal,consisting of 3extinction events rather than a single catastrophic event.©2008Elsevier B.V.All rights reserved.1.IntroductionThe end-Permian biotic crisis was the largest mass extinction in the fossil record.It eliminated over 90%of species in the oceans (Stanley and Yang,1994;Bambach et al.,2004)and about 70%of vertebrate families on land (Benton,1988;King,1991;Maxwell,1992).The cause or causes and duration as well as the nature of the extinction remain uncertain and actively debated (Wu and Liu,1991;Wignall and Hallam,1993;Isozaki,1997;Kozur,1998;Yin and Tong,1998;Jin et al.,2000;Yin et al.,2001;Wang and Cao,2004;Fang,2004a,b;Grice et al.,2005;Racki and Wignall,2005;Yin et al.,2007a ).The Global Stratotype Section and Point (GSSP)of the Permian –Triassic Boundary at Meishan in Zhejiang Province,China has served as a focal point in this global debate,as it has provided much critical stratigraphical and palaeontological data.As a result,the section has received intensive multidisciplinary studies by various research groups,including lithostratigraphy,biostratigraphy,sedimentology,sequence stratigraphy,isotope geochemistry,eventostratigraphy,and magnetostratigraphy (Yin et al.,2001and references therein).There are several opinions about the causes and patterns of the P –T mass extinction (Isozaki,1997;Kozur,1998;Wang and Cao,2004;Fang,2004a,b;Grice et al.,2005;Racki and Wignall,2005).Some authors have proposed a single-episode catastrophic mass extinction (Jin et al.,2000;Kaiho et al.,2006),while others have argued for a multi-episode mass extinction (Wu and Liu,1991;Wignall and Hallam,1993;Yin and Tong,1998;Fang,2004a,b;Xie et al.,2005;Shen et al.,2006;Yin et al.,2007a ).In this paper,we attempt to test these various scenarios by using the size variation data of a group of conodont species from a single clade from several continuous Permian –Triassic boundary sections in South China.The fundamental question addressed in the study is to see if the sizes of conodont species varied across the PTB and,if so,whether or not the timing of the signi ficant size changes actually corresponded to any of the proposed PTB extinction intervals.A related question,also investi-gated as an integral part of this study,is to elucidate the possible cause (s)for the size change of the conodont species across the PTB.There is now a considerable literature relating size variation in lineages through time to biotic crises caused by environmental changes in earth history.Initially,Urbanek (1993)coined the term “Lilliput effect ”for an observed size reduction of Silurian graptolites during a biotic crisis.Subsequently,other researchers have reported similar size decreases during times of extinction;for example,the sizePalaeogeography,Palaeoclimatology,Palaeoecology 264(2008)176–187⁎Corresponding author.Faculty of Earth Sciences,China University of Geosciences,Wuhan,Hubei 430074,PR China.Tel.:+862767883139;fax:+862787515956.E-mail address:xllai@ (X.Lai).0031-0182/$–see front matter ©2008Elsevier B.V.All rights reserved.doi:10.1016/j.palaeo.2008.04.015Contents lists available at ScienceDirectPalaeogeography,Palaeoclimatology,Palaeoecologyj o u r n a l h o me p a g e :w w w.e l sev i e r.c o m /l oc a t e /pa l a e oof late Devonian conodonts (Girard and Renaud,1996),heart urchins across the Cretaceous/Tertiary boundary (Jeffery,2001),and various organisms around the Permian/Triassic boundary (Twitchett,2001;He et al.,2005;Twitchett,2005a,b;Luo et al.,2006;Twitchett,2006;He et al.,2007;Twitchett,2007).It is widely held that there was no obvious change in conodont fortunes during the end-Permian mass extinction,because many conodont lineages clearly survived through the PTB (e.g.Clark et al.,1986;Jiang et al.,2007).However,the survival of lineages tends to overlook the potential ecological information that can come from the study of large conodont samples.Furthermore,unlike most other organisms,most Late Permian conodont species or their lineages persisted through into the Lower Triassic.Therefore,these conodonts can serve as the best material for the study of the size variation during the P –T transitional period.Luo et al.(2006)reported a size reduction in P1elements of the conodont genus Neogondolella at the bed 24d/24e junction (Upper Permian)at Meishan.However,the limited Neogondolella specimens from the Lower Triassic did not allow us to perform a full-scale size variation study throughout the Permian –Triassic transition.To overcome this shortfall,in this paper wehaveFig.1.A:Location map of study area in South China;Meishan Section (B)and Shangsi Section (C).(after Wingnall et al.,1995and Jiang et al.,2007).Table 1The total number,mean size,standard deviation,percentage of specimens larger than 0.5mm and 95%con fidence interval of the mean for the P1element of Hindeodus –Isarcicella from the P/T transition at the Meishan Section,Changxing,Zhejiang Province Bed24a 24b 24c 24d 24e 252627a 27b 27c 27d 2829Number 793957717289413314127017147Mean (mm)0.4580.4590.4430.5340.4360.5330.3920.4550.5030.4210.4670.5800.459Standard deviation 0.1320.1430.0790.0960.1000.0060.0430.0980.1080.1030.1580.1500.108Percentage (N 0.5mm)29.1133.3320.0076.6225.5310027.6647.3718.4434.4467.8438.3095%con fidence interval of the mean0.49130.49890.70020.56100.49510.58380.40480.47250.51820.43720.48710.60080.49260.42440.40260.18310.51440.35950.48220.36190.42980.48110.40170.44720.55360.4264177G.Luo et al./Palaeogeography,Palaeoclimatology,Palaeoecology 264(2008)176–187chosen hindeodid conodonts because as a lineage they survived across the P–T boundary.The recovery and size measurement of abundant conodont specimens is time-consuming,and this kind of study has only previously been undertaken for the P–T transition(Luo et al., 2006).The present paper examines the size variations,in large samples,of conodonts from the Hindeodus–Isarcicella clade duringtheFig.2.Size distribution histogram of P1elements of Hindeodus–Isarcicella from each bed in ascending order(24a to29except for bed25)through the P/T transition at the Meishan Section A.Thefigures above each histogram are the total number of specimens in each size range.178G.Luo et al./Palaeogeography,Palaeoclimatology,Palaeoecology264(2008)176–187end Permian to earliest Triassic interval,with the aim of improving our understanding of the mass extinction patterns and of biotic recovery.2.Material and methodThirteen successive bulk samples ranging from bed24to bed29 (the PTB is sited at the bottom of bed27c)were collected from Section A at Meishan,Changxing,Zhejiang province(Fig.1).The sample from bed24was divided into5sub-beds(beds24a–e).Bed27was also evenly separated into4sub-beds(beds27a–d).Each of these13 samples weighed20kg.The clay samples collected from beds25and 28were processed directly by water.The other samples were crushed into1cm3size fragments and treated with dilute acetic acid(10%)to dissolve the samples.A 2.80–2.81g/ml gravity liquid made of bromoform(2.89g/ml)and acetone(0.79g/ml)was used in the conodont separation for all the samples.The conodonts were picked one by one under the binocular stereoscope.All the Meishan samples have been entirely processed over20months.The samples from the Shangsi Section have not been completely processed but in the earliest Triassic there are Hindeodus–Isarcicella elements for this work.Over20,000specimens were obtained from this processing.Among these,more than14,000were P1elements of Neogondolella,Hindeodus and Isarcicella,which are important elements during the P/T transition.A binocular stereoscope and micrometer were used to measure the length between the anterior and posterior ends of each well-preserved Hindeodus–Isarcicella P1element.First,the complete elements with both anterior and posterior parts were measured under the binocular stereoscope with the micrometer in the ocular.Secondly,each measured element was arrayed according to its size recorded in the notebook. Thirdly,the size of some randomly-chosen elements was measured and compared to the measurements obtained from thefirst step and found to be nearly the same.Finally,different personnel were employed to measure some of the randomly chosen elements(about30–40elements of each bed)and compared their measurements with those of thefirst person,and again both results were found to be nearly the same.The mean size,distribution histogram,standard deviation and95% confidence interval of the mean size were used to analyse the size distribution and variation of the conodonts.The mean size(X),which reflects the condition of a community,is based on the following equation:X¼1=N4X Ni¼1liwhere X is the mean size,N is the number measured in each bed and li is the length of each element.The95%confidence interval,reflecting whether the size reduction is credible on95%confidence,is based on the following equation:Y¼t a=2SffiffiffiffiNpwhere Y is thefluctuating range,t a=2is the t-test value of1−αconfidence,S is the standard deviation and N is the number measured from each bed.So,the confidence interval is(X−Y,X+Y),where X is the mean size,X−Y is the lower line,while X+Y is the upper line.3.Taxonomy and evolution of Hindeodus–IsarcicellaBoth hindeodid and isarcicellid P1elements are scaphate,with a robust cusp at the anterior and numbers of smaller denticles following the cusp.The hindeodid P1elements are symmetrical or slightly asymmetric,whilst the isarcicellid P1elements are extremely asymmetric.The cavity of hindeodid shows slight swelling but no thickening,whilst that of isarcicellids is both swollen and thickened. Some of the isarcicellid P1elements have a denticle or series of denticles on one side or both sides of the cavity surface.Interpreta-tions of the evolution of the hindeodid–isarcicellid lineage are controversial(Kozur,1996;Ding et al.,1997;Lai,1997;Wang and Wang,1997).Ding et al.(1997)thought that Hindeodus latidentatus–H. parvus–Isarcicella turgida–I.isarcica formed an anagenetic lineage. However,Wang and Wang(1997)replaced I.turgida with I.staeschei in the evolutionary sequence of(Ding et al.,1997).Nevertheless, almost all authors have accepted the idea of an evolutionary sequence from hindeodid to isarcicellid.Nicoll et al.(2002)proposed that the growth pattern of hindeodids occurred by the addition of denticles at the posterior.The length between the anterior and posterior is therefore an important size parameter for Hindeodus–Isarcicella.During the past two decades,the P–T conodonts at the Meishan section have received intensive studies(Lai et al.,1995;Zhang et al., 1995;Ding et al.,1997;Wang and Wang,1997;Mei et al.,1998).Based on large conodont samples,our group has established parallel gondolellid and hindeodid zones at this section(Jiang et al.,2007), and the hindeodid zones in ascending order are tidentatus zone, H.praeparvus zone,H.changxingensis zone,H.parvus zone,Isarcicella staeschei zone and I.isarcica zone from beds24a to29.According to the latest radiometric dates,the absolute age of bed28at the Meishan Section(GSSP)is250.7±0.3Ma,and that of bed25(white clay)is 251.4Ma(Bowring et al.,1998).Mundil et al.(2004)rectified their earlier data(Mundil et al.,2001),and suggested that the duration of the mass extinction was shorter.In any case,the duration from bed25 to28is about0.7million years.This0.7myr interval corresponds to4 hindeodid conodont zones and hence indicates that the evolutionary rates were high for the conodonts.4.Size variation in the Hindeodus–Isarcicella clade4.1.Data from the Meishan sectionThe number(all the complete elements from each bed),mean size and standard deviation of P1elements of Hindeodus–Isarcicella for each bed are shown in Table1,together with the95%confidence interval of the mean and the percentage of Hindeodus–Isarcicella P1 elements larger than0.5mm.The size distribution within each bed is shown in Fig.2.The mean size of all the individuals within a community which can more precisely reflect the living environment of this community is shown in Fig.3,of which the shadow interval shows the95%confidence interval of the mean.The dominant peak for bed24a is0.4–0.5mm,with element length showing a normal distribution(Fig.2).The dominant peak for bed24b is0.3–0.4mm,but with a marked right-skewed distribution (skeweness=0.3112).The dominant peak for bed24c is also0.4–0.5mm,with a normal distribution,although with fewerelements.Fig.3.Variation of the mean size of P1elements of Hindeodus–Isarcicella from the end Permian(bed24a)to early Triassic(bed29)at the Meishan Section.The black area is the 95%confidence interval of the mean size,and the central white circle and line show variation of the mean size.179G.Luo et al./Palaeogeography,Palaeoclimatology,Palaeoecology264(2008)176–187The dominant peak for bed 24d is 0.5–0.6mm,and it also appears to have a normal distribution.The dominant peak for bed 24e is 0.4–0.5mm,with a marked left-skewed trend.Both the two elements of bed 25are larger than 0.5mm,while the elements of bed 26are 0.3–0.5mm,with no element larger than 0.5mm.The dominant peaks for bed 27a and 27b are within 0.4–0.5mm,and their distribution approaches a normal distribution.The dominant peaks for bed 27c and 27d are 0.3–0.4mm,with slight right skew.The dominant peak for bed 28is 0.5–0.7mm,while that for bed 29is 0.4–0.5mm.Fig.3shows the size variation of conodont Hindeodus-Isarcicella P1element from the end Permian (bed 24a)to earliest Triassic (bed 29).The black area stands for the 95%con fidence interval of the mean,and the central white points and line of the area show the variation of mean size of specimens in each bed.As the graph (Fig.3)shows,during the transitions between beds 24e/24d,26/25,27c/27b and 29/28,the characters (mean size,dominant peak,percentage)of size variation exhibit distinct changes.The dominant peak and the mean size for bed 24d are 0.5–0.6mm and 0.534mm respectively,and the percentage with a size larger than 0.5mm is 76.62%,while these characters for bed 24e are 0.4–0.5mm,0.436mm and 25.53%,respectively.The 95%con fidence interval of the mean size shows that the upper line of bed 24e (0.4951)is smaller than the lower line of bed 24d (0.5144),so the size reduction is credible at a 95%con fidence level.The t -test for means shows that the size reduction was distinct (p =0.000).There are only two Hindeodus –Isarcicella P1elements in bed 25,both of which are larger than 0.5mm,with a mean size of 0.533mm,while in bed 26all the elements are less than 0.5mm,and the mean size is only 0.392mm.The t -test for means (p =0.002)indicates the size variation was signi ficant.Also,the size reduction in bed 26is credible as shown by the 95%con fidence interval of the mean shown in Table 1.In beds 27and 28,Hindeodus –Isarcicella replaced Neogondolella as the dominant genera.There are abundant Hindeo-dus –Isarcicella P1elements in these beds.Jiang et al.(2007)identi fied three assemblages from the end Permian (bed 24a)to the earliest Triassic (bed 29)by comparing the ratio of Hindeodus –Isarcicella P1elements to the Neogondolella P1elements,and beds 27and 28belong to their second assemblage.In bed 27b,the dominant peak and themean size are 0.4–0.5mm and 0.503mm,and the percentage with a size larger than 0.5mm is 47.37%,while in bed 27c,the dominate peak and the mean size are 0.3–0.4mm and 0.421mm respectively,and the percentage of size larger than 0.5mm is 18.44%.The upper line (0.4372)of the 95%con fidence interval of the mean at bed 27c is smaller than that of the lower line (0.4811)at bed 27b.The t -test for means (p =0.000)indicated that this reduction of size was undoubted.In bed 27d,the dominant peak is 0.3–0.4mm,the same as bed 27c,but the mean size is 0.467mm,and the percentage with a size larger than 0.5mm is 34.44%.The mean size in bed 28,where the largest specimens in these beds are found,is 0.580mm,the dominant peak is 0.5–0.6mm,and the percentage with a size larger than 0.5mm is 67.84%.However,in bed 29,the dominant peak and mean size are 0.4–0.5mm and 0.459mm,respectively,and the percentage with a size larger than 0.5mm is 38.30%.At the transition between these two beds,all the parameters vary distinctly,and the upper line (0.4926)of the 95%con fidence interval for bed 29is much smaller than the lower line (0.5536)for bed 28.t -test for means shows no reason to believe that the size reduction was not signi ficant (p =0.000).It is interesting to note that the size of P1elements of Hindeodus –Isarcicella in beds 25and 28is comparatively very large,especially in bed 28(see above).Both of these are clay beds,and previous workers have thought that the extinction took place at these levels (Fang,2004a,b;Xie et al.,2005).In order to determine whether or not the size variation of Hindeo-dus –Isarcicella populations was affected by the presence of different species,we investigated the size variation of a single species,Hindeodus typicalis ,from beds 24a to 24e.This reveals fluctuations similar to those shown by the overall population of conodonts,with a peak size in Bed 24d and a marked reduction in Bed 24e (Fig.4).t -test for means shows that the size reduction during this transition was signi ficant (p =0.007).4.2.Data from the Shangsi sectionTable 2,Figs.5and 6show the size variation of P1elements of Hindeodus –Isarcicella and Hindeodus from the Shangsi Section,Sichuan Province.The first change was recognized in thetransitionFig.4.Variation of the mean size of P1elements of Hindeodus typicalis from the end Permian (bed 24a to bed 24e)at the Meishan Section.The black area is the 95%con fidence interval of the mean size,and the central white circle and line show variation of the mean size.Table 2The total number,mean size,standard deviation and 95%con fidence interval of the mean of specimens of the P1element of Hindeodus-Isarcicella of earliest Triassic age from the Shangsi Section,Guangyuan,Sichuan Province Bed28c 28d 29a 29b 29c 30(b +c)30d 31a 31b 3233Number 1111247732104411915Mean(mm)0.3550.4310.1940.3390.3130.3900.4020.3480.3640.3430.455Standard deviation0.05100.0660.0440.1050.0660.0780.1140.0620.13195%Con fidence interval of the mean0.39490.36300.35380.46810.42560.36310.40040.37350.52770.32720.30430.27310.31230.37830.33290.32770.31340.3829Fig.5.Variation of the mean size of P1elements of Hindeodus –Isarcicella from the earliest Triassic of the Shangsi Section,Sichuan Province.180G.Luo et al./Palaeogeography,Palaeoclimatology,Palaeoecology 264(2008)176–187between beds 29c and 28(combined beds 28c and 28d)in the Hin-deodus parvus zone (Lai et al.,1996).The upper line (0.3538)of the 95%con fidence interval of the mean size of bed 29c is larger than the lower line (0.3272)of bed 28,while the upper line of the 75%con fidence interval of the mean size of bed 29c (0.3321)is smaller than that of the lower line of bed 28(0.3381),and the t -test for means (p =0.021)also shows there is no reason to doubt this size reduction..The second size change was during the transition between bed 30d and 31a,in the I.isarcica zone.The upper line (0.3631)of the 95%con fidence interval of the mean size of specimens in bed 31a is smaller than the lower line (0.3783)for bed 30d.So,the size reduction of this episode is credible at a 95%con fidence level,and the t -test for means (p =0.001)also supports this phenomenon.As in the Meishan section,these data show that conodont size underwent two-episodes of reduction at the Shangsi section during the earliest Triassic.A comparison of the mean sizes of elements in these two sections shows that the mean size of hindeodid conodonts from the Shangsi Section is smaller than that of the Meishan Section.There is no reason to doubt that the difference in mean size is creditable as shown by a t -test of the means (p =0.000).This difference in means size between the two sections will be discussed below.5.DiscussionThe genera Hindeodus and Isarcicella survived the P –T mass extinction and then flourished in the earliest Triassic.Taxonomically,both genera present no obvious change after the major extinction events during the P –T transition.However,the Hindeodus –Isarcicella populations show several episodes of size reduction of P1elements in this interval.As shown in Fig.3–6,from the latest Permian to earliest Triassic the mean size of P1elements of Hindeodus –Isarcicella remained nearly the same except for the several times when they experienced obvious size reductions.If the size changes are evidence of biotic crisis (Girard and Renaud,1996;Schmidt et al.,2006;Twitchett,2007),it would indicate that there were several crises that affected the growth of the conodonts in the P/T transition period.Normally,it is dif ficult to distinguish juvenile hindeodids from small adult elements (Dr.Robert Nicoll,personal communication 2006).However,the texture and the thickness of the cavity are different in the juvenile and adults.The cavity of the juvenile is thin and translucent,whilst that of the adult is thick and ing this criterion,we interpret the size reductions of Hindeodus –Isarcicella elements in our study to be indicative of populations with a higher proportion of juveniles.The evolutionary rate of the hindeodid –isarcicellid clade through the PTB interval is very high,re flecting a rapidly changing environment.In this sense,these conodonts did respond to the P –T mass extinction.The temporal pattern of the conodont size variation is also coincident with someother important geological events such as an anoxic event,sea-level changes and carbon isotope oscillations (Fig.7).5.1.Palaeoecology of conodont Hindeodus –IsarcicellaThe palaeoecology of Hindeodus and Isarcicella is still controversial.There are two main views:one viewpoint considered Hindeodus –Isarcicella to be a near-shore,shallow water taxon (Clark,1974;Wardlaw and Collinson,1984;Tian,1993;Hirsch,1994;Baud,1996;Krystyn and Orchard,1996;Orchard,1996);the other supposed that Hindeodus –Isarcicella had a wide facies range and occurred both in shallow and deeper water environments (Behnkn,1975;Clark,1981;Zhang,1990;Kozur,1995,1996;Kozur,1998).Kozur (1995)also pointed out that Hindeodus shows no provincialism and straddles the P/T boundary and is therefore the most suitable genus for de fining the P/T boundary within a phylomorphogenetic line.Lai et al.(2001)and Lai and Zhang (1999),based on the evolution of Hindeodus –Isarcicella and Clarkina (Neogondolella ),and on palaeoen-vironmental interpretations of the Meishan D Section,concluded that Hindeodus was pelagic,found in sediments deposited at different depths,but living in the top layer of the ocean water.They also suggested that the replacement of Clarkina by Hindeodus was caused by the development of anoxic bottom waters during the Permian –Triassic transition and into the Early Triassic.If the upper water became anoxic (Grice et al.,2005;Huang et al.,2007),even Hindeo-dus –-Isarcicella would be affected.Nicoll et al.(2002)also noted that Hindeodus was present in a wide range of marine depositional environments,but they thought the replacement of Neogondolella by Hindeodus –Isarcicella was due to an increase of turbidity levels.If the turbidity of the water was one of the main factors affecting the size reduction of Neogondolella as proposed by Luo et al.(2006),it cannot have been the reason for the size reduction of the conodont Hindeo-dus –Isarcicella .On the basis of previous literature regarding the ecology of Hin-deodus –Isarcicella and the characters of these conodonts at the Meishan A section,the authors consider that Hindeodus –Isarcicella were pelagic conodonts,maybe dwelling in the photic-zone or somewhat deeper,thereby appearing as fossils in both shallow and deep water facies.The anoxic event may have impacted on the evolution of Hindeodus –Isarcicella,which suggested that perhaps implying photic zone anoxia (such as bed 27at the Meishan Section,Grice et al.,2005).There are also different opinions regarding the feeding mechan-isms of conodonts.Nicoll (1985,1987)thought that the conodont apparatus is the filtering array of a microphagous active suspension feeder,while others have interpreted it to be the grasping and food-processing structure of a macrophagous predator or scavenger (Briggs et al.,1983;Aldridge et al.,1987;Purnell,1993).In either case,the abrupt decline of food supplies could have driven the size reduction of the conodont populations,by creating high juvenile mortality.Based on the detailed study of the polygonal microsculpture of Neogondo-lella elements from bed 24e at Meishan (Jiang et al.,2008)indicates an high juvenile mortality at this bed.5.2.Palaeoenvironmental changes during the P/T transition5.2.1.Sea-level changesZhang et al.(1996)studied the sequence stratigraphy of the Meishan D section in detail and proposed that the top contact of bed 24d is a type II sequence boundary,that bed 24e was an upward shallowing parasequence,and that bed 27b to 29belongs to a transgressive systems i et al.(2001)and Lai and Zhang (1999)analyzed the sea-level change bed by bed from bed 24d to 29of the Meishan D section.They thought that the depth of deposition of bed 24d was about 20–60m,while that of bed 24e was about 30–40m.Bed 25,the “white clay bed ”,is composed of montmorillonite –illiteFig.6.Variation of the mean size of P1elements of Hindeodus from the earliest Triassic of the Shangsi Section,Sichuan Province.The black area is the 95%con fidence interval of the mean size,and the central white circle and line show variation of the mean size.181G.Luo et al./Palaeogeography,Palaeoclimatology,Palaeoecology 264(2008)176–187。