沪科版七年级上数学知识点总结

沪科版七年级上数学知识点总结1沪科版七年级上数学知识点总结(一)2014年10月第一章:有理数一、有理数的意义1-1正数和负数1、为什么初中数学要引入负数,答:正数和负数是在实际需要中产生的，我们可以用正数和负数来表示相反意义的量。2、在生产和生活中，相反意义的量主要有哪些,请列举:答:常见的有:(1)温度高于0度记作“+”，低于0度记作“-”。(2)高度高于海平面记作“+”，低于海平面记作“-”。(3)高于正常水位记作“+”，低于正常水位记作“-”。(4)超过标准重量记作“+”，低于标准重量记作“-”。(5)储蓄中存入为正，取installationpartmainincludingYunnanprovincetengchongCountyyongxingRiverprimaryandsecondaryhydropowerstationintheofpressurepipeandthepowerstationmetalstructure,whichlevelpowerstationpressurepipetotalabout562t(containingannex);IIlevelpowerstationpressurepipeabout733t(containingannex);levelpowerstationmetalstructureabout52.5t,containingdischargeGate2hole,rushedsandGate1hole,watermouthworkdoorandthestoppeddirtgatethe1hole,Qianpoolworkdoorandthestoppeddirtgatethe1hole;Secondarypowerstationmetaljunctionatabout19.5t,containingsandGate1hole,waterinletwatergateandtrashthe1hole;theirauxiliaryhoistequipmentandelectricalequipment.Concretepressurepipe,gate,trashandhoistingdeviceprojectpropertylist1-1~1-3.Table1-1themaincharacteristicsofthepenstocknumberitemparametertypecontrollersizeheadalongpipediameterpipelength11hydropowerstationpenstockopen-airexposedpipe,singlepipejointwatersupply1.3M931m0.8M8.3*2m22hydropowerstationpenstockopen-airexposedpipe,singlepipejointwatersupply1.4m1063.506m0.8M10*2mtable1-2hydropowerstationMaincharacteristicsofhydraulicmetalstructurenumberprojectnamegate,trashrack,door(gate...Pressurepipeandthemetalstructureinstallation9.1mainengineeringprofileyongxingriverlevelhydropowerstationpressurepipepipelineplaneShangalongRidgeislinelayout,andslopesurfacecontourclosevertical,GuanPowithoriginalgroundlinechanges,usedopentypeMingtube,singletubejointwaterway,competentdiameter1.3M,long931.00m,tworootnon-symmetric"Bu"typesupporttube,diameter0.8M,singlerootlong8.3M.Competenttoestablish12townPier,107buttress,telescopicsection11.SupportPierspacing8M,side-slidingbearing.Townpierfortheclosed-endstructureofgravity,basesurfaceintobedrock,pipeexcavationslope1:0.75withM5groutedrubbleslopeprotection,0.3M,bottomsidesewer,0.25mwide,deep0.3m,M5groutedrubblemasonry,setmaintenancestepladderontheleftside,1.0Mwide.Yongxinghe-?hydropowerstationpenstockpipesarrangedalongtheridgelineontheplane,andnearlyverticalslopecontourlines,GuanPochangeswiththeoriginalgroundline,withshallowbackfill-pipe,single-pipewatersupply,thecompetent1.4m,long1063.506m,twoasymmetric"y"pipe,diameter0.8M,single10m.Competenttoestablish12townPier,8expansionjoint.Townpierfortheclosed-endstructureofgravity,placedonsoftrockbasesurface,pipeconcreteC20onapedestal.Pipetrenchexcavationslope1:0.75,aftertheinstallationofsteeltube,compactedgravel出为负。(6)收入为正，支出为负。(7)盈余为正，亏损为负。(8)上升为正，下降为负。(9)进为正，出为负。(10)增加为正，减少为负。(11)向东为正，向西为负。„„3、你了解以下各种数的定义和范围吗,并举例。正数:大于0的数，叫做正数。分为正整数和正分数。(a,0)负数:小于0的数，叫做负数。分为负整数和负分数。(a,0)0:既不是正数，也不是负数。整数:正整数、0、负整数统称整数。分数:正分数、负分数统称分数。有理数:整数和分数统称有理数。有理数又分为正有理数、0、负有理数。非负数:通常又把0和正数称为非负数。(a?0)非正数:0和负数称为非正数。(a?0)4、有理数的两种分类方法是什么,installationpartmainincludingYunnanprovincetengchongCountyyongxingRiverprimaryandsecondaryhydropowerstationintheofpressurepipeandthepowerstationmetalstructure,whichlevelpowerstationpressurepipetotalabout562t(containingannex);IIlevelpowerstationpressurepipeabout733t(containingannex);levelpowerstationmetalstructureabout52.5t,containingdischargeGate2hole,rushedsandGate1hole,watermouthworkdoorandthestoppeddirtgatethe1hole,Qianpoolworkdoorandthestoppeddirtgatethe1hole;Secondarypowerstationmetaljunctionatabout19.5t,containingsandGate1hole,waterinletwatergateandtrashthe1hole;theirauxiliaryhoistequipmentandelectricalequipment.Concretepressurepipe,gate,trashandhoistingdeviceprojectpropertylist1-1~1-3.Table1-1themaincharacteristicsofthepenstocknumberitemparametertypecontrollersizeheadalongpipediameterpipelength11hydropowerstationpenstockopen-airexposedpipe,singlepipejointwatersupply1.3M931m0.8M8.3*2m22hydropowerstationpenstockopen-airexposedpipe,singlepipejointwatersupply1.4m1063.506m0.8M10*2mtable1-2hydropowerstationMaincharacteristicsofhydraulicmetalstructurenumberprojectnamegate,trashrack,door(gate...Pressurepipeandthemetalstructureinstallation9.1mainengineeringprofileyongxingriverlevelhydropowerstationpressurepipepipelineplaneShangalongRidgeislinelayout,andslopesurfacecontourclosevertical,GuanPowithoriginalgroundlinechanges,usedopentypeMingtube,singletubejointwaterway,competentdiameter1.3M,long931.00m,tworootnon-symmetric"Bu"typesupporttube,diameter0.8M,singlerootlong8.3M.Competenttoestablish12townPier,107buttress,telescopicsection11.SupportPierspacing8M,side-slidingbearing.Townpierfortheclosed-endstructureofgravity,basesurfaceintobedrock,pipeexcavationslope1:0.75withM5groutedrubbleslopeprotection,0.3M,bottomsidesewer,0.25mwide,deep0.3m,M5groutedrubblemasonry,setmaintenancestepladderontheleftside,1.0Mwide.Yongxinghe-?hydropowerstationpenstockpipesarrangedalongtheridgelineontheplane,andnearlyverticalslopecontourlines,GuanPochangeswiththeoriginalgroundline,withshallowbackfill-pipe,single-pipewatersupply,thecompetent1.4m,long1063.506m,twoasymmetric"y"pipe,diameter0.8M,single10m.Competenttoestablish12townPier,8expansionjoint.Townpierfortheclosed-endstructureofgravity,placedonsoftrockbasesurface,pipeconcreteC20onapedestal.Pipetrenchexcavationslope1:0.75,aftertheinstallationofsteeltube,compactedgravel1-2数轴、相反数和绝对值1-2-1数轴1、什么是数轴,你能画好一条数轴吗,答:规定了原点、正方向、和单位长度的直线。(所有的有理数都可以用数轴上的点表示。但数轴上的点并不是都表示有理数)。2、数轴的三要素是什么,数轴的三要素有什么规定,答:原点(任意、标0)、正方向(向右、箭头)和单位长度(合适)。3、观察数轴，回答下列问题。(1)有没有最大的正数,(没有)。有没有最小的正数,(没有)。有没有最小的正整数,(有，是1)。(2)有没有最小的负数,(没有)。有没有最大的负数,(没有)。有没有最大的负整数,(有，是-1)。installationpartmainincludingYunnanprovincetengchongCountyyongxingRiverprimaryandsecondaryhydropowerstationintheofpressurepipeandthepowerstationmetalstructure,whichlevelpowerstationpressurepipetotalabout562t(containingannex);IIlevelpowerstationpressurepipeabout733t(containingannex);levelpowerstationmetalstructureabout52.5t,containingdischargeGate2hole,rushedsandGate1hole,watermouthworkdoorandthestoppeddirtgatethe1hole,Qianpoolworkdoorandthestoppeddirtgatethe1hole;Secondarypowerstationmetaljunctionatabout19.5t,containingsandGate1hole,waterinletwatergateandtrashthe1hole;theirauxiliaryhoistequipmentandelectricalequipment.Concretepressurepipe,gate,trashandhoistingdeviceprojectpropertylist1-1~1-3.Table1-1themaincharacteristicsofthepenstocknumberitemparametertypecontrollersizeheadalongpipediameterpipelength11hydropowerstationpenstockopen-airexposedpipe,singlepipejointwatersupply1.3M931m0.8M8.3*2m22hydropowerstationpenstockopen-airexposedpipe,singlepipejointwatersupply1.4m1063.506m0.8M10*2mtable1-2hydropowerstationMaincharacteristicsofhydraulicmetalstructurenumberprojectnamegate,trashrack,door(gate...Pressurepipeandthemetalstructureinstallation9.1mainengineeringprofileyongxingriverlevelhydropowerstationpressurepipepipelineplaneShangalongRidgeislinelayout,andslopesurfacecontourclosevertical,GuanPowithoriginalgroundlinechanges,usedopentypeMingtube,singletubejointwaterway,competentdiameter1.3M,long931.00m,tworootnon-symmetric"Bu"typesupporttube,diameter0.8M,singlerootlong8.3M.Competenttoestablish12townPier,107buttress,telescopicsection11.SupportPierspacing8M,side-slidingbearing.Townpierfortheclosed-endstructureofgravity,basesurfaceintobedrock,pipeexcavationslope1:0.75withM5groutedrubbleslopeprotection,0.3M,bottomsidesewer,0.25mwide,deep0.3m,M5groutedrubblemasonry,setmaintenancestepladderontheleftside,1.0Mwide.Yongxinghe-?hydropowerstationpenstockpipesarrangedalongtheridgelineontheplane,andnearlyverticalslopecontourlines,GuanPochangeswiththeoriginalgroundline,withshallowbackfill-pipe,single-pipewatersupply,thecompetent1.4m,long1063.506m,twoasymmetric"y"pipe,diameter0.8M,single10m.Competenttoestablish12townPier,8expansionjoint.Townpierfortheclosed-endstructureofgravity,placedonsoftrockbasesurface,pipeconcreteC20onapedestal.Pipetrenchexcavationslope1:0.75,aftertheinstallationofsteeltube,compactedgravel1-2-2相反数1、什么是相反数,答:只有符号不同的两个数，我们说其中一个是另一个的相反数。这两个数叫做互为相反数。规定:0的相反数是0。数a的相反数是-a。2、相反数的几何意义是什么,答:在数轴上表示互为相反数的两个点，位于原点的两旁，且到原点的距离相等。3、什么数的相反数是它的本身,(是0)。什么数和它的相反数相等,(是0)。4、-a一定是负数吗,为什么,答:不一定，因为:当a是正数时，-a是负数;当a是负数时，-a是正数;当a是0时，-a也是0。installationpartmainincludingYunnanprovincetengchongCountyyongxingRiverprimaryandsecondaryhydropowerstationintheofpressurepipeandthepowerstationmetalstructure,whichlevelpowerstationpressurepipetotalabout562t(containingannex);IIlevelpowerstationpressurepipeabout733t(containingannex);levelpowerstationmetalstructureabout52.5t,containingdischargeGate2hole,rushedsandGate1hole,watermouthworkdoorandthestoppeddirtgatethe1hole,Qianpoolworkdoorandthestoppeddirtgatethe1hole;Secondarypowerstationmetaljunctionatabout19.5t,containingsandGate1hole,waterinletwatergateandtrashthe1hole;theirauxiliaryhoistequipmentandelectricalequipment.Concretepressurepipe,gate,trashandhoistingdeviceprojectpropertylist1-1~1-3.Table1-1themaincharacteristicsofthepenstocknumberitemparametertypecontrollersizeheadalongpipediameterpipelength11hydropowerstationpenstockopen-airexposedpipe,singlepipejointwatersupply1.3M931m0.8M8.3*2m22hydropowerstationpenstockopen-airexposedpipe,singlepipejointwatersupply1.4m1063.506m0.8M10*2mtable1-2hydropowerstationMaincharacteristicsofhydraulicmetalstructurenumberprojectnamegate,trashrack,door(gate...Pressurepipeandthemetalstructureinstallation9.1mainengineeringprofileyongxingriverlevelhydropowerstationpressurepipepipelineplaneShangalongRidgeislinelayout,andslopesurfacecontourclosevertical,GuanPowithoriginalgroundlinechanges,usedopentypeMingtube,singletubejointwaterway,competentdiameter1.3M,long931.00m,tworootnon-symmetric"Bu"typesupporttube,diameter0.8M,singlerootlong8.3M.Competenttoestablish12townPier,107buttress,telescopicsection11.SupportPierspacing8M,side-slidingbearing.Townpierfortheclosed-endstructureofgravity,basesurfaceintobedrock,pipeexcavationslope1:0.75withM5groutedrubbleslopeprotection,0.3M,bottomsidesewer,0.25mwide,deep0.3m,M5groutedrubblemasonry,setmaintenancestepladderontheleftside,1.0Mwide.Yongxinghe-?hydropowerstationpenstockpipesarrangedalongtheridgelineontheplane,andnearlyverticalslopecontourlines,GuanPochangeswiththeoriginalgroundline,withshallowbackfill-pipe,single-pipewatersupply,thecompetent1.4m,long1063.506m,twoasymmetric"y"pipe,diameter0.8M,single10m.Competenttoestablish12townPier,8expansionjoint.Townpierfortheclosed-endstructureofgravity,placedonsoftrockbasesurface,pipeconcreteC20onapedestal.Pipetrenchexcavationslope1:0.75,aftertheinstallationofsteeltube,compactedgravel5、3-5的相反数是什么,答:是-(3-5)或5-3。6、a-b的相反数是什么,答:是-(a-,)或,-,。7、a+b的相反数是什么,答:是-(a+b)。8、如果a、b是互为相反数，那么a+b=。1-2-3绝对值1、绝对值的定义是什么(即几何意义),答:一个数a的绝对值，就是数轴上表示数a的点与原点的距离，记作|a|。根据绝对值的概念，可知绝对值是非负数(|a|?0)。互为相反数的两个数的绝installationpartmainincludingYunnanprovincetengchongCountyyongxingRiverprimaryandsecondaryhydropowerstationintheofpressurepipeandthepowerstationmetalstructure,whichlevelpowerstationpressurepipetotalabout562t(containingannex);IIlevelpowerstationpressurepipeabout733t(containingannex);levelpowerstationmetalstructureabout52.5t,containingdischargeGate2hole,rushedsandGate1hole,watermouthworkdoorandthestoppeddirtgatethe1hole,Qianpoolworkdoorandthestoppeddirtgatethe1hole;Secondarypowerstationmetaljunctionatabout19.5t,containingsandGate1hole,waterinletwatergateandtrashthe1hole;theirauxiliaryhoistequipmentandelectricalequipment.Concretepressurepipe,gate,trashandhoistingdeviceprojectpropertylist1-1~1-3.Table1-1themaincharacteristicsofthepenstocknumberitemparametertypecontrollersizeheadalongpipediameterpipelength11hydropowerstationpenstockopen-airexposedpipe,singlepipejointwatersupply1.3M931m0.8M8.3*2m22hydropowerstationpenstockopen-airexposedpipe,singlepipejointwatersupply1.4m1063.506m0.8M10*2mtable1-2hydropowerstationMaincharacteristicsofhydraulicmetalstructurenumberprojectnamegate,trashrack,door(gate...Pressurepipeandthemetalstructureinstallation9.1mainengineeringprofileyongxingriverlevelhydropowerstationpressurepipepipelineplaneShangalongRidgeislinelayout,andslopesurfacecontourclosevertical,GuanPowithoriginalgroundlinechanges,usedopentypeMingtube,singletubejointwaterway,competentdiameter1.3M,long931.00m,tworootnon-symmetric"Bu"typesupporttube,diameter0.8M,singlerootlong8.3M.Competenttoestablish12townPier,107buttress,telescopicsection11.SupportPierspacing8M,side-slidingbearing.Townpierfortheclosed-endstructureofgravity,basesurfaceintobedrock,pipeexcavationslope1:0.75withM5groutedrubbleslopeprotection,0.3M,bottomsidesewer,0.25mwide,deep0.3m,M5groutedrubblemasonry,setmaintenancestepladderontheleftside,1.0Mwide.Yongxinghe-?hydropowerstationpenstockpipesarrangedalongtheridgelineontheplane,andnearlyverticalslopecontourlines,GuanPochangeswiththeoriginalgroundline,withshallowbackfill-pipe,single-pipewatersupply,thecompetent1.4m,long1063.506m,twoasymmetric"y"pipe,diameter0.8M,single10m.Competenttoestablish12townPier,8expansionjoint.Townpierfortheclosed-endstructureofgravity,placedonsoftrockbasesurface,pipeconcreteC20onapedestal.Pipetrenchexcavationslope1:0.75,aftertheinstallationofsteeltube,compactedgravel对值相等。(因为它们到原点的距离相等)2、绝对值的代数意义是什么,答:(1)一个正数的绝对值是它本身。(2)一个负数的绝对值是它的相反数。(3)0的绝对值是0。3、一个数a的绝对值如何表示,(1)如果a,0，那么|a|=a;(2)如果a,0，那么|a|=-a;(3)如果a=0，那么|a|=0。4、两个负数，绝对值大的反而小。5、绝对值最小的数是什么,(是,)。什么数的绝对值是它的本身,(正数和0)。什么数的绝对值是它的相反数,(负数)。installationpartmainincludingYunnanprovincetengchongCountyyongxingRiverprimaryandsecondaryhydropowerstationintheofpressurepipeandthepowerstationmetalstructure,whichlevelpowerstationpressurepipetotalabout562t(containingannex);IIlevelpowerstationpressurepipeabout733t(containingannex);levelpowerstationmetalstructureabout52.5t,containingdischargeGate2hole,rushedsandGate1hole,watermouthworkdoorandthestoppeddirtgatethe1hole,Qianpoolworkdoorandthestoppeddirtgatethe1hole;Secondarypowerstationmetaljunctionatabout19.5t,containingsandGate1hole,waterinletwatergateandtrashthe1hole;theirauxiliaryhoistequipmentandelectricalequipment.Concretepressurepipe,gate,trashandhoistingdeviceprojectpropertylist1-1~1-3.Table1-1themaincharacteristicsofthepenstocknumberitemparametertypecontrollersizeheadalongpipediameterpipelength11hydropowerstationpenstockopen-airexposedpipe,singlepipejointwatersupply1.3M931m0.8M8.3*2m22hydropowerstationpenstockopen-airexposedpipe,singlepipejointwatersupply1.4m1063.506m0.8M10*2mtable1-2hydropowerstationMaincharacteristicsofhydraulicmetalstructurenumberprojectnamegate,trashrack,door(gate...Pressurepipeandthemetalstructureinstallation9.1mainengineeringprofileyongxingriverlevelhydropowerstationpressurepipepipelineplaneShangalongRidgeislinelayout,andslopesurfacecontourclosevertical,GuanPowithoriginalgroundlinechanges,usedopentypeMingtube,singletubejointwaterway,competentdiameter1.3M,long931.00m,tworootnon-symmetric"Bu"typesupporttube,diameter0.8M,singlerootlong8.3M.Competenttoestablish12townPier,107buttress,telescopicsection11.SupportPierspacing8M,side-slidingbearing.Townpierfortheclosed-endstructureofgravity,basesurfaceintobedrock,pipeexcavationslope1:0.75withM5groutedrubbleslopeprotection,0.3M,bottomsidesewer,0.25mwide,deep0.3m,M5groutedrubblemasonry,setmaintenancestepladderontheleftside,1.0Mwide.Yongxinghe-?hydropowerstationpenstockpipesarrangedalongtheridgelineontheplane,andnearlyverticalslopecontourlines,GuanPochangeswiththeoriginalgroundline,withshallowbackfill-pipe,single-pipewatersupply,thecompetent1.4m,long1063.506m,twoasymmetric"y"pipe,diameter0.8M,single10m.Competenttoestablish12townPier,8expansionjoint.Townpierfortheclosed-endstructureofgravity,placedonsoftrockbasesurface,pipeconcreteC20onapedestal.Pipetrenchexcavationslope1:0.75,aftertheinstallationofsteeltube,compactedgravel6、绝对值是,的数是，绝对值是,的数是。绝对值是-,的数有没有,(没有)。绝对值不大于,的数有多少,(无数个)。绝对值不大于,的整数有，正整数有，负整数有。根据上面的例子，我们可以看出:任意一个正数的绝对值，都有两个——它们是互为相反数;没有一个数的绝对值会等于负数。7、如果|,|,,.,,那么x=。|y-,|=6，y=。如果|-,|=|-5|，那么,=。满足|,|?3的负整数有。8、如果|,-,|+|,-,|,,，那么,,，,,。1-3有理数的大小installationpartmainincludingYunnanprovincetengchongCountyyongxingRiverprimaryandsecondaryhydropowerstationintheofpressurepipeandthepowerstationmetalstructure,whichlevelpowerstationpressurepipetotalabout562t(containingannex);IIlevelpowerstationpressurepipeabout733t(containingannex);levelpowerstationmetalstructureabout52.5t,containingdischargeGate2hole,rushedsandGate1hole,watermouthworkdoorandthestoppeddirtgatethe1hole,Qianpoolworkdoorandthestoppeddirtgatethe1hole;Secondarypowerstationmetaljunctionatabout19.5t,containingsandGate1hole,waterinletwatergateandtrashthe1hole;theirauxiliaryhoistequipmentandelectricalequipment.Concretepressurepipe,gate,trashandhoistingdeviceprojectpropertylist1-1~1-3.Table1-1themaincharacteristicsofthepenstocknumberitemparametertypecontrollersizeheadalongpipediameterpipelength11hydropowerstationpenstockopen-airexposedpipe,singlepipejointwatersupply1.3M931m0.8M8.3*2m22hydropowerstationpenstockopen-airexposedpipe,singlepipejointwatersupply1.4m1063.506m0.8M10*2mtable1-2hydropowerstationMaincharacteristicsofhydraulicmetalstructurenumberprojectnamegate,trashrack,door(gate...Pressurepipeandthemetalstructureinstallation9.1mainengineeringprofileyongxingriverlevelhydropowerstationpressurepipepipelineplaneShangalongRidgeislinelayout,andslopesurfacecontourclosevertical,GuanPowithoriginalgroundlinechanges,usedopentypeMingtube,singletubejointwaterway,competentdiameter1.3M,long931.00m,tworootnon-symmetric"Bu"typesupporttube,diameter0.8M,singlerootlong8.3M.Competenttoestablish12townPier,107buttress,telescopicsection11.SupportPierspacing8M,side-slidingbearing.Townpierfortheclosed-endstructureofgravity,basesurfaceintobedrock,pipeexcavationslope1:0.75withM5groutedrubbleslopeprotection,0.3M,bottomsidesewer,0.25mwide,deep0.3m,M5groutedrubblemasonry,setmaintenancestepladderontheleftside,1.0Mwide.Yongxinghe-?hydropowerstationpenstockpipesarrangedalongtheridgelineontheplane,andnearlyverticalslopecontourlines,GuanPochangeswiththeoriginalgroundline,withshallowbackfill-pipe,single-pipewatersupply,thecompetent1.4m,long1063.506m,twoasymmetric"y"pipe,diameter0.8M,single10m.Competenttoestablish12townPier,8expansionjoint.Townpierfortheclosed-endstructureofgravity,placedonsoftrockbasesurface,pipeconcreteC20onapedestal.Pipetrenchexcavationslope1:0.75,aftertheinstallationofsteeltube,compactedgravel1、数轴上数的大小有什么位置关系,答:在数轴上表示的两个数，右边的数总比左边的数大。根据这点，我们可以利用数轴比较数的大小。正数都大于0，负数都小于0，正数大于一切负数。2、两个负数比较大小，绝对值大的反而小。1-4有理数的加减1-4-1有理数的加法1、有理数加法法则的内容是什么,(1)同号两数相加，取相同的符号，并把绝对值相加。(2)绝对值不相等的异号两数相加，取绝对值较大的加数的符号，并用较大的绝对值减去较小的绝对值。互为相反数的两个installationpartmainincludingYunnanprovincetengchongCountyyongxingRiverprimaryandsecondaryhydropowerstationintheofpressurepipeandthepowerstationmetalstructure,whichlevelpowerstationpressurepipetotalabout562t(containingannex);IIlevelpowerstationpressurepipeabout733t(containingannex);levelpowerstationmetalstructureabout52.5t,containingdischargeGate2hole,rushedsandGate1hole,watermouthworkdoorandthestoppeddirtgatethe1hole,Qianpoolworkdoorandthestoppeddirtgatethe1hole;Secondarypowerstationmetaljunctionatabout19.5t,containingsandGate1hole,waterinletwatergateandtrashthe1hole;theirauxiliaryhoistequipmentandelectricalequipment.Concretepressurepipe,gate,trashandhoistingdeviceprojectpropertylist1-1~1-3.Table1-1themaincharacteristicsofthepenstocknumberitemparametertypecontrollersizeheadalongpipediameterpipelength11hydropowerstationpenstockopen-airexposedpipe,singlepipejointwatersupply1.3M931m0.8M8.3*2m22hydropowerstationpenstockopen-airexposedpipe,singlepipejointwatersupply1.4m1063.506m0.8M10*2mtable1-2hydropowerstationMaincharacteristicsofhydraulicmetalstructurenumberprojectnamegate,trashrack,door(gate...Pressurepipeandthemetalstructureinstallation9.1mainengineeringprofileyongxingriverlevelhydropowerstationpressurepipepipelineplaneShangalongRidgeislinelayout,andslopesurfacecontourclosevertical,GuanPowithoriginalgroundlinechanges,usedopentypeMingtube,singletubejointwaterway,competentdiameter1.3M,long931.00m,tworootnon-symmetric"Bu"typesupporttube,diameter0.8M,singlerootlong8.3M.Competenttoestablish12townPier,107buttress,telescopicsection11.SupportPierspacing8M,side-slidingbearing.Townpierfortheclosed-endstructureofgravity,basesurfaceintobedrock,pipeexcavationslope1:0.75withM5groutedrubbleslopeprotection,0.3M,bottomsidesewer,0.25mwide,deep0.3m,M5groutedrubblemasonry,setmaintenancestepladderontheleftside,1.0Mwide.Yongxinghe-?hydropowerstationpenstockpipesarrangedalongtheridgelineontheplane,andnearlyverticalslopecontourlines,GuanPochangeswiththeoriginalgroundline,withshallowbackfill-pipe,single-pipewatersupply,thecompetent1.4m,long1063.506m,twoasymmetric"y"pipe,diameter0.8M,single10m.Competenttoestablish12townPier,8expansionjoint.Townpierfortheclosed-endstructureofgravity,placedonsoftrockbasesurface,pipeconcreteC20onapedestal.Pipetrenchexcavationslope1:0.75,aftertheinstallationofsteeltube,compactedgravel数相加得0。(3)一个数同0相加，仍得这个数。2、加法交换律:两个数相加，交换加数的位置，和不变。字母表达式是:a+b=b+a。3、加法结合律:三个数相加，先把前两个数相加，或者先把后两个数相加，和不变。字母表达式是:(a+b)+c=a+(b+c)。思考题:4、两个正数相加，和一定为()，两个负数相加，和一定为()。而正数和负数相加，和可能是(正数、负数或0)，为什么,5、如果a,0，b,0，那么a+b0。为什么,如果a,0，b,0，|a|,|b|，那么a+b0。如果a,0，b,0，|a|,|b|，那么a+b0。installationpartmainincludingYunnanprovincetengchongCountyyongxingRiverprimaryandsecondaryhydropowerstationintheofpressurepipeandthepowerstationmetalstructure,whichlevelpowerstationpressurepipetotalabout562t(containingannex);IIlevelpowerstationpressurepipeabout733t(containingannex);levelpowerstationmetalstructureabout52.5t,containingdischargeGate2hole,rushedsandGate1hole,watermouthworkdoorandthestoppeddirtgatethe1hole,Qianpoolworkdoorandthestoppeddirtgatethe1hole;Secondarypowerstationmetaljunctionatabout19.5t,containingsandGate1hole,waterinletwatergateandtrashthe1hole;theirauxiliaryhoistequipmentandelectricalequipment.Concretepressurepipe,gate,trashandhoistingdeviceprojectpropertylist1-1~1-3.Table1-1themaincharacteristicsofthepenstocknumberitemparametertypecontrollersizeheadalongpipediameterpipelength11hydropowerstationpenstockopen-airexposedpipe,singlepipejointwatersupply1.3M931m0.8M8.3*2m22hydropowerstationpenstockopen-airexposedpipe,singlepipejointwatersupply1.4m1063.506m0.8M10*2mtable1-2hydropowerstationMaincharacteristicsofhydraulicmetalstructurenumberprojectnamegate,trashrack,door(gate...Pressurepipeandthemetalstructureinstallation9.1mainengineeringprofileyongxingriverlevelhydropowerstationpressurepipepipelineplaneShangalongRidgeislinelayout,andslopesurfacecontourclosevertical,GuanPowithoriginalgroundlinechanges,usedopentypeMingtube,singletubejointwaterway,competentdiameter1.3M,long931.00m,tworootnon-symmetric"Bu"typesupporttube,diameter0.8M,singlerootlong8.3M.Competenttoestablish12townPier,107buttress,telescopicsection11.SupportPierspacing8M,side-slidingbearing.Townpierfortheclosed-endstructureofgravity,basesurfaceintobedrock,pipeexcavationslope1:0.75withM5groutedrubbleslopeprotection,0.3M,bottomsidesewer,0.25mwide,deep0.3m,M5groutedrubblemasonry,setmaintenancestepladderontheleftside,1.0Mwide.Yongxinghe-?hydropowerstationpenstockpipesarrangedalongtheridgelineontheplane,andnearlyverticalslopecontourlines,GuanPochangeswiththeoriginalgroundline,withshallowbackfill-pipe,single-pipewatersupply,thecompetent1.4m,long1063.506m,twoasymmetric"y"pipe,diameter0.8M,single10m.Competenttoestablish12townPier,8expansionjoint.Townpierfortheclosed-endstructureofgravity,placedonsoftrockbasesurface,pipeconcreteC20onapedestal.Pipetrenchexcavationslope1:0.7