基本信息
| 标准名称： | 450MHz FDMA无线接入系统技术要求和测量方法 |
| 英文名称： | Technical performances and test methods of FDMA wireless access systems for 450MHz |
| 中标分类： |
通信、广播 >>
通信设备 >>
移动通信设备 |
| 发布部门： | 中华人民共和国信息产业部 |
| 发布日期： | 1999-03-19 |
| 实施日期： | 1999-07-01 |
| 首发日期： | 1900-01-01 |
| 作废日期： | 1900-01-01 |
| 提出单位： | 邮电部电信科学研究规划院 |
| 归口单位： | 邮电部电信科学研究规划院 |
| 起草单位： | 邮电部第四研究所 |
| 起草人： | 陈小舟 |
| 出版社： | 人民邮电出版社 |
| 出版日期： | 1999-07-01 |
| 页数： | 15页 |
适用范围
本标准规定了450MHZ频段、频分多址（FDMA）无线接入系统的技术要求和测量方法。本标准适用于450MHZ无线接入系统的研制、生产和检验，其它FDMA无线系统也可参照执行。
前言
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目录
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引用标准
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所属分类： 通信 广播 通信设备 移动通信设备
【英文标准名称】:StandardTestMethodforDeterminingJ-RCurvesofPlasticMaterials
【原文标准名称】:塑料材料J-R曲线测定的标准试验方法
【标准号】:ASTMD6068-2010
【标准状态】:现行
【国别】:
【发布日期】:2010
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:D20.10
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:裂纹扩展阻力;断裂韧性;塑料;高聚物;破裂-裂纹扩展;断口测试-塑料;J-R曲线;荷载试验-塑料;塑料材料;
【英文主题词】:crackgrowthresistance;fracturetoughness;J-Rcurves;plastics;polymers;Cracking--crackgrowth;Fracturetesting--plastics;J-Rcurves;Loadingtests--plastics;Plasticmaterials;Polymers
【摘要】:AJ-Rcurveproducedinaccordancewiththistestmethodcharacterizesthecrackgrowthresistancesofawiderangeoftoughpolymersandpolymerblends(1-5)thatcannotbeobtainedinsufficientsizeandthicknessforvalidcharacterizationbylinearelasticfracturemechanicsinTestMethodsD5045.TheJ-Rcurvecharacterizes,withinthelimitssetforthinthistestmethod,theresistanceofapolymericmaterialtoslowstablecrackgrowthafterinitiationfromapreexistingsharpflaw.AJ-Rcurvecanbeusedasanindexofmaterialtoughnessforblendoralloydesign,materialselection,materialsprocessing,andqualityassurance(6).TheJ-RcurvesfrombendspecimensrepresentlowerboundestimatesofJcapacityasafunctionofcrackextension,andhavebeenobservedtobeconservativerelativetothoseobtainedfromspecimenconfigurationsundertensileloading.TheJ-Rcurvesforagivenmaterialofconstantmicrostructuretendtoexhibitlowerslope(flatter)withincreasingthickness.Thus,itisrecommendedthatthelargestpossiblespecimenwithrepresentativemicrostructurebeused.TheJ-Rcurvecanbeusedtoassessthestabilityofcracksinstructuresinthepresenceofductiletearing,withawarenessofthedifferencesthatmayexistbetweenlaboratorytestandfieldconditions.AJ-Rcurvemaydependontheorientationandpropagationofthecrackinrelationtotheanisotropyofthematerialwhichmaybeinducedbyspecimenfabricationmethods.Becauseofthepossibilityofratedependenceofcrackgrowthresistance,J-Rcurvescanbedeterminedatdisplacementratesotherthanthatspecifiedinthistestmethod(7).1.1ThistestmethodcoversthedeterminationoftheJ-integralversuscrackgrowthresistance(J-R)curvesforpolymericmaterials.1.2Thistestmethodisintendedtocharacterizetheslow,stablecrackgrowthresistanceofbend-typespecimensinsuchamannerthatitisgeometryinsensitivewithinlimitssetforthinthistestmethod.1.3Therecommendedspecimensarethethree-pointbend(SE(B))andpin-loadedcompacttension(C(T))specimens.Bothspecimenshavein-planedimensionsofconstantproportionalityforallsizes.Specimenconfigurationsotherthanthoserecommendedinthistestmethodmayrequiredifferentproceduresandvalidityrequirements.1.4Thistestmethoddescribesamultiplespecimenmethodthatrequiresopticalmeasurementofcrackextensionfromfracturesurfaces.Itisnotrecommendedforusewithmaterialsinwhichthecrackfrontcannotbedistinguishedfromadditionaldeformationprocessesinadvanceofthecracktip.1.5ThevaluesstatedinSIunitsaretoberegardedasthestandard.1.6Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.Note18212;ThereisnoequivalentISOstandard.
【中国标准分类号】:G31
【国际标准分类号】:83_040_01
【页数】:8P.;A4
【正文语种】: