简介:Ignitionmodelsoftestedmaterialhaveimportantsignificancetofireprevention.Inordertoknowheattransferofthermalthinmaterialinfiredisaster,startingfromthelawofconservationofenergy,simplifyingheatcapacityintoaconstantaccordingtoDulong-Petitlaw,andthreecalculationformulasofignitiontimeofthermalthinmaterialinaconstantheatfluxwererespectivelyobtainedundertheconditionsofignoringheatloss,linearprocessingheatlossandconsideringthermalradiation.Therelationbetweentheignitiontimeandthethermalcurrentintensitywasdiscussed.
简介:Themanufacturetechnologiesoftwokindsofbamboolaminatedpanelandtheirphysical-mechanicalpropertieshavebeenstudiedinthepaper.ThespeciesofbambooaretheD.yunnanicusHsuehetD.Z.LiinYunnanProvinceandP.heterocyclavar.pubescensOhwiinZhejiangProvince.Thedataareofferedinordertoprovideprooftoproducearchitecturalpanelbybamboomaterials.Theresultsshowasfollows:Laminatedbamboopanelcanbeproducedbythereconstructiontechnology,andthemechanicalprope...
简介:Twokindsofbigsympodialbamboo,D.YunnanicusHsuehandWhangee(D.MembranaceusMunro)andtheirphysicalandmechanicalpropertieshavebeenstudiedinthepaper.TheresultsshowedthatthewhangeehasbetterphysicalpropertiesthanthatoftheYunnanicus,suchashigherdensity,lowertangentialandlongitudinaldryshrinkages.ThatalsoshowedthatWhangeehasstrongermechanicalpropertiesinMORandMOE,compressivestrengthandshearstrengthparalleltothegrain.Comparedwithsomewoodspeciesusedinarchitecture,thephysicalandmechanicalpropertiesofthetwokindshavereachedtherequirementofsomewoodarchitecturestructurematerials.
简介:选取北京天坛公园内4种绿地结构类型及13种不同配置模式(一种为水泥铺装空白地面对照)为研究对象,开展了对公园绿地的空气负离子、PM_(2.5)两种主要生态保键因子的单项保键效应定量研究与评价,结果表明:天坛公园春夏两季各样地的负离子浓度日变化均呈早晚低中午高的单峰趋势,秋冬两季变化趋势没有明显的规律。四季负离子浓度大小排序为:夏季〉春季〉秋季〉冬季,各样地中夏季最高平均值为1577.04个·cm~(-3),冬季最低平均值为311.94个·cm~(-3);PM_(2.5)浓度日变化除春季外,其他三季的均呈早晚高、中午低的日变化趋势;各样地消减能力排序为:春季〉夏季〉秋季〉冬季,消减率范围为0.01%~12.98%;各类绿地结构类型生态保健功能效应排序为乔-灌-草最好,乔-草较好,灌-草和纯草类型次之。绿地与裸地两种样地在春夏秋三季节里在8:00~18:00左右均适合进行户外游憩活动,但最佳游憩时间不同。冬季只有绿地内10:00~12:00时间段内在适宜户外游憩。