简介:Anewrectangularpulsetriggergeneratorhasbeendevelopedwhichcangeneratetwo10kVpulseswitharisetimelessthan1ns,ajitterof0.2nsandawidthofabout10nsand40ns,respectively.Thisgeneratorusestwopolymer-foilswitchesand25ohmBlumleintransmissionlinescomposedoftwo-parallelstandardcoaxialcablesdischargingintotwo50ohmoutputcables.Thepulsewidthandthedelaybetweentwopulsescanbeadjustedbychangingthelengthofthecables.
简介:InChina’sthreenorthernregionsoftheNorthwest,NorthandNortheast(3Ns),thereare1.33millionsqkmofdesertandsandland,forminga5,000-km-longwind-sandbelt.In1978,theChinesegovernmentdecidedtobuildthe"3Ns"shelterbeltnetwork.Theprojectcovers13provinces,autonomousregionsandcitiesincludingXinjiang,Qinghai,Gansu,Ningxia,Shaanxi,InnerMongolia,Shanxi,Hebei,Beijing,Tianjin,Liaoning,JilinandHeilongjiang,eoveringanareaof4.06millionsqkm,42%ofthecountry’stotalland.Itplanstocompletetheprojectin73years,inthreephases:thefirstphaseis