，波波夫无意之中发现一根导线搭在金属屑检波器上。他把导线拿开，电铃便不响了；他把实验距离缩小到原来那么近，电铃又响了起来。波波夫喜出望外，连忙把导线接到金属屑检波器的一头，并把检波器的另一头接上。经过再次试验，结果表明使用天线后，信号传递距离剧增。无线电天线由此而问世。天线分类按工作性质可分为：发射天线和接收天线。按用途可分为：通信天线、广播天线、电视天线、雷达天线等。按方向性可分为：全向天线和定向天线等。
PV032R1K1T1NGLC
PV032R1K4T1NFHS
PV032R1K8S1NFWS
PV032R1K8T1NMMC
PV032R1K1T1WFDS
PV032R1K1AYNMTP
PV032R1K1T1NHCC
PV032R1K1T1WMM1
PV032R1K1AYNMRZ
PV032R1K8T1NFWS
PV032R1K1A4NFTZ
PV032R1K1T1VMMC
PV032R1K1T1NFPV
PV032R1K1A1VFDS
PV032L1E3C1NFWS
PV032R1K1T1NELB
PV032L1K1T1NFWS
PV032R1K1B1NFDS
PV032RAK1T1NF
PV032R1L1B1NFWS
PV032R1K1T1NFPG
PV032R1K1S1NFWS
PV032L1K1T1NMMC
PV032R1K1T1NMRZ
PV032R1K1T1VFDS
PV032R1K1T1N10045
PV032R1K1AYNMT1
PV032R1K8T1N001
PV032R1K1T1NHLC
PV032R1K4T1NFR1
PV032R9K1T1NMMC
PV032R1K1A4VFRZ
PV032R1K1T1NFRZ
PV032R1K1T1NMMK
PV032R1L1T1NMMC
PV032R1K4T1NMR1
PV032R1K1T1WMR1
PV032R9K1T1NMMCK
PV032R1K1T1NE1B
PV032R1K1T1NKLC
PV040R1K8T1NMMC
PV040L1K1T1NFWS
PV040R1K1T1NFRC
PV040R1K1T1NFFP
PV040R1K4T1NMR1
PV040R1K1T1NMR1
PV040R1K1T1NFR1
PV040R1K4T1NMMC
PV040R1K1T1NFDS
PV040R1K1T1NFF1
PV040R1K1T1NMRZ
PV040R1K1AYNMRZ
PV040R1K4T1NFHS
PV040R1K1T1WFDS
PV040R1K8T1VMMC
PV040R1K8T1N001
PV040R9K1T1NMMC
PV040R1K4T1NFR1
PV040R1K1T1N001
PV040R1K8T1NFWS
PV040R1K1T1VFDS
PV040R1K1A4NFRZ
PV040R1K1T1NMRC
PV040R1K1T1NMM1
PV040R1K1T1WMM1
PV040R1K1T1NMRK
PV040R1K1T1NHCC
PV040R1K1T1NMF1
PV040R1K1JHNMMC
PV040L1K1T1NMMC
PV040R1K1S1NFWS
PV040R1L1T1NMMC
PV040R1D8T1N001
PV040R1K1T1NMFC
尤其是在汽车工况发生急剧变化，如汽车突然制动或加速时，其检测精度较差，因而影响了D型EFI系统在现代汽车中的推广。取而代之的是L型EFI系统，它是用空气流量计直接测量发动机吸入的空气量，因而有较高的检测精度。D型和L型EFI系统均采用多点喷射（MPI），即每个气缸的进气歧管设一个喷油器，因而系统体结构比较复杂，制造成本较高。目前*的是MONO系统，该系统是一种低压喷射系统，即单点喷射（SPI）系统，它只在进气管设一个喷油器进行集中控制，使结构大为简化。
PV040R1K1T1NFWS
PV040R1K1T1WFR1
PV040R1K1T1NKLC
PV040R9K1T1NFWS
PV040R1K1T1NFFC
PV040R1K1T1NF
PV040R1K1T1N100
PV040R1K1T1WMR1
PV040R1K1T1NFRZ
PV040R1K1T1WMRC
PV040R1K1T1NMMK
PV040R1K1T1NMMC
PV040R1K1T1VMMC
PV040R1K1T1NFHS
PV040R1K1T1NGLC
PV040R1K1T1NHLC
PV040R1K1T1WMMC
PV040L1L1T1NFWS
PV040R1K1T1NMLC
PV040R1D1T1NGCC
PV040R1K1T1NELA
PV040R9K1T1NMMCK0188
PV046R1K1T1N001
PV046R1K1T1N100
PV046R1K1T1NFDS
PV046R1K1T1NFR1
PV046R1K1T1NFHS
PV046R1K1T1NMMC
PV046R1K1T1NMM1
PV046R1K1T1NMRC
PV046R1K1T1NFWS
PV046R1K1T1NFRC
PV046R1K1T1NFF1
PV046R1D1T1NFWS
PV046R1D3T1NFFC
PV046R1K1A1NF
PV046L1K1A1NFHS
PV046R1K1B1NFDS
PV046R1D1T1NHCC
PV046R1K1T1NFFC
PV046R1K1T1NMFC
PV046R1K1T1NMF1
PV046R9K1T1NMMC
PV046R1K1AYNMRC
PV046R1K1JHNMMC
PV046R9K1T1NFWS
PV046R1K4T1NMR1
PV046R1K4T1NFHS
PV046L1K1T1NFWS
PV046R1K1S1NFWS
PV046R1K1T1WFDS
PV046R1K1T1NMRZ
PV046R1K1T1EMMC
PV046R1K1T1WMMC
PV046R1K1T1NFFP
PV046R1K1A4NFRC
PV046R1K1T1VFDS
PV046R1K8T1NFWS
PV046R1K1T1WMM1
PV046L1K1T1NMMC
PV046R1K8T1VMMC
PV046R1K8T1NMMC
PV046R1K1T1NF
PV046R1K1AYNMRZ
PV046R1K1T1NHLC
PV046R1K1T1NMMK
PV046R1K1T1NKLC
PV046R1K1T1NMR1
PV046R1K1T1NFRZ
PV046R1K1T1WFR1
PV046R1K4T1NFR1
PV046R1K1T1WMR1
PV046R1K1T1NMRK
PV046R1K1T1WMRC
PV046R1K1T1NHCC
PV046R1K1T1VMMC
PV046R1K1T1NGLC
PV046R1L1T1NMMC
PV046R1K8T1N001
PV046R1K4T1NMMC
PV046R1K1T1NMMCX5934
PV063R1K1T1NMF1
PV063R1K1T1NMMC
PV063R1K1T1NMMK
PV063R9L1TNMPCK0
PV063R1K1A1VFPR
PV063R1K1C1NFWS
PV063R2K1T1N001
PV063R9L1T1NFWS
PV063R1K1A1NFHS
PV063R1K1T1NFFP
PV063R1K1T1NFPR
PV063R1K1T1NGLC
PV063R1K1T1N001
PV063R1K1T1N100
PV063R1K1T1NFDS
当我们用台式硬度计测量洛氏硬度时，硬度计压头是金刚石锥体，压头（锥顶直径为0.4毫米）与被测表面的接触面积较小。加载时，压头很容易穿透挤压层，因此硬度的测量偏差较小。试验证明，测量偏差一般在5HRC以内。用台式硬度计测量布氏硬度时，硬度计压头是钢球压头，压头与被测表面的接触面积较大。加载时，压头必须克服挤压层的较大阻力才能被测表面，这就使硬度计压头的量不够，所压得的圆形压痕也随之变小，致使相应的硬度值偏高于其真实值。
