1无线基站罗姆(ROHM)针对无线基站推出了多款解决方案,包括一系列高耐压MOSFET和高效率DC/DC转换器等,有助于降低功耗。Si CMOSFET具有高耐压、高速开关、低导通电阻的特性,即使在高温环境下也能显示出色的电器特性,有助于大幅降低开关...1无线基站罗姆(ROHM)针对无线基站推出了多款解决方案,包括一系列高耐压MOSFET和高效率DC/DC转换器等,有助于降低功耗。Si CMOSFET具有高耐压、高速开关、低导通电阻的特性,即使在高温环境下也能显示出色的电器特性,有助于大幅降低开关损耗和周边零部件的小型化。罗姆备有650 V、1 200 V、1 700 V Si C MOSFET产品。展开更多
12H－Dibenzo d,g 1,3 dioxocin－6－carboxylic acid is a patented herbicide (US4976770)With good pre－and post－emergence activity on dicot weeds and sedges． Structure activity studies were initiated with the goal of d...12H－Dibenzo d,g 1,3 dioxocin－6－carboxylic acid is a patented herbicide (US4976770)With good pre－and post－emergence activity on dicot weeds and sedges． Structure activity studies were initiated with the goal of discovering more synthetically accessible analogs with improved unit activity and crop－weed selectivity．An improved procedure to prepare the lead compound was developed．Analogs were prepared in which both the tricyclic core and the carboxylic acid function were varied．The synthesis and screening results of these analogs will be presented．展开更多
Time-varying frequency selective attenuation and colored noises are unfavorable characteristics of power line communication(PLC) channels of the low voltage networks.To overcome these disadvantages,a novel real-time d...Time-varying frequency selective attenuation and colored noises are unfavorable characteristics of power line communication(PLC) channels of the low voltage networks.To overcome these disadvantages,a novel real-time dynamic spectrum management(DSM) algorithm in orthogonal frequency division multiplexing(OFDM)-based high-speed narrow-band power line communication(HNPLC) systems is proposed,and the corresponding FPGA circuit is designed and realized.Performance of the proposed DSM is validated with a large amount of network experiments under practical PLC circumstance.As the noise in each narrow subcarrier is approximately Gaussian,the proposed DSM adopts the BER/SER expression formulized via the AWGN channel to provide a handy and universal strategy for power allocation.The real-time requirement is guaranteed by choosing subcarriers in group and employing the same modulation scheme within each transmission.These measures are suitable for any modulation scheme no matter the system criterion is to maximize data rate or minimize power/BER.Algorithm design and hardware implementation of the proposed DSM are given with some flexible and efficient conversions.The DSM circuit is carried out with Xilinx KC705.Simulation and practical experiments validate that the proposed real-time DSM significantly improves system performance.展开更多
文摘1无线基站罗姆(ROHM)针对无线基站推出了多款解决方案,包括一系列高耐压MOSFET和高效率DC/DC转换器等,有助于降低功耗。Si CMOSFET具有高耐压、高速开关、低导通电阻的特性,即使在高温环境下也能显示出色的电器特性,有助于大幅降低开关损耗和周边零部件的小型化。罗姆备有650 V、1 200 V、1 700 V Si C MOSFET产品。
文摘12H－Dibenzo d,g 1,3 dioxocin－6－carboxylic acid is a patented herbicide (US4976770)With good pre－and post－emergence activity on dicot weeds and sedges． Structure activity studies were initiated with the goal of discovering more synthetically accessible analogs with improved unit activity and crop－weed selectivity．An improved procedure to prepare the lead compound was developed．Analogs were prepared in which both the tricyclic core and the carboxylic acid function were varied．The synthesis and screening results of these analogs will be presented．
基金Supported by the Tsinghua University International Science and Technology Cooperation Project(No.20133000197,20123000148)
文摘Time-varying frequency selective attenuation and colored noises are unfavorable characteristics of power line communication(PLC) channels of the low voltage networks.To overcome these disadvantages,a novel real-time dynamic spectrum management(DSM) algorithm in orthogonal frequency division multiplexing(OFDM)-based high-speed narrow-band power line communication(HNPLC) systems is proposed,and the corresponding FPGA circuit is designed and realized.Performance of the proposed DSM is validated with a large amount of network experiments under practical PLC circumstance.As the noise in each narrow subcarrier is approximately Gaussian,the proposed DSM adopts the BER/SER expression formulized via the AWGN channel to provide a handy and universal strategy for power allocation.The real-time requirement is guaranteed by choosing subcarriers in group and employing the same modulation scheme within each transmission.These measures are suitable for any modulation scheme no matter the system criterion is to maximize data rate or minimize power/BER.Algorithm design and hardware implementation of the proposed DSM are given with some flexible and efficient conversions.The DSM circuit is carried out with Xilinx KC705.Simulation and practical experiments validate that the proposed real-time DSM significantly improves system performance.
