In this study,flower-like MoS2 constructed by nanosheets was synthesized by a simple hydrothermal method.The hydrothermal process was optimized and the effects of hydrothermal condition,including reaction temperature,...In this study,flower-like MoS2 constructed by nanosheets was synthesized by a simple hydrothermal method.The hydrothermal process was optimized and the effects of hydrothermal condition,including reaction temperature,reaction time and the ratio of Mo source to S source(Mo:S)in precursor,on microwave absorption performances and dielectric properties were investigated.Our results showed that when the reaction temperature was 180℃,the reaction time was 18 h,and the Mo:S was 1:3.5,the synthesized MoS2 had the best performance:Its minimum reflection loss could reach-55.78 dB,and the corresponding matching thickness was 2.30 mm with a wide effective bandwidth of 5.17 GHz.Further researches on the microwave absorption mechanism revealed that in addition to the destructive interference of electromagnetic waves,various polarization phenomena such as defect dipole polarization were the main reasons for microwave loss.We believe that MoS2 is a candidate for a practical microwave absorbent.展开更多
基金financially supported by the National Natural Science Foundation of China(No.21403298)。
文摘In this study,flower-like MoS2 constructed by nanosheets was synthesized by a simple hydrothermal method.The hydrothermal process was optimized and the effects of hydrothermal condition,including reaction temperature,reaction time and the ratio of Mo source to S source(Mo:S)in precursor,on microwave absorption performances and dielectric properties were investigated.Our results showed that when the reaction temperature was 180℃,the reaction time was 18 h,and the Mo:S was 1:3.5,the synthesized MoS2 had the best performance:Its minimum reflection loss could reach-55.78 dB,and the corresponding matching thickness was 2.30 mm with a wide effective bandwidth of 5.17 GHz.Further researches on the microwave absorption mechanism revealed that in addition to the destructive interference of electromagnetic waves,various polarization phenomena such as defect dipole polarization were the main reasons for microwave loss.We believe that MoS2 is a candidate for a practical microwave absorbent.
文摘为了实现模拟集成电路版图设计的自动化,提出一种称为金属-氧化物-半导体场效应晶体管阵列的版图布局方法。90 nm/1. 2 V互补式MOS的测试元件组(TEG)芯片被开发用以实验采样,芯片搭载多种导电沟道分割形式的多指栅晶体管,晶体管在电路的版图设计中以不同的布局形态呈现。这些晶体管的电气参数被测试并抽取,用以分析和评价其直流性能。以二级模拟运算放大器为实验电路,分别采用晶体管阵列和全定制方式进行版图设计,从工艺波动性和版图面积两方面进行对比。成品实测结果表明:以晶体管阵列方式实现共源共栅运放电路时,10枚TEG芯片的平均失调电压为4. 48 m V,对比手工版图的5. 59 m V,抗波动性能约提升了20%,显示了晶体管阵列版图设计方法的有效性。
