This paper presents a wide-bandwidth back-illuminated modified uni-traveling-carrier photodiode(MUTC-PD)packaged with standard WR-5 rectangular waveguide for high-speed wireless communications.With optimized epitaxy s...This paper presents a wide-bandwidth back-illuminated modified uni-traveling-carrier photodiode(MUTC-PD)packaged with standard WR-5 rectangular waveguide for high-speed wireless communications.With optimized epitaxy structure and coplanar waveguide electrodes,the fabricated 4-μm-diameter PD exhibits ultra-flat frequency response and high saturation power.Integrated passive circuits including low-loss bias-tee and E-plane probe are designed to package the PD into a compact module with waveguide output.The packaged PD module has demonstrated a flat frequency response with fluctuations within±2.75 d B over a broadband of 140–220 GHz and a high saturated output power of-7.8 d Bm(166μW)at 140 GHz.For wireless communication applications,the packaged PD is used to implement 1-m free space transmission at carrier frequencies of 150.5 and 210.5 GHz,with transmission rates of 75 and 90 Gbps,respectively.展开更多
The electrochemical performances of cathode play a key role in the marine sediment microbial fuel cells(MSMFCs)as a long lasting power source to drive instruments,especially when the dissolved oxygen concentration is ...The electrochemical performances of cathode play a key role in the marine sediment microbial fuel cells(MSMFCs)as a long lasting power source to drive instruments,especially when the dissolved oxygen concentration is very low in seawater.A CTS-Fe^(3+)modified cathode is prepared here by grafting chitosan(CTS)on a carbon fiber surface and then chelating Fe^(3+)through the coordination process.The electrochemical performance in seawater and the output power of the assembled MSMFCs are both studied.The results show that the exchange current densities of CTS and the CTS-Fe^(3+)group are 5.5 and 6.2 times higher than that of the blank group,respectively.The potential of the CTS-Fe^(3+)modified cathode increases by 138 mV.The output power of the fuel cell(613.0 mW m^(-2))assembled with CTS-Fe^(3+)is 54 times larger than that of the blank group(11.4 mW m^(-2))and the current output corresponding with the maximum power output also increases by 56 times.Due to the valence conversion between Fe^(3+)and Fe^(2+)on the modified cathode,the kinetic activity of the dissolved oxygen reduction is accelerated and the depolarization capability of the cathode is enhanced,resulting higher cell power.On the basis of this study,the new cathode materials will be encouraged to design with the complex of iron ion in natural seawater as the catalysis for oxygen reduction to improve the cell power in deep sea.展开更多
Language output has positive effects on second language acquisition (SLA).The view this paper holds is that by finding out effective ways to promote language output,the quality of college English teaching will be impr...Language output has positive effects on second language acquisition (SLA).The view this paper holds is that by finding out effective ways to promote language output,the quality of college English teaching will be improved.展开更多
改性阳极可以显著提高海底微生物燃料电池的性能。利用2-羟基-1,4-萘醌(HNQ)和氧化石墨烯(GO)制备复合改性阳极,并研究其电化学性能。结果表明,GO/HNQ改性阳极的交换电流密度是空白电极的6.58倍,达到290.8 m A/m2。GO/HNQ改性使BMFC的...改性阳极可以显著提高海底微生物燃料电池的性能。利用2-羟基-1,4-萘醌(HNQ)和氧化石墨烯(GO)制备复合改性阳极,并研究其电化学性能。结果表明,GO/HNQ改性阳极的交换电流密度是空白电极的6.58倍,达到290.8 m A/m2。GO/HNQ改性使BMFC的最大功率密度达到346 m W/m2,是空白组的3.46倍。紫外检测结果表明,GO特征峰呈现显著红移,这与GO和HNQ之间的π-π堆积有关。最后提出改性阳极表面新的电子转移机理。展开更多
基金supported in part by National Key Research and Development Program of China(No.2022YFB2803002)National Natural Science Foundation of China(Nos.62235005,62127814,62225405,61975093,61927811,61991443,61925104 and 61974080)Collaborative Innovation Centre of Solid-State Lighting and Energy-Saving Electronics.
文摘This paper presents a wide-bandwidth back-illuminated modified uni-traveling-carrier photodiode(MUTC-PD)packaged with standard WR-5 rectangular waveguide for high-speed wireless communications.With optimized epitaxy structure and coplanar waveguide electrodes,the fabricated 4-μm-diameter PD exhibits ultra-flat frequency response and high saturation power.Integrated passive circuits including low-loss bias-tee and E-plane probe are designed to package the PD into a compact module with waveguide output.The packaged PD module has demonstrated a flat frequency response with fluctuations within±2.75 d B over a broadband of 140–220 GHz and a high saturated output power of-7.8 d Bm(166μW)at 140 GHz.For wireless communication applications,the packaged PD is used to implement 1-m free space transmission at carrier frequencies of 150.5 and 210.5 GHz,with transmission rates of 75 and 90 Gbps,respectively.
基金supported by the National Natural Science Foundation of China(No.22075262)。
文摘The electrochemical performances of cathode play a key role in the marine sediment microbial fuel cells(MSMFCs)as a long lasting power source to drive instruments,especially when the dissolved oxygen concentration is very low in seawater.A CTS-Fe^(3+)modified cathode is prepared here by grafting chitosan(CTS)on a carbon fiber surface and then chelating Fe^(3+)through the coordination process.The electrochemical performance in seawater and the output power of the assembled MSMFCs are both studied.The results show that the exchange current densities of CTS and the CTS-Fe^(3+)group are 5.5 and 6.2 times higher than that of the blank group,respectively.The potential of the CTS-Fe^(3+)modified cathode increases by 138 mV.The output power of the fuel cell(613.0 mW m^(-2))assembled with CTS-Fe^(3+)is 54 times larger than that of the blank group(11.4 mW m^(-2))and the current output corresponding with the maximum power output also increases by 56 times.Due to the valence conversion between Fe^(3+)and Fe^(2+)on the modified cathode,the kinetic activity of the dissolved oxygen reduction is accelerated and the depolarization capability of the cathode is enhanced,resulting higher cell power.On the basis of this study,the new cathode materials will be encouraged to design with the complex of iron ion in natural seawater as the catalysis for oxygen reduction to improve the cell power in deep sea.
文摘Language output has positive effects on second language acquisition (SLA).The view this paper holds is that by finding out effective ways to promote language output,the quality of college English teaching will be improved.
文摘改性阳极可以显著提高海底微生物燃料电池的性能。利用2-羟基-1,4-萘醌(HNQ)和氧化石墨烯(GO)制备复合改性阳极,并研究其电化学性能。结果表明,GO/HNQ改性阳极的交换电流密度是空白电极的6.58倍,达到290.8 m A/m2。GO/HNQ改性使BMFC的最大功率密度达到346 m W/m2,是空白组的3.46倍。紫外检测结果表明,GO特征峰呈现显著红移,这与GO和HNQ之间的π-π堆积有关。最后提出改性阳极表面新的电子转移机理。
