http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Flexible/Rechargeable Zn-Air Batteries Based on Multifunctional Heteronanomat Architecture
Lee, Donggue,Kim, Hyun-Woo,Kim, Ju-Myung,Kim, Ka-Hyun,Lee, Sang-Young American Chemical Society 2018 ACS APPLIED MATERIALS & INTERFACES Vol.10 No.26
<P>The increasing demand for advanced rechargeable batteries spurs development of new power sources beyond currently most widespread lithium-ion batteries. Here, we demonstrate a new class of flexible/rechargeable zinc (Zn)-air batteries based on multifunctional heteronanomat architecture as a scalable/versatile strategy to address this issue. In contrast to conventional electrodes that are mostly prepared by slurry-casting techniques, heteronanomat (denoted as “HM”) framework-supported electrodes are fabricated through one-pot concurrent electrospraying (for electrode powders/single-walled carbon nanotubes (SWCNTs)) and electrospinning (for polyetherimide (PEI) nanofibers) process. Zn powders (in anodes) and rambutan-shaped cobalt oxide (Co<SUB>3</SUB>O<SUB>4</SUB>)/multiwalled carbon nanotube (MWCNT) composite powders (in cathodes) are used as electrode active materials for proof of concept. The Zn (or Co<SUB>3</SUB>O<SUB>4</SUB>/MWCNT) powders are densely packed and spatially bound by the all-fibrous HM frameworks that consist of PEI nanofibers (for structural stability)/SWCNTs (for electrical conduction) networks, leading to the formation of three-dimensional bicontinuous ion/electron transport channels in the electrodes. The HM electrodes are assembled with cross-linked polyvinyl alcohol/polyvinyl acrylic acid gel polymer electrolytes (acting as zincate ion crossover-suppressing, permselective separator membranes). Benefiting from its unique structure and chemical functionalities, the HM-structured Zn-air cell significantly improves mechanical flexibility and electrochemical rechargeability, which are difficult to achieve with conventional Zn-air battery technologies.</P> [FIG OMISSION]</BR>
Donggu Im,Hong-Teuk Kim,Kwyro Lee IEEE 2009 IEEE transactions on microwave theory and techniqu Vol.57 No.11
<P>A resistive feedback differential low-noise amplifier (LNA) with enhanced loop gain is implemented as a part of a digital TV (DTV) tuner using a 0.18-mum CMOS process. A voltage buffer having higher gain, higher linearity, and lower noise figure (NF) than those of the conventional differential source follower (DSF), which is called the differential hybrid voltage buffer (DHVB) in this paper, is designed by combining the common source amplifier and source follower. By adopting the DHVB with optimized performance as a voltage buffer of the conventional resistive feedback differential LNA, the loop gain of the LNA can be increased. This leads to a highly linear resistive feedback LNA with higher gain and lower NF compared to the conventional resistive feedback LNA. For the wide gain range, the proposed LNA includes the variable gain function based on the resistive attenuator employing the T-switch. The measurement results of the proposed LNA exhibit a maximum gain of 16 dB and a gain range of 50 dB. At maximum gain, the LNA shows an average NF of 2.8 dB, a third-order input-referred intercept point of -1 dBm, a second-order input-referred intercept point of 40 dBm, and S11 of under -9 dB in a frequency range from 48 to 860 MHz. The power consumption is 30.6 mW at a 1.8-V power supply and the chip area is 0.25 mm<SUP>2</SUP>.</P>