Multi-functional transparent electrode for reliable flexible perovskite solar cells

Han, Gill Sang,Lee, Seongha,Duff, Matthew Lawrence,Qin, Fen,Jiang, Minlin,Li, Guangyong,Lee, Jung-Kun Elsevier 2019 Journal of Power Sources Vol.435 No.-

<P><B>Abstract</B></P> <P>Multilayer MoO<SUB>x</SUB>/Ag/MoO<SUB>x</SUB> (DMD) films are found to be transparent conducting electrodes for use in extremely stable and highly bendable flexible perovskite solar cells (PSCs). The optical transparency and electric properties of DMD and its role as a top electrode of PSCs were studied by changing the thickness of the MoO<SUB>x</SUB> layer. Although the MoO<SUB>x</SUB> thickness was shown to have a negligible effect on the sheet resistance of DMD, the transmittance of visible light, selective carrier transport capability, and long-term stability of a device considerably depend on this factor. The sandwich structure of a 20-nm-thick MoO<SUB>x</SUB>, 7-nm-thick Ag, and 20-nm-thick MoO<SUB>x</SUB> exhibits a high transmittance and large photon–electron conversion rate of PSCs. In addition, PSCs using the DMD top electrode maintain 92% of their initial current density after 24 h of continuous operation owing to a UV light cut-off of the top illumination. Moreover, the overall structure of DMD blocks the diffusion of water and oxygen molecules from real environmental conditions. At the same time, the underlying/upper MoO<SUB>x</SUB> layer retards the degradation through a chemical reaction between Ag and the halide ions inside the cells, as well as foreign ions from outside the polluted atmosphere. When DMD is applied to flexible PSCs on Ti foil, the PCE reaches 14.5%, and mechanical integrity of the PSCs is maintained at a bending radius of 4 mm.</P> <P><B>Highlights</B></P> <P> <UL> <LI> MoO<SUB>x</SUB>/Ag/MoO<SUB>x</SUB> multilayer is used as a top electrode of perovskite solar cells. </LI> <LI> The multilayer electrode has multiple functions in real operation environment. </LI> <LI> 92% of the initial current density is maintained after 24 h continuous operation. </LI> <LI> The efficiency of flexible solar cells using MoO<SUB>x</SUB>/Ag/MoO<SUB>x</SUB> reaches 14.5%. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Role of sul2 Gene Linked to Transposase in Resistance to Trimethoprim/Sulfamethoxazole Among Stenotrophomonas maltophilia Isolates

Li-Fen Hu,Xi-Hai Xu,Haifei Yang,Ying Ye,Jia-Bin Li 대한진단검사의학회 2016 Annals of Laboratory Medicine Vol.36 No.1

Optimization of the Field Shaper Parameters in Electromagnetic Pulse Crimping of Cable

Fen-Qiang Li,Jishuai Jiang,Hongsong Cheng,Jianling Xu,Xiaohong Ge,Hui Li,Jun Zhao,Yang Ran 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.22 No.10

Crimping of wires to achieve a secure connection is one of the most critical challenges in fabrication of electronic circuit boards, automobiles, aviation, satellite and communication components. The electromagnetic pulse crimping process offers great potential to successfully address these challenges. In this paper, ANSYS/Multi physical software was used to first determine the electromagnetic force distribution on the terminal lug by analyzing the magnetic field in the electromagnetic pulse crimping process. The electromagnetic force was then imported into the ABAQUS/Explicit software as the boundary condition to calculate the deformation behavior of the terminal lug barrel and cable according to the stress–strain curve of the terminal material under high strain rate. The calculated deformation result was subsequently verified by experimental data. Three main parameters of the field shaper were analyzed to determine their influence on the crimping result; slit position, the inner diameter vertical dimension and the position relationship between the terminal lug and field shaper. Then using the empirical formula we calculated and verified the inner diameter vertical dimension of the field shaper. The model proved to be reliable. Deformation of the terminal was determined to be uneven along the circumference in the crimping area. For the type of terminal lug studied, an inner diameter vertical dimension of 10 mm proved to be optimum for increased strength of the crimped terminal connection. Allowing the terminal to protrude 1 mm from the field shaper resulted in a flatter crimped area and significant improvement in the quality of the crimped barrel surface. The empirical formula for calculating the inner diameter vertical dimension of the field shaper is reasonable and reliable, and the calculated measurement resulted in improved connection strength. The results of this research can be used to guide the electromagnetic pulse crimping of other terminal lug and cable types.

Mutations in the GyrA Subunit of DNA Gyrase and the ParC Subunit of Topoisomerase IV in Clinical Strains of Fluoroquinolone-Resistant Shigella in Anhui, China

Li-Fen Hu,Jia-Bin Li,Ying Ye,Xu Li 한국미생물학회 2007 The journal of microbiology Vol.45 No.2

In this research 26 Shigella isolates were examined by PCR and direct nucleotide sequencing for genetic alterations in the quinolone-resistance determining regions (QRDRs). We tested for the presence of qnr genes by PCR in 91 strains, but no qnr genes were found. The results did show, however, some novel mutations at codon 83 of gyrA (Ser→Ile) and codon 64 of parC (Ala64→Cys, Ala64→Asp), which were related to fluroquinolone resistance.

Evaluating optimum tilt angle for PV modules using solar radiation models in Wuhan, China

Fen. Li,Nianjun. Ma,Jinbin. Zhao,Keqing. Qu,Xingwu. Yang,Zhenghong. Chen 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

Four models are used to estimate the hourly solar radiation on 15 pieces of different tilted photovoltaic (PV) modules in Wuhan, China based on power and solar radiation data during a whole year. The optimum tilt angle (OTA) in Wuhan for yearly and semi-yearly adjustment was determined. Then it was determined that the best mode is the tilt angle of PV module adjusted every half a year. In semi-yearly adjustment, OTA in semi-year of winter and summer is found as 45°, 15°, respectively. Experimental results verify the theoretical calculated values of the OTA with high precision. Energy radio (ER) reveals PV modules with adjustment of tilt angle twice a year has a capability to improve nearly 7% in comparison with fixed type. The best model was chosen based on test results from statistical indicators. The statistical results demonstrate that among the studied models, Liu&Jordan model is the most accurate.

Characterization and function of a short peptidoglycan recognition protein from the Chinese oak silkworm, Antheraea pernyi

Li-Shang Dai,Cen Qian, LeiWang,Guo-Qing Wei,Qiu-Ning Liu,Yu Sun,Cong-Fen Zhang,Jun Li,Dong-Ran Liu,Bao-Jian Zhu,Chao-Liang Liu 한국응용곤충학회 2015 Journal of Asia-Pacific Entomology Vol.18 No.4

Peptidoglycan recognition proteins (PGRPs) are conserved proteins in animals from insects to mammals and play an important role in immune response by recognizing peptidoglycan on microbial surfaces. In this study, a PGRP gene from Antheraea pernyi, named Ap-PGRP-A, was isolated and characterized. Sequence analysis revealed that the full-length cDNA of Ap-PGRP-A was 961 bp, containing a 40 bp 5′-untranslated sequence, a 339 bp 3′-untranslated region and an open reading frame of 582 bp. This gene encoded a putative protein of 193 amino acid residues. Phylogenetic analysis indicated that Ap-PGRP-A had the closest protein sequence similarity to Antheraea mylitta PGRP. The recombinant protein was successfully expressed in Escherichia coli cells and a rabbit anti-Ap-PGRP-A antibody was also prepared. Real-time quantitative reverse transcription-PCR analysis showed that Ap-PGRP-A was extensively expressed in the fat body, midgut, hemocyte,malpighian tubule and epidermis of A. pernyi, especially in the fat body and midgut. The expression levels of Ap-PGRP-A were significantly up-regulated by three types of microorganisms, and Ap-PGRP-A expression was more sensitive in response to the Gram-negative bacterium E. coli than the Gram-positive bacterium Bacillus subtilis or the fungus Beauveria bassiana. These data indicate that Ap-PGRP-A may play a role in the innate immune responses of A. pernyi.

Comestible and temperature effects on the biological traits of fall armyworms, Spodoptera frugiperda

Li Fen,Wang Likui,Lu Rongcai,Peng Zhengqiang,Malhat Farag,Lyu Baoqian,Wu Shaoying 한국곤충학회 2021 Entomological Research Vol.51 No.10

Spodoptera frugiperda is considered a serious pest for many crops throughout the world. Here, we develop an easy and quick-to-prepare solid medium with multiple benefits, including reductions in cost, post-rearing waste, storage space, and labor, for rearing S. frugiperda larvae. The body length and weight at each development stage showed no differences with those of the corn leaves treatment group (P > 0.05). The development time of F0 generation from the first to adults stage was 51.27 ± 4.62 days when the larvae were reared on artificial diet, which is slightly longer than the 50.69 ± 4.56 days for those reared on corn leaves diet (P > 0.05). The temperature changes have no effect on body length and weight when the fall armyworms are reared on artificial diet, however, the influence of temperature change on development was more obvious. The development time was significantly longer at 18°C and shorter at 35°C than that at 25°C (P < 0.05). Furthermore, in the age-specific two-sex life table method, the life table parameters (i.e., r, λ, R0, GRR) significantly decreased at 18°C and 35°C compared with those at 25°C. The age–stage survival rate of S. frugiperda was higher on artificial diet at 25°C than 18°C, 35°C, and on corn leaves at 25°C in all stages. The 35°C temperature change had more influence on the age–stage survival than the other temperatures. This study provided ideal indoor breeding conditions for fall armyworm and sufficient materials for further indoor and outdoor research.

Comparative study of the microstructure of Ti-6Al-4V titanium alloy sheets under quasi-static and high-velocity bulging

Fen-Qiang Li,Jun Zhao,Jian-Hua Mo,Jian-Jun Li,Liang Huang 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.3

In order to reveal the high-velocity deformation mechanisms of Ti-6Al-4V titanium alloy sheets, the dynamic deformation behavior and the microstructure evolutions were compared with those under quasi-static case employing Scanning electron microscopy/Electron back-scattered diffraction (SEM/EBSD) and Transmission electron microscopy (TEM). The results indicated that the distribution of microhardness was uneven. The cause was determined to be the non-uniform material flow and dynamic loading. The grain sizes of the Ti-6Al-4V titanium alloy sheet were nearly the same under two conditions, but the grains were elongated under the dynamic loading compared with that observed in quasi-static forming. In high-velocity bulging, dislocation slip was the principle mechanism of plastic deformation of Ti-6Al-4V titanium alloy when deformation was small. As the strain increased, the twinning phenomenon was activated in addition to the dislocation cell structure. The twinning plane was determined to be the (10 11) plane.

Molecular characterization and functional analysis of two trehalose transporter genes in the cabbage beetle, Colaphellus bowringi

Li Jia-Xu,Cao Zhen,Guo Shuang,Tian Zhong,Liu Wen,Zhu Fen,Wang Xiao-Ping 한국응용곤충학회 2020 Journal of Asia-Pacific Entomology Vol.23 No.3

The trehalose, major blood sugar in insects, enhances stress resistance of diapausing individuals in adverse environment and provides an energy source for reproduction. Trehalose transporters (TRETs) play an important role in transport of trehalose from trehalose-producing tissues, e.g. fat body, to trehalose-consuming tissues. Although studies have shown that trehalose contributes to diapause and reproduction, the function of TRETs in these processes remains unclear. In this work, we cloned two TRET genes, TRET1a and TRET1b, from the cabbage beetle Colaphellus bowringi, which is capable of entering reproductive diapause under long-day conditions. We also analyzed the expression profiles of these two genes and investigated their potential roles in diapause and reproduction. The results suggested that both TRET1a and TRET1b belong to sugar-transporter and major facilitator superfamilies. Interestingly, TRET1a was highly expressed in the fat bodies of diapause-destined (DD) females but TRET1b was predominantly expressed in the ovaries of non-diapause-destined (NDD) females. Hormonal induction indicated that juvenile hormone induced TRET1b but repressed TRET1a at transcriptional levels. Methoprene-tolerant and Krüppel homolog 1 mediated the JH-suppressed TRET1a expression but were not involved in the regulation of TRET1b expression by JH. RNAi of TRET1a in DD females elevated the trehalose content in the fat bodies and suppressed the expression of a couple of genes related to stress resistance, which is a critical diapause trait. Knockdown of TRET1b in NDD females reduced the trehalose content in the ovaries but had no apparent effect on the ovary development and yolk deposition. These data suggest that TRET1a and TRET1b could regulate the trehalose content in specific tissues and may play potential roles in reproductive diapause in the females of C. bowringi. Introduction Diapause is a survival strategy for many insects in adapting to adverse environmental conditions (Tauber and Tauber, 1976; Tougeron, 2019). Diapause is a dynamic successive process that consists of diapause induction, preparation, initiation, maintenance, termination, and post-diapause quiescence (Kostal, 2006). Insects accumulate enormous nutrients such as sugars and lipids to enter diapause during diapause preparation phase (Hahn and Denlinger, 2007, 2011). The trehalose is the major hemolymph sugar in insects. The sugar not only provides source of energy but also protects proteins and cellular membranes from dehydration, desiccation, heat, cold, and oxidation (Elbein et al., 2003; Li et al., 2002; Richards et al., 2002; Wyatt and Kalf, 1957; Yancey, 2005; Zhu et al., 2008). Therefore, trehalose can play roles in reproduction and diapause by mediating energy supply and stress tolerance, respectively (Kamei et al., 2011; Lu et al., 2019; Xu et al., 2009).

Effects of sodium diacetate or microbial inoculants on aerobic stability of wilted rye silage

Li Yan Fen,Wang li li,Jeong Eun Chan,김학진,Ahmadi Farhad,김종근 아세아·태평양축산학회 2022 Animal Bioscience Vol.35 No.12

Objective: The primary goal was to identify the effectiveness of chemical or biological additives in delaying the deterioration of early-harvested wilted rye silage after exposure to air. Methods: Rye harvested as a whole plant at the early heading stage was wilted for 24 h. The wilted forage was divided into treatments including sodium diacetate (SDA) at 3 (SDA3) and 6 g/kg (SDA6), Lactobacillus plantarum (LP), L. buchneri (LB), or their equal mixture (LP+LB) at 1×106 colony-forming unit/g fresh matter. Results: After 60 d of conservation in 20-L silos, lactic acid was greater in LP and LP+LB silages than other treatments (102 vs 90.2 g/kg dry matter [DM]). Acetic acid was greatest in SDA6 (32.0 g/kg DM) followed by LB (26.1 g/kg DM) and was lowest in LP treatment (4.73 g/kg DM). Silage pH was lower with microbial inoculation and the lowest and highest values were observed in LP and untreated silages, respectively. After 60 d, neutral detergent fiber concentration was lowest in SDA6 silages, resulting in the greatest in vitro DM digestibility (846 g/kg DM). Aerobic stability was longest in SDA6 (176 h) followed by LB treatment (134 h). Instability after aerobiosis was greatest in LP silages (68 h), about 8 h less than untreated silages. After aerobic exposure, yeast and mold numbers were lowest in SDA6 silages, resulting in DM loss minimization. Exhaustion of acetic acid and lactic acid after aerobic exposure was lowest with SDA6 but greatest with untreated and LP silages. Conclusion: Treatment of early-cut wilted rye forage with SDA at 6 g/kg resulted in silages with higher feeding value and fermentation quality, and substantially delayed deterioration after aerobic exposure, potentially qualifying SDA at this load for promotion of silage quality and delaying aerobic spoilage of early-harvested (low DM) rye forage. Objective: The primary goal was to identify the effectiveness of chemical or biological additives in delaying the deterioration of early-harvested wilted rye silage after exposure to air.Methods: Rye harvested as a whole plant at the early heading stage was wilted for 24 h. The wilted forage was divided into treatments including sodium diacetate (SDA) at 3 (SDA3) and 6 g/kg (SDA6), <i>Lactobacillus plantarum</i> (LP), <i>L. buchneri</i> (LB), or their equal mixture (LP+LB) at 1×10⁶ colony-forming unit/g fresh matter.Results: After 60 d of conservation in 20-L silos, lactic acid was greater in LP and LP+LB silages than other treatments (102 vs 90.2 g/kg dry matter [DM]). Acetic acid was greatest in SDA6 (32.0 g/kg DM) followed by LB (26.1 g/kg DM) and was lowest in LP treatment (4.73 g/kg DM). Silage pH was lower with microbial inoculation and the lowest and highest values were observed in LP and untreated silages, respectively. After 60 d, neutral detergent fiber concentration was lowest in SDA6 silages, resulting in the greatest <i>in vitro</i> DM digestibility (846 g/kg DM). Aerobic stability was longest in SDA6 (176 h) followed by LB treatment (134 h). Instability after aerobiosis was greatest in LP silages (68 h), about 8 h less than untreated silages. After aerobic exposure, yeast and mold numbers were lowest in SDA6 silages, resulting in DM loss minimization. Exhaustion of acetic acid and lactic acid after aerobic exposure was lowest with SDA6 but greatest with untreated and LP silages.Conclusion: Treatment of early-cut wilted rye forage with SDA at 6 g/kg resulted in silages with higher feeding value and fermentation quality, and substantially delayed deterioration after aerobic exposure, potentially qualifying SDA at this load for promotion of silage quality and delaying aerobic spoilage of early-harvested (low DM) rye forage.