The Potentials in Solar Cells for MEH-PPV Derivatives: Molecular Design and Performance Prediction

Xiaohua Xie,Xu Liu,Dan Zeng,Longfeng Zhao 대한화학회 2020 Bulletin of the Korean Chemical Society Vol.41 No.7

In this contribution, the polymer poly(2-methoxy-5(2?-ethyl-hexyloxy)-1,4-phenylene vinylene) (MEH-PPV) is researched at the aspect of electronic and structural properties to locate the relationships between structures and the experimental properties by employing DFT and TD-DFT method. The studied properties refer to the geometry features, absorption spectra, frontier molecular orbital properties, hole transport properties, and exciton dissociation ability at polymer/PC61BM interface. In addition, four MEH-PPV derivatives, MEH-PPV substituted with F atoms, are designed and studied through comparing with the properties of MEH-PPV. The results indicate that MEH-PPV has low HOMO levels and large hole transport property, which result in its preferable performance. Besides, the designed polymers are promising candidates as PSC donors due to better exciton dissociation ability and larger theoretical VOC owing to lower highest occupied molecule levels, in special, MEH-PPV-Fc has better hole transport properties than MEH-PPV due to smaller m*.

Numerical Study on Rotating Characteristics of Unsteady Flow Inner Pump-turbine in Pump Mode

Jun Yang,Tian Xie,Pavesi Giorgio,Xiaohua Liu,Jun Liu 한국유체기계학회 2018 International journal of fluid machinery and syste Vol.11 No.3

In order to investigate the formation of the rotating stall in diffuser of pump-turbine in pump mode, the unsteady flow with radial rotating characteristics before the occurrence of rotating stall are investigated by detached eddy simulation. The results indicate that the unsteady flow patterns which occur in the return channel both at full and part load conditions contain two periodical disturbances with frequencies St≈0.042 and St≈0.085, and the Strouhal number St is frequency normalized by blade passing frequency of impeller. These periodical disturbances not only influence the pressure field but also cause rotating characteristics in diffuser channels. One is composed of 4 cells propagating at 0.073 times of impeller rotating speed. The other one is made up of 3 rotating cells with 0.2 times of backward impeller rotating speed. Meanwhile, there are two radial rotating characteristics which contribute the spectra peak at blade pass frequency in diffuser. One is at the inlet of diffuser propagating at impeller rotating speed with 7 cells, and the other one contains 4 cells with about 1.75 backward impeller rotating speed.

2D FEM Based Fast Approach to Predict Electromagnetic Performances of a Variable-Speed FMaSynRM Considering Skewing Effects

Di Chong,Bao Xiaohua,Jiang Wei,Xie Bao 대한전기학회 2024 Journal of Electrical Engineering & Technology Vol.19 No.1

Skewing techniques have been widely used in the feld of the design of diferent types of electrical machines, because it can help to reduce the torque ripple, mitigate the electromagnetic noise and vibration, etc. To model the skewing efects in the electrical machine design accurately, the fnite element method is appreciated in both the academia and industry. To achieve a fast modelling of skewing efects, a novel 2D based approach to estimate the electromagnetic performances in the whole speed range for variable-speed electrical machines has been proposed in this paper, which is further improved from the traditional multi-slice method. Firstly, a series of simulations at diferent loads will be run to get the electromagnetic performances for the variable-speed machines. Secondly, based on the multi-slice method, the performance on diferent slices can be predicted from the results obtained from the existing simulations by coordinate transform and interpolation directly and no more extra simulations are needed. Thirdly, taking a ferrite magnet assisted synchronous reluctance machine (FMaSynRM) with skewing as an example, the electromagnetic performances including electromagnetic torque, stator current and voltage, efciency map are compared in detail by both the proposed method and experiments.

Molecular mechanism of poisoning to honeybees (Apis mellifera L.) after ingestion of Camellia oleifera nectar

Wang Yang,Liu Xiaohua,Wang Yiming,Jin Mingxia,Xie Guai,Zhong Qiuping,Yu Ailin 한국응용곤충학회 2024 Journal of Asia-Pacific Entomology Vol.27 No.1

To explore the molecular mechanism of honeybees (Apis mellifera L.) poisoning death by ingestion of Camellia oleifera nectar, feeding experiments were designed to investigate the poisoning effects. Observed the develop ment process of poisoning symptoms, and collected bees at key experimental nodes for transcriptome sequencing analysis. The results showed that the first poisoning symptom was observed within 0.5 h after ingestion of Camellia oleifera nectar, with death occurring as early as 2 h post-ingestion and all honey bees dying within 4 h. There were four stages in the development of poisoning symptoms: normal flying, crawling (abdominal swelling, inability to fly normally), fluttering (inability to crawl normally), and death. Transcriptome sequencing analyzed the causes of poisoning death indicated that honey bee poisoning occurred with the transduction of dietary restriction signals into cells, resulting in the down-regulated expression gene elements that ensure cell health and inhibit apoptosis, including intracellular NAD+-dependent protein deacetylase sirtuin 1, insulin-like growth factor 1, and heat shock proteins. At the same time, the expression of cysteinyl aspartate specific proteinase 7, which protects programmed cell apoptosis, was also downregulated, resulting in the rapid and disorderly deaths of a large number of cells in individuals in a short period of time, and eventually leading to bees fatality.

cDNA Cloning and Expression Analysis of a Novel Human F-Box Only Protein

Haipeng Cheng,Yushu Ma,Xiaohua Ni,Min Jiang,Lingchen Guo,Wei Jin,Weiwen Xu,Gentao Cao,Chaoneng Ji,Kang Ying,Shaohua Gu,Yuhong Ma,Yi Xie,Yumun Mao 한국분자세포생물학회 2002 Molecules and cells Vol.14 No.1

F-box proteins are an expanding family of eukaryotic proteins that are characterized by an approximately 40 amino acid motif. Some F-box proteins are critical for the controlled degradation of cellular regulatory proteins. During a large-scale sequencing analysis of a human fetal brain cDNA library, we isolated a cDNA clone that encodes a novel F-box protein. It showed a 90.0% identity with the previously isolated mouse F-box protein16 at the amino acid level. Northern blot analysis showed no detectable expression, while re-verse transcription-polymerase chain reaction analysis indicated that FBXO16 was expressed in the heart, spleen, and colon. By mapping, we localized the FBXO16 gene to the human chromosome 8p12. The FBXO16 gene consisted of 9 exons that spanned 67,816 bp of human genomic DNA.

Elevated TRAF4 expression impaired LPS-induced autophagy in mesenchymal stem cells from ankylosing spondylitis patients

Jinteng Li,Peng Wang,Zhongyu Xie,Rui Yang,Yuxi Li,Xiaohua Wu,Hongjun Su,Wen Deng,Shan Wang,Zhenhua Liu,Shuizhong Cen,Yi Ouyang,Yanfeng Wu,Huiyong Shen 생화학분자생물학회 2017 Experimental and molecular medicine Vol.49 No.-

Ankylosing spondylitis (AS) is a type of autoimmune disease that predominantly affects the spine and sacroiliac joints. However, the pathogenesis of AS remains unclear. Some evidence indicates that infection with bacteria, especially Gram-negative bacteria, may have an important role in the onset and progression of AS. Recently, many studies have demonstrated that mesenchymal stem cells (MSCs) dysfunction may contribute to the pathogenesis of many rheumatic diseases. We previously demonstrated that MSCs from AS patients exhibited markedly enhanced osteogenic differentiation capacity in vitro under non-inflammatory conditions. However, the properties of MSCs from AS patients in an inflammatory environment have never been explored. Lipopolysaccharide (LPS), a proinflammatory substance derived from the outer membrane of Gram-negative bacteria, can alter the status and function of MSCs. However, whether MSCs from AS patients exhibit abnormal responses to LPS stimulation has not been reported. Autophagy is a lysosome-mediated catabolic process that participates in many physiological and pathological processes. The link between autophagy and AS remains largely unknown. The level of autophagy in ASMSCs after LPS stimulation remains to be addressed. In this study, we demonstrated that although the basal level of autophagy did not differ between MSCs from healthy donors (HDMSCs) and ASMSCs, LPS-induced autophagy was weaker in ASMSCs than in HDMSCs. Specifically, increased TRAF4 expression in ASMSCs impaired LPS-induced autophagy, potentially by inhibiting the phosphorylation of Beclin-1. These data may provide further insight into ASMSC dysfunction and the precise mechanism underlying the pathogenesis of AS.